Involvement of Nrf2, JAK and COX pathways in acetaminophen-induced nephropathy: Role of some antioxidants.

Objectives: Acetaminophen (APAP)-induced nephrotoxicity is detrimental consequence for which there has not been a standardized therapeutic regimen. Although, N-acetylcysteine (NAC) is a well-known antidote used in APAP-induced hepatotoxicity, its benefit in nephrotoxicity caused by APAP is almost lacking. This study aimed to compare the possible protective effect of thymoquinone (TQ), curcumin (CR), and α-lipoic acid (α-LA), either in solo or in combination regimens with that of NAC against APAP-induced renal injury. Design and method: Rats were divided into nine groups; control group, APAP intoxicated group (1000 mg/kg; orally), and the remaining seven groups received, in addition to APAP, oral doses of NAC, TQ, CR, α-LA, CR plus TQ, TQ plus α-LA, or CR plus α-LA. The first dose of the aforementioned antioxidants was given 24 h before APAP, and then the second dose was given 2 h after APAP, whereas the last dose was given 10 h after administration of APAP. Results: Treatment with APAP elevated kidney markers like serum uric acid, urea, and creatinine. In addition, it increased the serum level of tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1ß) and thiobarbituric acid reactive species (TBARS). Also, the protein expression of renal janus kinase (JAK) and cyclooxygenase (COX)-2 were all upregulated by APAP. In contrast, the expression of Nrf2 and the renal levels of superoxide dismutase and glutathione were downregulated. Treatment with the indicated natural antioxidants resulted in amelioration of the aberrated parameters through exhibiting anti-inflammatory, antioxidant and free radical-scavenging effects with a variable degree. Conclusion: The combined administration of CR and TQ exerted the most potent protection against APAP-induced nephrotoxicity through its anti-inflammatory and free radical-scavenging effects (antioxidant) which were comparable to that of NAC-treatment.

Nano-Resveratrol: A Promising Candidate for the Treatment of Renal Toxicity Induced by Doxorubicin in Rats Through Modulation of Beclin-1 and mTOR.

Background: Although doxorubicin (DXR) is one of the most used anticancer drugs, it can cause life-threatening renal damage. There has been no effective treatment for DXR-induced renal damage until now. Aim: This work aims at examining the potential impact of nano-resveratrol (N-Resv), native resveratrol (Resv), and their combination with carvedilol (Card) against DXR-induced renal toxicity in rats and to investigate the mechanisms through which these antioxidants act to ameliorate DXR nephrotoxicity. Method: DXR was administered to rats (2 mg/kg, i.p.) twice weekly over 5 weeks. The antioxidants in question were taken 1 week before the DXR dose for 6 weeks. Results: DXR exhibited an elevation in serum urea, creatinine, renal lipid peroxide levels, endoglin expression, kidney injury molecule-1 (KIM-1), and beclin-1. On the other hand, renal podocin and mTOR expression and GSH levels were declined. In addition, DNA fragmentation was markedly increased in the DXR-administered group. Treatment with either Resv or N-Resv alone or in combination with Card ameliorated the previously measured parameters. Conclusion: N-Resv showed superior effectiveness relative to Resv in most of the measured parameters. Histopathological examination revealed amelioration of renal structural and cellular changes after DXR by Card and N-Resv, thus validating the previous biochemical and molecular results.

Chitosan nanoparticles as a promising candidate for liver injury induced by 2-nitropropane: Implications of P53, iNOS, VEGF, PCNA, and CD68 pathways.

The current article was designed to assess the role of chitosan nanoparticles (CNPs) in the management of hepatic injury induced by the hepatocarcinogen 2-nitropropane (2-NP). Rats were divided into three groups. The first group served as a control, the second group was injected with 2-NP, while the third group was treated with CNPs 1 h before 2-NP injection every other day for 4 weeks. The 2-NP injection upregulated serum AST and ALT activities, as well as hepatic TNF- α, IL-6, and MDA levels and the expression of vascular endothelial growth factor (VEGF) and caspase-3, whereas GSH contents and SOD activity were decreased. Immunohistochemistry investigations revealed that the hepatic protein expression of collagen I, inducible nitric oxide synthetase, proliferating cell nuclear antigen, cluster of differentiation, and p53 were upregulated. hematoxylin and eosin (H&E) and Masson's trichrome stains supported the previous parameters, and CNPs ameliorated most of the previous biochemical parameters. CNPs achieved promising results in the limitation of 2-NP hepatotoxicity.

Manipulation of Quercetin and Melatonin in the Down-Regulation of HIF-1α, HSP-70 and VEGF Pathways in Rat's Kidneys Induced by Hypoxic Stress.

Hypoxia may lead to inflammatory responses by numerous signaling pathways. This investigation intended to inspect the defensive role of Quercetin (Quer) and/ or Melatonin (Mel) against reno toxicity induced by Sodium nitrite (Sod ntr). Sod ntr injection significantly decreased blood hemoglobin concentration (Hb) with a concurrent increase in serum tumor necrosis factor- α, interleukin-6, C-reactive protein, creatinine, and urea levels. Over protein-expression of vascular endothelial growth factor and heat shock, protein-70 and mRNA of HIF-1α were also observed. Pretreatment of the Sod ntr- injected rats with the aforementioned antioxidants; either alone or together significantly improved such parameters. Histopathological examination reinforced the previous results. It was concluded that the combined administration of Quer and Mel may be useful as a potential therapy against renal injury induced by Sod ntr. HIF-1α and HSP-70 are implicated in the induction of hypoxia and its treatment.

Role of α-tocopherol and Lactobacillus plantarum in the alleviation of mercuric chloride-induced testicular atrophy in rat's model: Implication of molecular mechanisms.

The present work was aimed to evaluate the protective effects of alpha-tocopherol (α-toco) and/or Lactobacillus plantarum (LCB) against testicular atrophy induced by mercuric chloride (MCH). Rats were injected with 5 mg/kg MCH for 5 days consecutively, then treated with 100 mg/kg α-toco and 6 × 1010 CFU 1.8701/kg LCB alone or together for 3 weeks. The MCH elevated serum TNF-α, IL- 6, caspase-3, and testicular malondialdehyde. However, serum testosterone, dehydroepiandrosterone, testicular messenger RNA of a steroidogenic acute regulatory protein, 17-ß-hydroxysteroid dehydrogenase, 3ß-hydroxysteroid dehydrogenase, glutathione level, and superoxide dismutase activity were decreased. Protein expression of Nrf2 was downregulated whereas that of Bax and DNA fragmentation was upregulated in the testicular tissues. Treatment with α-toco and LCB ameliorated the deviated biochemical parameters and improved tissue injury. It was concluded that the combination of LCB and α-toco achieved promising results in the amelioration of MCH-induced testicular atrophy. Nrf2, Bax expressions, and DNA fragmentation are involved in the testicular atrophy induced by MCH.

Role of some natural anti-oxidants in the down regulation of Kim, VCAM1, Cystatin C protein expression in lead acetate-induced acute kidney injury.

BACKGROUND: Lead is a dangerous systemic toxicant and can provoke life-threatening renal injury. The plan of this study was to evaluate the potential impact of curcumin (CRMN) and L-ascorbic acid (L-ascb) alone or together to counteract lead acetate (Pb-acetate)-induced renal damage in rats and to find out the underlying mechanisms of action of these nutraceuticals. METHODS: Pb-acetate (100 mg/kg/day, i.p.) was injected in male rats along with L-ascb (250 mg/kg/day) and/or CRMN (200 mg/kg/day) orally for 7 days. RESULTS: Pb-acetate administration increased serum urea, creatinine and uric acid. Renal tissue showed a marked depletion in reduced glutathione level and superoxide dismutase activity and elevation in nitric oxide and malondialdehyde levels. Serum C-reactive protein and IL-1ß levels were elevated. Up-regulation of the expression of kidney injury molecule, vascular adhesion molecule-1 and Cystatin C were noticed after Pb-acetate administration. DNA fragmentation was also increased in renal tissues. Histopathological examination revealed a destructed partial layer of Bowman's capsule, proximal and distal convoluted tubules. Treatment with the aforementioned antioxidants ameliorated most of the altered measured biomarker levels. CONCLUSION: Interestingly, the combination of L-ascb and CRMN showed the superlative protective effect against Pb-acetate-induced nephrotoxicity.

Prophylactic administration of carnosine and melatonin abates the incidence of apoptosis, inflammation, and DNA damage induced by titanium dioxide nanoparticles in rat livers.

Although titanium dioxide nanoparticles (TDO-ns) are extensively used in the food, medicine, and cosmetic industries, discussions about the possible hazards of nanomaterials are just beginning to emerge. This study aimed to detect the inflammatory stress, oxidative stress, and apoptotic cell death induced in the livers of rats exposed to TDO-ns (600 mg/kg, particle size ≤ 100 nm). Furthermore, the modulation of these toxic effects by two potent naturally occurring antioxidants, carnosine (Carno) or melatonin (Melato), was evaluated. The co-administration of carnosine or melatonin to rats intoxicated with TDO-ns significantly attenuated the increases in serum tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), immunoglobulin G (IgG), vascular endothelial growth factor (VEGF), nitric oxide (NO), and alanine aminotransferase (ALT) levels. The two agents markedly ameliorated hepatic DNA damage and the alterations in hepatic malondialdehyde (MDA), glutathione (GSH), cytochrome P450, caspase-3, total phospholipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, and triglyceride (TG) levels. These results support the use of Carno or Melato as prophylactic agents against TDO-ns-induced liver damage.

Arctium lappa Root Extract Prevents Lead-Induced Liver Injury by Attenuating Oxidative Stress and Inflammation, and Activating Akt/GSK-3ß Signaling.

Arctium lappa L (A. lappa) is a popular medicinal plant with promising hepatoprotective activity. This study investigated the protective effect of A. lappa root extract (ALRE) on lead (Pb) hepatotoxicity, pointing to its ability to modulate oxidative stress, inflammation, and protein kinase B/Akt/glycogen synthase kinase (GSK)-3ß signaling. Rats received 50 mg/kg lead acetate (Pb(Ac)2) and 200 mg/kg ALRE or vitamin C (Vit. C) for 7 days, and blood and liver samples were collected. Pb(Ac)2 provoked hepatotoxicity manifested by elevated serum transaminases and lactate dehydrogenase, and decreased total protein. Histopathological alterations, including distorted lobular hepatic architecture, microsteatotic changes, congestion, and massive necrosis were observed in Pb(II)-induced rats. ALRE ameliorated liver function and prevented all histological alterations. Pb(II) increased hepatic lipid peroxidation (LPO), nitric oxide (NO), caspase-3, and DNA fragmentation, and serum C-reactive protein, tumor necrosis factor-α, and interleukin-1ß. Cellular antioxidants, and Akt and GSK-3ß phosphorylation levels were decreased in the liver of Pb(II)-induced rats. ALRE ameliorated LPO, NO, caspase-3, DNA fragmentation and inflammatory mediators, and boosted antioxidant defenses in Pb(II)-induced rats. In addition, ALRE activated Akt and inhibited GSK-3ß in the liver of Pb(II)-induced rats. In conclusion, ALRE inhibits liver injury in Pb(II)-intoxicated rats by attenuating oxidative injury and inflammation, and activation of Akt/GSK-3ß signaling pathway.

Mitigation of acetamiprid - induced renotoxicity by natural antioxidants via the regulation of ICAM, NF-kB and TLR 4 pathways.

BACKGROUND: Acetamiprid (ACMP) is a member of the neonicotinoid group of insecticides. It is extensively used worldwide. The misuse of ACMP creates danger hazards to human and animal. METHODS: ACMP induced renal damage evidenced by an increase in kidney injury biomarkers. So the goal of this work is to clarify the reno protective effect of Quercetin (Qrctn) and/or Nano-glutathione (N-Gluta) solely or in combination to counterbalance the danger effect of ACMP. All treatments with the previous agents were coadministered orally with ACMP for one month. RESULTS: ACMP ingestion caused a significant rise in serum creatinin, urea, and uric acid, TNF α along with renal cystatin C, lipid peroxidation and nitric oxide with the concomitant decline in the levels of reduced glutathione and IL-10 levels. Protein expression of ICAM was upregulated as well as mRNA expression of NF-κB while mRNA expression of Nrf2 was down-regulated. Immune histochemistry of TLR 4 revealed strong immune reaction. The administration of Qrctn or N-Gluta either individually or together modulated all the preceding aforementioned parameters. CONCLUSION: Fascinatingly Qrctn and N-Gluta combination was the most powerful regimen to frustrate ACMP reno-toxicity and may be deliberate as a hopeful applicant for renal therapy.

Cross Talk Between TGF-ß and JAK Expressions and Nepherotoxicity Induced by Tetrachloromethane: Role of Phytotherapy.

The aim of the current study is to assess the effectiveness of milk thistle seeds (Mth) in combination with Taraxacum officinale (Tof) and/or Camellia sinensis (Csin) against tetrachloromethane (Tcm) renotoxicity in rats. Tetrachloromethane was injected in a single dose, followed by 1-month treatments with Mth, Tof, and Csin alone or in combination. Serum urea, uric acid, and creatinine levels were significantly increased matched with the control group. Masson trichrome stain revealed increase in the deposition of fibrous tissue in the interstitium between the tubules and the renal corpuscles. Immunohistochemical analysis of kidney tissues revealed that Tcm induced an increase in the immune response of tumor growth factor ß (TGF-ß) and Janus kinase (JAK) protein expressions and cysteine-aspartic acid protease 3 (caspase 3), while B-cell lymphoma 2 (Bcl2) was downregulated. Treatment with the antioxidants in question either alone or in combination ameliorated all kidney function parameters and showed mild immune reactivity toward TGF-ß and JAK protein expressions in blood vessels and glomeruli in the kidney tissues and downregulated caspase 3 and activated Bcl2 protein expression. The combination regimen of the 3 antioxidants showed the most significant renoprotective effect. This was also confirmed histopathologically. It was concluded that the antioxidant mixture is considered as a promising candidate toward renal dysfunction and immune reactivity induced by Tcm and other toxicants.

Nano ubiquinone: Promising candidate for treatment of renal toxicity induced by over dose of paracetamol.

Over doses of Paracetamol (panadol; acetaminophen) can cause life-threatening renal damage. This study compared the impact of nano-ubiquinone (Nubiq) with native ubiquinone (ubiq) reducing damage induced by Paracetamol-toxicity in rats. Paracetamol treatment produced an elevation in serum urea, uric acid, creatinine, C-reactive protein, renal nitric oxide, and lipid peroxide levels, and reductions in interleukin-10, superoxide dismutase, and glutathione levels. Meanwhile, c-Jun N-terminal kinases, vascular cell adhesion protein-1, cyclooxygenase-2 protein, and kidney injury molecule-1 were highly expressed, and NFE2-related factor 2 gene expression was down-regulated. Destruction of the epithelium, necrosis, and inflammatory cell infiltration could be observed in the renal tissue. Treatment with both ubiq an nubiq significantly ameliorated all of these signs. These findings suggest that Nubiq achieved the most significant amelioration in oxidative stress and inflammatory biomarkers in paracetamol -induced nephrotoxicity.

Evaluation of the renoprotective effect of nano turmeric against toxic dose of copper sulfate: Role of vascular cell adhesion molecule-1, kidney injury molecule-1, and signal transducer and activator of transcription 3 protein expressions.

The aim of this study was to compare the potential renoprotective effects of turmeric (TM) and nano turmeric (NTM) with those of desferrioxamine (DSM) against copper sulfate (CS)-induced toxicity. Rats were administered a toxic dose of CS with TM, NTM, and DSM for 1 week. Next, serum-urea creatinine, uric acid, interleukin (IL)-10, c-reactive protein (CRP), and caspase-3 levels; renal nitric oxide (NO), glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), vascular cell adhesion molecule-1 (VCAM-1), kidney injury molecule (KIM)-1, signal transducer and activator of transcription 3 (STAT-3) protein expression; and nuclear factor (NF)-κB and B-cell lymphoma -2 (Bcl-2) messenger RNA expression levels were estimated. Administration of the investigated antioxidants downregulated the marked increase in urea, creatinine, uric acid, CRP, caspase-3, NO, MDA, VCAM-1, kidney injury molecule (KIM-1), STAT-3, NF-κB, and DNA fragmentation, and increased Bcl-2, IL-10, GSH, and SOD levels induced by CS. The histopathological examination confirmed the effects of the antioxidants on the investigated biochemical parameters. Interestingly, NTM exhibited a superior renoprotective effect, which was comparable with that of DSM. In conclusion, NTM was shown to be a promising candidate against CS-induced toxicity, and several molecular mechanisms were implicated in the CS-induced renotoxicity as well as the treatment effects of NTM.

Quercetin and Idebenone Ameliorate Oxidative Stress, Inflammation, DNA damage, and Apoptosis Induced by Titanium Dioxide Nanoparticles in Rat Liver.

Titanium dioxide nanoparticles (TiO2-NPs) are extensively used in a wide range of applications; however, many reports have investigated their nanotoxicological effect at the molecular level either in vitro or in vivo systems. The defensive roles of quercetin (Qur) or idebenone (Id) against the hepatotoxicity induced by TiO2-NPs were evaluated in the current study. The results showed that the coadministration of Qur or Id to rats intoxicated with TiO2-NPs markedly ameliorated the elevation in hepatic malondialdehyde (MDA), serum alanine amino-transferase (ALT), glucose, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), immunoglobin G (IgG), and C-reactive protein (CRP) levels compared to their levels in TiO2-NPs-treated rats. The aforementioned antioxidants also effectively modulated the changes in the levels of serum vascular endothelial growth factor (VEGF), nitric oxide (NO), hepatic DNA breakage, caspase-3, and inhibition of drug metabolizing enzymes (cytochrome P450s; CYP4502E12E1) in rat livers induced by TiO2-NPs toxicity. The histopathological examination of the liver section showed that TiO2-NPs caused severe degeneration of most hepatocytes with an increase in collagen in the portal region, while treatment with the antioxidants in question improved liver architecture. These outcomes supported the use of Qur and Id as protective agents against the hepatotoxicity induced by TiO2-NPs and other hepatotoxic drugs.

Amelioration of the Protein Expression of Cox2, NFκB, and STAT-3 by Some Antioxidants in the Liver of Sodium Fluoride-Intoxicated Rats.

The present study aimed to explore the efficiency of N-acetyl cysteine (NACC) or thymoquinone (TMQ) alone or in combination in the downregulation of inflammatory molecule expression and decreasing hepatic injury in response to sodium fluoride (SF). Sodium fluoride upregulated serum alanine and aspartate transferases activities, tumor necrosis factor α and hepatic malondialdehyde and nitric oxide levels, and the expression of cyclooxygenase 2, nuclear factor κB cell, and signal transducer and activator of transcription 3. In contrast, hepatic glutathione level, superoxide dismutase activity, and nuclear factor erythroid 2-related factor 2 expression were decreased. However, the concurrent treatment with antioxidants, alone or in combination, modulated the levels of these parameters. Histopathological examination revealed that SF treatment resulted in focal areas of massive hepatic degeneration and many degenerated hepatocytes, whereas the treatment with TMQ or NACC exhibited moderate improvement in cellular degeneration of the liver with many abnormal cells. Rats receiving a combination of TMQ and NACC showed marked improvement in cellular degeneration of liver with apparently normal hepatic architecture with very few degenerated hepatocytes. The results also revealed that the combination of TMQ and NACC is the most effective regimen in ameliorating SF toxicity, suggesting their efficacy against the toxicity of fluoride compounds. Their activities might be mediated via multiple molecular pathways.

Liposomal Curcumin Attenuates the Incidence of Oxidative Stress, Inflammation, and DNA Damage Induced by Copper Sulfate in Rat Liver.

BACKGROUND: Copper is an essential element that is used widely in agriculture as fungicides and insecticides; for example, it is used to control schistosomiasis and as an antiseptic and germicide. Copper sulfate (CuSO4) induces multiorgan dysfunction through the stimulation of reactive oxygen species and oxidative stress. Despite the numerous pharmacological effects of curcumin (CUR), its pharmacokinetic properties are less promising. Hence, there is an urgent need for novel, effective strategies to attenuate heavy metal toxicity and consequently improve the treatment efficiency. Liposomal curcumin (L-CUR) improves the dissolution, stability, and bioavailability of treatment agents. This study compared the efficacy of CUR and L-CUR with that of desferrioxamine (DES), which is a heavy metal chelator against CuSO4 hepatotoxicity. METHODS: All treatments with the aforementioned antioxidants were administered for 7 days along with CuSO4. Serum levels of alanine aminotransferase, aspartate transaminase, lactate dehydrogenase, and C-reactive protein, hepatic nitric oxide (NO), and lipid peroxides (malondialdehyde) were measured; protein expression of cyclooxygenase 2 and DNA fragmentation were evaluated. Histopathological examinations were also conducted. RESULTS: A toxic dose of CuSO4 induced elevations in the previously measured parameters; these increases were reduced by the tested antioxidants, whereas glutathione (GSH) and superoxide dismutase (SOD) levels were decreased. Treatment with the antioxidants in question modulated these levels. Liposomal CUR has more hepatoprotective efficiency than CUR, and its efficacy was similar to that of DES. The histopathological examinations confirmed these results. CONCLUSIONS: Liposomal CUR may be useful for the prevention of CuSO4-induced liver injury. Cyclooxygenase 2 protein expression and DNA fragmentation were involved in CuSO4 toxicity and treatment.

Role of N-Acetylcysteine and Coenzyme Q10 in the Amelioration of Myocardial Energy Expenditure and Oxidative Stress, Induced by Carbon Tetrachloride Intoxication in Rats.

This study is designed to evaluate the potential impact of N-acetyl cysteine (NAC) and coenzyme Q10 (CoQ10) each alone or in combination against carbon tetrachloride (CCl4)-induced cardiac damage in rats. Animals were treated with CCl4 in single intraperitoneal dose of 1 mL/Kg body weight; CCl4-intoxicated animals were pretreated with 20 mg/kg/d NAC or pretreated with 200 mg/kg/d CoQ10 or NAC and CoQ10 with the same previously mentioned doses. Carbon tetrachloride-intoxicated rats showed a significant elevation in nitric oxide and lipid peroxides and downregulation in reduced glutathione level and calcium adenosine triphosphatase. Cardiac glycolytic enzymes levels such as lactate dehydrogenase, phosphofructokinase, and hexokinase were declined coupled with a reduction in glucose content after CCl4 treatment. Moreover, myocardial hydroxyproline level was significantly increased after CCl4-treatment indicating accumulation of interstitial collagen. N-acetyl cysteine and/or CoQ10 effectively alleviated the disturbances in myocardial oxidative stress and antioxidant markers. These antioxidants effectively upregulated the reduction in cardiac energetic biomarkers due to CCl4 treatment. N-acetyl cysteine and/or CoQ10 significantly decreased hydroxyproline level compared to that of CCl4-treated rats. The current data showed that the aforementioned antioxidants have a remarkable cardioprotective effect, suggesting that they may be useful as prophylactic agents against the detrimental effects of cardiotoxins.

Amelioration of panadol-induced nephrotoxicity via down-regulation of Bax/Bcl2 ratio with some antioxidants.

BACKGROUND: Overdoses of Panadol (APAP) result in hepatic and renal toxicity. Up till now, there is no effective drug for APAP-enhanced nephrotoxicity. This work aims to explore the protective effects of N-acetylcysteine, Thymoquinone (THQ), Curcumin (CUR) and α-Lipoic acid (LA) either alone or in combination against APAP nephrotoxicity, focused on modulation of Bax/Bcl2 pathway. METHODS: APAP was administrated at a single dose then treated with the fore mentioned antioxidants. RESULTS: APAP administration increased serum creatinine, urea, uric acid, tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) levels compared to control group. There is a marked depletion of reduced glutathione (GSH) levels and superoxide dismutase activity (SOD), Bax level was overexpressed, whereas Bcl2 was downregulated in renal tissue. Histopathological examination of the kidney tissue supported these biochemical findings. Treatment with the fore mentioned anti-oxidants ameliorated most of the previous evaluated parameters and returned the kidney nearly to its normal architecture. CONCLUSION: The expression of Bax and Bcl2 is considered one of the mechanisms underlying APAP-induced nephrotoxicity. The administration of THQ along with CUR could be a promising antidote for APAP renal damage through their antioxidant potential.

Hepatoprotective Role of α-Lipoic acid and Thymoquinone in Acetaminophen- Induced Liver Injury: Down-Regulation of COX-2 and flt-1 Expression

ABSTRACT Acetaminophen (APAP) is a widely-used analgesic, while toxic doses of which induce liver injury. Inducible cyclooxygenase-2 (COX-2) is derived prostaglandins which play an anti-inflammatory role in acetaminophen-induced hepatotoxicity. Selective activation of vascular endothelial growth factor (VEGFR1, flt -1) on endothelial cells increased mRNA levels of hepatocyte mitogens (IL-6) and hepatocyte growth factor leading to prosurvival effects on hepatocytes. The aim of this study was to compare the hepatoprotective effect of N-acetylcysteine (NAC; the antidote for APAP) with that of α-Lipoic acid (ALA) and/or Thymoquinone (THQ) either alone or in combination on liver injury induced by APAP. APAP administration elevated most of the previously measured parameters and decreased GSH, SOD, and total protein levels compared with the control group. Liver sections of H&E demonstrate liver injury characterized by centrilobular hepatocellular necrosis, COX-2, and flt-1 expressions were also increased. Treatment with all fore mentioned antioxidants ameliorated most of the altered parameters compared to APAP-treated group. Treatment with the combination of ALA and THQ was the most effective therapy in the attenuation of liver injury assessed by a decrease in ALT and ALP activities and down-regulation of COX-2 and flt-1 expression. Section of liver from rat received APAP, ALA and THQ shows a marked improvement of hepatic degeneration which restricted to few hepatocytes with mild vacuolation of their cytoplasm while the nuclei appear normal mimic to control cells. It was concluded that the natural antioxidants such as ALA and THQ, may be considered as a potential antidote in combating liver injury induced by APAP.