Biflavones of Decussocarpus rospigliosii as phosphodiesterases inhibitors.
ABSTRACT A phytochemical study of an ethyl acetate extract of Decussocarpus rospigliosii leaves led to the isolation of six 3'-8''-biapigenin derivatives identified as amentoflavone (1), podocarpusflavone A (2), sequoiaflavone (3), podocarpusflavone B (4), 7,7''-di-O-methylamentoflavone (5) and heveaflavone (6). Biflavones 1-4 showed strong inhibitory activity on several PDE isoforms. Biflavone (5) showed selective and potent inhibition of the PDE4 isoform (IC50=1.48+/-0.21 microM) and was almost as active as the reference drug Rolipram (IC50=1.1+/-0.2 microM).
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ABSTRACT: The leaves of the Cashew plant (Anacardium occidentale L.) are used by the folk medicine in South America and West Africa. This plant is rich in flavonoids, which are polyphenolic compounds widespread in plants, and that have diverse physiological effects. In a sub-acute toxicity assay it was found that an ethanolic extract of Cashew leaves elicited lymphopenia in rats. The extract was also found to be cytotoxic and to induce apoptosis in Jurkat (acute lymphoblastic leukemia) cells. The crude ethanolic extract was fractionated and resolved by HPLC. One of the four fractions obtained led to the isolation of the biflavonoid agasthisflavone. [(3)H]-thymidine incorporation assays and flow cytometry analysis showed that the isolated compound displayed a high anti-proliferative effect in Jurkat cells with an IC(50) of 2.4 μg/ml (4.45 μM). The effect of agathisflavone on the acute promyelocytic leukemia cell line HL60, Burkitt lymphoma Raji cells and Hep-2 laryngeal carcinoma cells was also tested. The two latter ones were only mildly affected by agathisflavone. It is also shown that agathisflavone induces apoptosis in Jurkat cells and it this proposed that this is the likely mechanism of agathisflavone specific cytotoxicity.Experimental and toxicologic pathology: official journal of the Gesellschaft fur Toxikologische Pathologie 11/2010; 64(5):435-40. · 1.43 Impact Factor