Analgesic and anti-inflammatory activities of the methanolic extract of the rhizomes of Stylochiton lancifolius pyre and Kotchy (Araceae) in rodents

The methanolic extract of the rhizome of Stylochiton lancifolius (50, 100, and 200 mg/kg) was evaluated for analgesic and anti-inflammatory activities using acetic acid-induced writhing, formalin-induced pain and formalin-induced-inflammation. The methanol extract exhibited significant (P < 0.001) inhibition of acetic acid-induced writhing in mice and a significant (P < 0.001) reduction in paw licking time of the second phase of formalin-induced pain in rats. The methanol extract also produced a significant (P < 0.001) anti-inflammatory effect in formalin-induced inflammation which is comparable to that of the reference drug Piroxicam (10 mg/kg), which is a standard analgesic and anti-inflammatory drug. The intraperitoneal (i.p) median lethal dose (LD(50)) of the methanol extract of S. lancifolius was found to be greater than 5000 mg/kg in mice. The result obtained from this study showed that the methanol extract of S. lancifolius possesses analgesic and anti-inflammatory activities and supports the ethnomedical claim of the use of the plant in the management of pain and inflammatory conditions.