Depigmentation Activity of Curcuma xanthorrhiza and Zingiber zerumbet

Author

ZANARIAH UJANG, NURUL IZZA NORDIN, MAZITA MOHD DIAH, MOHD HELME MOHD HELAN, ROZANIDA ABDUL RAHMAN, AHMAD HAZRI ABDUL RASHID & HASNAH MOHD SIRAT

Proceeding

The 21st Annual Seminar of the Malaysian Natural Product Society.(Herbal Medicine:Natural Products Society), Palm Garden, Putrajaya Malaysia.

Date

22/11/2005

Keyword

Depigmentation, tyrosinase inhibition, melanin synthesis, Zingiber zerumbet, Curcuma xanthorrhiza

Abstract

Curcuma xanthorrhiza(locally known as temulawak) andZingiber zerumbet(local name lempoyang) are two perennial rhizomatous herbs belonging to the plant family Zingiberaceae. Both of the species are aromatic and contain high amounts of essential oils. The main phytochemical in the sesquiterpenoids fraction ofCurcuma xanthorrhizais xanthorrhizol while the major constituent ofZingiber zerumbetis zerumbone. In this work, extracts ofCurcuma xanthorrhizaandZingiber zerumbetwere prepared by various types of extraction method such as water, solvent and supercritical fluid extraction. The extracts and major phytochemical constituents were investigated for their depigmentation activity by using the tyrosinase inhibition assay. The enzyme tyrosinase is responsible for the production of melanin, the pigment that gives color to hair and skin and provides protection against UV rays. Based on the results of the tyrosinase inhibition study, it was found that the extracts ofCurcuma xanthorrhizaandZingiber zerumbetinteract synergistically to strongly inhibit tyrosinase activity. Xanthorrhizol and zerumbone, the sesquiterpene isolated fromCurcuma xanthorrhizaandZingiber zerumbetrespectively displayed higher depigmentation activity compared to the total extracts. The most economical extract, prepared from solvent extraction was further investigated for its depigmentation effect. The extract was incorporated into topical formulations and  in vitro and in vivo studies were carried out to determine the ability of the extract to inhibit melanin synthesis. The cytotoxic effect of the extracts towards melanocytes, the skin cells that produce melanin was also conducted using the neutral red uptake method.