Comparative analysis of different bioactivities of Curcuma longa, Nigella sativa seeds, and Camellia sinensis extracted by four different methods: A green way to reduce oxidative stress.

Medicinal use of plants is as old as human history. Curcuma longa, Nigella sativa seeds, and Camellia sinensis have been widely used in various remedies since ages. In this study, the effect of extraction method on different bioactivities and phytochemical constituents of Curcuma longa, Nigella sativa seeds, and Camellia sinensis were evaluated and compared using single solvent system (50% ethanol). Plant extracts were prepared by percolation-assisted extraction, sonication-assisted extraction, microwave-assisted extraction, and polyphenol extraction. Following phytochemical screening, extracts were screened for antioxidant activity, antihemolytic activity, osmotic tolerance, and osmotic fragility. All plant extracts showed good phytochemical content irrespective of extraction method. However, activities in vitro antioxidant assays were dependent on plant as well as on extraction methods. Promising results were observed for antihemolytic activity against hydrogen peroxide-treated erythrocytes. Overall, Camellia sinensis exhibited the highest bioactivities followed by Curcuma longa and Nigella sativa seeds.