A comparative investigation of phytochemical contents and bioactivities of DMSO extracts obtained from black cumin and sesame seed oils

Although herbal oils have been studied for their well-known biological activities, the immiscibility of oils in aqueous solutions limits the accuracy of the in vitro assays, such as anticancer, antibacterial, antioxidant capacity, and total phenol content. In this study, we report phytochemical content analysis and biological activities of DMSO extracts obtained from black cumin (D-bc) and sesame (D-s) seed oils in vitro. Folin-Ciocalteu assay for phenol contents, aluminum chloride calorimetric assay for flavonoid contents, and CUPRAC assay for antioxidant capacities were performed to determine phytochemicals in the DMSO extracts. In bioactivity tests, the MTT cell proliferation assay against human bladder cancer (T-24) for anticancer activity and the agar disk diffusion assay against S. aureus and E. coli for antibacterial activity were carried out. According to content analysis, D-bc and D-s were determined to contain a significant amount of phenols with 8455.29±0.05 and 42882.48±0.05 µg gallic acid equivalent/g extract and flavonoids with 967.70±0.02 and 828.70±0.03 µg catechin equivalent/g extract, respectively. The antioxidant capacity was 6.98 mM Trolox equivalent for D-bc and 1.25 mM Trolox equivalent for D-s. Besides, both extracts showed antibacterial activity against S. aureus. According to the MTT cell proliferation test, the IC50 values after 48 h treatment of the D-bc and D-s were determined to be 0.2% and 0.55% against T-24 cells, respectively. DMSO as an extractant, presenting an alternative extraction technique to concentrate phytochemicals in herbal oils, was introduced in this study.