Isolation and screening of Vinblastine from Endophytic Fungi

Abstract

Vinblastine is a chemotherapeutic drug often used for the treatment of bladder cancer. Vinblastine belongs to the group called vinea alkaloids, obtained from plants Cathramhus roseus (famiJy- Apocyanaceae), species occurring in West Indies and Madagascar and also cultivated in some parts of India The mechanism of action of vinblastine is inhibiting the assembly of microtubule by binding to tubulin. This results in arrest in the division of cells. Endophytic fungi are ubiquitous organisms found in plants, residing intercellular, at least fur a portion of their lives without causing apparent symptoms of infection. Most of the plants are known to harbor endophytes, They are chemical synthesizer inside plants which are able to produce bioactive substances with low toxicity toward higher organisms. Endophytes have the ability to produce a variety of secondary metabolites, providing researchers with numerous leads for compounds of pharmaceutical significance and possible development as new drugs. In this study, 20 endophytic fungi have been isolated from plants collected from various biodiversity hotspot in India used for screening of vinblastine. The endophytic fungi processing the potential to produce vinblastine were initially grown on Czapek Dox Medium. The culture filtrate was screened for their potential to produce vinblastine extracellularly. Subsequently secondary screening was carried out using Phytochemical approach. Out of 20 culture screened, two cultures viz #82CRSTNEY (I.Om£.), #6CRSTBRT (5.0mg). exhibited appreciable Vinblastine production. #42CRSTBRT produces appreciable amount of vinblastine (9.9ng).The anticancer potential of the fungal isolate #42CRSTBRT were tested by cytotoxiclty assay on A549 cell line by M1T reduction assay. Microscopic identification showed that #42CRSTBRT belongs to Fusarium sp. Further for molecular identification, genomic DNA of the #42CRSTBRT isolate was amplified using universal ITS primers. They showed an amplicon in size between 550-600bp. Further characterization is reasonable along with the molecular taxonomy of the endophytic isolates to develop them as a novel source of vinblastine production