Po-Ju Lai^{1, 2}, Erl-Shyh Kao³, Sin-Rong Chen¹, Yu-Ting Huang¹, Chau-Jong Wang^{1, 4,}, Hui-Pei Huang^{1, 5,}

Nelumbo nucifera leaves extracts (NLE) has been suggested to provide antioxidant, anti-obesity and anticancer effects. However, the research on the anti-melanogenetic effect of NLE was little. Here, we reported that NLE and Gallic acid (GA, major ingredients of NLE) exhibit the hypopigmentary effect in B16F1 cells. NLE and GA showed potent inhibitory effects on tyrosinase, microphthalmia-associated transcription factor (MITF), and tyrosinase-related protein-1 (TRP-1) protein production. The phosphorylation of intracellular protein kinase A (PKA) and cAMP response element-binding protein (CREB) were also decreased, revealing potent anti-melanogenic effects of NLE and GA. However, NLE showed the better effect than GA on reducing melanin formation, implying the importance of the synergism of polyphenolic compounds of NLE. Furthermore, NLE inhibited skin melanogenesis and epidermal hyperplasia of guinea pigs caused by irradiation through attenuating ERK and CREB activation. NLE reduced skin melanogenesis and epidermal hyperplasia induced by UVB in guinea pigs through downregulation ERK and CREB pathways, and the following decreasing of MITF, tyrosinase and TRP-1 expression. These results demonstrated the potential which NLE as an ingredient of hypopigmentary cosmetics.

CREB, gallic acid, melanogenesis, nelumbo nucifera leaves extracts (NLE), tyrosinase