The combination of insulin and linezolid ameliorates Staphylococcus aureus pneumonia in individuals with diabetes via the TLR2/MAPKs/NLRP3 pathway.

Diabetes mellitus (DM) complicated with Staphylococcus aureus (S. aureus) infection lacks effective treatment strategies. In this study, we found that insulin combined with linezolid has potential to deal with the thorny problem. In vitro, our drug sensitivity assay, bacterial growth curve and hemolytic tests showed that a combination of insulin and linezolid exerted good antibacterial and anti-α-hemolysin activity, CCK8 experiment, glucose content and glycogen content determination showed that the combination of insulin and linezolid increased murine macrophage survival rate and reduced the extracellular glucose level of high glucose-treated MH-S cells and intracellular glycogen level, and Western blot showed that the combination inhibited TLR2/MAPKs/NLRP3-related inflammatory pathways in MH-S cells. The results of in vivo experiments showed that the combination therapy stabilized glucose level, remained body weight, ameliorated lung injury including improving pulmonary edema and decreasing lung wet/dry weight ratio, reduced the CFUs and inflammation in the lung tissue in a mouse model of diabetes with S. aureus pneumonia, and inhibited the expression of TLR2, MAPKs and NLRP3 inflammatory pathway. Overall, the combination of insulin and linezolid as autolytic inhibitor exhibited the effects of significant antibacterial and improving glucose level in vitro and in vivo, and also has an anti-inflammation activity via the TLR2/MAPKs/NLRP3 pathway, this paves the way for new treatments for diabetes mellitus complicated with S. aureus infection.

The combination of cloxacillin, thioridazine and tetracycline protects mice against Staphylococcus aureus peritonitis by inhibiting α-Hemolysin-induced MAPK/NF-κB/NLRP3 activation.

Staphylococcus aureus (S. aureus) infection is difficult to fight, previous experimental reports have demonstrated thioridazine (TZ) and tetracycline (TC) is an inhibitor of S. aureus efflux pump NorA and autolysin Atl, respectively, here, by means of molecular docking and molecular dynamics simulation, we observed that thioridazine (TZ) and tetracycline (TC) blocked the binding of substrates to NorA and Atl, respectively, and reduced their activities, and our antibacterial susceptibility test and three-dimensional checkerboard method showed that the three-drug combination of antibiotic cloxacillin (CXN), TZ and TC had a synergistic anti-Staphylococcal activity in vitro, and α-Hemolysin tests and scanning electron microscopy showed that the three-drug combination and the subinhibitory concentration of the combination significantly inhibited the secretion of α-hemolysin relative to the number of membrane-derived vesicles produced by S. aureus. Whereas Western blot and pharmacological inhibition assays showed that the three-drug combination significantly inhibited the expression of MAPK/NF-κB/NLRP3 proteins in macrophages induced with S. aureus α-hemolysin. In vivo, the drug combination significantly reduced bacterial colony-forming unit counts in the viscera of a mouse peritonitis model of S. aureus infection, therapy reduced the primary inflammatory pathology and the bacteria-stimulated release of cytokines such as IL-1ß and TNF-α, and inhibited the expression of MAPK/NF-κB/NLRP3 proteins in peritoneal macrophages. Thus, the combination of efflux pump inhibitor, autolysis inhibitor and antibiotic, is a novel anti-Staphylococcal and anti-inflammatory strategy who owning good antibacterial activity and significant inhibiting staphylococcal α-hemolysin and inflammation.

Biological effects of corosolic acid as an anti-inflammatory, anti-metabolic syndrome and anti-neoplasic natural compound.

Accumulating evidence has indicated that corosolic acid exerts anti-diabetic, anti-obesity, anti-inflammatory, anti-hyperlipidemic and anti-viral effects. More importantly, corosolic acid has recently attracted much attention due to its anticancer properties and innocuous effects on normal cells. Furthermore, the increasing proportion of obese and/or diabetic populations has led to an epidemic of non-alcoholic fatty liver disease (NAFLD), which frequently progresses to hepatocellular carcinoma (HCC). Evidence has indicated that NAFLD is closely associated with the development of HCC and comprises a high risk factor. The present review summarizes the anticancer effects of corosolic acid in vitro and in vivo, and its related molecular mechanisms. It also describes the inhibitory effects of corosolic acid on the progression of NAFLD and its associated molecular mechanisms, providing guidance for future research on corosolic acid in NAFLD-related HCC prevention and treatment. To the best of our knowledge, a review of corosolic acid as an anticancer agent has not yet been reported. Due to its multitargeted activity in cancer cells, corosolic acid exerts anticancer effects when administered alone, and acts synergistically when administered with chemotherapeutic drugs, even in drug-resistant cells. In addition, as a novel tool to treat metabolic syndromes, corosolic acid uses the same mechanism in its action against cancer as that used in the progression of NAFLD-related HCC. Therefore, corosolic acid has been suggested as an agent for the prevention and treatment of NAFLD-related HCC.

Natural compounds attenuate heavy metal-induced PC12 cell damage.

OBJECTIVES: To investigate the neuroprotective effects of six natural compounds (caffeine, gallic acid, resveratrol, epigallocatechin gallate [EGCG], L-ascorbic acid and alpha tocopherol [Vitamin E] on heavy metal-induced cell damage in rat PC12 cells. METHODS: In this in vitro experiment, rat PC12 cells were exposed to four heavy metals (CdCl2, HgCl2, CoCl2 and PbCl2) at different concentrations and cell apoptosis, necrosis and oxidative stress were assessed with and without the addition of the six natural compounds. RESULTS: The metals decreased cell viability but the natural compounds attenuated their effects on apoptosis, necrosis and reactive oxygen species (ROS) levels. Mitochondrial protein changes were involved in the regulation. CONCLUSION: Overall, the natural compounds did provide protection against the metal-induced PC12 cell damage. These data suggest that natural compounds may have therapeutic potential against metal-induced neurodegenerative disease.

Insulin-like growth factor-I activates NFκB and NLRP3 inflammatory signalling via ROS in cancer cells.

Previous studies have demonstrated that insulin-like growth factor-I (IGF-1) and reactive oxygen species (ROS) are involved in the development and progression of various cancers. However, their regulatory mechanism remains unknown. In this study, we treated cancer cells (HeLa, HepG2 and SW1116 cells) and normal cells (NCM-460) with IGF-1 at different concentrations and for different times and found that cancer cells produced large amounts of cytoplasmic ROS in cancer cells but not in normal cells. Further mechanistic analysis demonstrated that IGF-1 activated NFκB and NLRP3 inflammatory signalling in HeLa cells; systematic analysis indicated that IGF-1 activates NFκB and NLRP3, and the activation was cytosolic ROS- and NADPH oxidase 2 (NOX2)-dependent. Additionally, through coimmunoprecipitation experiments, we found that the IRS-1/COX2/mPGES-1/MAPKs/RAC2/NOX2 pathway nexus was involved in IGF-1-induced NFκB and NLRP3 production. Finally, we validated the regulatory mechanisms through IRS-1, mPGES-1 or NOX2 inhibition using their respective selective inhibitors or shRNA knockdown. Taken together, this is the first report on the mechanism by which IGF-1 activates NFκB and NLRP3 inflammatory signalling via ROS. These findings pave the way for an in-depth study of the role of IGF-1 and ROS in inflammation associated with the development and progression of cancer.

Targeting IRS-1/mPGES-1/NOX2 to inhibit the inflammatory response caused by insulin-like growth factor-I-induced activation of NF-κB and NLRP3 in cancer cells.

The levels of insulin-like growth factor-l (IGF-1) and reactive oxygen species (ROS) are abnormally elevated in various tumour tissues, and IGF-1 has been reported to be associated with the development and progression of inflammation in cancers. In this study, we found that IGF-1 activated nuclear factor-κB (NF-κB) and NLRP3 inflammatory signalling via IRS-1/mPGES-1/NOX2-regulated ROS. Additionally, in the B16-F10 tumour-bearing mouse model, the number of tumours, tumour growth, invasion of tissues and expression of proinflammatory factors in peripheral blood were significantly decreased by treatment with an inhibitor combination compared with those of the IGF-1 group. Taken together, targeting IRS-1/mPGES-1/NOX2 to inhibit inflammation related to NF-κB and NLRP3 is a potential strategy for controlling the development and progression of cancer.

Inhibition of Drug Resistance of Staphylococcus aureus by Efflux Pump Inhibitor and Autolysis Inducer to Strengthen the Antibacterial Activity of ß-lactam Drugs.

This study explored a potential treatment against methicillin-resistant Staphylococcus aureus (MRSA) infections that combines thioridazine (TZ), an efflux pump inhibitor, and miconazole (MCZ), an autolysis inducer, with the anti-microbial drug cloxacillin (CXN). In vitro, the combination treatment of TZ and MCZ significantly reduced 4096-fold (Σ (FIC) = 0.1 - 1.25) the MIC value of CXN against S. aureus. In vivo, the combination therapy significantly relieved breast redness and swelling in mice infected with either clinical or standard strains of S. aureus. Meanwhile, the number of bacteria isolated from the MRSA135-infected mice decreased significantly (p = 0.0427 < 0.05) after the combination therapy when compared to monotherapy. Moreover, the number of bacteria isolated from the mice infected with a reference S. aureus strain also decreased significantly (p = 0.0191 < 0.05) after the combination therapy when compared to monotherapy. The pathological changes were more significant in the CXN-treated group when compared to mice treated with a combination of three drugs. In addition, we found that combination therapy reduced the release of the bacteria-stimulated cytokines such as IL-6, IFN-γ, and TNF-α. Cytokine assays in serum revealed that CXN alone induced IL-6, IFN-γ, and TNF-α in the mouse groups infected with ATCC 29213 or MRSA135, and the combination of these three drugs significantly reduced IL-6, IFN-γ, and TNF-α concentrations. Also, the levels of TNF-α and IFN-γ in mice treated with a combination of three drugs were significantly lower than in the CXN-treated group. Given the synergistic antibacterial activity of CXN, we concluded that the combination of CXN with TZ, and MCZ could be developed as a novel therapeutic strategy against S. aureus.This study explored a potential treatment against methicillin-resistant Staphylococcus aureus (MRSA) infections that combines thioridazine (TZ), an efflux pump inhibitor, and miconazole (MCZ), an autolysis inducer, with the anti-microbial drug cloxacillin (CXN). In vitro, the combination treatment of TZ and MCZ significantly reduced 4096-fold (Σ (FIC) = 0.1 ­ 1.25) the MIC value of CXN against S. aureus. In vivo, the combination therapy significantly relieved breast redness and swelling in mice infected with either clinical or standard strains of S. aureus. Meanwhile, the number of bacteria isolated from the MRSA135-infected mice decreased significantly (p = 0.0427 < 0.05) after the combination therapy when compared to monotherapy. Moreover, the number of bacteria isolated from the mice infected with a reference S. aureus strain also decreased significantly (p = 0.0191 < 0.05) after the combination therapy when compared to monotherapy. The pathological changes were more significant in the CXN-treated group when compared to mice treated with a combination of three drugs. In addition, we found that combination therapy reduced the release of the bacteria-stimulated cytokines such as IL-6, IFN-γ, and TNF-α. Cytokine assays in serum revealed that CXN alone induced IL-6, IFN-γ, and TNF-α in the mouse groups infected with ATCC 29213 or MRSA135, and the combination of these three drugs significantly reduced IL-6, IFN-γ, and TNF-α concentrations. Also, the levels of TNF-α and IFN-γ in mice treated with a combination of three drugs were significantly lower than in the CXN-treated group. Given the synergistic antibacterial activity of CXN, we concluded that the combination of CXN with TZ, and MCZ could be developed as a novel therapeutic strategy against S. aureus.

Fosfomycin Protects Mice From Staphylococcus aureus Pneumonia Caused by α-Hemolysin in Extracellular Vesicles by Inhibiting MAPK-Regulated NLRP3 Inflammasomes.

α-Hemolysin (Hla) is a significant virulence factor in Staphylococcus aureus (S. aureus)-caused infectious diseases such as pneumonia. Thus, to prevent the production of Hla when treating S. aureus infection, it is necessary to choose an antibiotic with good antibacterial activity and effect. In our study, we observed that Fosfomycin (FOM) at a sub-inhibitory concentration inhibited expression of Hla. Molecular dynamics demonstrated that FOM bound to the binding sites LYS 154 and ASP 108 of Hla, potentially inhibiting Hla. Furthermore, we verified that staphylococcal membrane-derived vesicles (SMVs) contain Hla and that FOM treatment significantly reduced the production of SMVs and Hla. Based on our pharmacological inhibition analysis, ERK and p38 activated NLRP3 inflammasomes. Moreover, FOM inhibited expression of MAPKs and NLRP3 inflammasome-related proteins in S. aureus as well as SMV-infected human macrophages (MΦ) and alveolar epithelial cells. In vivo, SMVs isolated from S. aureus DU1090 (an isogenic Hla deletion mutant) or the strain itself caused weaker inflammation than that of its parent strain 8325-4. FOM also significantly reduced the phosphorylation levels of ERK and P38 and expression of NLRP3 inflammasome-related proteins. In addition, FOM decreased MPO activity, pulmonary vascular permeability and edema formation in the lungs of mice with S. aureus-caused pneumonia. Taken together, these data indicate that FOM exerts protective effects against S. aureus infection in vitro and in vivo by inhibiting Hla in SMVs and blocking ERK/P38-mediated NLRP3 inflammasome activation by Hla.