Abstract
Chemical constituents, antioxidant activities and cytotoxic effects of the 70% aqueous ethanolic extract of Brassica rapa L.(six fractions F1-6) of (BRE) were investigated. Its chromatographic, chemical and spectral analysis detected the existence of a new natural isorhamnetin glycosides namely; isorhamnetin 3-O-β-D-glucopyranosyl(1→2)-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside (L2) together with fifteen known flavonoid compounds; five of the type kaempferol glycosides, four of quercetin glycosides, three of isorhamnetin glycosides and three aglycones. Silver nanoparticles of the ethanolic extract were also prepared which gave nanoparticles less than 20 nm.The two extracts (ethanolic extract and its nanoparticles) were evaluated for their potential cytotoxicity and as an antioxidant which showed that, the highest antioxidant extract was NBRE followed by BRE. The BRE and its NBRE were evaluated against HELA cells (human Cervical cancer cell line) and M-NFS-60 cells (human Mouse Myelogenous Leukemia carcinoma) with Doxorubicin as standard drug which NBRE gave high activity for both two cell line.