Polydatin protects against acute cholestatic liver injury in mice via the inhibition of oxidative stress and endoplasmic reticulum stress

Mechanisms of polydatin against spinal cord ischemia-reperfusion injury based on network pharmacology, molecular docking and molecular dynamics simulation

BACKGROUND

Polydatin has shown considerable pharmacological activities in ischemia-reperfusion injuries of various organs. However, its effects and mechanisms in spinal cord ischemia-reperfusion injury have not been fully established. In this study, the mechanisms of polydatin against spinal cord ischemia-reperfusion injury were investigated via network pharmacology, molecular docking and molecular dynamics simulation.

METHODS

Spinal cord ischemia-reperfusion injury-related targets were obtained from the GeneCards database, while polydatin-related action targets were obtained from the CTD and SwissTarget databases. A protein-protein interaction network of potential targets was constructed using the String platform. After selecting the potential key targets, GO functional enrichment and KEGG pathway enrichment analyses were performed via the Metascape database, and a network map of "drug-target-pathway-disease" constructed. The relationships between polydatin and various key targets were assessed via molecular docking. Molecular dynamics simulation was conducted for optimal core protein-compound complexes obtained by molecular docking.

RESULTS

Topological analysis of the PPI network revealed 14 core targets. GO functional enrichment analysis revealed that 435 biological processes, 12 cell components and 29 molecular functions were enriched while KEGG pathway enrichment analysis revealed 91 enriched signaling pathways. Molecular docking showed that polydatin had the highest binding affinity for MAPK3, suggesting that MAPK3 is a key target of polydatin against spinal cord ischemia-reperfusion injury. Molecular dynamics simulations revealed good binding abilities between polydatin and MAPK3.

CONCLUSIONS

Polydatin exerts its effects on spinal cord ischemia-reperfusion injury through multiple targets and pathways. MAPK3 may be a key target of polydatin in spinal cord ischemia-reperfusion injury.

Pregnane X receptor agonist nomilin extends lifespan and healthspan in preclinical models through detoxification functions

Citrus fruit has long been considered a healthy food, but its role and detailed mechanism in lifespan extension are not clear. Here, by using the nematode C. elegans, we identified that nomilin, a bitter-taste limoloid that is enriched in citrus, significantly extended the animals' lifespan, healthspan, and toxin resistance. Further analyses indicate that this ageing inhibiting activity depended on the insulin-like pathway DAF-2/DAF-16 and nuclear hormone receptors NHR-8/DAF-12. Moreover, the human pregnane X receptor (hPXR) was identified as the mammalian counterpart of NHR-8/DAF-12 and X-ray crystallography showed that nomilin directly binds with hPXR. The hPXR mutations that prevented nomilin binding blocked the activity of nomilin both in mammalian cells and in C. elegans. Finally, dietary nomilin supplementation improved healthspan and lifespan in D-galactose- and doxorubicin-induced senescent mice as well as in male senescence accelerated mice prone 8 (SAMP8) mice, and induced a longevity gene signature similar to that of most longevity interventions in the liver of bile-duct-ligation male mice. Taken together, we identified that nomilin may extend lifespan and healthspan in animals via the activation of PXR mediated detoxification functions.

Dietary Polyphenols Alleviate Autoimmune Liver Disease by Mediating the Intestinal Microenvironment: Challenges and Hopes

Autoimmune liver disease is a chronic liver disease caused by an overactive immune response in the liver that imposes a significant health and economic cost on society. Due to the side effects of existing medicinal medications, there is a trend toward seeking natural bioactive compounds as dietary supplements. Currently, dietary polyphenols have been proven to have the ability to mediate gut-liver immunity and control autoimmune liver disease through modulating the intestinal microenvironment. Based on the preceding, this Review covers the many forms of autoimmune liver illnesses, their pathophysiology, and the modulatory effects of polyphenols on immune disorders. Finally, we focus on how polyphenols interact with the intestinal milieu to improve autoimmune liver disease. In conclusion, we suggest that dietary polyphenols have the potential as gut-targeted modulators for the prevention and treatment of autoimmune liver disease and highlight new perspectives and critical issues for future pharmacological applications.

Polydatin: A Critical Promising Natural Agent for Liver Protection via Antioxidative Stress

Polydatin, one of the natural active small molecules, was commonly applied in protecting and treating liver disorders in preclinical studies. Oxidative stress plays vital roles in liver injury caused by various factors, such as alcohol, viral infections, dietary components, drugs, and other chemical reagents. It is reported that oxidative stress might be one of the main reasons in the progressive development of alcohol liver diseases (ALDs), nonalcoholic liver diseases (NAFLDs), liver injury, fibrosis, hepatic failure (HF), and hepatocellular carcinoma (HCC). In this paper, we comprehensively summarized the pharmacological effects and potential molecular mechanisms of polydatin for protecting and treating liver disorders via regulation of oxidative stress. According to the previous studies, polydatin is a versatile natural compound and exerts significantly protective and curative effects on oxidative stress-associated liver diseases via various molecular mechanisms, including amelioration of liver function and insulin resistance, inhibition of proinflammatory cytokines, lipid accumulation, endoplasmic reticulum stress and autophagy, regulation of PI3K/Akt/mTOR, and activation of hepatic stellate cells (HSCs), as well as increase of antioxidant enzymes (such as catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), superoxide dismutase (SOD), glutathione reductase (GR), and heme oxygenase-1 (HO-1)). In addition, polydatin acts as a free radical scavenger against reactive oxygen species (ROS) by its phenolic and ethylenic bond structure. However, further clinical investigations are still needed to explore the comprehensive molecular mechanisms and confirm the clinical treatment effect of polydatin in liver diseases related to regulation of oxidative stress.

Portulaca oleracea methanolic extract attenuate bile duct ligation-induced acute liver injury through hepatoprotective and anti-inflammatory effects

Introduction

Cholestasis is a liver disease caused by a malfunction of the hepato-biliary system. Oxidative stress as a systemic complication is the main characteristic of cholestasis. The aim of this study was to evaluate the anti-inflammatory and hepatoprotective effects of Portulaca oleracea (PO) methanolic extract on liver dysfunction and tissue damage induced by bile duct ligation (BDL) in rats.

Materials and methods

Twenty-eight male Wistar rats were randomly divided into four groups: sham control (SC), BDL alone, SC plus 500 mg/kg methanolic extract of PO orally for 1 week, and BDL plus 500 mg/kg methanolic extract of PO orally for 1 week. After 1 week, the animals were anesthetized, and the liver and blood samples were taken from each animal. Biochemical parameters, oxidative stress biomarkers, histopathological changes, as well as the gene expression of IL-1, TNF-α, TGF-β, and α-SMA have been evaluated.

Results

The methanolic extract of PO at a dose of 500 mg/kg significantly decreased the plasma levels of aminotransferases, alkaline phosphatase as compared to BDL group (P < 0.05), while it had no significant effect on the levels of oxidative stress markers in the hepatic tissue. The plasma level of malondialdehyde and ferric-reducing antioxidant power were markedly elevated in the BDL group in comparison to SC group (P < 0.05), while treatment with PO significantly reduced these markers (P < 0.05). The administration of PO attenuated hydroxyproline content, bile duct proliferation, and inflammation score in the cholestatic liver in contrast to non-treated BDL rats (P < 0.05). Moreover, the methanolic extract of PO markedly declined the expression of TNF-α and TGF-β pro inflammatory genes in contrast to BDL rats.

Conclusions

Taken together, our findings showed that PO attenuated liver injury by decreasing liver function tests, inflammation, and hydroxyproline content. As a result, it is suggested that PO can be applied in cholestatic liver damage as a therapeutic or adjuvant agent.

Hepatoprotective Effects of Polydatin-Loaded Chitosan Nanoparticles in Diabetic Rats: Modulation of Glucose Metabolism, Oxidative Stress, and Inflammation Biomarkers

Polydatin (PD) has a broad range of pharmacological activities; however, its effects on diabetic liver damage are poorly studies. This work is aimed to explore possible protective effects of polydatin-loaded chitosan nanoparticles (PD-CSNPs) or PD against liver damage associated with diabetes. Diabetes was induced in rats using nicotinamide/streptozotocin treatment. Diabetic rats were then divided into six groups: normal control rats, diabetic control rats, and rats orally treated with PD, PD-CSNPs, equivalent unloaded CSNPs, or metformin daily for 4 weeks. Treatment with PD and PD-CSNPs significantly reduced the blood glucose content, lipid peroxidation in the liver, and activities of serum transaminases and carbohydrate metabolism enzymes (including succinate dehydrogenase and pyruvate kinase); by contrast, liver glycogen content, glutathione concentration, and activities of the antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase, and glucose-6-phosphate dehydrogenase) were markedly increased compared with the control diabetic rats. Furthermore, expression of the tumor necrosis factor α and interleukin-1β mRNAs was significantly downregulated, while expression of glucose transporter 2 and glucokinase mRNAs was strongly upregulated vs. control diabetic rats. We concluded that PD-CSNPs and PD ameliorate diabetic liver damage by modulating glucose transporter 2 expression, affecting the activity of carbohydrate metabolism enzymes, and suppressing oxidative stress and inflammation, PD-CSNPs being more efficient than PD, probably due to higher bioavailability and prolonged release.

Antioxidant and Anti-Inflammatory Effects of Origanum majorana L. Methanolic Extract on Bile Duct Ligation in Male Rats

INTRODUCTION

Cholestasis is caused by malfunction of the hepatobiliary system. This disorder is the result of the accumulation of bile fatty acids and other toxins in the liver. The aim of the current study was to investigate the antioxidative and hepatoprotective effects of methanolic extract of Origanum majorana L. (OM) on hepatic disorder and tissue damage induced by bile duct ligation (BDL) in rats. Materials and methods. Twenty-eight male Wistar rats were randomly divided into 4 groups including sham control group received vehicle (SC-V), bile duct ligation received vehicle (BDL-V), bile duct ligation group received OM extract (BDL + OM), and sham control group received OM extract (SC + OM). One day after surgery, the animals received vehicle or methanolic extract of OM 300 mg/kg/day for 7 consecutive days by oral gavage. Finally, the animals were anesthetized and the blood samples were collected from each animal. After sacrificing of animals, liver tissue from each rat was removed and divided into three parts: one part was used for preparing of homogenized tissue, one part was fixed in 10% neutral formalin for histopathology examination, and the third part was kept in liquid nitrogen for gene expression analysis. Biomarkers of oxidative stress in the liver tissue and serum, as well as histopathological changes of the liver, were assessed. Also, the gene expression of IL-1, TNF-α, TGF-β, and α-SMA has been measured.

RESULTS

The results showed that BDL-V significantly increased the activity of ALT, AST, ALP, and total bilirubin compared to the SC-V group. The oxidative stress markers such as MDA and FRAP significantly increased due to BDL, while the CAT activity reduced in the BDL-V group compared to SC-V group. Oral treatment with OM reduced ALT and AST activity, although it was not statistically significant. OM treatment considerably increased the activity of CAT compared to BDL group. BDL-V induced a significant histological change in the liver, while treatment with OM at a dose of 300 mg/kg showed a minor effect on histopathological changes. In addition, the mRNA of IL-1, TNF-α, TGF-β, and α-SMA significantly increased in the BDL-V group, while treatment with OM only significantly reduced TGF-β in comparison with BDL-V rats.

CONCLUSIONS

The results of the present study showed that oral administration of OM extract had a moderate protective effect on cholestasis due to BDL. Indeed, more studies with different doses of extract are needed to confirm this finding.

SIRT1 provides new pharmacological targets for polydatin through its role as a metabolic sensor

The SIRT family of proteins constitutes highly conserved deacetylases with diverse and extensive functions. These proteins have specific biological functions, including regulation of transcription, cell cycle, cell differentiation, apoptosis, stress, metabolism, and genomic stability. Polydatin is a monocrystalline compound isolated from a Chinese herb, Polygonum cuspidatum. The pharmacological mechanisms of polydatin are mostly unclear but involve members of the SIRT protein family, among which SIRT1 plays a vital role. Polydatin is usually considered a potential SIRT1 activator. This review summarizes the signaling mechanism of polydatin involving SIRT1 and discusses the roles of related signal molecules such as PGC-1α, Nrf2, p38-MAPK, NLPR3 inflammasome, and p53. Further, we describe the metabolic regulation of related biological macromolecules and demonstrate that SIRT1, as a metabolic sensor, may act as a new pharmacological target for polydatin.

Polydatin-loaded chitosan nanoparticles ameliorates early diabetic nephropathy by attenuating oxidative stress and inflammatory responses in streptozotocin-induced diabetic rat

In various developed countries, diabetic nephropathy (DN) is the principal cause of end-stage kidney disease and a main reason of injury and mortality in individuals with renal morbidity worldwide. Polydatin (POL) has been evaluated as a potential antioxidant, anti-inflammatory and a nephroprotective agent. In spite of this, the possible benefits and protective effects of POL on early diabetic nephropathy are not quite clarified. For the effective clearance from the body besides safe drug delivery, biodegradable nanoparticles have interesting attraction. This work was designed to evaluate the positive effect and possible mechanisms of Polydatin-loaded Chitosan-Nanoparticles (POL-NPs) on early DN in streptozotocin-induced diabetic rats. Followed the induction of diabetes, rats classified into four groups, diabetic control and diabetic rats treated daily and orally with; POL, Polydatin-loaded chitosan-Nanoparticles (POL-NPs), plus normal control rats. Our findings showed that diabetic group presented a significant high level of the blood glucose, blood glycosylated hemoglobin (HbA1c), serum insulin, renal function related parameters, renal Advanced glycation-end products (AGEs) and lipid peroxidation level compared to normal control rats, while serum albumin level and the activities of renal antioxidant enzymes were significantly decreased. Moreover, in the kidney of diabetic rat mRNA expression of nuclear factor-kappa B (NF-κB) and cyclooxygenase-2 (Cox-2) were up-regulated. Besides, increase in serum levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-18) and decrease in anti-inflammatory cytokine (IL-10). POL and POL-NPs supplementation were significantly attenuate the above-mention results and returned the normal equilibrium between pro- and anti-inflammatory cytokines. In conclusion, POL and POL-NPs have antidiabetic effect, suppresses oxidative stress and mitigates renal inflammation through inhibition of NF-κB in diabetic kidney in early progressive DN.

Polydatin attenuates cadmium-induced oxidative stress via stimulating SOD activity and regulating mitochondrial function in Musca domestica larvae

Cadmium (Cd) is a widespread environment contaminant due to the development of electroplating and metallurgical industry. Cd can be enriched by organisms via food chain, causing the enlarged environmental problems and posing threats to the health of humans. Polydatin (PD), a natural stilbenoid compound derived from Polygonum cuspidatum, shows pronouncedly curative effect on oxidative damage. In this work, the protective effects of PD on oxidative damage induced by Cd in Musca domestica (housefly) larvae were evaluated. The larvae were exposed to Cd and/or PD, subsequently, the oxidative stress status, mitochondria activity, oxidative phosphorylation efficiency, and survival rate were assessed. Cd exposure generated significant increases of malondialdehyde (MDA), reactive oxygen species (ROS) and 8-hydroxy-2-deoxyguanosine (8-oxoG) in the housefly larvae, causing mitochondrial dysfunction and survival rate decline. Interestingly, pretreatment with PD exhibited obviously mitochondrial protective effects in the Cd-exposed larvae, as evidenced by reduced MDA, ROS and 8-oxoG levels, and increased activities of superoxide dismutase (SOD), mitochondrial electron transfer chain, and mitochondrial membrane potential, as well as respiratory control ratio. These results suggested that PD could attenuate Cd-induced damage via maintaining redox balance, stimulating SOD activity, and regulating mitochondria activity in housefly larvae. As a natural polyphenolic chemical, PD can act as a potential candidate compounds to relieve Cd injury.