Natural Melanogenesis Inhibitor, Antioxidant, and Collagen Biosynthesis Stimulator of Phytochemicals in Rice Bran and Husk Extracts from Purple Glutinous Rice (Oryza sativa L. cv. Pieisu 1 CMU) for Cosmetic Application

The study investigated the potential cosmetic applications of extracts from purple glutinous rice (Oryza sativa L. cv. Pieisu 1 CMU), focusing on their effects on skin hyperpigmentation and aging. The defatted rice bran (DFRB) extract was found to be the most effective in inhibiting mushroom tyrosinase and melanin production in stimulated B16 cells, showing a whitening effect comparable to arbutin. Both DFRB and husk (H) extracts demonstrated strong antioxidant activities and effectively inhibited collagen degradation in fibroblasts exposed to oxidative stress, performing comparably to l-ascorbic acid. These findings suggested that rice-processing wastes like DFRB and H could serve as natural ingredients in anti-aging and skin-whitening cosmetic products.