Abstract #922: Cancer chemopreventive potential of 1,2,4-trihydroxynaphthalene glucosides of Henna

Henna is a powder of the leaves of Lawsonia inermis. This powder is used mainly as a pigment for coloring skin, hair, fingernails, leather, silk and wool. Earlier, we had assessed the anticancer potential of henna powder using in vitro and in vivo assays. Henna inhibited tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA) - induced activation of Epstein-Barr virus early antigen in Raji cells. This indicated the anticancer property of henna powder. The activity of henna was also studied in the ultraviolet light-B (5430 j/m²) - induced and TPA- promoted two stage mouse skin carcinogenesis model. Topical application of henna decreased tumor incidence in this model system by 70% and tumor multiplicity by 40% at ten weeks of treatment. The coloring property of henna is attributed to lawsone, 2-hydroxy-1, 4-naphthaquinone. However, this naphthoquinone does not occur as such in the leaves. Instead it appears to be derived from the glucosides of 1, 2, 4-trihydroxnaphthalene by enzymatic hydrolysis followed by oxidation of the resulting aglucone, 1, 2, 4-trihydoxynaphthalene. In this study we have evaluated the anticancer potential of the extract of henna, which was free of lawsone, but contained the glucosides of 1, 2, 4-trihydroxynaphthalene. We have also isolated the trihydroxy naphthalene glucosides and are currently assessing their anticancer potential. In vitro and in vivo bioassays indicated that the 1, 2, 4-trihydoxynaphthalene glucosides, which are precursors of lawsone may contribute to the anticancer properties of henna preparations. The cancer inhibitory effect of topically applied henna powder free of lawsone was also demonstrated in the peroxynitrite induced mouse skin carcinogenesis model system. In this model system, henna decreased tumor incidence by 55% and tumor multiplicity by 57% after 11 weeks of treatment. These data suggest that henna naphthalene glucosides as well as the major coloring pigment, lawsone generated from the glucosides may be useful as cancer preventive agents.

Citation Information: In: Proc Am Assoc Cancer Res; 2009 Apr 18-22; Denver, CO. Philadelphia (PA): AACR; 2009. Abstract nr 922.