Bioprospecting Endophytic Fungi Isolated from Cephalotaxus mannii Hook f. as Prolific Sources of Antibacterial, Anticancer, and Antioxidant Agents

Cephalotaxus mannii Hook f. is a rare medicinal plant used for leukemia treatment, however its fungal endophytes as a promising resource of pharmaceutical compounds remain poorly characterized. The present study is the first research on endophytic fungi associated with C. mannii collected in Vietnam and their potent biological activities. A total of 18 endophytic fungi were isolated; according to the results of morphological and internal transcribed spacer (ITS) sequence analyses, they belonged to six genera: Penicillium , Fusarium, Aspergillus, Diaporthe, Megasporoporia , and Trichoderma . Among these strains, the ethyl acetate extracts of Penicillium citrinum WDF8 and Fusarium perseae WDF12 showed remarkable antibacterial activity against at least 5 tested bacteria. Of note, only the WDF12 extract displayed potential cytotoxicity against A549 and MCF7 cancer cell lines with IC 50 values at 13.4 ± 0.9 and 17.8 ± 2 µg/mL, respectively. Further cytotoxicity evaluation led to the identification of 10-deacetylbaccatin III-10-O-acetyl transferase ( dbat ) gene essential for the biosynthesis of the anti-cancer drug paclitaxel in the fungal strain WDF8. Both extracts also showed strong antioxidant activity against DPPH, hydroxyl, and superoxide anion radicals, attributed to a high level of polyphenols and flavonoids present. This study proved that endophytic fungi from C. mannii exhibit excellent antibacterial, anticancer, and antioxidant activities and may be promising candidates for the production of paclitaxel and new compounds.