Antimicrobial and Cytotoxic activities of Ascidian Species Collected from Egyptian Coasts

Abstract

Discovering novel drugs for curing cancer and infectious diseases is the prime interest of several research areas now. Marine sessile invertebrates have produced secondary metabolites, a lot of which are utilized as novel pharmaceutical agents with diverse effects whether anti-cancer or anti-microbial. Ascidians are marine sessile animals (phylum: Chordata, class: Ascidiacea). Various anti-cancer, anti-viral, and anti-bacterial components are obtained from different bioactive compounds belonging to ascidian species and are in different stages of clinical trials. In this study, five ascidian species which are Polyclinum constellatum, Botryllus eilatensis, Didemnum sp., Symplegma rubra, and Styela canopus were collected from two coastal sites in Egypt. These specimens were utilized for preparing extracts using organic and inorganic solutions. Crystal violet assay using human breast cancer cell line was performed for evaluation cytotoxic activity of dried extracts, besides the diffusion agar technique to assess anti-microbial activity using 6-type fungi: Aspergillus fumigatus, Aspergillus flavus, Candida albicans, Syncephalastrum racemosum, Candida tropicalis, and Penicillium expansum, Gram-positive Bacteria: Staphylococcus aureus, Bacillus subtilis, and Streptococcus mutants, and Gram-negative bacteria: Enterobacter cloacae, Escherichia coli, and Proteus vulgaris. Two ascidian species, Didemnum sp. and S. rubra, showed significant cytotoxicity against human breast cancer cell line while other species showed moderate cytotoxicity. All investigated ascidian species have antibacterial compounds toward S. aureus and B. subtilis. The only species exhibited antibacterial activity against the fungus A. fumigatus was Botryllus eilatensis Didemnum sp. has exhibited activity against seven microbes, while S. canopus, Botryllus eilatensis, S. rubra, and P. constellatum have exhibited activities against 4,5,4, & 2 microbes from twelve used microbes, respectively. Therefore, ascidian species are excellent species for further studies to discover new pharmaceutical agents in Egypt.