Assessment of antioxidant, anti-inflammatory, antimicrobial, antidiarrheal and antipyretic activities of <i>Tamarix dioica</i> stem bark extracts by in vitro and in vivo methods

Introduction: This study evaluated the traditional uses of Tamarix dioica stem bark extracts, with emphasis on antioxidant, anti-inflammatory, antimicrobial, antidiarrheal, and antipyretic activities, using both laboratory- and animal-based experimental approaches, to evaluate its traditional uses. Methods: The methanolic and n-hexane extracts of T. dioica stem bark were analyzed for phytochemical constituents, total phenolic and flavonoid content, and antioxidant activity. Radical scavenging capacity was determined through DPPH and nitric oxide assays using ascorbic acid as a reference standard. Additional evaluations included antimicrobial screening, thrombolytic and membrane stabilization assays, and cytotoxic assessment. Biological activities, including analgesic, antidiarrheal, and antipyretic effects, were examined in Swiss albino male mice at oral doses of 200 and 400 mg/kg body weight. Results: Among the tested extracts, the methanolic fraction demonstrated stronger antioxidant performance than the n-hexane fraction, producing lower IC₅₀ values in both DPPH and nitric oxide scavenging assays (28.91 ± 0.64 µg/mL and 26.24 ± 0.58 µg/mL, respectively). Antimicrobial testing revealed mild inhibitory effects, with the n-hexane fraction producing inhibition zones up to 8 mm against selected bacterial strains and 7 mm against Candida albicans. Both extracts reduced diarrheal frequency, achieved 70.27% inhibition at the higher dose. Pronounced analgesic and antipyretic responses were observed in the n-hexane extract-treated groups, with maximal writhing suppression of 78.43% (P &lt; 0.001) and temperature reduction of 4.4 % (P &lt; 0.001). Conclusion: Stem bark extracts of T. dioica exhibited multiple pharmacological activities, particularly antioxidant, antimicrobial, analgesic, and antidiarrheal effects, confirming its traditional uses. These findings support continued investigation into the isolation and characterization of the active phytochemicals responsible for the observed responses.