Evaluation of the in vitro and intracellular efficacy of new monosubstituted sulfonylureas against extensively drug-resistant tuberculosis

Using Pharmacoepidemiology to Examine the Interplay of Sulfonylureas and Infection Risk in Patients With Diabetes Mellitus

Sulfonylureas (SU) are commonly prescribed as oral hypoglycemic agents for the management of diabetes mellitus (DM). We postulated that SU possess antimicrobial properties due to their structural resemblance to the antimicrobial agent sulfamethoxazole. Using data from Taiwan's National Health Insurance Research Database, we enrolled patients diagnosed with DM between 2000 and 2013 and followed them for a three-year period. Patients who consistently used SU were categorized into the SU cohort, while those who had never used SU formed the non-sulfonylurea (non-SU) cohort. The primary study endpoints were diagnoses of pneumonia and urinary tract infections (UTIs). Within the database, we identified a total of 15,458,554 patients with DM, with 754,601 (4.88%) in the SU cohort and 2,244,436 (14.52%) in the non-SU cohort. After individual matching based on age, gender, index day, and propensity score of comorbidities, we included 663,056 patients in each cohort. The cumulative incidence of pneumonia and UTI was 29,239 (4.41%) and 60,733 (9.16%) in the SU cohort, respectively, and 24,599 (3.71%) and 56,554 (8.53%) in the non-SU cohort, respectively. Our findings indicated that the use of SU increased the risk of pneumonia (1.26-1.60 times) and UTI (1.13-1.22 times), while also potentially offsetting the protective effects of metformin. This pharmacoepidemiological study represents a concerted effort to assess latent drug properties that may have a significant impact on the clinical management of patients with DM.

Zinc oxide nanoparticles have biphasic roles on Mycobacterium-induced inflammation by activating autophagy and ferroptosis mechanisms in infected macrophages

The ability of zinc oxide nanoparticles (ZnONPs) to induce bacteriostasis in Mycobacterium tuberculosis (M. tb) and their roles in regulating the pathogenic activities of immune cells have been reported previously, but the specific mechanisms underlying these regulatory functions remain unclear. This work aimed to determine how ZnONPs play the antibacterial role against M. tb. In vitro activity assays were employed to determine the minimum inhibitory concentrations (MICs) of the ZnONPs against various strains of M. tb (BCG, H37Rv, and clinical susceptible MDR and XDR strains). The ZnONPs had MICs of 0.5-2 mg/L against all tested isolates. In addition, changes in the expression levels of autophagy and ferroptosis-related markers in BCG-infected macrophages exposed to ZnONPs were measured. BCG-infected mice that were administered ZnONPs were used to determine the ZnONPs functions in vivo. ZnONPs decreased the number of bacteria engulfed by the macrophages in a dose-dependent manner, while different doses of ZnONPs also affected inflammation in different directions. Although ZnONPs enhanced the BCG-induced autophagy of macrophages in a dose-dependent manner, only low doses of ZnONPs activated autophagy mechanisms by increasing the levels of pro-inflammatory factors. The ZnONPs also enhanced BCG-induced ferroptosis of macrophages at high doses. Co-administration of a ferroptosis inhibitor with the ZnONPs improved the anti-Mycobacterium activity of ZnONPs in an in vivo mouse model and alleviated acute lung injury caused by ZnONPs. Based on the above findings, we conclude that ZnONPs may act as potential antibacterial agents in future animal and clinical studies.

Pd-Catalyzed Carbonylative Synthesis of 4H-Benzo[d][1,3]Oxazin-4-Ones Using Benzene-1,3,5-Triyl Triformate as the CO Source

A facile synthesis of 4H-benzo[d][1,3]oxazin-4-one derivatives by Pd-catalyzed carbonylative cross-coupling between N-(ortho-bromoaryl)amides and benzene-1,3,5-triyl triformate (TFBen) was developed. This procedure does not require the toxic and flammable gas CO as the carbonyl source and tolerates a wide scope of functional groups. Remarkably, 4H-benzo[d][1,3]oxazin-4-ones incorporated to natural products and drugs can be constructed by this method.

Clinical Characteristics and Prognostic Analysis of Patients With Pulmonary Tuberculosis and Type 2 Diabetes Comorbidity in China: A Retrospective Analysis

Background: Tuberculosis (TB) is one of the leading communicable diseases, with significant morbidity and mortality. Diabetes can increase the risk of developing TB and the related adverse outcomes. This study retrospectively analyzed the clinical characteristics and prognosis of patients with pulmonary TB and type 2 diabetes comorbidity.

Methods: About 282 cases with pulmonary TB and type 2 diabetes comorbidity were identified from West China Hospital between January 1, 2010, and December 31, 2016, and were followed up for at least 3 years. We further used Kaplan–Meier methods and COX regression analysis to identify the influence factors for all-cause death.

Results: Compared to the survival patients, patients who died were older, exhibited significantly lower albumin and hemoglobin levels, but higher Charlson Comorbidity Index (CCI) score at admission, and had a lower usage rate of metformin. The all-cause mortality rates at 1 and 5 years were 5.67 and 20.59%, separately. For 1-year all-cause death, higher albumin level (HR = 0.90, 95% CI: 0.81–0.99) was the independently protective factor, but older age (HR = 1.07, 95% CI: 1.01–1.13) and CCI score ≥3 (HR = 6.77, 95% CI: 1.40–32.69) were the independent risk factors. For long-term all-cause death, higher albumin level (HR = 0.94, 95% CI: 0.88–1.00), the use of metformin (HR = 0.21, 95% CI: 0.07–0.59), insulin (HR = 0.27, 95% CI: 0.10–0.74), or sulfonylureas (HR = 0.23, 95% CI: 0.07–0.74) were the independently protective factors, but older age (HR = 1.03, 95% CI: 1.00–1.07) and CCI score ≥3 (HR = 7.15, 95% CI: 2.56–19.92) were the independent risk factors.

Conclusions: The lower albumin level, older age, and CCI score ≥3 were predictors of all-cause death in patients with pulmonary TB and type 2 diabetes comorbidity. In the long run, patients who use metformin, insulin, or sulfonylureas as hypoglycemic agents may have a lower incidence of death.

The chemical mechanisms of the enzymes in the branched-chain amino acids biosynthetic pathway and their applications

l-Valine, l-isoleucine, and l-leucine are three key proteinogenic amino acids, and they are also the essential amino acids required for mammalian growth, possessing important and to some extent, special physiological and biological functions. Because of the branched structures in their carbon chains, they are also named as branched-chain amino acids (BCAAs). This review will highlight the advance in studies of the enzymes involved in the biosynthetic pathway of BCAAs, concentrating on their chemical mechanisms and applications in screening herbicides and antibacterial agents. The uses of some of these enzymes in lab scale organic synthesis are also discussed.

α-Glucosidase Inhibitor Can Effectively Inhibit the Risk of Tuberculosis in Patients with Diabetes: A Nested Case-Control Study

Diabetes mellitus (DM) and tuberculosis (TB) are major public health and economic burdens. DM increases Mycobacterium tuberculosis (M.tb) infection rates and treatment durations. This study evaluated the relationship between five classes of oral DM medications and TB infection risk in DM patients. We used longitudinal records from the Taiwan Longitudinal Health Insurance Research Database. DM patients were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 250 and A code A181. TB patients were identified using ICD-9-CM code 010.x-017.x. Oral DM medications were divided into five classes: sulfonylureas, biguanides, meglitinides, α-glucosidase inhibitors (AGIs), and thiazolidinediones. Users were classified as nonusers, low-concentration users, and high-concentration users. The incidence rate ratio (IRR) was derived using multivariate Poisson regression to calculate the relative risk of TB infection. DM patients using low- and high-concentration AGIs had significantly lower TB infection risks compared with nonusers. The IRRs of the sulfonylureas and AGI users were [CI] 0.693-0.948) and (95% CI 0.651-0.995), respectively. The other four classes of medications exhibited no significant effect on TB infection risk in DM patients. Furthermore, DM patients using high-concentration AGIs had a significantly lower TB infection risk compared with those using low-concentration AGIs (IRR 0.918, 95% CI: 0.854-0.987). We noted a dose-response relationship in the effects of DM medications on TB risk. Accordingly, we suggest that DM patients use AGIs to benefit from their protective effect on TB infection risk.

A safety and tolerability profile comparison between dipeptidyl peptidase-4 inhibitors and sulfonylureas in diabetic patients: A systematic review and meta-analysis

BACKGROUND

The first treatment approach for type 2 diabetes mellitus is lifestyle change and metformin, but it is usually not sufficient. For some time, the anti-hyperglycemic classes of sulfonylureas and dipeptidyl peptidase-4 (DPP-4) inhibitors were considered second-line of treatment, since they show similar efficacy effect. However, the recent ADA-EASD consensus gives the preference to DPP-4 inhibitors compared to sulfonylureas, except if cost is a major problem. We performed a meta-analysis for safety and tolerability profile to comprehend which treatment has less adverse events.

METHODS

PUBMED and EMBASE databases were searched from inception until July 2017 to retrieve RCT studies comparing DPP-4 inhibitors and sulfonylureas treatments in adult type 2 diabetes patients. There was no language restriction. We extracted and combined data from studies comparison that reported safety profile and weight change. A random effect, meta-analytic model was applied to all calculations. Cochrane collaboration tool was used to assess quality and bias of the included studies. Trial registered with PROSPERO (CRD42017075823).

FINDINGS

Out of 1472 articles identified in our search and screened for eligibility, 36 studies comparing DPP-4 inhibitors and sulfonylureas were identified. DPP-4 inhibitors in combination with metformin had less overall adverse events (RR: 0·90; 95% CI, 0·86-0·94; p < 0·0001; I² = 83%; 17 studies), cardiovascular events (RR: 0·54; 95% CI, 0·37-0·79; p = 0·002; I² = 0%; 6 studies), hypoglycemia (RR: 0·17; 95% CI, 0·13-0·22; p < 0·00001; I² = 76%; 17 studies) and severe hypoglycemic events (RR: 0·10; 95% CI, 0·05-0·19; p < 0·00001; I² = 0%; 12 studies). The mean difference of the weight change was 1·92 kg in favor of DPP-4 inhibitors in combination with metformin in relation to sulfonylureas in combination with metformin. Monotherapy with DPP-4 inhibitors also had less rates of hypoglycemia (RR: 0·31; 95% CI, 0·24-0·41; p < 0·00001; I² = 0%; 8 studies) and severe hypoglycemic events (RR: 0·26; 95% CI, 0·10-0·66; p = 0·004; I² = 0%; 8 studies) and patients did not gain 1·19 kg.

INTERPRETATION

These results suggest better safety profile for DPP-4 inhibitors than sulfonylureas for both comparisons, and it is more notable when the treatment regimen includes metformin.

FUNDING

This study was funded by Takeda Pharmaceuticals, Brazil.

Chlorflavonin Targets Acetohydroxyacid Synthase Catalytic Subunit IlvB1 for Synergistic Killing of Mycobacterium tuberculosis

The flavonoid natural compound chlorflavonin was isolated from the endophytic fungus Mucor irregularis, which was obtained from the Cameroonian medicinal plant Moringa stenopetala. Chlorflavonin exhibited strong growth inhibitory activity in vitro against Mycobacterium tuberculosis (MIC₉₀ 1.56 μM) while exhibiting no cytotoxicity toward the human cell lines MRC-5 and THP-1 up to concentrations of 100 μM. Mapping of resistance-mediating mutations employing whole-genome sequencing, chemical supplementation assays, and molecular docking studies as well as enzymatic characterization revealed that chlorflavonin specifically inhibits the acetohydroxyacid synthase catalytic subunit IlvB1, causing combined auxotrophies to branched-chain amino acids and to pantothenic acid. While exhibiting a bacteriostatic effect in monotreatment, chlorflavonin displayed synergistic effects with the first-line antibiotic isoniazid and particularly with delamanid, leading to a complete sterilization in liquid culture in combination treatment. Using a fluorescent reporter strain, intracellular activity of chlorflavonin against Mycobacterium tuberculosis inside infected macrophages was demonstrated and was superior to streptomycin treatment.

Modulating antibiotic activity towards respiratory bacterial pathogens by co-medications: a multi-target approach

Non-antibiotic drugs can modulate bacterial physiology and/or antibiotic activity, opening perspectives for innovative therapeutic strategies. Focusing on respiratory pathogens and considering in vitro, in vivo, and clinical data, here we examine the effect of these drugs on the expression of resistance mechanisms, biofilm formation, and intracellular survival, as well as their influence on the activity of antibiotics on bacteria. Beyond the description of the effects observed, we also comment on concentrations that are active and discuss the mechanisms of drug-drug or drug-target interactions. This discussion should be helpful in defining useful targets for adjuvant therapy and establishing the corresponding pharmacophores for further drug fine-tuning.

Tuberculosis and nature's pharmacy of putative anti-tuberculosis agents

Due to the growing problem of drug resistant Mycobacterium tuberculosis strains, coupled with the twinning of tuberculosis (TB) to human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), the burden of TB is now difficult to manage. Therefore, new antimycobacterial agents are being sought from natural sources. This review focuses on natural antimycobacterial agents from endophytes and medicinal plants of Africa, Europe, Asia, South America and Canada. In the countries mentioned in this review, numerous plant species display putative anti-TB activity. Several antimycobacterial chemical compounds have also been isolated, including: ellagitannin punicalagin, allicin, anthraquinone glycosides, iridoids, phenylpropanoids, beta-sitosterol, galanthimine, crinine, friedelin, gallic acid, ellagic acids, anthocyanidin, taraxerol, termilignan B, arjunic acid, glucopyranosides, 1-epicatechol, leucopelargonidol, hydroxybenzoic acids, benzophenanthridine alkaloids, neolignans, and decarine. These compounds may provide leads to novel and more efficacious drugs to lessen the global burden of TB and drug-resistant M. tuberculosis strains. If there is a long-term remedy for TB, it must lie in nature's pharmacy of putative antimycobacterial agents.

Clinical outcomes of linezolid treatment for extensively drug-resistant tuberculosis in Beijing, China: a hospital-based retrospective study

Studies have shown that linezolid achieves good clinical outcomes against multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB). However, the efficacy of linezolid for individual TB patients and its precise contribution to combination regimens remain unclear for Chinese patients. This study examined the clinical outcomes and safety of linezolid in adults with XDR pulmonary TB at the Chinese PLA 309 hospital. Sixteen XDR-TB patients received linezolid (600 mg daily) in addition to vitamin B6 (50-100 mg daily) as part of their individualized treatment regimens. Of the 16 patients, 14 had received previous treatment for tuberculosis. Sputum samples for all patients showed high colony-forming unit counts when tested by a real-time polymerase chain reaction (PCR). In addition, a high proportion of patients had cavitary lesions in the lungs. Eleven of the 16 patients (68.75%) had successfully completed therapy with documented negative quantitative PCR (qPCR) data and cultures at follow-up (mean = 12 months). Three patients (18.75%) are still receiving treatment, and all 3 have shown clinical and radiographic improvement. Linezolid was discontinued for 2 patients with persistent positive qPCR data and cultures because they developed severe, intractable diarrhea and nausea shortly after beginning treatment. Data indicated that linezolid was a well-tolerated and efficient treatment for XDB-TB in of Chinese patients.