Combination of metformin and luteolin synergistically protects carbon tetrachloride-induced hepatotoxicity: Mechanism involves antioxidant, anti-inflammatory, antiapoptotic, and Nrf2/HO-1 signaling pathway

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

JOURNAL/nrgr/04.03/01300535-202409000-00037/figure1/v/2024-01-16T170235Z/r/image-tiff Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models. Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis. Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis. Previous studies have shown that, when used to treat cardiovascular and digestive system diseases, metformin can also upregulate heme oxygenase-1 expression. Therefore, we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury. To test this, we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury. Next, we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis. Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury. Subsequently, we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord, and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury. Taken together, these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury, and that this effect is partially dependent on upregulation of heme oxygenase-1.

Anti-Tumor Effects and Toxicity Reduction Mechanisms of Prunella vulgaris: A Comprehensive Review

PURPOSE

To investigate and systematically describe the mechanism of action of Prunella vulgaris (P. vulgaris) against digestive system tumors and related toxicity reduction.

METHODS

This study briefly describes the history of medicinal food and the pharmacological effects of P. vulgaris, focusing on the review of the anti-digestive tumor effects of the active ingredients of P. vulgaris and the mechanism of its toxicity reduction.

RESULTS

The active ingredients of P. vulgaris may exert anti-tumor effects by inducing the apoptosis of cancer cells, inhibiting angiogenesis, inhibiting the migration and invasion of tumor cells, and inhibiting autophagy. In addition, P. vulgaris active ingredients inhibit the release of inflammatory factors and macrophages and increase the level of indicators of oxidative stress through the modulation of target genes in the pathway to achieve the effect of toxicity reduction.

CONCLUSION

The active ingredients in the medicine food homology plant P. vulgaris not only treat digestive system tumors through different mechanisms but also reduce the toxic effects. P. vulgaris is worthy of being explored more deeply.

Phytochemical Profiling and Antioxidant Activities of the Most Favored Ready-to-Use Thai Curries, Pad-Ka-Proa (Spicy Basil Leaves) and Massaman

Food is one of the factors with the highest impact on human health. Today, attention is paid not only to food properties such as energy provision and palatability but also to functional aspects including phytochemical, antioxidant properties, etc. Massaman and spicy basil leaf curries are famous Thai food dishes with a good harmony of flavor and taste, derived from multiple herbs and spices, including galangal rhizomes, chili pods, garlic bulbs, peppers, shallots, and coriander seeds, that provide an array of health benefits. The characterization of phytochemicals detected by LC-ESI-QTOF-MS/MS identified 99 components (Masaman) and 62 components (spicy basil leaf curry) such as quininic acid, hydroxycinnamic acid, luteolin, kaempferol, catechin, eugenol, betulinic acid, and gingerol. The cynaroside and luteolin-7-O-glucoside found in spicy basil leaf curry play a key role in antioxidant activities and were found at a significantly higher concentration than in Massaman curry. Phenolic and flavonoid compounds generally exhibit a bitter and astringent taste, but all the panelists scored both curries higher than 7 out of 9, confirming their acceptable flavor. Results suggest that the Massaman and spicy basil leaves contain various phytochemicals at different levels and may be further used as functional ingredients and nutraceutical products.

Metformin exerts anti-liver fibrosis effect based on the regulation of gut microbiota homeostasis and multi-target synergy

Liver fibrosis can progress to cirrhosis if left untreated. Therefore, identifying effective antifibrotic drugs is crucial. This study aimed to investigate the role and potential mechanism of metformin in treating hepatic fibrosis based on the synergistic effect of multiple targets and the "intestine-liver axis" theory. A CCl4-induced liver fibrosis mouse model was established. We measured liver function, liver fibrosis indicators, oxidative stress and inflammation indices. Hematoxylin and eosin and Masson's trichrome staining were used to detect collagen deposition. The expression of apoptotic proteins, TGF-β/Smads and TIMP-1/MMPs was assessed. 16S rRNA and untargeted metabolomics (liquid chromatography-mass spectrometry) were used to assess mouse intestinal flora and metabolites, performing a comprehensive correlation analysis. Metformin improved the general status and liver function and decreased liver collagen deposition in CCl4-induced liver fibrotic mice. Compared with the control group, IL-6, TNF-α and COX-2 serum levels in the liver fibrosis group increased. Although not significantly different, the serum inflammatory marker levels in the metformin group were lower than those in the model group. Metformin decreased serum MDA and increased serum SOD activity, which increased and decreased, respectively, in the model group. Furthermore, metformin inhibited liver cell apoptosis, TGF-β1 expression and TIMP-1, while promoting Smad7 expression, MMP-1 and MMP-2 in fibrotic mice. 16S rRNA analysis indicated that metformin significantly ameliorated the Bacteroides, Helicobacter, Parabacteroides and Parasutterella imbalance. We identified 385 differential metabolites between the metformin and model groups. Prevotella abundance significantly decreased in the metformin group and positively correlated with decreased taurocholic acid levels. Metformin potentially reverses liver fibrosis by inhibiting inflammation, mitigating oxidative stress damage and suppressing hepatocyte apoptosis via intestinal flora metabolite regulation. Metformin also regulates the TGF-β/Smads and TIMP-1/MMPs signalling pathways. This study provides a theoretical basis for the clinical use of metformin in patients with liver fibrosis.

Nrf2 Pathway and Oxidative Stress as a Common Target for Treatment of Diabetes and Its Comorbidities

Diabetes is a chronic disease that induces many comorbidities, including cardiovascular disease, nephropathy, and liver damage. Many mechanisms have been suggested as to how diabetes leads to these comorbidities, of which increased oxidative stress in diabetic patients has been strongly implicated. Limited knowledge of antioxidative antidiabetic drugs and substances that can address diabetic comorbidities through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway calls for detailed investigation. This review will describe how diabetes increases oxidative stress, the general impact of that oxidative stress, and how oxidative stress primarily contributes to diabetic comorbidities. It will also address how treatments for diabetes, especially focusing on their effects on the Nrf2 antioxidative pathway, have been shown to similarly affect the Nrf2 pathway of the heart, kidney, and liver systems. This review demonstrates that the Nrf2 pathway is a common pathogenic component of diabetes and its associated comorbidities, potentially identifying this pathway as a target to guide future treatments.

Construction of Phlorotannin-Based Nanoparticles for Alleviating Acute Liver Injury

Acute liver injury (ALI) is a severe health condition with limited treatment options. Phlorotannin (PT), a natural compound extracted from seaweeds, has shown potential in improving liver function. However, its poor stability and bioavailability have limited its applications in vivo. In this study, we developed PT-based nanoparticles (NPs) through a Mannich reaction with glycine, which exhibited good biocompatibility and prolonged circulation time in vivo. Our results revealed that the PT NPs possess strong free radical scavenging ability, effectively reducing reactive oxygen species (ROS) and alleviating oxidative stress and proinflammatory responses in the H2O2-induced oxidative damage model of HepG2 cells. Furthermore, the PT NPs effectively attenuated oxidative stress and inflammation in the liver tissue of carbon tetrachloride (CCl4)-induced liver injury mice by regulating the Nrf2/HO-1 signaling pathway. In summary, our results suggested that the PT NPs could serve as a promising nano-therapeutic strategy for alleviating ALI.

Nrf2-mediated therapeutic effects of dietary flavones in different diseases

Oxidative stress (OS) is a pathological status that occurs when the body's balance between oxidants and antioxidant defense systems is broken, which can promote the development of many diseases. Nrf2, a redox-sensitive transcription encoded by NFE2L2, is the master regulator of phase II antioxidant enzymes and cytoprotective genes. In this context, Nrf2/ARE signaling can be a compelling target against OS-induced diseases. Recently, natural Nrf2/ARE regulators like dietary flavones have shown therapeutic potential in various acute and chronic diseases such as diabetes, neurodegenerative diseases, ischemia-reperfusion injury, and cancer. In this review, we aim to summarize nrf2-mediated protective effects of flavones in different conditions. Firstly, we retrospected the mechanisms of how flavones regulate the Nrf2/ARE pathway and introduced the mediator role Nrf2 plays in inflammation and apoptosis. Then we review the evidence that flavones modulated Nrf2/ARE pathway to prevent diseases in experimental models. Based on these literature, we found that flavones could regulate Nrf2 expression by mechanisms below: 1) dissociating the binding between Nrf2 and Keap1 via PKC-mediated Nrf2 phosphorylation and P62-mediated Keap1 autophagic degradation; 2) regulating Nrf2 nuclear translocation by various kinases like AMPK, MAPKs, Fyn; 3) decreasing Nrf2 ubiquitination and degradation via activating sirt1 and PI3K/AKT-mediated GSK3 inhibition; and 4) epigenetic alternation of Nrf2 such as demethylation at the promoter region and histone acetylation. In conclusion, flavones targeting Nrf2 can be promising therapeutic agents for various OS-related disorders. However, there is a lack of investigations on human subjects, and new drug delivery systems to improve flavones' treatment efficiency still need to be developed.

Recent Updates on Source, Biosynthesis, and Therapeutic Potential of Natural Flavonoid Luteolin: A Review

Nature gives immense resources that are beneficial to humankind. The natural compounds present in plants provide primary nutritional values to our diet. Apart from food, plants also provide chemical compounds with therapeutic values. The importance of these plant secondary metabolites is increasing due to more studies revealing their beneficial properties in treating and managing various diseases and their symptoms. Among them, flavonoids are crucial secondary metabolite compounds present in most plants. Of the reported 8000 flavonoid compounds, luteolin is an essential dietary compound. This review discusses the source of the essential flavonoid luteolin in various plants and its biosynthesis. Furthermore, the potential health benefits of luteolins such as anti-cancer, anti-microbial, anti-inflammatory, antioxidant, and anti-diabetic effects and their mechanisms are discussed in detail. The activity of luteolin and its derivatives are diverse, as they help to prevent and control many diseases and their life-threatening effects. This review will enhance the knowledge and recent findings regarding luteolin and its therapeutic effects, which are certainly useful in potentially utilizing this natural metabolite.

The therapeutic role of nutraceuticals targeting the Nrf2/HO-1 signaling pathway in liver cancer

Liver cancer (L.C.) is the most common cause of cancer death in the United States and the fifth most common globally. The overexpression of nuclear factor E2 related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) caused by oxidative stress has been associated with tumor growth, aggressiveness, treatment resistance, and poor prognosis. Nutraceuticals that inhibit Nrf2/HO-1 signaling may become the most effective strategy to treat liver cancer. Phytochemicals found in fruits and vegetables, also known as nutraceuticals, tend to emerge as chemopreventive agents, with the added benefit of low toxicity and high nutritional values. This paper reviews the present scientific knowledge of the Nrf2/HO-1 signaling as a possible target molecule for chemotherapeutic agents, its basic control mechanisms, and Nrf2/HO-1 inducers produced from natural products that might be employed as cancer chemopreventive drugs. The growing interest in the contribution of the Nrf2/ARE/HO-1 signaling in the development of liver cancer and the Use of nutraceuticals to treat liver cancer by targeting Nrf2/ARE/HO-1. PRACTICAL APPLICATIONS: An increase in Nrf2 expression indicates that Nrf2 is the most important player in liver cancer. Cancer patients are more resistant to chemotherapy because of this erroneous Nrf2 signaling. Furthermore, an increasing body of evidence indicates that activation of the Nrf2/HO-1 pathway results in the production of phase II detoxifying and antioxidant enzymes, which serve a defense purpose in cells. As a consequence, treating liver cancer. This master regulator may be a possibility. Nutraceuticals that reduce Nrf2/HO-1 signaling may be the most effective strategy for preventing liver cancer. The methods of action of numerous natural substances are examined in this article.

Anti-Inflammatory and Active Biological Properties of the Plant-Derived Bioactive Compounds Luteolin and Luteolin 7-Glucoside

Flavonoids are interesting molecules synthetized by plants. They can be found abundantly in seeds and fruits, determining the color, flavor, and other organoleptic characteristics, as well as contributing to important nutritional aspects. Beyond these characteristics, due to their biochemical properties and characteristics, they can be considered bioactive compounds. Several interesting studies have demonstrated their biological activity in different cellular and physiological processes in high-order organisms including humans. The flavonoid molecular structure confers the capability of reacting with and neutralizing reactive oxygen species (ROS), behaving as scavengers in all processes generating this class of molecules, such as UV irradiation, a process widely present in plant physiology. Importantly, the recent scientific literature has demonstrated that flavonoids, in human physiology, are active compounds acting not only as scavengers but also with the important role of counteracting the inflammation process. Among the wide variety of flavonoid molecules, significant results have been shown by investigating the role of the flavones luteolin and luteolin-7-O-glucoside (LUT-7G). For these compounds, experimental results demonstrated an interesting anti-inflammatory action, both in vitro and in vivo, in the interaction with JAK/STAT3, NF-κB, and other pathways described in this review. We also describe the effects in metabolic pathways connected with inflammation, such as cellular glycolysis, diabetes, lipid peroxidation, and effects in cancer cells. Moreover, the inhibition of inflammatory pathway in endothelial tissue, as well as the NLRP3 inflammasome assembly, demonstrates a key role in the progression of such phenomena. Since these micronutrient molecules can be obtained from food, their biochemical properties open new perspectives with respect to the long-term health status of healthy individuals, as well as their use as a coadjutant treatment in specific diseases.

The role of flavonoids in inhibiting IL-6 and inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. RA has well-known clinical manifestations and can cause progressive disability and premature death along with socioeconomic burdens. Interleukin-6 (IL-6) has been implicated in the pathology of RA where it can stimulate pannus formation, osteoclastogenesis, and oxidative stress. Flavonoids are plant metabolites with beneficial pharmacological effects, including anti-inflammatory, antioxidant, antidiabetic, anticancer, and others. Flavonoids are polyphenolic compounds found in a variety of plants, vegetables, and fruits. Many flavonoids have demonstrated anti-arthritic activity mediated mainly through the suppression of pro-inflammatory cytokines. This review thoroughly discusses the accumulate data on the role of flavonoids on IL-6 in RA.

Antioxidant and protective effects of extra virgin olive oil incorporated with diallyl sulfide against CCl4-induced acute liver injury in mice

The present study delineates the effects of incorporation of 1% diallyl sulfide (DAS) into extra virgin olive oil (EVOO) on the physico-chemical characteristics, in vitro antioxidant, and in vivo hepatoprotective properties in CCl4-induced acute liver injury in mice. Results showed that the DAS-rich EVOO exhibited good oxidative stability over one-month storage and preserved its original quality-related parameters including major components (oleic acid, linoleic acid, and palmitic acid), and minor components (tocopherols, chlorophylls and carotenoids, tyrosol, hydroxytyrosol, elenolic acid, oleuropein and its aglycone, pinoresinol, vanilic acid, cinnamic acid, ferulic acid, luteolin, apigenin, and sterols). Compared with EVOO or DAS, the DAS-rich EVOO displayed the highest DPPH and ABTS-radical scavenging activities and showed the strongest cellular antioxidant activity (CAA). In connection with its free radical scavenging activity and CAA, DAS-rich EVOO significantly normalized the serum ALT and AST levels and prevented the increase in interleukin-6 in CCl4-intoxicated mice. The manifest anti-inflammatory and hepatoprotective effects of DAS-rich EVOO were further supported by liver histopathological examinations. Overall, the EVOO enrichment with DAS could open up opportunities for the development of novel functional food with improved antioxidant and hepatoprotective properties.

Ethanolic extract of Mucuna pruriens leaves ameliorates carbon tetrachloride and rifampicin-induced hepatotoxicity and nephrotoxicity in wistar albino rat

Background

Mucuna pruriens (L.) has been used for the treatment of several ailments in folkloric medicine. The present study therefore investigates the hepatoprotective and nephroprotective potentials of its leaves extract with a view to providing a potent alternative in the management of liver and kidney diseases.

Methodology

Forty male albino rats were randomly placed into eight groups comprising five animals each. Animals in group I were administered with the distilled water, while groups II and VI were exposed to CCl₄ and rifampicin respectively. Animals in groups III and IV were initially exposed CCl₄ and treated with 50 and 100 mg/kg bw M. pruriens respectively. Similarly, groups VII and VIII animals were exposed to rifampicin and treated with 50 and 100 mg/kg bw M. pruriens respectively. Animals in group V were treated with 100 mg/kg bw silymarin by oral gavage after an initial exposure to CCl₄. Selected biomarkers of liver and kidney damage were determined in the serum and organs homogenate. Liver and kidney slices of experimental animals were also stained for histopathological examination.

Results

Exposure to CCl₄ and rifampicin respectively resulted in marked distortion in lipid profile, inhibition of antioxidant enzymes and a surge in ALT, AST, ALP, urea, uric acid, bilirubin and creatine kinase. Treatment with M. pruriens extract reversed all deranged biochemical and histopathological parameters in a dose-dependent manner.

Conclusion

Extract of M. pruriens leaves restored deranged biochemical and histopathological parameters in the liver and kidney with similar potency to silymarin. Hence, leaf extract of M. pruriens is a potential hepatoprotective and nephroprotective agent that can be exploited in the management of liver and kidney diseases.

Paving Luteolin Therapeutic Potentialities and Agro-Food-Pharma Applications: Emphasis on In Vivo Pharmacological Effects and Bioavailability Traits

Luteolin is a naturally occurring secondary metabolite belonging to the class of flavones. As many other natural flavonoids, it is often found in combination with glycosides in many fruits, vegetables, and plants, contributing to their biological and pharmacological value. Many preclinical studies report that luteolin present excellent antioxidant, anticancer, antimicrobial, neuroprotective, cardioprotective, antiviral, and anti-inflammatory effects, and as a consequence, various clinical trials have been designed to investigate the therapeutic potential of luteolin in humans. However, luteolin has a very limited bioavailability, which consequently affects its biological properties and efficacy. Several drug delivery strategies have been developed to raise its bioavailability, with nanoformulations and lipid carriers, such as liposomes, being the most intensively explored. Pharmacological potential of luteolin in various disorders has also been underlined, but to some of them, the exact mechanism is still poorly understood. Given the great potential of this natural antioxidant in health, this review is aimed at providing an extensive overview on the in vivo pharmacological action of luteolin and at stressing the main features related to its bioavailability, absorption, and metabolism, while essential steps determine its absolute health benefits and safety profiles. In addition, despite the scarcity of studies on luteolin bioavailability, the different drug delivery formulations developed to increase its bioavailability are also listed here.

Study on the Efficacy and Mechanism of Lycium barbarum Polysaccharide against Lead-Induced Renal Injury in Mice

Lead is one of the most common heavy metal pollutants in the environment. Prolonged exposure to lead will induce oxidative stress, inflammation, and apoptosis in the kidneys, which in turn causes kidney injury. Lycium barbarum polysaccharide (LBP) is well known for its numerous pharmacological properties. This study aims to explore the efficacy and mechanism of LBP against lead-induced kidney damage in mice. Symptoms of renal injury were induced in mice by using 25 mg/kg lead acetate (PbAc₂), and different doses of LBP (200, 400, and 600 mg/kg BW) were orally administrated to PbAc₂-treated mice for five weeks. The results of the pharmacodynamics experiment showed that the renal pathological damages, serum creatinine (Cre), blood urea nitrogen (BUN), and kidney index of PbAc₂-treated mice could be significantly alleviated by treatment with LBP. Further, LBP treatment significantly increased the weight and feed intake of PbAc₂-treated mice. The dose effect results indicated that a medium dose of LBP was superior to high and low doses. The results of mechanistic experiments showed that LBP could attenuate oxidative stress, inflammation, and apoptosis in the kidneys of mice with lead toxicity by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway.

Metformin Actions on the Liver: Protection Mechanisms Emerging in Hepatocytes and Immune Cells against NASH-Related HCC

Nonalcoholic fatty liver disease (NAFLD) is strongly linked to the global epidemic of obesity and type 2 diabetes mellitus (T2DM). Notably, NAFLD can progress from the mildest form of simple steatosis to nonalcoholic steatohepatitis (NASH) that increases the risk for hepatocellular carcinoma (HCC), which is a malignancy with a dismal prognosis and rising incidence in the United States and other developed counties, possibly due to the epidemic of NAFLD. Metformin, the first-line drug for T2DM, has been suggested to reduce risks for several types of cancers including HCC and protect against NASH-related HCC, as revealed by epidemical studies on humans and preclinical studies on animal models. This review focuses on the pathogenesis of NASH-related HCC and the mechanisms by which metformin inhibits the initiation and progression of NASH-related HCC. Since the functional role of immune cells in liver homeostasis and pathogenesis is increasingly appreciated in developing anti-cancer therapies on liver malignancies, we discuss both the traditional targets of metformin in hepatocytes and the recently defined effects of metformin on immune cells.

Metformin Ameliorates Gestational Diabetes Mellitus-Induced Endothelial Dysfunction via Downregulation of p65 and Upregulation of Nrf2

Gestational diabetes mellitus (GDM) causes oxidative stress in mothers and infants and causes vascular endothelial dysfunction, which is a key factor for maternal and fetal cardiovascular diseases in the later stage of GDM, seriously threatening the life and health of mothers and infants. Nowadays, metformin (MET) has been discovered to improve endothelial function, but studies regarding the mechanism of MET improving endothelial cell function and alleviating endothelial function under hyperglycemia are still extremely limited. We aimed to investigate whether MET exerts its protective role against hyperglycemia-induced endothelial dysfunction through p65 and Nrf2. In our studies, applying cell migration assay and tube formation assay, we observed an obvious improvement of endothelial function under MET-treated, as characterized by that MET accelerated GDM-attenuated migration and angiogenesis of HUVECs. And ELISA assay results uncovered that Nrf2 expression level was decreased in GDM placenta, HVUECs and maternal serum comparing with normal group, however activation Nrf2 largely ameliorated tube formation under hyperglycemic condition. Furthermore, MET elevated the Nrf2 expression level and the level of nuclear Nrf2 accumulation in hyperglycemic HUVECs. Besides, preliminary evidence predicted that Nrf2 expression was modulated by transcription factor p65, which was increased in GDM peripheral blood, placenta and HUVECs, and suppression of p65 could recover GDM-induced suppression of angiogenesis. In addition, we also confirmed MET restores the GDM-induced angiogenesis impairment may via downregulation of p65 and upregulation of Nrf2. Taken together, the endothelial protective effect of MET under GDM (HG) conditions could be partly attributed to its role in downregulating p65 and upregulating Nrf2.

Luteolin protects against lead acetate-induced nephrotoxicity through antioxidant, anti-inflammatory, anti-apoptotic, and Nrf2/HO-1 signaling pathways

Lead (Pb) is one of the most common heavy metal pollutants affecting living organisms. It induces nephrotoxicity with significant alterations in renal structure and function. Luteolin (LUT) a flavonoid present in various plant products is well known for exhibiting numerous pharmacological properties. We evaluated the protective efficacy of LUT against Pb-induced renal injury in male Wistar rats. Four experimental groups: control, LUT (50 mg/kg, orally), PbAc (20 mg/kg, i.p.), LUT + PbAc (at the aforementioned doses) were maintained for 7 days. PbAc administration significantly increased renal Pb accumulation, urea, and creatinine levels in serum, and induced renal histological alterations. Additionally, compared to the control rats, PbAc-treated rats exhibited significantly low levels of antioxidant enzyme activity and expression (SOD, CAT, GPx and GR), as well as high MDA levels. Moreover, PbAc exposure downregulated Nfe212 and Homx1 mRNA expression and significantly increased inflammatory marker (TNF-α, IL-1β and NO) levels in renal tissue. PbAc significantly upregulated the synthesis of apoptotic related proteins and downregulated antiapoptotic protein expression. Notably, LUT pretreatment of PbAc-treated rats provided significant nephroprotection and reversed the alterations in the abovementioned parameters. In conclusion, LUT provided significant protection against PbAc intoxication via antioxidant, anti-inflammatory, and anti-apoptotic activities by activating the Nrf2/ARE signaling pathway.

Mast Cells in Liver Fibrogenesis

Mast cells (MCs) are immune cells of the myeloid lineage that are present in the connective tissue throughout the body and in mucosa tissue. They originate from hematopoietic stem cells in the bone marrow and circulate as MC progenitors in the blood. After migration to various tissues, they differentiate into their mature form, which is characterized by a phenotype containing large granules enriched in a variety of bioactive compounds, including histamine and heparin. These cells can be activated in a receptor-dependent and -independent manner. Particularly, the activation of the high-affinity immunoglobulin E (IgE) receptor, also known as FcεRI, that is expressed on the surface of MCs provoke specific signaling cascades that leads to intracellular calcium influx, activation of different transcription factors, degranulation, and cytokine production. Therefore, MCs modulate many aspects in physiological and pathological conditions, including wound healing, defense against pathogens, immune tolerance, allergy, anaphylaxis, autoimmune defects, inflammation, and infectious and other disorders. In the liver, MCs are mainly associated with connective tissue located in the surrounding of the hepatic arteries, veins, and bile ducts. Recent work has demonstrated a significant increase in MC number during hepatic injury, suggesting an important role of these cells in liver disease and progression. In the present review, we summarize aspects of MC function and mediators in experimental liver injury, their interaction with other hepatic cell types, and their contribution to the pathogenesis of fibrosis.