Fungal Endophytes: A Novel Source of Cytotoxic Compounds

Abstract

Across the globe, cancer is the second most significant cause for mortality that was responsible for 8.8 million deaths in 2015, and the count is increasing at the alarming pace each year. The longer treatment protocols and the serious side effects of the existing anticancer drugs represent an urgent need to develop safe and effective anticancer drugs. Endophytic fungi offer the prolific source of novel metabolites that bears unique structural and functional capabilities with cytotoxic activity. In recent years, various bioactive metabolites possessing structural diversity have been identified from endophytic fungi and evaluated for their anticancer properties. Bioactive metabolites from endophytic fungi have potential to serve as a lead molecule for the pharmacological sector in the development of new drugs. The lower yield of metabolites is a major barrier for the utilization of these molecules for the treatment of cancer; therefore, alternate sources and production methods have been developed. The culture optimization to enhance yield and epigenetic means to activate silenced genes capable of producing novel metabolites were developed to obtain the fungal metabolites in higher quantities. The present review provides a comprehensive data of bioactive metabolites isolated from endophytic fungi harboring terrestrial plants during 2012–2018 (up to June 2018) with focus on their chemical structure, their cytotoxic capabilities, and their mechanism of action. The outlook of epigenetic modulation is discussed in perspectives of enhancing yield and identification of unidentified metabolites.