Effect of extraction methods on bioactives profile, antioxidant potential and anticancerous properties of Murraya koenigii leaves

Murraya koenigii (curry leaves) is a culinary spice rich of several bioactives. Many green extraction processes have recently been developed to isolate bioactives from herbs and spices. However, selecting an ideal extraction method to prepare an optimum extract rich in polyphenols and other bioactives is essential. Here, we have performed seven different extraction methods: ultrasonic-assisted extraction, maceration, cold extraction, soxhlet, microwave-assisted extraction (MAE), percolate, and homogenate to extract bioactives from curry leaves. We found that different extraction methods at various conditions influence the yield of bioactives, which can alter their bioactivity, such as antioxidant and anticancer properties. Among the extractions, microwave-assisted curry leaf extract (MA-CLE) yielded the highest content of phenols and flavonoids; thereby, MA-CLE has shown a higher antioxidant capacity than other extracts. Hence, we have selected MA-CLE for further study, where several bioactives, such as glycoside-bound flavonoids, terpenoids, and alkaloids, were identified through LC-MS/MS analysis. We found through RP-HPLC that MA-CLE is rich of resveratrol, rutin, coumarin, vallinic acid, and gallic acids. Among them, resveratrol was found to be the highest in MA-CLE. As MA-CLE is rich of several bioactives and has also shown greater antioxidant activity, further we have investigated the anticancer properties of MA-CLE against different cancer cells, including breast, lung, ovarian, and melanoma. We found that MA-CLE is a potent anticancer agent, predominantly against lung cancer, over other cancer cells. Overall, we found MAE can improve the phytochemical content and enhance the functional properties of curry leaf extract. {GRAPHIACAL ABSTRACT}