Phytochemical Screening and Pharmacological Evaluation of <i>Bruguiera gymnorhiza</i> Methanolic Leaf Extract

<i>Bruguiera gymnorhiza</i> (Rhizophoraceae) is an indigenous mangrove plant with a salient history of traditional uses. This study aimed to explore the phytoconstituents and biological responses of its methanolic (95%) leaf extract (ME). The initial phytochemical screening indicated the presence of alkaloids, carbohydrates, saponins, phenols, and flavonoids. Then, the anthelmintic and antioxidant capabilities were evaluated against <i>Pheretima posthuma</i> (earthworms), DPPH (0.004%), and ABTS cation radical solutions, respectively. Afterward, cardioprotective and hepatoprotective responses were studied in cyclophosphamide-induced myocardial damage and paracetamol-intoxicated liver cirrhosis. The anthelmintic study revealed that ME (50 mg mL⁻¹) had a lower potency (7.45 min) than albendazole (3.63 min) in killing parasites. Furthermore, it exhibited a dose-dependent efficacy (IC₅₀ 50.297 and 55.126 µg mL⁻¹) against free radicals in both DPPH and ABTS assay, although less effective than the ascorbic acid (IC₅₀ 24.177 and 23.61 µg mL⁻¹). The elevated serum levels of cardiotoxicity indicators (aspartate aminotransferase, lactate dehydrogenase, creatine kinase, troponin-I, and lipid profiles) declined by the extract (300 mg kg⁻¹ body weight). Moreover, at a similar dose, it reduced the high circulatory biomarkers (alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, and total bilirubin) levels of hepatocyte injury. This study recommends promising pharmacological values of <i>Bruguiera gymnorhiza</i> ME.