Pellagra suffer, US South, early 20 th century
Structure of niacinamide and inclusion within NAD molecule

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Abstract

Niacinamide (also known as nicotinamide,

3-pyridinecarboxamide) is the physiologi-

cally active course of niacin or vitamin B3, the

deficiency of which results in the nutritional

disease pellagra with distinct cutaneous

manifestations. Since its discovery and iso-

lation, a host of dermatological therapeutic

benefits and mechanisms have besides been

ascribed to this essential water-soluble vit-

amin when used every bit a topical agent. These in-

clude its apparent role as an anti-acne ac-

tive, an upwardly-regulator of epidermal sphingo-

lipid synthesis, an up-regulator of markers of

epidermal differentiation and dermal prolif-

eration (with concurrent stratum corneum

barrier benefits), and as a moderator of pho-

toimmunesuppression and accompanying

tumor genesis. More recently, fresh evi-

dence points to a office in modifying the cos-

metic advent of skin through suppres-

sion of epidermal melanosome transfer with

subsequent event on skin pigmentation and

a role in modifying epidermal surface topo-

graphy. The mechanisms for these cutane-

ous effects are nonetheless unclear. Nevertheless, since

niacinamide is an important precursor of

NADH and NADPH, it has been postulated

that topical application of niacinamide can

promote this reported broad spectrum of

activity through local correction of homeo-

static remainder of these ii nucleotide coen-

zymes. As there has been a dramatic in-

pucker in research into and utilise of niacin-

amide in recent years, this review will cover

the current scope of knowledge of this im-

portant vitamin, including mechanistic un-

derstanding and cutaneous physiological

action.

History of Niacinamide

Niacinamide is the amide of vitamin B3, also

known by the pseudonym »Vitamin PP«, that

is, »Pellagra-Preventive«. The name is not

without meaning. The first case of pellagra

was reported in the U.S. in 1902; four

decades of a pellagra epidemic followed

during which, in states due south of the Potomac

and Ohio rivers, some three million cases and

100,000 deaths were reported [1]. Pellagra

patients presented with a variety of debili-

tating symptoms including, significantly, a

spectrum of cutaneous lesions. Tragically,

this led to the public exclusion of thousands

of victims, who came nearly exclusively

from poor, rural, working-form families who

fed themselves on a bland staple diet of

cornmeal, molasses and fatback. Joseph

Goldberger, a Hungarian emigrant who es-

tablished himself equally a renowned clinical epi-

demiologist, reversed steadfast medical

opinion that pellagra was an infectious,

communicable illness. He proved that sim-

ple dietary supplementation could both pre-

vent and cure pellagra. In 1927, after 13 years

of work, Goldberg persuaded the American

Ruddy Cross to distribute stale yeast to Mis-

sissippi overflowing victims and, thus, prevented a

further devastating epidemic. It was not un-

til 1937 that nicotinic acrid and its derivatives

(including niacinamide) were shown to be

the elusive »PP« factor. By 1945, Goldber-

ger's legacy was permanent; public educa-

tion had changed forever the poor diet of the

Due south and pellagra was eliminated in the

The states.

Physiological Role of Niacinamide

The substituted pyridine derivative niacin-

amide is an essential constituent of the oxi-

doreduction coenzymes nicotinamide ade-

nine dinucleotide (NAD) and nicotinamide

adenine dinucleotide phosphate (NADP)

(Fig. two). During glycolysis and the TCA bike,

10 molecules of NAD+ (per molecule of glu-

cose) are reduced to ten NADH by the trans-

fer of a hydride ion to the iv-position of the

niacinamide band. The hydride ion of NADH

serves effectively as an energy storage unit,

giving up a pair of loftier-energy electrons to

the mitochondrial electron transport chain

when needed. In this procedure of oxidative

phosphorylation, electron pairs are trans-

ferred from NADH to a final acceptor (oxy-

gen) via a series of electron carriers. This

transfer of electrons is thermodynamically

A Review of the Range of Effects of

Niacinamide in Human Pare

Paul J. Mattsone) , John E. Oblongii) and Donald L. Bissett2)

Keywords: Niacinamide, nicotinamide, skin, ceramide, ageing, differentiation, barrier

IFSCC Magazine – vol. v, no four / 2002

ane) The Procter & Risk Visitor, Rusham Park Technical Centre, Egham, Surrey, Uk

Email: matts.pj@pg.com

2) Miami Valley Laboratories, Cincinnati, Ohio, Us

Fig. 1: Pellagra suffer, US South, early on 20th

century

The authors acknowledge the Waring Historical

Library of the Medical University of South Caroli-

na, Charleston, SC

286

favorable, i.due east., ∆G is negative, and is coupled

to the pumping of protons out of the mito-

chondrial matrix. The flow of protons dorsum

into the matrix, in plough, catalyses the pro-

duction of ATP by F0 FaneA TP-synthase. Total

energy yield (∆G') for this procedure is high

(–52.7kcal).

Whereas NADH is involved in catabolism,

NADPH tends to serve equally an electron (hy-

dride ion) donor in anabolic processes, that

is, biosyntheses. For case, NADPH is the

reducing co-factor used past fat acid syn-

thetase in lipid biosynthesis and by desmo-

lases and hydroxylases in steroid biosynthe-

sister.

Nicotinamide Coenzymes in Peel

are Depleted with historic period; Niacin-

amide tin Help Normalize this Im-

residual

NADH and NADPH tin, thus, be viewed every bit

cardinal energy »currency« units within

cells, driving the metabolism of cells involv-

ed in both catabolic and anabolic process-

es. In that location is an increasing pool of evidence

for a refuse in systemic and intracellular

concentrations of these two coenzymes

with historic period in human and animal models [2,iii,4]

and recent new information appear to confirm this.

Oblong et al. [five] established human dermal

fibroblast jail cell lines from a 7-twelvemonth old and a

72-yr onetime and used these to measure out en-

dogenous NADPH/NADP+ ratios and total

NADPH + NADP+ levels. It was found that

fibroblasts from the aged donor independent

decreased NADP redox ratios and total

NADPH + NADP+ levels relative to those

from the young donor (51% and 28% respec-

tively). It does appear, therefore, that there

is a reduction in nicotinamide coenzymes

associated with senescence.

Importantly, Oblong et al. [5] as well found that

supplementation of human dermal fibroblast

cultures derived from elderly donors with

fourteenC-niacinamide and xivC-nicotinic acid

(niacinamide precursor) increased intracel-

lular concentrations of NADPH. It appears

that a localized supply of niacinamide, there-

fore, can be utilized past anile cutaneous cells

to restore intracellular nicotinamide coen-

zyme homeostasis.

It is worth noting, however, that despite the

efficacy noted to a higher place, nicotinic acrid (niacin)

produces a well-documented cutaneous va-

sodilatation (»flushing«) when applied to-

pically. Niacin, therefore, presents a chal-

lenge to corrective applications; at that place are no

such bug with the apply of niacinamide.

Aged Fibroblasts Secrete Less

Collagen than Young Cells;

Niacinamide can Stimulate New

Collagen Synthesis

Oblong et al. [5] used 14C-proline to monitor

incorporation of label into collagen protein

secreted from cultured human dermal fibro-

blasts taken from a young (vii-year old) and

aged donor (72-yr former). xiv C-hydroxyproline

(equally a marking of newly-synthesized secreted

collagen) and 14 C-proline (every bit a marker of to-

tal protein) were extracted, separated and

quantified using HPLC equipped with a ra-

diometric detector. Results indicated firstly

that dermal fibroblasts from an aged donor

secreted significantly (p<0.05) less collagen

than those from a immature donor and, further-

more, that NADPH / NADP redox ratios were

also lower (p<0.05) in fibroblasts from the

anile donor (results were normalized to the

cell number from the corresponding culture

well). Secondly, it was found that supple-

mentation of the aged cell civilization with

niacinamide produced significant increases

in full collagen secreted (past 54%), full pro-

tein secreted (past 41%) and also in the num-

ber of cells (by 20%), relative to a vehicle

command. Chiefly, in that location was also a signif-

icant 35% increase in the collagen / full pro-

tein ratio (relative to a vehicle command), indi-

cating some specificity for collagen biosyn-

thesis and secretion. These data propose,

therefore, that handling with niacinamide

would have a positive impact on the dermal

compartment, both in terms of its connective

tissue and gel matrix components. These

effects would be of detail significance in

aged and photodamaged skin.

Niacinamide Up-regulates Epider-

mal Ceramide Synthesis with Con-

electric current Epidermal Barrier Benefits

Ceramides are now known to play a cardinal

function in the structural and functional integrity

of the stratum corneum barrier office. A

subtract in ceramide fraction has been re-

ported in anile and atopic skin [6]. Tanno et

al. showed that in cultured human epidermal

keratinocytes, niacinamide could induce upwards

to a 5-fold upward-regulation in ceramide syn-

thesis (p<0.05) in a dose-dependent style

[7]. Further work by the same grouping [eight]

showed up-regulation of other sphingolipid

fractions (glucosylceramide and sphingo-

myelin) as well as free fatty acrid and cho-

lesterol synthesis (by 2.3 and ane.5-fold, re-

spectively). The workers proposed a mech-

anism for these observations based on in-

creased levels of intra-cellular acetyl-CoA

(the forerunner mutual to epidermal lipid

synthesis) and increased expression of ser-

ine-palmitoyltransferase. Tanno et al. [8] al-

and then showed that these in-vitro results had

clinical significance in-vivo. Topical applica-

tion of a vehicle containing 2% niacinamide

IFSCC Mag – vol. 5, no 4 / 2002

Fig. two: Structure of niacinamide and inclusion within NAD molecule

287

to dry lower legs over 4 weeks induced a

measurable meaning increase (p<0.05) in

recovered stratum corneum ceramide and

free fat acid lipid fractions, vs. a vehicle

control. This was accompanied by a signifi-

deceit reduction (p<0.05) in TEWL vs. vehicle

control (–27%). Similar significant reduc-

tions in TEWL vs. a vehicle control were not-

ed also by Ertel et al. [ix] later utilize of a mois-

turizing vehicle containing 2% niacinamide.

Furthermore, they also noted that this posi-

tive bulwark issue was accompanied by an

increase in stratum corneum turnover rate

(as measured past dansyl chloride analysis). Fi-

nally, Draelos et al. [10] treated 48 female person

subjects with stage I/II rosacea with a mois-

turizing vehicle containing ii% niacinamide

for 4 weeks and demonstrated a meaning

improvement in global status (assessed)

in 96% of the subjects at week 4. They de-

monstrated, in one case over again, that this clinical

benefit was accompanied by a meaning

improvement in stratum corneum barrier

office.

It appears that topical niacinamide is able to

augment the barrier backdrop of the pare,

with accompanying clinically relevant ben-

efits, by up-regulating endogenous biosyn-

thesis of epidermal sphingolipids, in partic-

ular, ceramides.

Niacinamide Upwardly-regulates

Biosynthesis of Markers of

Keratinocyte Differentiation

Oblong et al. [5] cultured normal human epi-

dermal keratinocytes to near-confluency

and then supplemented the medium with

niacinamide. Following a 24h incubation,

cells were counted, harvested and prepared

for assay for involucrin (by ELISA) and filag-

grinning (by an immunoblot procedure). Results

showed firstly a significant increase (p<0.05)

in the number of niacinamide-treated NHEK

relative to a vehicle control. Secondly, ni-

acinamide-treated NHEK showed an upwardly-

regulation of both involucrin and filaggrin

biosynthesis vs. that induced by a vehicle

control (by 45% and 100% respectively).

These two proteins are both disquisitional to the

differentiation procedure and the formation of

fully integral keratinized corneocytes; filag-

grin plays a vital office in aggregation and

alignment of keratin tonofilaments in granu-

lar cells and involucrin is an essential pre-

cursor in the germination of the insoluble

cornified envelope surrounding terminal

keratinocytes. In other words, niacinamide

has been shown to both stimulate basal epi-

dermal keratinocytes and to up-regulate

biosynthesis of epidermal intermediates

critical to the formation of a fully functioning

stratum corneum. This may exist due to in-

creased intracellular levels of reduced

nicotinamide coenzymes initiated by topical

niacinamide. These furnishings would be ex-

pected to have a significant positive touch

on ageing epidermal tissue in-vivo .

Niacinamide Helps Prevent

UV-Induced Deleterious Molecu-

lar and Immunological Events

Shen et al. [11] demonstrated the ability of

niacinamide to protect cultured normal hu-

man keratinocytes confronting reactive oxygen

species induced by UVC irradiation or expo-

sure to hydrogen peroxide. They observed

significant (p<0.05) dose-dependent attenu-

ation of apoptotic morphological changes, a

decrease in p53 induction and a reduction in

Deoxyribonucleic acid ladders for niacinamide-treated cells

vs. those treated with a vehicle control.

These information are consistent with work in ani-

mal models [12] demonstrating clearly the

ability of niacinamide to significantly reduce

both consecration of photocarcinogenesis and

photoimmunesuppression. The mechanism

by which niacinamide exerts these furnishings is

not yet clear.

Niacinamide Inhibits Transfer of

Melanosomes from Melanocytes

to Keratinocytes

Boissy et al. [13] used co-cultures of human

melanocytes and keratinocytes to investi-

gate the ability of niacinamide to reduce sus scrofa-

mentation in human skin. Use of immuno-

linked dyes specific for each prison cell type en-

abled separate counts of keratinocytes,

melanocytes and keratinocytes containing

transferred melanosomes to be performed.

The workers institute meaning inhibition

(p<0.05) of melanosome transfer to keratino-

cytes from melanocytes incubated in the

presence of niacinamide (past 25-45%). It was

also confirmed that niacinamide had no in-

hibitory effect on melanocyte tyrosinase

activity. These data suggest that treatment

of human pare in-vivo with topical niacin-

amide would lead to a reduction in pigmen-

tation with time via this novel, elegant mech-

anism.

Niacinamide Reduces Man

Skin Hyperpigmentation

Hakozaki et al. [14] performed ii studies

demonstrating the consequence of niacinamide on

skin hyperpigmentation in-vivo . In the first,

18 female Japanese subjects with hyperpig-

mented facial spots were treated for viii

weeks with a vehicle containing 5% niacin-

amide vs. a vehicle command in a dissever-confront de-

sign. Pigmented spots were qualified and

quantified via algorithmic analysis of high-

resolution digital images and subjective

grading of images. Results of image analysis

showed that 5% niacinamide had induced a

significant (p<0.05) reduction in spot area at

the 4 and 8 week time-points (vs. vehicle

control), accompanied by a significant re-

duction (p<0.05) in graded visible spot pig-

mentation at 8 weeks (vs. vehicle control). In

the second study, 120 female person Japanese sub-

jects with facial tanning were assigned to ii

of 3 treatments (SPF 15 sunscreen moistur-

izer, 2% niacinamide in SPF 15 sunscreen

moisturizer and a vehicle control). Subjects

applied treatments split-face up for 8 weeks. In

this written report overall skin lightness was as-

sessed by assay of digital images and by

subjective grading. Results of epitome analy-

sister showed a pregnant (p<0.05) increment in

skin lightness vs. the sunscreen moisturizer

and vehicle control at the 4 and half dozen calendar week fourth dimension-

points, accompanied by a significant

(p<0.05) increase in graded visible skin light-

ness vs. vehicle command at four weeks. These

in-vivo data appear to confirm, therefore,

that the inhibitory part of niacinamide in

melanosome transfer noted in-vitro [13],

does indeed interpret to a significant effect

on hyperpigmentation in-vivo .

Regulation of Sebaceous Lipid and

Acne past Niacinamide

To pical niacinamide in the form of a com-

mercial 4% gel (Papulex® ) has been shown

to provide potent anti-inflammatory activity

in the handling of acne vulgaris. Shalita et

al. [xv] institute that subsequently 8 weeks of usage,

82% of subjects with inflammatory acne

showed an improvement in global evalua-

tion, with a pregnant reduction in papules /

pustules (–60%) and acne severity (–52%).

Indeed, many practitioners use the treat-

ment citing a combination of efficacy and

lack of bacterial-resistance. Shalita et al.

[xv] and others postulate that niacinamide

IFSCC Magazine – vol. 5, no iv / 2002

288

may act via its apparent antihistaminic ef-

fect, activity every bit an electron scavenger, or its

inhibition of 3'-5' cyclic-AMP phosphodi-

esterase activity.

Recent data, however, appear to demon-

strate an altogether more cardinal part

for topical niacinamide in acne handling.

Biedermann et al. [sixteen] used feasible human fa-

cial biopsies (from confront-lift surgery) to mea-

sure the issue of niacinamide on sebaceous

lipogenesis. Cultured biopsies were treated

with niacinamide or trans-retinoic acid (tRA)

for 4 days, after which they were incubated

with 14 C-acetate. Lipid components were

later on isolated, fractionated and

identified using analytical TLC and radiome-

endeavor. Niacinamide produced significant dose-

dependent reductions in total sebaceous

lipogenesis (–42% at 25 mM [p<0.01]). Fur-

thermore, the reduction induced by 25 mM

niacinamide was equivalent to that pro-

duced by 1 µM tRA (–32% [p=0.01]). When

discrete lipid classes were identified and

quantified, it was found that niacinamide

had produced marked reductions in both

triglyceride and fat acid synthesis vs. the

control (–52% and –46% respectively for 25

mM niacinamide [p<0.05]). It is now known

that triglycerides correspond past far the largest

proportion of sebaceous gland lipid (50-

60%); the observed effect of niacinamide on

total lipogenesis is, therefore, probably at-

tributable to triglyceride reduction.

This has important implications for acne

pathogenesis. It is accepted that acne is a

disease involving the pilosebaceous duct

and Propionibacterium acnes. Despite the

on-going debate every bit to the verbal interplay of

these factors, information technology is without doubt that a sig-

nificant reduction both in total sebaceous

lipid bulk and in the triglyceride fraction

would be expected to impact positively

acne-form skin.

Niacinamide Exerts Multiple

Benefits on the Advent of

Ageing / Photodamaged Skin,

In-vivo

Bissett et al. [17] studied the effects of topi-

cal niacinamide in ageing human facial skin

in two double-blinded clinical studies. In the

first, twoscore female person subjects aged 35 - sixty applied

a vehicle and vehicle containing five% niacin-

amide (randomized split-face up) for 12 weeks.

High-resolution digital images were taken at

baseline, 4, 8 and 12 weeks and texture and

hyperpigmentation were evaluated by

judges (comparing bullheaded-coded image pairs,

baseline vs. another treatment time-bespeak).

Judges were able to perceive a meaning

comeback in peel texture advent at

4 weeks (p<0.1) and 12 weeks (p<0.05) and a

significant comeback in hyperpigmented

spot appearance by 8 weeks (p<0.05) (Fig. 3) .

In a second study, female subjects aged 35-

lx applied blind-coded products (vehicle

control and vehicle containing v% niacin-

amide; n=88) split-face for eight weeks. Skin tex-

ture appearance was assessed every bit above.

The niacinamide-containing handling pro-

vided a significant improvement in skin tex-

ture appearance relative to the vehicle con-

trol at the 8 week time-point, confirming the

results of the offset report.

This effect on pare surface texture is consis-

tent with that noted in a 10-week clinical

study where Matts & Solechnick [18] used

multiple-bending reflectance spectrophoto-

metry to mensurate the diffuse component of

skin reflection. They noted a pregnant in-

pucker in the diffuse component of 5%

niacinamide-treated dorsal paw peel vs.

vehicle control after 10 weeks of treatment

(p<0.05), consequent with significant blind

cocky-rated preferences for texture announced-

ance over vehicle control (p<0.05). This

modify was consistent with a shift in texture

distribution towards the effectively, anisotropic

features characteristic of younger pare.

Niacinamide is Delivered Effec-

tively from a Range of Vehicles

and Demonstrates Fantabulous Skin

Compatibility

Franz [19] determined niacinamide absorp-

tion in-vitro through full-thickness abdomi-

nal pare mounted in menstruation-through diffusion

cells. Franz used acetone as a carrier and

found 28.8% of the starting dose in the re-

ceptor medium at 24 h. Delivery of niacin-

amide (ii-20%) from a range of cosmetic for-

mulae (including moisturizers, foundations

and lipsticks) was studied using a modified

in-vitro Franz period-through prison cell technique

[20]. For formulae containing 2% niacin-

amide, approximately ten% of the starting

dose was detected in the receptor medium

at 48 h. Importantly, these studies highlight-

ed the apparent independence of niacin-

amide penetration charge per unit from diverse vehicle

matrices.

The Cosmetic Ingredient Review Good Pan-

el report for niacinamide [21] details a very

wide range of cutaneous tolerance studies

confirming the fantabulous profile of niacin-

amide equally a cosmetic skin intendance ingredient.

Conclusion

Niacinamide, therefore, has been shown to

be a cosmetic ingredient with an extraordi-

IFSCC Mag – vol. 5, no four / 2002

Baseline 12 Weeks

Fig. iii: Same subject area at baseline and after 12 weeks of topical handling with 5% niacinamide

289

nary breadth and history of cutaneous ben-

efits. Information technology is thought that its fundamental part as

a precursor of reduced nicotinamide coen-

zymes such as NADH and NADPH is pivotal

to its observed effects. It displays distinct

advantages over other ingredients with sim-

ilar benefits, such every bit retinol, in that it is well

tolerated, and is not bailiwick to oxidation or

photolysis. In brusk, the multiplicity of effects

and formulation benefits seen with niacin-

amide make it an ideal choice for a diverseness of

corrective products targeting young and old

skin alike.

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IFSCC Magazine – vol. five, no 4 / 2002

... The enriched formulation of the acne stress control serum contains a wide diverseness of compounds that make it useful for the treatment of acne-prone skin but besides for the recent maskne mechanical course. In particular, a key office is played by ceramide's mixture, Niacinamide, x-Hydroxydecanoic acid (10-HDA) and Sebacic acid [26][27][28]. ...

... The formulation contains a constructed blend of omega hydroxy acids, sebacic and hydroxy-decanoic acids (ten-HAD) that mimics the composition of royal jelly in controlling and reducing backlog sebum production [27,28]. Amid the main active ingredients, Niacinamide (4%) has anti-inflammatory properties, Ceramides meliorate bulwark part, and Dimethylmethoxy Chormanol provides antioxidant protection to eliminate irritating metabolites caused by acne-related sebum production [26]. Emollients aid to soften the external layer of the skin, increasing the power of the skin to concord water and playing an important function in conferring peculiar rheological properties [32]. ...

(1) Background: Acne is a widespread skin disease, particularly among adolescents. Following the COVID-xix pandemic and the utilize of masks, the trouble has been affecting a greater number of people, and the attention of the pare care beauty routine cosmetics has been focused on the "Maskne", caused past the sebum excretion rate (SER) that stimulates microbial proliferation. (2) Methods: the present study was focused on the rheological characterization and quality assurance of the preservative system of an anti-acne serum. The biological effectiveness (cytotoxicity—peel and eye irritation—antimicrobial, biofilm eradication and anti-inflammatory activeness) was evaluated in a monolayer cell line of keratinocytes (HaCaT) and on 3D models (reconstructed human being epidermis, RHE and homo reconstructed corneal epithelium, HCE). The Cutibacterium acnes, as the most relevant acne-inducing bacterium, is chosen as a pro-inflammatory stimulus and to evaluate the antimicrobial activity of the serum. (three) Results and Conclusions: Rheology allows to simulate serum behavior at rest, extrusion and awarding, and then the serum could be defined as having a solid-similar beliefs and being pseudoplastic. The preservative organisation is in compliance with the criteria of the reference standard. Biological effectiveness evaluation shows non-cytotoxic and irritant behavior with a practiced antimicrobial and anti-inflammatory activity of the conception, supporting the effectiveness of the serum for acne-prone skin treatment.

... In addition to these primary materials, secondary anti-oxidants and barrier improvement materials were besides included. Niacinamide [37] and caffeine [38] both accept antioxidant properties. Both niacinamide [37] and panthenol [39] improve skin hydration and skin barrier, thus reducing the tissue stress associated with poor barrier. ...

... Niacinamide [37] and caffeine [38] both have antioxidant properties. Both niacinamide [37] and panthenol [39] ameliorate skin hydration and skin barrier, thus reducing the tissue stress associated with poor barrier. As effective as these materials are intrinsically, effective scalp delivery vehicles were developed to enable the realization of these activities. ...

  • Michael Grand. Davis
  • Melissa Piliang
  • Wilma F Bergfeld Wilma F Bergfeld
  • James R. Schwartz

Objective Increasing hair fullness is a global unmet need for many men and women. An approach to the trouble is to decrease hair fall or shedding by reducing scalp stratum corneum oxidation and bulwark damage to increase hair retention. This report evaluated a combination of functional antioxidants and barrier-enhancing cosmetic ingredients to improve scalp status thereby enabling stronger pilus anchorage and longer retention. Methods Male and female subjects with normal scalp status and self-perceived hair thinning participated in a 24-week, double-blind, placebo-controlled, randomized clinical study assessing either a regimen of handling shampoo and leave-on treatment containing functional antioxidant and barrier-enhancing agents or an identical placebo chassis shampoo control. The functional ingredients were piroctone olamine, zinc pyrithione, zinc carbonate, niacinamide, panthenol, and caffeine. At baseline and later 8, xvi, and 24 weeks of production use, several measurements were taken: hair shedding, total hair count (by phototrichogram), hair samples, TEWL, and evaluation of biomarkers of scalp and pilus atmospheric condition. Subjects besides completed self-assessment questionnaires. Results Statistically pregnant furnishings for functional ingredient-containing treatment regimen versus a placebo control shampoo formulation were observed for reduced hair shedding, increased total hair count, reduced TEWL, and improvement in scalp biomarker values. Subjects also noticed these improvements assessed via cocky-assessment questionnaires. Conclusions These results plant that use of functional antioxidant and barrier-enhancing agents to farther ameliorate scalp condition tin can enable a reduction in hair shedding and thus an increase in perceived hair fullness. The underlying improvements in scalp condition suggest the hair benefits were achieved as a consequence of improved scalp skin barrier and scalp condition leading to a viable preventative approach for pilus thinning.

... Niacinamide (Nam; aka nicotinamide, vitamin B 3 ) has been used for decades in cosmetic and pharmaceutical products for the treatment of acne, photoageing attributes and barrier integrity improvement. [6][7][8] It has been reported that Nam can protect cells from oxidative stress, UV-induced immunosuppression and metabolic disruption. [9][ten][11] Mechanistically, it has go credible that Nam tin can have a significant impact on numerous processes associated with skin homeostasis and ageing. ...

... 3 Over the by few decades, Nam has get an important molecule in cosmetic and pharmaceutical products for the treatment of acne, peel photoageing attributes, and barrier integrity comeback. [6][seven][8] Nam has been reported to protect cells from oxidative stress, metabolic disruption, and inflammation. 9,10 Relevant to protecting from environmental insults, Nam has besides been shown to inhibit acute and chronic damaging effects of UV exposure on pare. ...

Background Macromolecules in skin cells are damaged when exposed to ecology stressors, leading to disrupted cellular office and homeostasis. While epidermal turnover can eliminate some of this damage, autophagy tin can rapidly remove these lacking components. Niacinamide (Nam) is known to induce autophagy and optimizing formulations to maximize this response could provide improved homeostasis in stressed peel. Objective To decide (i) whether Nam can induce autophagy related five (ATG5), an autophagy marking, in homo keratinocytes and (2) whether optimized low pH Nam formulations can heighten the response in 3D skin models. Methods Homo keratinocytes treated with Nam were evaluated for autophagosome accumulation and consecration of ATG5 by gene expression, immunoblotting and immune‐fluorescence microscopy. 3D pare equivalents were topically treated with Nam formulations at pH 5.8 and 3.8. Gene expression profiling and immunoblot analysis of ATG5 were performed. Results Nam treatment of keratinocytes led to an accumulation of autophagosomes with a maximal point at 48 h. Gene expression of ATG5 was induced by Nam, and immunoblots stained for ATG5 showed a meaning increment afterwards six h of handling. Gene expression profiling of 3D epidermal skin equivalents treated with Nam at pH 3.8 showed stronger consecration of autophagy‐related genes, including ATG5, compared with pH 5.8 formulas. Enrichment for cistron ontology terms on autophagy showed an increased linkage with Nam formulas at pH iii.8. Conclusions We plant that Nam induces autophagosome accumulation and ATG5 levels in keratinocytes. Nosotros likewise discovered that a Nam formulation at pH 3.8 can farther increase levels of ATG5 in 3D peel models when compared to Nam at pH 5.8. These data support that Nam can induce autophagy in keratinocytes and formulations at pH iii.8 tin can raise the impact. We hypothesize that optimized formulations at pH 3.8 tin can meliorate skin ageing appearance via autophagy induction.

... Niacinamide is the physiologically active analog of Vitamin B3, which inhibits the transfer of melanosomes to the surrounding keratinocytes and besides to disrupt the prison cell-signaling pathway between melanocytes and keratinocytes equally suggested by diverse in vitro studies. Information technology, however, does not inhibit tyrosinase action or cell proliferation to affect melanogenesis (Matts et al., 2002). ...

Hyperpigmentation of the pare refers to a dermatological condition which alters the color of the skin, making it discoloured or darkened. The treatments for hyperpigmentation disorders oft take very long to bear witness results and have poor patient compliance. The first‐line treatment for hyperpigmentation involves topical formulations of conventional agents such as hydroquinone, kojic acid, glycolic acid followed by oral formulations of therapeutic agents similar tranexamic acid, melatonin, cysteamine hydrochloride. The second‐line approaches include chemical peels and light amplification by stimulated emission of radiation therapy given nether the observation of proficient professionals. However, these therapies pose certain limitations and adverse effects similar erythema, skin peeling and drying and require long treatment elapsing to show visible furnishings. These shortcomings of the conventional treatments provided scope for further research on newer alternatives for managing hyperpigmentation. Some of these therapies include novel formulations similar solid lipid nanocarriers, liposomes, phytochemicals, platelet‐rich plasma, microneedling. This review focuses on elaborating on several hyperpigmentation disorders and their mechanisms, the current, novel and emerging treatment options for management of hyperpigmentation.

... Pellagra symptoms include skin dermatitis, dementia, and diarrhea, all of which can be reversed with Nam supplementation. Over the past few decades, Nam has become an important molecule for usage in cosmetic and pharmaceutical products for the handling of acne, skin photoaging attributes, and skin barrier integrity improvement (Matts et al., 2002;Wohlrab & Kreft, 2014). It has been reported that Nam tin can protect cells from inflammation, oxidative stress, and metabolic disruption (Sivapirabu et al., 2009;Zhang et al., 2012) and has been found to mitigate some of the acute and chronic dissentious effects of UV exposure on pare (Snaidr et al., 2019). ...

Alterations in metabolism in peel are accelerated by environmental stressors such every bit solar radiation, leading to premature aging. The impact of aging on mitochondria is of involvement given their disquisitional role for metabolic output and the finding that environmental stressors cause lowered free energy output, particularly in fibroblasts where damage accumulates. To better understand these metabolic changes with aging, we performed an in-depth profiling of the expression patterns of dermal genes in face, forearm, and buttock biopsies from females of xx-seventy years of age that encode for all subunits comprising complexes I-V of the mitochondrial electron send chain. This complements previous preliminary analyses of these changes. "Oxidative phosphorylation" was the top canonical pathway associated with aging in the confront, and genes encoding for numerous subunits had decreased expression patterns with age. Investigations on fibroblasts from older aged donors likewise showed decreased factor expression of numerous subunits from complexes I-V, oxidative phosphorylation rates, spare respiratory capacity, and mitochondrial number and membrane potential compared to younger cells. Treatment of older fibroblasts with nicotinamide (Nam) restored these measures to younger cell levels. Nam increased complexes I, 4, and 5 action and gene expression of representative subunits. Elevated mt-Keima staining suggests a possible machinery of activity for these restorative furnishings via mitophagy. Nam likewise improved mitochondrial number and membrane potential in younger fibroblasts. These findings evidence there are significant changes in mitochondrial functionality with aging and that Nam handling can restore bioenergetic efficiency and capacity in older fibroblasts with an amplifying result in younger cells.

... The key active in the skin care products is niacinamide. This material is known to be effective in improving skin texture, elasticity, fine lines and wrinkles, red blotchiness, hyperpigmentation, lord's day damage and sallowness seen with ageing [17,18]. Although objective information are not presented in this manuscript, our own data in the study conducted in Prc and described below showed meaning improvement in pare hydration, pare barrier function, and skin elasticity after 8 days of product use. ...

  • Lixia Zhang
  • Aldhel Adique
  • Pradipta Sarkar
  • Miranda A Farage Miranda A Farage

Importance: Consumers purchase a wide variety of consumer products and come into contact with these products on a daily ground. Manufacturers invest securely in developing new products or improving existing products, in gild to produce a positive impact on the lives of consumers. Objective: The goal of this study was to determine the impact of over-the-counter pare intendance products on the quality of life (QoL) of female person consumers. Design and Measures: A QoL instrument developed for consumer products (the Farage QoL with an added Peel Care Module) was used to assess the impact of a 28-twenty-four hours facial skin care regimen using commercially bachelor products formulated to better elasticity, firmness and hydration, and to correct age- and sun-related peel colour. Responses were nerveless prior to study commencement, at completion of the production usage stage, and afterwards a period of withdrawal of the production with reversion to a bones skin care regimen. Participants: Two master study groups from Australia included 89 new mothers, i.e., women with children two years and nether (mean historic period ± SD was 34 ± 4.viii), and a national representative sample of 91 women (45 ± 12). An additional test grouping from China consisted of 40 younger cosmetic users (25 ± 4.iii). The Skin Care Module was not included in the instrument for the tertiary grouping. Results: Later on 28-days of usage, both examination groups in the main report showed pregnant comeback in three of v items in the Skin Care Module (improved feelings of empowerment, happiness and self-esteem). Improvements persisted after two weeks of product withdrawal. In the main QoL instrument, the New Mothers group showed significant improvement in the Well-Being domain, driven by improvements in the Cocky-Image and Self Competence subdomains. The National Representative group showed improvements in the Energy and Vitality domain, driven past improvements in the Personal Pleasure, Concrete State and Routine Activeness subdomains. The additional group in the China study showed results similar to the New Mothers grouping. Conclusions and Relevance: A quality and efficacious skin care regimen can have a positive impact on the QoL of consumers. Differences in responses of the test groups were likely related to differences in the mean age and differences in time available to wait after themselves.

... Nicotinamide (Nam; aka niacinamide, vitamin B3) has been used for decades in cosmetic and pharmaceutical products for the treatment of acne, pare photoaging attributes, and barrier integrity comeback [12][13][14]. It has been reported that Nam tin protect cells from oxidative stress, UVinduced immunosuppression, and metabolic disruption [15][sixteen][17]. ...

  • J.C. Bierman
  • Timothy Laughlin
  • Makio Tamura
  • John Oblong John Oblong

Daily exposure of skin to environmental stressors leads to molecular and morphological changes ascribed as premature aging. These stressors include solar radiations, industrial pollution, fossil fuel and carbon emissions, which crusade cellular damage that induces an inflammatory response in skin. Several inflammatory components are known to exist involved in triggering the senescence-associated secretory phenotype (SASP) which is known to advance aging. It is hypothesized that preventing induction of inflammation by ecology stressors can prevent premature aging. Since information technology is known that nicotinamide (Nam) has anti-inflammatory properties, nosotros tested whether Nam tin inhibit environmental stressor-induced inflammation. Exposure of keratinocytes to UVB, urban dust, diesel exhaust, and cigarette smoke extract stimulated production of the inflammatory mediators PGE2, IL-half-dozen, and IL-viii and induced gene expression patterns associated with apoptosis, DNA repair, and jail cell cycle control. In all cases, Nam handling significantly inhibited these stress-induced responses. Nam also reduced IL-viii levels stimulated by the combination of topically practical particulate matter (PM2.5) and UV exposure in 3D peel equivalents. Under 5% 02 conditions that more closely mimic physiological 02 levels, Nam had a heightened inhibitory upshot on UVB-induced PGE2 levels in keratinocytes. In a UV-challenge study, handling with Nam reduced skin surface IL-1RA/IL-1 inflammatory biomarkers and erythema that were induced past solar simulated radiations. These findings provide a torso of show that Nam can mitigate in part the skin'southward inflammatory response elicited by exposure to ecology stressors. This supports the potential that Nam can inhibit premature crumbling and help maintain skin's functionality and appearance.

  • J.C. Bierman
  • Timothy Laughlin
  • Makio Tamura
  • John Oblong John Oblong

Objective To evaluate whether niacinamide (Nam) tin can mitigate product of inflammatory and senescence‐related biomarkers induced by ecology stressors. Methods Human epidermal keratinocytes were exposed to UVB, urban dust, diesel exhaust, and cigarette smoke extract and treated with Nam or vehicle control. Total thickness 3‐D skin organotypic models were exposed to a combination of UVB and PM2.5 and treated with Nam or vehicle control. Quantitation of the SASP‐related inflammatory mediators PGE2, IL‐6, and IL‐8 was performed on cultured media. UVB‐exposed keratinocytes treated with and without Nam were immunostained for the senescence biomarker Lamin B1 (LmnB1). Transcriptomics profiling of cigarette fume extract effects on keratinocytes was performed. A placebo controlled double blinded clinical was conducted on 40 female panelists that were pretreated on back sites for two weeks with 5% Nam or vehicle and then exposed to 1.5 minimal erythemal dose (MED) solar simulated radiations (SSR). Treated sites were compared to non‐treated exposed sites for erythema and the peel surface IL‐1αRA/IL‐1α inflammatory biomarkers. Results UVB induced synthesis of PGE2, IL‐8 and IL‐six and reduced LmnB1 levels in keratinocytes. Urban dust and diesel fuel exhaust only stimulated synthesis of IL‐eight whereas cigarette smoke excerpt simply stimulated levels of PGE2. In all exposures, handling with Nam significantly mitigated synthesis of the inflammatory mediators and restored levels of UVB‐reduced LmnB1. In the 3D peel equivalent model, Nam reduced IL‐8 levels stimulated by a combination of topical PM2.five and UV exposure. In a UV‐claiming clinical, pretreatment with 5% Nam reduced erythema and skin surface IL‐1αRA/IL‐1α inflammatory biomarkers that were induced by SSR. Conclusion Since it is known that Nam has anti‐inflammatory backdrop, we tested whether Nam can inhibit environmental stress induced inflammation and senescence‐associated secretory phenotype (SASP) biomarkers. We show Nam can reduce PGE2, IL‐6, and IL‐eight levels induced by environmental stressors. Additionally, in vivo pretreatment with Nam can reduce UV‐induced erythema and skin surface inflammatory biomarkers. These findings add to the body of bear witness that Nam tin mitigate the skin's inflammatory response elicited by ecology stressors. This supports Nam can potentially inhibit senescence and premature aging and thereby maintain skin'south functionality and appearance.

  • Gayathri P.P
  • Vidya Viswanad

Background Atopic dermatitis(or eczema) can exist defined as a chronic inflammatory condition accompanied with severe pruritus. Objective The prepared gel was evaluated for in-vitro drug release, in vitro occlusion studies, transepidermal water loss studies, peel permeation studies, in-vitro skin irritation studies and anti-inflammatory cell line studies. Methods In vitro drug release studies were performed using Franz diffusion cells.The in vitro occlusion studies were carried out past the procedure reported by Wissing et al. TEWL determination was washed by the method proposed by Reiger. The pare permeation studies were carried out using porcine pare using Franz improvidence cells. In-vitro peel irritation written report were carried out using HET-CAM (Hen's Egg Test on the Chorioallantoic Membrane) method. Anti-inflammatory cell line studies were carried out using RAW 264.7 cell lines. Results In-vitro drug release studies,drug release of nicotinamide from nanoemulsion gel was found to exist more than marketed gel. Kinetic modelling showed a higuchi model with non- fickian diffusion. In vitro occlusion written report showed the percentage of evaporated water from prepared nanoemulsion formulation later 72 hours is very less compared with the other formulations. The TEWL measurement shows the reduction in TEWL has more in prepared nanoemulsion gel than other formulations.Anti-inflammatory cell line studies proved that the nanoemulsion gel have inhibition capacity on COX activeness,LOX activity, Inducibe nitric oxide synthase and cellular nitrate levels. Conclusion Dha oil based nicotinamidenanoemulsion gel were prepared successfully and the evaluation of prepared gel showed better drug release and skin permeation with better anti-inflammatory activity.

  • John Oblong John Oblong
  • Andrew West. Peplow
  • Scott Thousand. Hartman
  • Michael G. Davis

This alphabetic character is intended to clarify misconceptions in the consumer earth on the alleged side furnishings of niacinamide (Nam) on hair growth properties. It is important that the overall body of prove related to Nam and hair biology exist reviewed so as not to confuse consumers and patients on Nam touch on facial and body pilus. We have reviewed the published literature and provide new data to demonstrate that Nam has a neutral, if any, bear upon on pilus growth backdrop.

  • Thomas Franz Thomas Franz

The use of in vitro preparations of man skin to study percutaneous absorption is widespread. Yet, up to the present time, footling has been done to systematically validate this model and demonstrate the extent to which it mimicks in vivo assimilation. In this study, the permeability of 12 organic compounds has been evaluated in excised peel and the results compared to those obtained previously by others in living man. With special emphasis being given here to duplicating in vivo atmospheric condition, information technology was possible to demonstrate an splendid qualitative agreement betwixt the two methods. In all cases, the absorption pattern determined in vitro rather precisely paralleled the pattern which was obtained in vivo. Quantitative understanding between the two sets of data was less than perfect, although the in vitro method adequately distinguished compounds of low permeability from those of high permeability and ranked and then in approximately the aforementioned social club found in vivo. This systematic comparison of in vitro with in vivo information was clearly shown how accurately in vitro absorption studies can reverberate the living state.

  • Barbara Gilchrest Barbara Gilchrest
  • M Yaar

It is now well established that ageing occurs at the level of private cells in the peel and other organ systems. Changes in jail cell behaviour, protein production and gene expression in response to standardized stimuli are readily observed in cultured cells derived from young vs old donors and from photoaged vs lord's day-protected torso sites. Whether these changes are best viewed equally a cause or a consequence of ageing cannot be adamant at present. Still, available data at present provide cellular and molecular correlates for the well-known differences in clinical responsiveness between newborn, adult and photoaged peel. From this basis, it will hopefully exist possible to develop a more comprehensive agreement of cutaneous ageing processes.

  • HK Seitz
  • Yin Xu
  • U A Simanowski
  • Brigitte Osswald Brigitte Osswald

It has been reported that crumbling strikingly decreases in vivo ethanol metabolism in F344 rats without major effects on hepatic alcohol dehydrogenase (ADH) activity. Because hepatic ADH activity is non ever rate limiting in the oxidation of ethanol, we measured in vivo ethanol emptying rate (EER), hepatic ADH activity, and the hepatic-cytoplasmic and mitochondrial redox states after acute ethanol application in 2- and 12-month-old F344 rats of both sexes. In male person, simply non in female, animals EER decreased with age significantly, by 28% (P less than 0.01). The trunk-to-liver weight ratio was significantly increased in male (39.4 +/- 1.5 vs 46.5 +/- 2.0; P less than 0.05), only non in female, animals with age. Specific action of ADH was not significantly changed past age, while the activity was significantly reduced with age in male person, simply not female, rats when related to body weight (5.1 +/- 0.four vs 3.9 +/- 0.iii mumoles/100 g b.wt./min; P less than 0.05). The cytoplasmic, but not the mitochondrial (NAD+) to (NADH), ratio was significantly decreased with age in male livers (317 +/- 48 vs 793 +/- 128, P less than 0.05), while this was not the instance in female livers. In summary, the information testify a sexual practice dependence of the event of age on ethanol metabolism. The observed reduction in in vivo EER with age in male animals is due at least in part to an increased trunk-to-liver weight ratio, decreased hepatic ADH activeness, and reduced availability of NAD+, the cofactor of the ADH reaction. The cause of this may be decreased transport of reducing equivalents through the mitochondrial membrane due to a lack of shuttle systems or a change in the physicochemical properties of the mitochondrial membrane, or decreased reutilization of NADH equally NADPH resulting from a reduction of microsomal ethanol oxidation with age.

  • Genji Imokawa
  • Akihito Abe
  • Kumi Jin
  • Akira Hidano

Stratum corneum lipids are an important determinant for both water-retentivity function and permeability-barrier function in the stratum corneum. However, their major constituent, ceramides, accept not been analyzed in detail in peel diseases such as atopic dermatitis that evidence defective water-memory and permeability-barrier function. In an attempt to assess the quantity of ceramides per unit mass of the stratum corneum in atopic dermatitis, stratum corneum sheet was removed from the forearm pare by stripping with cyanoacrylate resin and placed in hexane/ethanol extraction to yield stratum corneum lipids. The stratum corneum was dispersed by solubilization of cyanoacrylate resin with dimethylformamide, and afterwards membrane filtration, the weight of the stratum corneum mass was measured. The ceramides were quantified past sparse-layer chromatography and evaluated as microgram/mg stratum corneum. In the forearm skin of healthy individuals (northward = 65), the total ceramide content significantly declined with increasing age. In atopic dermatitis (northward = 32-35), there was a marked reduction in the corporeality of ceramides in the lesional forearm pare compared with those of healthy individuals of the aforementioned age. Interestingly, the non-lesional skin likewise exhibited a like and significant decrease of ceramides. Amongst half dozen ceramide fractions, ceramide 1 was virtually significantly reduced in both lesional and non-lesional skin. These findings propose that an insufficiency of ceramides in the stratum corneum is an etiologic factor in atopic dry skin.

  • J F Jongkind
  • Anton Verkerk
  • Martin Poot Martin Poot

In cultured human peel fibroblasts the glucose flux through the hexose monophosphate shunt (HMS) amounts to four% of the glucose flux through the glycolytic pathway. Upon in vitro ageing the rate of glucose utilization through the HMS is decreased more than than 50%. This decrease in HMS was non caused by a limiting enzymatic capacity since glucose utilization through the HMS could be raised at least thirty-fold in both 'young' and 'aged' fibroblasts upon stimulation with phenazine methosulphate. This effect of in vitro ageing upon glucose metabolism was also not due to differences in proliferation charge per unit betwixt 'young' and 'anile' human fibroblasts, since at that place was no difference in glucose utilization between proliferating and growth-inhibited (confluently cultured) fibroblasts. The NADPH/NADP ratio was found to exist decreased by 12% in 'aged' cells.

  • Alan R. Shalita
  • J. Graham Smith
  • Lawrence Charles Parish Lawrence Charles Parish
  • Dan Thou. Chalker

Systemic and topical antimicrobials are effective in the treatment of inflammatory acne vulgaris; however, widespread utilize of these agents is becoming increasingly associated with the emergence of resistant pathogens raising concerns almost microorganism resistance and highlighting the demand for alternative nonantimicrobial agents for the treatment of acne. Nicotinamide gel provides strong antiinflammatory activity without the hazard of inducing bacterial resistance. In our double-blind investigation, the safety and efficacy of topically applied 4% nicotinamide gel was compared to 1% clindamycin gel for the handling of moderate inflammatory acne vulgaris. Seventy-six patients were randomly assigned to apply either 4% nicotinamide gel (n = 38) or 1% clindamycin gel (northward = 38) twice daily for viii weeks. Efficacy was evaluated at 4 and viii weeks using a Md'south Global Evaluation, Acne Lesion Counts, and an Acne Severity Rating. After 8 weeks, both treatments produced comparable (P = 0.19) beneficial results in the Doctor's Global Evaluation of Inflammatory Acne; 82% of the patients treated with nicotinamide gel and 68% treated with clindamycin gel were improved. Both treatments produced statistically similar reductions in acne lesions (papules/pustules; -60%, nicotinamide vs. -43%, clindamycin, P = 0.168), and acne severity (-52% nicotinamide group vs. -38% clindamycin group, P = 0.161). These data demonstrate that four% nicotinamide gel is of comparable efficacy to 1% clindamycin gel in the handling of acne vulgaris. Because topical clindamycin, like other antimicrobials, is associated with emergence of resistant microorganisms, nicotinamide gel is a desirable culling treatment for acne vulgaris.

  • Helen L. Gensler

Ultraviolet (UV) B irradiation leads to a stiff immunosuppression of the chapters to reject syngeneic, antigenic tumors. If this immunosuppression is critical for the development of about peel tumors, then its prevention should effect in prevention of photocarcinogenesis. We previously showed a correlation between the inhibition of photoimmunosuppression and prevention of photocarcinogenesis past dl-alpha-tocopherol, tannic acid, or alpha-difluoromethylornithine. The current study was designed to decide whether topical nicotinamide, the agile form of vitamin B-three, or niacin, prevents immunosuppression and skin cancer in UV-irradiated mice. In a passive transfer assay for immunosuppression, splenocytes from UV-irradiated mice enhanced the growth of antigenic tumor challenges in recipient mice. Treatment of the UV-irradiated mice with 40 mumol of nicotinamide twice weekly starting 2 weeks before UV irradiation and throughout the experiment prevented this immunosuppression. UVB irradiation consisted of five weekly 30-infinitesimal exposures to banks of vi FS40 Westinghouse fluorescent sunlamps. Mice received approximately 6.ii 10 10(v) J/m2 in the passive transfer assays and 1.09 10 x(6) J/m2 in the photocarcinogenesis studies. Application of nicotinamide to UV-irradiated mice reduced skin tumor incidence from 75% to 42.5% (p = 0.016, Cox proportional hazards analysis). Thus topical nicotinamide prevented the immunosuppression and skin tumor consecration by UVB irradiation.

  • Kumaravel Rajakumar

Pellagra was in existence for nearly two centuries in Europe earlier being recognized in the U.s., where information technology was first reported in 1902. Over the next ii decades, pellagra occurred in epidemic proportions in the American South. Poverty and consumption of corn were the most frequently observed risk factors. Since the exact cause and cure of pellagra was not known, a culture of "pellagraphobia" formed among the public. Patients were shunned and ostracized. The medical community implicated spoiled corn as the cause of pellagra, which had economical repercussions for agriculturists. Joseph Goldberger, Doc, of the Usa Public Wellness Service somewhen solved the secret of the malady: faulty diet. Goldberger was able to prevent and induce pellagra by dietary modification, a landmark effect in the annals of medicine, nutrition, and epidemiology. His work and the social history of that period are reviewed.

  • Osamu Tanno
  • Yukiko Ota
  • North Kitamura
  • Shintaro Inoue Shintaro Inoue

Stratum corneum lipids, peculiarly ceramides, are important components of the epidermal permeability barrier that are decreased in atopic dermatitis and aged skin. We investigated the effects of nicotinamide, 1 of the B vitamins, on biosynthesis of sphingolipids, including ceramides and other stratum corneum lipids, in cultured normal human being keratinocytes, and on the epidermal permeability barrier in vivo. The rate of sphingolipid biosynthesis was measured by the incorporation of [14C]-serine into sphingolipids. When the cells were incubated with 1-30 micromol 50-one nicotinamide for 6 days, the rate of ceramide biosynthesis was increased dose-dependently past 4.1-v. 5-fold on the sixth day compared with control. Nicotinamide likewise increased the synthesis of glucosylceramide (vii.4-fold) and sphingomyelin (iii.1-fold) in the same concentration range effective for ceramide synthesis. Furthermore, the activity of serine palmitoyltransferase (SPT), the rate-limiting enzyme in sphingolipid synthesis, was increased in nicotinamide-treated cells. Nicotinamide increased the levels of human LCB1 and LCB2 mRNA, both of which encode subunits of SPT. This suggested that the increment in SPT activity was due to an increase in SPT mRNA. Nicotinamide increased not simply ceramide synthesis merely also free fatty acrid (2.3-fold) and cholesterol synthesis (ane.five-fold). Topical application of nicotinamide increased ceramide and free fat acrid levels in the stratum corneum, and decreased transepidermal water loss in dry skin. Nicotinamide improved the permeability barrier by stimulating de novo synthesis of ceramides, with upregulation of SPT and other intercellular lipids.