Phenolic profiles, antioxidant activities and enzyme inhibitory effects of an Algerian medicinal plant (Clematis cirrhosa L.)

Clematis cirrhosa L. an Algerian medicinal plant widely distributed in the North of Algeria. It is used in traditional medicine for rheumatism pain and as diuretic agent. In this study methanol and hydromethanol extracts of Clematis cirrhosa were subjected to several tests in order to determine their phenolic compositions, antioxidant activities, and their enzyme inhibitory activities. The total polyphenols and total flavonoids contents were evaluated using colorimetric methods. The antioxidant activities were measured by various methods, namely free radical (DPPH. and ABTS.+) scavenging tests, and ion reducing capacity assays (FRAP and CUPRAC). The two extracts were examined for their inhibition activities of α-amylase, α-glucosidase, cholinesterase, tyrosinase enzymes. Also, the phenolic profiles of the studied extracts were determined by HPLC/DAD. The results showed that methanol extract had the highest antioxidant capacity with a highest amount of total phenol (84.05±0.8 mg GAE/g) and total flavonoid (114.60 ± 2.42 µg QE/g). The two extracts had noticeable enzyme inhibitory effects towards tyrosinase, AChE, BChE, α-glycosidase and α-amylase. HPLC/DAD analysis revealed that the studied extracts were rich on benzoic acid, hydroxybenzoic acid, catechin, caffeic acid, and epicatechin.