Isolation, anticancer potency and camptothecin – producing ability of endophytic fungi isolated from Ixora chinensis

Abstract

Abstract Purpose Camptothecin (CPT) is an important alkaloid used for anticancer treatment. It is mainly produced by two endangered and overharvested Camptotheca acuminata and Nothapodytes nimmoniana plants. Endophytic fungi are promising alternative sources for CPT production. This study aimed to evaluate the distribution of fungal endophytes in Ixora chinensis, their cytotoxic properties and camptothecin – producing ability. Methods In the present study, fungi residing within explants of Ixora chinensis were isolated and their CPT-producing capability of their endophytes was verified via TLC, HPLC, LC-HRMS and NMR analyses and compared with standards. In addition, MTT and SRB assays were selected to test the anticancer effect. Results The endophytic fungi collection of 62 isolates were assigned to 11 genera, with four common genera (Diaporthe, Phyllosticta, Colletotrichum, and Phomopsis) and seven less common genera (Penicillium, Botryosphaeria, Fusarium, Pestalotiopsis, Aspergillus, and Didymella). Moreover, the anticancer activity of extracts was assessed against human lung carcinoma (A549). Among 8 potential extracts, only Penicillium sp. I3R2 was found to be a source of CPT, while the remaining seven extracts have not been detected to contain CPT. Thus, other prominent endophytic fungi might be potential candidates of phytochemicals with anticancer properties. Conclusions The present study identified novel endophytic fungi from I. chinensis as prospective sources for camptothecin and other potential bioactive compounds.