Anti-Bacterial, Anti-Diarrheal, and Cytotoxic Activities of Edible Fruits in the Sundarbans Mangrove Forest of Bangladesh

This study evaluated anti-bacterial, anti-diarrheal, and cytotoxic activities of ten edible fruits (Aegiceras corniculatum, Avicennia officinalis, Bruguiera gymnorrhiza, Ceriops decandra, Heritiera fomes, Nypa fruticans, Phoenix paludosa, Sarcolobus globosus, Sonneratia caseolaris, and Xylocarpus mekongensis) in the Sundarbans mangrove forest of Bangladesh. Highest antibacterial activity was shown for ethanol:methanol (1:1) extracts of S. caseolaris (2 mg/disc), which demonstrated inhibition zones of 16.7, 17.0, 14.7, 15.7, and 15.7 mm against Escherichia coli, Klebsiella sp., Shigella boydii, Shigella sonnei, and Staphylococcus aureus, respectively. In mice with castor oil-induced diarrhea, S. caseolaris extract (250 mg/kg body weight) showed the highest inhibition (87.7%) and delayed the onset time (273 min) of diarrheal episodes, followed by A. corniculatum extract (inhibition, 83.6%; delayed onset time, 187.4 min). S. caseolaris and A. corniculatum fruit powders were successively fractionated into n-hexane, diethyl ether, chloroform, ethanol, and methanol. Antidiarrheal activity significantly increased with increasing polarity of these fractions. In brine shrimp lethality assay, S. globosus extract demonstrated the highest cytotoxicity (59.2 μg/mL), followed by H. fomes (74.1 μg/mL) and C. decandra (116.7 μg/mL); however, lowest cytotoxicity was shown for A. corniculatum, A. officinalis, and S. caseolaris extracts. Mice treated with A. corniculatum extract did not experience any acute toxicity. These results demonstrate that S. caseolaris and A. corniculatum fruits have potential to treat diarrhea and may act as useful nutraceuticals.