Protective effects of lotus stamen extract on UV-B-irradiated skin cells activities

Abstract

Traditionally, Nelumbo nucifera has been used as a tonic and stimulant. The aim of this study was to clarify a protective effect regarding UV-B induced inflammation and melanogenesis activities of the crude extract of the dried lotus stamen extract. The compounds of the extract were isolated by column chromatography. The anti-oxidant EC50 value of the crude extract was 0.0353 mg/mL while the EC50 values of the isolated compounds of kaempferol and kaempferol 3-O--Dglucopyranoside were 0.0030 and 0.0077 mg/mL, respectively, which were observed by DPPH assay. The tyrosinase inhibitory activity was tested by tyrosinase enzyme. The anti-tyrosinase IC50 value of the crude was 0.0192 mg/mL while the isolated kaempferol was 0.0496 mg/mL. To determine the anti-inflammatory activity, the molecular targets for the extract action were TNF-α and IL-6. The release of TNF-α and IL-6 was significantly reduced in UV-B-induced keratinocytes pretreated with the crude extract at concentrations from 25 to 100 μg/mL. Moreover, the crude extract was found to inhibit the melanin overproduction of B16F1 induced by α-MSH.

Keywords

• lotus stamen
• protective effect
• melanogenesis inhibitory activity
• anti-oxidant activity
• anti-inflammatory activity