Mechanistic studies of anti-hyperpigmentary compounds: elucidating their inhibitory and regulatory actions.

Searching for depigmenting agents from natural sources has become a new direction in the cosmetic industry as natural products are generally perceived as relatively safer. In our previous study, selected Chinese medicines traditionally used to treat hyperpigmentation were tested for anti-hyperpigmentary effects using a melan-a cell culture model. Among the tested chemical compounds, 4-ethylresorcinol, 4-ethylphenol and 1-tetradecanol were found to possess hypopigmentary effects.

Application of a combined sulphorhodamine B and melanin assay to the evaluation of Chinese medicines and their constituent compounds for hyperpigmentation treatment.

Aim Of The Study: To investigate the efficacy of traditional Chinese medicine (TCM) in the treatment of hyperpigmentation problems, extracts of herbs selected based on traditional Chinese medical literature were screened.

Materials And Methods: Forty extracts were extracted from 10 selected herbs using hexane, dichloromethane, methanol and water. They were then screened using melan-a cells, an immortalized non-tumorigenic mouse melanocyte cell line.

Diarylheptanoids and a monoterpenoid from the rhizomes of Zingiber officinale: antioxidant and cytoprotective properties.

Three new diarylheptanoids and one new monoterpenoid were isolated from the rhizomes of Zingiber officinale together with four known diarylheptanoids, 5-8. Their structures were elucidated mainly by spectroscopic methods, and they were deduced as 5-[4-hydroxy-6-(4-hydroxyphenethyl)tetrahydro-2 H-pyran-2-yl]-3-methoxybenzene-1,2-diol (1), sodium (E)-7-hydroxy-1,7-bis(4-hydroxyphenyl)hept-5-ene-3 S-sulfonate (2), sodium (E)-7-hydroxy-1,7-bis(4-hydroxyphenyl)hept-5-ene-3 R-sulfonate (3), and hydroxycineole-10-O-beta-D-glucopyranoside (4), respectively. Among the isolated compounds, compounds 1, 5, and 8 exhibited strong superoxide anion radical scavenging activities in a phenazine methosulfate-NADH system.

Antioxidant actions of phenolic compounds found in dietary plants on low-density lipoprotein and erythrocytes in vitro.

Objective: There is increasing interest in the study of the antioxidant actions of plant phenolic compounds as evidence shows that consumption of plant products rich in these compounds contributes to protection from a number of ailments including cardiovascular diseases. In the present study, the antioxidant effects of selected phenolic compounds from dietary sources, namely barbaloin, 6-gingerol and rhapontin, were investigated.

Methods: Low-density lipoprotein (LDL), erythrocytes and erythrocyte membranes were subjected to several in vitro oxidative systems.