Abstract
Phaseolus aureus (mung bean), Leguminosae, has been used as an antidote from the ancient time. Especially, it has been widely used for cleaning face and skin in oriental countries. Although several constituents such as fatty acids, phytoallexin and phaseol derivatives were reported in P. aureus and related species including seedlings, there has been a few report to describe its biological activity. Therefore, in this investigation, the ethanol extract from P. aureus was obtained and its biological activities including the antioxidative and anti-inflammatory activities were studied. The 70% ethanol extract from P. aureus showed dose-dependent antioxidative activity (52.3% inhibition at 4 mg/ml) against lipid peroxidation assay, while the extract did not show the inhibitory activity of superoxide radical formation. The extract also showed the topical anti-inflammatory activity against croton-oil and arachidonic acid induced mouse ear edema test (18-19% inhibition at 7.5 mg/ear) as well as mild inhibitory activity against picryl chloride induced delayed hypersensitivity in mouse. For investigating active principles, vitexin and isovitexin (apigenin C-glycoside) as flavonoids, and adenosine were isolated from the extract using silica gel chromatography. The actual contents of vitexin and isovitexin were found to be 3.7 and 2.4 mg/g extract, respectively. Vitexin and isovitexin showed the antioxidative activity. They showed the topical anti-inflammatory activity, although the activities were not potent compared to the reference compounds. These results suggested that vitexin and isovitexin may be, at least in part, the compounds contributing the antioxidative activity in vitro and the topical anti-inflammatory activity of P. aureus in vivo. All results of present study might be one of the scientific rationale in using mung bean for skin care from the ancient time.