Evodiamine is a bioactive alkaloid that is specified as a biomarker for the quality assessment of Evodia rutaecarpa (E. rutaecarpa) and for traditional Chinese medicines containing this plant. We previously reported that quantitative structure–activity modeling indicated that evodiamine may cause cardiotoxicity. However, previous investigations have indicated that evodiamine has beneficial effects in patients with cardiovascular diseases and there are no previous in vitro or in vivo reports of evodiamine-induced cardiotoxicity. The present study investigated the effects of evodiamine on primary cultured neonatal rat cardiomyocytes in vitro, and on zebrafish in vivo. Cell viability was reduced in vitro, where evodiamine had a 24 h 50% inhibitory concentration of 28.44 µg/mL. Cells exposed to evodiamine also showed increased lactate dehydrogenase release and maleic dialdehyde levels, and reduced superoxide dismutase activity. In vivo, evodiamine had a 10% lethal concentration of 354 ng/mL and induced cardiac malfunction, as evidenced by changes in heart rate and circulation, and pericardial malformations. This study indicated that evodiamine could cause cardiovascular side effects involving oxidative stress. These findings suggest that cardiac function should be monitored in patients receiving preparations containing evodiamine.

Combining conventional drugs and traditional medicine may represent a useful approach to combating antibiotic resistance, which has become a serious threat to global public health. This study aimed to evaluate the potential synergistic interactions between Tanreqing (TRQ) injection, a commercial traditional Chinese medicine formula used for the treatment of upper respiratory tract infection, and selected antibiotics used against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MICs) of TRQ, vancomycin and linezolid against planktonic MRSA strain were determined by the broth microdilution method. The combined effects of TRQ and antibiotics were studied by the checkerboard method and the time-kill curve assay. The 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay was employed to determine the inhibitory effect of the test compounds alone and in combination against MRSA embedded in biofilms. MRSA strain was found to be susceptible to TRQ formula with MIC value 4125 μg/ml, while the MIC values for antibiotics, vancomycin and linezolid, were 2.5 μg/ml. The checkerboard analysis revealed that TRQ markedly enhanced activities of the tested antibiotics by reducing their MICs. In the time-kill analysis, TRQ at 1/2 × MIC in combination with vancomycin at 1/2 × MIC, as well as TRQ at 1/8 × MIC in combination with linezolid at 1/2 × MIC decreased the viable colonies by ≥2log10 CFU/ml, resulting in a potent synergistic effect against planktonic MRSA. In contrast to the tested antibiotics, which did not affect mature MRSA biofilms at subinhibitory concentrations, TRQ alone showed strong ability to disrupt preformed biofilms and induce biofilm cell death. The combination of TRQ with vancomycin or linezolid at sub-MIC concentrations resulted in a synergistic antibiofilm effect significantly higher than for each single agent. This study provides the first in vitro evidence on the synergistic effects of TRQ and vancomycin or linezolid against planktonic and biofilm MRSA, and revealed their optimal combination doses, thereby providing a rational basis for the combination therapies against MRSA.

Background: The molecular mechanism of quercetin in the prevention and treatment of AS has been widely reported. However, the microbial and metabolic characteristics of quercetin in AS treatment are still poorly understood. In this study, we aimed to explore the gut microbial and metabolic signatures of quercetin in AS treatment and conduct an integrative analysis on its biomechanism. Methods: An atherosclerosis mouse model was induced by a high cholesterol diet (HCD). The duration of the quercetin treatment was 12 weeks. We measured TC, TG, HDL and LDL for plasma biochemical analysis and TNF-α and IL-6 for plasma inflammatory analysis. Haematoxylin-eosin (HE) staining was conducted to evaluate the aortic structure and atherosclerosis. Bacterial DNA, which was extracted from mouse faeces, was identified by the V3−V4 regions of the 16S rRNA for microbiological analysis. The HeatMap package of BTtools was applied to visualize the data of the microbial difference matrix according to the OTU results. Fecal metabolites were assessed through LC-MS. Multivariate data analysis was conducted on the normalized data with SIMCA-P+. Significantly different metabolites were extracted based on the Pearson correlation coefficients at the level of P<0.05. Key significantly changed metabolites were screened from the intersection between metabolic signatures of the normal-model and model-quercetin groups. To investigate the biological function of quercetin on AS, we identified the differential metabolic signatures of the model vs. quercetin groups and performed KEGG analyses via MBROLE, MetaboAnalyst database. Results: Quercetin treatment for 12 weeks significantly reduced the levels of TC (P<0.001), TG (P<0.05), HDL (P<0.001), LDL (P<0.001), TNF-α (P<0.001) and IL-6 (P0.05) at the phylum level, and the genera Phascolarctobacterium and Anaerovibrio can be regarded as the key microbiota signatures of quercetin treatment. PLS-DA results further showed that these 18 faecal metabolites (clustered in 3 groups) had significant differences between the control, model and quercetin groups throughout the 12-day treatment. According to the quantitative analysis results, 32 key metabolic signatures were screened for quercetin treatment. The main pathway in quercetin treatment is primary bile acid biosynthesis, as 3α,7α,12α,26-tetrahydroxy-5β-cholestane (C27H48O4) was defined as the most important key metabolic signature. Conclusions: We explored the gut microbial and metabolic involvement of quercetin in AS treatment and suggest the association between AS and gut metabolic regulation.

Methicillin-resistant Staphylococcus aureus (MRSA) has posed a severe global health threat. In this study, we screened an antibiotic and non-antibiotic combination that provides a viable strategy to solve this issue by broadening the antimicrobial spectrum. We found that chenodeoxycholic acid (CDCA) could synergistically act with carbapenem antibiotics to eradicate MRSA-related infections. This synergy specifically targets MRSA and was also validated using 25 clinical MRSA strains using time–kill analysis. We speculated that the underlying mechanism was associated with the interaction of penicillin-binding proteins (PBPs). As a result, the synergistic efficiency of CDCA with carbapenems targeting PBP1 was better than that of β-lactams targeting PBPs. Moreover, we showed that CDCA did not affect the expression level of PBPs, but sensitized MRSA to carbapenems by disrupting the cell membrane. In our study, we have revealed a novel synergistic combination of antibiotics and non-antibiotics to combat potential bacterial infections.

Bacteria coordinate the response to oxidative stress through LysR-type transcriptional regulator (LTTR) OxyR. However, only fragmentary information on the regulation and function of OxyR has been gleaned in the opportunistic pathogen Pseudomonas aeruginosa. Here, we delineate the OxyR regulon using multi-omics analyses. OxyR is found to positively regulate several genes involved in quorum sensing (QS) and energy metabolism. OxyR is further involved in the negative regulation of amino acid transporters that was confirmed by metabolomics analysis. Finally, we uncover gltS, an OxyR regulon gene, could be used as a potential drug potentiation target. Altogether, our results confirm that, apart from its dominant role in defense against oxidative stress in P. aeruginosa, OxyR acts as a global regulator of QS, energy metabolism and amino acid homeostasis, but also serves as a model system to identify potential antibacterial target such as gltS.

Polygonum capitatum (PC) is an ethnomedicine with reported antibacterial and anti-inflammatory activities and has been clinically used in urinary tract infection (UTI)-related disorders. However, its in vivo exposure characteristics and metabolically associated therapeutic mechanisms in acute pyelonephritis (AP) remain insufficiently understood. To address this issue, this study aimed to evaluate the therapeutic effects of PC in an Escherichia coli (E. coli)-induced rat model of AP and to explore constituents and metabolic pathways associated with its activity. Different PC extracts were screened for antibacterial and anti-inflammatory activities, and the 70% ethanol extract was selected for further study. Seven major compounds were quantified by HPLC. In AP rats, the pharmacokinetic profiles of these compounds in plasma and the renal cortex were analyzed by microdialysis-coupled HPLC-MS/MS. Pharmacodynamic evaluation included urinary bacterial load, urinalysis, renal function, inflammatory cytokines, and renal histopathology. Exploratory PK–PD analysis, untargeted renal metabolomics, and targeted metabolomics of the tryptophan–kynurenine (Trp–Kyn) pathway were also performed. The 70% ethanol extract of PC exhibited the strongest antibacterial and anti-inflammatory activities. The total content of seven active compounds was 3.85%, with gallic acid being the predominant compound (3.42%). Pharmacokinetic analysis revealed that gallic acid, protocatechuic acid, methyl gallate, and quercitrin achieved relatively high systemic exposure and renal distribution. In AP rats, the pharmacokinetic profiles of several compounds were altered, with increased plasma exposure of protocatechuic acid, vanillic acid, ethyl gallate, and syringic acid, while protocatechuic acid also showed higher exposure in the renal cortex. PC treatment reduced urinary bacterial load, improved renal function and urinalysis parameters, alleviated histopathological injury, and decreased inflammatory mediator levels, particularly in renal tissue. Exploratory PK–PD correlations were observed between several compounds and selected pharmacodynamic indicators. Metabolomic analysis suggested disturbances in glycerophospholipid metabolism and the Trp–Kyn pathway in AP rats, some of which were partially reversed after PC treatment. PC showed antibacterial and anti-inflammatory effects in AP rats. Gallic acid, protocatechuic acid, methyl gallate, and quercitrin may be candidate constituents associated with the therapeutic effects of PC, while modulation of glycerophospholipid metabolism and the Trp–Kyn pathway may be involved in its action against AP. These findings provide preclinical pharmacological evidence supporting the therapeutic potential of PC in AP.