The present study was undertaken to evaluate the analgesic and anti-inflammatory activity of methanolic and aqueous leaf extracts of Enicostemma littorale. Preliminary phytochemical screening confirmed the presence of alkaloids, flavonoids, phenolics, and tannins in both extracts. Analgesic activity was assessed using the hot plate method and acetic acid-induced writhing test. In the hot plate method, the methanolic extract showed a significant increase in reaction time from 3.2 ± 0.3 s (control) to 7.9 ± 0.5 s at 400 mg/kg, whereas the aqueous extract showed an increase to 6.5 ± 0.4 s. In the acetic acid-induced writhing test, the methanolic extract exhibited 61.3% inhibition at 400 mg/kg, while the aqueous extract showed 50.0% inhibition compared to control (62 ± 3 writhes). Anti-inflammatory activity was evaluated using the carrageenan-induced paw edema model. The methanolic extract demonstrated 56.7% inhibition of paw edema at 400 mg/kg, whereas the aqueous extract showed 43.3% inhibition, compared to control paw volume of 1.20 ± 0.05 mL. The standard drug (diclofenac sodium, 10 mg/kg) showed higher activity with 71.0% inhibition in the writhing test and 62.5% inhibition in the paw edema model. The results indicate that both extracts possess significant analgesic and anti-inflammatory activity, with the methanolic extract showing superior efficacy. The observed activity may be attributed to the higher content of phenolic and flavonoid compounds, which are known to inhibit inflammatory mediators and modulate pain pathways.
Chennu M. M. Prasada Rao1*, Tanniru Rajeswari2, Jyotirmayee Patel2, Renuka Barik2, Rupashree Nishad2, Prakash Pradhan2 (Wed,) studied this question.