Abstract

The methanolic root extract of Cissus quadrangularis L. (CQ) belongs to the family Vitaceae and was evaluated for its antinociceptive activity by radiant heat and acetic acid induced pain models in mice, at four different dose levels of 10, 50, 100 and 200 mg/kg by intraperitoneal (i.p.) route. The results obtained in the writhing test showed that CQ at a dose levels of 50, 100, 200 mg/kg significantly inhibited the acetic acid-induced writhing in mice in a dose dependant manner decreasing the writhes by 84.23% at a dose of 200 mg/kg. In the tail-flick assay, the results obtained with the intraperitoneal administration of CQ at dose levels of 50, 100, 200 mg/kg i.p. demonstrated significant antinociceptive activity increasing the latency of tail flick in mice comparable to the control drug, pentazocine (10 mg/kg i.p.). The intraperitoneal administration of naloxone along with CQ decreased the latency of tail flick in mice, which suggest that CQ contain antinociceptive substances which appear to be related to the activation of opioid receptors. The results showed that the methanolic extract of C. quadrangularis L. had excellent antinociceptive activity.

Key words: Cissus quadrangularis, antinociceptive, spinal algesia.