20S-ginsenoside Rg3 inhibits the biofilm formation and haemolytic activity of Staphylococcus aureus by inhibiting the SaeR/SaeS two-component system.

Introduction. Staphylococcus aureus is a major cause of chronic diseases and biofilm formation is a contributing factor. 20S-ginsenoside Rg3 (Rg3) is a natural product extracted from the traditional Chinese medicine red ginseng.Gap statement. The effects of Rg3 on biofilm formation and haemolytic activity as well as its antibacterial mechanism against S. aureus have not been reported.Aim. This study aimed to investigate the effects of Rg3 on biofilm formation and haemolytic activity as well as its antibacterial action against clinical S. aureus isolates.Methodology. The effect of Rg3 on biofilm formation of clinical S. aureus isolates was studied by crystal violet staining. Haemolytic activity analysis was carried out. Furthermore, the influence of Rg3 on the proteome profile of S. aureus was studied by quantitative proteomics to clarify the mechanism underlying its antibacterial action and further verified by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR).Results. Rg3 significantly inhibited biofilm formation and haemolytic activity in clinical S. aureus isolates. A total of 63 with >1.5-fold changes in expression were identified, including 34 upregulated proteins and 29 downregulated proteins. Based on bioinformatics analysis, the expression of several virulence factors and biofilm-related proteins, containing CopZ, CspA, SasG, SaeR/SaeS two-component system and SaeR/SaeS-regulated proteins, including leukocidin-like protein 2, immunoglobulin-binding protein G (Sbi) and fibrinogen-binding protein, in the S. aureus of the Rg3-treated group was downregulated. RT-qPCR confirmed that Rg3 inhibited the regulation of SaeR/SaeS and decreased the transcriptional levels of the biofilm-related genes CopZ, CspA and SasG.Conclusions. Rg3 reduces the formation of biofilm by reducing cell adhesion and aggregation. Further, Rg3 can inhibit the SaeR/SaeS two-component system, which acts as a crucial signal transduction system for the anti-virulence activity of Rg3 against clinical S. aureus isolates.

The Mechanism of Action of Ginkgolic Acid (15:1) against Gram-Positive Bacteria Involves Cross Talk with Iron Homeostasis.

With the increasing reports of community-acquired and nosocomial infection caused by multidrug-resistant Gram-positive pathogens, there is an urgent need to develop new antimicrobial agents with novel antibacterial mechanisms. Here, we investigated the antibacterial activity of the natural product ginkgolic acid (GA) (15:1), derived from Ginkgo biloba, and its potential mode of action against the Gram-positive bacteria Enterococcus faecalis and Staphylococcus aureus. The MIC values of GA (15:1) against clinical E. faecalis and S. aureus isolates from China were ≤4 and ≤8 µg/mL, respectively, from our test results. Moreover, GA (15:1) displayed high efficiency in biofilm formation inhibition and bactericidal activity against E. faecalis and S. aureus. During its inhibition of the planktonic bacteria, the antibacterial activity of GA (15:1) was significantly improved under the condition of abolishing iron homeostasis. When iron homeostasis was abolished, inhibition of planktonic bacteria by GA (15:1) was significantly improved. This phenomenon can be interpreted as showing that iron homeostasis disruption facilitated the disruption of the functions of ribosome and protein synthesis by GA (15:1), resulting in inhibition of bacterial growth and cell death. Genetic mutation of ferric uptake regulator (Fur) led to GA (15:1) tolerance in in vitro-induced resistant derivatives, while overexpression of Fur led to increased GA (15:1) susceptibility. Additionally, GA (15:1) significantly decreased the bacterial loads of S. aureus strain USA300 in the lung tissues of mice in a pneumonic murine model. Conclusively, this study revealed an antimicrobial mechanism of GA (15:1) involving cross talk with iron homeostasis against Gram-positive pathogens. In the future, the natural product GA (15:1) might be applied to combat infections caused by Gram-positive pathogens. IMPORTANCE The increasing emergence of infectious diseases associated with multidrug-resistant Gram-positive pathogens has raised the urgent need to develop novel antibiotics. GA (15:1) is a natural product derived from Ginkgo biloba and possesses a wide range of bioactivities, including antimicrobial activity. However, its antibacterial mechanisms remain unclear. Our current study found that the function of ferric uptake regulator (Fur) was highly correlated with the antimicrobial activity of GA (15:1) against E. faecalis and that the antibacterial activity of GA (15:1) could be strengthened by the disruption of iron homeostasis. This study provided important insight into the mode of action of GA (15:1) against Gram-positive bacteria and suggested that GA (15:1) holds the potential to be an antimicrobial treatment option for infection caused by multidrug-resistant Gram-positive pathogens.

Network Pharmacology Study on Molecular Mechanisms of Zhishi Xiebai Guizhi Decoction in the Treatment of Coronary Heart Disease.

BACKGROUND: Coronary heart disease is characterized by the formation of arterial plaque. If not taken seriously, it will cause serious consequences such as myocardial infarction and heart failure. Zhishi Xiebai Guizhi Decoction first appeared in "Synopsis of Prescriptions of the Golden Chamber" and is a representative prescription for the treatment of coronary heart disease. This study aims to explain the mechanism of Zhishi Xiebai Guizhi Decoction in the treatment of coronary heart disease through network pharmacology and clinical trials. METHODS: We first identified the core compounds of Zhishi Xiebai Guizhi Decoction and their potential targets through TCMSP. Then, We analyzed the molecular targets of Zhishi Xiebai Guizhi Decoction in coronary heart disease with OMIM and GeneCards databases. After the common targets were screened out, we manage to figure out the pathways of these target genes through STRING. Finally, we verify the treatment results in clinical trials. RESULTS: Through network pharmacology analysis, we discovered that several core compounds of Zhishi Xiebai Guizhi Decoction have anti-inflammatory effects and are of great significance to treatment of cardiovascular diseases. The mechanism may be closely related to PPARγ, inflammation, TNF signaling pathway, AMPK signaling pathway, and PI3K-Akt signaling pathway. Clinical trials have also proved the key role of inflammation. CONCLUSIONS: Zhishi Xiebai Guizhi Decoction may play a role in treating coronary heart disease by activating PPARγ. TNF signaling pathway, AMPK signaling pathway, and PI3K-Akt signaling pathway are potential mechanisms as well. The application of network pharmacology can provide a novel method for the research of Chinese herbal medicine. We hope that Zhishi Xiebai Guizhi Decoction will be recognized as a complementary or alternative treatment for coronary heart disease.

Se-Methylselenocysteine (SMC) Improves Cognitive Deficits by Attenuating Synaptic and Metabolic Abnormalities in Alzheimer's Mice Model: A Proteomic Study.

Se-methylselenocysteine (SMC) is a major selenocompound in selenium (Se) enriched plants and has been found to ameliorate neuropathology and cognitive deficits in triple-transgenic mice model of Alzheimer's disease (3 × Tg-AD mice). To explore the underlying molecular mechanisms, the present study is designed to elucidate the protein changes in the cortex of SMC-treated 3 × Tg-AD mice. After SMC supplementation, proteomic analysis revealed that 181, 271, and 41 proteins were identified as differentially expressed proteins (DEPs) between 3 × Tg-AD mice vs wild type (AD/WT group), SMC-treated AD mice vs AD (AD + SMC/AD), and AD + SMC/WT group, respectively. Among these, 138 proteins in the diseased group were reversed by SMC treatment. The DEPs in AD/WT group and AD + SMC/AD group were mainly related to metabolism, synapses, and antioxidant proteins, while their levels were decreased in AD mice but up-regulated after treating with SMC. In addition, we found reduced ATP levels and destroyed synaptic structures in the AD mice brains, which were significantly ameliorated upon SMC treatment. Our study suggests that energy metabolism disorders, abnormal amino acid metabolism, synaptic dysfunction, and oxidative stress may be the key pathogenic phenomena of AD. SMC reversed the expression of proteins associated with them, which might be the main mechanism of its intervention in AD.

Relationships between zooplankton biomass and environmental factors of Xiaoxingkai Lake in northeastern China.

Zooplankton biomass and water environment factors in Xiaoxingkai Lake were investigated, and the correlation between biomass and water environment factors was performed using the Pearson correlation analysis and redundancy analysis (RDA). The results showed that the highest zooplankton biomass was recorded in summer and the lowest in spring. Water depth, transparency (SD), electric conductivity, and total nitrogen were the highest in spring, while temperature and total phosphorus were the highest in summer. The values of pH and turbidity were the highest in autumn, while chloride ion and chlorophyll a were the highest in winter. During the spring period, Protozoa were positively correlated with conductivity, transparency (SD), and total nitrogen. While Rotifera demonstrated a strong correlation with turbidity, pH, temperature, and total phosphorus in summer and autumn seasons, and Cladocera were correlated with water depth. There were negative correlations of chlorophyll a and chlorine on Copepoda during the winter. RDA results displayed that zooplankton had strong relationships with the physicochemical characteristics in Xiaoxingkai Lake.

Transcriptomic Insights into the Response of the Olfactory Bulb to Selenium Treatment in a Mouse Model of Alzheimer's Disease.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by the presence of extracellular senile plaques primarily composed of Aß peptides and intracellular neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau proteins. Olfactory dysfunction is an early clinical phenotype in AD and was reported to be attributable to the presence of NFTs, senile Aß plaques in the olfactory bulb (OB). Our previous research found that selenomethionine (Se-Met), a major form of selenium (Se) in organisms, effectively increased oxidation resistance as well as reduced the generation and deposition of Aß and tau hyperphosphorylation in the olfactory bulb of a triple transgenic mouse model of AD (3×Tg-AD), thereby suggesting a potential therapeutic option for AD. In this study, we further investigated changes in the transcriptome data of olfactory bulb tissues of 7-month-old triple transgenic AD (3×Tg-AD) mice treated with Se-Met (6 µg/mL) for three months. Comparison of the gene expression profile between Se-Met-treated and control mice revealed 143 differentially expressed genes (DEGs). Among these genes, 21 DEGs were upregulated and 122 downregulated. The DEGs were then annotated against the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The results show that upregulated genes can be roughly classified into three types. Some of them mainly regulate the regeneration of nerves, such as Fabp7, Evt5 and Gal; some are involved in improving cognition and memory, such as Areg; and some are involved in anti-oxidative stress and anti-apoptosis, such as Adcyap1 and Scg2. The downregulated genes are mainly associated with inflammation and apoptosis, such as Lrg1, Scgb3a1 and Pglyrp1. The reliability of the transcriptomic data was validated by quantitative real time polymerase chain reaction (qRT-PCR) for the selected genes. These results were in line with our previous study, which indicated therapeutic effects of Se-Met on AD mice, providing a theoretical basis for further study of the treatment of AD by Se-Met.

Selenium positively affects the proteome of 3 × Tg-AD mice cortex by altering the expression of various key proteins: unveiling the mechanistic role of selenium in AD prevention.

Selenium (Se) deficiency is believed to be involved in pathogenesis of Alzheimer's disease (AD) due to failure of antioxidant system. Its supplementation may restore the antioxidant system and compensate the impairments caused by AD. Present study reveals the effect of Se on the proteomic changes in cortex within triple transgenic male AD mice (3 × Tg-AD) after 4 months sodium selenate supplementation. Using iTRAQ comparative proteomics approach, 142 proteins found significant alterations with 96 down-regulated and 46 up-regulated proteins in the cortices of AD mice in comparison with the wild non-transgenic type mice. On treatment with sodium selenate, 41 proteins showed reverse expression, that is, thirty three proteins were down-regulated in AD mice but up-regulated in selenate treated AD mice while eight up-regulated proteins in AD mice showed lower expression in selenate treated mice. OmicsBean bioinformatics analysis revealed that Se positively affected the proteins vital in biological process, structural cores, and molecular functions, which include metabolic proteins, structural proteins, signaling molecules, oxidative stress balancers, and proteosomal degradation proteins. Results of mass spectrometry (MS) were further confirmed by Western blot analysis of five important proteins, prompting the authenticity of the MS results. This paper fills the protein-based molecular gap between AD and Se-treatment, and it provides a full view of Se in reversing the change of cortical protein levels during AD formation.

Effect of Sodium Selenate on Hippocampal Proteome of 3×Tg-AD Mice-Exploring the Antioxidant Dogma of Selenium against Alzheimer's Disease.

Selenium (Se), an antioxidant trace element, is an important nutrient for maintaining brain functions and is reported to be involved in Alzheimer's disease (AD) pathologies. The present study has been designed to elucidate the protein changes in hippocampus of 3×Tg-AD mice after supplementing sodium selenate as an inorganic source of selenium. By using iTRAQ proteomics technology, 113 differentially expressed proteins (DEPs) are found in AD/WT mice with 37 upregulated and 76 downregulated proteins. Similarly, in selenate-treated 3×Tg-AD (ADSe/AD) mice, 115 DEPs are found with 98 upregulated and 17 downregulated proteins. The third group of mice (ADSe/WT) showed 75 DEPs with 46 upregulated and 29 downregulated proteins. Among these results, 42 proteins (40 downregulated and 2 upregulated) in the diseased group showed reverse expression when treated with selenate. These DEPs are analyzed with different bioinformatics tools and are found associated with various AD pathologies and pathways. Based on their functions, selenate-reversed proteins are classified as structural proteins, metabolic proteins, calcium regulating proteins, synaptic proteins, signaling proteins, stress related proteins, and transport proteins. Six altered AD associated proteins are successfully validated by Western blot analysis. This study shows that sodium selenate has a profound effect on the hippocampus of the triple transgenic AD mice. This might be established as an effective therapeutic agent after further investigation.

The role of α-zearalanol in reversing bone loss induced by ovarian hormone deficiency in rats.

To assess the ability of α-zearalanol (α-ZAL) to prevent bone loss in an ovariectomized (OVX) rat model of osteoporosis, α-ZAL was administered intragastrically to rats. After 35 days, the total body bone mineral density (BMD) was assessed in all rats. All sections were processed for immunohistochemistry and hematoxylin and eosin staining. One-way ANOVA and an LSD multiple-range test were used to determine the significant differences between groups. BMD was lower in the OVX and OVX + α-ZAL high-dose (OVX + High) groups compared to the sham-operated (Sham), OVX + 17ß-ethinylestradiol (OVX + E(2)), OVX + α-ZAL medium-dose (OVX + Medium) and OVX + α-ZAL low-dose (OVX + Low) groups (P < 0.05). Clear bone trabeculae arrangements were observed in the OVX + E(2,) OVX + Medium and OVX + Low groups. The expressions of bone morphogenetic proteins and basic fibroblast growth factor were up-regulated in the OVX + E(2), OVX + Medium and OVX + Low groups compared to the OVX and OVX + High groups (P < 0.05). The OVX + E(2), OVX + Medium and OVX + Low groups showed lower levels of bone Gla protein, bone alkaline phosphatase, tartrate-resistant acid phosphatase and tumor necrosis factor α expressions than the OVX and OVX + High groups (P < 0.05). The administration of α-ZAL to ovariectomized rats reverses bone loss and prevents osteoporosis.

Protective effects of Polygonatum sibiricum polysaccharide on ovariectomy-induced bone loss in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: To assess the ability of traditional Chinese medicine Polygonatum sibiricum polysaccharide to prevent bone loss in the ovariectomized rat. MATERIALS AND METHODS: PSP was administered intragastrically to the rats. After 35 days, the total body bone mineral density (BMD) was assessed in all of the rats. All sections were processed for immunohistochemistry and hematoxylin-eosin staining (H.E.). RESULTS: BMD was lower in the ovariectomized group (OVX, 0.163 g/cm(2)), the group that received a moderate dose of PSP on OVX animals (OVX+MP, 0.163 g/cm(2)) and the group that received a low dose of PSP on OVX animals (OVX+LP, 0.162 g/cm(2)) than in the sham-operated group (SHAM, 0.180 g/cm(2)), the OVX+E(2) group (OVX+E(2), 0.176 g/cm(2)) and the group that received a high dose of PSP on OVX animals (OVX+HP, 0.174 g/cm(2)) (P<0.05). Clear arrangements of bone trabeculae were observed in the OVX+E(2) and OVX+HP. The expression of bone morphogenetic proteins (BMP) and basic fibroblast growth factor (bFGF) in the OVX, OVX+MP and OVX+LP was down regulated compared to the SHAM, OVX+E(2) and OVX+HP (P<0.05). The rats in the OVX+E(2) and OVX+HP had lower levels of bone Gla protein (BGP), bone alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRAP) and tumor necrosis factor α(TNF-α) expression than the rats in the OVX, OVX+MP and OVX+LP (P<0.05). CONCLUSION: This experiment demonstrates that the administration of PSP to ovariectomized rats reverses bone loss and prevents osteoporosis.