Plant-microbe interactions implicated in the production of camptothecin - An anticancer biometabolite from Phyllosticta elongata MH458897 a novel endophytic strain isolated from medicinal plant of Western Ghats of India

Endophytic wild fungal strain Phyllosticta elongata MH458897 isolated from medicinal plant Cipadessa baccifera from the Western Ghats region of Sathyamangalam Tiger Reserve Forest. This endophytic fungus has potential of effective anticancer drug Camptothecin (CPT). Endophytic fungi act as key symbionts in-between plants and ecosystem in the biosphere. This recently identified microbial population inside the plants produces many defence metabolites against plant pathogens. Among these defense metabolites, CPT gained much attention because of its effective anticancer activity. The maximum yield of CPT produced by optimizing the various factors like DEKM07 medium, pH 5.6, incubation time using Response Surface Methodology based on Central Composite Design. Extracted CPT is characterized using High Performance Liquid Chromatography and Electrospray ionization-Mass spectrometry. The highest yield of CPT was 0.747 mg/L was produced at optimized factors of dextrose - 50 g L-1, peptone - 5.708 g L-1, magnesium sulphate - 0.593 g L-1, and incubation time - 14 days. In-vitro MTT assay revealed the CPT derivatives were cytotoxic to A-549 cancer cell line (IC50 58.28 mu g/ml) as nearly compared to the (IC50 51.08 mu g/ml) standard CPT. CPT producing strain P. elongata from C. baccifera has the potential of CPT biosynthesis, and could be an effective anticancer bio metabolite. This compound has been described in the literature to be an effective anticancer metabolite. Our findings support the novel lifesaving anticancer drug from endophytic fungus in forest ecosystem concludes effective utilization of key symbionts will safeguard the humans and forest ecosystem.

Automated summary

An endophytic wild fungal strain Phyllosticta elongata MH458897 isolated from the Western Ghats region of Sathyamangalam Tiger Reserve Forest, has the potential to produce an effective anticancer drug Camptothecin (CPT). This endophytic fungus produces defense metabolites against plant pathogens, with CPT gaining attention for its effective anticancer activity. Optimized factors such as medium, pH, and incubation time were found to yield the highest amount of CPT, which showed cytotoxic effects on cancer cell lines in vitro.