Vasoprotection by melatonin and quercetin in rats treated with cisplatin.

Cisplatin-based chemotherapy has a variety of vascular side effects. The aim of the present study was to evaluate the beneficial effect of melatonin and cisplatin on the alterations in vascular reactivity and structure of cisplatin-treated rats. Phenylephrine (PHE) and KCl-caused concentration-dependent contractions of rat aorta. Pretreatment with cisplatin increased the sensitivity but not the max response to PHE and KCl. In rats treated with melatonin or quercetin before cisplatin, the EC50 values, but not the maximal response to both agents were significantly higher than cisplatin-treated group. Compared to the control group, cisplatin-treatment significantly reduced the luminal area of the aorta. In melatonin and quercetin-treated aortas the luminal area values were significantly higher than cisplatin-treated group. The results demonstrate for the first time that melatonin and quercetin treatment may protect the aorta in cisplatin-based chemotherapy.