Phytochemical analysis, antioxidant activities and optimized extraction of embelin from different genotypes of Embelia ribes Burm f.: a woody medicinal climber from Western Ghats of India

Medicinal importance of Embelia ribes Burm f. is known since ancient time. Its berries are the main ingredient in Vidanga' or 'Baibidanga'-a component of ayurvedic formulations and possess medicinal properties such as antihelmintic, anticancer, neuroprotective and antidiabetic. Studies were conducted on phytochemicals, antioxidant activities, extraction efficiency of embelin from ten genotypes. Methanolic extract of berries from Nagavelli accession exhibited the highest total phenolic content (18.18 ± 0.14 mg GAE/g DW); whereas, ethanolic extract showed highest total flavonoid content (8.35 ± 0.20 mg RE/g DW). The antioxidant activities (AOA) were assessed and noted that ethanolic and methanolic extracts of berries from Nagavelli (NAG) accession revealed highest activities in terms of DPPH radical scavenging activity (67.48 ± 0.17%) and FRAP (66.73 ± 0.60 mg Fe(II)/g DW), respectively. In AOA analysis, berries extracted with different solvents were positively correlated with TPC. Principal component analysis revealed TPC and TFC were the most influencing components for strong antioxidant activities in E. ribes. Reverse phase high performance liquid chromatography (RP-HPLC) was used to quantify embelin content and its optimize extraction using various methods. In the preliminary studies, berries from NAG accession revealed highest (1.770%) embelin content. Further, berries from NAG accession were subjected to various extraction methods and found three fold increase (5.08%) in embelin content in microwave assisted extraction (90 s). Present study suggested that NAG accession found to be a promising source of natural antioxidants and embelin that can be used in pharmaceutical industries.

Keywords: Antioxidant; Embelia ribes; Embelin; RP-HPLC; Total alkaloid content; Total phenolic content.