Antioxidant and Anti-Inflammatory Activities of Ethanol Extract and its Fractions from Acer tegmentosum Stem

In this study, the first purpose was to determine total phenolic, total flavonoid and total terpenoid content of the Acer tegmentosum ethanol extract and four different types of fractions, including chloroform, ethyl acetate, n-butanol and water. Among the samples, Acer tegmentosum ethanol extract and fraction of ethyl acetate showed the highest total phenolic, total flavonoid and total terpenoid content. The second purpose was to evaluate the antioxidant activity of the samples assessed by in vitro methods such as scavenging capacity of 2,2-diphenyl-1-picryl-hydrazyl-hydrate and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid free radicals. Especially, Acer tegmentosum ethanol extract and fraction of ethyl acetate showed the strongest scavenging capacity with the lowest half maximal scavenging capacity values of these free radicals. The third purpose was to evaluate the anti-inflammatory activity in the lipopolysaccharide-stimulated Ralph and William's cell line 264.7 macrophages treated with various concentrations of Acer tegmentosum ethanol extract and fraction of ethyl acetate, and no cytotoxic effect on the macrophages was observed at the concentration of 100 mu g/ml of this extract. It suggested that this extract suppresses the activation of macrophages to secrete both pro-inflammatory cytokines (interleukin-1 beta, tumour necrosis factor alpha, inducible nitric oxide synthase and interleukin-6) and enzyme (inducible nitric oxide synthase) and anti-inflammatory cytokine (interleukin-10). The fourth purpose was to identify some compounds in a sample responsible for the antioxidant and anti-inflammation activities. In high-performance liquid chromatography chromatograms, the peak retention times detected from Acer tegmentosum ethanol extract and fraction of ethyl acetate in comparison with those from reference standards identified six compounds such as gallic acid, salidroside, (-)-epigallocatechin, (+)-catechin, scopoletin and trans-ferulic acid. It suggested that these compounds are responsible for antioxidant and anti-inflammation activities. Taken together, Acer tegmentosum seems to be one of the most promising species as a therapeutic source against diseases.