Antinociceptive and Anti-Inflammatory Effects of Solvent Extracts of Tagetes erectus Linn (Asteraceae)

Purpose: Traditionally, the leaves of Tagetes erectus L. are used in India for the alleviation of pain and inflammation. The objective of this study was to investigate the antinociceptive and anti-inflammatory activities of this plant material in an animal model. Methods: The chloroform, methanol and ether extracts of the leaves of Tagetes erectus L. (family: Asteraceae) were tested against acetic acid-induced writhing in mice and carrageenan-induced paw oedema in rats in order to assess their antinoceciptive and anti-inflammatory activities, respectively. The doses administered intraperitoneally (I.P.) ranged from 100 to 400 mg/kg body weight, and acetylsalicylic acid (ASA) and phenylbutazone were the reference standards for the antinoceciptive and anti-inflammatory tests, respectively. Results: The extracts showed antinociceptive and anti-inflammatory properties at doses between 200- 400 mg/kg. They inhibited significantly (P < 0.005), in a dose-dependant manner, induced writhing reflexes in mice. The antinoceciptive effect was comparable to that of ASA which served as the reference standard. Similarly, the extracts significantly (P <0.05) reduced carragenan-induced paw oedema in rats and the reduction in paw volume was comparable to that of the reference standard (phenylbutazone). It also increased pain threshold in the oedematous right hind limb paw of the rats. Conclusion: The results obtained show that the extracts of Tagetes erectus L. (Asteraceae) has antinociceptive and anti-inflammatory properties. This finding provides a basis for the traditional use of the plant material.