Comparative Pharmacological Evaluation of Mangrove Plant Xylocarpus mekongensis Pierre and Associated Fungus

Xylocarpus mekongensis commonly known as Poshur, is an evergreen mangrove plant originating from Asia, Indonesia, the Southwestern Pacific Islands, and northern Australia. This study was aimed at compiling information on the comparative pharmacological properties of the methanolic bark extract of X. mekongensis and the fungal endophyte based on their antioxidant, antimicrobial, and cytotoxic activity. The plant extract showed more phenolic (277 mg GAE/g) and flavonoid (140 mg QE/g) content than the fungal extract (45 mg GAE/g and 76 mg QE/g, respectively). The bark extract exhibited better DPPH scavenging capacity (IC50 = 28.27 µg/ml) than endophyte XMSF-I (IC50 = 143.46 µg/ml) extract. Furthermore, we observed that the endophytes associated with this plant showed more significant antimicrobial activity against E. coli, S. aureus, B. subtilis, and A. brasiliensis than its bark extract. In the brine shrimp lethality bioassay, the bark extract and endophyte revealed diminutive lethality (214 and 286 µg/ml, respectively) in comparison with standard vincristine sulfate (0.44 µg/ml). Hence, methanolic bark extract showed more positive reviews than associated fungi.