Evaluation of bioactivity and phytochemical screening of endophytic fungi isolated from Ceriops decandra (Griff.) W. Theob, a mangrove plant in Bangladesh

Background Due to increasing number of individuals within the world having health issues caused by varied cancers, drug-resistant microorganism, parasitic protozoans, and fungi could be a cause for alarm. Endophyte’s are a unique source of medicinal compounds which requires an intensive seek for newer and simpler agents to handle these sickness issues is currently advancing. This study explores the description of endophytic fungi of Ceriops decandra (Griff.) W. Theob., a mangrove plant growing in mangrove forest, Sundarban, Bangladesh. Methods The endophytic fungi of experimental plants were identified by DNA amplification and sequencing of the internal transcribed spacer (ITS) region Moreover, cytotoxicity, antioxidant and antimicrobial tests were assessed. In addition, the screening of extracts was performed by visual detection using UV light. Results Three fungi namely CEDBE-1, CEDLE-6 and CEDLE-10 (internal strain no) were isolated as endophytic fungi and identified as Fusarium oxysporum , Clonostachys spp. and Fusarium solani respectively on the basis of morphological characteristics and DNA sequencing. The isolates were cultured at 28 0 C±2 for 21 days in Potato Dextrose Agar (PDA) media. The extracts of fungal isolates were examined at 100 µg/disc concentration for the screening of antibacterial activity and exhibited no activity against tested human pathogenic bacteria. The strain CEDBE-1 showed highest antioxidant activity of IC 50 value of 31.07 µg/mL comparing with the positive control ascorbic acid (0.74) and BHA (7.79) µg/mL. All isolates exhibited strong cytotoxic activity using brine shrimp lethality bioassay compared with the positive control tamoxifen. Preliminary chemical screening of the fungal extracts by thin layer chromatography technique revealed the presence of various compounds. Conclusions The findings indicate that endophytic fungal isolates explored from C. decandra has diversified biological activities which may be potential source of leads for new drug development.