Identification and anti-cancer activity in 2D and 3D cell culture evaluation of an Iranian isolated marine microalgae Picochlorum sp. RCC486.

PURPOSE: Cancer disease is the second cause of death in the world. Now a days, high percentage of drugs, which are involved in treatment of cancers, have natural origin. Introduction of microalgae strains as anti-cancer drugs origin is a valuable approach for cancer therapy.

METHODS: In the present study we describe the isolation, characterization, and anti-proliferative activity of a new microalga strain (Picochlorum sp. RCC486) from Iran. The cytotoxic activity of four different algal extracts including methanol, ethyl acetate, chloroform, and hexane were evaluated against MDA-MB-231, MCF-7, Hep-G2, and A-549 cell liens. Cell viability was determined using MTT assay in both monolayer and spheroids 3D cultures. The apoptosis was confirmed by different methods such as AO/EB and Annexin V-FITC/PI double staining, caspase-3 colorimetric assay, ROS and MMP assay.

RESULTS: The results of MTT assay and fluorescent double staining confirmed that methanol and ethyl acetate extracts showed the best cytotoxic activity against the cancer cell lines. The production of ROS, caspase-3 activity and depolarized MMP were quite significant in MDA-MB-231 cell line treated with methanol and ethyl acetate extracts.

CONCLUSION: In this research we revealed that cytotoxicity and apoptotic effects of the methanol and ethyl acetate extracts in human cancer cells make them good candidates for further pharmacological studies to discover effective drugs for cancer therapy. Graphical abstract The present study describes the isolation, characterization, and anti-proliferative activity of different extracts of a new microalga strain (Picochlorum sp. RCC486) from Iran. The antiproliferative and apoptosis inducing activity of ethyl acetate and methanol extracts with high content of phenol and carotenoid make them as good candidates for further pharmacological studies to discover effective drugs for cancer therapy.