Production, nanoformulation, and potential anticancer effect of camptothecin metabolites from biomass of Aspergillus niger

In the current investigation, the enhanced cytotoxic impact of gold nanoparticle–loaded camptothecin—a bioactive metabolite produced by a soil isolate of Aspergillus niger against breast cancer cell line (MCF 7)—was studied. Camptothecin (CPT) was isolated from Aspergillus niger biomass followed by loading with chemogenic gold nanoparticles, and the synthesized nano-drug conjugate was characterized by suitable techniques. Anticancer activity against MCF 7 cell line was studied by determination of cell viability and morphometric changes including apoptosis, biochemical, and molecular marker expression pattern. Active principles of CPT were readily extracted with chloroform + methanol extract of A. niger biomass. The maximum yield of CPT was 0.132 g/L. Extracted CPT was loaded onto chemically synthesized gold nanoparticles (CPT-AuNp) that brought about a highly stable core shell-like structure with particle sizes ranging from 60 to 70 nm. Prepared nanoformulation recorded noteworthy anticancer activity against breast cancer cells. Cell viability of the cancer cells was highly reduced in CPT-AuNp treatment. The lethal concentration (IC 50 ) was recorded at 50.5 µg, whereas free gold nanoparticles and free camptothecin were at 301 and 295 µg, respectively, which showed the enhanced cytotoxicity of AuNp-CPT against the tested cancer cell line. Most significantly, CPT-AuNp treatment induced apoptosis and characteristic changes in enzymatic antioxidants which includes catalase (CAT), superoxide dismutase (SOD), and glutathione s-transferase (GST). Expression pattern changes of gene-like PARP and Bax genes revealed a marked impact on the molecular markers. From these findings, it is clear that the nanoformulated camptothecin can be used as an effective and safe anticancer agent against life-threatening diverse cancer types.