中文摘要：

目的：研究pH值对诃子体外抑菌活性的影响作用。方法：测定诃子溶液的pH值，以及不同缓冲体系下诃子对细菌的最低抑菌浓度（MIC）。结果：诃子溶液的pH值呈中等酸性（1g／ml的诃子水煎液的pH≈3．44）；诃子水煎液直接加入MH琼脂中测定其MIC值时，由于低pH值的干扰造成表观抑菌活性偏高，经过磷酸缓冲体系调节pH值后抑菌活性下降，两者相差约4倍。结论：临床使用时，诃子在人体内近中性的pH环境中起作用，因此体外考察诃子抑菌活性时有必要调节检测体系的pH值使之接近中性，以便于体外抑菌效果能与临床使用效果更为接近。

英文摘要：

Objective： Determination the effect of pH on the MIC of Terminilia chebula Retz. to bacteria. Method： Deterination the pH of the hot water extract of the fruit of Terminilia chebula Retz., and the MIC of the hot water extract of the fruit of Terminilia chebula Retz. in phosphate - buffered saline or physiological sa- line. Result： The pH of the hot water extract of the fruit of Terminilia chebula Retz. was about 3.44. The MIC of the hot water extract of the fruit of Terminilia chebula Retz. in phosphate - buffered saline was 4 times lower than that of in physiological saline. Conclusion： By clinical prescription, the Terminilia chebula Retz acted in the body fluid of human beings with neutral pH , so that the MIC of Terminilia chebula Retz to bacteria in vitro in phosphate- buffered saline maybe more accord with the action in body fluid of human beings.