In vivo antioxidant activity of Zataria multiflora Boiss essential oil

Zataria multiflora Boiss. (Lamiaceae) is an endemic plant to Iran with many traditional uses. We have reported previously in vitro antioxidant activity of the essential oil of the plant. In the present work we aimed to evaluate the antioxidant activity of the oil in rat. Antioxidant activity was measured by the test of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical inhibition and inhibition of lipid peroxidation by measuring the index of thiobarbituric acid reactive substances (TBARs). Three doses of 100, 200 and 400 μL/ kg of the essential oil of Z. multiflora (ZMO) was administered to animals by i.g mouth for 10 days. The blood was collected in 11th day through direct puncture and the liver was rapidly excised. The histopathology studies of the animals was compared to animals in butylated hydroxyl toluene (BHT) group. The results showed that ZMO in all tested doses significantly was able to scavenge DPPH radical (P<0.05). ZMO also decreased TBARs in a dose dependent manner. No alteration in LFT enzymes or changes in histopathology of the liver was considered in ZMO treated groups. The results indicated that ZMO might be used in healthy medicine and food industry.