OBJECTIVETo observe the in vitro antioxidant interaction of different preparations and proportions of Danggui-Chuanxiong drug pair in the DPPH free radical scavenging rate with the response surface methodology.

METHODThe 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging rate method was adopted for determining the antioxidant activity of extracts from Danggui-Chuanxiong with 10 proportions and three extraction processes. The response surface methodology was used to determine the parameters of the dose-effect curve and establish a three-dimensional response surface model. The three-dimensional response surface graph was constructed with Matlab software.

RESULTAll of the 30 samples with different proportions and preparations had antioxidant effect in scavenging free radicals and a remarkable dose-effect relationship. Their water extracts had a narrow synergistic range, with only spot distribution. Their antagonist ranges were districted in six bands of various widths. The synergistic ranges of ethanol extracts were districted in small bands, with the antagonist ranges scattered in points. The synergistic ranges of their water-alcohol extracts were distributed in three bands, with their antagonist ranges scattered in points. In short, the water-alcohol extracts showed a wider synergistic range than ethanol extracts, followed by water-extracts. All of the three extraction processes showed no obvious synergistic and antagonist effects.

CONCLUSIONThe quantitative study on the interaction of traditional Chinese medicines with different compatibilities with the response surface methodology provides reference of thoughts and methods for relevant studies.