Phenolic profile, enzyme inhibitory and antioxidant activities of two endemic Nepeta species: Nepeta nuda subsp. glandulifera and N. cadmea

Abstract

It is known that the local people commonly use some Nepeta species as diuretic, spasmolytic, bronchodilator and sedative agents. In addition, these species are also used topically due to their antiseptic properties. This study aimed to deal with the in vitro antioxidant and enzyme inhibitory activities of the methanolic extracts of two endemic. Nepeta species (Nepeta nuda L. subsp. glandulifera Hub.-Mor. & Davis and N. cadmea Boiss.) from Turkey. N. nuda subsp. glandulifera was found to contain more phenolics and flavonoids than N. cadmea. N. nuda subsp. glandulifera was also found to have considerable amounts of chlorogenic and ferulic acids (63.52 and 14.65 mg/g extract), and showed higher antioxidant activity in almost all test systems, except metal chelating assay. Meanwhile in β-carotene bleaching assay, it was found to be as active as BHT and trolox (91.23%). In the enzyme inhibition assay, the extracts showed weak inhibitory activity on AChE, α-amylase and α-glucosidase. Inhibitory activity of N. nuda subsp. glandulifera on these enzymes was found to be 1.26 mg GALAEs (galanthamine equivalents)/g extract, 0.36 and 3.67 mmol ACEs (acarbose equivalents)/g extract, respectively.