Ameliorative effect of montelukast against carbon tetrachloride-induced hepatotoxicity: Targeting NLRP3 inflammasome pathway

Targeting angiogenic and proliferative mediators by montelukast & trimetazidine Ameliorates thioacetamide-induced liver fibrosis in rats

Liver fibrosis is a significant health complication with the potential to result in serious mortality and morbidity. However, there is no standard treatment due to its complex pathogenesis. The drug montelukast reversibly and selectively antagonizes the cysteinyl-leukotrienes-1 receptor and reduces inflammation; thus, it is used in the treatment of asthma. Trimetazidine, an anti-anginal agent, selectively inhibits the activity of mitochondrial long-chain 3-ketoacyl-CoA thiolase, inhibition of free fatty acid (FFA) oxidation. This study explores the efficacy of montelukast (5 and 10 mg/kg) and trimetazidine (10-20 mg/kg) against liver fibrosis induced by thioacetamide (TAA) in rats. Impaired liver function tests were significantly improved by montelukast and trimetazidine. The antioxidant and anti-inflammatory effects of montelukast and trimetazidine were proved by the inhibition of malondialdehyde (MDA) and nitric oxide (NO) accumulation, with elevation of glutathione (GSH) and superoxide dismutase activity, decreased heat shock protein (HSP-70) expression, and a decline in interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) levels in liver tissue. Also, the antifibrotic effects were explored by reducing levels of hydroxyproline and alpha-smooth muscle actin (α-SMA) expression in liver tissue and attenuating hepatic expression of hepatic expression of angiogenic mediator vascular endothelium growth factor (VEGF) and proliferative mediator Antigen Kiel 67 (Ki-67).

Kaempferol Alleviates Hepatic Injury in Nonalcoholic Steatohepatitis (NASH) by Suppressing Neutrophil-Mediated NLRP3-ASC/TMS1-Caspase 3 Signaling

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a significant hepatic condition that has gained worldwide attention. Kaempferol (Kae), renowned for its diverse biological activities, including anti-inflammatory, antioxidant, anti-aging, and cardio-protective properties, has emerged as a potential therapeutic candidate for non-alcoholic steatohepatitis (NASH). Despite its promising therapeutic potential, the precise underlying mechanism of Kae's beneficial effects in NASH remains unclear. Therefore, this study aims to clarify the mechanism by conducting comprehensive in vivo and in vitro experiments.

RESULTS

In this study, a murine model of non-alcoholic steatohepatitis (NASH) was established by feeding C57BL/6 female mice a high-fat diet for 12 weeks. Kaempferol (Kae) was investigated for its ability to modulate systemic inflammatory responses and lipid metabolism in this model (20 mg/kg per day). Notably, Kae significantly reduced the expression of NLRP3-ASC/TMS1-Caspase 3, a crucial mediator of liver tissue inflammation. Additionally, in a HepG2 cell model induced with palmitic acid/oleic acid (PA/OA) to mimic NASH conditions, Kae demonstrated the capacity to decrease lipid droplet accumulation and downregulate the expression of NLRP3-ASC/TMS1-Caspase 3 (20 µM and the final concentration to 20 nM). These findings suggest that Kae may hold therapeutic potential in the treatment of NASH by targeting inflammatory and metabolic pathways.

CONCLUSIONS

These findings suggest that kaempferol holds potential as a promising therapeutic intervention for ameliorating non-alcoholic fatty liver disease (NAFLD).

Geraniol prevents CCl4-induced hepatotoxicity via suppression of hepatic oxidative stress, pro-inflammation and apoptosis in rats

Carbon tetrachloride (CCl4) is a classic chemical hepatotoxicant that triggers liver damage through hepatic exacerbation of oxidative stress. Geraniol (GRL) is a natural bioactive acyclic monoterpene with several pharmacological effects. We thus explored whether GRL could prevent CCl4-triggered hepatic toxicity. Rats were divided and administered GRL (100 mg/kg) and/or CCl4 (1 ml/kg of 1:1 v/v CCl4: olive oil) in Control group, GRL group, CCl4 group, GRL + CCl4 groups 2 times per week for 4 consecutive weeks. CCl4 caused significantly (p < 0.05) elevated serum activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TB), whereas the albumin (ALB) and total protein (TP) levels were significantly (p < 0.05) reduced relative to the control group. The liver activities of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) decreased significantly (p < 0.05), while malondialdehyde (MDA) level evidently elevated in comparison to the control group. The CCl4 exposure caused significant increases in proinflammatory interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), apoptotic caspase-3 and caspase-9 levels, whereas the anti-inflammatory interleukin-4 (IL-4) and interleukin-10 (IL-10) were reduced in consistent with histopathological changes compared to the control. On the contrary, the GRL administration prevented the hepatic toxicity and lesions through restoration of liver status markers, antioxidant enzyme activities, MDA, cytokines and apoptosis in comparison to the CCl4 group. Altogether, the findings reveal that GRL could abrogate CCl4-provoked hepatic toxicity via inhibition of hepatic oxidative stress, inflammation and apoptosis in rats.

Ameliorative effect of montelukast against STZ induced diabetic nephropathy: targeting HMGB1, TLR4, NF-κB, NLRP3 inflammasome, and autophagy pathways

Diabetic nephropathy (DN) is reported as one of the most serious microvascular diabetic complications and the trigger of end-stage renal disease (ESRD), underscoring the concern of any therapeutic intervention directed at ameliorating the development and progression of DN. The current study explored the renoprotective impact of montelukast (Mon) against streptozotocin (STZ)-induced DN in rats compared to a standard anti-hyperglycemic insulin (Ins) treatment. Diabetes was induced by a single dose of STZ (55 mg/kg). Diabetic rats were treated with Mon (10 and 20 mg/kg, oral gavage) for eight weeks. Mon administration for 8 weeks after induction of diabetes conferred significant dose-dependent renoprotection, independent of blood glucose levels (unlike Ins), as evidenced by the improvement in serum creatinine, and blood urea nitrogen (BUN), and ameliorated STZ-induced renal necrotic, inflammatory alterations, and renal fibrosis. Additionally, Mon treatment in diabetic rats significantly restored redox hemostasis as evidenced by malondialdehyde (MDA) and total antioxidant capacity (TAC) levels; significantly reduced the renal expression of high mobility group box (HMGB) 1, toll-like receptor (TLR) 4, nuclear factor kappa B (NF-κB) (in the nucleus), NOD-like receptor family pyrin domain containing (NLRP) 3, and interleukin (IL)-1β. Moreover, Mon administration ameliorated the dysregulation in autophagy as evidenced by p62 and microtubule-associated protein 1A/1B-light chain 3 (LC3)-II levels. In conclusion, the renoprotective effect of Mon is potentially associated with its modulatory effect on inflammatory cytokines, antioxidant properties, and autophagy.

Formulation of lipid polymer hybrid nanoparticles of the phytochemical Fisetin and its in vivo assessment against severe acute pancreatitis

Fisetin (FST) is a naturally occurring flavonol that has recently emerged as a bioactive phytochemical with an impressive array of biological activities. To the author knowledge, boosting the activity of FST against severe acute pancreatitis (SAP) through a nanostructured delivery system (Nanophytomedicine) has not been achieved before. Thereupon, FST-loaded lipid polymer hybrid nanoparticles (FST-loaded LPHNPs) were prepared through conjoined ultrasonication and double emulsion (w/o/w) techniques. Comprehensive in vitro and in vivo evaluations were conducted. The optimized nanoparticle formula displayed a high entrapment efficiency % of 61.76 ± 1.254%, high loading capacity % of 32.18 ± 0.734, low particle size of 125.39 ± 0.924 nm, low particle size distribution of 0.357 ± 0.012, high zeta potential of + 30.16 ± 1.416 mV, and high mucoadhesive strength of 35.64 ± 0.548%. In addition, it exhibited a sustained in vitro release pattern of FST. In the in vivo study, oral pre-treatment of FST-loaded LPHNPs protected against L-arginine induced SAP and multiple organ injuries in rats compared to both FST alone and plain LPHNPs, as well as the untreated group, proven by both biochemical studies, that included both amylase and lipase activities, and histochemical studies of pancreas, liver, kidney and lungs. Therefore, the study could conclude the potential efficacy of the novel phytopharmaceutical delivery system of FST as a prophylactic regimen for SAP and consequently, associated multiple organ injuries.

Dose-response effect of Montelukast on post-extraction dental socket repair and skeletal phenotype of mice

Bone metabolism and repair are directly regulated by arachidonic acid metabolites. At present, we analyzed the dose-response effects of a selective cysteinyl leukotriene receptor type-1 antagonist during bone repair after tooth extraction and on non-injured skeleton. Sixty-three 129 Sv/Ev male mice composed the groups: C-Control (saline solution); MTK2-2 mg/Kg of Montelukast (MTK) and MTK4-4 mg/Kg of MTK, daily administered by mouth throughout all experimental periods set at 7, 14, and 21 days post-operative. Dental sockets were analyzed by computed microtomography (microCT), histopathology, and immunohistochemistry. Femurs, L5 vertebra and organs were also removed for observation. Blood was collected for plasma bone and liver markers. Histopathology and microCT analysis revealed early socket repair of MTK2 and MTK4 animals, with significant increased BV/TV at days 14 and 21 compared to C. Higher plasma calcium was detected at days 7 and 21 in MTK4 in comparison to C, while phosphate was significantly increased in MTK2 in the same periods in comparison to C and MTK4. No significant differences were found regarding plasma ALP and TRAP, neither for local TRAP and Runx2 immunolabeling at the healing sockets. Organs did not present histological abnormalities. Increased AST levels have been detected in distinct groups and periods. In general, femur phenotype was improved in MTK treated animals. Collectively, MTK promoted early bone formation after tooth extraction and increased bone quality of femurs and vertebra in a time-dose-dependent manner, and should be considered as an alternative therapy when improved post-extraction socket repair or skeleton preservation is required.

Interaction of Garcinia cambogia (Gaertn.) Desr. and Drugs as a Possible Mechanism of Liver Injury: The Case of Montelukast

Overweight and obesity prevalence has increased worldwide. Apart from conventional approaches, people also resort to botanical supplements for reducing body weight, although several adverse events have been associated with these products. In this context, the present study aimed at evaluating the toxicity of Garcinia cambogia-based products and shedding light on the mechanisms involved. The suspected hepatotoxic reactions related to G. cambogia-containing products collected within the Italian Phytovigilance System (IPS) were examined. Then, an in vitro study was performed to evaluate the possible mechanisms responsible for the liver toxicity, focusing on the modulation of oxidative stress and Nrf2 expression. From March 2002 to March 2022, the IPS collected eight reports of hepatic adverse reactions related to G. cambogia, which exclusively involved women and were mostly severe. The causality assessment was probable in three cases, while it was possible in five. In the in vitro experiments, a low cytotoxicity of G. cambogia was observed. However, its combination with montelukast greatly reduced cell viability, increased the intracellular ROS levels, and affected the cytoplasmic Nrf2 expression, thus suggesting an impairment of the antioxidant and cytoprotective defenses. Overall, our results support the safety concerns about G. cambogia-containing supplements and shed light on the possible mechanisms underpinning its hepatotoxicity.

Montelukast prevents mice against carbon tetrachloride- and methionine-choline deficient diet-induced liver fibrosis: Reducing hepatic stellate cell activation and inflammation

AIMS

Montelukast is an antagonist of cysteinyl leukotriene receptor 1 (CysLTR1) that protects against inflammation and oxidative stress. However, the function of montelukast in liver fibrosis remains unknown. In this study, we examined whether the pharmacological inhibition of CysLTR1 could protect mice against hepatic fibrosis.

MATERIALS AND METHODS

Carbon tetrachloride (CCl₄) and methionine-choline deficient (MCD) diet models were used in this study. The expression of CysLTR1 in liver were detected by RT-qPCR and Western blot analysis. Liver hydroxyproline levels, fibrotic genes expression, serum biochemical indexes and inflammatory factors were used to evaluate the effect of montelukast on liver fibrosis, injury, and inflammation. In vitro, we used the RT-qPCR and Western blot analysis to assess CysLTR1 in mouse primary hepatic stellate cell (HSC) and human LX-2 cell line. The role of montelukast on HSC activation and the underlying mechaisms were determined using RT-qPCR analysis, Western blot and immunostaining assays.

KEY FINDINGS

Chronic stimulation from CCl₄ and MCD diet upregulated the mRNA and protein levels of CysLTR1 in the liver. Pharmacological inhibition of CysLTR1 by montelukast ameliorated liver inflammation and fibrosis in both models. Mechanistically, montelukast suppressed HSC activation by targeting the TGFβ/Smad pathway in vitro. The hepatoprotective effect of montelukast was also associated with reduced liver injury and inflammation.

SIGNIFICANCE

Montelukast suppressed CCl₄- and MCD-induced chronic hepatic inflammation and liver fibrosis. CysLTR1 might be a therapeutic target for treating liver fibrosis.

A feasible HPTLC method for concurrent quantitation of allopurinol-montelukast co-therapy in plasma and evaluation of their hepatic and renal effects in rats: Analytical, biochemical, and histopathological study

Recent studies presented the crucial role of montelukast (MON, a leukotriene receptor antagonist) against gouty arthritis and its protective effect on drug-induced liver and kidney injury. Allopurinol (ALO, a selective xanthine oxidase inhibitor) is also used for treatment of hyperuricemia, however, it induces hepatotoxicity and acute kidney injury. Therefore, this study introduces the first analytical/biochemical/histopathological assay for MON-ALO co-therapy and aims to: inspect the hepatic and renal impacts of ALO, MON and their combination in rats via biochemical and histopathological examinations, propose and validate a facile HPTLC method for concurrent estimation of ALO-MON binary mixture in human plasma, and employ this method to attain the targeted drugs in real rat plasma. First, the cited drugs in human plasma were simultaneously separated utilizing silica gel G 60 F₂₅₄-TLC plates. The separated bands were scanned at 268 nm demonstrating appropriate linearities (50.0-2000.0 ng band^-1 for each drug) and correlations (0.9986 and 0.9992 for ALO and MON, correspondingly). The calculated detection and quantitation limits, as well as recoveries confirmed the method's reliability. This procedure was validated, and the stability studies were achieved according to Bioanalytical Method Validation Guideline. This work was extended to investigate the possible hepatic and renal effects of ALO, MON and their co-therapy in rats. Using rat's gastric tube, the following was administered to four groups of male Wistar rats: Group Ia and Ib as control (received either saline or DMSO), Groups II, III, and IV were given MON, ALO, and MON+ALO, respectively. Good correlation between the measured biochemical parameters and the observed histopathological changes was encountered. Considerable drop in aspartate transaminase and alanine transaminase levels, in addition to lower liver damage changes were observed in the combination group compared to MON or ALO-treated groups. Regarding renal changes, ALO-MON co-therapy caused elevation in the serum creatinine and blood urea nitrogen levels when compared to controls and MON- or ALO-treated groups. Severe proteinaceous casts accumulation in kidney tubular lumen, severe congestion, and severe tubular necrosis were also noticed in the combination group. Lastly, this study suggests ALO-MON co-treatment not only as a preventive therapy against gouty arthritis but also as a new line to minimize ALO-induced hepatic injury. However, co-administration of ALO and MON should be further studied to assess the benefits and risks in various tissues, adjust the MON dosing, and monitor its nephrotoxic effect.

Jasminum humile (Linn) ameliorates CCl4-induced oxidative stress by regulating ER stress, inflammatory, and fibrosis markers in rats

Jasminum humile (Linn) is highly valued for its medicinal properties. The pulp and decoction made from its leaves are effective for skin diseases. Juice prepared from roots is used against ringworm illness. Our current study aims to illustrate the non-toxicity and protective potential of methanol extract of Jasminum humile (JHM) against CCl₄-induced oxidative stress in the liver of rats. Qualitative phytochemical screening, total flavonoids (TFC), and total phenolic content (TPC) assays were performed with JHM. The toxicity of the plant was estimated by treating female rats at different JHM doses while to assess anti-inflammatory potential of plant nine groups of male rats (six rats/group) received different treatments such as: CCl₄ only (1 ml/kg mixed with olive oil in a ratio of 3:7), silymarin (200 mg/kg) + CCl₄, different doses of JHM alone at a ratio of 1:2:4, and JHM (at a ratio of 1:2:4) + CCl₄, and were examined for different antioxidant enzymes, serum markers, and histological changes, while mRNA expression of stress, inflammatory and fibrosis markers were assessed by real-time polymerase chain reaction analysis. Different phytochemicals were found in JHM. A high amount of total phenolic and flavonoid content was found (89.71 ± 2.79 mg RE/g and 124.77 ± 2.41 mg GAE/g) in the methanolic extract of the plant. Non-toxicity of JHM was revealed even at higher doses of JHM. Normal levels of serum markers in blood serum and antioxidant enzymes in tissue homogenates were found after co-administration of JHM along with CCl₄. However, CCl₄ treatment caused oxidative stress in the liver by enhancing the levels of stress and inflammatory markers and reducing antioxidant enzyme levels, while JHM treatment showed significant (P < 0.05) downregulation was in mRNA expression of those markers. Investigation of mechanism of specific signaling pathways related to apoptosis and clinical trials to assess safety and efficacy of optimal dosage of Jasminum humile will be helpful to develop FDA-approved drug.

Hepatoprotective and cognitive-enhancing effects of hesperidin against thioacetamide-induced hepatic encephalopathy in rats

Hepatic encephalopathy (HE) is a serious neurological disorder which might occur in both acute and chronic liver injury.

AIMS

This study was carried out to explore the protective effects of hesperidin against experimentally induced HE.

MAIN METHODS

Rats were sorted into four groups each of six; Normal group, TAA group: rats were administered 350 mg/kg of TAA i.p. from day 5 to day 7. TAA+ Hesp 100 group: rats were administered hesperidin 100 mg/kg/day orally for 7 days along with i.p TAA injection 350 mg/kg from day 5 to 7. TAA+ Hesp 200 group: rats were administered hesperidin 200 mg/kg/day orally for 7 days along with i.p TAA injection 350 mg/kg from day 5 to 7. Liver function, oxidative stress biomarkers, behavioral tests in addition to histopathological examination were assessed.

KEY FINDINGS

Hesperidin efficiently mitigated TAA-induced HE as evidenced by significant reduction in liver enzymes, bile and ammonia levels in serum. Moreover, hesperidin restored oxidant/antioxidant balance as manifested by reduction in MDA content in both cerebral and hepatic tissues. Additionally, hesperidin improved motor and cognitive abilities besides tissues' architecture as demonstrated by behavioral tests and histopathology results, respectively. Hesperidin also decreased levels of NLRP3 and increased levels of Sirt1 and FOXO in both cerebral and hepatic tissues. Finally, hesperidin markedly decreased the expression of IL-1β and caspase-1 as shown by immunohistochemical results.

SIGNIFICANCE

Taken together, the hepatoprotective impact of hesperidin and its ameliorative effect on the progression of HE appear to be mediated by its modulatory influence on NLRP3/Sirt1/FOXO signaling.

Montelukast and Acute Coronary Syndrome: The Endowed Drug

Acute coronary syndrome (ACS) is a set of signs and symptoms caused by a reduction of coronary blood flow with subsequent myocardial ischemia. ACS is associated with activation of the leukotriene (LT) pathway with subsequent releases of various LTs, including LTB4, LTC4, and LTD4, which cause inflammatory changes and induction of immunothrombosis. LTs through cysteine leukotriene (CysLT) induce activation of platelets and clotting factors with succeeding coronary thrombosis. CysLT receptor (CysLTR) antagonists such as montelukast (MK) may reduce the risk of the development of ACS and associated complications through suppression of the activation of platelet and clotting factors. Thus, this critical review aimed to elucidate the possible protective role of MK in the management of ACS. The LT pathway is implicated in the pathogenesis of atherosclerosis, cardiac hypertrophy, and heart failure. Inhibition of the LT pathway and CysL1TR by MK might be effective in preventing cardiovascular complications. MK could be an effective novel therapy in the management of ACS through inhibition of pro-inflammatory CysLT1R and modulation of inflammatory signaling pathways. MK can attenuate thrombotic events by inhibiting platelet activation and clotting factors that are activated during the development of ACS. In conclusion, MK could be an effective agent in reducing the severity of ACS and associated complications. Experimental, preclinical, and clinical studies are recommended to confirm the potential therapeutic of MK in the management of ACS.