Vinblastine production by the endophytic fungus Curvularia verruculosa and their in vitro cytotoxicity

Abstract The current study was to isolate endophytic fungi producing high yields of indole alkaloids such as vinblastine analogous to their host Cathranthus roseus. Endophytic fungi were isolated from the leaves of C. roseus, identified as Curvularia verruculosa by molecular techniques, the sequence was deposited in NCBI (MK995628). Vinblastine producing endophytic fungus was grown in 1L Vinca medium for 21 days. The extract was examined for vinblastine by chromatographic techniques. TLC plates showed purple colour spot co migrated with authentic vinblastine and Rf was calculated by HPTLC (Vin 1 vinblastine −0.75; authentic vinblastine-0.78), these results confirmed vinblastine presence in the Vin1 extract. Further, the TLC purified fungal extract was examined by LC-MS, which revealed the exact mass of vinblastine ([M + H]+ m/z 811.51). The most important of the study is high yield production of vinblastine; hence, the extract analysed by HPLC revealed 182 μg/L vinblastine. The TLC purified fungal vinblastine was analysed for the cytotoxicity effect on HeLa cell line and it depicted a higher activity with IC50-8.5 μg/mL and apoptotic morphological changes were analysed. All the results revealed that the endophytic fungus Curvularia verruculosa produced vinblastine and for the first time in a surplus amount compared to other fungi.