A local Thai cultivar glutinous black rice bran: A source of functional compounds in immunomodulation, cell viability and collagen synthesis, and matrix metalloproteinase-2 and -9 inhibition

The rice bran from Kamklaing, a selected local Thai glutinous black rice cultivar (KRB), has gained interest for its nutraceutical composition and beneficial health effects. The ethanolic extract of KRB was prepared, analysed by HPLC and investigated for its biological effects. The results demonstrated that the KRB extracts had a high content of cyanidin-3-glucoside, caffeic acid and ferulic acid and possessed antioxidation and wound healing effect. This was associated with increasing migration and collagen synthesis in normal human dermal fibroblast cells when compared to the controls, MMP-2 and MMP-9 inhibitory effects in gelatin zymography, and immunomodulation with concentration-dependent bimodal effects in human monocytes. These results suggest that Kamklaing rice bran is a promising by-product that contains functional ingredients which may be useful in the control of skin aging and chronic disease development.