The antimicrobial activities of sucrose monolaurate and a novel ester, lactose monolaurate (LML), were tested. Gram-positive bacteria were more susceptible than Gram-negative bacteria to both esters. The minimal bactericidal concentrations of LML were 5 to 9.5 mM for Listeria monocytogenes isolates and 0.2 to 2 mM for Mycobacterium isolates.
Metabonomic analysis has been widely used in the study of traditional Chinese medicine (TCM) syndromes.In this paper, dynamic changes of the metabolic network during the evolution of a syndrome based on the toxic heat and blood stasis syndrome (THBSS) rat model have been elucidated for the first time. It was found that the metabolic trajectories could characterize three stages during THBSS evolution: the metabolic disturbance at 2-5 h, 8-12 h and 24-48 h could reflect the status of the excessive heat and little blood stasis stage, the coexistence of heat and blood stasis stage and the blood stasis stage respectively. The obtained dynamic metabolic network revealed the mechanism of THBSS progression: the inhibition of nicotinate and nicotinamide metabolism may lead to the activation of SIRT1 producing an inflammatory response, which then results in the disorder of energy metabolism and amino acid metabolism, and eventually the blood stasis appears. Nine involved metabolic pathways were found, among which the nicotinate and nicotinamide metabolism and histidine metabolism closely related to the occurrence of the inflammatory response in the early stage and blood stasis in the later stage of THBSS respectively.The former one, which is not reported in other blood stasis syndromes, might be the characteristic pathway of THBSS. This study firstly reveals the essence of THBSS progression, which is conducive to the diagnosis and pharmacotherapeutics of THBSS and related diseases, and also provides a new way to study TCM syndrome evolution.
A persistent need exists for effective treatment agents for mycobacterial infections. This research investigated the effectiveness of the Hypericum perforatum herb (commonly known as St John's wort; SJW) in its growth inhibition of mycobacteria. A SJW extract was effective at inhibiting five nonpathogenic Mycobacterium isolates and Bacillus subtilis, but not Escherichia coli. Quantitative studies of concentration sensitivity to the SJW extract were performed with minimal bactericidal concentrations (MBC) ranging from 0.33 to 2.66 mg extract/mL. The SJW compounds hyperforin (Hfn), hypericin (Hpn), and pseudohypericin (Phn) were quantified in the extract using HPLC. The SJW extract solution of 133 mg extract/mL used in this study contained 2.3 mg Hfn/mL, 0.8 mg Hpn/mL, and 2.1 mg Phn/mL. Purified Hfn, Hpn, and Phn were tested for inhibitory activity against Mycobacterium JLS (M. JLS) at similar concentrations used in the crude extract. While Hfn was inhibitory at 46 µg/mL, none of the purified SJW constituents were bactericidal at concentrations corresponding to SJW treatments. Scanning electron microscopy (SEM) analysis of SJW-treated M. JLS cells showed changes in cell surface morphology.
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