Evaluation of analgesic activity of methanolic extract of bougainvillea spectabilis leaves in experimental animal models

Abstract

Background: Anti-inflammatory activity of leaves of Bougainvillea spectabilis (family Nyctaginaceae) has already been demonstrated in experimental animals. As pain is one of the important components of inflammation, we had set forward a study this find out possible analgesic activity of the same in animal models Objective: Evaluation of analgesic effects of, Bougainvillea spectabilis in mice models. Methods: 215 gm of fresh dried leaves of Bougainvillea spectabilis (BS) were collected from the local area during the flowering season and air dried. Following Methanol extraction, under reduced pressure solvent was removed on a rotary evaporator. The lyophilized extract was collected and the yield was 8 gm. That was used as an emulsion prepared in propylene glycol and orally administered (20 and 50 mg/kg). Central and peripheral analgesic activities of Bougainvillea spectabilis (BS) were evaluated by tail flick, tail immersion test and writhing test (acetic acid induced) respectively. Study Design: This is an experimental study designed on animal models. Results: Bougainvillea spectabilis (BS) had shown no analgesic action in central anal gesic model at different hours as the reaction time was less than 10 seconds at all time interval. With regard to peripheral analgesic activity, maximal activity was observed at 50 mg/kg b.w. The mean writhes ± standard deviation were 42.7±0.9 and 40±0.5 respectively in BS (20 mg/kg) and BS (50 mg/kg) in comparison to standard drug aspirin (33.3±0.4), control mice being 55.3±0.4. Conclusion: Our data indicates that Bougainvillea spectabilis (50 mg/kg) has a significant peripheral analgesic activity. Without isolating the active principles it's extremely difficult to pinpoint the mechanisms contributing to the observed analgesic activities of Bougainvillea spectabilis and extrapolate that in clinical practice.