Novel strain of Nocardiopsis sp. CN2 from andaman nicobar islands: Isolation, taxonomy, fermentation, and antiproliferative effect on cervical cancer cells

Abstract

Background: Cancer continues to be one of the world's deadliest diseases. New antibiotics with unique modes of action are urgently needed and therefore extensive research has been undertaken on novel anti-cancer antibiotics from natural resources. The aim of this present study was undertaken to characterize the marine actinobacterial strain CN2 isolated from Andaman and Nicobar Islands and also to evaluate its antiproliferative activity on HeLa cervical cancer cell line. Methods: Antiproliferative effect of the ethyl acetate extract was evaluated on HeLa cell lines by MTT assay and the oxidative stress was determined by lipid peroxidation and glutathione reductase changes in the antioxidant status. To understand the mode of antiproliferative effect, intracellular ROS levels by DCFH-DA method, mitochondrial membrane potential alterations by Rh-123 staining, oxidative DNA damage by comet assay, and apoptotic morphological changes by AO/EtBr-staining method were studied. Results: Based on the studied phenotypic, chemotaxonomic and molecular characteristics, strain CN2 was identified as Nocardiopsis sp. and it showed 99.9% similarity with N. exhalans (EU570349). However differences observed in certain phenotypic properties between strain CN2 and its close related species N. exhalans evidenced its novelty at strain level. Actinobacterial extract enhanced the ROS level, as evidenced by the increased DCF fluorescence. Further, it altered the mitochondrial membrane potential and increased the oxidative DNA damage and apoptotic morphological changes in HeLa cell lines. Conclusion: This is the first report on antiproliferative activity of the rare actinobacterium, Nocardiopsis sp. from Andaman and Nicobar Islands. Further production, purification and characterization of active metabolite from the ethyl acetate extract will pave the way for promising anticancer drug development.