In vitro enzyme inhibitory properties, antioxidant activities, and phytochemical studies on juniperus drupacea

Abstract

Juniperus drupacea Labill. is used for medicinal purposes and to obtain a traditional food product “pekmez” for centuries. We aimed to evaluate antidiabetic and antioxidant activities of the extracts prepared from J. drupacea fruits, leaves and branches. Therefore, α-amylase and α-glucosidase inhibitory effects and antioxidant activities of the water, ethyl acetate, and methanol extracts were evaluated. Additionally, total phenolic and total flavonoid contents of the extracts were investigated. Standardization of the methanol extracts on amentoflavone and umbelliferone was performed using a RP-HPLC-DAD method. All extracts showed excellent and dose dependent inhibitory effect on α-glucosidase enzyme. Moreover, fruit methanol extract (99.92 ± 0.30%) and leaf methanol extract (99.44 ± 1.78%) were more effective than reference drug Acarbose (98.88 ± 0.07%) at 1 mg/ml concentration. On the other hand, the extracts rich in flavonoids and phenolics showed remarkable antioxidant activity. Results of HPLC analysis revealed that amentoflavone was detected in serious amount especially in the leaves as 0.148±0.001 g/100 g dry weight. Umbelliferone was determined in minor amount in both leaves and branches.