Anti-oxidative and anti-proliferative activities of extracted phytochemical compound thymoquinone

To evaluate the anti-oxidant and anti-proliferative potential of Thymoquinone extracted from the essential oil of indigenous herbs of Nigella sativa and Thymus vulgaris.

Extraction and quantification of Thymoquinone was carried out in July, 2017 in Department of Environmental Science, Lahore College for Women University (LCWU), Lahore. Thymoquinone was extracted from seeds of Nigella Sativa and aerial parts of Thymus vulgaris by employing soxhlet extraction with 1:4 ratios of nhexane and methanol. High Performance Liquid Chromatography was used to quantify Thymoquinone from the methanolic extracted oil of sample by applying calibration curve method. Extracted Thymoquinone was identified by sample peaks obtained at retention time were compared with peak of standard Thymoquinone at respective time. The Thymoquinone obtained from both samples was then subjected to Fourier-transform infrared spectroscopy for confirmation by identifying its functional groups. Anti-oxidant activities of both samples were measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assay in Department of Environmental Science, LCWU. In-vitro anti-proliferative activities of extracted Thymoquinone were evaluated in HeLa cell cancer lines by cell proliferations Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay in Department of Microbiology, University of Veterinary and Animal Sciences (UVAS), Lahore. SPSS 18 and Graph pad prism 18 was used for data analysis.

Soxhlet extraction with solvents ratios yielded 48.92% oil from Nigella sativa and 23.2 % from Thymus vulgaris. High Performance Liquid Chromatography peak of standard Thymoquinone was measured at retention time of 5.5 min which was then compared with the peak obtained from both samples at the similar retention time. The extracted Thymoquinone from both samples were quantified by calibration curve method showing 614.25 mg/L from Nigella sativa and 548.86 mg/L from Thymus vulgaris. The two anti-oxidant assays of both samples compared with standard Thymoquinone showed significant scavenging activities in dose amount manner. Cell proliferation of HeLa cancer significantly decreased with dose response manner (p<0.01), showing highest cell death in high concentration of Thymoquinone. Inhibitory concentration 50 (IC50) of cancer cell line treated with Nigella sativa oil was 0.5 μM and Thymus vulgaris was 18 μM compared to standard Thymoquinone, showing Inhibitory concentration50 (IC50) of 6 μM using Graph pad prism v.8.0.

Both Nigella sativa and Thymus vulgaris were found to be the best source of Thymoquinone as chemotherapeutic drug expressed potent anti-oxidant and anti-proliferative activities.