ABSTRACT
Staphylococcus aureus (S. aureus) is a common pathogenic bacterium that causes various diseases in both humans and animals. With the increased prevalence of methicillin-resistant S. aureus, the therapeutic effects of commonly used antibiotics are limited against S. aureus infection. Novel treatment strategies and new antibiotics are needed urgently to address this concern. Many studies have shown that virulence factors secreted from S. aureus play vital roles in their pathogenic processes. Alpha-hemolysin (Hla), an important exotoxin in S. aureus, is one such virulence factor that increases sensitivity of multiple host cells to S. aureus resulting in various diseases. Eriodictyol is a flavonoid compound that exists in many fruits and vegetables. In this study, eriodictyol was demonstrated to inhibit the expression of Hla by hemolysis assays, western blotting, and RT-qPCR at the sub-minimal inhibitory concentration. In live/dead and cytotoxicity assays, the results showed that eriodictyol protected A549 cells against Hla-induced injury in a dose-dependent manner. The minimal inhibitory concentration of eriodictyol against S. aureus was 512 µg/mL. Eriodictyol can downregulate S. aureus Hla at both the expressional and transcriptional levels without affecting S. aureus growth. In addition, cell assays had proved that eriodictyol could protect A549 cells against Hla damage. Eriodictyol could therefore have the potential to treat S. aureus infection targeting Hla.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Toxins/toxicity , Flavanones/pharmacology , Hemolysin Proteins/drug effects , Hemolysin Proteins/toxicity , Lung Injury/prevention & control , Staphylococcus aureus/drug effects , A549 Cells/drug effects , Bacterial Toxins/genetics , Bacterial Toxins/metabolism , Down-Regulation/drug effects , Gene Expression Regulation, Bacterial/drug effects , Hemolysin Proteins/genetics , Hemolysin Proteins/metabolism , Hemolysis , Humans , Lung Injury/microbiology , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/metabolism , Microbial Sensitivity Tests , Pneumonia, Staphylococcal/microbiology , Pneumonia, Staphylococcal/pathology , Pneumonia, Staphylococcal/prevention & control , Staphylococcus aureus/growth & development , Staphylococcus aureus/metabolism , Staphylococcus aureus/pathogenicity , Virulence Factors/metabolismABSTRACT
Staphylococcus aureus (S. aureus) is a common gram-positive bacterium that causes serious infections in humans and animals. With the continuous emergence of methicillin-resistant S. aureus (MRSA) strains, antibiotics have limited efficacy in treating MRSA infections. Accordingly, novel agents that act on new targets are desperately needed to combat these infections. S. aureus alpha-hemolysin plays an indispensable role in its pathogenicity. In this study, we demonstrate that sclareol, a fragrant chemical compound found in clary sage, can prominently decrease alpha-hemolysin secretion in S. aureus strain USA300 at sub-inhibitory concentrations. Hemolysis assays, western-blotting, and RT-PCR were used to detect the production of alpha-hemolysin in the culture supernatant. When USA300 was co-cultured with A549 epithelial cells, sclareol could protect the A549 cells at a final concentration of 8 µg/ml. The protective capability of sclareol against the USA300-mediated injury of A549 cells was further shown by cytotoxicity assays and live/dead analysis. In conclusion, sclareol was shown to inhibit the production of S. aureus alpha-hemolysin. Sclareol has potential for development as a new agent to treat S. aureus infections.
ABSTRACT
As a comprehensive, quantifiable identification method based on the chemical composition information of traditional Chinese medicine (TCM), the fingerprint of traditional Chinese medicine has become an internationally recognized effective way to control the quality of natural medicine. Chemical pattern recognition in traditional Chinese medicines is an important breakthrough for the infiltration between fuzzy and pharmaceutical sciences, has been used in the field of quality assessment and control for traditional Chinese medicine. It has solved the problem of comprehensive analysis with multi-dimensional information, and gradually been accepted by more researchers to in-depth study in the further. With the development of modern chemical analysis and computer techniques, there are more technologies were applied to the establishment of fingerprints of traditional Chinese medicine, more chemometric methods have been applied to the data processing of TCM fingerprint, and more quality identification and assessment for TCM to be achieved. And the technology has matured and achieved a lot. In this paper, we make a review for the chemical pattern recognition in traditional Chinese medicines since it be invented, provide a reference for the further research.
Subject(s)
Drugs, Chinese Herbal , Chemistry , Medicine, Chinese Traditional , MethodsABSTRACT
Bupleurum chinense is a commonly used Chinese medicinal material, which has been used medicinally in China for over 2000 years, the development of it is of great value. There have been great advances of studies on its embryology and seed biology in recent years. In this paper, we make a review of the growth of its embryo and fruit, the characteristics of dormancy and storage and the germination of its seed. Besides, we summarize the reasons of its low germination rate and the achievements in improving the situation, for the purpose of providing reference in research on seed physiology of B. chinense.
Subject(s)
Bupleurum , Chemistry , Physiology , Drugs, Chinese Herbal , Plant Dormancy , Seeds , Chemistry , PhysiologyABSTRACT
<p><b>OBJECTIVE</b>To compare the agronomic characters, HPLC fingerprints, the content of main component and amino acid between erective and creepy Ophiopogon japonicus of Sichuan.</p><p><b>METHOD</b>Agronomic characters were measured by conventional methods; HPLC was applied on a C18 column with CH3OH-CH3CN-2% CH2COOH solution by gradient elution, quercetin was used as the internal standard reference, the contents of total saponins, flavone and polysaccharide were determined by UV spectrophotometry and amino acid was determined by automatic amino acid analyzer.</p><p><b>RESULT</b>There were extremely significant differences in the most agronomic characters between erective and creepy O. japonicus of Sichuan. The yield per plant was closely relevant to the roots number and the fresh weight of aerial part. The differences were not significant both in 69 common peaks and 23 uncommon peaks in HLPC fingerprints and the content of main component between erective and creepy O. japonicus.</p><p><b>CONCLUSION</b>There is no obvious difference in chemistry component between the two types of O. japonicus. The yield per plant was closely relevant to the roots number and the fresh weight of aerial part. In cultivation it is appropriate to choose the creepy O. japonicus.</p>
