Hispanic/Latinos and Skincare: Disparities in Product Development, Marketing, and Toxicity

“Hispanic” and “Latino” (also known as Mestizo) describe a diverse racial and ethnic group, with a range of cultures, languages, and biological ancestry. It includes individuals of Mexican, Central-to-South American, and Spanish-Caribbean (eg, Cuban, Puerto Rican, and Dominican) descent.1 Individuals of Hispanic/Latino race and ethnicity represent a heterogenous group of people with different skin tones and Fitzpatrick phototypes. Hispanic/Latinos are the fastest growing population in the United States (US) - projected to increase from 55 million in 2014 to 119 million in 2060, an increase of 115%.2 By 2060, more than one-quarter (29%) of the US is projected to be Hispanic/Latino.2.

Formulation and evaluation of antioxidant and antityrosinase activity of Polygonum amplexicaule herbal gel

Medicinal plants are long been used for pharmaceutical and cosmetic industry. Among medicinal plants, Polygonum amplexicaule of family polygonaceae has traditional use in medicines and skin care. P. amplexicaule belongs to genus Polygonum that contains several important phytochemicals and considered as a rich source of antioxidants. The present study was designed to formulate herbal gel containing P. amplexicaule extract and evaluate its different physical properties as well as antioxidants and antityrosinase activities. Chitosan gel base was used as gelling agent and different gel formulations were prepared by different concentrations of extracts and polymers. Physical properties like pH, colour, odour, appearance and homogeneity, spreadability, extrudability and stability were optimized and analysed. A stable gel formulation containing 1% chitosan gel base and 5% plant extract was prepared that showed good appearance and homogeneity, easily spread ability and excellent extrudability. This gel formulation was tested for antioxidant and skin whitening properties by DPPH free radical scavenging assay and tyrosinase inhibition assay respectively and ascorbic acid was used as reference standard. DPPH scavenging activity with an IC₅₀ value of 0.446 mg/mL and tyrosinase inhibition activity with an IC₅₀ value of 0.805 mg/mL was observed and results indicated that this herbal gel formulation has a good potential for cosmetic use.

Identification of new arylsulfide derivatives as anti-melanogenic agents in a zebrafish model

A series of aryl sulfide derivatives was synthesized and evaluated for their anti-melanogenic activities. Several compounds, including 3e, 3i and 3q exhibited good anti-melanogenic activities. Among the derivatives, compound 3i showed good inhibitory effects against melanin synthesis and showed no toxicity in reconstituted human eye and skin tissues.

Biochemical Mechanism of Rhododendrol-Induced Leukoderma

RS-4-(4-hydroxyphenyl)-2-butanol (rhododendrol (RD))-a skin-whitening ingredient-was reported to induce leukoderma in some consumers. We have examined the biochemical basis of the RD-induced leukoderma by elucidating the metabolic fate of RD in the course of tyrosinase-catalyzed oxidation. We found that the oxidation of racemic RD by mushroom tyrosinase rapidly produces RD-quinone, which gives rise to secondary quinone products. Subsequently, we confirmed that human tyrosinase is able to oxidize both enantiomers of RD. We then showed that B16 cells exposed to RD produce high levels of RD-pheomelanin and protein-SH adducts of RD-quinone. Our recent studies showed that RD-eumelanin-an oxidation product of RD-exhibits a potent pro-oxidant activity that is enhanced by ultraviolet-A radiation. In this review, we summarize our biochemical findings on the tyrosinase-dependent metabolism of RD and related studies by other research groups. The results suggest two major mechanisms of cytotoxicity to melanocytes. One is the cytotoxicity of RD-quinone through binding with sulfhydryl proteins that leads to the inactivation of sulfhydryl enzymes and protein denaturation that leads to endoplasmic reticulum stress. The other mechanism is the pro-oxidant activity of RD-derived melanins that leads to oxidative stress resulting from the depletion of antioxidants and the generation of reactive oxygen radicals.

"The fairer the better?" Use of potentially toxic skin bleaching products

BACKGROUND

Skin bleaching is a widespread phenomenon in spite of their potentially toxic health effects.

OBJECTIVES

This study aimed to determine if such products are used in Sweden in particular by pregnant women, furthermore to explore immigrant women's view skin bleaching.

METHODS

455 pregnant women completed a questionnaire, which were statistically analysed. Focus groups and individual interviews were conducted with immigrant women, content analysis was used to assess the data.

RESULTS

Skin bleaching products were used by 2.6% of pregnant women, significantlly more by women born in non-European countries. Motivating factors were associated with the concept of beauty together with social and economic advantages. The women had low awareness of the potential health risks of the products. Regulations on the trade of skin bleaching products have not effectively reduced the availability of the products in Sweden nor the popularity of skin bleaching.

CONCLUSION

There is need for further research especially among pregnant women and possible effects on newborns. Products should be tested for toxicity. Public health information should be developed and health care providers educated and aware of this practice, due to their potential negative health implications.

Effect of novel cyclohexane diester and benzene diester derivatives on melanogenesis

In order to investigate potent whitening agents, we synthesized 15 cyclohexane diester derivatives and 15 benzene diester derivatives. To evaluate their structure-cytotoxicity relationships, we performed cell cytotoxicity tests on B16F10 mouse melanoma cells. To understand their whitening effects, melanin synthesis inhibitory activities in B16F10 cells and mushroom tyrosinase inhibitory activities were performed. In most cases, cell cytotoxicity was observed to be lower in 1,3-diester than in 1,2- and 1,4-diesters; when it came to the structural isomer of the side chain, all derivatives except the 1,2-cyclohexane diester derivatives showed lower cell cytotoxicity in the branch type of the side chain than in the linear type. Among the compounds evaluated, the compounds cyclohexane-1,3-diyl bis(decanoate), cyclohexane-1,4-diyl dioctanoate, and 1,3-phenylene bis (2-ethylhexanoate) emerged as potent melanin synthesis inhibitors. Our goal was to determine the expression levels of proteins involved in melanogenesis, Western blotting and RT-PCR showing that these compounds decreased tyrosinase, TRP-1, and TRP-2 while demonstrating significantly low cytotoxicity.

Skin-lightening practices and mercury exposure in the Somali community

Somali women often use creams and soaps to lighten skin tone, fade freckles or get rid of age spots. Use of these products raises a health concern, as some have been found to contain mercury. This article describes an investigation that involved interviewing Somali women about skin-lightening practices and the products they use and then testing those products for mercury. Twenty-seven samples of products purchased at markets in Minneapolis and St. Paul were analyzed bythe Minnesota Department of Health for specific mercury levels. Eleven of the 27 (47%) were found to contain mercury. Some exceeded the current FDA threshold of 1 part per million. This has prompted both state and federal health officials to issue warnings about the use of these products.