Evaluating the anti-oxidant, anti-inflammatory and cytotoxic potential of β-carotene produced by Rhodotorula alborubescens from the garden soil.

In this study, the efficacy of β-carotene produced from the isolated yeast strain Rhodotorula alborubescens, for evaluating the in vitro antioxidant, anti-inflammatory, and cytotoxic activities were evaluated. In vitro anti-oxidant activities against various radicals, including hydroxyl, superoxide anion, nitrogen oxide, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric ion reducing anti-oxidant power (FRAP) and total antioxidant assay-cupric reducing antioxidant capacity (CUPRAC) were determined and showed good free radical scavenging (FRS) activity, with the FRS value (%) ranging from 20.01 ± 4.20% (DPPH, 1000 µg/mL) to 65.66 ± 6.08% (reactive nitrogen oxide, 50 µg/mL), however significant reducing activity was observed in the CUPRAC assay (IC50: 0.7794 ± 0.44 µg/mL). Also, the down-regulation was observed when IL-4, IL-5, and IL-13 interleukins were profiled for anti-inflammatory properties. In-vitro cytotoxic potential was also evaluated on human leukemia monocytic cell THP-1 cell line by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. In-vitro cytotoxic assay resulted in an IC50 value of 3.116 ± 0.55% with observed morphological changes, loss of membrane integrity, and shrinkage of the cells. Notably, β-carotene treatment significantly reduced the medium fluorescence intensity (MFI) levels, contributing to the redox balance protection. These results suggested the accessibility of Rhodotorula alborubescens as anti-oxidant, anti-allergic and cytotoxic, which can also be further studied for therapeutic, food and cosmetic industries application.