Effect of Intraperitoneally Injection of Different Doses of Simvastatin on Pain and Inflammatory Response Induced by Formalin in Mice

摘要

The 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors (statins) have been unequivocally shown to reduce cardiovascular morbidity and mortality. Their lipid-lowering actions are by reversible and competitive inhibition of the enzyme HMG-CoA reductase, a precursor of cholesterol. It has been suggested that statins appear to have therapeutic benefits in diseases that are unrelated to elevated serum cholesterol levels such as pain and inflammatory. The aim of this study was to determination the effect of intraperitoneally injection of different doses of simvastatin on pain and inflammatory response induced by formalin in mice. Mice were divided into 9 groups randomly, the 1st group received saline normal (ip) (saline group); the 2nd group received Carboxymethylcellulose (CMC) 0.5% (ip) (vehicle group) and the next groups received, respectively different doses of simvastatin (1, 5, 10, 20, 40, 80 and 100 mg/kg/daily) for 4 days (ip) before formalin test. After intrapawly injection of formalin, the time of hind paw biting and licking time measured in 5 min interval for an hour. Results showed that formalin induces biphasic pain response (the 1st phase: 0-5 min and the 2nd phase 15-40 min after injection). Intraperitoneal injection of simvastatin showed significant (p<0.05) decrease of pain responses in the 1st and the 2nd phase in a dose dependently manner. According to the results, simvastatin has analgesic and anti-inflammatory effects on mice. Nevertheless, new studies must be carried out in order to determine the beneficial effects of statins in treatment of pain and inflammatory.