Positive Health Online

Abstract

PAPPARELLA and colleagues, Department of Clinical and Experimental Medicine, University of Padova, Via Giustiniani 2, I-35128 Padua, Italy, have found that vitamin C prevents anti-HIV medication-related high blood pressure in rats.

Background

Cardiovascular risk is increased among HIV-infected patients receiving antiretroviral therapy due to the development of high blood pressure and metabolic abnormalities. The aim of this study was to investigate the effects of long-term treatment with zidovudine (AZT) and vitamin C, alone and in combination, on blood pressure and on the chain of events linking oxidative stress to cardiac damage in the rat.

Methodology

In this animal study, 6 adult rats received AZT (1 mg/ml) in the drinking water for 8 months, 6 vitamin C (10 g/kg of food) and AZT, 6 vitamin C alone, and 6 served as controls.

Results

AZT increased systolic blood pressure, expression of gp91(phox) and p47(phox) subunits of NAD(P)H oxidase, and protein kinase C (PKC) delta activation and reduced antioxidant power of plasma and cardiac homogenates. AZT also caused morphological alterations in cardiac myocyte mitochondria, indicative of functional damage. All of these effects were prevented by vitamin C.

Conclusion

Chronic AZT administration increases blood pressure and promotes cardiovascular damage through a NAD(P)H oxidase-dependent mechanism that involves PKC delta. Vitamin C antagonizes these adverse effects of AZT in the cardiovascular system.

References

Papparella I et al. Vitamin C prevents zidovudine-induced NAD(P)H oxidase activation and hypertension in the rat. Cardiovascular Research 73 (2): 432-438, Jan 15, 2007.

Comment

Vitamin C is well known for its positive clinical effects upon immunity, collagen, antioxidant activity and heart disease. This study documents how vitamin C can prevent medication-related high blood pressure in rats, caused by AZT.