Effects of Verapamil and Nifedipine on Carrageenan-induced inflammation in the rat paw

Abstract: The extracardiac actions of calcium-channel blockers has little been studied. In fact, it has been demonstrated in a number of in vitro studies, that calcium-channel blockers are involved in inflammation. Here, we evaluated the dose-dependent effects of he verapamil and Nifedipine on carrageenan-induced, acute inflammation in the rat paw compared to the anti-inflammatory activities of ibuprofen. The adult male rats were divided into two groups. Paw edema was induced by intraplantar injection of 0.1 ml of 0.5% carrageenan solution. Different doses of nifedipine (10, 25, 100, 200 µg/kg) and verapamil (25, 100, 400 µg/kg) and ibuprofen 12 mg/kg given intrapritoneally after carrageenan injection. Assessment of edema performed by calculation of volume changes and by extravasation of Evans Blue in test group compared to the control, one hour after injection of carrageen. Verapamil and nifedipine showed significantly inhibitory effect on increased edema. Maximum inhibition (83±10%) were induced by nifedipine at 100 µg/kg and verapamil at 25 µg/kg. Nifedipine inhibited paw edema in a dose-dependent manner. The inflammation was significantly reduced (37±5.2%) by nifedipine at 200 µg/kg, whereas verapamil did not have any effect. Ibuprofen reduced increased volume of paw and Evans Blue content by 83±11.5%, and 42±6.3% respectively. No significant differences were found between inhibitory effects of nifedipine and ibuprofen. According to this results, calcium-channel blockers can inhibit acute inflammatory responses in the paw, and these effects are comparable to ibuoprofen. Keywords: Verapamil, Nifedipine, Acute inflammation, Calcium channels blocker