OBJECTIVETo assess and compare the in vitro anti-oxidative activities among Siwu Decoction Serial Recipes, their composed crude herbs, and main aromatic acids they contained.

METHODSTheir anti-oxidative activities (including Siwu Decoction and correlated recipes such as Taohong Siwu Decoction, Xiangfu Siwu Decoction, Shaofu Zhuyu Decoction, and Xiongqiong Decoction, 16 kinds of crude herbs, and main aromatic acids they contained) were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical clearance method.

RESULTSThe selected five decoctions showed obvious activities of scavenging free radicals. Siwu Decoction was better than other decoctions in scavenging free radicals and Xiongqiong Decoction was the least. Among the 16 kinds of crude herbs, red peony root, white peony root, safflower, ligustici chuanxiong, common aucklandia root showed the strongest activities, while peach seed showed the poorest activities. Among aromatic acids, gallic acid, protocatechuic acid, vanillic acid, caffeic acid, chlorogenic acid, p-coumaric acid, and ferulic acid showed obvious anti-oxidative activities in scavenging free radicals, showing obvious dose-effect correlation. p-hydroxybenzoic acid, benzoic acid, and cinnamic acid showed no activities on scavenging free radicals (P > 0.05).

CONCLUSIONSiwu Decoction and aromatic acids contained in correlated decoctions played significant roles in anti-oxidative activities.