Phytochemical and Biological Studies on Albizia anthelmintica Family Fabaceae

Abstract

Family Fabaceae is one of the largest plant families that comprise a lot of valuable medicinal plants. Genus Albizia consists of about 150 species, one of them is Albizia anthelminticaBrongn. This plant was chosen for this study since nothing could be traced in literature regarding its cytotoxic activity. The present study is divided into two parts: 1- Biological investigation of the main fractions of the 80% aqueous methanol leaf extract of Albizia anthelmintica and isolated compounds. 2- Phytochemical investigation of the 80% aqueous methanol leaf extract of Albizia anthelmintica. Part I: Biological investigation of the 80% aqueous methanol leaf extract of Albizia anthelmintica Family Fabaceae This includes: • Evaluation of the cytotoxic activity of the extract, the main fractions, and the pure isolated compounds (in-vitro) on human hepatocellular carcinoma (HepG 2 cell line) and human colon carcinoma (HCT-116 cell line). • Evaluation of the molluscicidal activity of the extract on Bimpholariaalexandrina(the host snail of Schistisomamansonai), the cercaria and meracidia of Schistisomamansonai. This work represents the first study regarding the cytotoxic activity of A. anthelmintica leaves, where the acetone sol. and acetone insol. fractions of the 80% aqueous methanol extract, the four main sub-fractions obtained from acetone insol. fraction, and the four isolated saponins were evaluated for their cytotoxic activity on liver cancer (HepG 2 cell line) and human colon cancer (HCT-116 cell line) usingMTT assay and doxorubicin as a standard cytotoxic drug. The acetone insoluble fraction (rich in saponins) showed potent cytotoxic activity on HepG 2 and HCT-116 cell lines with IC50values of 1.5 µg/mL and 2.3 µg/mL, respectively. While the acetone soluble fraction showed less potent cytotoxic activity with IC50 values of 5.62 µg/mL and 18.1µg/mL, respectively. Sub-fraction III (eluted with 75% methanol) and sub-fraction IV (eluted with 100% methanol) were more potent than sub-fraction I (eluted with distilled water) and sub-fraction II (eluted with 50% methanol) as they are rich in saponins. Regarding cytotoxicity of the isolated saponins, compound 3(which is reported in nature for the first time) exhibited the most potent cytotoxic activity among other saponins on HepG2 cell line with an IC50 value of 3.91 µg/mL, while compound 2 which is also a new compound exhibited the most potent cytotoxic activity among other saponins on HCT-116 cell line with an IC50 value of 5.66 µg/mL. In this study the molluscicidal activity of the acetone soluble and the acetone insoluble fractions was evaluated for the first time on Biomphalariaalexandrinathe host snail of Schistosomamansonai, a worm that causes bilharziasis.The acetone sol. fraction showed a LC50 value of 35.00 ppm. Whereas, the acetone insol. fraction showed a LC50 value of 17.67 ppm,which is far below the WHO standard of toxicity that requiresthe LC50value of the tested material to be less than 100.00 ppm. Also the biocidal activity of both fractions was evaluated on cercaria and meracidia ofSchistosomamansonaiand they exhibited potent miracidicidal and cercaricidal activity, causing 100% mortality in meracidia just after 15 min of treatment and 100 % mortality in cercaria after 1h of treatment. Part II: Phytochemical investigation of the 80% aqueous methanol leaf extract of Albizia anthelmintica Family Fabaceae This includes: 1-Preliminary phytochemical screening of the 80% aqueous methanol leaf extract of Albizia anthelmintica. 2-Fractionation, isolation, and purification of compounds obtained from the acetone insol. fractionand their identification using 1H-NMR, APT, HSQC, HMBC, COSY, and HRESIMS. The phytochemical study of Albizia anthelmintica included successive column chromatographic fractionation of the acetone insol. fraction, separation of individual compounds, and establishment of their purity by TLC. Nuclear magnetic resonance spectroscopic analytical techniques and high resolution electron spray ionization mass spectrometry were extensively applied in this thesis, to identify the chemical structure of the isolated compounds.