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.

Rhus chinensis Mill. fruits alleviate liver injury induced by isoniazid and rifampicin through regulating oxidative stress, apoptosis, and bile acid transport.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhus chinensis Mill. is a species of the genus Rhus belonging to the family Anacardiaceae. Its fruits used to treat/prevent liver related diseases (e.g., jaundice and hepatitis) in folk medicine. Otherwise, the effects and underlying mechanisms of the fruits on the prevention of isoniazid and rifampicin-caused liver injury have not been investigated. AIM OF THE STUDY: To study the preventive effects and mechanisms of the Rhus chinensis Mill. fruits on isoniazid and rifampicin-caused liver injury. MATERIALS AND METHODS: This experiment was based on rifampicin (75 mg/kg/day) and isoniazid (75 mg/kg/day)-induced liver damage model to explain the pharmacological effects of Rhus chinensis Mill. fruits. The prevention of the extract from Rhus chinensis Mill. fruits on isoniazid and rifampicin-caused liver injury were evaluated using biochemical parameters, histopathological analysis, and immunofluorescence technique. Apart from that, the potential molecular mechanisms were elucidated by analyzing the expression of such crucial proteins participated in oxidative stress, apoptosis, and bile acid transport. RESULTS: The extract from Rhus chinensis Mill. fruits significantly reduced the levels of ALT, AST, TBIL, ALP and MDA. Besides, the extract, especially 800 mg/kg b.w., was remarkably decreased the content of TNF-α,IL-6 and IL-1ß, restored the levels of GSH and SOD. The results of Western blot also presented that the extract could activate the Nrf2 protein pathway and inhibit the expression of CYP2E1 to reduce oxidative stress. Meanwhile, the extract significantly up-regulated the expressions of BSEP and Mrp2 to regulate the transport of bile acid, and alleviated the cellular apoptosis via adjusting the expression of Bax and Bcl-2 proteins. CONCLUSIONS: Rhus chinensis Mill. fruits can prevent the liver injury induced by isoniazid and rifampicin in mice through adjusting the expressions of multiple proteins in oxidative stress, apoptosis, and bile acid transport pathways. This paper may provide scientific basis for the fruits as a Chinese medicine to prevent/cure liver injury.

Effects of Solanum lycopersicum L. (tomato) against isoniazid and rifampicin induced hepatotoxicity in wistar albino rats.

Anti-tuberculosis drugs are reported to cause hepatotoxicity, which varies from asymptomatic rise of the hepatic enzymes. Hepatoprotective plants plays important role to protect liver. This study investigated the hepatoprotective potential of the Solanum lycopersicum in rats intoxicated with Isoniazid and Rifampicin (INH+RIF) to induce hepatotoxicity. Thirty wistar albino rats were divided into five groups of six animals each. Group 1 rats were kept control while groups II, III, IV and V were administered with INH+RIF (75+150 mg/kg) orally, for seven consecutive days. For treatment, rats in group III received silymarin while animals in group IV and V were provided with 40 mg/kg and 80 mg/kg of Solanum lycopersicum extract, respectively. On day 0 and 8th blood samples were collected for the analysis of hepatic biomarkers. The data were subjected to one-way ANOVA and Bonferroni's post hoc test for statistical analysis. Hepatotoxicity induced by INH+RIF resulted in significant elevation of serum hepatic enzymes including Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Alkaline phosphatase (ALP), and total bilirubin while decreased the albumin level. The Solanum lycopersicum at dose of 80 mg/kg significantly reduced the hepatic enzymes AST, ALT, ALP and bilirubin while the albumin level was significantly increased. The treatment had non-significant effect on body and liver weight. Drug induced hepatotoxicity can be effectively treated with Solanum lycopersicum at 80 mg/kg dose.

Evidence of drug-induced hepatotoxicity in the Maghrebian population.

Drug-induced hepatotoxicity is one of the most challenging hepatic diseases faced nowadays due to a large number of drugs currently used in clinical practice, the enormous dietary supplements which are potentially hepatotoxic, as well as the ability to appear with different clinical symptoms and the absence of specific markers. The current research survey was conducted to investigate drug-induced hepatotoxicity and demographic characteristics of patients with liver damage in the general Maghrebian population between 1992 and 2018. To achieve this goal a questionnaire was adopted to report details on the undesirable effects of drugs and demographic characteristics of affected patients. The results obtained in the current survey showed that 1001 in 25 093 cases of drug-induced toxicity were registered with drug-induced liver damage between 1992 and 2018. Regarding demographic characteristics of affected patients, the most affected age group was 18 to 44-years-old with a percentage of 45.70% followed by the age group 45 to 64-year-old with a percentage of 27.20%. Females were the most frequently affected by the hepatic side effects of drugs vs. males. Paracetamol, isoniazid, rifampicin, and pyrazinamide were the main responsible drugs for liver damage in the study population. Alteration of biological parameters and subclinical phenomena were used as clinical manifestations of liver damage in the study population. The outcome of the present study suggests paying more attention to drugs used for medication and the involvement of rigorous clinical monitoring to prevent or to minimize the side effects of drugs.

The Anticonvulsant Effect of Hydroethanolic Leaf Extract of Calotropis procera (Ait) R. Br. (Apocynaceae).

A number of currently used drugs have been obtained from medicinal plants which are a major source of drugs. These drugs are either used in their pure form or modified to a semisynthetic drug. Drug discovery through natural product research has been fruitful over the years. Traditionally, Calotropis procera is used extensively in the management of epilepsy. This study is conducted to explore the anticonvulsant effect of a hydroethanolic leaf extract of Calotropis procera (CPE) in murine models. This effect was evaluated using picrotoxin-induced convulsions, strychnine-induced convulsions, and isoniazid- and pilocarpine-induced status epilepticus in mice of both sexes. The results showed that CPE (100-300 mg/kg) exhibited an anticonvulsant effect against strychnine-induced clonic seizures by significantly reducing the duration (p = 0.0068) and frequency (p = 0.0016) of convulsions. The extract (100-300 mg/kg) caused a profound dose-dependent delay in the onset of clonic convulsions induced by picrotoxin (p < 0.0001) and tonic convulsions (p < 0.0001) in mice. The duration of convulsions was reduced significantly also for both clonic and tonic (p < 0.0001) seizures as well. CPE (100-300 mg/kg), showed a profound anticonvulsant effect and reduced mortality in the pilocarpine-induced convulsions. ED50 (~0.1007) determined demonstrated that the extract was less potent than diazepam in reducing the duration and onset of convulsions but had comparable efficacies. Flumazenil-a GABAA receptor antagonist-did not reverse the onset or duration of convulsions produced by the extract in the picrotoxin-induced seizure model. In isoniazid-induced seizure, CPE (300 mg kg1, p.o.) significantly (p < 0.001) delayed the onset of seizure in mice and prolonged latency to death in animals. Overall, the hydroethanolic leaf extract of Calotropis procera possesses anticonvulsant properties.

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.

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.

An Evaluation of the In Vitro Roles and Mechanisms of Silibinin in Reducing Pyrazinamide- and Isoniazid-Induced Hepatocellular Damage.

Tuberculosis remains a significant infectious lung disease that affects millions of patients worldwide. Despite numerous existing drug regimens for tuberculosis, drug-induced liver injury is a major challenge that limits the effectiveness of these therapeutics. Two drugs that form the backbone of the commonly administered quadruple antitubercular regimen, that is, pyrazinamide (PZA) and isoniazid (INH), are associated with such hepatotoxicity. Yet, we lack safe and effective alternatives to the antitubercular regimen. Consequently, current research largely focuses on exploiting the hepatoprotective effect of nutraceutical compounds as complementary therapy. Silibinin, a herbal product widely believed to protect against various liver diseases, potentially provides a useful solution given its hepatoprotective mechanisms. In our study, we identified silibinin's role in mitigating PZA- and INH-induced hepatotoxicity and elucidated a deeper mechanistic understanding of silibinin's hepatoprotective ability. Silibinin preserved the viability of human foetal hepatocyte line LO2 when co-administered with 80 mM INH and decreased apoptosis induced by a combination of 40 mM INH and 10 mM PZA by reducing oxidative damage to mitochondria, proteins, and lipids. Taken together, this proof-of-concept forms the rational basis for the further investigation of silibinin's hepatoprotective effect in subsequent preclinical studies and clinical trials.

A novel screening test to predict the developmental toxicity of drugs using human induced pluripotent stem cells.

In vitro human induced pluripotent stem (iPS) cells testing (iPST) to assess developmental toxicity, e.g., the induction of malformation or dysfunction, was developed by modifying a mouse embryonic stem cell test (EST), a promising animal-free approach. The iPST evaluates the potential risks and types of drugs-induced developmental toxicity in humans by assessing three endpoints: the inhibitory effects of the drug on the cardiac differentiation of iPS cells and on the proliferation/survival of iPS cells and human fibroblasts. In the present study, the potential developmental toxicity of drugs was divided into three classes (1: non-developmentally toxic, 2: weakly developmentally toxic and 3: strongly developmentally toxic) according to the EST criteria. In addition, the type of developmental toxicity of drugs was grouped into three types (1: non-effective, 2: embryotoxic [inducing growth retardation/dysfunction]/deadly or 3: teratogenic [inducing malformation]/deadly) by comparing the three endpoints. The present study was intended to validate the clinical predictability of the iPST. The traditionally developmentally toxic drugs of aminopterin, methotrexate, all-trans-retinoic acid, thalidomide, tetracycline, lithium, phenytoin, 5-fluorouracil, warfarin and valproate were designated as class 2 or 3 according to the EST criteria, and their developmental toxicity was type 3. The non-developmentally toxic drugs of ascorbic acid, saccharin, isoniazid and penicillin G were designated as class 1, and ascorbic acid, saccharin and isoniazid were grouped as type 1 while penicillin G was type 2 but not teratogenic. These results suggest that the iPST is useful for predicting the human developmental toxicity of drug candidates in a preclinical setting.

A comparison of hepatoprotective activity of Bacoside to Silymarin treatment against a combined Isoniazid and Rifampin-induced hepatotoxicity in female Wistar rats.

The liver is an important organ that plays a vital role in homeostasis maintenance and regulation. Any liver damage or injury caused by drugs or chemicals is called hepatotoxicity. Isoniazid and rifampin are drugs used separately to treat tuberculosis but have unique side effects and potential hepatotoxicity. The metabolism of isoniazid (INH) and rifampin (RIF) takes place in liver hence hepatotoxicity is the main cause of their continuous use. Bacoside was obtained from the plant Bacopa monnieri, a dammarene type triterpenoid saponin, found distributed throughout India. Bacoside has been used as a nerve tonic, a free radical scavenger, and antioxidant. It is known that the combined INH-RIF induced hepatotoxicity can be antagonized by maintaining hepatocyte membrane integrity in rats. Silymarin, an herbal drug, and its component silybin were reported to work as lipid peroxidation inhibitors and antioxidants which scavenge free radicals. Due to minimal toxicity and no adverse drug interactions, Silymarin is used to treat various medically confirmed hepatic disorders. The aim of this study was to evaluate the beneficial effect of Bacoside against INH- and RIF-induced toxicity in livers of Wistar albino rats. Four experimental groups of rats were used to study four parameters; bodyweight, liver enzyme markers, liver antioxidant, and liver histopathology. INH- and RIF-treated rats showed abnormalities in liver markers which were normalized by Bacoside and that seems similar to the normal control and Silymarin-treated groups. Thus, the current study demonstrated the hepatoprotective effect of Bacoside against INH- and RIF-induced toxicity in Wistar albino rats.

Aqueous Extract of Wood Ear Mushroom, Auricularia polytricha (Agaricomycetes), Demonstrated Antiepileptic Activity against Seizure Induced by Maximal Electroshock and Isoniazid in Experimental Animals.

Auricularia polytricha is a popular mushroom found all over the world. This article describes a study of the antiepileptic effect of A. polytricha, a mushroom that is used traditionally for treating asthma, rheumatism, tumors, cough, fever, and epilepsy, and for its antimicrobial effect. We carried out toxicity studies to identify a standard dose of A. polytricha aqueous extract; maximal electroshock (MES)- and isoniazid (INH)-induced seizures in albino mice were used to screen for the extract's antiepileptic activity. Per Organisation for Economic Co-operation and Development Guideline 423, up to 2000 mg/kg body weight of extract was toxic. Animals were treated with aqueous extract at doses of 200, 400, and 600 mg/kg body weight. Phenytoin was used as the reference anticonvulsant drug for comparison. The investigation found a significant interruption in INH-induced clonic seizure. During MES, we found a reduction in the period of hind leg extensor phase; mice exhibited a significant decrease in the duration of hind limb extension after being treated with 400 and 600 mg/kg doses of A. polytricha. Comparable results were obtained in the INH group, as the extract seemed to delay the onset of a clonic seizure. The aqueous extract of A. polytricha showed antiepileptic action against MES- and INH-induced epilepsy in the mice. This extract, however, requires additional study in order to completely explain its active ingredients and their mechanisms of action.

Hepatoprotective activity of Tamarindus indica Linn stem bark ethanolic extract against hepatic damage induced by co-administration of antitubercular drugs isoniazid and rifampicin in Sprague Dawley rats.

Background Development of drug-induced hepatic damage (DIHD) during chemotherapy is the most common reason for interruption in chemotherapy. This study evaluated the hepatoprotective activity of the ethanolic extract of Tamarindus indica stem bark (EETI) against the induced DIHD in Sprague Dawley rats. Methods The rats were divided into five groups (n=5). Group I, group III, group IV, and group V rats received 1 mL 1% carboxymethyl cellulose, EETI 100 mg/kg body weight (b.wt), EETI 200 mg/kg b.wt, and silymarin 100 mg/kg b.wt, respectively, orally once every day for 28 days. After 1 h-group II, group III, group IV, and group V rats were administered with isoniazid (INH) and rifampicin (RIF) 50 mg/kg b.wt each orally once every day for 28 days. Then, 24 h after the last dosing, blood was withdrawn from the rats and analyzed for liver specific enzymes and biochemical markers. They were examined for histopathology. Results Co-administration of INH and RIF in group II significantly increased alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, serum bilirubin, and cholesterol levels while reduced the total protein and albumin levels compared to that of group I. EETI in group III and group IV rats significantly restored the liver specific enzymes and biochemical markers altered due to co-administration of INH and RIF to normal in a dose-dependent manner. EETI 200 mg/kg b.wt showed better protection to liver than EETI 100 mg/kg b.wt and was comparable to silymarin 100 mg/kg b.wt. It was well supported with histopathology of liver tissues. Conclusions EETI possesses hepatoprotective activity against DIHD in rats. It may have a substantial impact on developing clinical strategies to treat patients with hepatic damage.

Hot aqueous leaf extract of Lasianthera africana (Icacinaceae) attenuates rifampicin-isoniazid-induced hepatotoxicity.

OBJECTIVES: The aim of this study is to evaluate the hepatoprotective effect of Lasianthera africana (Icacinaceae) against isoniazid (INH) and rifampicin (RIF)-induced liver damage in rats. METHODS: The hepatoprotective effects of hot aqueous L. africana (HALA) leaf extract (0.1-1 g/kg) and silymarin (50 mg/kg) were assessed in a model of oxidative liver damage induced by RIF and INH (100 mg/kg each) in Wistar rats for 28 days. Biochemical markers of hepatic damage such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were assessed. The antioxidant statuses of plasma glutathione peroxidase (GSPx), glutathione reductase (GSH), catalase (CAT) and superoxide dismutase (SOD) and lipid peroxidation were evaluated. RESULTS: The pretreatment of INH and RIF decreased hematological indices and the antioxidant levels (P < 0.001) and increased the levels of liver marker enzymes (P < 0.001). However, pretreatment with HALA extract and silymarin provoked significant elevation of hematological indices. The levels of AST, ALT, and ALP were depressed (P < 0.001). Total triglycerides, total cholesterol, total bilirubin and low-density lipoprotein were decreased (P < 0.001). However, high-density lipoprotein, bicarbonate, and electrolytes like chloride and potassium were elevated (P < 0.001), but sodium was depressed (P < 0.05). Additionally, GSH, GSPx, SOD and CAT were elevated (P < 0.01) and malondialdehyde was depressed (P < 0.001) when compared to the RIF-INH-treated rats. Histopathological evaluations support hepatoprotective activity. CONCLUSION: This study demonstrated that HALA leaf extract attenuated RIF-INH-induced hepatotoxicity. L. africana could be exploited in management of RIF-INH-induced hepatitis.

Modulation of pregnane X receptor (PXR) and constitutive androstane receptor (CAR) activation by ursolic acid (UA) attenuates rifampin-isoniazid cytotoxicity.

BACKGROUND: Interactions between transcriptional inducers of cytochrome P450 (CYP450) enzymes and therapeutic drugs may be prevented by antagonizing the activation of a nuclear receptor (NR), pregnane X receptor (PXR, NR1I2), thus improving therapeutic efficacy. PURPOSE: In the present study, we aim to identify that ursolic acid (UA), a widely distributed pentacyclic triterpene, may act as an effective antagonist of PXR and its sister NR receptor, constitutive androstane receptor (CAR, NR1I3). METHODS: The hepatocellular carcinoma cell line, HepG2, was used to evaluate the promoter activity of PXR and CAR target genes, CYP3A4 and CYP2B6, respectively. Catalytic activities, mRNA, and protein expression of CYP3A4 and CYP2B6 were evaluated in a differentiated HepaRG cell line. Coregulation of PXR with coregulators on CYP3A4 promoter response elements was also been characterized. RESULTS: Transient transfection assays showed that UA effectively attenuated CYP3A4 and CYP2B6 promoter activities mediated by rifampin (RIF, human PXR agonist) and CITCO (human CAR agonist). These inhibitory effects were well correlated with the expression and catalytic activities of CYP3A4 and CYP2B6. Furthermore, the interaction of co-regulators with PXR and the transcriptional complexes in the CYP3A4 promoter activity and CYP3A4 promoter xenobiotic response element (everted repeat 6, ER6), respectively, were disrupted in the presence of UA. UA showed an antagonistic effect against PXR, and reversed the cytotoxic effects of isoniazid (INH) induced by RIF. Taken together, these results show that UA inhibits the transactivation effects of PXR and CAR, and reduces the expression and function of CYP3A4 and CYP2B6. CONCLUSION: The present study suggests that UA could be a powerful agent for reducing potentially dangerous interactions between transcriptional inducers of CYP enzymes and therapeutic drugs.

Toxicological profile of IQG-607 after single and repeated oral administration in minipigs: An essential step towards phase I clinical trial.

IQG-607 is an anti-tuberculosis drug candidate, with a promising safety and efficacy profile in models of tuberculosis infection both in vitro and in vivo. Here, we evaluated the safety and the possible toxic effects of IQG-607 after acute and 90-day repeated administrations in minipigs. Single oral administration of IQG-607 (220 mg/kg) to female and male minipigs did not result in any morbidity or mortality. No gross lesions were observed in the minipigs at necropsy. Repeated administration of IQG 607 (65, 30, or 15 mg/kg), given orally, for 90 days, in both male and female animals did not cause any mortality and no significant body mass alteration. Diarrhea and alopecia were the clinical signs observed in animals dosed with IQG-607 for 90 days. Long-term treatment with IQG-607 did not induce evident alterations of blood cell counts or any hematological parameters. Importantly, the repeated schedule of administration of IQG-607 resulted in increased cholesterol levels, increased glucose levels, decrease in the globulin levels, and increased creatinine levels over the time. Most necropsy and histopathological alterations of the organs from IQG-607-treated groups were also observed for the untreated group. In addition, pharmacokinetic parameters were evaluated. IQG-607 represents a potential candidate molecule for anti-tuberculosis drug development programs. Its promising in vivo activity and mild to moderate toxic events detected in this study suggest that IQG-607 represents a candidate for clinical development.

Adverse effects of anti-tuberculosis drugs on HepG2 cell bioenergetics.

Tuberculosis (TB) is an intractable chronic infection. Disease treatment with anti-TB drugs remains challenging due to drug-induced hepatotoxicity. The toxicity of the anti-TB drugs rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA) either alone or in combination was investigated in HepG2 cells. Assays of intracellular adenosine triphosphate (ATP) levels at 4-, 24- and 48-h post-exposure to gradient concentrations of RIF, INH and PZA were conducted. Drug-induced effects on mitochondrial membrane potential (MMP), mitochondrial complex I and complex III activity, nicotinamide adenine dinucleotide (NAD+) levels and cellular lactate production were assessed. Decreased ATP levels were dose-dependent and correlated with drug exposure duration. Approximate 24-h IC50s were 0.5 mM, 70 mM and 84 mM for RIF, INH and PZA, respectively. Twenty-four hours post-drug treatment, reductions of MMP ( p = 0.0005), mitochondrial complex I and III activities ( p = 0.0001 and p = 0.0003, respectively), NAD+ levels ( p = 0.0057) and increased lactate production ( p < 0.0001) were observed. Drug combinations used to mimic cumulative drug treatments induced a synergistic inhibition of mitochondrial complex I activity. An assessment of cellular ultrastructure using transmission electron microscopy indicated drug-induced mitophagy. Collectively, our study suggests that hepatotoxicity of commonly employed anti-TB drugs is mediated by their curtailment of mitochondrial function.

The ameliorating effect of Centella asiatica ethanolic extract on albino rats treated with isoniazid.

BACKGROUND: Isoniazid, also called isonicotinyl hydrazine (INH), is a commonly used drug for treating tuberculosis. The main drawback is its toxic side effects. Centella asiatica has long been used in the Ayurvedic system of medicine owing to its wide medicinal properties. This study was designed to examine the effectiveness of C. asiatica ethanolic leaf extract (CA) on INH-treated albino rats. METHODS: The adverse effects induced by INH (50 mg/kg bw) administration on haematological parameters, oxidative status (thiobarbituric acid-reactive substances, superoxide dismutase, catalase, and reduced glutathione), liver and kidney function markers, and their amelioration by various concentrations of CA (20, 40, 60, and 100 mg/kg bw) or silymarin (SIL) (50 mg/kg bw, administered before 1 h of INH treatment for 30 days to rats) were studied. Moreover, histological studies were carried out in liver and kidney tissues of rats treated with the most effective concentration to further support the possible effectiveness of CA on INH-intoxicated rats. RESULTS: All the affected parameters returned to near-normal levels, and the effective concentration of extract was found to be 100 mg/kg bw. The histology of both the liver and the kidneys subsequently supported the effectiveness of CA (100 mg/kg bw). CONCLUSIONS: Altogether, the results suggest that CA at 100 mg/kg bw can substantially reduce the toxic effects of INH.

Zidovudine and isoniazid induced liver toxicity and oxidative stress: Evaluation of mitigating properties of silibinin.

HIV/AIDS patients are more prone for opportunistic TB infections and they are administered the combined regimen of anti-retroviral drug zidovudine (AZT) and isoniazid (INH) for therapy. However, AZT+INH treatment has been documented to induce injury and remedial measures to prevent this adversity are not clearly defined. Silibinin (SBN) is a natural hepatoprotective principle isolated from medicinal plant Silybum marianum and is currently used for therapy of various liver diseases. This study investigate the hepatotoxic potentials of AZT alone, INH alone and AZT+INH treatments and the mitigating potentials of SBN against these drugs induced toxic insults of liver in rats. Separate groups of rats (n=6 in each group) were administered AZT alone (50mg/kg b.w.), INH alone (25mg/kg, b.w.), AZT+INH (50mg/kg, b.w. and 25mg/kg, b.w.), SBN alone (100mg/kg, b.w.) and SBN+AZT+INH daily for sub-chronic period of 45days orally. The control rats received saline/propylene glycol. INH alone and AZT+INH-induced parenchymal cell injury and cholestasis of liver was evidenced by highly significant increase in the activities of marker enzymes (aspartate and alanine transaminase, alkaline phosphatase, argino succinic acid lyase), bilirubin, protein, oxidative stress parameters (lipid peroxidation, superoxide dismutase, catalase, reduced glutathione, vitamins C and E) and membrane bound ATPases were evaluated in serum/liver tissue homogenates. Histopathological studies show ballooning degradation, inflammatory lesions, lipid deposition and hydropic changes in the liver tissue. All the above biochemical and pathological changes induced by AZT+INH treatments were mitigated in rats receiving SBN simultaneously with these hepatotoxins, indicating its hepatoprotective and antioxidant potentials against AZT+INH-induced hepatotoxicity. The moderate hepatoprotective and oxidant potentials of SBN could be due to its low bioavailability and this deficiency could be prevented by supplementation of phosphatidylcholines and studies are warranted on these lines to improve the therapeutic efficiency of SBN.

Monoammonium glycyrrhizinate protects rifampicin- and isoniazid-induced hepatotoxicity via regulating the expression of transporter Mrp2, Ntcp, and Oatp1a4 in liver.

CONTEXT: Drug-induced liver injury (DILI) is associated with altering expression of hepatobiliary membrane transporters. Monoammonium glycyrrhizin (MAG) is commonly used for hepatic protection and may have a correlation with the inhibition effect of multidrug resistance-associated protein 2 (Mrp2). OBJECTIVE: This study evaluates the dynamic protective effect of MAG on rifampicin (RIF)- and isoniazid (INH)-induced hepatotoxicity in rats. MATERIALS AND METHODS: Male Wistar rats were randomly divided into four groups of 15 rats. Liver injury was induced by co-treatment with RIF (60 mg/kg) and INH (60 mg/kg) by gavage administration; MAG was orally pretreated at the doses of 45 or 90 mg/kg 3 h before RIF and INH. Rats in each group were sacrificed at 7, 14, and 21 d time points after drug administration. RESULTS: Liver function, histopathological analysis, and oxidative stress factors were significantly altered in each group. The expression of Mrp2 was significantly increased 230, 760, and 990% at 7, 14, and 21 time points, respectively, in RIF- and INH-treated rats. Compared with the RIF and INH groups, Mrp2 was reduced and Ntcp was significantly elevated by 180, 140, and 160% in the MAG high-dose group at the three time points, respectively. The immunoreaction intensity of Oatp1a4 was increased 170, 190, and 370% in the MAG low-dose group and 160, 290, and 420% in the MAG high-dose group at the three time points, respectively, compared with the RIF and INH groups. DISCUSSION AND CONCLUSION: These results indicated that MAG has a protective effects against RIF- and INH-induced hepatotoxicity. The underlying mechanism may have correlation with its effect on regulating the expression of hepatobiliary membrane transporters.

Circadian variation in murine hepatotoxicity to the antituberculosis agent «Isoniazide¼.

The circadian time is an important process affecting both pharmacokinetics and pharmacodynamics of drugs. Consequently, the desired and/or undesired effects vary according to the time of drug administration in the 24 h scale. This study investigates whether the toxicity in liver as well as oxidative stress varies according to the circadian dosing-time of isoniazid (INH) in mice. A potentially toxic INH dose (120 mg/kg) was injected by i.p. route to different groups of animals at three different circadian times: 1, 9, and 17 Zeitgeber time (ZT). INH administration at 1 ZT resulted in a maximum hepatotoxicity assessed by the significant increase in both serum transaminase (ALAT: alanine aminotransferase) and (ASAT: aspartate aminotransferase) and antioxidant enzyme activities (catalase: CAT and superoxide dismutase: SOD). The highest malondialdehyde (MDA) level indicating an induction of lipid peroxidation resulting in oxidative damage was also observed at 1 ZT. Liver histopathology from INH groups at 9 ZT and at 1 ZT showed moderate to severe cytoplasma vacuolation, hepatocyte hypertrophy, ballooning, and necrosis. The circadian variation in INH toxicity may help realize a chronotherapy protocol in humans based on the selection of the best time associated to optimal tolerance or least side effects.