Toxicological and cytotoxic evaluation of standardized extracts of Galphimia glauca

Abstract

Galphimia glauca Cav (Malpighiaceae) has been widely used in Mexican traditional medicine as a remedy for the treatment of mental disorders, principally as a sedative and tranquilizer. The sedative activity of extracts obtained from this plant has been demonstrated with different neuropharmacological models. Different triterpenes, known as galphimines, have been identified from the active extract. Galphimine-B (G-B) possesses anxiolytic activity and is able to selectively inhibit discharges of dopaminergic neurons in the ventral tegmental area in rats. Nevertheless, there have been no toxicological investigations carried out with products obtained from this plant. In this work three different extracts (aqueous, ethanolic, and methanolic) of Galphimia glauca, standardized in the content of three galphimines, were evaluated for their behavioral and pharmaco-toxicological effects. After administering the extracts to mice for 28 days (2.5 g/kg, p.o.), no deaths were found and the histopathological analysis of different organs did not show alterations; only the behavioral parameters analyzed showed a diminution of spontaneous activity. The administration of these extracts for 56 days (same doses and route) in mice did not cause any changes in the biochemical parameters that evaluate liver function. On the other hand, no cytotoxic effects were found on KB, UISO, and OVCAR-5 transformed cell lines, but all extracts specifically inhibited colon cancer cell line growth with an ED 50 lower than 2 μg/ml. The extracts were also evaluated in genotoxicity tests in vitro (250, 100 and 50 μg/ml), which demonstrate that none of the three extracts from Galphimia glauca showed a genotoxic effect.