Red-koji vinegar is a Monascus -involved and acetic acid fermentation-derived traditional product, in which the presence of monacolin K and citrinin has attracted public attention. In this study, red-koji wine was prepared as the substrate and artificially supplemented with monacolin K and citrinin and subjected to vinegar fermentation with Acetobacter starter. After 30 days of fermentation, 43.0 and 98.1% of the initial supplements of monacolin K and citrinin were decreased, respectively. During fermentation, acetic acid contents increased, accompanied by decreases of ethanol and lactic acid contents and pH values. The contents of free amino acids increased while the contents of other organic acids, including fumaric acid, citric acid, succinic acid, and tartaric acid, changed limitedly. Besides, increased levels of total phenolics in accordance with increased antioxidative potency, α,α-diphenyl-β-picrylhydrazyl scavenging, and xanthine oxidase inhibitory (XOI) activities were detected. It is of merit that most citrinin was eliminated and >50% of the monacolin K was retained; contents of free amino acids and total phenolics along with antioxidant and XOI activities of the red-koji vinegar were increased after fermentation.

Tea (Camellia sinensis) contains high level of antioxidant elements and is a well-known beverage consumed worldwide. The purpose of this study is to compare different concentrations of green tea, black tea, oolong tea 861, oolong tea 732, and jasmine green tea. These five types of tea extracts were known to have antioxidative properties, reducing power, and metal ion chelating activity. The current study compared these five extracts in terms of their inhibiting effects on human malignant melanoma: A2058 and A375. To determine the cell viability between normal cell and malignant melanoma cells, an MTT assay was applied to evaluate the cytotoxic potential on human melanoma cells, with all tea extracts showing decreased cell viability with increasing tea extract concentrations. Cytotoxicity on HaCat (normal skin cells) showed no effect on the cell viabilities at lower concentrations of the tea extracts. These results suggest the antioxidative effect of five tea extracts that protect against oxidation and melanoma production, with green tea and jasmine green tea showing the lowest cell viability when tested against malignant melanoma cells.

BACKGROUND Hibiscus sabdariffa is commonly used in daily life and its extract is applied widely in food and cosmetics. However, it has not been evaluated for its anti‐aging effects. RESULTS Hibiscus sabdariffa calyx aqueous extract (HSCAE) has shown potential collagenase activity suppression effects, together with tyrosinase activity inhibition, and anti‐oxidation as a free radical scavenger. The current investigation demonstrated that HSCAE was not cytotoxic in skin fibroblasts, and it significantly decreased ultraviolet B (UVB)‐induced reactive oxygen species (ROS) on a flow cytometry assay. Moreover, HSCAE reduced matrix metalloproteinase (MMP) expression, increased tissue inhibition of metalloproteinase (TIMP)‐1 level, and enhanced collagen content by inhibiting collagenase activity. It also blocked mRNA and protein expressions of melanin production pathway key factors, including the microphthalmia‐associated transcription factor (MITF), tyrosinase, tyrosinase‐related protein‐1 (TRP‐1), and dopachrome tautomerase‐2 (TRP‐2). CONCLUSION These results demonstrated, for the first time, the potential of HSCAE as a natural antioxidant with the ability to maintain collagen production and to decrease melanin syntheses under UVB radiation, for anti‐aging effects. © 2019 Society of Chemical Industry

No abstract