Abstract

Problem statement: Bauhinia tomentosa is a medicinal plant popularly used as herbal remedy for various ailments in Ayurveda. However, the scientific basis for its medicinal use especially in pain and inflammation remains unknown. Therefore, the present study was designed to evaluate analgesic and antioxidant potential of the ethanol, methanol and aqueous extract of Bauhinia tomentosa (stem).

Approach: The analgesic activity was determined for its central and peripheral pharmacological actions using Eddy’s hot plate method and acetic acid-induced writhing test in mice respectively. The ethanol, methanol and aqueous extracts were also investigated for its antioxidant potential through 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and Nitric Oxide (NO) scavenging assays.

Results: Methanol and aqueous extract at the doses 200, 400 mg/kg and ethanol extract at high dose (400 mg/kg) significantly (p<0.05) inhibited number of writhing as well as increase in mean latency time. The ethanol extract at low dose (200 mg/kg) showed centrally anti-nociceptive effect but not peripherally. In acetic acid-induced writhing test, the ethanol, aqueous and methanol extract at the dose of 400 mg/kg produced a maximum of 81.21%, 79.18% and 72.5 % inhibition whereas reference drug Indomethacin showed a maximum inhibition of 79.26 % respectively. A dose dependent scavenging of DPPH radical scavenging has been observed with IC₅₀ values of the methanol, ethanol and aqueous extracts were found to be 65.50, 167.4 & 85.85 µg/ml whereas the IC₅₀ value for the reference ascorbic acid was 52.34 µg/ml. Extracts were also found to possess good nitric oxide scavenging potential with IC₅₀ value of 220.43, 150.45 and 310.25 µg/ml of ethanol, methanol and aqueous extracts while IC₅₀ value of standard ascorbic acid was found to be the 125.10 µg/ml respectively.

Keywords: Anti-nociceptive, acetic acid induced writhings, Bauhinia tomentosa, DPPH, Eddy’s hot plate method, nitric oxide scavenging potential.