Luthfun Nesa - Department of Pharmacy, Atish Dipankar University of Science and Technology, Dhaka, Bangladesh
Shirajum Munira - Department of Pharmacy, Atish Dipankar University of Science and Technology, Dhaka, Bangladesh
Shabnam Mollika - Department of Pharmacy, Atish Dipankar University of Science and Technology, Dhaka, Bangladesh
Md. Monirul Islam - Department of Pharmacy, Atish Dipankar University of Science and Technology, Dhaka, Bangladesh

Objectives: The study was carried out to assess the analgesic, anti-inflammatory, and CNS depressant activity of the methanolic extract of  the Lawsonia inermis barks(MELIB). Materials and Methods: Anti-inflammatory effects of MEBLI were studied using carrageenan-induced inflammatory method at the dose of 300 and 500 mg/kg b.wt., p.o. Analgesic activity was measured using acetic acid-induced writhing model and formalin-induced licking and biting in mice. The CNS depressant activity was evaluated by observing the reduction of locomotor and exploratory activities in the open field and hole cross tests at a dose of 300 and 500 mg/kg body weight. Results: Statistical analysis showed that dose  of 500 mg/kg  exhibited higher analgesic activity against acetic acid-induced pain in mice than the standard drug diclofenac sodium. Furthermore, doses of 300 and 500 mg/kg caused higher percent of protection (91.16% and 95.03%, respectively) of licking and biting of formalin-induced mice than diclophenac sodium (70.72%). The Lawsonia inemis methanolic extract (300 and 500 mg/kg) alsoexhibited sustained inhibition (54.97% and 65.56%) of paw edema at the 4th hour compared with standard indomethacin (74.17%). Besides, the plant extract also had significant (p<0.05) dose-dependent CNS depressant activity. Conclusion: this study recommends that the methanolic extract of  Lawsonia inermis barks has significant analgesic, anti-inflammatory, and CNS depressant properties.

Analgesic, Anti-inflammatory, Carrageenan, CNS depressant, Formalin induced pain Methanolic, extract of Lawsonia inermis barks, Writhing