Optimization of polyphenol extraction from Eclipta prostrata L. by response surface methodology

Eclipta prostrata L. is a medicinal herb used in many folk remedies in Asian countries because it contains valuable components such as alkaloids, polyphenols, steroids, saponins, triterpenes, etc. In particular, polyphenol compounds extracted from this plant show antioxidant, anti-inflammatory, antibacterial activities, etc. This study focused on investigating the factors affecting the extraction of polyphenol from Eclipta prostrata. The highest total polyphenol content was obtained using 50% ethanol at 60oC for 90 min with a solvent:material ratio of 40:1 mL/g. Since, the extraction conditions were optimized by response surface methodology according to central composite design. The results showed that the polyphenol content obtained was 55.92 mg GAE/g dw with a solvent:material ratio of 43:1 mL/g at 64oC for 97 min. In addition, the antioxidant activity of the extract from Eclipta prostrata was also determined with an IC50 value of 78 µg/mL through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method.