Phenolic Content of Albizia anthelmintica Leaves and Their Antioxidant and Cytotoxic Activity

Objectives: This study aimed to the isolate the polyphenolic constituents from the 80% aqueous methanolic extract of Albizia anthelmintica leaves and evaluates the antioxidant and cytotoxic activities of the pure isolates. Methods: 80% MeOH leaves extracts of the plant subjected separately to different chromatographic separation techniques. Structures of the isolated compounds were established by different spectroscopic techniques (ESI-MS, 1H/13C NMR and 2D NMR experiments). The antioxidant activity was evaluated using DPPH scavenging activity method, the crude extracts and pure isolated compounds form active fractions of A. anthelimintica were tested for cytotoxicity against human prostate normal cell line (PNT 2A), human ovarian carcinoma cell line (A2780) and Human Caucasian breast carcinoma cell line (ZR75-1). Results: Nine compounds were isolated from A. anthelmintica four were identified for first time from the plant ferulic acid 2, 3`, 7 di-O-methylmyricetin3, Kaempferol 3-O-(6``-E-p-Coumaroyl)-β-D-glucopyranoside 6 and Kaempferol 3-O-(6``-E-p-Caffeoyl)-β-D-glucopyranoside7and five were isolated before from the plant methyl gallate 1, gallic acid 4, quercetin 5, Quercetin 3-O-(6``-O-galloyl)-β-D-glucopyranoside 8 and Kaemferol 3-O-(6``-O-galloyl)-β-D-glucopyranoside 9. Compounds 8, 9 and 7showed the most powerful anti-oxidant activity among the compounds tested with IC50 2.75, 3.25 and 5.25 μM, respectively. Compounds 7, 3 and 6 showed activity against human ovarian carcinoma cell line (A2780) with IC50 2.6, 5.23and 6.11μM, respectively. Compound 8 showed strong cytotoxic activity against Human Caucasian breast carcinoma cell line (ZR75-1) with IC50 3.15 μM. Conclusion: A. anthelmintica 80% aqueous methanolic leaf extract contains phenolic compounds, some of which were isolated for first time from this species and some have shown strong antioxidant and cytotoxic activity against the tested cell lines. The three active isolated compounds need to be evaluated in animal models to determine their potential as natural cure products.