Cytotoxic effects of three Persian Gulf species of Holothurians

Background: Pharmaceutical industries around the world are struggling for finding new approaches to fight cancer and many researchers are involved in this process to find new drug candidates. Aims: The current study aimed at investigating the new marine natural products with anticancer potential from the three Persian Gulf Holothuria sea cucumbers. Methods: We evaluated the cytotox activity of different organs of three Holothuria sea cucumbers species (H. scabra, H. parva, and H. leucospilota) using organic extract (OE): nHexane (nH), ethyl acetate (E), and methanol (M). Cytotoxicity potential of three fractions was estimated using two toxicity models: brine shrimp (Artemia salina) lethality assay (BSA) and tetrazoliumbased colorimetric assay (MTT) assay in human cancer cell lines (MCF7( and normal cell lines (HeLa). Results: The data illustrated that toxicity depends on concentration but BSA was highest for the M extracts of cuvierian tubules (CT) organs of H. leucospilota (up to 95% at 1000 µg/ml, LC50 = 616.4 μg/ml) and respiratory tree (RT) organs of H. parva (up to 86% at 1000 µg/ml, LC50 = 607.2 μg/ml). Based on cell lines, the more effective extracts were noticed for E fractions of CT organs of H. leucospilota (up to 85% at 250 µg/ml, LC50 = 37.25 μg/ml) against MCF7 and for E extracts of intestine tract (IT) organs of H. parva (up to 80% at 250 µg/ml, LC50 = 46.25 μg/ml) against HeLa cells. This variation indicates that the possible cytotoxic compounds in fractions are selective toxicity toward cell lines. Conclusion: The data demonstrated that Holothuria species are an interesting source for discovery of drugs.