In vitro/in vivo antioxidant and hepatoprotective potential of defatted extract and flavonoids isolated from Astragalus spruneri Boiss. (Fabaceae)

The aim of the current study was to evaluate the effect of a defatted extract (EAS) and three flavonoids, isolated from Astragalus spruneri Boiss. (Fabaceae) using in vitro/in vivo models of liver injury. The EAS was characterized by HPLC and flavonoids (14 mg/g dw) and saponins (8 mg/g dw) were proved. The flavonoids (ASF1, ASF3 and ASF5) were isolated from the same extract and partially identified by LC-MS. In in vitro models of non-enzyme induced (Fe2+/AA) lipid peroxidation in isolated liver microsomes and CCl4-induced metabolic bioactivation and t-BuOOH-induced oxidative stress in isolated rat hepatocytes, both EAS and the flavonoids exerted similar to silybin (positive control) an antioxidant and cytoprotective activity, discerned by decreased MDA production in the microsomes and by preserved cell viability and GSH levels as well as by decreased LDH activity and MDA quantity in isolated rat hepatocytes. The antioxidant and hepatoprotective effect of EAS has been confirmed in vivo against CCl4-induced liver injury in rats. EAS restored the GSH levels and the activity of the antioxidant enzymes CAT and SOD, affected by CCl4 administration, as well as decreased the production of MDA. The effect of EAS was commensurable with those of silymarin.