以棋盘法测定汉防己甲素与伊曲康唑的体外联合抗烟曲霉作用

目的 探讨汉防己甲素在体外对伊曲康唑抗烟曲霉活性是否有增效作用。方法 参照美国临床和实验室标准协会（CLSI）推荐的M38-A2方案，采用棋盘式微量液基稀释法，以21株烟曲霉临床株为研究对象，测定汉防己甲素联合伊曲康唑对其的抗真菌活性，以OD值测定法判读最低抑菌浓度，并以FICI法评价结果,同时以其中的AF46株为代表，用等效线图解法验证结果。结果 汉防己甲素与伊曲康唑单独作用于上述烟曲霉临床株的最低抑菌浓度值分别为256~512 μg/mL、0.125~32 μg/mL,联合用药时的最低抑菌浓度值分别降至8~64 μg/mL、0.03~2 μg/mL，且终点清晰，“拖尾现象”消失，FICI值为0.08~0.38，均表现为显著协同作用。AF46株的等效曲线呈凹形，也表明具有协同作用。结论 汉防己甲素在体外对伊曲康唑抗烟曲霉活性有显著增效作用。

In vitro interactions between tetrandrine and itraconazole against Aspergillus fumigatus determined by the checkerboard method

The aim was to detect the in vitro antifungal interactions between tetrandrine (TET) and itraconazole (ITC) against Aspergillus fumigatus. According to the Clinical and Laboratory Standards Institute(CLSI) M38-A2 guidelines, we used 21 clinical isolates of Aspergillus fumigatus to evaluate the response through the checkerboard microdilution method. We employed the spectrophotometric method to determine the results of the interactions, and the nature of interactions was assessed by the fractional inhibitory concentration index (FICI) model. The result was also verified by isobologram with AF46 as sample. The MICs of TET and ITC alone were 256~512 μg/mL、0.125~32 μg/mL, respectively. While the MICs of TET and ITC in combination were 8~64 μg/mL and 0.03~2 μg/mL, with the disappearance of the so-called “trailing” phenomenon. The FICI of the drugs in combination ranged from 0.08~0.38, revealing strong synergism between TET and ITC. Synergism was also demonstrated in that the corresponding isobole of AF46 was concave. Our findings suggest that when combined with ITC, TET showed potent synergism in antifungal activity.