Abstract

The present study was aimed to investigate the antihypertensive and antioxidant potential of borneol - a natural terpene, against Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) induced hypertension in rats. Hypertension was induced in adult male albino rats of the Wistar strain, weighing 180-220 g, by oral administration of the L-NAME (40 mg/kg bw/day) in drinking water for 4 weeks. Rats were treated with borneol (50 mg/kg bw/day) for 4 weeks. Systolic and diastolic blood pressure was measured every week and the toxic effect of L-NAME was determined using lipid peroxidative markers (thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH). We assessed the activity of enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and measured the levels of non-enzymatic antioxidants (vitamin C, vitamin E and reduced glutathione            (GSH)) levels in erythrocytes, plasma and tissues. Our results showed that oral administration of borneol (50 mg/kg bw/day) significantly attenuated systolic and diastolic blood pressure. In addition, borneol significantly reduced lipid peroxidation and increased the activities and level of enzymatic and non-enzymatic antioxidants. These results were supported by histopathalogical studies. The effect of borneol was comparable with nifedipine. These findings suggest that borneol affords a significant antihypertensive and antioxidant effect against L-NAME induced hypertensive rats.