Nootkatone from the rhizomes of Cyperus rotundus protects against ischemia-reperfusion mediated acute myocardial injury in the rat

Abstract

Background and Objective: The up-regulation of heme oxygenase-1 (HO-1) has been reported to protect from ischemia-reperfusion (I/R) injury and nootkatone, a pharmacologically active ingredient found in the rhizomes of Cyperus rotundus has been reported to induce HO-1 in immune cells. The aim of the present study was to determine whether the protective effect of C. rotundus extract and its constituent, nootkatone against myocardial I/R injury is due to its antioxidant and anti-inflammatory effects. Materials and Methods: Nootkatone was isolated from the rhizomes of Cyperus rotundus using chromatographic techniques. The concentration of nootkatone in the extract was analyzed by HPLC to be 0.254±0.155 μg mg–1. Adult male rats were subjected to 30 min of ischemia and 24 h of reperfusion. Rats were randomized to receive vehicle, extract (10 mg kg–1) or nootkatone (5 or 10 mg kg–1) 1 h before reperfusion. Infarct sizes were measured and myocardial functions assessed. Results: Nootkatone and the extract of C. rotundus at 10 mg kg–1 significantly ameliorated I/R-induced myocardial dysfunction by increasing the first derivative (±dp/dt) of left ventricular pressure and decreasing infarct size. Conclusion: The present study suggests that the extract of C. rotundus rhizomes and its active ingredient, nootkatone protect heart from I/R injury by reducing oxidative stress and the expressions of inflammatory mediators by HO-1 induction.