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Traditional Chinese medicine (TCM) injections have been used as valuable preparations of herbal medicines. However, minor quality variation of TCM injections in the storage and transportation often results in adverse drug reactions and adverse drug events. In this study, biothermal dynamic test combined with chemical analysis was applied to monitor the consistency and stability of TCM injections. Shuang- huang- lian freeze-dried powder for injection (SHLPI) was selected as a representative herbal injection. Ten batches of normal samples and nine batches of artificially abnormal samples were collected. High-performance liquid chromatography (HPLC) fingerprinting was frequently used to characterize the chemical composition of TCM injections. However, it could not monitor minor quality fluctuation of the samples under special conditions such as lighting, high temperature, and bacterial contamination. The biological activity of SHLPI on the growth of Staphylococcus aureus was detected and then analyzed with chemometric methods including similarity evaluation and partial least-squared discriminant analysis. The similarity of abnormal samples in HPLC fingerprinting was > 0.99, whereas most of the abnormal samples in biological fingerprinting was 0.943-0.652, demonstrating the greater discriminating ability of biological fingerprinting. Our study demonstrated that biological fingerprinting is effective to monitor the quality fluctuation of TCM injections and could improve the quality control of herbal medicines. [ABSTRACT FROM AUTHOR]

With the prevalence resistance of Staphylococcus aureus to antibacterial agents, developing novel antibacterial agents is urgent. Recently, plant extracts have got more focus. In this study, the power-time curves produced by S. aureus under the action of the four extracted fractions (PE, CHCl, EtOAc, and n-BuOH fractions) from the leaves of Dracontomelon dao were determined by microcalorimetry, and then some quantitative parameters, such as growth rate constant k, total heat output Q, maximum heat-output power P, and the appearance time t were obtained. By analyzing the parameters using principal component analysis, the anti- S. aureus effects of the four fractions were systematically evaluated and compared. Meanwhile, the total flavonoid contents in these fractions were analyzed. The results have evidenced that different fractions using various extraction solvents expressed various anti- S. aureus effects, and the inhibitory effects were presented in a flavonoid content-dependent manner. The EtOAc fraction with the highest total flavonoid content (41.86 %) expressed the strongest anti- S. aureus effect with half-inhibitory concentration (IC) of 83.93 μg mL, which might be applied as a novel antibacterial agent in practice for some infectious diseases. In addition, the microcalorimetric method should be strongly suggested in screening for novel antibacterial agents for fighting against pathogenic bacteria. [ABSTRACT FROM AUTHOR]

A challenging method for sterility test which was rapid and reliable had been established to assess the adaptability and robustness of the microbial under different conditions. There were material and energy metabolism or exchange with microbial on microcalorimetry, as a result this method can be served as one of the optimization of thermodynamics sterility test. Thermal power-time curves under various environmental conditions (including processing temperature, storage time, and drugs inhibition) were determined. Typical microbial growth thermal power-time curves were obtained. The curves were analyzed qualitatively and quantitatively by similarity values of bio-profiles and thermodynamics parameters, such as the exponential growth rate constant ( k), detection time ( T). The similarity showed that microbial growth curves of low processing temperature, short storage time (1 month), and Traditional Chinese Medicine injection (Shuanghuanglian, contained native compounds) inhibiting were match better with the normal than other circumstance. Thermodynamic parameters indicated that the microcalorimetric method could detect the positive bacteria within 18 h (less than 10 cfu), and more quickly identify the different states of the bacterium growth and metabolism than routine sterility. In conclusion, characterized by of the specific and strong two-dimensional information, microcalorimetry could supply thermograms as biological profiles to describe the microbial activity under different conditions, which were not only used as a rapid and reliable identification of microbial, but also as a method for sterility test of microcalorimetry optimization. [ABSTRACT FROM AUTHOR]

The antibacterial effect of Curcumin on Staphylococcus aureus growth was evaluated by microcalorimetry. The heat flow power-time curves and nine quantitative parameters of the S. aureus growth were applied to investigate the inhibitory effect with Curcumin. By analyzing these curves and some quantitative parameters using multivariate analytical methods, similarity analysis and principal component analysis, the antibacterial activity of Curcumin on S. aureus could be accurately evaluated from the change of the two main parameters, the second exponential growth rate constant k and the maximum heat flow power P. The main two thermal parameters played more important role in the evaluation: at low concentration (0-10.5 μg mL), Curcumin hardly influence the growth of S. aureus, while at high concentration (10.5-43.4 μg mL) it could notably inhibit the growth. All these illustrated that the antibacterial activity of Curcumin on S. aureus was enhanced with the increase of the concentration of this compound. This study might provide an useful method and idea accurately evaluate the antibacterial effects of Curcumin, which provides some useful methods for evaluate the nature antibacterial agents. [ABSTRACT FROM AUTHOR]

Using microcalorimetry, the characteristic metabolic heat flow power-time curves of S. aureus growth affected by Ursodesoxycholic acid and Hyodeoxycholic acid were measured at 37 °C. The thermal-kinetic parameters such as, growth rate constant k, the maximum power output ( P), the time corresponding to the maximum power output ( t), total heat-production Q, half inhibitory concentration of the drugs ( IC) were calculated from the growth curves. For both HDCA and UDCA, with the increasing of concentration, k, P, and Q decreased, meanwhile, k- c fit a linear equation, t was prolonged correspondingly. Principle component analysis, the results indicated t might be the main parameter in evaluating the antibacterial activity of HDCA and UDCA in microcalorimetric method. Combining with t and IC, the results revealed that the differences and trends of antibacterial activity of these bile acid derivatives were: HDCA > UDCA. Structure-activity relationship (SAR) analysis showed that the α-OH at C-3 and C-6 position at equal pace on the steroid nucleus enhanced the hydrophilicity of HDCA, which led to a stronger antibacterial effect than UDCA. In this study, a useful tool was provided to accurately evaluate the antibacterial effects of bile acid derivatives. The thermolysis curve recorded by microcalorimetry could provide a lot of kinetic and thermodynamic information for the study of growth process of living microbial, which could be helpful in the screening of high efficacy antibacterial agents. [ABSTRACT FROM AUTHOR]