Acute toxicity study and anti-nociceptive activity of Bauhinia acuminata Linn. leaf extracts in experimental animal models

Bauhinia acuminata commonly known as dwarf white orchid tree is traditionally used to treat acute and chronic pain, skin ailments, cancer, diabetes, throat infections and asthma. As there were no scientific reports on use of Bauhinia acuminata for anti-nociceptive activity, the present study was designed to evaluate possible effects of aqueous and alcoholic extracts in experimentally induced pain in animals. Acute toxicity was carried out as per OECD guideline 423. The anti-nociceptive activity was evaluated in Swiss albino mice by hot plate, acetic acid induced writhing and tail immersion tests at three different dose levels (250, 500 and 1000 mg/kg) of aqueous and alcoholic extracts. Formalin induced nociception test was performed in Sprague Dawley rats at three dose levels. Both aqueous and alcoholic extracts were found safe at dose of 5000 mg/kg. In hot plate test, both extracts showed significant (p < 0.001) anti-nociceptive activity. In acetic acid writhing test, both aqueous and alcoholic extracts significantly reduced number of writhes (p < 0.001). In Tail immersion test, both the extracts showed significant increase in tail withdrawal response (p < 0.001). Treatment with aqueous and alcoholic extracts significantly reduced nociception in formalin induced nociception model (p < 0.001). From the results it can be concluded that aqueous and alcoholic extracts possesses potent anti-nociceptive activity.