Stilbenes from Veratrum maackii Regel protect against ethanol-induced DNA damage in mouse cerebellum and cerebral cortex

Ethanol is a principle ingredient of alcoholic beverages with potential neurotoxicity and genotoxicity, and the ethanol-associated oxidative DNA damage in the central nervous system is well documented. Natural source compounds may offer new options to protect the brain against ethanol-induced genotoxicity. Veratrum maackii Regel is a toxic rangeland plant linked to teratogenicity which is also used in traditional Chinese medicine as 'Lilu' and is reported to contain a family of compounds called stilbenes that can have positive biological activity. In this study, nine stilbenes were isolated from the aerial parts of V. maackii Regel and their structures were identified as cis-mulberroside A (1), resveratrol-4, 3′-O-β-D-diglucopyranoside (2), mulberroside A (3), gentifolin K (4), resveratrol-3, 5-O-β- D-diglucopyranoside (5), oxyresveratrol- 4'-O-β-D-glucopyranoside (6), oxyresveratrol-3-O- β-D -glucopyranoside (7), oxyresveratrol (8) and resveratrol (9) using ESI-MS and NMR techniques. The total concentration of extracted compounds 2-9 was 2.04 mg/g, suggesting that V. maackii Regel is a novel viable source of these compounds. In an in vivo comet assay, compounds 1∼9 were observed to decrease the DNA damage in mouse cerebellum and cerebral cortex caused by acute ethanol administration. Histological observation also revealed decreased brain injury in mice administered with compounds 1~9 after acute ethanol administration. The protective effects of compound 6 were associated with increasing T-SOD and GSH-PX activities and a decrease in NO and MDA concentrations. These findings suggest that these compounds are potent inhibitors of ethanol-induced brain injury possibly via the inhibition of oxidative stress and may be valuable leads for future therapeutic development.