Antibacterial and cytotoxic activities of four selected summer season fruits' seeds of Bangladesh

The seeds of fruits which are thrown away as waste can be used in medicinal and therapeutic purposes. The goal of this investigation was to find out antibacterial and cytotoxic potentialities of crude acetone and ethanol extracts of seeds of four common summer fruits, purchased from Khulna region, Bangladesh: Litchi chinensis (Lychee), Phoenix dactylifera (Date Palm), Syzigum cumini (Black Plum) and Artocarpus heterophyllus (Jackfruit). Extracts were screened for their antibacterial activity by agar well diffusion method, followed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination by colorimetric broth macro dilution method and plating method. The highest antibacterial activity was found from acetone extract of S. cumini against Salmonella typhi where zone of inhibition was 19.67±0.27 mm along with MIC 0.0585 mg/ml and MBC 0.2344 mg/ml. Acetone extract of S. cumini was found to have bactericidal effect on all microorganisms except bacteriostatic on E. coli and S. paratyphi and ethanol extract showed bactericidal effect on all the microorganisms tested. The cytotoxic activity was determined by brine shrimp lethality assay. Among all seed samples, P. dactylifera exerted relatively better cytotoxicity where LC50 value was below 100 μg/ml. The rest of the samples showed relatively less toxicity as LC50 value was more than 100 μg/ml. Among all the seed samples, S. cumini showed most potential antibacterial activity with less cytotoxicity. Overall, the findings of the study endorse antibacterial activity of examined seed extracts with moderate cytotoxic activity, suggesting the isolation of active compounds thorough bioassays.