ANTICANCER AGENTS FROM ENDOPHYTES

ANTICANCER AGENTS FROM ENDOPHYTES

The cytotoxic effect of fungal taxol isolated fromthe culture filtrate of M1D and PDB, was detectedand quantified by using in vitro apoptotic methodof assay23 on various cancer cells, at variousconcentrations. The human cancer cell lines(HLK210, H116, Int407, HL251 and BT220) wereprocured from the National Centre for CellSciences (NCCS), Pune, India. Themorphological changes of the cancer cells whichwere treated with different concentrations offungal taxol ranging between 0.005 ¦МM and 5 ¦МMwere incubated for 48 h. The cells were thenstained (DNA staining) with 0.5 mg/ml propidiumiodide in phosphate buffered saline (PBS) for 15min and de-stained in PBS solution. AfterISSN 0975-6299 Vol.1/Issue-3/Jul-Sep.2010www.ijpbs.net Microbiology7treatment with different concentrations of fungaltaxol, the cell morphology was determined by lightmicroscopy. In all, five different fields wererandomly selected for counting at least 500 cells.The percentage of apoptotic cells was calculatedfor each experiment. Cells designated asapoptotic were those that displayed thecharacteristic morphological features ofapoptosis, including cell volume shrinkage,chromatin condensation and the presence ofmembrane bound apoptotic bodies. The cells inthe apoptosis were calculated by using thefollowing formula.Percentage of apoptotic cells = Number ofapoptotic cells/ Total number of cells ЎБ 100Cytotoxicity effect of fungal taxol isolatedfrom the endophytic fungus was detected andquantified using apoptotic assay23 on variouscancer cellsThe taxol-producing endophytic fungihad previously tested for their cytotoxic activityvia an apoptotic assay against different cancercell lines. They showed strong cytotoxic activity inthe presence of BT220, H116, Int407, HL251 andHLK210 human cancer cells in vitro. Previousreport of the endophytic fungus showed thestrong cytotoxic activity towards BT 220, H116,Int 407, HL 251 and HLK 210 human cancer cellsin vitro, tested by Apoptotic assay13,30.

Recently,Taxol was tested using an in vitro cytotoxicityassay against human cancer cell lines (A-549 forlung cancer, HEP-2 for liver cancer, OVCAR-5 forovarian cancer) in comparison with the standardauthentic example, resulting in comparableactivities20.Cytotoxicity effect of fungal taxol frommedicinal plants were further tested usingapoptotic assay on various cancer cells viz.,human breast cell BT220, human colon H116,human intestine Int407, human lung HL251 andhuman leukemia HLK 210. It is indicated that withthe increase of taxol concentrationfrom 0.005 ¦МMto 0.05 ¦МM, taxol induced increased cell deaththrough apoptosis. With further increase of taxolconcentration from 0.05 ¦МM to 0.5 ¦МM, the taxolinducedcell death through apoptosis onlyincreased slightly. When the taxol concentrationwas increased from 0.5 ¦МM to 5 ¦МM, the taxolinducedcell death through apoptosis decreaseddramatically. It was observed at low to mediumconcentration (0.005ЁC5 ¦МM), the efficacy of fungaltaxol was quite dependent on the specific celltype. It has been reported that taxol at lowconcentrations (nM) induces cell apoptosis andthe efficacy of taxol is quite dependent on thespecific cell type. This also supports the previousfindings of other groups that at low concentration,taxol inhibits cell proliferation by blocking mitosis.

CONCLUSIONЈєThe aim of this review clearly mention about theisolation and characterization of taxol producingendophytic fungi from medicinal plants. In thereview, it is confidently evident that thespectroscopic and chromatographic estimates areclose to reality, given fact that the fungal taxoland standard taxol give identical results. It alsoindicates that the formation of taxol by endophyticfungus was found to be the highest and suggeststhat the fungus can serve as a potential speciesfor genetic engineering to enhance the productionof taxol. The significance in the discovery of fungithat produce taxol indicate that there areabundant resources of fungi that produce taxol. Abackground understanding that involves somespecific examples and rationale of the presenceof endophytic microorganisms in higher plants willaid in the development of a drug discoveryprogram involving these organisms. A search fora rare and thus, expensive product such as Taxolmay be facilitated by examining the endophyticmicroorganisms of certain plants for their ability tomake this drug. To meet the urgent need of clinicand scientific research, besides Taxus supply,other approaches to obtain Taxol have also beendiscussed here.

ACKNOWLEDGEMENTSЈЎ