Evaluation of antibacterial, antifungal and cytotoxic effects of Holothuria scabra from the North Coast of the Persian Gulf

Summary Bioactive compounds of the gonad, respiration tree, and body wall of the sea cucumber Holothuria scabra collected from the North Coast of the Persian Gulf were extracted using ethyl acetate, methanol and water–methanol mixtures. Extracts were evaluated for their antibacterial and antifungal activities against Aspergillus niger , Candida albicans , Staphylococcus aureus , Pseudomonas aeruginosa and Escherichia coli . The activity was determined using the disc diffusion test. Cytotoxic activities of the extracts were determined by brine shrimp lethality assay. Results showed the existence of an antifungal activity of all extracts against A. niger with MIC ranging from 3 to 9 μg/mL. The highest antifungal activity was found in respiration tree (methanol) with an inhibition zone of about 50 mm against A. niger at 18 μg/mL extract concentration. Cytotoxic activity was obtained for methanolic extracts only. Methanol extract of the gonads showed the highest cytotoxic effect (LC 50  = 50.5 μg/mL) continuing with RT methanol extract (LC 50  = 70 μg/mL).