Thioacetamide-induced Toxicity Research Articles

Chlorogenic acid alleviates thioacetamide-induced toxicity and promotes liver development in zebrafish (Danio rerio) through the Wnt signaling pathway.

Chlorogenic acid (CGA) is a phenylpropanoid compound that is well known to improve the antioxidant capacity and other biological activities. However, the roles of CGA in the liver development of organisms are unclear. In the present study, we aimed to investigate the function of CGA in the hepatic development in thioacetamide (TAA)-induced zebrafish embryos. We found that CGA exerted certain beneficial effects on zebrafish larvae from TAA-exposed zebrafish embryos, such as increasing the liver size, body length, heart rate, acetylcholinesterase activity, and motor ability. In addition, CGA displayed an antioxidant effect on TAA-induced zebrafish embryos by enhancing the activities of superoxide dismutase (SOD), catalase (CAT), and glucose-6-phosphate dehydrogenase (G6PDH), and decreasing of the contents of malondialdehyde (MDA), reactive oxygen species (ROS), and nitric oxide (NO). The results of western blotting analysis showed that CGA inhibited cell apoptosis by increasing the levels of Bcl2 apoptosis regulator and decreasing the levels of Bcl2 associated X (Bax), apoptosis regulator and tumor protein P53. Moreover, CGA promoted cell proliferation in TAA-induced zebrafish larvae, as detected using proliferating cell nuclear antigen fluorescence immunostaining. In addition, CGA inhibited the expression of Wnt signaling pathway genes Dkk1 (encoding Dickkopf Wnt signaling pathway inhibitors), and promoted the expression of Lef1 (encoding lymphoid enhancer binding factor 1) and Wnt2bb (encoding wingless-type MMTV integration site family, member 2Bb). When the Wnt signal inhibitor IWR-1 was added, there was no significant change in liver development in the IWR-1+TAA group compared with the IWR-1+TAA+CGA group (p <0.05), which suggested that CGA regulates liver development via Wnt signaling pathway. Overall, our results suggested that CGA might alleviate TAA-induced toxicity in zebrafish and promote liver development through the Wnt signaling pathway, which provides a basis for the therapeutic effect of CGA on liver dysplasia.

Protective effects and molecular mechanisms of baicalein on thioacetamide-induced toxicity in zebrafish larvae

Baicalein is a flavonoid that is widely found in plants. Studies have shown that baicalein has anti-inflammatory, anti-cancer, and liver-protective effects. However, the effects of baicalein on TAA-induced toxicity and the underlying molecular mechanisms in zebrafish larvae are still unknown. Here, we investigated the effects of baicalein on liver development and its anti-inflammatory effects in zebrafish larvae. The results showed that baicalein has significant anti-embryonic developmental toxicity and significant antioxidant and anti-inflammatory capabilities in TAA-induced zebrafish larvae and promotes liver development and cell proliferation, reduces the expression of apoptotic proteins, and induces the expression of anti-apoptotic proteins. At the molecular level of TAA-treated zebrafish larvae, there was a decrease in the relative expression levels of mRNAs of three subfamilies, P38, ERK1, and ERK2, of the MAPK-signaling pathway and of the products of peroxisome proliferator-activated receptor (PPAR)α. Compared with TAA-treated zebrafish larvae, zebrafish larvae treated with baicalein showed an increase in the relative expression levels of P38, ERK1, and ERK2 mRNAs and the downstream products of PPARα. When MAPK signal inhibitor (SB203580) was added, it was found that liver development was inhibited and baicalin had no protective effect on TAA induced hepatotoxicity in zebrafish larvae. The results showed baicalein can protect the zebrafish larvae against toxicity induced by TAA through MAPK signal pathway. Several molecular mechanisms discovered in this study may help in the development of new drugs.

Amelioration of hepatic function, oxidative stress, and histopathologic damages by Cassia fistula L. fraction in thioacetamide-induced liver toxicity.

Cassia fistula L. (Caesalpinioideae) is a highly admirable medicinal plant and is traditionally recommended for the treatment of rheumatism, liver disorders, jaundice, and other inflammatory diseases. This study was designed to investigate the hepatoprotective properties of ethyl acetate fraction from C. fistula leaves in an animal model. Treatment with thioacetamide significantly elevated the level of serum glutamic-oxaloacetic transaminase (1.75-fold), alkaline phosphatase (4.07-fold), and total bilirubin (2.29-fold) as compared to the control. It was found that pretreatment of fraction followed by consecutive 2 days thioacetamide reduced the conversion of thioacetamide carcinogen to its reactive metabolites by phase I enzymes and increased the level of detoxification phase II along with antioxidative enzymes. The histopathological studies revealed the hepatoprotective nature of the fraction in restoring the normal architecture of thioacetamide-intoxicated damaged liver. The fraction showed downregulation in the expression level of p-PI3K, p-Akt, and p-mTOR pointing towards its chemopreventive potential. The HPLC analysis of the fraction had shown the dominance of three phenolic compounds namely, catechin, epicatechin, and chlorogenic acid. The above studies comprising histopathological, immunohistochemical, and hepatic enzymes are strong indicative of the potential protective ability of ethyl acetate fraction phytoconstituents against thioacetamide-induced toxicity. Graphical abstract.

Allium porrum and Bauhinia Variegata Mitigate Acute Liver Failure and Nephrotoxicity Induced by Thioacetamide in Male Rats.

The present work has been designed to investigate the hepatoprotective and renoprotective efficiency of alcoholic extract of Allium porrum and Bauhinia variegata leaves in thioacetamide-induced toxicity in adult Wistar rats. Allium porrum leaf extract, Bauhinia variegata leaf extract and their combinations were orally administered for 14days then TAA (300mg/kg) i.p. was injected once and the rats were sacrificed 2days later. Plasma AST, ALT, GGT, total bilirubin, creatinine, urea, uric acid, triglyceride, cholesterol, HDL and LDL were measured. Liver MDA, GSH, CAT, SOD and TNF-α were evaluated. Histological examination was performed. The rats treated with TAA showed a significant increase in AST, ALT, GGT, total bilirubin, creatinine, urea, uric acid, total, triglyceride, cholesterol and HDL while it led to a significant decrease in protein and HDL. The treatment of rats with TAA resulted in a significant decrease of the hepatic GSH, SOD and CAT and a significant elevation of MDA and TNF-α. Allium porrum and Bauhinia variegata extracts alleviated the toxic effects of TAA on the liver and the kidney. In conclusion, treatment with Allium porrum and Bauhinia variegata extracts and their combination reduced deleterious effects of TAA on liver through antioxidant and anti-inflammatory properties.

Nephroprotective effect of cilostazol and verapamil against thioacetamide-induced toxicity in rats may involve Nrf2/HO-1/NQO-1 signaling pathway

Cilostazol and verapamil are widely used cardiovascular drugs, explored a beneficial effect on different organs-induced toxicities. We investigated whether the Nrf2 (nuclear erythroid factor 2) and its downstream pathway are involved in the protective role of these drugs against TAA-induced renal damage. Renal biomarkers (creatinine and urea) and histopathology were observed. Antioxidant and oxidant indicators; superoxide dismutase (SOD), reduced glutathione (GSH), malondialdehyde (MDA) and total nitrite (NO) were also measured. Antioxidant markers like; Nrf2/hemoxegenase-1 (HO-1) and NADPH quinone oxidoreductase-1 (NQO-1) expressions were determined by ELISA and immunohistochemistry. Cilostazol and verapamil pretreatment improved serum creatinine and urea elevation. Examined drugs also have an ameliorative effect on TAA-induced elevation in MDA and NO activities and antioxidant enzymes; SOD and GSH. Additionally, the pretreated drugs significantly up-regulated Nrf2/HO-1/NQO-1 expression levels. In conclusion, cilostazol and verapamil exerted their protective effects partially via a Nrf2/HO-1/NQO-1 activation pathway with anti-oxidant roles.

Silymarin Protects Mouse Liver and Kidney from Thioacetamide Induced Toxicity by Scavenging Reactive Oxygen Species and Activating PI3K-Akt Pathway.

Silymarin (SMN) has been shown to possess a wide range of biological and pharmacological effects. Besides, SMN has antioxidant and free radical scavenging activities. Thioacetamide (TAA) is a well-documented liver toxin that requires oxidative bioactivation to elicit its hepatotoxic effect which ultimately modifies amine-lipids and proteins. Our study has been designed in a TAA exposed mouse model to investigate whether SMN could protect TAA-induced oxidative stress mediated hepatic and renal damage. Results suggest that TAA generated reactive oxygen species (ROS), caused oxidative stress and induced apoptosis in the liver and kidney cells via JNK as well as PKC and MAPKs signaling. All these detrimental effects of TAA could, however, be suppressed by SMN which not only scavenged ROS but also induced PI3K-Akt cell survival pathway in the liver and prevented apoptotic pathways in both the organs. Histological studies, collagen staining and DNA fragmentation analysis also supported our results. Combining, we say that SMN possess beneficial role against TAA mediated hepatic and renal pathophysiology.

Andrographis paniculata leaf extract prevents thioacetamide-induced liver cirrhosis in rats.

This study investigated the hepatoprotective effects of ethanolic Andrographis paniculata leaf extract (ELAP) on thioacetamide-induced hepatotoxicity in rats. An acute toxicity study proved that ELAP is not toxic in rats. To examine the effects of ELAP in vivo, male Sprague Dawley rats were given intraperitoneal injections of vehicle 10% Tween-20, 5 mL/kg (normal control) or 200 mg/kg TAA thioacetamide (to induce liver cirrhosis) three times per week. Three additional groups were treated with thioacetamide plus daily oral silymarin (50 mg/kg) or ELAP (250 or 500 mg/kg). Liver injury was assessed using biochemical tests, macroscopic and microscopic tissue analysis, histopathology, and immunohistochemistry. In addition, HepG2 and WRL-68 cells were treated in vitro with ELAP fractions to test cytotoxicity. Rats treated with ELAP exhibited significantly lower liver/body weight ratios and smoother, more normal liver surfaces compared with the cirrhosis group. Histopathology using Hematoxylin and Eosin along with Masson’s Trichrome stain showed minimal disruption of hepatic cellular structure, minor fibrotic septa, a low degree of lymphocyte infiltration, and minimal collagen deposition after ELAP treatment. Immunohistochemistry indicated that ELAP induced down regulation of proliferating cell nuclear antigen. Also, hepatic antioxidant enzymes and oxidative stress parameters in ELAP-treated rats were comparable to silymarin-treated rats. ELAP administration reduced levels of altered serum liver biomarkers. ELAP fractions were non-cytotoxic to WRL-68 cells, but possessed anti-proliferative activity on HepG2 cells, which was confirmed by a significant elevation of lactate dehydrogenase, reactive oxygen species, cell membrane permeability, cytochrome c, and caspase-8,-9, and, -3/7 activity in HepG2 cells. A reduction of mitochondrial membrane potential was also detected in ELAP-treated HepG2 cells. The hepatoprotective effect of 500 mg/kg of ELAP is proposed to result from the reduction of thioacetamide-induced toxicity, normalizing reactive oxygen species levels, inhibiting cellular proliferation, and inducing apoptosis in HepG2 cells.

Protective Effects of Diallyl Sulfide against Thioacetamide-Induced Toxicity: A Possible Role of Cytochrome P450 2E1.

Effects of diallyl sulfide (DAS) on thioacetamide-induced hepatotoxicity and immunotoxicity were investigated. When male Sprague-Dawley rats were treated orally with 100, 200 and 400 mg/kg of DAS in corn oil for three consecutive days, the activity of cytochrome P450 (CYP) 2E1-selective p-nitrophenol hydroxylase was dose-dependently suppressed. In addition, the activities of CYP 2B-selective benzyloxyresorufin O-debenzylase and pentoxyresorufin O-depentylase were significantly induced by the treatment with DAS. Western immunoblotting analyses also indicated the suppression of CYP 2E1 protein and/or the induction of CYP 2B protein by DAS. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 400 mg/kg of DAS for 3 days, followed by a single intraperitoneal treatment with 100 and 200 mg/kg of thioacetamide in saline for 24 hr. The activities of serum alanine aminotransferase and aspartate aminotransferase significantly elevated by thioacetamide were protected in DAS-pretreated animals. Likewise, the suppressed antibody response to sheep erythrocytes by thioacetamide was protected by DAS pretreatment in female BALB/c mice. Taken together, our present results indicated that thioacetamide might be activated to its toxic metabolite(s) by CYP 2E1, not by CYP 2B, in rats and mice.

Preventive and curative role of a 43kD protein from the leaves of the herb L on thioacetamide-induced hepatotoxicity in vivo

An approximately 43kD protein has been isolated and purified from the herb Cajanus indicus L and believed to be the most active principle for its hepatoprotective action. In this study, experiments have been performed to evaluate the effectiveness of that protein for the preventive and curative action against thioacetamide-induced toxicity in vivo using a murine model. Mice were treated with the protein intraperitoneally at a dose of 2mg/kg body weight for 2 and 6 days before and separately 1-5 days after thioacetamide administration to evaluate its preventive and curative role, respectively. Thioacetamide was administered once at a dose of 150mg/kg body weight and after 48h of its application, the animals were sacrificed. Levels of various markers related to physiological and pathological conditions of the liver, e.g., glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP), etc. were determined in the murine sera under different experimental conditions. In addition, antioxidant enzymes glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) as well as thiobarbituric acid reactive substances (TBARS), were measured from the liver homogenates. The antioxidant property of the protein was compared with the potent antioxidant, vitamin E (used as a positive control). The active principle effectively reduced the elevated GPT and ALP levels in serum and lipid peroxidation in the liver tissue. The reduced levels of SOD, CAT and GST by thioacetamide were again brought back to almost normal levels upon pre- and post-treatment with the protein. Histopathological changes in the liver of TAA control and protein-treated groups also prove that the protein possesses hepatoprotective activity. The protein acts dose-dependently and maximum hepatoprotectivity was obtained when administered at a dose of 2mg/kg body weight. Data suggest that the active principle plays an important preventive and curative role against thioacetamide-induced hepatotoxicity.

Protective Effect of Phyllanthus fraternus against Thioacetamide-Induced Mitochondrial Dysfunction.

The effect of administration of thioacetamide on rat liver mitochondrial functions and the protective effect of an aqueous extract of Phyllanthus fraternus against thioacetamide-induced damage were studied. When rats were treated with thioacetamide, the rate of mitochondrial respiration was decreased significantly with both NAD+ linked and FAD linked substrates, and the respiratory control ratio, an index of membrane integrity and the P/O ratio, a measure of phosphorylation efficiency, decreased significantly. Also, there was a significant decrease in the activities of NADH dehydrogenase, succinate cytochrome c reductase, and cytochrome oxidase; whereas succinate dehydrogenase was not affected. A significant decrease was seen in membrane potential and in the level of mitochondrial ATP. There was a significant decrease in the levels of phosphatidylcholine, phosphatidylethanolamine, and cardiolipin by thioacetamide treatment. The lipid peroxide level increased significantly in thioacetamide-treated rats. Administration of P. fraternus prior to thioacetamide treatment relieved the inhibition of all the parameters studied, and brought down the lipid peroxide levels significantly in liver homogenates and mitochondria. This study shows that P. fraternus protects against thioacetamide-induced toxicity by its ability to suppress the elevated lipid peroxide levels in the mitochondrial membrane.