New polyacetylenes from Echinophora cinerea (Boiss.) Hedge et Lamond.

Echinophora cinerea aerial parts are used in folk medicine to cure gastric diseases and as a food seasoning in cheese and yogurt. Besides several pharmacological effects have been assigned to Echinophora spp., there is no phytochemical investigation on this genus other than our previous publication on flavonoids. An acetone extract of E. cinerea afforded three new (1-3) polyacetylenes, one rare monoterpenoid glycoside as verbenone-5-O-ß-D-glycopyranoside (4) and one prenylated coumarin as osthol (5). The structures of all new compounds were elucidated using modern spectroscopic methods, including 2D NMR and mass analyses. The potency of the compounds to induce cell death was determined on SKNMC, PC3 and MCF-7 cell lines using MTT method in which compounds 1 and 2 showed moderate cytotoxic effects, especially against PC3 cells.

Quercetin-3-O-ß-D-glucopyranoside, a dietary flavonoid, protects PC12 cells from H2O2-induced cytotoxicity through inhibition of reactive oxygen species.

Since flavonols are antioxidant agents, they could in principle, beneficially affect neurodegenerative diseases where reactive oxygen species are involved. Quercetin derivatives are the most abundant dietary flavonoids, and we have investigated the capacity of quercetin-3-O-ß-d-glucopyranoside (Q3G) isolated from Echinophora cinerea to protect PC12 cells from H2O2-induced cytotoxicity. Direct cytotoxic effects of H2O2 on PC12 in presence and absence of Q3G were evaluated. H2O2 induced cytotoxicity in a concentration dependent manner (IC50=118 ± 5.09 µM, 24h). Pretreatment of cells with non-toxic concentrations of Q3G protected cells from H2O2-induced cytotoxicity, leading to a decrease in the generation of reactive oxygen species. These observations qualify Q3G as an interesting dietary compound worth further investigation as a cytoprotective agent.