Bio-Guided Chromatographic Fractionation of Lycium shawii Roem & Schult, Family Solanaceae, Growing in Egypt

Abstract

Lycium (Boxthorn) is a genus of the nightshade family (Solanaceae), comprises about 90 species of thorny shrubs, long shoots with alternate leaves or short shoots with cluster of leaves, usually terminating in a spine (Boulos, 1999). Genus Lyciumoccurs worldwide and has its natural range on all temperate and tropical continents, with centers of diversity in southern South America, southern Africa and southwestern North America. (Rachel A. Levin, et al. 2011).In Egypt; the genus is represented by three species distributed in the Arabian Desert (east of the Nile), the Red Sea coastal region, Gebel Elba, surrounding mountains and the South east corner of Egypt at the Sudan frontier. (Boulos, 1999). Phytochemical studies concerning Lyciumspecies had attracted the attention of many authors. Although ca. 90 species of Lycium are distributed all over the world, only twelvespecies had attracted the attention of several authors from the phytochemical and biological point of view, Lycium shawii R. has not studied well as compared with other Lycium species. It was, thus, interesting to carry out diverse biological studies on Lycium shawii R. growing in Egypt to rationalize its possible use as a medicinal plant. The present study includes: Part I: Study of the biological activities of L. shawii R. 1. Study of the Cytotoxic Activity The total ethanolic extract of Lycium shawii R. and the fraction thereof (n-hexane, methylene chloride, ethyl acetate, n-butanol and methanol) were assayed by SRB assay against three cancer cells, HEPG2, MCF7 and HCT116. n-hexane fractionof L. shawii R. exhibits potent inhibition of cell growth against HCT116 (IC50= 7.80±0.11µg/ml), methylene chloride fraction has the most potent cytotoxic activity against MCF7 cancer cells with IC50of 11.00±0.08µg/ml, while the n-butanol fraction has the most potent cytotoxic activity against HEPG2 cancer cell with IC50of 9.00±0.05µg/ml. 2. Study of the free Radical Scavenging Activity The total ethanolic extract of L. shawii R. and the fraction thereof (n-hexane, methylene chloride, ethyl acetate, and n-butanol were assayed in vitro using DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical spectrophotometric assay. The ethyl acetate fraction has the most potent antioxidant activity (SC50=55.4µg/ml), compared to the standard Rutin (IC50=24.03µg/ml). These results indicate that the high antioxidant activity is probably due to the presence of polyphenols. 3. Study of the Hepatoprotective Activity The total ethanolic extract of L. shawii R. and the fraction thereof (n-hexane, methylene chloride, ethyl acetate and n-butanol were assayed against CCL4- induced hepatotoxicity. The ethyl acetate fraction possess the most potent hepatoprotective activity against CCL4-induced hepatoxicity as compared to standard silymarin. There was no histopathological alteration observed and a normal histological structure of liver cells was recorded in control group, pretreatment with ethyl acetate fractionshowed normal hepatocytes with minimum fatty changes, portal vein congestion and mild inflammatory cell infiltration around portal vein, compared to control group.