salicylates and hydroquinone

Postinflammatory hyperpigmentation (PIH) has posed a substantial challenge for patients with higher Fitzpatrick skin types, specifically types III to VI. Treatment modalities pose a number of limitations due to the number of treatments required, potential side effects, and overall efficacy. Fortunately, multiple therapies have been delineated that can be moderately to highly efficacious in treating PIH in patients with skin of color. This article will review some of these modalities and procedures for this common patient concern.

Topics: Chemexfoliation; Dermatitis; Dermatologic Agents; Dicarboxylic Acids; Drug Combinations; Ethanol; Glycolates; Humans; Hydroquinones; Hyperpigmentation; Inflammation; Keratolytic Agents; Lactic Acid; Pyrones; Resorcinols; Salicylates; Salicylic Acid; Skin Pigmentation; Tretinoin

Use of cosmetic products to bleach or lighten the skin is common among dark-skinned women in some sub-Saharan African countries. Long-term use of some pharmacologic compounds (e.g. hydroquinone, glucocorticoids and mercury) can cause adverse effects including dermatologic disorders such as dyschromia, exogenous ochronosis, acne and hypertrichosis, prominent striae, tinea corporis, pyoderma, erysipelas, scabies, and contact dermatitis and systemic complications such as hypertension, hypercorticism or surrenal deficiency, and mercurial nephropathy.

Topics: Africa; Black People; Cosmetics; Dermatologic Agents; Glucocorticoids; Humans; Hydroquinones; Mercury; Salicylates; Skin Diseases; Skin Pigmentation

Effective cosmetic surgery depends on proper preparation of the skin prior to the procedure, excellent wound care, and an appropriate postoperative skin maintenance program. Accomplishing this goal requires a thorough understanding of topical agents. Substances applied to the skin can alter barrier function, permeability, transepidermal water loss, immune response, wound repair, vasostability, collagen deposition, epidermal turnover, and melanin formation, to name a few. Each of these skin characteristics can affect the quality of the end surgical result. This article discusses topical agents used in association with cosmetic surgery.

Topics: Administration, Topical; Adolescent; Adult; Aged; Ascorbic Acid; Carotenoids; Chemexfoliation; Dicarboxylic Acids; Female; Humans; Hydroquinones; Hydroxy Acids; Keratolytic Agents; Male; Middle Aged; Postoperative Care; Preoperative Care; Retinoids; Salicylates; Skin Aging; Skin Care; Skin Pigmentation; Sunscreening Agents; Surgery, Plastic; Vitamin A; Vitamin E

Topics: Administration, Cutaneous; Aged; Cosmetics; Dermatitis, Contact; Female; Humans; Hydroquinones; Hyperpigmentation; Patch Tests; Salicylates; Skin; Skin Cream; Skin Pigmentation; Sunscreening Agents; Treatment Outcome

The volatile compounds that constitute the fruit aroma of ripe tomato (Solanum lycopersicum) are often sequestered in glycosylated form. A homology-based screen was used to identify the gene SlUGT5, which is a member of UDP-glycosyltransferase 72 family and shows specificity towards a range of substrates, including flavonoid, flavanols, hydroquinone, xenobiotics and chlorinated pollutants. SlUGT5 was shown to be expressed primarily in ripening fruit and flowers, and mapped to chromosome I in a region containing a QTL that affected the content of guaiacol and eugenol in tomato crosses. Recombinant SlUGT5 protein demonstrated significant activity towards guaiacol and eugenol, as well as benzyl alcohol and methyl salicylate; however, the highest in vitro activity and affinity was shown for hydroquinone and salicyl alcohol. NMR analysis identified isosalicin as the only product of salicyl alcohol glycosylation. Protein modelling and substrate docking analysis were used to assess the basis for the substrate specificity of SlUGT5. The analysis correctly predicted the interactions with SlUGT5 substrates, and also indicated that increased hydrogen bonding, due to the presence of a second hydrophilic group in methyl salicylate, guaiacol and hydroquinone, appeared to more favourably anchor these acceptors within the glycosylation site, leading to increased stability, higher activities and higher substrate affinities.

Topics: Amino Acid Sequence; Benzyl Alcohol; Benzyl Alcohols; Catalytic Domain; Chromosomes; Cloning, Molecular; Escherichia coli; Eugenol; Gene Expression; Glycosyltransferases; Guaiacol; Hydrogen Bonding; Hydroquinones; Models, Molecular; Molecular Sequence Data; Phenols; Phenylethyl Alcohol; Phylogeny; Plant Proteins; Plant Structures; Recombinant Proteins; Salicylates; Sequence Homology, Amino Acid; Solanum lycopersicum; Substrate Specificity; Uridine Diphosphate Glucose; Volatile Organic Compounds

The violet color complex FeSal+ was prepared by reaction of Salicylic acid and Ferric Chloride in acidic medium up to pH 3.5 in formate buffer at ionic strength 0.1 M. Reduction kinetics of FeSal+ complex at pseudo first order condition have been studied spectrophotometrically by a reductant i.e. Hydroquinone. Reduction behaviour shows that reduction is much fast and pH dependent. A mechanism to account for observation is also proposed along with the rate law.

Topics: Ferric Compounds; Hydrogen-Ion Concentration; Hydroquinones; Indicators and Reagents; Kinetics; Oxidation-Reduction; Salicylates; Spectrophotometry, Infrared

Many women of childbearing age from sub-Saharan Africa use topical skin lighteners, some of which present a risk of toxic systemic effects. The goals of this study were to evaluate, in this environment, the frequency of this practice during pregnancy, as well as eventual consequences on pregnancy. Ninety-nine women from 6 to 9 months pregnant were randomly selected among those attending a standard maternal centre in Dakar for a prenatal visit. Investigations consisted of questions about the use of skin lighteners, a standard clinical examination, follow-up until delivery and a morning blood sample for plasma cortisol levels. Sixty-eight of the 99 selected women used skin lighteners during their current pregnancy, the main active ingredients being hydroquinone and highly potent steroids (used by 64 and 28 women, respectively). No difference in the main outcomes of pregnancy were found between skin-lightener users and the others; however, women using highly potent steroids, when compared with those who did not, had a statistically significant lower plasma cortisol level and a smaller placenta, and presented a higher rate of low-birth-weight infants. Skin lightening is a common practice during pregnancy in Dakar, and the use of steroids may result in consequences in the mother and her child.

Topics: Adolescent; Adult; Caustics; Cosmetics; Dermatologic Agents; Female; Hazardous Substances; Humans; Hydroquinones; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Salicylates; Senegal; Steroids

The effect of doxorubicin on oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) by lactoperoxidase and hydrogen peroxide has been investigated. It was found that: (1) oxidation of ABTS to its radical cation (ABTS*(+)) is inhibited by doxorubicin as evidenced by its induction of a lag period, duration of which depends on doxorubicin concentration; (2) the inhibition is due to doxorubicin hydroquinone reducing the ABTS*(+) radical (stoichiometry 1: 1.8); (3) concomitant with the ABTS*(+) reduction is oxidation of doxorubicin; only when the doxorubicin concentration decreases to a near zero level, net oxidation of ABTS could be detected; (4) oxidation of doxorubicin leads to its degradation to 3-methoxysalicylic acid and 3-methoxyphthalic acid; (5) the efficacy of doxorubicin to quench ABTS*(+) is similar to the efficacy of p-hydroquinone, glutathione and Trolox C. These observations support the assertion that under certain conditions doxorubicin can function as an antioxidant. They also suggest that interaction of doxorubicin with oxidants may lead to its oxidative degradation.

Topics: Antibiotics, Antineoplastic; Benzothiazoles; Chromans; Doxorubicin; Free Radicals; Glutathione; Hydrogen Peroxide; Hydroquinones; Lactoperoxidase; Oxidants; Oxidation-Reduction; Phthalic Acids; Salicylates; Sulfonic Acids; Thiazoles