Sideritis galatica Bornm.: A source of multifunctional agents for the management of oxidative damage, Alzheimer's's and diabetes mellitus

The antioxidant and enzyme inhibitory potential of different solvent extracts (petroleum ether, ethyl acetate, methanol and water) from Sideritis galatica were evaluated. Cholinesterase, α-amylase and α-glucosidase inhibitory activities of the extracts were tested by microtiter plate assays. Antioxidant abilities were tested using free radical scavenging (DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid) and NO), reducing power (FRAP (ferric reducing antioxidant power) and CUPRAC (cupric reducing antioxidant capacity)), total antioxidant capacity and chelating assays. Methanol and water extracts showed higher phenolic content, DPPH and ABTS scavenging activity and reducing power activities, while the petroleum ether and ethyl acetate extract had the highest inhibition abilities on the enzymes. 18 phenolic components in these extracts were detected by using high performance liquid chromatography-diode array detector (HPLC-DAD). Results obtained in this work indicate that S. galatica may be useful as a source of natural agents for the management of oxidative process, Alzheimer's disease and type II diabetes.