Bergenin content and free radical scavenging activity of bergenia extracts

Abstract

Our research was focused on the evaluation of bergenin content and free radical scavenging activity of extracts prepared from three different species of Bergenia-B. Crassifolia (L.) Fritsch., B. Ciliata (Haw.) Sternb. And B. x ornata Stein. Collected during different seasons. Using an HPLC method, the highest total amount of bergenin was revealed in the leaves of B. x ornata and B. Crassifolia (4.9-5.1 mg.g-1). Free radical scavenging power was determined by two methods-FRAP and NADH. The best free radical scavengers were B. Crassifolia (FRAP: 6.7-15.9 mg GAE.100g-1; NADH: 20.3-50.9%) and B. ornata (FRAP: 13.7-15.2 mg GAE.100g-1; NADH: 29.3-31.1%). The lowest content of bergenin and the weakest radical scavenger was B. Ciliata (bergenin: 3.1 mg.g-1; FRAP: 5.5-11.0 mg GAE.100g-1; NADH: 23.2-25.6%). The presence of a large percentage of bergenin is responsible for the radical scavenging activity, as shown by the results from the FRAP and NADH assays. Significant, positive correlation was found between bergenin content and radical scavenging activity in both methods.