A Comparison of the Cytotoxic Potential of Standardized Aqueous and Ethanolic Extracts of a Polyherbal Mixture Comprised of Nigella sativa (seeds), Hemidesmus indicus (roots) and Smilax glabra (rhizome)

Sameera R Samarakoon; Ira Thabrew; Prasanna B Galhena; Dilip De Silva; Kamani H Tennekoon

A Comparison of the Cytotoxic Potential of Standardized Aqueous and Ethanolic Extracts of a Polyherbal Mixture Comprised of Nigella sativa (seeds), Hemidesmus indicus (roots) and Smilax glabra (rhizome)

Articles

Abstract

Pharmacognosy Research,2010,2,6,335-342.

DOI:10.4103/0974-8490.75451

Published:January 2011

Type:Original Article

Authors:

Author(s) affiliations:

Sameera R Samarakoon¹, Ira Thabrew¹, Prasanna B Galhena², Dilip De Silva³, Kamani H Tennekoon¹

¹Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Cumarathunga Munidasa Mawatha, 90, Colombo 3, Sri Lanka.

²Department of Biochemistry and Clinical Chemistry, Faculty of Medicine, University of Kelaniya, Talagoole Road, Ragama, Sri Lanka.

³Department of Chemistry, Faculty of Science, University of Colombo, Sri Lanka.

Abstract:

Background: A decoction (hot-water extract) comprised of Nigella sativa (seeds), Hemidesmus indicus (roots), and Smilax glabra (rhizome) has been reported to prevent chemically-induced hepatocarcinogenic changes in rats and to exert significant cytotoxic effects on human hepatoma (HepG2) cells. However, the decoction used in previous studies to determine cytotoxicity was not standardized. Further, during preparation of pharmaceuticals for clinical use, it is more convenient to use an ethanolic extract. Therefore this study was carried out to (a) develop standardized aqueous and ethanolic extracts of the plant mixture (N. sativa, H. indicus, and S. glabra) used in the preparation of the original decoction, and (b) compare the cytotoxic effects of these two extracts by evaluating cytotoxicity to the human hepatoma (HepG2) cell line. Methods: Aqueous and ethanolic extracts have been standardized by evaluating organoleptic characters, physicochemical properties, qualitative and quantitative analysis of chemical constituents, and analysis of High Performance Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC) profiles. Cytotoxic potentials of the above standardized extracts were compared by evaluating their effects on the survival and overall cell activity of HepG2 cells by use of the 3-(4, 5-dimethylthiazol-2yl) -2, 5 - biphenyl tetrazolium bromide (MTT) and Sulphorhodamine B (SRB) assays. Results: Results from MTT and SRB assays demonstrated that both extracts exerted strong dose-dependent in vitro cytotoxicity to HepG2 cells. The standardized aqueous extract showed a marginally (though significantly, P<0.05) higher cyotoxic potential than the ethanolic extract. Thymoquinone, an already known cytotoxic compound isolated from N. sativa seeds was only observed in the standardized ethanolic extract. Thus, compounds other than thymoquinone appear to mediate the cytotoxicity of the standardized aqueous extract of this poly-herbal preparation. Conclusion: It may be concluded that results obtained in the present study could be used as a diagnostic tool for the correct identification of these aqueous or ethanolic extracts and would be useful for the preparation of a standardized pharmaceutical product that may be used in the future for clinical therapy of hepatocellular carcinoma