OBJECTIVETo study the pharmacodynamic interaction of nourishing and tonifying blood effects of the herb pair consisting of Angelica sinensis and Ligusticum chuanxiong by response surface method.

METHODSThe blood deficiency rat model was induced by injecting N-acetylphenylhydrazine and cyclophosphamide. The effects of Angelica sinensis and Ligusticum chuanxiong in different proportions (0:1, 1:5, 2:5, 2:3, 1:1, 3:2, 5:2, 5:1, and 1:0) and at different concentrations on the peripheral blood index and the organ indices were observed. Then all indices were integrated to the total nourishing effect value by comprehensive index method. The interaction was analyzed by response surface method. The model parameters were estimated with nonlinear regression. The three-dimensional response surfaces were constructed with Matlab Software.

RESULTSIn the response surface, most compatibility of Angelica sinensis and Ligusticum chuanxiong showed synergistic action, some showed addition action, and few of them showed obvious antagonist action. The proportion of Angelica sinensis and Ligusticum chuanxiong from 4:1 to 2:1 and the dose of Angelica sinensis and Ligusticum chuanxiong from low to high showed addition action, while the other proportions showed obvious addition action at low dose and synergistic action at high dose.

CONCLUSIONSThe research results could provide scientific evidence for reasonable application of Angelica sinensis and Ligusticum chuanxiong in clinics of Chinese medicine. The quantitative analysis on drug interactions of herbal compatibility by response surface method could provide reference for relative studies.