Phenolic Composition, In Vitro Alpha-Amylase and Pancreatic Lipase Inhibitory Effects, Anti-Inflammatory and Antioxidant Activities of Ephedra altissima

Abstract

This study aimed to investigate the phytochemical composition, alpha-amylase and pancreatic lipase inhibitory activities and anti-inflammatory and antioxidant properties of the crude extracts (petroleum ether, ethyl acetate and n-butanol) obtained from the aerial parts of Ephedra altissima. The characterization of the phenolic compounds in crude extracts was performed by high performance liquid chromatographyphotodiode array detection-electrospray ionization-mass spectrometry and the in vitro alpha-amylase and pancreatic lipase inhibitory activities were evaluated using starch and p-nitrophenyl butyrate as substrates, respectively. Furthermore, the anti-inflammatory activity was carried out by bovine serum albumin denaturation method and the antioxidant capacity was assessed using five different assays. Flavonol and ï¬avone glycoside derivatives and phenolic acids, especially isovitexin-2-O-rhamnoside and vicenin II were the major compounds in the n-butanol extract. Otherwise, the ethyl acetate extract presented kaempferol-3-O-rhamnoside, quercetin-3-O-rhamnoside and protocatechuic acid as its main compounds. The n-butanol extract revealed the highest content of total phenolic compounds. The results for antioxidant activity showed that ethyl acetate extract possesses the strongest activity in all the tested methods. Moreover, the ethyl acetate extract displayed the best anti-inflammatory, alpha-amylase and pancreatic lipase inhibitory activities with half-maximal inhibitory concentration values of 126.43, 9.02 and 289.11 μg/ml, respectively. These results give obvious support to the use of Ephedra altissima in traditional medicine for the treatment of diabetic diseases. Also, the moderate alpha-amylase inhibitory activity of Ephedra altissima extracts make advantage of its therapeutic applications compared to the synthetic drugs, since their strong alphaamylase inhibitory effects are associated to many digestive adverse effects including the abnormal bacterial fermentation in the colon.