Anti-Nociceptive and Anti-Inflammatory Potential of Stem Bark Fractions of Dalbergia candenatensis (Dennst.) Prain: Insights from Experimental Models into Underlying Mechanisms

Abstract

Dalbergia candenatensis (Dennst.) Prain (family: Fabaceae), a mangrove species with traditional medicinal use, was evaluated for its phytochemical composition and the in vivo anti-nociceptive and anti-inflammatory effects of its stem bark fractions in Swiss albino mice. Acute toxicity was studied at doses up to 2000 mg/kg body weight (b.wt.) and animals were observed for 14 days. Anti-nociceptive activity was evaluated using acetic acid-induced writhing (chemically induced pain), formalin-induced paw licking (neurogenic and inflammatory pain), tail immersion, and hot plate methods (thermally induced pain). Anti-inflammatory activity was evaluated in carrageenan and formalin-induced paw edema models. Results showed that mice exhibited no mortality or noticeable behavioral alterations at doses up to 2000 mg/kg b.wt. during the 14 days observation period. In comparison to control, all fractions at 200 mg/kg b.wt. showed significant (p < 0.001) anti-nociceptive activity. The n-hexane fraction produced the highest inhibition (50.86%) in the acetic acid test. In the formalin test, the ethyl acetate fraction exhibited maximum inhibition (59.69% in the early phase and 48.00% in the late phase). In the tail immersion and hot plate methods, ethyl acetate and dichloromethane fractions produced significant (p < 0.001) increases in reaction time compared with standard drugs. In the anti-inflammatory assays, the ethyl acetate fraction showed maximum inhibition of paw edema in both carrageenan (47.37%) and formalin (51.30%) models. The results suggest that stem bark fractions of D. candenatensis possess significant (p < 0.001) anti-nociceptive and anti-inflammatory activity, possibly mediated by both central and peripheral mechanisms.