Evaluation of antioxidative, analgesic and anti-inflammatory activities of methanolic extract of Myrica nagi leaves - an animal model approach

Myrica nagi (family Myricaceae) is commonly known as Kathphal (Hindi) and Bayberry (English) and it has a long history of usage in traditional medicine. It is popular actinorhizal plant for its symbiotic relationship with Frankia. This study was taken in force to estimate the analgesic, anti-inflammatory and anti-oxidative activities of methanolic extract of Myrica nagi (MMN) in an animal model. Anti-oxidative property of MMN was assessed by free radical scavenging assay (DPPH method). The acute toxicity test of methanolic extract of MMN revealed that the median lethal dose (LD50) was found to be 2080 mg/kg body weight in mice. The anti-inflammatory property was evaluated by carrageenan-induced acute inflammation in rats by measuring rat paw volume at different time intervals and toxicological analysis using mice. The analgesic effect was measured in Wistar rats using the acetic acid-induced writhing test and MMN at 200 mg/kg BW showed 54.56 % inhibition of writhing. MMN showed higher anti-oxidant activity in DPPH assays as compared to standard. High dose of MMN showed a significant reduction (21.71 %) in inflammation after 4 h of treatment, which was comparable to diclofenac (10 mg/kg BW; 32.75 %)-treated group. Significant reduction (p < 0.05) in the levels of inflammatory cytokine (IL-1β and TNF-α) markers were also observed in serum of MMN-treated animals as compared to control. Taken together, the phenolic compounds of MMN may serve as potential herbal drug for amelioration of acute inflammation due to their modulatory action on free radicals.