微量量热法研究天然虫草和人工虫草对大肠杆菌生长代谢的影响

考察天然虫草和人工虫草对大肠杆菌生长代谢的影响，评价虫草类中药的生物活性，为其质量控制提供研究基础。采用微量量热法，以指数生长期最大发热功率 (P_{1 max}) 和有效率 (E) 为指标，客观地表征天然虫草和人工虫草对大肠杆菌生长代谢的影响，并对实验结果进行聚类分析。结果显示，天然虫草和人工虫草有促进大肠杆菌生长、调节胃肠道微生态平衡的作用。与空白对照相比，当虫草质量浓度大于6.0 mg·mL⁻¹时，天然虫草对大肠杆菌生长代谢促进作用显著 (P < 0.05), 且与浓度间的量效关系良好 (r > 0.9)，人工虫草的促菌作用不显著 (P > 0.05), 且与浓度无明显的量效关系 (r < 0.6)，当虫草质量浓度 < 6.0 mg·mL⁻¹，促菌作用均不显著 (P > 0.05)。结果经聚类分析, 两者可较好地区分，提示微量量热法可用于评价天然虫草和人工虫草的质量, 在中药品质评价方面具有一定的应用潜力。

Investigation of metabolic action of Cordyceps sinensis and its cultured mycelia on Escherichia coli by microcalorimetry

This study is to investigate the effect of Cordyceps sinensis and its cultured mycelia on growth and  metabolism of Escherichia coli, and microcalorimetric method was carried out to evaluate its biological activity.  The study will provide the basis for the quality control of Cordyceps sinensis.  Experimental result will show the effect of natural Cordyceps sinensis and its cultured mycelia on growth and metabolism of Escherichia coli, with index of P_{1 max} and effective rate (E) by microcalorimetry, the data of experiment were studied by cluster analysis.  The results showed that Cordyceps sinensis and its cultured mycelia not only can promote growth and metabolism of Escherichia coli but also can regulate the balance of intestinal microecology efficiently.  When the concentrations of samples > 6.0 mg·mL⁻¹, natural Cordyceps sinensis can promote the growth and metabolism of Escherichia coli efficiently (P < 0.05) compared with the control group, and have better dose-effect relationship with concentration (r > 0.9), its cultured mycelia does not show conspicuous auxoaction (P > 0.05) and have not dose-effect relationship with concentration (r < 0.6); when the concentration of samples < 6.0 mg·mL⁻¹, all  samples does not show conspicuous auxoaction (P > 0.05).  Natural Cordyceps sinensis and its cultured mycelia can be distinguished by cluster analysis.  Microcalorimetry has a good prospect on the quality evaluation of the traditional Chinese medicine.