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Review on Skin Whitening Agents

  • Faculty of Pharmacy, Northern Border University


Skin whitening is a term used for lightening the complexion of the skin through artificial means like creams, lotions, soaps and injections. Unfortunately the appeal of these skin bleaching products is based on the obsession of people across the world with skin color. Melanins are produced by specialized cells, termed melanocytes, which are located primarily in the skin, hair bulbs, and eyes. The melanins can be of two basic types: eumelanins, which are brown or black, and phaeomelanins, which are red or yellow, in mammals typ-ically there are mixtures of both types (Figure1). Increased produc-tion and accumulation of mela-nins characterize number of skin diseases, which include hyperpi-gentation such as melanoma, post-inflammatory melanoderma, solar lentigo, etc. Several modalities of treatment for these problems are available including chemical agents or physical therapies. The aim of this review article is to show that some of the skin whitening creams , often sold illegally without a prescription may contain dangerous ingredients that could put people health at risk.
Khartoum Pharmacy Journal Vol. 13 No. 1 June. 2010
Review on Skin Whitening Agents
Skin whitening is a term used
for lightening the complexion of
the skin through articial means
like creams, lotions, soaps and in-
jections. Unfortunately the appeal
of these skin bleaching products is
based on the obsession of people
across the world with skin color.
Melanins are produced by special-
ized cells, termed melanocytes,
which are located primarily in the
skin, hair bulbs, and eyes. The
melanins can be of two basic types:
eumelanins, which are brown or
black, and phaeomelanins, which
are red or yellow, in mammals typ-
ically there are mixtures of both
types (Figure1). Increased produc-
tion and accumulation of mela-
nins characterize number of skin
diseases, which include hyperpi-
gentation such as melanoma, post-
inammatory melanoderma, solar
lentigo, etc. Several modalities of
treatment for these problems are
available including
chemical agents or
physical therapies.
The aim of this
review article is to
show that some of
the skin whitening
creams , often sold
illegally without a
prescription may
contain danger-
ous ingredients that
could put people
health at risk.
Keywords: skin whitening;
melanin; mercury; hydroquinone;
The term skin whitening (also
called skin bleaching) covers a
variety of cosmetic methods used
in an attempt to whiten the skin
(Wikipedia, 2007).
Visible pigmentation in mam-
mals results from the synthesis and
distribution of melanin in the skin,
hair bulbs, and eyes. The melanins
can be of two basic types: eumela-
nins, which are brown or black, and
phaeomelanins, which are red or
yellow, in mammals typically there
are mixtures of both types. Mela-
nins are produced by specialized
cells, termed melanocytes, which
are located primarily in the skin,
hair bulbs, and eyes. Melanocytes
synthesize melanin within discrete
organelles, termed melanosomes,
which can be produced in varying
sizes, numbers, and densities. The
melanosomes are then passed on,
in skin to keratinocytes and in hair
bulbs to the hair shaft, where the
nal distribution patterns of the
pigment are determined. This dis-
tribution plays an important role in
determining color; note for exam-
ple the variety of colors in the skin,
hair, and eyes of humans (Hearing
and Tsukamoto, 1991)
The most essential enzyme in
this melanin biosynthetic pathway
is tyrosinase and it is the only en-
zyme absolutely required for mela-
nin production. The main physi-
ological stimulus of melanogenesis
is the UV radiation of solar light,
which can act directly on melano-
cytes or indirectly through the re-
lease of keratinocyte-derived fac-
tors such as α-melanocyte stimu-
lating hormone (MSH). Increased
production and accumulation of
melanins characterize number of
skin diseases, which include hyper-
pigmentation such as melanoma,
post-inammatory melanoderma,
solar lentigo, etc. Several modali-
ties of treatment for these problems
are available including chemical
agents or physical therapies (Kang
et al., 2004; Pravez et al., 2007).
Stretch marks
Ahmed Hassan H. Arbab (M.Pharm) & Mahmoud Mudawi Eltahir (PhD)
Faculty of Pharmacy, Omdurman Islamic University
The classication of
depigmenting activity
and skin whitening
Depigmentation can be
achieved by (i) regulating the
transcription and activity of tyro-
sinase, (ii) regulating the uptake
and distribution of melanosomes
in recipient keratinocytes and (iii)
interference with melanosomes
maturation and transfer ( Solano et
al., 2006). However, as a result of
the key role played by tyrosinase
in the melanin biosynthesis, most
whitening agents acts specially
to reduce the function of enzyme
by mean of several mechanisms
(Donsing and Viyoch, 2008).
Therefore, tyrosinase inhibitors
have become increasingly impor-
tant in the cosmetic and medicinal
products used in the prevention of
hyperpigmentaion and skin whit-
ening (Khan, 2007).
Skin whiteners in
commercial use
1- Mercury containing
In the early days, toxic com-
pounds, such as mercury containing
compounds have been used for skin
whitening purposes because mercu-
ry inactivates the enzyme that leads
It may also function by interfering
with the formation or degradation
of melanosomes and by inhibiting
the synthesis of DNA and RNA
within melanocytes.
Hydroquinone is a most widely
used depigmenting agent at pres-
ent, but is considered to be highly
cytotoxic to melanocytes and po-
tentiality mutagenic to mammalian
cells (Thiele et al., 1997; Dons-
ing and Viyoch, 2008). It can be
irritating and causes redness and
burning, also it has been shown
to cause exogenous ochronosis.
Ochronosis may result in loss of
elasticity of the skin and impaired
wound healing which has resulted
in a ban on its over-the-counter use
in USA and many other countries.
It was only ever allowed for small
areas of skin and for treating things
like age spots or sun spots (Gabri-
el, 2008).
3- Corticosteroids:
Topical corticosteroids whiten
the skin by initial blanching due
to vasoconstriction, slowing down
skin cell turnover so reducing the
number and activity of melano-
cytes and reducing production of
melanocyte stimulating hormone
(Oakley, 2010), but their absorp-
tion through the skin can cause ad-
renal suppression and even Cush-
ing’s syndrome depending on the
area of the body being treated and
the duration of treatment. Local
to the production
of melanin. Long
term application of
mercurial products
to the skin makes
the skin and nails
darker, because the
mercury is depos-
ited in the epidermis and hair fol-
licles (Oakley, 2010).
Mercury poisoning results in
acute and chronic toxicity includ-
ing neurological and kidney dam-
age, as well as acrodynia, which is
characterised by pink discoloration
of the hands and feet, irritabil-
ity, photophobia and polyneuritis
(Oakley, 2010). These toxic com-
pounds have been banned in the
majority parts of the world, and are
no longer used in cosmetic prod-
ucts for this purpose. It should be
mentioned that there are still some
illegal uses of mercury containing
products in developing countries.
2- Hydroquinone:
Its bleaching properties were
discovered when it was observed
that colored tanners wearing rub-
ber gloves acquired discolored
areas on hands and forehands.
The studies on the cause of this ef-
fect pointed out to hydroquinone,
an agent used in rubber synthesis
(Parvez, 2007). Hydroquinone is
a hydroxyphenolic compound that
inhibits the synthesis of melanin
by inhibiting tyrosinase enzyme.
Tyrosine Dopa Dopaquinone
Figure1 : Production of melanin
Khartoum Pharmacy Journal Vol. 13 No. 1 June. 2010
side-effects of topical corticoster-
oids include spread and worsening
of untreated infection; irreversible
thinning of the skin, contact der-
matitis, perioral dermatitis, acne,
or worsening of acne or acne rosa-
cea and hypertrichosis also report-
ed (British Medical Association
and Royal Pharmaceutical Society,
4- Ascorbic acid (Vitamin C):
Ascorbic acid and its deriva-
tives are used as an antioxidant
because its capacity to reduce
back o-dopaquinone to dopa, thus
avoiding melanin formation, also
it have a protective effect against
skin damage induced by UV- ir-
radiation (Policarpio and Lue,
2009). However, ascorbic acid has
other adverse affects as it can in-
duce a large increase of free radi-
cals with traces of metal ions. To
improve its stability, skin absorp-
tion and hypopigmenting effect,
some ascorbate esters, such as the
magnesium ascorbyl-2-phosphate
(MAP), has been synthesized.
Daily application of a cream con-
taining 10% of this ascorbic acid
derivative has been found to pro-
duce a signicant whitening effect
in patients with melasma. Ascorbic
acid has been demonstrated as an
effective depigmenting strategy in
a randomized, double-blind, place-
bo-controlled trial (Solano et al.,
5- Tretinoin:
Tretinoin is the main topical
retinoid that has been used in skin
whitening products. The mecha-
nisms for reducing pigmentation
include inhibition of tyrosinase
induction, interference with pig-
ment transfer, and acceleration
of epidermal turnover. They also
have the ability to disperse pig-
ment granules within keratino-
cytes. Retinoids may act as pen-
etration enhancers when used
with other whitening agents like
hydroquinone and mequinol. The
most common adverse effects in-
clude burning, stinging, erythema,
dryness, and scaling. Although
the adverse effects are reversible,
retinoid dermatitis may itself lead
to hyperpigmentation, especially
in dark-skinned individuals (Poli-
carpio and Lue, 2009). It is a pre-
scription medication because of
potential risk in pregnancy. It can
be quite irritating and may cause
contact irritant dermatitis (Oakley,
2010). Tretinoin is useful for treat-
ing inammatory lesions in mild
to moderate acne (British Medical
Association and Royal Pharma-
ceutical Society, 2007).
6- Azelaic acid:
Azelaic acid is a naturally oc-
curring straight chain, saturated di-
carboxylic acid which is produced
by yeast, Pityrosporum ovale. Aze-
laic acid is a rather weak competi-
tive inhibitor of tyrosinase. In addi-
tion, it has an antiproliferative and
cytotoxic effect on melanocytes
(Pravez et al., 2007). Although
azelaic acid was initially pre-
scribed for the treatment of acne,
it has been successfully used in the
treatment of lentigines, rosacea,
melasma and post inammatory
hyperpigmentation (Policarpio and
Lue, 2009). Azelaic acid is not
able to induce depigmentation on
normally pigmented skin, suggest-
ing its selective antiproliferative
and cytotoxic action on abnormal
melanocytes. It has been reported
to be effective in hypermelanosis
caused by physical and chemical
agents, as well as other skin dis-
orders characterized by abnormal
proliferation of melanocytes. The
only problem of treatment with
azelaic acid is that its therapeutic
response is rather slow (Solano et
al., 2006)
7- Laser treatments:
Both ablative and nonablative
lasers can have a profound effect on
melasma. Lasers function by emit-
ting a monochromic, high-intensity
energy source that is absorbed by
melanin in the skin,. The absorp-
Table: Comparison between skin whitening agents
Mechanisms of
Advantage Disadvantage Recommendations
Mercury Inactivate
tyrosinase enzyme
Acute and chronic
toxicity, neurological and
kidney damage, acrodynia,
irritability, photophobia ,
Should not be used
Hydroquinone -Inhibits tyrosinase
- Cytotoxic to
Stable in combinations Cytotoxic, mutagenic
Ochronosis, contact
dermatitis,skin irrtation,
redness & burning
Only allowed for small
areas of skin under
medical supervision
- reducing the
number and activity
of melanocytes
production of MSH
Useful for inammatory
conditions of the skin
like eczema, contact
dermatitis, and scabies
Spread and worsening
of untreated infections,
contact dermatitis, acne
rosacea, hypertrichosis,
adrenal suppression
Not recommended for
skin whitening
Ascorbic acid
(vitamin C)
- Reduce back
o-dopaquinone to
Have a protective
effect against skin
damage induced by UV-
Highly unstable, low
penetration, weak
MAP is more effective
and safe derivative
Tretinoin -Inhibits tyrosinase
- interferes with
melanin transfer
useful for treating
inammatory lesions in
mild to moderate acne
Quite irritating and may
cause contact irritant
Should not be used
without prescription
Azelaic acid Weak inhibitor
of tyrosinase,
cytotoxic effect on
Usefulfor lentigines,
rosacea, and post
Therapeutic response is
rather slow
Should be used under
medical supervision
Laser Emit a high-
intensity energy
source that destroy
melanin in the skin
Discomfort, redness,
mild swelling, and
Not considered a rst-
line treatment
tion of energy destroys the melanin.
However, the results are not always
consistent, and problems have been
reported. Adverse effects from la-
ser treatment include discomfort,
redness, mild swelling, and post
inammatory hyperpigmentation.
Thus is not considered a rst-line
treatment because of the adverse
effects of hyperpigmentation (Poli-
carpio and Lue, 2009). Laser treat-
ments are more likely to result in
problems for those with darker skin
tones (Wikipedia, 2007).
8- Fruits:
Many fruits have skin whiten-
ing effect when they are eaten or
scrubbed on skin. The leading fruit
is papaya, wherein its enzyme pa-
pain can whiten the skin. Other no-
table fruits are lemon, lime, calam-
ondin, and orange; all of these have
Vitamin C which is said to have a
skin whitening effect (Wikipedia,
The danger of using
skin whitening agents
without prescription
Skin whitening creams - often
sold illegally without a prescrip-
tion - may contain dangerous in-
gredients that could put your health
at risk. Dermatologists say they are
Khartoum Pharmacy Journal Vol. 13 No. 1 June. 2010
seeing more and more women of
Hispanic and African descent suf-
fering from complications related
to the use of skin whitening creams
(Parker et al., 2010).
Side effects of skin whitening
Dermatitis with severe •
drying, cracking of the skin
and itching
Melasma and •
hyperpigmentation of the
Mercury poisoning•
Fetal toxicity in pregnant •
Cushing’s syndrome•
Liver failure•
Skin cancer•
The hypopigmentation (lack
of skin pigment) leaves the skin
prone to UV damage by sunlight.
This can predispose to skin can-
cers like a melanoma. (Health i
Talk, 2010).
Treatment of skin damaged
by skin whiteners
The hyperpigmentation caused
by skin whitening agents is not
‘curable’ and will persist for a
lifetime. Using a sunscreen on a
daily basis will assist in reducing
the damage caused by sun expo-
sure. Emollients are useful for dry
and cracking skin and in cases of
severe itching; a mild hydrocorti-
sone cream may be used for a short
period. Always consult a derma-
tologist for medical attention when
treating skin damaged by long
British Medical Association (BMA)
and Royal Pharmaceutical Society (RPS)
54, British National Formulary (BNF)
54, BMJ Publishing Group Ltd and RPS,
September (2007).
Donsing,P., and Viyoch,J., Thai
Breadfruitûs Heartwood Extract: A New
Approach to Skin Whitening., SWU Sci. J.
2008; 24 (1): 9-23.
Gabriel, J., Hydroquinone:
Cancer-Causing Skin Bleach, http://, (2008).
Hearing,V.J., and Tsukamoto, K.,
Enzymatic control of pigmentation in
mammals. The FASEB Journal. 1991; 5:
Health i Talk, http://www.healthitalk.
lightening-bleaching-cream (Accessed:
Kang, H.S., Kim, H. R., Byun , D.S., Son,
B.W., Nam , T. J. and Chio, J.S., Tyrosinase
Inhibitors Isolated from the Edible Brown
AlgaEcklonia stolonifera. Arch Pharm
Res. 2004; 27(12): 1226-1232.
Khan, H. T. M. Molecular design of
tyrosinase inhibitors: A critical review of
promising novel inhibitors from synthetic
origins. Pure Appl. Chem. 2007; 79 (12):
Oakley, A., Bleaching creams, New
Zealand Dermatological Society
treatments/bleach.html Last updated 24
/2/2010 (Accessed: 12/05/2010).
Parker Waichman Alonso LLP, Beware
of Skin Lightening Creams. http://www., Jan
18, 2010.
Policarpio, B., Lui, H., Skin Lightening
and Depigmenting Agent. e medicine,
article/1068091-overview. Last updated:
term use of skin bleaches. (Health
i Talk, 2010).
The use of skin whitening •
agents must be controlled.
In Sudan, the skin whitening •
agents sold in unlicensed
places and might be affected
by the high temperature;
therefore the regulatory
authority must increase the
efforts to protect the people
from the side effects of these
Different methods must •
be used to increase the
awareness of the people
about the use and danger of
the whitening agents.
Research should be •
conducted to study the
effect of temperature on
the stability and use of the
whitening agents.
26.10. 2009 (Accessed: 12/05/2010).
Pravez, S., Kang, M., Chung, H. S. and
Bae, H., Naturally Occurring Tyrosinase
Inhibitors: Mechanism and Applications
in Skin Health, Cosmetics and Agriculture
Industries. Phytother. Res. 2007; 21:
Solano,F., Bringati,S., Picardo,M., and
Ghanem,G., Hypopigmenting agents: an
updated review on biological, chemical
and clinical aspects. Pigment Cell Res.
2007; 19: 550–571.
Thiele,J.J M. G. Traber, T. G. Polefka,
C. E. Cross and L. P.Packer, Ozone
exposure depletes vitamin E and induces
lipid peroxidation in murine stratum
cormeum. J. Invest. Dermatol. 1997;
108: 753-757.
Wikipedia, the free encyclopedia,
Skin whitening.
wiki/Skin_whitening , November 2007
(Accessed: 12/05/2010).
... 4 To inhibit the formation of melanin, the tyrosinase enzyme becomes one of the targets of whitening drugs. 5 Melanin production is induced after exposure to UV radiation and plays a major role in protecting skin cells from UV radiation. However, melanin pigmentation in the epidermis can cause skin changes such as darkening of skin color and pigmentation spots. ...
... Excessive use of steroids can cause side effects of skin thinning, hypertrichosis, and hormonal disorders, while mercury is toxic, as well as kidney and nerve damage. 5 Due to the increasing circulation of various beauty products to watch out for, especially those that use chemicals that ultimately endanger the consumer, the medical world of the present era has studied again the plants that have antioxidant and antiaging effects scientifically. Some examples of plants that have been proven to be antioxidants and antiaging here are roselle flowers (Hisbiscus sabdarifa), 6 jasmine flowers (Jasminum sambac), 7 ripe sesoot (Garcinia picrorrhiza Miq.). ...
Full-text available
Aging is a natural process in human that can be characterized by the appearance of black spot on the skin due to hyperpigmentation. Aging may occur due to an excessive amount of free radicals in the body. Antioxidants possess ability to capture free radicals and inhibit tyrosinase which induces skin aging. Aloe vera has been used in traditional medicine because it contains several bioactive compounds that act as antioxidant and prevent aging process. This study aims to determine phytochemical content, antioxidant activity and tyrosinase inhibition activity of Aloe vera rind (AVRE) and gel (AVGE) extract. This research was carried out at Aretha Medika Utama-Biomolecular and Biomedical Research Center in Bandung city in September-November 2018. Phytochemical assay was determined using modified Farnsworth method. Antioxidant assay was determined using DPPH scavenging activity and antiaging assay was obtained using tyrosinase inhibition assay. AVRE contains flavonoid, phenol, steroid, and alkaloid. Meanwhile, AVGE contains steroid and alkaloid. IC50 DPPH scavenging activity of AVRE was 113.18 µg/mL followed by AVGE was 291.96 µg/mL. IC50 tyrosinase inhibition activity of AVRE was 65.04 µg/mL followed by AVGE was 111.89 µg/mL. AVRE had more active DPPH scavenging activity and tyrosinase inhibition activity than AVGE.
... Skin whiting or skin bleaching is the material used to improve the appearance of skin as well as the lighting of the skin through artificial such as creams, lotions, soaps and injections [1,2]. whiting agents contain the most popular compound like arbutin, ascorbic acid, azelaic acid, hydroquinone, and its derivatives, kojic acid, phytic acid, retinoic acid, and among others [3]. ...
Full-text available
The skin whitening as known as skin lightening or skin bleaching is the most commonly used skincare treatment that helps to achieve a lighter and healthier skin complexion by reducing the melanin concentration in the skin in the practice of using chemical products. Several chemicals are effective in skin whitening, while some of them are toxic or have problematic safety profiles. The products requiring to contain either kind of whiting agents were seen to display labeling issues. Such an elevated number of differences suggested concerns of whether such differences between stated and revealed content of whiting agents. The Analytical chemical measurements of these objects look necessary, no reliable analytical methods have been recorded to determine most of these chemicals. Just the measurement of hydroquinone and some of its ethers is treated by a method registered by the European Commission.
... Excessive use of steroids can cause skin thinning, hypertrichosis, and hormonal disorders. Meanwhile, mercury is toxic, and can damage the kidneys and nerves (Arbab and Eltahir, 2010). ...
Free radicals can cause damage to cells or tissues, autoimmune diseases, degenerative diseases, or cancer. Therefore, the body needs important substances, namely antioxidants that can help protect the body by reducing negative effect from free radicals. Rose flower (Rosa damascena) has anthocyanin pigment which belongs to flavonoid group which has a function as antioxidant or free radical scavenger. This study aims to determine antioxidant and anti-elastase potentials of rose petals and receptacles. The method used in this study was a qualitative phytochemical test to determine the compounds contained in the Rose Petal Extract (RPE) and Rose Receptacle Extract (RRE), ABTS ((2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid))-reducing assay to determine antioxidant activity, and antiaging test with anti-elastase assay. RPE and RRE contained flavonoids, phenols, tannins and alkaloids, but did not contain saponins. RPE contained triterpenoids and terpenoids, while RRE contained steroids, but did not contain terpenoids. The inhibitory concentration (IC50) values in the ABTS reducing assay were 4.46 ± 0.34 μg/mL (RPE) and 15.49 ± 0.23 μg/mL (RRE), while the results of the anti-elastase assay were 17.51 ± 1.47 μg/mL (RPE) and 58.91 ± 2.31 μg/mL (RRE). Both RPE and RRE are potent antioxidant and anti-elastase, and RPE is more active than RRE in these assays.
... This practice is motivated by a long-standing history of social divisions, including societal pressures and stigmas, leading to the demand for lighter skin tones [17,18]. Creams, lotions, soaps, and injections indicated as a treatment for hyperpigmentation disorders are exceedingly abused as self-medication to achieve a lighter skin complexion [19,20]. In many African countries, a variety of these skin lightening preparations are easily obtained over-the-counter without a medical prescription, despite this being a requirement by law [15,21]. ...
Full-text available
The indiscriminate use of non-regulated skin lighteners among African populations has raised health concerns due to the negative effects associated with skin lightener toxicity. For this reason, there is a growing interest in the cosmetic development of plants and their metabolites as alternatives to available chemical-derived skin lightening formulations. Approximately 90% of Africa’s population depends on traditional medicine, and the continent’s biodiversity holds plant material with various biological activities, thus attracting considerable research interest. This study aimed to review existing evidence and document indigenous African plant species capable of inhibiting the enzyme tyrosinase and melanogenesis for potential incorporation into skin lightening products. Literature search on melanin biosynthesis, skin lightening, and tyrosinase inhibitors resulted in the identification of 35 plant species were distributed among 31 genera and 21 families across 15 African countries and 9 South African provinces. All plants identified in this study showed competent tyrosinase and melanogenesis inhibitory capabilities. These results indicate that African plants have the potential to serve as alternatives to current chemically-derived skin lighteners.
... 13,16,17,19 These substances were known with their high potential whitening effect by interfering production of melanin. [20][21][22] Potential hazard resulted from the long term use of these substance are severe depigmentation, irritation on skin, teratogenicity, carcinogenic effects, kidney injuries and others more. 18,[23][24][25][26][27][28] Hence safety and regulation over cosmetics products are mandatory. ...
Full-text available
Prosecutes the offenders in the court in accordance to the laws and regulations enforce with the firm penalty is upmost important to assure our laws and regulations were intact. This raises our interest to fill the knowledge gap on the prosecution successful rate, and the intensity of fines imposes serve as an indicator or baseline to an evaluation of the effectiveness of enforcement activities. This is a cross-sectional retrospective study where data were collected from the Sarawak state PEB prosecution reports from 1st January 2014 to 31st December 2016. Descriptive statistics, in numbers and percentages, were used to present the prevalence of cases prosecuted by PEB and its successful rate, while Kruskal Wallis Test was used to compare the median of the fines (2014-2016). Prosecution successful rate was found to improve from 52.6% (2014) to 62.8 (2015) and further increased to 69.4% (2016) due to the high plead guilty rate. This reflected that the intensity of the penalty imposed was not sufficient. Median of the penalties for the top 3 offences (Ranging RM1000-RM3000 throughout the study period) prosecuted shown to be statistically insignificant throughout the study periods, even though we observed the increased frequency of the cases charged. This study serves as a baseline which provides valuable insights to policymakers, researchers, and other stakeholders in determining the intensity of penalty and the necessity reformulating our existing laws and regulations.
... Tretinoin (all-trans retinoic acid) is the carboxylic acid form of vitamin A (retinol) (Akhavan and Bershad, 2003). Tretinoin mechanisms of action involve the inhibition of tyrosinase induction, the dispersion of keratinocyte pigment granules, the inhibition of melanin transfer and the acceleration of epidermal turnover (Arbab and Eltahir, 2010;Zhu and Zhang, 2006) (Fig. 1). However, tretinoin application is accompanied with a skin irritation which is dose-dependent. ...
Hyperpigmentation is one of the most common skin disorder that affects both men and women of all ethnic groups, caused by several factors, such as UV exposure and skin inflammation. Topical whitening agents were found to be the best and the least aggressive therapy for treating hyperpigmentation compared to instrumental approaches. However, topical treatment faces several obstacles due to the low stability of the whitening agents. Therefore, the encapsulation of these agents was found to be crucial as it enhances their physicochemical stability and increases their concentration at the targeted site via an improved skin permeation, penetration or distribution. In this article, we review the literature aimed to enhance the stability and the targeting of skin whitening agents through their encapsulation in various nano and micro-particulate systems.
... However, the motives for using SLP could vary across different countries and cultures. Despite the increased use of SLP in Sudan [7,[17][18][19][20][21], the key motivations as to why Sudanese females use them remain unclear. Sudanese society is a compound of multi-ethnic groups and different cultures. ...
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Context: The use of skin lightening products (SLP) containing harmful chemicals is the largest recent women’s health issue in Sudan. Despite their adverse effects, the current frequency of the use of SLP among young Sudanese women (74.4%) is recognized as high. Objectives: To assess the attitude of Sudanese female college students regarding 1) the use of SLP, and 2) their knowledge of its adverse health effects. Methods: A survey study was conducted on 364 female college students who attended lectures at the University of Gezira between July and September 2015. We asked the study participants to report socio-demographic data, whether SLP can harm a user’s health, and the motives for using SLP. Results: Although the majority of females (320/359) (89.1%) reported that SLP could harm a user’s health, 320/364 (87.9%) reported favorable attitudes toward the use of SLP. The most common motives for using SLP were: to lighten dark spots and remove acne (57.1%); because white skin is more attractive than black skin (34.3%); to attract men (33.8%); to look pretty/fashionable (28.9%); because women with white skin are treated better than women with dark skin (28.2%); and to gain self-confidence (26.9%). The results of the multivariate logistic regression model indicated more favorable attitudes toward the use of SLP in those who had a family member who bleached, and in older students who were aged 20-22 years and ≥ 23 years. Conclusion: Despite the high levels of awareness of the health risks of using SLP among female Sudanese students, they continue to report favorable attitudes toward using these products.
Hair graying occurs worldwide, and it has a high impact on the self-esteem of an individual. Hair graying is a melanogenesis disorder that can be attributed to many factors, including age, oxidative stress, psychological stress, and malnutrition. Though there are effective p-phenylenediamine based hair dyes, they often cause allergy and systematic toxicity. Plants are popular a traditional remedy for the management of hair disorders. Due to their high chemical diversity, phytoproducts offer great promises to develop an effective and safe product to manage hair graying and melanogenesis disorders. The aim of the present article is to review plants with traditional uses and bio-activity against hair graying. An extensive literature search was conducted on PubMed, Science Direct, and Google Scholar databases using many combinations of the following keywords: plants used to treat gray hair, natural products, hair graying, melanogenesis, pigmentation, and tyrosinase activity. This review documented about sixty-one plants, including a summary of 47 plants frequently used in traditional medicine, and a brief review of fourteen plants showing promising activity against hair graying. The active constituents and the mechanisms by which active constituents exert anti-hair graying effects were also reviewed.
Taking a domestic approach to understanding a global phenomenon, I seek to illuminate how Black women communicate about, receive, and understand health information concerning a cultural health practice: skin whitening. Triangulating semi-structured in-depth interviews, autoethnography, field and participant observations, I completed a close look at skin whitening over four weeks of intensive observation and self-introspection. Findings reveal a complicated understanding of familial exchanges and non-knowledgeable representatives of products that vie for skin whitening products use without proper representation of health information and impacts. Implications reveal particular sources of health information as cultural reinforcers of skin whitening use.
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em>Background Skin lightening is very popular among women and some men of the Caribbean, and its popularity appears to be growing. The lightening of skin colour is done to produce a lighter complexion which is believed to increase attractiveness, social standing and improves one’s potential of being successful. Design and Methods Fifteen (15) common skin lightening creams found in pharmacies and cosmetic retailers throughout Trinidad and Tobago were evaluated for Mercury by Cold Vapor Atomic Absorption Spectrophotometry (CVAAS) and Arsenic by Hydride Generation Atomic Absorption Spectrophotometry (HGAAS). The results obtained were compared to global standards and previous research. Results Fourteen (14) of the fifteen samples analysed contained Mercury in the range of 0.473µg/g to 0.766µg/g. One sample had a Mercury content of 14,507.74±490.75µg/g which was over 14,000 times higher than the USFDA limit for mercury in cosmetics of 1µg/g. All samples contained Arsenic in the range 1.016µg/g to 6.612µg/g, which exceeds the EU limit for cosmetics of 0µg/g. Conclusion All the samples analysed contained significant amounts of Mercury and Arsenic and none of them can be considered “safe” for prolonged human use. The samples that contained Mercury levels which were lower than the USFDA contained Arsenic levels which exceeded the EU standard of 0µg/g in cosmetics. The popularity of these skin lightening creams in the Caribbean region places the population at elevated risk of chronic Mercury and Arsenic poisoning and possibly acute Mercury Poisoning.
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The enzyme tyrosinase is known to be a multifunctional copper-containing enzyme from the oxidase superfamily, which is the key protein involved in the biosynthesis of the large biological pigment, melanin. The enzyme catalyzes two distinct reactions of melanin biosynthesis, the hydroxylation of a monophenol and the conversion of an o-diphenol to the corresponding o-quinone. Inhibitors of this protein have a huge impact on industry and economy. So a number of research groups around the world are engaged and are expending much effort in the discovery of these inhibitors. In this report, we review the importance and applications of the recently designed synthetic tyrosinase inhibitors from our and other leading laboratories of the world, which have been published in recent years. In our continuing search for tyrosinase inhibitors from natural resources to semi- and full synthetic approaches, until now we discovered and reported a large number of mild to potent inhibitors of several classes, such as phenolics, terpenes, steroids, chalcones, flavonoids, alkaloids, long-chain fatty acids, coumarins, sildenafil analogs, bipiperidines, biscoumarins, oxadiazole, tetraketones, etc. The structure-activity relationships (SARs) of different classes of synthetic tyrosinase inhibitors have also been discussed in this review.
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Visible pigmentation in mammals results from the synthesis and distribution of melanin in the skin, hair bulbs, and eyes. The melanins are produced in melanocytes and can be of two basic types: eumelanins, which are brown or black, and phaseomelanins, which are red or yellow. In mammals typically there are mixtures of both types. The most essential enzyme in this melanin biosynthetic pathway is tyrosinase and it is the only enzyme absolutely required for melanin production. However, recent studies have shown that mammalian melanogenesis is not regulated solely by tyrosinase at the enzymatic level, and have identified additional melanogenic factors that can modulate pigmentation in either a positive or negative fashion. In addition, other pigment-specific genes that are related to tyrosinase have been cloned which encode proteins that apparently work together at the catalytic level to specify the quantity and quality of the melanins synthesized. Future research should provide a greater understanding of the enzymatic interactions, processing, and tissue specificity that are important to pigmentation in mammals.
The presence of ozone (O(3)) in photochemical smog is an important health concern. We hypothesized that the stratum corneum (SC), as the outermost skin layer and the permeability barrier of the skin, represents a sensitive target for O(3)-induced oxidative stress. To test this hypothesis, SKH-1 hairless mice were anesthetized and exposed for 2 h to O(3) by using two strategies: (i) single exposures to 0 (n = 12), 1 (n = 4), 5 (n = 4), and 10 (n = 4) ppm; and (ii) repeated daily exposures to 0 ppm (controls; n = 4) and 1 ppm (n = 4) for six consecutive days. New techniques based on the removal of SC by tape stripping were used to analyze the biologic effects of O(3) with respect to vitamin E depletion and lipid peroxidation. SC tissue was extracted from the tape and immediately analyzed by HPLC for vitamin E and malondialdehyde (MDA) concentrations. After in vivo exposure to increasing O(3) doses, vitamin E was depleted and MDA formation was increased, both in a dose-dependent manner. Remarkably, repeated low-level O(3) exposures resulted in cumulative oxidative effects in the SC: As compared with O(3) exposures of 0 ppm (alpha-tocopherol, 8.95 +/- 1.3 pmol per mg; gamma-tocopherol, 3.00 +/- 0.3 pmol per mg; MDA, 3.69 +/- 0.3 pmol per mg), vitamin E was depleted (alpha-tocopherol, 2.90 +/- 0.6 pmol per mg, p < 0.001; gamma-tocopherol, 0.5 +/- 0.1 pmol per mg, p < 0.001) and MDA levels were increased (4.5 +/- 0.2; p < 0.01). This report demonstrates the unique susceptibility of the SC to oxidative damage upon exposure to O(3).
Extracts from seventeen seaweeds were determined for tyrosinase inhibitory activity using mushroom tyrosinase with L-tyrosine as a substrate. Only one of them,Ecklonia stolonifera Okamura (Laminariaceae) belonging to brown algae, showed high tyrosinase inhibitory activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction from the methanolic extract ofE. stolonifera, led us to the isolation of phloroglucinol derivatives [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds1~5 were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with IC50 values of 92.8, 126, 33.2, 177, and 2.16 μg/mL, respectively. It was compared with those of kojic acid and arbutin, well-known tyrosinase inhibitors, with IC50 values of 6.32 and 112 μg/ mL, respectively. The inhibitory kinetics analyzed from Lineweaver-Burk plots, showed compounds1 and2 to be competitive inhibitors with Ki of 2.3×10-4 and 3.1×10-4 M, and compounds3×5 to be noncompetitive inhibitors with Ki of 1.9×10-5, 1.4×10-3 and 1.5×10-5 M, respectively. This work showed that phloroglucinol derivatives, natural compounds found in brown algae, could be involved in the control of pigmentation in plants and other organisms through inhibition of tyrosinase activity using L-tyrosine as a substrate.
An overview of agents causing hypopigmentation in human skin is presented. The review is organized to put forward groups of biological and chemical agents. Their mechanisms of action cover (i) tyrosinase inhibition, maturation and enhancement of its degradation; (ii) Mitf inhibition; (iii) downregulation of MC1R activity; (iv) interference with melanosome maturation and transfer; (v) melanocyte loss, desquamation and chemical peeling. Tyrosinase inhibition is the most common approach to achieve skin hypopigmentation as this enzyme catalyses the rate-limiting step of pigmentation. Despite the large number of tyrosinase inhibitors in vitro, only a few are able to induce effects in clinical trials. The gap between in-vitro and in-vivo studies suggests that innovative strategies are needed for validating their efficacy and safety. Successful treatments need the combination of two or more agents acting on different mechanisms to achieve a synergistic effect. In addition to tyrosinase inhibition, other parameters related to cytotoxicity, solubility, cutaneous absorption, penetration and stability of the agents should be considered. The screening test system is also very important as keratinocytes play an active role in modulating melanogenesis within melanocytes. Mammalian skin or at least keratinocytes/melanocytes co-cultures should be preferred rather than pure melanocyte cultures or soluble tyrosinase.
Thai Breadfruitûs Heartwood Extract: A New Approach to Skin Whitening
  • P Donsing
  • J Viyoch
Donsing,P., and Viyoch,J., Thai Breadfruitûs Heartwood Extract: A New Approach to Skin Whitening., SWU Sci. J. 2008; 24 (1): 9-23