Endothelial dysfunction along with an increase in reactive oxygen species observed in 2-kidneys-1-clip (2K1C) hypertensive rats escalates hypertension. This study aimed to investigate the vasorelaxant effect of camboginol from Garcinia dulcis which is a robust antioxidant in normotensive and 2K1C hypertensive rats (n=6, each). Intravenous injection of camboginol showed a transient reduction in arterial blood pressure and restored both the impaired baroreflex sensitivity and the elevated plasma malondialdehyde observed in the 2K1C rat model. Experiments in isolated thoracic aorta revealed the vasorelaxant action of camboginol with pD2 of 9.67±0.19 and 8.01±0.66 in normotensive and 2K1C hypertensive rats, respectively. The mechanisms of its actions involved the different extent of endothelial nitric oxide and prostacyclin signaling pathway and opening of the ATP-activated potassium channel. Camboginol also enhanced an endothelial nitric oxide synthase expression in the isolated vessel from 2K1C rats. It is concluded that vasorelaxant mechanisms of camboginol may involve its antioxidant activity.
