Effect of garlic on isoniazid and rifampicin-induced hepatic injury in rats

Deciphering the emerging role of phytocompounds: Implications in the management of drug-resistant tuberculosis and ATDs-induced hepatic damage

Tuberculosis is a disease of poverty, discrimination, and socioeconomic burden. Epidemiological studies suggest that the mortality and incidence of tuberculosis are unacceptably higher worldwide. Genomic mutations in embCAB, embR, katG, inhA, ahpC, rpoB, pncA, rrs, rpsL, gyrA, gyrB, and ethR contribute to drug resistance reducing the susceptibility of Mycobacterium tuberculosis to many antibiotics. Additionally, treating tuberculosis with antibiotics also poses a serious risk of hepatotoxicity in the patient's body. Emerging data on drug-induced liver injury showed that anti-tuberculosis drugs remarkably altered levels of hepatotoxicity biomarkers. The review is an attempt to explore the anti-mycobacterial potential of selected, commonly available, and well-known phytocompounds and extracts of medicinal plants against strains of Mycobacterium tuberculosis. Many studies have demonstrated that phytocompounds such as flavonoids, alkaloids, terpenoids, and phenolic compounds have antibacterial action against Mycobacterium species, inhibiting the bacteria's growth and replication, and sometimes, causing cell death. Phytocompounds act by disrupting bacterial cell walls and membranes, reducing enzyme activity, and interfering with essential metabolic processes. The combination of these processes reduces the overall survivability of the bacteria. Moreover, several phytochemicals have synergistic effects with antibiotics routinely used to treat TB, improving their efficacy and decreasing the risk of resistance development. Interestingly, phytocompounds have been presented to reduce isoniazid- and ethambutol-induced hepatotoxicity by reversing serum levels of AST, ALP, ALT, bilirubin, MDA, urea, creatinine, and albumin to their normal range, leading to attenuation of inflammation and hepatic necrosis. As a result, phytochemicals represent a promising field of research for the development of new TB medicines.

Flavonoids of Chromolaena odorata (L.) R.M.King & H.Rob. as potential leads for treatment against tuberculosis

Tuberculosis (TB) is currently rated as the 13th leading cause of mortality and the second leading cause of death after COVID-19, and above AIDS. Existing challenges relating to the development of multidrug-resistant strains and dangerous side effects of currently used drugs add impetus to the search for additional TB treatments. Hence, interest has grown in the use of medicinal plants as a source of bioactive preparations with efficacy against TB-causing organisms, and also with the ability to ameliorate the negative effects of TB drugs. This study aimed to evaluate the antimycobacterial and hepatoprotective potentials of extracts and isolated flavonoid compounds from invasive Chromolaena odorata. Test organisms used were pathogenic Mycobacterium bovis and M. tuberculosis H37RV, and the fast-growing M. aurum, M. fortuitum and M. smegmatis. The selectivity index (SI) values of the test substances were determined through cytotoxicity assays to promote these extracts and compounds as leads for the development of effective and safe anti-tubercular drugs. The antimycobacterial activity was evaluated using a serial microdilution method, and the SI was calculated from the 50% lethal concentrations calculated from cytotoxicity tests. Hepatoprotective activity was determined using HepG2 liver cells treated with rifampicin as a toxin. The extracts and compounds had a range of antimycobacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.031 to 2.5 mg/mL. Two flavonoid compounds, 5,7,4'-trimethoxy flavanone and 5‑hydroxy-3,7,4'-trimethoxyflavone showed promising antimycobacterial potential, and minimal toxicity was observed, as most SI values were higher than 1. The flavonoid compound 5,7,4'-trimethoxy flavanone had the highest SI (6.452), which was against M. tuberculosis H37RV. The HepG2 cells were reduced to 65% due to toxicity by rifampicin, however, the flavonoid compounds were able to improve cell viability to between 81 and 89% at different concentrations tested. Results obtained indicate that C. odorata may serve as a lead for the development of safe and effective antimycobacterial and hepatoprotective drugs.

The Effectiveness of Silymarin in the Prevention of Anti-tuberculosis Drug-induced Hepatotoxicity: A Randomized Controlled Clinical Trial

Background

Several animal studies have shown the protective effect of silymarin (the extract of Silybum marianum seeds) against anti-tuberculosis drug-induced hepatotoxicity (ATDH). However, the knowledge of ATDH of silymarin in humans is scarce. In this study, we aimed to clinically evaluate it.

Methods

During this randomized controlled clinical trial, 36 new cases of tuberculosis (TB) were enrolled to receive either silymarin 150 mg twice daily for two weeks along with a standard anti-TB therapeutic regimen (experimental group; n = 16) or standard anti-TB therapeutic regimen alone (control group; n = 21). Liver function tests (serum AST, ALT, ALP, and total bilirubin) at the end of weeks 1 and 2 as well as the rate of ATDH during the study were determined and compared between the groups.

Results

No significant differences between the experimental and control groups were observed at the end of the first week regarding liver function tests; However, at the end of the second week, the mean serum levels of AST (P = 0.03) and ALP (P = 0.04) were significantly lower in the experimental group. ALT (P = 0.016) and ALP (P = 0.027) levels in the experimental group significantly decreased during the study, while the changes in the control group were not significant. Two patients in the control group (9.5%) developed ATDH, while no one in the experimental group manifested this adverse effect.

Conclusions

Our study suggests that silymarin use has the potential for the reduction of anti-TB drug-induced hepatotoxicity.

The chemoprevention of spirulina platensis and garlic against diethylnitrosamine induced liver cancer in rats via amelioration of inflammatory cytokines expression and oxidative stress

Natural antioxidant products play a vital role in the treatment and prevention of cancer disease because they have no side effects. This study aimed to compare the chemoprotective effect of Spirulina platensis (SP) and garlic against hepatocellular carcinoma (HCC) in rats. This study was being done by using 60 male Wistar rats and divided into four groups. Group (I): normal group. Group (II): HCC group induced by injection of a single dose of DEN (200 mg/kg/I.P) and after 14 days injected CCl4 (1 mg/kg/I.P) 3 times/week/six weeks. Group (III): HCC group received SP orally at a dose (500 mg/kg). Group (IV): HCC group received garlic (250 mg/kg) orally. The results revealed that the Spirulina and garlic treatment have a significant decrease in Glutamate pyruvate transaminase, Glutamate oxaloacetate transaminase, GGT, LDH, and the Malondialdehyde (MDA) activity, and furthermore, a significant increase in the total protein level, the superoxide dismutase (SOD), and Catalase (CAT) activity nearly to normal activity. Furthermore, the hepatic expression of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), inducible nitric oxide synthase, transforming growth factor-beta (TGF-β1), Heat Shock Protein glycoprotein 96 (HSPgp96), and Glypican 3 (GP3) were down regulated by the Spirulina and garlic treatment in comparison with those in HCC group. All findings reported that the chemoprotective of both Spirulina and garlic that have nearly the same effect may be due to antioxidant activity and inhibition of lipid peroxidation, amelioration of pro-inflammatory cytokine, HSPgp96, and GP3.

Garlic Extract Alleviates Trastuzumab-Induced Hepatotoxicity in Rats Through Its Antioxidant, Anti-Inflammatory, and Antihyperlipidemic Effects

Background

Trastuzumab is a new biological drug that has been used to treat breast and gastric cancer; however, its cardiotoxicity and hepatotoxicity limit its use. Garlic has antioxidant, anti-inflammatory, antihyperlipidemic, and anticancer effects. The present study aimed to evaluate the effects of garlic on trastuzumab-induced hepatotoxicity in a rat model.

Methods

Twenty rats were divided into four equal groups as vehicle control (G1), garlic (G2), trastuzumab (G3), and trastuzumab+garlic (G4). All rats were sacrificed after eight weeks of treatment, followed by blood collection and excision of liver tissues for further analyses. The liver specimens were processed for histopathological (HP), immunohistochemical (expression of TNF-α and PCNA), immunofluorescent expression of Chk2 and p53, biochemical, and flow cytometry investigations to evaluate the extent of hepatocyte injury. The biochemical analysis was conducted for the activity of tissue antioxidants (GPX1, CAT, and SOD2), serum lipid profile, and liver enzymes, whereas ROS was performed by flow cytometry.

Results

The results revealed remarkable structural changes in hepatocytes of G3 with significant increases in the numbers of inflammatory cells and positive PCNA cells, area % of collagen fibers, and immuno-expression of TNF-α, as well as a significant reduction in the nuclear expression of Chk2. In addition, significant reductions were noticed in the antioxidant enzymes (SOD2, CAT, and GPX1) activity of G3. In contrast, the levels of lipid profile tests (triglycerides, total cholesterol, LDLC, and HDLC), liver enzymes (ALT, AST, and ALP), and ROS revealed significant increases in rats of G3. Likewise, garlic administration in G4 restored all mentioned changes to their average levels deviated by trastuzumab.

Conclusion

Based on the current results, garlic demonstrates hepatoprotective effects against trastuzumab-induced toxicity in rats. The study suggested for the first time that the coadministration of garlic with trastuzumab for treating breast or gastric cancer can augment their efficacy with minimal toxicity.

Effects of co-administration of Unani pharmacopoeia formulations Qurs Tabasheer Sartani and Arq Hara Bhara with CAT-I antitubercular drugs in rats

OBJECTIVES

Tuberculosis continues to be a major public health problem globally, despite incredible advancements in healthcare system. In Unani system of medicine, Qurs Tabasheer Sarthani (QTS) and Arq Hara Bhara (AHB) have been traditionally used for tuberculosis like conditions. The study was aimed to investigate the effects of co-administration of QTS and AHB with category I first line antitubercular drugs (CAT-I) on the indices of liver and kidney function in rats.

METHODS

QTS and AHB were prepared individually and mixed to achieve final compound Unani pharmacopoeia formulation (UPF). The human equivalent doses for rats were calculated and administered with and without CAT-I. The effects of the formulations on serum indices of kidney and liver function, hematological markers and plasma CAT-I drug levels were estimated at 14th, 60th & 180th days of treatment.

RESULTS

The administration of UPF, CAT-I and UPF + CAT-I altered the levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT) and haematological markers. These alterations were within permissible range and randomly distributed among groups during various time points. Administration of CAT-I alone resulted in moderate histopathological changes which were completely abrogated in CAT-I + UPF co-administered animals. The co-administration of UPF with CAT-I improved the plasma peak rifampicin (RIF) levels, without altering the liver and kidney functions.

CONCLUSIONS

The co-administration of UPF with ATT improved liver and kidney functions and increased the plasma levels of RIF. These beneficial findings provide a scope to evaluate the pharmacokinetic studies in humans.

Attenuated Renal and Hepatic Cells Apoptosis Following Swimming Exercise Supplemented with Garlic Extract in Old Rats

Background/Objective

One of the problems associated with aging is the development of apoptosis in different tissues. There is evidence that physical activity and herbal remedies can be useful. This study aimed to determine the effect of swimming training (SW) alone or combined with garlic extract on renal and hepatic cells apoptosis, as wellas on the liver and kidney function biomarkers in old rats.

Methods

A total of 35 old rats (aged 40–50 weeks) were randomly divided into 5 groups including control, saline (S), exercise training (ET), garlic (G) and exercise training+ garlic (ET.G) groups. Exercise was started for 5 min/day and then gradually extended to 60 min/day and the G and E+G groups received 1 mL/kg of this mixture by gavage. Twenty-four hours after completion of 8 weeks training, liver, kidney and blood samples were collected for histopathological examinations, liver and kidney functions, oxidative stress and apoptosis biomarkers.

Results

The tissue sections of the SW exercise, control and saline groups showed some mild histopathological changes in liver and kidney, while SW supplemented with garlic prevented these damages. The SW alone or supplemented with garlic significantly increased the Bcl-2 value and declined the BAX level in both liver and kidney (p<0.05). The activities of catalase (CAT) and superoxide dismutase (SOD) in the liver and kidney of the control and saline groups were lower than those in E, G and G+E groups, while a significant increase for malondialdehyde (MDA) value was found in the control and saline groups. Furthermore, the E+G significantly declined the activity of hepatic (ALT, AST and ALP) and renal damage (uric acid, urea and creatinine) biomarkers compared to the control and saline groups (p<0.05).

Discussion

Swimming exercise supplemented with garlic extract not only improves antioxidant capacity but also declines oxidative damages and apoptosis through reducing Bax levels and enhancing Bcl-2 value.

Phytochemical analysis and Evaluation of hepatoprotective effect of Maytenus royleanus leaves extract against anti-tuberculosis drug induced liver injury in mice

BACKGROUND

Myrin®-p Forte is an anti-tuberclosis agent that can cause hepatic injuries in clinical settings. Maytenus royleanus (Celastraceae) is a medicinal plant, possesses antioxidant and anticancer activities. The hepatoprotective effect of the methanol extract of Maytenus royleanus leaves (MEM) against Myrin®-p Forte induced hepatotoxicity in mice was investigated.

METHODS

Mice were randomly parted into six groups (n = 6). Fixed-dose combination of Myrin®-p Forte (13.5 mg/kg Rifampicin, 6.75 mg/kg Isoniazid, 36.0 mg/kg Pyrazinamide and 24.8 mg/kg Ethambutol; RIPE] was administered for 15 days to induce liver injury. In treatment groups MEM (200 mg/kg and 400 mg/kg doses) and Vitamin B6 (180mg/kg) were administered prior to RIPE. Control group received 2% DMSO. Serum liver function tests, DNA damage, tissue antioxidant enzymes and histopathological alterations were studied. HPLC analysis was performed to determine the chemical composition using standard compounds.

RESULTS

The quercitin, gallic acid, luteolin, viteixin, apigenin, kaempherol, hyperoside and myricetin contents of all samples were determined by reverse-phase HPLC. Quercetin (0.217 mg/g dry weight) and luteolin (0.141 mg/g dry weight) were the major flavonoids identified in MEM. Myrin®-p Forte markedly (p < 0.05) deteriorated lipid profile and upregulated the concentration of LDH, AST, ALP, ALT and γ-GT in serum along with DNA fragmentation (37.13 ± 0.47%) and histopathological injuries in hepatic tissues of mice compared with the control group. Myrin®-p Forte increased (p < 0.001) lipid peroxidation and H₂O₂ while decreased (p < 0.001) the activity level of CAT, SOD, POD, GPx, GST, GSR, γ-GT and GSH. Co-administration of MEM (200 mg/kg; 400 mg/kg) or the vitamin B6 (180 mg/kg) to Myrin®-p Forte administered mice significantly ameliorated LDL, cholesterol, HDL and triglyceride content. Furthermore, MEM dose dependently corrected serum liver function tests, decrease % DNA fragmentation (17.82 ± 0.35 and 7.21 ± 0.32 respectively), DNA damage. MEM treated protect RIPE induced oxidative damage by enhancing antioxidants to oxidants balance. Histological examination comprehends biochemical findings.

CONCLUSION

The antioxidant effects of MEM exerted the hepatoprotective potential against the Myrin®-p Forte induced hepatotoxicity in mice.

Protective effect of pyrrolidine dithiocarbamate on isoniazid/rifampicin‑induced liver injury in rats

Isoniazid (INH) and rifampicin (RIF) continue to be first line anti‑tuberculosis (TB) drugs. However, the use of these drugs is associated with hepatotoxicity. Nuclear factor‑κB (NF‑κB) plays a crucial role in regulating immunity and inflammation. It has been reported that pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF‑κB, exerts a hepatoprotective effect on acute and chronic liver damage. The aim of the present study was to explore the INH/RIF‑induced protective effects and mechanisms of PDTC on liver injury. Rats were intragastrically administered INH (50 mg/kg/day) and RIF (50 mg/kg/day) daily for 28 days. PDTC (50 mg/kg/day) was intraperitoneally injected 2 h after the co‑administration of INH and RIF to compare liver biochemical indicators in the serum, histopathological damage, NF‑κB activity, oxidative stress, hepatic mRNA expression of tumor necrosis factor (TNF)‑α, bile salt export pump (BSEP), and protein expression of BSEP. It was found that the inhibition of NF‑κB activation by PDTC treatment markedly alleviated liver biochemical and histological injury, decreased oxidative stress and mRNA levels of TNF‑α, and prevented decreases in BSEP mRNA and protein expression induced by the co‑administration of INH and RIF. Collectively, the present data suggested that INH/RIF‑induced liver injury is dependent on the activation of NF‑κB. PDTC exerted a therapeutic effect on INH/RIF‑induced liver injury by increasing BSEP expression, and exhibiting antioxidant and anti‑inflammatory activities.

Telfairia occidentalis (Cucurbitaceae) pulp extract mitigates rifampicin-isoniazid-induced hepatotoxicity in an in vivo rat model of oxidative stress

OBJECTIVE

Drug-induced liver injury complicates antituberculosis drug treatment and is a leading cause of death worldwide. The aim of this study is to establish the ethnomedicinal claim of hepatoprotective effects of fruit pulp extract of Telfairia occidentalis against rifampicin (RIF) and isoniazid (INH)-induced oxidative stress in rats.

METHODS

T. occidentalis pulp extract (TOPE) (125-500 mg/kg) and silymarin (50 mg/kg) were evaluated in an induced hepatotoxicity model of oxidative stress in Wistar rats by intoxication with RIF and INH (100 mg/kg each) orally for 60 d. Markers indicating oxidative stress and hepatic damage such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were assessed. Biomarkers of antioxidant status, including catalase, glutathione reductase, glutathione peroxidase and superoxide dismutase, and marker of lipid peroxidation, malondialdehyde (MDA), were assayed using standard procedures. The hematological profile, lipid profile, serum markers for kidney function and histopathological examination were also assessed.

RESULTS

Intoxication with RIF and INH markedly reduced the hematological indices and elevated the biochemical enzyme markers (AST, ALT and ALP, P < 0.001) and lipid profile (P < 0.001), while antioxidant biomarkers were significantly (P < 0.01) depressed and MDA was elevated. However, pretreatment with TOPE significantly (P < 0.001) alleviated this alteration and sustained the antioxidant potentials. The histopathological morphology supports the biochemical evidence of hepatoprotection.

CONCLUSION

Current study is indicative of potential antioxidant activity, hepatoprotective effects and plausible therapeutic alleviation of RIF-INH-induced hepatotoxicity of TOPE in laboratory animals.

First-line antituberculosis drugs disrupt endocrine balance and induce ovarian and uterine oxidative stress in rats

BACKGROUND

The first-line antituberculosis (anti-TB) drugs, isoniazid (INH), rifampicin (RIF), ethambutol (EMB), and pyrazinamide (PZA), are effective in the treatment of pulmonary tuberculosis. However, the toxicity of these drugs in the clinical setting limits their use. Here, we evaluated the effects of anti-TB drugs on the reproductive system in female rats.

METHODS

Thirty-five female Wistar rats were assigned into five groups of seven animals each. The control group received normal saline, whereas others received INH (5 mg/kg), RIF (10 mg/kg), EMB (15 mg/kg), and PZA (15 mg/kg) through gavage thrice a week for 8 consecutive weeks.

RESULTS

Administration of anti-TB drugs significantly (p<0.05) reduced uterine and ovarian weight, as well as the relative weight of the uterus when compared with controls. In addition, anti-TB drugs increased the activities of alanine aminotransferase as well as the level of total bilirubin. Treatment with INH, RIF, and PZA significantly (p<0.05) reduced the levels of follicle-stimulating and luteinizing hormones, estrogen, and prolactin. The INH, RIF, EMB, and PZA caused significant (p<0.05) increases in uterine malondialdehyde (MDA) levels by 281%, 214%, 273% and 190%, respectively, whereas INH and EMB increased the ovarian malondialdehyde by 111% and 129%, respectively. These drugs significantly (p<0.05) decreased the activities of ovarian glutathione-S-transferase and uterine glutathione peroxidase, superoxide dismutase, and catalase. Histology revealed the erosion of uterine mucosa, debris in the lumen of the uterus, congestion, and underdeveloped follicles in ovaries.

CONCLUSIONS

The first-line anti-TB drugs elicited reproductive toxicity in the uterus and ovaries of rats through mechanisms that involved oxidative stress.

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.

Drug-Induced Liver Toxicity and Prevention by Herbal Antioxidants: An Overview

The liver is the center for drug and xenobiotic metabolism, which is influenced most with medication/xenobiotic-mediated toxic activity. Drug-induced hepatotoxicity is common and its actual frequency is hard to determine due to underreporting, difficulties in detection or diagnosis, and incomplete observation of exposure. The death rate is high, up to about 10% for drug-induced liver damage. Endorsed medications represented >50% of instances of intense liver failure in a study from the Acute Liver Failure Study Group of the patients admitted in 17 US healing facilities. Albeit different studies are accessible uncovering the mechanistic aspects of medication prompted hepatotoxicity, we are in the dilemma about the virtual story. The expanding prevalence and effectiveness of Ayurveda and natural products in the treatment of various disorders led the investigators to look into their potential in countering drug-induced liver toxicity. Several natural products have been reported to date to mitigate the drug-induced toxicity. The dietary nature and less adverse reactions of the natural products provide them an extra edge over other candidates of supplementary medication. In this paper, we have discussed the mechanism involved in drug-induced liver toxicity and the potential of herbal antioxidants as supplementary medication.

Circadian variation in murine hepatotoxicity to the antituberculosis agent «Isoniazide»

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.

A double-blinded randomized controlled trial of silymarin for the prevention of antituberculosis drug-induced liver injury

Background

Hepatitis is a common adverse effect of antituberculosis drugs. Silymarin prevented drug-induced hepatoxicity in animals with anti-oxidative mechanisms but its effect in human has been unknown. We aimed to evaluate the efficacy of silymarin for preventing antituberculosis-drug induced liver injury (antiTB-DILI) in patients with tuberculosis.

Methods

A double-blind randomized placebo-controlled trial was performed. Tuberculosis patients were randomly allocated to receive placebo or silymarin. The outcomes of interests were antiTB-DILI and the maximum liver enzymes at week 4. Antioxidative enzymes (i.e., superoxide dismutase (SOD), glutathione and malondialdehyde assays) were assessed. The risks of antiTB-DILI between the two groups were compared. A number need to treat was estimated.

Results

A total of 55 out of 70 expected numbers of patients were enrolled. There were 1/27 (3.7 %) and 9/28 (32.1 %) patients who developed antiTB-DILI in the silymarin and the placebo groups. Risk reduction was 0.28 (0.10, 0.47), i.e., receiving silymarin was 28 % at lower risk for antiTB-DILI than placebo. This led to prevention of 28 patients from being antiTB-DILI among 100 treated patients. Median (IQR) of ALT levels at week 4 in the placebo and the silymarin group were 35.0 (15, 415) IU/L and 31.5 (20, 184) IU/L (p = 0.455). The decline of SOD level at week 4 in the silymarin group was less than the placebo group (p < 0.027).

Conclusions

Silymarin reduced the incidence of antiTB-DILI. The benefit of silymarin may be explained from superoxide dismutase restoration. Larger clinical trials are required to confirm the result of our small study [Clinicaltrials.Gov Identifier Nct01800487].

Hepatoprotective agent tethered isoniazid for the treatment of drug-induced hepatotoxicity: Synthesis, biochemical and histopathological evaluation

The aim of the study was to investigate the protective effect of isoniazid–curcumin conjugate (INH–CRM) in INH-induced hepatic injury by biochemical analysis and histology examination of liver in Wistar rats. The biochemical analysis included determination of the levels of plasma cholesterol, triglycerides (TG), albumin content, and lipid peroxidation (MDA). INH–CRM administration resulted in a significant decrease in plasma cholesterol, TG, and MDA levels in the liver tissue homogenate with an elevation in albumin level indicating its hepatoprotective activity. Histology of the liver further confirmed the reduction in hepatic injury. The hepatoprotective with INH–CRM can be attributed to the antioxidant activity of curcumin. The conjugate probably stabilizes the curcumin molecule, preventing its presystemic metabolism thereby enhancing its bioavailability and therefore, its hepatoprotective activity. Thus, the novel INH–CRM has the potential to alleviate INH-induced liver toxicity in antitubercular treatment.

Carnitine for prevention of antituberculosis drug-induced hepatotoxicity: a randomized, clinical trial

BACKGROUND AND AIM

In the present study, the potential benefits of oral carnitine in preventing antituberculosis drug-induced hepatotoxicity (ATDH) were evaluated.

METHODS

Fifty-four patients in the carnitine and 62 patients in the placebo group completed the study. The carnitine group received 1000 mg oral carnitine solution twice daily for 4 weeks. The placebo group received 10 mL of oral placebo solution twice daily for 4 weeks. ATDH was defined as an increase in the serum level of aspartate aminotransferase or alanine aminotransferase greater than three or five times of the upper limit of normal with or without clinical symptoms of hepatotoxicity, respectively.

RESULTS

During the study period, 29 (25%) patients experienced ATDH. Among these patients, nine (16.7%) and 20 (32.3%) were in the carnitine and placebo groups, respectively (P = 0.049). Based on multivariate logistic regression model, age over 35 years old (odds ratio [OR] = 7.01, P = 0.002), human immunodeficiency virus infection (OR = 40.4, P < 0.001), diabetes mellitus (OR = 37.6, P = 0.001), and placebo treatment (OR = 0.1, P = 0.01) were identified as predisposing factors for ATDH.

CONCLUSION

Results of our preliminary clinical trial suggested that cotreatment with 2000 mg oral L-carnitine solution daily for 4 weeks significantly decreased the rate of ATDH.

Spirulina maxima Protects Liver From Isoniazid and Rifampicin Drug Toxicity

Hepatotoxicity associated with isoniazid and rifampicin is one of the major impediments in antituberculosis therapy. The present study explored the prophylactic and therapeutic efficacies of Spirulina maxima in isoniazid and rifampicin induced hepatic damage in a rat model. Hepatic damage induced in Wistar rats by isoniazid and rifampicin resulted in significant alterations in biomarkers of liver function, namely, bilirubin, aspartate transaminase, alanine transaminase, alkaline phosphatase, and oxidative stress markers such as superoxide dismutase, catalase, glutathione, and thiobarbituric acid reactive substances. Co-administration of Spirulina maxima along with antituberculosis drugs protected liver from hepatotoxicity due to isoniazid and rifampicin. Administration of Spirulina maxima consecutively for 2 weeks to hepatodamaged animals resulted in restoration of hepatic function as evident from normalization of serum markers of liver function. Thus, the present study revealed remarkable prophylactic and therapeutic potential of Spirulina maxima. Co-administration of Spirulina maxima and antituberculosis drugs is advantageous as it provides extra nutritional benefit.

The Effect of Garcin® in Preventing AntiTB-Induced Hepatitis in Newly Diagnosed Tuberculosis Patients

Adverse effects of antituberculosis agents such as hepatotoxicity may reduce treatment effectiveness, because they significantly contribute to nonadherence and eventually result in treatment failure, relapse or the emergence of drug resistance. Garlic is an ancient herbal substance, which its effectiveness on isoniazid and rifampicin-induced hepatic injury in animal models has been demonstrated (1). In the present study a randomized, double blind, placebo-controlled, parallel group clinical trial was designed to assess the effect(s) of garlic tablets (1000 mg daily) administered for two weeks orally. Fifty eight newly diagnosed, smear positive pulmonary tuberculosis patients, with age ranges between 18-65 years old, were randomly allocated into two groups. Each patient received either garlic or placebo tablets for the first two weeks of tuberculosis treatment. Of total 58 patients, 31 received garlic tablets while 27 received placebo. No significant difference was found between the two groups regarding age, sex, nationality, smoking, underlying diseases and opium usage. During 8 weeks of anti-TB (antituberculosis) treatment, 8 (13.0%) patients developed drug-induced hepatotoxicity (DIH). Of them, 6 (75%) occurred in the first two weeks of treatment. Fifty percent of the patients who developed DIH were in garlic group. Results indicated no significant difference between groups in developing DIH (p=1.000). We could not show a significant role in preventing DIH by 1000 mg daily garlic administration.

Protective effects of metallothionein on isoniazid and rifampicin-induced hepatotoxicity in mice

Isoniazid (INH) and Rifampicin (RFP) are widely used in the world for the treatment of tuberculosis, but the hepatotoxicity is a major concern during clinical therapy. Previous studies showed that these drugs induced oxidative stress in liver, and several antioxidants abated this effect. Metallothionein (MT), a member of cysteine-rich protein, has been proposed as a potent antioxidant. This study attempts to determine whether endogenous expression of MT protects against INH and RFP-induced hepatic oxidative stress in mice. Wild type (MT+/+) and MT-null (MT−/−) mice were treated intragastrically with INH (150 mg/kg), RFP (300 mg/kg), or the combination (150 mg/kg INH +300 mg/kg RFP) for 21 days. The results showed that MT−/− mice were more sensitive than MT+/+ mice to INH and RFP-induced hepatic injuries as evidenced by hepatic histopathological alterations, increased serum AST levels and liver index, and hepatic oxidative stress as evidenced by the increase of MDA production and the change of liver antioxidant status. Furthermore, INH increased the protein expression of hepatic CYP2E1 and INH/RFP (alone or in combination) decreased the expression of hepatic CYP1A2. These findings clearly demonstrate that basal MT provides protection against INH and RFP-induced toxicity in hepatocytes. The CYP2E1 and CYP1A2 were involved in the pathogenesis of INH and RFP-induced hepatotoxicity.

Hepatoprotective Effect of Cissus quadrangularis Stem Extract Against Rifampicin-induced Hepatotoxicity in Rats

The study was designed to investigate the hepatoprotective activity of methanol extract of Cissus quadrangularis against rifampicin-induced hepatotoxicity in rats.The coarse powder of the shade dried stem of Cissus quadrangularis was subjected to successive extraction in a Soxhlet apparatus using solvents petroleum ether (60-80°) and methanol. Liver damage was induced in Wistar rats by administering rifampicin (54 mg/kg, p.o.) once daily for 30 days. Methanol extract of Cissus quadrangularis (500 mg/kg, p.o) was administered 1 h prior to the administration of rifampicin (54 mg/kg, p.o.) once daily for 30 days. Silymarin (50 mg/kg p.o) used as reference drug. Elevated levels of aspartate transaminase, alanine transaminase, alkaline posphatase and bilirubin following rifampicin induction were significantly lowered due to pretreatment with methanol extract of Cissus quadrangularis. Rifampicin administration significantly increased lipid peroxidation and decreased antioxidant activities like reduced glutathione, superoxide dismutas and catalase. Pretreatment of rats with methanol extract of Cissus quadrangularis significantly decreased lipid peroxidation and increased the antioxidant activities. Histology of the liver section of the animals treated with the methanol extract of Cissus quadrangularis further confirms the hepatoprotective activity. The results of the present study indicated the hepatoprotective effect of methanol extract of Cissus quadrangularis which might be ascribable to its antioxidant property due to the presence of β-carotene.

Physical stability, antioxidative properties, and photoprotective effects of a functionalized formulation containing black garlic extract

When garlic is fermented, certain aspects of its bioactivity are changed. Black garlic is a type of fermented garlic used as a food ingredient in Asian cuisine. Black garlic's popularity has spread around the world as it has become a sought-after ingredient used in high-end cuisine. The formulations containing 10% black garlic extract or 10% normal garlic extract showed stable pH, color, precipitation, and organoleptic features, although these characteristics changed slightly. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the black garlic formulation were significantly (p<0.05) higher compared to those of the base formulation and normal garlic formulation. Mice treated with the black garlic formulation (119.63 μM/g) had significant (p<0.05) decreases in thiobarbituric acid reactive substance (TBARS) levels by lipid peroxidation compared to ultraviolet B (UVB)-control mice (142.37 μM/g). Moreover, significant (p<0.05) prevention of glutathione reduced form (GSH) depletion was observed in the black garlic formulation treated mice (vehicle: 3.46 mM/g vs. black garlic: 5.60mM/g). The formulation containing 10% black garlic extract retained physical stability and had high anti-radical efficiencies. Furthermore, it is possible to suggest that this formulation may be effective in protecting skin from UVB photodamage.

Hepatoprotective potential of ethanolic extract of Ziziphus oenoplia (L.) Mill roots against antitubercular drugs induced hepatotoxicity in experimental models

OBJECTIVE

To evaluate the hepatoprotective potential of ethanolic (50%) extract of Ziziphus oenoplia (L.) Mill (Z. oenoplia) root against isoniazid (INH) and rifampicin (RIF) induced liver damage in animal models.

METHODS

Five groups of six rats each were selected for the study. Ethanolic extract at a dose of 150 and 300 mg/kg as well as silymarin (100 mg/kg) were administered orally once daily for 21 d in INH + RIF treated groups. The serum levels of glutamic oxaloacetic transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase (SALP), and bilirubin were estimated along with activities of superoxide dismutase, catalase, glutathione S-transferase, glutathione peroxidase, and hepatic melondialdehyde formation. Histopathological analysis was carried out to assess injury to the liver.

RESULTS

The considerably elevated serum enzymatic activities of glutamic oxaloacetic transaminase, glutamate pyruvate transaminase, alkaline phosphatase and bilirubin due to INH + RIF treatment were restored towards normal in a dose dependent manner after the treatment with ethanolic extract of Z. oenoplia roots. Meanwhile, the decreased activities of superoxide dismutase, catalase, glutathione S-transferase and glutathione peroxidase were also restored towards normal dose dependently. In addition, ethanolic extract also significantly prevented the elevation of hepatic melondialdehyde formation in the liver of INH + RIF intoxicated rats in a dose dependent manner. The biochemical observations were supplemented with histopathological examination of rat liver sections.

CONCLUSIONS

The results of this study strongly indicate that ethanolic extract of Z. oenoplia has a potent hepatoprotective action against INH + RIF induced hepatic damage in rats.

Garlic in health and disease

The present article reviews the historical and popular uses of garlic, its antioxidant, haematological, antimicrobial, hepatoprotective and antineoplastic properties and its potential toxicity (from sulfoxide). Garlic has been suggested to affect several cardiovascular risk factors. It has also been shown that garlic and its organic allyl sulfur components are effective inhibitors of the cancer process. Since garlic and its constituents can suppress carcinogen formation, bioactivation and tumour proliferation, it is imperative that biomarkers be established to identify which individuals might benefit most. Garlic powder, aged garlic and garlic oil have demonstrated antiplatelet and anticoagulant effects by interfering with cyclo-oxygenase-mediated thromboxane synthesis. Garlic has also been found to have synergistic effects against Helicobacter pylori with a proton pump inhibitor. The active compound allicin may affect atherosclerosis not only by acting as an antioxidant, but also by other mechanisms, such as lipoprotein modification and inhibition of LDL uptake and degradation by macrophages. Freshly prepared garlic homogenate protects against isoniazid+rifampicin-induced liver injury in experimental animal models. Several mechanisms are likely to account for this protection.

Effect of garlic (Allium sativum) on nickel II or chromium VI induced alterations of glucose homeostasis and hepatic antioxidant status under sub-chronic exposure conditions

Garlic (Allium sativum) has a profound effect in reducing plasma glucose and increasing serum insulin in diabetic rats. We studied the effect of a garlic extract on nickel- or chromium-induced alteration of plasma glucose and hepatic glycogen levels and anti-oxidant status in rats. Adult male albino rats (n=36) divided into six groups of six animals each were treated as follows: Group I, untreated controls; Group II, fresh aqueous homogenate of garlic; Group III, nickel sulfate; Group IV, nickel sulfate + garlic; Group V, potassium dichromate; Group VI, potassium dichromate + garlic. In Groups IV and VI, the simultaneous administration of garlic abrogated a significant nickel- or chromium-induced increase in plasma glucose and decrease in liver glycogen. Nickel and chromium alone also increased lipid peroxide (LPO) and decreased glutathione levels, as well as the activity of superoxide dismutase (SOD), catalase, and glutathione peroxidase. Simultaneous garlic administration significantly reduced the LPO level and remarkably improved SOD activity. Hence, we postulate that the administration of garlic can prevent nickel II- or chromium VI-induced alterations in blood glucose homeostasis while exerting a hepatoprotective effect on glycogen levels and antioxidant status in male albino rats.

Silymarin protects liver against toxic effects of anti-tuberculosis drugs in experimental animals

BACKGROUND

The first line anti-tuberculosis drugs isoniazid (INH), rifampicin (RIF) and pyrazinamide (PZA) continues to be the effective drugs in the treatment of tuberculosis, however, the use of these drugs is associated with toxic reactions in tissues, particularly in the liver, leading to hepatitis. Silymarin, a standard plant extract with strong antioxidant activity obtained from S. marianum, is known to be an effective agent for liver protection and liver regeneration. The aim of this study was to investigate the protective actions of silymarin against hepatotoxicity caused by different combinations of anti-tuberculosis drugs.

METHODS

Male Wistar albino rats weighing 250-300 g were used to form 6 study groups, each group consisting of 10 rats. Animals were treated with intra-peritoneal injection of isoniazid (50 mg/kg) and rifampicin (100 mg/kg); and intra-gastric administration of pyrazinamid (350 mg/kg) and silymarin (200 mg/kg). Hepatotoxicity was induced by a combination of drugs with INH+RIF and INH+RIF+PZA. Hepatoprotective effect of silymarin was investigated by co-administration of silymarin together with the drugs. Serum biochemical tests for liver functions and histopathological examination of livers were carried out to demonstrate the protection of liver against anti-tuberculosis drugs by silymarin.

RESULTS

Treatment of rats with INH+RIF or INH+RIF+PZA induced hepatotoxicity as evidenced by biochemical measurements: serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities and the levels of total bilirubin were elevated, and the levels of albumin and total protein were decreased in drugs-treated animals. Histopathological changes were also observed in livers of animals that received drugs. Simultaneous administration of silymarin significantly decreased the biochemical and histological changes induced by the drugs.

CONCLUSION

The active components of silymarin had protective effects against hepatotoxic actions of drugs used in the chemotherapy of tuberculosis in animal models. Since no significant toxicity of silymarin is reported in human studies, this plant extract can be used as a dietary supplement by patients taking anti-tuberculosis medications.

Protective effects of garlic powder against potassium dichromate-induced oxidative stress and nephrotoxicity

Potassium dichromate (K(2)Cr(2)O(7))-induced nephrotoxicity is associated with oxidative stress. In the present work the effect of garlic powder, a recognized antioxidant, on K(2)Cr(2)O(7)-induced nephrotoxicity and oxidative stress was studied. Rats were fed a 2% garlic powder diet for 1 month. A single injection of K(2)Cr(2)O(7) (15 mg/kg) to rats induced tubule interstitial damage and an increase in the following markers of renal injury 2 days later: blood urea nitrogen (4.6-fold), serum creatinine (9.7-fold), proteinuria (35.9-fold), urinary excretion of N-acetyl-beta-d-glucosaminidase (12.9-fold) and glutathione-S-transferase (2.3-fold) and a decrease of 65% in serum glutathione peroxidase activity. In addition, K(2)Cr(2)O(7) injection increased the following nitrosative and oxidative stress markers in kidney: 3-nitrotyrosine (1.9-fold), 4-hydroxy-2-nonenal (2.1-fold), malondialdehyde (1.8-fold) and protein carbonyl content (1.7-fold). It was found that garlic powder feeding was able to prevent by 44-71% the alterations in the markers of renal injury studied, by 55% the histological damage, and by 47-100% the increase in markers of oxidative and nitrosative stress. It is concluded that the ability of garlic powder to ameliorate K(2)Cr(2)O(7)-induced renal injury is associated with its antioxidant properties. Our data support the use of garlic powder as a renoprotective agent.

Effects of four Indian medicinal herbs on Isoniazid-, Rifampicin- and Pyrazinamide-induced hepatic injury and immunosuppression in guinea pigs

AIM: To evaluate and compare the hepatoprotective and immunomodulatory effects of Curcuma longa (CL), Ocimum sanctum (OS), Tinospora cordifolia (TC) and Zizyphus mauritiana (ZM) on liver injury and immunosuppression induced by Isoniazid (INH), Rifampicin (RIF) and Pyrazinamide (PZA).

METHODS: Duncan Hartley guinea pigs, weighing 700-1050 g, were treated orally with 50 mg/kg of INH, 100 mg/kg of RIF and 300 mg/Kg of PZA for 21-d. 200 mg/kg (bw) of each herb crude extract was administered to the herb control group and 2-h previous to INH + RIF + PZA (AKT) doses to the Herb + AKT groups. Serum alanine aminotransferase (ALT), aspertate aminotransferase (AST) bilirubin and Alkaline Phosphatase (ALP) were assessed on d 0 and 21 in all the groups. Phagocytic % (P%), Phagocytic Index (PI) and Chemotactic Index (CI) were also measured as immunologic parameters. Histological analysis was carried out to assess injury to the liver.

RESULTS: The AKT treated control group showed hepatotoxicity as judged by elevated serum AST 5-fold, AST/ALT ratio 4-fold, ALP 2-fold and hepatological changes, such as focal necrosis, portal triaditis and steatosis. Immune function was suppressed as judged by decreased P% (51.67 ± 1.68 vs 40.61 ± 1.28, P < 0.01), PI (2.0725 ± 0.05 vs 0.61 ± 0.05, P < 0.001) and CI (1.8525 ± 0.04 vs 0.695 ± 0.07, P < 0.001). All four herb treated groups showed normal liver histology, enzyme levels and increased P%, while PI and CI were enhanced in the TC and ZM treated groups, respectively. CL + AKT, TC + AKT and ZM + AKT showed nearly normal histology with minimal inflammation and microvesicular steatosis, while OS + AKT showed partial protection. Hepatotoxicity was prevented by restricting the rise of AST by 2-fold in CL + AKT and TC + AKT groups and by 3-fold in OS + AKT and ZM + AKT groups, AST/ALT by 2-fold and ALP to normal levels in all four groups. All four herb + AKT groups showed normal to enhanced neutrophil function.

CONCLUSION: All four herbs showed hepatoprotective potential and prevented immunosuppression. CL and TC showed the highest hepatoprotective activity, while TC and ZM showed strong immunostimulatory activity.

Drug-induced liver disease in 2006

PURPOSE OF REVIEW

To identify the key publications of 2006 dealing with drug-induced liver injury.

RECENT FINDINGS

When given in therapeutic doses over 14 days, acetaminophen produced significant asymptomatic elevations in alanine aminotransferase among healthy volunteers, suggesting that subclinical injury may be more common than previously thought. Acute liver failure in children was shown to differ in several important respects from that seen in adults, notably a much lower incidence of acetaminophen toxicity with nearly half of all cases being indeterminate in origin. The first cases of hepatotoxicity with telithromycin, a new class of ketolide antibiotic, were described along with reports suggesting liver injury from ezetimibe among other agents. The potential for chronic injury to develop after acute drug-induced liver injury was analyzed in a large Swedish database; 5-6% of cases were judged to become chronic, with drugs causing cholestatic injury predominating. Among well described hepatotoxins, new reports appeared with highly active antiretroviral therapy agents, herbal therapies and several antibiotics. Finally, the safe use of pravastatin and pioglitazone was demonstrated in patients with chronic liver disease in controlled clinical trials.

SUMMARY

Drug-induced liver injury remains an important concern for many existing drugs as well as for agents in development.

Increased anti-oxidative potency of garlic by spontaneous short-term fermentation

Fundamental anti-oxidative properties of 80% ethanol extract from garlic fermented for the relatively short period of time (40 days at 60-70 degrees C, 85-95% relative humidity) were examined. Superoxide dismutase (SOD)-like activity, scavenging activity against hydrogen peroxide and the polyphenol content of the garlic extract were increased 13-folds, more than 10-folds, and 7-folds, respectively, as compared with those of the control garlic extract. The results indicate that relatively short-term spontaneous fermentation potentiates anti-oxidative properties of garlic in fresh form, which is, at least in part, attributable to the increased level of polyphenols. Since superoxide is the primary upstream radical of the chain reaction with reactive oxygen species and hydrogen peroxide is generated from the scavenging reaction by SOD, the fermented- garlic is suggested to possess desirable anti-oxidative properties.

Increased level of tetrahydro-beta-carboline derivatives in short-term fermented garlic

In our previous study [1], we found that relatively short-term spontaneous fermentation (40 days at 60-70 degrees C, 85-95% relative humidity) potentiates anti-oxidative properties of garlic, in which scavenging activity against hydrogen peroxide was included. Since tetrahydro-beta-carboline derivatives (THbetaCs) that possess hydrogen peroxide scavenging activity have recently been identified in aged garlic extract, THbetaCs were quantitatively analyzed with liquid chromatography-mass spectrometry (LC-MS). (1R, 3S)-1-Methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCC) and (1S, 3S)-MTCC were found in the fermented garlic extract whereas only trace levels of MTCCs were detected in the row garlic extract. Therefore, it is suggested that relatively short-term fermentation potentiates scavenging activity of garlic against hydrogen peroxide by forming THbetaCs, especially MTCCs.