Free radical scavenging, angiotensin I-converting enzyme (ACE) inhibitory, and in vitro anticancer activities of ramie (Boehmeria nivea) leaves extracts

The objectives of this study were to evaluate the antioxidant activity, angiotensin I-converting enzyme (ACE) inhibitory activity, and anticancer activity of ramie (Boehmeria nivea) leaves (RL). The RL was extracted with 70%(v/v) ethanol (RLE) and fractionated with the solvents of hexane, chloroform, ethylacetate, and aqueous. The ethylacetate fraction (EF) contained the highest phenolic contents of 651.65 mg/g, followed by RLE of 148.72 mg/g. The EF showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging with a 50% inhibition concentration (IC₅₀) of 0.097, 0.129, and 0.191 mg/mL, respectively. The ACE-inhibitory activity of EF was 80.32% at a concentration of 0.1 mg/mL. The EF showed growth-inhibitory effect of 67.21% at 0.25 mg/mL on the LoVo cell line, and 56.08% at 0.25 mg/mL on the NCI-H460 cell line, respectively. Therefore, it was suggested that the RL were potential materials for use as functional food and medicine.