In Vitro Anticancer Activity of Staphyloxanthin Pigment Extracted from Staphylococcus gallinarum KX912244, a Gut Microbe of Bombyx mori.

The present study reports the in vitro biological nature of the pigment produced by Staphylococcus gallinarum KX912244, isolated as the gut microflora bacterium of the insect Bombyx mori. The purified pigment was characterized as Staphyloxanthin based on bio-physical characterization techniques like Fourier transform infrared spectroscopy, high performance liquid chromatography, Proton nuclear magnetic resonance spectroscopy (1H NMR), Liquid chromatography-Mass spectroscopy and Gas chromatography-Mass spectroscopy. The Staphyloxanthin pigment presented considerable biological properties including in vitro antimicrobial activity against pathogens Staphylococcus aureus, Escherichia coli and Candida albicans; in vitro antioxidant activity by % DPPH free radical scavenging activity showing IC50 value of 54.22 µg/mL; DNA damage protection activity against reactive oxygen species and anticancer activity evaluated by cytotoxicity assay against 4 different cancer cell lines like the Dalton's lymphoma ascites with IC50 value 6.20 ± 0.02 µg/mL, Ehrlich ascites carcinoma having IC50 value 6.48 ± 0.15 µg/mL, Adenocarcinomic human alveolar basal epithelial cells (A549 Lung carcinoma) bearing IC50 value 7.23 ± 0.11 µg/mL and Mus mucus skin melanoma (B16F10) showing IC50 value 6.58 ± 0.38 µg/mL and less cytotoxicity towards non-cancerous human fibroblast cell lines (NIH3T3) with IC50 value of 52.24 µg/mL. The present study results suggest that Staphyloxanthin acts as a potential therapeutic agent especially due to its anticancer property.