Quinoline Derivatives as Promising Scaffolds for Antitubercular Activity: A Comprehensive Review.

BACKGROUND: Heterocyclic compounds and their derivatives play a significant role in the design and development of novel quinoline drugs. Among the various pharmacologically active heterocyclic compounds, quinolines stand out as the most significant rings due to their broad pharmacological roles, specifically antitubercular activity, and their presence in plant-based compounds. Quinoline is also known as benzpyridine, benzopyridine, and 1-azanaphthalene. It has a benzene ring fused with a pyridine ring, and both rings share two carbon atoms. The importance of quinoline lies in its incorporation as a key component in various natural compounds found in medicinal plant families like Fumariaceae, Berberidaceae, Rutaceae, Papavaraceae, and others. OBJECTIVE: This article is expected to have a significant impact on the advancement of effective antitubercular drugs. Through harnessing the potent activity of quinoline derivatives, the research aims to make valuable contributions to combating tuberculosis more efficiently and ultimately reducing the global burden of this infectious disease. METHODS: Numerous nitrogen-containing heterocyclic compounds exhibit significant potential as antitubercular agents. These chemicals have fused aromatic nitrogen-heterocyclic nuclei that can change the number of electrons they have, which can change their chemical, physical, and biological properties. This versatility comes from their ability to bind with the receptors in multiple modes, a critical aspect of drug pharmacological screening. Among these compounds, quinoline stands out as it incorporates a stable fusion of a benzene ring with a pyridine nucleus. Quinolines have demonstrated a diverse range of pharmacological activities, including but not limited to anti-tubercular, anti-tumor, anticoagulant, anti-inflammatory, antioxidant, antiviral, antimalarial, anti-HIV, and antimicrobial effects. RESULTS: Some molecules, such as lone-paired nitrogen species, include pyrrole, pyrazole, and quinoline. These molecules contain nitrogen and take part in metabolic reactions with other molecules inside the cell. However, an excessive accumulation of reactive nitrogen species can lead to cytotoxicity, resulting in damage to essential biological macromolecules. Among these compounds, quinoline stands out as the oldest and most effective one, exhibiting a wide range of significant properties such as antitubercular, antimicrobial, anti-inflammatory, antioxidant, analgesic, and anticonvulsant activities. Notably, naturally occurring quinoline compounds, such as quinine, have proven to be potent antimalarial drugs. CONCLUSION: This review highlights quinoline derivatives' antitubercular potential, emphasizing recent research advancements. Utilizing IC50 values, the study emphasizes the efficacy of various quinoline substitutions, hybrids, and electron-withdrawing groups against MTB H37Rv. Continued research is essential for developing potent, low-toxicity quinoline derivatives to combat tuberculosis.

A descriptive study on isoniazid resistance-associated mutations, clustering and treatment outcomes of drug-resistant tuberculosis in a high burden country.

PURPOSE: To describe katG and inhA mutations, clinical characteristics, treatment outcomes and clustering of drug-resistant tuberculosis (TB) in the State of São Paulo, southeast Brazil. METHODS: Mycobacterium tuberculosis isolates from patients diagnosed with drug-resistant TB were screened for mutations in katG and inhA genes by line probe assay and Sanger sequencing, and typed by IS6110-restriction fragment-length polymorphism for clustering assessment. Clinical, epidemiological and demographic data were obtained from surveillance information systems for TB. RESULTS: Among the 298 isolates studied, 127 (42.6%) were isoniazid-monoresistant, 36 (12.1%) polydrug-resistant, 93 (31.2%) MDR, 16 (5.4%) pre-extensively drug-resistant (pre-XDR), 9 (3%) extensively drug-resistant (XDR) and 17 (5.7%) susceptible after isoniazid retesting. The frequency of katG 315 mutations alone was higher in MDR isolates, while inhA promoter mutations alone were more common in isoniazid-monoresistant isolates. Twenty-six isolates phenotypically resistant to isoniazid had no mutations either in katG or inhA genes. The isolates with inhA mutations were found more frequently in clusters (75%) when compared to the isolates with katG 315 mutations (59.8%, p = 0.04). In our population, being 35-64 years old, presenting MDR-, pre-XDR- or XDR-TB and being a retreatment case were associated with unfavourable TB treatment outcomes. CONCLUSION: We found that katG and inhA mutations were not equally distributed between isoniazid-monoresistant and MDR isolates. In our population, clustering was higher for isolates with inhA mutations. Finally, unfavourable TB outcomes were associated with specific factors.

Hepatoprotective effect of hydromethanol extract of Otostegia integrifolia benth leaves in isoniazid and rifampicin induced Swiss albino mice.

Introduction: Drug-induced liver injury is the most common cause of acute liver failure. Off-Target effect "hepatotoxicity "frequently detected during clinical examination of patients on anti-Tb medication particularly isoniazid (INH), and rifampin (RMP). However, there is no any treatment option against isoniazid and rifampicin induced hepatotoxicity. It is, therefore, necessary to search for effective affordable and safe drugs from medicinal plants for the prevention of liver toxicity caused by isoniazid and rifampicin. The aim the current study is to evaluate hepatoprotective effect of hydro methanol extract from Otostegia integrifolia leaves in isoniazid and rifampicin-induced hepatotoxicity in Swiss albino mice. Methods: O. integrifolia leaves powder was macerated in hydromethanol and thirty Swiss albino mice 29.0-40.6 g were grouped in to five groups. Group I were given 20 ml/kg distilled water, group II were given 100 mg INH and 150 mg RIF per kg body weight. Group III, group IV, and group V were given 200 mg extract, 400 mg extract, and 100 mg of N-acetyl cysteine respectively per kg 1hr before induction with 100 mg INH plus 150 mg RIF per kg. The treatments were followed for 14 days. On the 15th day, all mice were anaesthetized with diethyl ether; blood samples were collected for the assessment liver enzyme and function test. Results: Group II mice's serum ALT, AST and total bilirubin levels were significantly increased and serum total protein and albumin levels were significantly decreased as compared with group I mice. The groups of mice treated with O. integrifolia at a dose of 400 mg/kg and N-acetyl cysteine AST, ALT and total bilirubin level were significantly decreased; and total protein and albumin levels were significantly (P < 0.05) increased as compared with group II. The liver index of the group IV showed decreased (P < 0.05) as compared to the group II. Conclusion: Evidence from our study revealed that the hydromethanol extract of O. integrifolia has a hepatoprotective effect against isoniazid and rifampicin-induced hepatotoxicity in Swiss Albino mice. This protective effect of O. integrifolia extract may be based on its metal ion reducing power, free radical scavenging activity, and anti-inflammatory activity and could be used as a potential therapeutic option.

[Treatment of tuberculosis: what is new?] / Therapie der Tuberkulose: Was gibt es Neues?

Never before have so many people around the world been simultaneously affected by tuberculosis. Tuberculosis is the leading cause of death from a bacterial infectious disease worldwide. The World Health Organization's ambitious goal from 2014 of achieving global elimination of tuberculosis does not seem realistic, but on current trends, tuberculosis could be eliminated in the European Union by 2040. Since the beginning of 2022, there have been more innovations for the treatment of tuberculosis than in no other comparable time period before. One month of rifapentine and isoniazid is effective in treating latent tuberculosis infection. However, rifapentine is licensed in the USA but not in the EU and must be imported for individual cases. The duration of the standard treatment for tuberculosis can be shortened to four months but this treatment regimen is also based on rifapentine, in addition to isoniazid, pyrazinamide, and moxifloxacin. The approval of rifapentine in Europe is a much-needed step towards shortening the treatment of tuberculosis. With new drugs an even shorter standard treatment of only 2 months is possible. The treatment of multidrug-resistant/rifampicin-resistant tuberculosis (MDR-/RR-TB) has been shortened to six months, the same length as the standard treatment available in Germany. The combination of bedaquiline, pretomanid, linezolid ± moxifloxacin, cured around 90% of affected patients were cured in studies with a treatment duration of six months. With 19 drugs in clinical trials, the treatment of tuberculosis is expected to continue to improve rapidly in the coming years.

Isoniazid-N-acylhydrazones as promising compounds for the anti-tuberculosis treatment.

Tuberculosis (TB), a disease caused by Mycobacterium tuberculosis complex, still presents significant numbers of incidence and mortality, in addition to several cases of drug resistance. Resistance, especially to isoniazid, which is one of the main drugs used in the treatment, has increased. In this context, N-acylhydrazones derived from isoniazid have shown important anti-Mycobacterium tuberculosis activity. Hence, this work aimed to determine the anti-TB potential of 11 isoniazid-N-acylhydrazones (INH-acylhydrazones). For this purpose, the determination of minimum inhibitory concentration (MIC) against M. tuberculosis H37Rv and clinical isolates was carried out. Drug combination, minimum bactericidal concentration, cytotoxicity, and in silico parameters were also performed. INH-acylhydrazones (2), (8), and (9) had MIC for M. tuberculosis H37Rv similar to or lower than isoniazid, and bactericidal activity was observed. In addition, these compounds showed low cytotoxicity, with a selectivity index greater than 3,000. Interesting results were also obtained in the drug combination assay, with synergistic combinations with isoniazid, ethambutol, and rifampicin. In the in silico study, INH-acylhydrazones behaved similarly to INH, but with improvements in some aspects. Based on these findings, it is concluded that compounds (2), (8), and (9) are considered promising scaffolds and warrant further investigation for designing future antimicrobial drugs.

A novel perspective on the preventive treatment of hydrazine compound-induced liver injury: Isoniazid liver injury as an example.

ETHNOPHARMACOLOGICAL RELEVANCE: Anethum graveolens L. (dill), which has been used as a medicine, spice and aromatic plant since ancient times, is not only a traditional Chinese medicines but also an important medicinal and functional food in Europe and Central and South Asia. In ethnomedicine, dill reportedly exerts a protective effect on the liver and has been widely used as a traditional medicine for the treatment of jaundice in the liver and spleen and inflammatory gout diseases in Saudi Arabia. Furthermore, studies have found that dill can regulate the NAT2 enzyme, and this plant was thus selected to study its alleviating effect on isoniazid liver injury. AIM OF THE STUDY: The purpose of this study was to explore the effect of dill on alleviating liver injury induced by hydrazine compounds represented by isoniazid through the use of network pharmacology combined with in vivo and in vitro experimental verifications. MATERIALS AND METHODS: First, we screened the key targets of dill in the treatment of liver injury through the use of network pharmacology; we then performed GO and KEGG pathway enrichment analyses using the DAVID database. We also verified the alleviative and anti-inflammatory effects of dill on isoniazid liver injury in rats by animal experiments. We further investigated the modulating effect of dill on the enzymatic activity of NAT2, a common metabolizing enzyme of hydrazine compounds. RESULTS: A total of 111 key targets were screened through network pharmacology. In vivo experiments showed that dill reduced the amount of inflammatory factors produced by isoniazid, such as IL-10, IL-1ß, TNF-α and IL-6, restored the levels of ALT, AST, r-GT, AKP and TBA in vivo, and attenuated isoniazid liver injury. Both in vivo and vitro results indicated that dill could regulate the expression of NAT2 enzymes. CONCLUSIONS: The results tentatively demonstrate that dill can alleviate isoniazid liver injury through multiple components, targets and pathways and exerts a regulatory effect on the NAT2 enzyme, and these findings thus provide new ideas for subsequent studies on hydrazide liver injury--reducing the risk of hydrazide-induced liver injury through anti-inflammation and regulation of NAT2 enzymes.

Folic acid protects against tuberculosis-drug-induced liver injury in rats and its potential mechanism by metabolomics.

Observational study indicated that folic acid (FA) supplementation may protect against tuberculosis-drug-induced liver injury (TBLI). The aim is to investigate the effect and mechanism of FA on TBLI in rats. Liver injury was induced by a daily gavage of isoniazid (INH) and rifampicin (RIF) in the model and FA groups. Rats in the FA group were also treated with 2.5 mg/kg body weight FA. Rats in the control group were not treated. Eight rats were used in each group. The severity of liver injury was measured by the serum levels of hepatic enzymes and histological score. The metabolites in serum and liver tissues were analyzed by HPLC-Q-TOF-MS/MS. FA treatment significantly reduced alanine aminotransferase and liver necrosis. Seventy-nine differential metabolites in the serum and liver tissues were identified among the three groups. N-acylethanolamines, INH and RIF metabolites, phosphatidylcholines, lysophosphatidylcholines, monoglycerides, diglycerides and bile acids were regulated by FA treatment, involving key metabolic pathways, such as N-acylethanolamine metabolism, INH and RIF metabolism, liver regeneration, inflammation alleviation and bile acid metabolism. RT-PCR and western blotting results confirmed the altered N-acylethanolamine metabolism and improved drug metabolism by FA. In conclusion, FA was protective against TBLI, which may be related to the regulation of N-acylethanolamine metabolism and drug detoxification by FA.

Protective Effect of Hedyotis diffusa Willd. Ethanol Extract on Isoniazid-Induced Liver Injury in the Zebrafish Model.

Objective: This study aims to investigate the hepatoprotective effect and molecular mechanism of Hedyotis diffusa Willd. ethanol extract (HDWE) against isoniazid (INH)-induced liver injury in the zebrafish model. Methods: INH-induced liver injury model was established by adding an immersion bath of INH in 3 days post-fertilisation (dpf) healthy transgenic zebrafish with liver-specific fluorescence (L-FABP: EGFP). HDWE and INH were given to the zebrafish to observe liver morphology and pathology, fluorescence intensity, and the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and superoxide dismutase (SOD), as well as the content of glutathione (GSH). The chemical composition of HDWE was analysed using high-performance liquid chromatography coupled with a quadrupole-time-of flight hybrid mass spectrometer (HPLC-Q-TOF-MS). The bioactive compounds, molecular targets and signalling pathways of HDWE were predicted using network pharmacology. Subsequently, molecular docking was adopted to analyze the affinities between the bioactive components and targets by Autodock. Finally, in vitro experiments were conducted to further verify the findings. Results: Our findings showed that HDWE had a remarkable protective effect on INH-induced liver injury in zebrafish. Twenty compounds in HDWE were identified. Nineteen hub targets were identified as possible targets of HDWE, and a compound-target-pathway network was constructed. Nine bioactive compounds, ten molecular targets, and seven key signalling pathways were found to play a pivotal role in the hepatoprotective effect of HDWE against INH-induced liver injury. In vitro studies revealed that the important bioactive compound quercetin-3-O-sambubioside (QSA) could significantly reverse INH-induced cell viability decreases and had a significant effect on the associated targets predicted by network pharmacology and molecular docking. Conclusion: In this study, through the research of hepatoprotective effect of HDWE and bioinformatics analysis, the bioactive compounds, important pathways and key molecular targets were discovered. These findings could provide scientific evidence for the use of HDW in liver injury and prove to help explore its efficacy and the mechanism of action.

Mechanistic insights into the antimycobacterial action of unani formulation, Qurs Sartan Kafoori.

Background and aim: Tuberculosis (TBC) is a deadly disease and major health issue in the world. Emergence of drug resistant strains further worsens the efficiency of available anti-TBC drugs. Natural compounds and particularly traditional medicines such as Unani drugs are one of the promising alternatives that have been widely used nowadays. This study aims to evaluate the efficacy of unani drug Qurs-e-Sartan Kafoori (QSK) on Mycobacterium tuberculosis (MTB). Experimental procedures: Drug susceptibilities were estimated by broth microdilution assay. Cell surface integrity was assessed by ZN staining, colony morphology and nitrocefin hydrolysis. Biofilms were visualized by crystal violet staining and measurement of metabolic activity and biomass. Lipidomics analysis was performed using mass spectrometry. Host pathogen interaction studies were accomplished using THP-1 cell lines to estimate cytokines by ELISA kit, apoptosis and ROS by flow cytometry. Results: QSK enhanced the susceptibilities of isoniazid and rifampicin and impaired membrane homeostasis as depicted by altered cell surface properties and enhanced membrane permeability. In addition, virulence factor, biofilm formation was considerably reduced in presence of QSK. Lipidomic analysis revealed extensive lipid remodeling. Furthermore, we used a THP-1 cell line model, and investigated the immunomodulatory effect by estimating cytokine profile and found change in expressions of TNF-α, IL-6 and IL-10. Additionally, we uncover reduced THP-1 apoptosis and enhanced ROS production in presence of QSK. Conclusion: Together, this study validates the potential of unani formulation (QSK) with its mechanism of action and attempts to highlight its significance in MDR reversal.

Molecular detection of isoniazid monoresistance improves tuberculosis treatment: A retrospective cohort in France.

OBJECTIVES: Isoniazid-monoresistant tuberculosis (HR-TB) requires early diagnosis and adapted treatment to achieve optimal outcomes. The primary aim of the study was to assess the impact of the implementation of rapid diagnostic tests on HR-TB treatment in France. METHODS: We designed a retrospective multicentre study including consecutive HR-TB patients diagnosed in 2016 and 2017. Implementation of a molecular assay detecting isoniazid resistance directly on a clinical sample was recorded. The association between early implementation of such assays and adequate treatment was assessed by a multivariable Cox proportional hazards model. RESULTS: Overall, 99 HR-TB patients were included from 20 University Hospitals. Among all smear-positive HR-TB patients, only 26% beneficiated from early molecular HR detection. This detection was independently associated with shorter time to adequate treatment (HR = 2.0 [1.1-3.8], p = 0.03). CONCLUSION: In our study, molecular detection of HR on an initial sample was independently associated with earlier treatment adaptation.

Evaluating the clinical impact of routine whole genome sequencing in tuberculosis treatment decisions and the issue of isoniazid mono-resistance.

BACKGROUND: The UK has implemented routine use of whole genome sequencing (WGS) in TB diagnostics. The WHO recommends addition of a fluoroquinolone for isoniazid mono-resistance, so early detection may be of use. The aim of this study was to describe the clinical utility and impact of WGS on treatment decisions for TB in a low incidence high resource clinical setting. The clinical turnaround time (TAT) for WGS was analysed in comparison to TB PCR using Xpert MTB/RIF (Cepheid, Sunnyvale, CA) results where available and subsequent phenotypic drug susceptibility testing (DST) when required. METHODS: This was a retrospective analysis of TB cases from January 2018 to March 2019 in London. Susceptibility and TAT by WGS, phenotypic DST, TB PCR using Xpert MTB/RIF were correlated to drug changes in order to describe the utility of WGS on treatment decisions on isoniazid mono-resistance in a low incidence high resource setting. RESULTS: 189 TB cases were identified; median age 44 years (IQR 28-60), m:f ratio 112:77, 7 with HIV and 6 with previous TB. 80/189 cases had a positive culture and WGS result. 50/80 were fully sensitive to 1st line treatment on WGS, and the rest required additional DST. 20/80 cases required drug changes; 12 were defined by WGS: 8 cases had isoniazid mono-resistance, 2 had MDR-TB, 1 had isoniazid and pyrazinamide resistance and 1 had ethambutol resistance. The median TAT for positive culture was 16 days (IQR 12.5-20.5); for WGS was 35 days (IQR 29.5-38.75) and for subsequent DST was 86 days (IQR 69.5-96.75), resulting in non-WHO regimens for a median of 50.5 days (IQR 28.0-65.0). 9/12 has TB PCRs (Xpert MTB/RIF), with a median TAT of 1 day. CONCLUSION: WGS clearly has a substantial role in our routine UK clinical settings with faster turnaround times in comparison to phenotypic DST. However, the majority of treatment changes defined by WGS were related to isoniazid resistance and given the 1 month TAT for WGS, it would be preferable to identify isoniazid resistance more quickly. Therefore if resources allow, diagnostic pathways should be optimised by parallel use of WGS and new molecular tests to rapidly identify isoniazid resistance in addition to rifampicin resistance and to minimise delays in starting WHO isoniazid resistance treatment.

Pyridoxine in isoniazid-induced psychosis.

Isoniazid is a first-line drug for the management of tuberculosis. Recent changes in paediatric tuberculosis guidelines have insisted on a higher daily dose of isoniazid. Given the burden of paediatric tuberculosis in developing countries, it is pertinent that paediatricians are well versed with all possible adverse effects associated with isoniazid therapy and not just common ones like hepatotoxicity or peripheral neuropathy. Psychosis is one such rare adverse effect which has a reported incidence of 1%-2%. Here, we report a case of isoniazid-induced psychosis in a 4-year-old girl. The purpose of this report is to sensitise the paediatric healthcare community regarding this rare clinical entity along with highlighting the putative role of pyridoxine supplementation in the management of isoniazid-induced psychosis.

Effect of niacin supplementation on nausea-like behaviour in an isoniazid-induced mouse model of pellagra.

Niacin deficiency causes pellagra, the symptoms of which include dermatitis, diarrhoea and dementia. Investigating the mechanism underlying these phenotypes has been challenging due to the lack of an appropriate animal model. Here, we report a mouse model of pellagra-related nausea induced by feeding mice a low-niacin diet and administering isoniazid (INH), which is thought to induce pellagra. Mice fed a normal or low-niacin diet received INH (0·3 or 1·0 mg/mg per animal, twice daily, 5 d), and nausea was evaluated based on pica behaviour, which considered the rodent equivalent of the emetic reflex. Furthermore, the effect of therapeutic niacin administration on nausea was evaluated in this model. Urinary and hepatic metabolite levels were analysed by LC coupled with MS. INH-induced pica was observed in mice fed a low-niacin diet but not in those fed a normal diet. Levels of urinary metabolites, such as 1-methyl-2-pyridone-5-carboxamide, kynurenic acid and xanthurenic acid, were significantly reduced in the mice treated with INH compared with those that did not receive INH. Furthermore, niacin supplementation prevented pica and restored the levels of some metabolites in this mouse model. Our findings suggest that INH-related nausea is pellagra-like. We also believe that our newly established method for quantifying pica is a useful tool for investigating the mechanisms of pellagra-related nausea.

The Indian Network of Drug-Induced Liver Injury: Etiology, Clinical Features, Outcome and Prognostic Markers in 1288 Patients.

BACKGROUND: Etiology of and outcomes following idiosyncratic drug-induced liver injury (DILI) vary geographically. We conducted a prospective study of DILI in India, from 2013 to 2018 and summarize the causes, clinical features, outcomes and predictors of mortality. METHODS: We enrolled patients with DILI using international DILI expert working group criteria and Roussel Uclaf causality assessment method. Follow-up was up to 3 months from onset of DILI or until death. Multivariate logistics regression was carried out to determine predictors of non-survival. RESULTS: Among 1288 patients with idiosyncratic DILI, 51.4% were male, 68% developed jaundice, 68% required hospitalization and 8.2% had co-existing HIV infection. Concomitant features of skin reaction, ascites, and encephalopathy (HE) were seen in 19.5%, 16.4%, and 10% respectively. 32.4% had severe disease. Mean MELD score at presentation was 18.8 ± 8.8. Overall mortality was 12.3%; 65% in those with HE, 17.6% in patients who fulfilled Hy's law, and 16.6% in those that developed jaundice. Combination anti-TB drugs (ATD) 46.4%, complementary and alternative medicines (CAM) 13.9%, anti-epileptic drugs (AED) 8.1%, non-ATD antimicrobials 6.5%, anti-metabolites 3.8%, anti-retroviral drugs (ART)3.5%, NSAID2.6%, hormones 2.5%, and statins 1.4% were the top 9 causes. Univariate analysis identified, ascites, HE, serum albumin, bilirubin, creatinine, INR, MELD score (p < 0.001), transaminases (p < 0.04), and anti-TB drugs (p = 0.02) as predictors of non-survival. Only serum creatinine (p = 0.017), INR (p < 0.001), HE (p < 0.001), and ascites (p = 0.008), were significantly associated with mortality on multivariate analysis. ROC yielded a C-statistic of 0.811 for MELD and 0.892 for combination of serum creatinine, INR, ascites and HE. More than 50 different agents were associated with DILI. Mortality varied by drug class: 15% with ATD, 13.6% with CAM, 15.5% with AED, 5.8% with antibiotics. CONCLUSION: In India, ATD, CAM, AED, anti-metabolites and ART account for the majority of cases of DILI. The 3-month mortality was approximately 12%. Hy's law, presence of jaundice or MELD were predictors of mortality.

Superfast Synthesis of Stabilized Silver Nanoparticles Using Aqueous Allium sativum (Garlic) Extract and Isoniazid Hydrazide Conjugates: Molecular Docking and In-Vitro Characterizations.

Green synthesis of silver nanoparticles (AgNPs) was synthesized from fresh garlic extract coupled with isoniazid hydrazide (INH), a commonly used antibiotic to treat tuberculosis. A molecular docking study conducted with the selected compounds compared with anthranilate phosphoribosyltransferase (trpD) from Mycobacterium tuberculosis. The aqueous extract of garlic was prepared and mixed with silver nitrate (AgNO3) solution for the superfast synthesis of stable AgNPs. INH was then conjugated with AgNPs at different ratios (v/v) to obtain stable INH-AgNPs conjugates (AgNCs). The resulting AgNCs characterized by FTIR spectra revealed the ultrafast formation of AgNPs (<5 s) and perfectly conjugated with INH. The shifting of λmax to longer wavelength, as found from UV spectral analysis, confirmed the formation of AgNCs, among which ideal formulations (F7, F10, and F13) have been pre-selected. The zeta particle size (PS) and the zeta potential (ZP) of AgNPs were found to be 145.3 ± 2.1 nm and -33.1 mV, respectively. These data were significantly different compared to that of AgNCs (160 ± 2.7 nm and -14.4 mV for F7; 208.9 ± 2.9 nm and -19.8 mV for F10; and 281.3 ± 3.6 nm and -19.5 mV for F13), most probably due to INH conjugation. The results of XRD, SEM and EDX confirmed the formation of AgNCs. From UV spectral analysis, EE of INH as 51.6 ± 5.21, 53.6 ± 6.88, and 70.01 ± 7.11 %, for F7, F10, and F13, respectively. The stability of the three formulations was confirmed in various physiological conditions. Drug was released in a sustainable fashion. Besides, from the preferred 23 compounds, five compounds namely Sativoside R2, Degalactotigonin, Proto-desgalactotigonin, Eruboside B and Sativoside R1 showed a better docking score than trpD, and therefore may help in promoting anti-tubercular activity.

The protective effect of lycopene against oxidative kidney damage associated with combined use of isoniazid and rifampicin in rats

It is known that the combined use of antibiotics, such as isoniazid and rifampicin, in the treatment of tuberculosis causes oxidative kidney damage. The aim of this study was to biochemically and histopathologically investigate the effect of lycopene on oxidative kidney damage due to the administration of isoniazid and rifampicin in albino Wistar male rats. Lycopene at a dose of 5 mg/kg was orally administered to lycopene+isoniazid+rifampicin (LIR) rats, and normal sunflower oil (0.5 mL) was orally administered to isoniazid+rifampicin (IR) and healthy control (HG) rats as vehicle by gavage. One hour after the administration of lycopene and vehicle, 50 mg/kg isoniazid and rifampicin were given orally to the LIR and IR groups. This procedure was performed once a day for 28 days. Rats were sacrificed by a high dose of anesthesia at the end of this period, and oxidant-antioxidant parameters were measured in the removed kidney tissues. Creatinine and blood urea nitrogen (BUN) levels were measured in blood samples, and kidney tissues were also evaluated histopathologically. The combined administration of isoniazid and rifampicin changed the oxidant-antioxidant balance in favor of oxidants, and it increased blood urea nitrogen and creatinine levels, which are indicators of kidney function. Co-administration of isoniazid and rifampicin also caused oxidative kidney damage. Lycopene biochemically and histopathologically decreased oxidative kidney damage induced by isoniazid and rifampicin administration. These results suggested that lycopene may be beneficial in the treatment of nephrotoxicity due to isoniazid and rifampicin administration.

Isoniazid: A rare drug-induced cause for bilateral dentate nuclei hyperintensity.

Dentate nucleus, the largest deep nucleus of the cerebellum, is affected by numerous conditions, including leukodystrophies, toxins, drugs, infections, and various metabolic and inflammatory conditions. This case report is a drug-induced cerebellitis, caused by isoniazid (INH), characterized in magnetic resonance imaging (MRI) as bilateral dentate nuclei hyperintensity. Isoniazid, an antituberculosis therapy (ATT) drug, is both neurotoxic and hepatotoxic but cerebellitis is a rare complication. INH-induced cerebellitis is characterized in MRI by bilateral and symmetrical T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity in dentate nuclei. Though metronidazole is the most common drug associated with such MRI signal changes in the dentate nucleus, the uncommon association with INH has been described in literature especially in patients with renal function impairment. MRI findings together with clinical signs of cerebellar involvement, in a patient with abnormal renal function tests and in whom the ATT regimen was recently initiated, favors the diagnosis of INH toxicity. INH withdrawal and pyridoxine supplementation can reverse this condition.

Initial resistance to companion drugs should not be considered an exclusion criterion for the shorter multidrug-resistant tuberculosis treatment regimen.

OBJECTIVES: We investigated whether companion drug resistance was associated with adverse outcomes of the shorter multidrug-resistant tuberculosis (MDR-TB) treatment regimen in Bangladesh after adjustment for fluoroquinolone resistance. METHODS: MDR-TB/rifampicin-resistant tuberculosis patients registered for treatment with a standardized gatifloxacin-based shorter MDR-TB treatment regimen were selected for the study. Drug resistance was determined by the proportion method, gatifloxacin and isoniazid minimum inhibitory concentration testing for selected isolates, and whole-genome sequencing. RESULTS: Low-level fluoroquinolone resistance and high-level fluoroquinolone resistance were the most important predictors of adverse outcomes, with pyrazinamide resistance having a significant yet lower impact. In patients with fluoroquinolone-/second-line-injectable-susceptible tuberculosis, non-eligibility for the shorter MDR-TB treatment regimen (initial resistance to pyrazinamide, ethionamide, or ethambutol) was not associated with adverse outcome (adjusted odds ratio 1.01; 95% confidence interval 0.4-2.8). Kanamycin resistance was uncommon (1.3%). Increasing levels of resistance to isoniazid predicted treatment failure, also in a subgroup of patients with high-level fluoroquinolone-resistant tuberculosis. CONCLUSIONS: Our results suggest that resistance to companion drugs in the shorter MDR-TB treatment regimen, except kanamycin resistance, is of no clinical importance as long as fluoroquinolone susceptibility is preserved. Hence, contrary to current WHO guidelines, exclusions to the standard regimen are justified only in the case of fluoroquinolone resistance. and possibly kanamycin resistance.

A retrospective cohort study of isoniazid-resistant tuberculosis treatment outcomes and isoniazid resistance-associated mutations in eastern China from 2013 to 2018.

OBJECTIVES: The current situation of isoniazid-resistant, rifampicin-susceptible tuberculosis (Hr-TB) and associated genetic factors is not clear in China. METHODS: A retrospective cohort study was conducted from 2013 to 2018 in Jiangsu Province, China. Phenotypic Hr-TB were identified by drug susceptibility testing on Lowenstein-Jensen medium and using a Mycobacterium Growth Indicator Tube 960 (MGIT 960) system, and mutations in the katG 315 codon and inhA promoter nucleotides -8, -15 and -16 were determined by GenoType MTBDRplus and sequencing. All of the Hr-TB patients enrolled were followed up until June 2019. RESULTS: A total of 1416 smear-positive sputum samples were collected, of which 57 were excluded due to the presence of nontuberculous mycobacteria. Finally, 63/1359 (4.6%) were determined as Hr-TB. After follow-up, 11 Hr-TB patients (17.5%) showed an unfavourable outcome, of whom 5 (7.9%) relapsed, 4 (6.3%) had treatment failure and 2 (3.2%) died. A total of 52 isolates (82.5%) were detected with either katG 315 or inhA promoter nucleotide -8, -15 or -16 mutations, whereas no canonical mutations were found in 8 isolates (12.7%); 3 isolates failed in mutation detection. TB history was found to be associated with unfavourable outcomes for Hr-TB (odds ratio = 6.13, 95% confidence interval 1.05-35.82; P = 0.04). However, mutations in katG 315 and the inhA promoter region were not found to be associated with Hr-TB unfavourable outcomes (P = 0.15). CONCLUSION: Unfavourable outcomes for Hr-TB are serious in eastern China, especially for previously treated patients. Meanwhile, current genetic determination of Hr-TB is inadequate.

Factors affecting uptake and completion of isoniazid preventive therapy among HIV-infected children at a national referral hospital, Kenya: a mixed quantitative and qualitative study.

BACKGROUND: Tuberculosis (TB) is the most common opportunistic infection and the leading cause of death in people living with HIV (PLHIV). HIV-infected children are at a higher risk of TB infection and disease compared to those without HIV. Isoniazid preventive therapy (IPT) is an effective intervention in preventing progression of latent TB infection to active TB. The World Health Organization (WHO) currently recommends that all children aged > 12 months and adults living with HIV in whom active TB has been excluded should receive a 6-months course of IPT as part of a comprehensive package of HIV care. Despite this recommendation, the uptake of IPT among PLHIV has been suboptimal globally. This study sought to determine the factors affecting IPT uptake and completion among HIV-infected children in a large HIV care centre in Nairobi, Kenya. METHOD: This was a cross-sectional mixed methods study comprising of quantitative and qualitative study designs. Medical records of 225 HIV-infected children aged 1 to < 10 years, in care in the Kenyatta National Hospital Comprehensive Care Centre (KNH CCC) were retrospectively reviewed, and 8 purposively selected healthcare providers and 18 consecutively selected caregivers of children were interviewed. RESULTS: IPT uptake among CLHIV in care in the KNH CCC was 68% (152/225) while the treatment completion rate was 82% (94/115). IPT-related health education and counselling were the main facilitators of IPT uptake and completion, while fear of adverse drug reaction, pill burden and lack of an integrated monitoring and evaluation system for IPT were the major barriers. CONCLUSION: The IPT uptake in this study was low and fell short of the set global target of > 90%. The completion rate was however acceptable. There is an urgent need to address the identified barriers.