Protective effects of several components of Gastrodia elata on lipid peroxidation in gerbil brain homogenates

Gastrodia elata (GE) Blume, a traditional herbal agent, has been used mainly in anticonvulsive treatment in Asia. Recently, extracts of GE were evaluated for their potential as neuroprotectives and antioxidants. This study was designed to examine the antioxidant effect of the ether fraction of the methanol extract (EFME) of GE along with its major constituents vanillin, vanillyl alcohol, hydroxybenzaldehyde and hydroxybenzyl alcohol. In experiment 1, gerbils were treated with EFME of GE at a dosage of 500 mg/kg/day for 2 weeks. Oxidative stress was induced with H₂O₂ or ferrous ion, and lipid peroxidation was measured. In experiment 2, oxidative stress was induced with various concentrations of H₂O₂ or ferrous ammonium sulfate, and lipid peroxidation was measured. To compare the antioxidant potency, the inhibitory concentration 50% (IC₅₀) was determined. EFME of GE reduced auto-peroxidation and H₂O₂-induced lipid peroxidation. However, it did not significantly reduce ferrous ammonium sulfate-induced lipid peroxidation. The order of antioxidation potency was as follows: hydroxybenzyl alcohol > vanillyl alcohol > vanillin > hydroxybenzaldehyde. In the case of hydroxybenzaldehyde, its antioxidant effect was more potent than that of melatonin. The excellent antioxidant effects of GE and its main constituents may have potential in the treatment of lipid peroxidation-associated neurological disease. Copyright © 2007 John Wiley & Sons, Ltd.