The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.
YAN DanHAN YuMeiLUO JiaoYangZHANG PingTANG HuiYingPENG ChengXIAO XiaoHe
The inhibitory effects of three berberine alkaloids (BAs) from rhizome of Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Staphylococcus aureus growth were investigated by mi- crocalorimetry. The power–time curves of S. aureus with and without BAs were acquired; meanwhile the extent and duration of inhibitory effects on the metabolism were evaluated by studying the growth rate constant (k), half inhibitory ratio (IC50), maximum heat-output power (Pmax), peak time of maximum heat-output power (tp) and total heat production (Qt). The value of k of S. aureus in the presence of the three BAs decreased with the increasing concentrations of BAs. Moreover, Pmax was reduced and the value of tp increased with increasing concentrations of the three drugs. The inhibitory activity varied with different drugs. The values of IC50 of the three BAs are respectively, 101.4 μg/mL for berberine, 241.0 μg/mL for palmatine and 792.3 μg/mL for jateorrhizine. The sequence of antimicrobial activity of the three BAs is: berberine > palmatine > jateorrhizine. It is suggested that the functional group me- thylenedioxy or methoxyl at C2 on the phenyl ring could possibly improve antimicrobial activity more strongly than hydroxyl at C2 on the phenyl ring.
