Phytochemicals and Antioxidant Activity of Aqueous and Ethanolic Extracts of Mentha aquatica L.

In Vietnam, Mentha aquatica L. is often used as a spice in dishes, fragrance and pharmaceuticals. The tea made from the plants' leaves has been used as a traditional medicine for fevers, headaches, digestive disorders and mouthwash. The present study aimed to explore the phytochemical profile of aqueous and ethanolic extracts of M. aquatica L. leaves as well as their total phenolics content, total flavonoid content and antioxidant activity. Various bioactive constituents were detected in M. aquatica L. extracts, including alkaloid, flavonoid, terpenoid, tannin, coumarin, anthraquinone and saponin. Furthermore, the total content of phenolics of aquaeous extract was higher than ethanolic extract. We then evaluated the antioxidant capacity of these two extracts by using DPPH and ABTS scavenging assays. Results have shown that the aquaeous extract exhibited scavenging activity more actively against both free radicals, as compared to the aquaeous extract. Overall, the study proposed that M. aquatica L. leaves can be an enriched source of phytochemicals that can be used as natural antioxidants in multiple industries.