Puerarin protects mouse liver against nickel-induced oxidative stress and inflammation associated with the TLR4/p38/CREB pathway

Review on the potential roles of traditional Chinese medicines in the prevention, treatment, and postoperative recovery of age-related cataract

ETHNIC PHARMACOLOGICAL RELEVANCE

Cataract is the most common cause of blindness worldwide, a visual disorder caused by a clouded lens that seriously affects People's Daily lives. Age-related cataract (ARC) is the most common type of cataract due to long-term combined effects of many factors, and its pathogenesis is varied. At present, the surgery is the main treatment for cataracts, but it is still limited to the prevention, treatment of early cataracts and the postoperative complications care. While, its drug treatments are still in the stage of exploration and research. Traditional Chinese Medicine (TCM), a unique resource in China, is conceived under the guidance of traditional Chinese medicine theory and has little toxicity and side effects, but it has made great progress in the treatment and prevention of ARC.

AIM OF THIS REVIEW

This review presents an overview of the pathogenesis of ARC in both traditional and modern medicines and summarizes the history and therapeutic effect of TCM on ARC including their formula, crude drugs and active components, and also the other auxiliary methods.

METHODS

A number of recognized databases like SciFinder, PubMed, Science Direct, Google Scholar, and China National Knowledge Infrastructure (CNKI) were extensively explored by using keywords and phrases such as "cataract", "age-related cataract", "traditional medicine", "ethnopharmacology", "herbs", "medicinal plants", or other relevant terms, and the plants/phytoconstituents that are evaluated in the models of age-related cataract. As well as the current TCM adjuvant therapy used in the clinical treatment were summarized.

RESULTS

TCM revealed to plays an active role in treating age-related cataract, via multi-pathway and multi-target, and can treat or delay ARC by inhibiting abnormal glucose metabolism, antioxidant damage, inhibiting LEC apoptosis, and so on, which is in concordance with the good effects of the global use of TCM in clinical application. Concerning the early prevention and treatment of cataract and postoperative complications, TCM and auxiliary methods remain to achieve better clinical effects.

CONCLUSION

ARC belongs to the category of "Yuan Yi Nei Zhang" in TCM theory, showing that there are many causes of ARC including aging, and kidney-yang, spleen, sperm and blood deficiencies. At the same time, the viscera gradually decline, as well as yin or yang progressively become weak, especially in the elder people. So, TCM could be mainly based on liver, kidney, and spleen syndrome differentiation, personalizing diagnosis and treatment, following multiple targets, regulating fundamentally yin and yang, and thus justifying the advantages of Chinese medicine in the prevention and treatment of ARC.

Protective effects of puerarin on liver tissue in Salmonella-infected chicks: a proteomic analysis

Salmonella enterica is a zoonotic bacterium that not only causes serious economic losses to the livestock and poultry industries but also seriously endangers human health. Long-term indiscriminate use of antibiotics has led to drug resistance in Salmonella, and thus the identification of alternatives to antibiotics is crucial. In this study, the effects of puerarin on the S. enterica-infected chickens were investigated. A total of 360 chicks were randomly assigned as the control group (CON), the S. enterica group (S), and puerarin-treatment group (P). Chicks in the P group were fed the basal diet supplemented with 50 (P50), 100 (P100), 200 (P200), and 400 (P400) mg/kg puerarin, respectively. It was found that puerarin treatment markedly altered the serum activities of aspartate aminotransferase (AST), alanine transaminase (ALT), and superoxide dismutase (SOD), together with the malondialdehyde (MDA) and total antioxidant capacity (T-AOC) contents in the serum. The mRNA expression of IL-6, IL-1β, TNF-α, Bcl-2, and caspase-8 in the livers of S. enterica-infected chicks was increased after infection but significantly reduced after treatment with puerarin. Histologic analysis showed that puerarin effectively mitigated morphological damage in the liver caused by S. enterica. Proteomic analysis revealed that S. enterica infection led to metabolic disorders in the liver, resulting in oxidative stress, increased inflammation, and significantly elevated levels of hepatocellular carcinoma biomarkers. The findings of the filtered sequencing were verified by using quantitative PCR (qPCR). Treatment with 100 mg/mL puerarin thus effectively alleviated disordered liver metabolism, reduced inflammation and oxidative damage and significantly reduced the levels of hepatocellular carcinoma biomarkers in the liver. The results suggest that puerarin has the potential to replace antibiotics to control Salmonella infection in poultry and thus improve food safety.

Mercuric chloride induced brain toxicity in mice: The protective effects of puerarin-loaded PLGA nanoparticles

Mercury is a toxic, environmentally heavy metal that can cause severe damage to all organs, including the nervous system. The functions of puerarin include antioxidant, anti-inflammatory, nerve cell repair, regulation of autophagy, and so forth. But because of the limited oral absorption of puerarin, it affects the protective effect on brain tissue. The nano-encapsulation of Pue can improve its limitation. Therefore, this study investigated the protective effect of Pue drug-loaded PLGA nanoparticles (Pue-PLGA-nps) on brain injury induced by mercuric chloride (HgCl2 ) in mice. The mice were divided into normal saline (NS) group, HgCl2 (4 mg/kg) group, Pue-PLGA-nps (50 mg/kg) group, HgCl2  + Pue (4 mg/kg + 30 mg/kg) group, and HgCl2  + Pue-PLGA-nps (4 mg/kg + 50 mg/kg) group. After 28 days of treatment, the mice were observed for behavioral changes, antioxidant capacity, autophagy and inflammatory response, and mercury levels in the brain, blood, and urine were measured. The results showed that HgCl2 toxicity caused learning and memory dysfunction in mice, increased mercury content in brain and blood, and increased serum levels of interleukin (IL-6), IL-1β, and tumor necrosis factor-α in the mice. HgCl2 exposure decreased the activity of T-AOC, superoxide dismutase, and glutathione peroxidase, and increased the expression of malondialdehyde in the brain of mice. Moreover, the expression levels of TRIM32, toll-like receptor 4 (TLR4), and LC3 proteins were upregulated. Both Pue and Pue-PLGA-nps interventions mitigated the changes caused by HgCl2 exposure, and Pue-PLGA-nps further enhanced this effect. Our results suggest that Pue-PLGA-nps can ameliorate HgCl2 -induced brain injury and reduce Hg accumulation, which is associated with inhibition of oxidative stress, inflammatory response, and TLR4/TRIM32/LC3 signaling pathway.

Advances in Extraction, Purification, and Analysis Techniques of the Main Components of Kudzu Root: A Comprehensive Review

Kudzu root (Pueraria lobate (Willd.) Ohwi, KR) is an edible plant with rich nutritional and medicinal values. Over the past few decades, an ample variety of biological effects of Pueraria isoflavone have been evaluated. Evidence has shown that Pueraria isoflavone can play an active role in antioxidant, anti-inflammatory, anti-cancer, neuroprotection, and cardiovascular protection. Over 50 isoflavones in kudzu root have been identified, including puerarin, daidzein, daidzin, 3'-hydroxy puerarin, and genistein, each with unambiguous structures. However, the application of these isoflavones in the development of functional food and health food still depends on the extraction, purification and identification technology of Pueraria isoflavone. In recent years, many green and novel extraction, purification, and identification techniques have been developed for the preparation of Pueraria isoflavone. This review provides an updated overview of these techniques, specifically for isoflavones in KR since 2018, and also discusses and compares the advantages and disadvantages of these techniques in depth. The intention is to provide a research basis for the green and efficient extraction, purification, and identification of Pueraria isoflavone and offers investigators a valuable reference for future studies on the KR.

Associations of nickel exposure with diabetes: evidence from observational studies

The results of environmental epidemiological studies regarding the relationship between human exposure to nickel and the risk of diabetes remain controversial. Therefore, we performed a meta-analysis to investigate the relationship between nickel exposure and diabetes. PubMed, Web of Science, and Embase electronic databases were thoroughly searched from their inception to May 2023 to obtain relevant studies. The random-effects model was employed to determine pooled odds ratios (ORs) and 95% confidence intervals (CIs). Stratified and sensitivity analyses were also performed. Cochran Q test and I2 statistic were employed to assess heterogeneity between studies. Begg's and Egger's tests were employed to evaluate publication bias. The indicated studies were evaluated using the ROBINS-E risk of bias tool. The dose-response relationship between nickel in urine and diabetes risk was estimated by restricted cubic spline. A total of 12 studies with 30,018 participants were included in this study. In this meta-analysis, comparing the highest vs. lowest levels of nickel exposure, the pooled ORs for diabetes were 1.42 (95% confidence interval 1.14-1.78) for urine and 1.03 (0.57-1.86) for blood, respectively. A linear relationship between urinary nickel and diabetes risk was discovered in the dose-response analysis (P nonlinearity = 0.6198). Each 1 µg/L increase of urinary nickel, the risk of diabetes increased by 7% (OR = 1.07, 95% CI 1.04-1.10). The risk of diabetes was positively correlated with urine nickel exposure, whereas the risk was not significantly correlated with blood nickel. In the future, more high-quality prospective studies are needed to validate this conclusion.

Urinary Nickel Was Associated with the Prevalence of Diabetes: Results from NHANES

The study aimed to investigate the association between nickel exposure and the presence of diabetes (DM). The participants were analyzed from the National Health and Nutrition Examination Surveys (NHANES) 2017-2018. Urinary nickel exposure was measured using inductively coupled-plasma mass spectrometry. DM was diagnosed based on the WHO standards. The association between nickel and DM or fasting glucose was examined using multivariable linear regression models and logistic regression models. A total of 1899 participants (933 men and 966 women) were included in our study, of whom 342 (18.0%) were diagnosed with DM. There was a significant positive association between nickel level and DM (OR: 1.27, 95%CI: 1.04-1.56) after adjusting for potential confounding factors. Comparing with the lowest quartile, the highest quartile independently increased a 0.66-fold higher risk of DM (OR: 1.66, 95%CI: 1.13-2.44]). In addition, nickel exposure was independently related to the level of fasting glucose. The exposure to nickel was associated with a higher risk of DM in general population.

Chitosan@Puerarin hydrogel for accelerated wound healing in diabetic subjects by miR-29ab1 mediated inflammatory axis suppression

Wound healing is one of the major global health concerns in patients with diabetes. Overactivation of pro-inflammatory M1 macrophages is associated with delayed wound healing in diabetes. miR-29ab1 plays a critical role in diabetes-related macrophage inflammation. Hence, inhibition of inflammation and regulation of miR-29 expression have been implicated as new points for skin wound healing. In this study, the traditional Chinese medicine, puerarin, was introduced to construct an injectable and self-healing chitosan@puerarin (C@P) hydrogel. The C@P hydrogel promoted diabetic wound healing and accelerated angiogenesis, which were related to the inhibition of the miR-29 mediated inflammation response. Compared to healthy subjects, miR-29a and miR-29b1 were ectopically increased in the skin wound of the diabetic model, accompanied by upregulated M1-polarization, and elevated levels of IL-1β and TNF-α. Further evaluations by miR-29ab1 knockout mice exhibited superior wound healing and attenuated inflammation. The present results suggested that miR-29ab1 is essential for diabetic wound healing by regulating the inflammatory response. Suppression of miR-29ab1 by the C@P hydrogel has the potential for improving medical approaches for wound repair.

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A chitosan based hydrogel containing puerarin was constructed for promoting diabetic wound healing.

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Chitosan@Puerarin hydrogel accelerated skin repair through inhibiting M1-polarization and reducing IL-1β and TNF-α.

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miR-29 a/b1 was found to be ectopic increased in the skin-wound of diabetic model.

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miR-29 a/b1 was inhibited by Chitosan@Puerarin in diabetic wound healing.

Investigation of nickel sulfate-induced cytotoxicity and underlying toxicological mechanisms in human umbilical vein endothelial cells through oxidative stress, inflammation, apoptosis, and MAPK signaling pathways

Growing evidence indicates that nickle and its compounds have adverse effects on the cardiovascular system. In this study, the cytotoxic insults caused by nickel sulfate (NiSO₄ ) in human umbilical vein endothelial cells (HUVECs) were explored by examining cell viability, oxidative stress, inflammation, apoptosis, and MAPK signaling pathway activity. Cultured HUVECs were treated with varying concentrations of NiSO₄ (0, 62.5, 250, and 1000 μM) for 24 h. Subsequently, markers of oxidative stress, inflammation, apoptosis, and MAPK signaling pathways were analyzed using biochemical assays, real-time quantitative polymerase chain reaction, and western blot. Rates of apoptosis were evaluated using flow cytometry. The results showed that NiSO₄ exerted dose- and time-dependent inhibitory effects on cell growth. It induced oxidative stress and lipid peroxidation by increasing the generation of reactive oxygen species, the oxidized glutathione to reduced glutathione ratio (GSSG/GSH ratio), and malondialdehyde levels. Further, it inhibited superoxide dismutase activity in HUVECs. Flow cytometry analysis results revealed that NiSO₄ (62.5-1000 μM) could induce apoptosis in HUVECs. The protein and gene expressions of cleaved Caspase 3 and Bax were elevated, and those of Bcl-2 and Bcl-XL were reduced after NiSO₄ treatment. Additionally, NiSO₄ triggered inflammation in HUVECs, increasing the protein and mRNA levels of IL-6 and TNF-α and reducing those of TGF-β. Furthermore, western blot findings revealed that NiSO₄ could activate MAPK signaling pathways, upregulating p38, JNK, and ERK1/2 in HUVECs by increasing the levels of p-P38，p-JNK, and p-ERK1/2 in a dose-dependent manner. MAPK pathway inhibitors (10 μM SB203580 and 10 μM SP600125) could attenuate the NiSO₄ -induced increase in apoptosis and inflammation in HUVECs. They could also attenuate the dysregulation of inflammatory factors and related proteins caused by high-dose NiSO₄ exposure. Interestingly, while the MEK inhibitor U0126 (10 μM) enhanced NiSO₄ -induced apoptosis in HUVECs, it reduced cell inflammation. Taken together, these experimental results suggest that NiSO₄ can inhibit cell growth, induce oxidative stress, and trigger subsequent inflammatory responses and apoptosis in HUVECs. These effects may be mediated by the P38 and JNK MAPK stress response pathways.

Puerarin Induces Molecular Details of Ferroptosis-Associated Anti-Inflammatory on RAW264.7 Macrophages

Puerarin is a natural flavonoid with significant anti-inflammatory effects. Recent studies have suggested that ferroptosis may involve puerarin countering inflammation. However, the mechanism of ferroptosis mediated by the anti-inflammatory process of puerarin has not been widely explored. Herein, puerarin at a concentration of 40 μM showed an anti-inflammatory effect on lipopolysaccharide (LPS)-induced macrophages RAW264.7. The analysis of network pharmacology indicated that 51 common targets were enriched in 136 pathways, and most of the pathways were associated with ferroptosis. Subsequently, the analysis of metabolomics obtained 61 differential metabolites that were enriched in 30 metabolic pathways. Furthermore, integrated network pharmacology and metabolomics revealed that puerarin exerted an excellent effect on anti-inflammatory in RAW264.7 via regulating ferroptosis-related arachidonic acid metabolism, tryptophan metabolism, and glutathione metabolism pathways, and metabolites such as 20-hydroxyeicosatetraenoic acid (20-HETE), serotonin, kynurenine, oxidized glutathione (GSSG), gamma-glutamylcysteine and cysteinylglycine were involved. In addition, the possible active binding sites of the potential targeted proteins such as acyl-CoA synthetase long-chain family member 4 (ACSL4), prostaglandin-endoperoxide synthase 2 (PTGS2), arachidonate 15-lipoxygenase (ALOX15) and glutathione peroxidase 4 (GPX4) with puerarin were further revealed by molecular docking. Thus, we suggested that ferroptosis mediated the anti-inflammatory effects of puerarin in macrophages RAW264.7 induced by LPS.

Puerarin: A Potential Therapeutic for SARS-CoV-2 and Hantavirus Co-Infection

Patients with Hantavirus-caused epidemic hemorrhagic fever (EHF) are at risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is currently no validated EHF/SARS-CoV-2 strategy. Several studies have recently shown Puerarin, a natural product, has potent antiviral properties. The goal of present study was to determine the mechanism of puerarin in patients with EHF/COVID-19. We use network pharmacology and bioinformatics to investigate the possible pharmacological targets, bioactivities, and molecular mechanisms of puerarin in the treatment of patients with EHF/SARS-CoV-2. The study investigated the pathogenesis of COVID-19 and EHF and the signaling pathway impacted by puerarin. 68 common genes linked to puerarin and EHF/SARS-CoV-2 were discovered during the investigation. By using protein-protein interaction (PPI) network, we identified RELA, JUN, NF-B1, NF-B2, and FOS as potential therapeutic targets. The bioactivity and signaling pathways of puerarin have also been demonstrated in the treatment of EHF and COVID-19. According to present study, puerarin could reduce excessive immune responses and inflammation through the NF-B, TNF, and HIF-1 signaling pathways. This study explored the potential therapeutic targets and mechanisms of Puerarin in the treatment of EHF/COVID-19.

Dual-spectrum online monitoring of puerarin and total flavonoids contents during the extraction process of Pueraria lobata

In the extraction process of traditional Chinese medicine (TCM), the rapid detection of the active components of TCM plays a vital role. We pioneered the choice of dual-spectrum technology based on near-infrared (NIR) and ultraviolet-visible (UV-Vis) spectra and applied it to the quantitative monitoring of online extraction of puerarin and total flavonoids from Pueraria lobata. An online monitoring system was constructed to fulfill the dual-spectrum online monitoring. The extraction solution flows from a flask into a pipeline under the control of a peristaltic pump, removing the solid residues contained in the solution with filters. When the extraction solution flows into the cuvette, it will be measured with NIR and UV-Vis portable spectrometers. After finishing the spectra collection, the peristaltic pump will reverse to push the extraction solution back to the flask. The partial least squares (PLS) models were established to quantitatively analyze puerarin and total flavonoids by NIR, UV-Vis, and dual-spectrum data. As for NIR, UV-Vis and dual-spectrum, the RMSEP (mg/mL) of the puerarin models were 0.0803, 0.0500, and 0.0351, and those of the total flavonoids models were 0.4373, 0.2402, and 0.1795, respectively. The results show that the dual-spectrum online monitoring system is simple, stable and fast (a few seconds) in operation, and accurate in prediction. Compared with individual NIR or UV-Vis spectra, the dual-spectra contains more comprehensive information, and the prediction ability is stronger. This method is expected to become a promising tool for the quantitative analysis of other traditional Chinese medicines.

Silk protein/polyvinylpyrrolidone nanofiber membranes loaded with puerarin accelerate wound healing in mice by reducing the inflammatory response

In modern clinical applications, wound healing remains a considerable challenge. Excessive inflammatory response is associated with delayed wound healing. In this study, we prepared composite nanofibrous membranes by mixing the Chinese herbal extract puerarin (PUE) with natural silk protein (SF) and synthetic polymer polyvinylpyrrolidone (PVP) using electrostatic spinning technique, and conducted a series of studies on the structural and biological properties of the fibrous membranes. The results showed that the loading of PUE increased the diameter, porosity and hydrophilicity of nanofibers, which were more favorable for cell adhesion and proliferation. ABTS radical scavenging assay also showed that the loading of PUE enhanced the antioxidant properties of the fibrous membranes. In addition, SF/PVP/PUE nanofibers are non-toxic and can be used as wound dressings. In vitro experiments showed that SF/PVP/PUE nanofibers could effectively alleviate lipopolysaccharide (LPS)-induced inflammation in Immortalized human keratinocytes (HaCaT) cells and down-regulate pro-inflammatory cytokine expression in cells. In vivo studies further showed that the SF/PVP/PUE nanofibers could effectively accelerate wound repair. The mechanism is that SF/PVP/PUE nanofibers can inhibit the activation and transduction of toll-like receptor 4/myeloid differentiation factor88/nuclear factor kappa B (TLR4/MyD88/NF-κB) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathways, thereby reducing the inflammatory response and achieving wound healing.

Protective effect of isoflavones and triterpenoid saponins from pueraria lobata on liver diseases: A review

In recent years, with the improvement of people's living standard and the change of diet structure, liver disease and its related complications have become a significant public health problem globally. Pueraria lobata (Pueraria montana var. lobata (Willd.) Sanjappa & Pradeep) belongs to the genus Pueraria, which is widely planted and used as medicine and food in Asia with a long history. A variety of natural active products, including puerarin, daidzein, formononetin, genistein, and soyasaponin, have been isolated and identified from pueraria lobata. A large number of studies have shown that various natural active products of pueraria lobata can play a protective role in different types of liver diseases by regulating oxidative stress, inflammatory response, lipid metabolism, etc. In this review, we focused on the protective effects of isoflavones and triterpenoid saponins from pueraria lobata on the liver through different targeted therapeutic mechanisms. What's more, we summarized their therapeutic potential for different types of liver diseases to provide evidence for their clinical application.

Nano-selenium attenuates mitochondrial-associated apoptosis via the PI3K/AKT pathway in nickel-induced hepatotoxicity in vivo and in vitro

The aim of this study was to investigate the protective effects of Nano-Se against nickel (Ni)-induced hepatotoxicity and the potential mechanism. Hence, we constructed in vivo and in vitro models of Ni-induced hepatotoxicity. Sprague-Dawley (SD) rats were exposed to nickel sulfate (NiSO₄ , 5.0 mg/kg, i.p.) with or without Nano-Se (0.5, 1, and 2 mg/kg, oral gavage) co-administration for 14 days, and HepG2 cells were exposed to NiSO₄ (1500 μM) with or without Nano-Se (20 μM) for 24 h. Nano-Se obviously prevented Ni-induced hepatotoxicity indicated by ameliorating pathological change and decreasing Ni accumulation in rat livers. Ni induced a significant increase in hepatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSH-Px), and malondialdehyde (MDA) level, decreased the glutathione (GSH) content while compared to those in the control group. Nano-Se administration improved the hepatic antioxidant capacity through increase hepatic GSH contents and GSH-Px activity, decrease the activities of SOD, CAT, and MDA level. Nano-Se improved the cell viability, decreased active oxygen (ROS) generation and ameliorated morphological changes of nuclear structures in Ni-treated HepG2 cells. In addition, Nano-Se inhibited the Ni-induced increases of cytochrome c, caspase-9, cleaved caspase-3, increased PI3K and AKT phosphorylation both in vivo and in vitro. Besides, the PI3K inhibitor Y294002 could inhibit the protective effects of Nano-Se on apoptosis. Thus, Nano-Se significantly activates PI3K/AKT signaling to ameliorate apoptosis in Ni-induced hepatotoxicity.

Mitochondria damage and ferroptosis involved in Ni-induced hepatotoxicity in mice

Nickel (Ni) is an environmental toxicant that can cause toxic damage to humans and animals. Although the hepatotoxicity of Ni has been confirmed, its precise mechanism is still unclear. In this study, the results showed that nickel chloride (NiCl₂)-treatment could induce mice hepatotoxicity including hepatic histopathological alterations and up-regulation of serum AST and ALT. According to the results, NiCl₂ increased malondialdehyde (MDA) production while reducing total antioxidant capacity (T-AOC) activity and glutathione (GSH) content. Additionally, NiCl₂ induced mitochondrial damage which was featured by increase in mitochondrial ROS (mt-ROS) and mitochondrial membrane potential (MMP) depolarization. The mitochondrial respiratory chain complexes I-IV and ATP content were decreased in the liver of NiCl₂-treated mice. Meanwhile, NiCl₂ caused hepatic ferroptosis accompanied by increased iron content in the liver and up-regulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, down-regulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1) and nuclear receptor coactivator 4 (NCOA4) protein and mRNA expression levels. Altogether, the above mentioned results indicate that NiCl₂ treatment may induce hepatic damage through mitochondrial damage and ferroptosis.

Potential Effects of Dietary Isoflavones on Drug-Induced Liver Injury

Numerous prescribed drugs and herbal and dietary supplements have been reported to cause drug-induced acute liver injury, which is a frequent cause of acute liver failure (ALF). It is a tremendous challenge with ever-increasing drug application in the medication system for huge populations. Drug-induced acute liver injury can lead to diverse pathologies similar to acute and chronic hepatitis, acute liver failure, biliary obstruction, fatty liver disease, and so on. Recently, extensive work demonstrated that isoflavones play an essential and protecting role in drug-induced liver injury (DILI). The isoflavones mediated hepatoprotection by modulating specific genes linked with control of cellular redox homeostasis and inflammatory responses. Isoflavones upregulate oxidative stress-responsive nuclear factor erythroid 2-like 2 (Nrf2), downregulate inflammatory nuclear factor-κB (NF-κB) signaling pathways, and modulate a balance between cell survival and death. Moreover, isoflavones actively inhibit the expression of cytochromes P450 (CYPs) enzyme during drug metabolism. Moreover, isoflavones are also linked with farnesoid X receptor (FXR) activation and signal transducer and activator of transcription factor 3 (STAT3) phosphorylation in hepatoprotection DILI. In vivo and in vitro studies clearly stated that isoflavones bear strong antioxidant potential and promising agents for hepatotoxicity prevention and stressed their potential role as therapeutic supplements in DILI. The current review will elaborate on isoflavones’ preventive and therapeutic potential concisely and highlight various molecular targets to exert a protective effect on DILI.

Puerarin attenuates intracerebral hemorrhage-induced early brain injury possibly by PI3K/Akt signal activation-mediated suppression of NF-κB pathway

Intracerebral hemorrhage (ICH) can induce intensively oxidative stress, neuroinflammation, and brain cell apoptosis. However, currently, there is no highly effective treatment available. Puerarin (PUE) possesses excellent neuroprotective effects by suppressing the NF‐κB pathway and activating the PI3K/Akt signal, but its role and related mechanisms in ICH‐induced early brain injury (EBI) remain unclear. In this study, we intended to observe the effects of PUE and molecular mechanisms on ICH‐induced EBI. ICH was induced in rats by collagenase IV injection. PUE was intraperitoneally administrated alone or with simultaneously intracerebroventricular injection of LY294002 (a specific inhibitor of the PI3K/Akt signal). Neurological deficiency, histological impairment, brain edema, hematoma volume, blood–brain barrier destruction, and brain cell apoptosis were evaluated. Western blot, immunohistochemistry staining, reactive oxygen species (ROS) measurement, and enzyme‐linked immunosorbent assay were performed. PUE administration at 50 mg/kg and 100 mg/kg could significantly reduce ICH‐induced neurological deficits and EBI. Moreover, PUE could notably restrain ICH‐induced upregulation of the NF‐κB pathway, pro‐inflammatory cytokines, ROS level, and apoptotic pathway and activate the PI3K/Akt signal. However, LY294002 delivery could efficaciously weaken these neuroprotective effects of PUE. Overall, PUE could attenuate ICH‐induced behavioral defects and EBI possibly by PI3K/Akt signal stimulation‐mediated inhibition of the NF‐κB pathway, and this made PUE a potential candidate as a promising therapeutic option for ICH‐induced EBI.

Puerarin Restores Autophagosome-Lysosome Fusion to Alleviate Cadmium-Induced Autophagy Blockade via Restoring the Expression of Rab7 in Hepatocytes

Autophagic dysfunction is one of the main mechanisms by which the environmental pollutant cadmium (Cd) induces cell injury. Puerarin (Pue, a monomeric Chinese herbal medicine extract) has been reported to alleviate Cd-induced cell injury by regulating autophagy pathways; however, its detailed mechanisms are unclear. In the present study, to investigate the detailed mechanisms by which Pue targets autophagy to alleviate Cd hepatotoxicity, alpha mouse liver 12 (AML12) cells were used to construct a model of Cd-induced hepatocyte injury in vitro. First, the protective effect of Pue on Cd-induced cell injury was confirmed by changes in cell proliferation, cell morphology, and cell ultrastructure. Next, we found that Pue activated autophagy and mitigated Cd-induced autophagy blockade. In this process, the lysosome was further activated and the lysosomal degradation capacity was strengthened. We also found that Pue restored the autophagosome-lysosome fusion and the expression of Rab7 in Cd-exposed hepatocytes. However, the fusion of autophagosomes with lysosomes and autophagic flux were inhibited after knocking down Rab7, and were further inhibited after combined treatment with Cd. In addition, after knocking down Rab7, the protective effects of Pue on restoring autophagosome-lysosome fusion and alleviating autophagy blockade in Cd-exposed cells were inhibited. In conclusion, Pue-mediated alleviation of Cd-induced hepatocyte injury was related to the activation of autophagy and the alleviation of autophagy blockade. Pue also restored the fusion of autophagosomes and lysosomes by restoring the protein expression of Rab7, thereby alleviating Cd-induced autophagy blockade in hepatocytes.

Ethanol extract of Nigella sativa has antioxidant and ameliorative effect against nickel chloride-induced hepato-renal injury in rats

Background

Nickel exposure causes hepato-renal toxicity via oxidative stress. Medicinal plants with antioxidants properties are being explored as treatment options. In this study, the effect of ethanol extract of Nigella sativa (ENS) on nickel chloride (NiCl2)-induced hepato-renal damage was evaluated by monitoring biochemical and oxidative stress markers. Additionally, the antioxidant capacity and phytochemical constituents of ENS were quantified using HPLC and GC-MS.

Result

NiCl2 significantly increased (p < 0.05) aspartate aminotransferase, creatinine, sodium ion, chloride ion and malondialdehyde levels, while antioxidant enzymes were decreased in the organs except for kidney glutathione-S-transferase when compared to the control. However, ENS exerted inhibitory effect against NiCl2 toxicity in both organs by reversing the biomarkers towards control levels. ENS has a high antioxidant capacity and is rich in antioxidants including gallic acid, quercetin, eucalyptol and levomenthol that may have accounted for the improvement of hepato-renal health in co-exposed rats.

Conclusion

Our result suggests that amelioration of nickel chloride-induced hepato-renal pathology by ethanol extract of Nigella sativa was related to its antioxidant properties. Therefore, Nigella sativa could be valuable in the management of nickel-induced toxicity.

Protective effect of puerarin against burn-induced heart injury in rats

The present study evaluated the potential protective effects of puerarin and its associated mechanism on burn-induced myocardial damage. A total of 40 healthy adult Wistar rats were randomly divided into four groups: i) Sham; ii) burn; iii) burn + puerarin; and iv) puerarin. Serum levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) and IL-6 were measured using ELISA. Myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels were determined in myocardial homogenates using a commercial assay kit. TUNEL staining and western blot analysis of cleaved and pro-caspase-3 were also performed to assess apoptosis. Activation of p38-MAPK, ERK, JNK and AKT were measured using western blot analysis. Left ventricular systolic pressure, maximum rates of increase/decrease in left ventricular pressure, creatine kinase MB activity and cardiac troponin T levels were found to be altered in the burn group 12 h after burn, which were reversed by puerarin treatment. Injection of puerarin following burn injury also reduced heart water content. Serum levels of IL-1β, TNF-α and IL-6 were significantly higher in the burn group compared with those in the sham group. Puerarin treatment reduced serum levels of IL-1β, TNF-α and IL-6, in addition to reducing MPO activity and MDA levels in myocardial tissues. Puerarin inhibited the activation of caspase-3, p38, ERK and JNK following severe burn, but elevated Akt activation following severe burn. In conclusion, puerarin improved cardiac function in rats following severe burn injury, which may be due to reduced myocardial injury, inhibition of cardiomyocyte apoptosis and reduced oxidative inflammatory stress; the MAPK and AKT signaling pathways are proposed to the underlying mechanism of these findings.

Simultaneous quantitation of glycyrrhetic acid and puerarin in plasma using ultra flow liquid chromatography tandem mass spectrometry and application in a pharmacokinetics study in healthy and alcoholic liver injury rats

A rapid, sensitive, and accurate ultra flow liquid chromatography tandem mass spectrometry (UFLC-MS/MS ) method was developed and validated for simultaneous quantitation of glycyrrhetic acid and puerarin in plasma derived from healthy and alcoholic liver injury rats. Plasma samples from healthy and model rats were deproteinated with methanol using liquiritin as an internal standard. Chromatography separation was performed by a Waters BEH (ethylene-bridged hybrid) C₁₈ column (2.1 × 50 mm; 1.7 μm) using a gradient elution from acetonitrile and water (containing 0.1% formic acid) and at a flow rate of 0.4 mL/min. Quantitation was performed on a Triple Quad 4500 tandem mass spectrometer coupled with an electrospray ionization source in negative multiple reaction monitoring mode. Specificity, carryover, dilution integrity, recovery, linearity, precision and accuracy, matrix effect, and stability were within acceptable limits. The newly established method was successfully applied to a pharmacokinetics study to investigate glycyrrhetic acid and puerarin in healthy and alcoholic liver injury rats.

Impact of binary waterborne mixtures of nickel and zinc on hypothalamic-pituitary-testicular axis in rats

Several evidences from the literature showed that the coexistence of nickel and zinc in polluted waters is related to the similarity in their geogenic and anthropogenic factors. Although most environmental exposures to metals do not occur singly, there is a paucity of scientific knowledge on the effects of zinc and nickel co-exposure on mammalian reproductive health. The present study investigated the influence of co-exposure to nickel and zinc on male reproductive function in rats. Experimental rats were co-exposed to environmentally relevant concentrations of waterborne nickel (75 and 150 μg NiCl₂ L^-1) and zinc (100 and 200 μg ZnCl₂ L^-1) for 45 successive days. Subsequently, reproductive hormones were assayed whereas the hypothalamus, epididymis and testes of the rats were processed for the assessment of oxidative stress and inflammation indices, caspase-3 activity and histology. Results indicated that co-exposure to nickel and zinc significantly (p < 0.05) abolished nickel-mediated diminution of antioxidant defense mechanisms while diminishing levels of reactive oxygen and nitrogen species and lipid peroxidation in the hypothalamus, epididymis and testes of the exposed rats. Additionally, co-exposure to zinc abated nickel-mediated diminutions in luteinizing hormone, follicle-stimulating hormone, serum and intra-testicular testosterone with concomitant enhancement of sperm production and quality. Further, zinc abrogated nickel-mediated elevation in inflammatory biomarkers including nitric oxide, tumor necrosis factor alpha, interleukin-1 beta as well as caspase-3 activity. The protective influence of zinc on nicked-induced reproductive toxicity was well supported by histological data. Overall, zinc ameliorated nickel-induced reproductive dysfunction via its anti-oxidant, anti-inflammatory, anti-apoptotic and spermato-protective activities in rats.

Impact of Heavy Metals on Host Cells: Special Focus on Nickel-Mediated Pathologies and Novel Interventional Approaches

BACKGROUND

Heavy metals [arsenic, aluminium, cadmium, chromium, cobalt, lead, nickel (Ni), palladium and titanium] are environmental contaminants able to impact with host human cells, thus, leading to severe damage.

OBJECTIVE

In this review, the detrimental effects of several heavy metals on human organs will be discussed and special emphasis will be placed on Ni. In particular, Ni is able to interact with Toll-like receptor-4 on immune and non-immune cells, thus, triggering the cascade of pro-inflammatory cytokines. Then, inflammatory and allergic reactions mediated by Ni will be illustrated within different organs, even including the central nervous system, airways and the gastrointestinal system.

DISCUSSION

Different therapeutic strategies have been adopted to mitigate Ni-induced inflammatoryallergic reactions. In this context, the ability of polyphenols to counteract the inflammatory pathway induced by Ni on peripheral blood leukocytes from Ni-sensitized patients will be outlined. In particular, polyphenols are able to decrease serum levels of interleukin (IL)-17, while increasing levels of IL- 10. These data suggest that the equilibrium between T regulatory cells and T helper 17 cells is recovered with IL-10 acting as an anti-inflammatory cytokine. In the same context, polyphenols reduced elevated serum levels of nitric oxide, thus, expressing their anti-oxidant potential. Finally, the carcinogenic potential of heavy metals, even including Ni, will be highlighted.

CONCLUSION

Heavy metals, particularly Ni, are spread in the environment. Nutritional approaches seem to represent a novel option in the treatment of Ni-induced damage and, among them, polyphenols should be taken into consideration for their anti-oxidant and anti-inflammatory activities.

Sargassum hystrix as a Source of Functional Food to Improve Blood Biochemistry Profiles of Rats under Stress

This study was conducted to determine the influence of Sargassum hystrix powder (SHP) as an alternative source of functional food for treating in vivo stress by measuring levels of glucose, triacylglycerol, total cholesterol, and cortisol, and liver histopathology. Wistar rats aged 3 months and weighing 150~200 g were divided into 7 groups: normal control, fasting control, negative control (stress without adaptogen), and 4 experimental conditions (stress+0.18 mg/kg diazepam, stress+450 mg/kg pellet, stress+mixture of pellet with SHP 450 mg/kg, and stress+450 mg/kg of SHP). Intake of liquids and and body weight were measured daily. Blood samples were collected on day 0 (baseline), day 5, and day 10 to analyze levels of glucose, triacylglycerol, cholesterol, and cortisol. On day 10, rats were euthanized and livers were collected to observe the severity of inflammation. The results indicated that rats receiving SHP 450 mg/kg and the mixture of pellet with SHP 450 mg/kg showed a similar ability as those receiving diazepam 0.18 mg/kg to cope with stress, indicated by an improvement in all blood biochemistry parameters. Supplementation with SHP 450 mg/kg can be used as an alternative source of functional food for overcoming oxidative stress, as indicated by its ability to improve levels of blood glucose, triacylglycerol, total cholesterol, and cortisol, and to improve liver histology by decreasing severity of liver inflammation.

Puerarin prevents cataract development and progression in diabetic rats through Nrf2/HO‑1 signaling

Puerarin is the major bioactive ingredient isolated from the dry root of Pueraria lobata, a plant used in traditional Chinese medicine. Puerarin has been used to treat diabetes and cataracts in China; however, its underlying mechanism of action remains unclear. The aim of the present study was to investigate the effectiveness and mechanism of puerarin in preventing cataracts in diabetic rats. Diabetes was induced by streptozocin (STZ) administration and rats were intraperitoneally injected with puerarin (25, 50 and 100 mg/kg). Blood glucose levels and cataract development were examined in the different experimental groups. In addition, the expression levels of markers associated with oxidative stress, including nuclear factor erythroid 2 like 2 (Nrf2) and heme oxygenase‑1 (HO‑1), were analyzed. The present results suggested that treatment with puerarin at 25, 50 and 100 mg/kg significantly reduced blood glucose levels and the incidence of cataract in STZ‑induced diabetic rats. Additionally, puerarin treatment reduced oxidative stress, restoring the levels of malondialdehyde and glutathione, and the activity of glutathione peroxidase. Furthermore, puerarin administration decreased the expression levels of retinal vascular endothelial growth factor and interleukin‑1β and increased the mRNA expression levels of Nrf2 and HO‑1, thus inhibiting oxidative stress. The present findings suggested that puerarin had hypoglycemic effects and that it prevented cataract development and progression in diabetic rats by reducing oxidative stress through the Nrf2/HO‑1 signaling pathway.

Puerarin prevents cadmium-induced hepatic cell damage by suppressing apoptosis and restoring autophagic flux

Cadmium (Cd) is a common heavy metal contamination that is highly toxic to liver. Puerarin (PU), a potent free radical scavenger, has been shown to exert cytoprotective effect in numerous pathological processes. However, whether PU affords protection against Cd-induced hepatotoxicity remains unclear to be known. Here, we aimed to investigate the protective effect of PU on Cd-induced hepatotoxicity in an immortalized mouse hepatocyte line, AML-12. First, Cd-induced cytotoxicity in AML-12 cells was obviously ameliorated by PU treatment. Also, Cd-induced apoptotic cell death was markedly alleviated by PU treatment, evidenced by two methods. Simultaneously, Cd-elevated malondialdehyde and reactive oxygen species levels were significantly reduced by PU administration, demonstrating the antioxidant effect of PU against Cd exposure. Moreover, Cd-induced blockage of autophagic flux in AML-12 cells was obviously restored by PU treatment, evidenced by immunoblot analysis of autophagy marker proteins and tandem fluorescent-tagged LC3 method. Resultantly, Cd-induced autophagosome accumulation was significantly alleviated by PU treatment. In conclusion, these observations demonstrate that PU treatment alleviates Cd-induced hepatic cell damage by inhibiting apoptosis and restoring autophagy activity, which is intimately related with its antioxidant activity.

Puerariae Lobatae Radix with chuanxiong Rhizoma for treatment of cerebral ischemic stroke by remodeling gut microbiota to regulate the brain-gut barriers

The combination of Puerariae Lobatae Radix (PLR) and Chuanxiong Rhizoma (CXR) is commonly used to treat cerebrovascular diseases. This work aimed to clarify the mechanisms of their action in treating cerebral ischemic stroke from the perspective of gut microecology. The PLR and CXR combination effectively improved the neurological function, reduced the cerebral infarction and relieved the complications of cerebral ischemic stroke, including dyslipidemia, increased blood viscosity and thrombotic risk. Cerebral ischemic stroke triggered gut microbial disturbances by enriching pathogens and opportunistic microorganisms, including Bacteroides, Escherichia_Shigella, Haemophilus, Eubacterium_nodatum_group, Collinsella, Enterococcus, Proteus, Alistipes, Klebsiella, Shuttleworthia and Faecalibacterium. Cerebral ischemic stroke also increased the intestinal permeability, disrupted the gut barrier and caused intestinal microbial translocation. Occludin, claudin-5 and ZO-1 levels in the brain-gut barriers showed a high positive correlation. However, the combination remodeled the gut microecology by modulating endogenous bacteria whose effects may mitigate cerebral damage, such as Alloprevotella, Ruminococcaceae, Oscillospira, Lachnospiraceae_NK4B4_group, Akkermansia and Megasphaera, protected the brain-gut barriers by increasing claudin-5 and ZO-1 levels; and weakened the gut microbiota translocation by decreasing diamine oxidase, lipopolysaccharide and d-lactate. Although nimodipine effectively reduced the cerebral infarction, it did not relieve the gut microbiota dysbiosis and instead aggravated the gut barrier disruption and microbiota translocation. In conclusion, cerebral ischemic stroke caused gut microbiota dysbiosis, increased intestinal permeability, disrupted the gut barrier and triggered gut microbiota translocation. The PLR and CXR combination was an effective treatment for cerebral ischemic stroke that relieved the gut microbiota dysbiosis and brain-gut barriers disruption.

Effect of Puerarin Regulated mTOR Signaling Pathway in Experimental Liver Injury

It is known that excessive hepatocellular apoptosis is a typical characteristic of hepatic disease, and is regulated by the mammalian target of rapamycin (mTOR) signaling pathway. As the main active component of Kudzu (Pueraria lobata) roots, which is frequently used to treat hepatic diseases, Puerarin (Pue) has been reported to alleviate and protect against hepatic injury. However, it is unclear whether Pue can inhibit mTOR signaling to prevent excessive apoptosis in the treatment of hepatic diseases. In the present study, Pue effectively ameliorated pathological injury of the liver, decreased serum enzyme (ALT, AST, γ-GT, AKP, DBIL, and TBIL) levels, regulated the balance between pro-inflammatory (TNF-α, IL-1β, IL-4, IL-6, and TGF-β1) and anti-inflammatory cytokines (IL-10), restored the cell cycle and inhibited hepatocellular apoptosis and caspase-3 expression in rats with liver injury induced by 2-AAF/PH. Pue inhibited p-mTOR, p-AKT and Raptor activity, and increased Rictor expression in the liver tissues of rats with experimental liver injury. These results indicated that Pue effectively regulated the activation of mTOR signaling pathway in the therapeutic and prophylactic process of Pue on experimental liver injury.

Role of oxidative stress in liver toxicity induced by nickel oxide nanoparticles in rats

The aim of the present study was to explore the role of oxidative stress in liver toxicity induced by nickel oxide nanoparticles (nano‑NiO) in rats. Male Wistar rats received saline (control), nano‑NiO [0.015, 0.06 or 0.24 mg/kg body weight (b.w.)] or micro‑NiO (0.24 mg/kg b.w.) by intratracheal instilling twice a week for 6 weeks. Liver tissues were then collected and examined for biomarkers of nitrative and oxidative stress, as well as mRNA expression of heme oxygenase (HO)‑1 and metallothionein (MT)‑1. The results demonstrated that the NiO exposure groups had increased liver wet weight and coefficient to body weight, as well as liver pathological changes, evidenced as cellular edema, hepatic sinus disappeara-nce and binucleated hepatocytes. The activities of total nitric oxide synthase and inducible nitric oxide synthase, and the nitric oxide content, were increased in the 0.24 mg/kg nano‑NiO group compared with the control group. The MT‑1 mRNA expression levels were downregulated, while HO‑1 mRNA was upregulated in the 0.24 mg/kg nano‑NiO exposure group compared with the control group. In addition, abnormal changes of hydroxyl radical, lipid peroxidation, catalase, glutathione peroxidase, total superoxide dismutase and total antioxidative capacity were observed in the liver tissues of the 0.24 mg/kg nano‑NiO exposure group, compared with the control group. The present results therefore indicated that nano‑NiO‑induced liver toxicity may be associated with nitrative and oxidative stress in rats.

Glutaredoxin 1 (GRX1) inhibits oxidative stress and apoptosis of chondrocytes by regulating CREB/HO-1 in osteoarthritis

GRX1 (glutaredoxin1), a sulfhydryl disulfide oxidoreductase, is involved in many cellular processes, including anti-oxidation, anti-apoptosis, and regulation of cell differentiation. However, the role of GRX1 in the oxidative stress and apoptosis of osteoarthritis chondrocytes remains unclear, prompting the current study. Protein and mRNA expressions were measured by Western blot and RT-qPCR. Oxidative stress was detected by the measurement of MDA and SOD contents. Cells apoptosis were detected by Annexin V-FITC/PI and caspase-3 activity assays. We found that the mRNA and protein expressions of GRX1 were significantly down-regulated in osteoarthritis tissues and cells. GRX1 overexpression increased the mRNA and protein expression of CREB and HO-1. Meanwhile, GRX1 overexpression inhibited oxidative stress and apoptosis in osteoarthritis chondrocytes. Furthermore, we found that GRX1 overexpression regulated HO-1 by increasing CREB, and that HO-1 regulated oxidative stress and apoptosis in osteoarthritis chondrocytes. Thus, GRX1 overexpression constrains oxidative stress and apoptosis in osteoarthritis chondrocytes by regulating CREB/HO-1, providing a novel insight into the molecular mechanism and potential treatment of osteoarthritis.

Puerarin Suppresses Macrophage Activation via Antioxidant Mechanisms in a CaPO4-Induced Mouse Model of Aneurysm

Aneurysm is characterized by balloon-like expansion of the arterial wall and eventual rupture of the aorta. The pathogenesis of aneurysm is associated with the degradation of matrix proteins by matrix metalloproteinases (MMPs) produced by activated macrophages. Although aneurysm is associated with significant mortality and morbidity, surgical intervention is the only proven treatment strategy. Therefore, development of therapeutic agents for aneurysm is greatly anticipated. Here, we demonstrated the protective effects of the major isoflavone puerarin, which is found in kudzu roots and vines. Aneurysms were surgically induced in ten-wk-old male mice using CaPO₄. Subsequently, animals were intraperitoneally injected daily with puerarin at 2.5 mg/kg body weight or with vehicle alone for 2 wk. CaPO₄-induced aneurysm was significantly suppressed by puerarin administration. In subsequent macrophage activation assays using Tumor necrosis factor (TNFα) and CaPO₄ crystals in vitro, puerarin decreased Mmp9 mRNA expression and secreted protein levels. Moreover, induction of IκB, ERK, and p38 phosphorylation by TNFα and CaPO₄ in macrophages was suppressed by puerarin treatments. Finally, puerarin attenuated reactive oxygen species production, following induction by TNFα and CaPO₄. Taken together, the present data demonstrate that puerarin suppresses macrophage activation by inhibiting IκB, ERK, and p38 activity and reactive oxygen species production in a CaPO₄-induced mouse model of aneurysm.

Treatment of cardiovascular pathology with epigenetically active agents: Focus on natural and synthetic inhibitors of DNA methylation and histone deacetylation

Cardiovascular disease (CVD) retains a leadership as a major cause of human death worldwide. Although a substantial progress was attained in the development of cardioprotective and vasculoprotective drugs, a search for new efficient therapeutic strategies and promising targets is under way. Modulation of epigenetic CVD mechanisms through administration epigenetically active agents is one of such new approaches. Epigenetic mechanisms involve heritable changes in gene expression that are not linked to the alteration of DNA sequence. Pathogenesis of CVDs is associated with global genome-wide changes in DNA methylation and histone modifications. Epigenetically active compounds that influence activity of epigenetic modulators such as DNA methyltransferases (DNMTs), histone acetyltransferases, histone deacetylases (HDACs), etc. may correct these pathogenic changes in the epigenome and therefore be used for CVD therapy. To date, many epigenetically active natural substances (such as polyphenols and flavonoids) and synthetic compounds such as DNMT inhibitors or HDAC inhibitors are known. Both native and chemical DNMT and HDAC inhibitors possess a wide range of cytoprotective activities such as anti-inflammatory, antioxidant, anti-apoptotic, anti-anfibrotic, and anti-hypertrophic properties, which are beneficial of treatment of a variety of CVDs. However, so far, only synthetic DNMT inhibitors enter clinical trials while synthetic HDAC inhibitors are still under evaluation in preclinical studies. In this review, we consider epigenetic mechanisms such as DNA methylation and histone modifications in cardiovascular pathology and the epigenetics-based therapeutic approaches focused on the implementation of DNMT and HDAC inhibitors.

Puerarin protects against cadmium-induced proximal tubular cell apoptosis by restoring mitochondrial function

Puerarin (PU) is a potent free radical scavenger with a protective effect in nephrotoxin-mediated oxidative damage. Here, we show a novel molecular mechanism by which PU exerts its anti-apoptotic effects in cadmium (Cd)-exposed primary rat proximal tubular (rPT) cells. Morphological assessment and flow cytometric analysis revealed that PU significantly decreased Cd-induced apoptotic cell death of rPT cells. Administration of PU protected cells against Cd-induced depletion of mitochondrial membrane potential (ΔΨm) and lipid peroxidation. Cd-mediated mitochondrial permeability transition pore (MPTP) opening, disruption of mitochondrial ultrastructure, mitochondrial cytochrome c (cyt-c) release, caspase-3 activation and subsequently poly ADP-ribose polymerase (PARP) cleavage could be effectively blocked by the addition of PU. Moreover, up-regulation of Bcl-2 and down-regulation of Bax and hence increased Bcl-2/Bax ratio were observed with the PU administration. In addition, PU reversed Cd-induced ATP depletion by restoring ΔΨm to affect ATP production and by regulating expression levels of ANT-1 and ANT-2 to improve ATP transport. In summary, PU inhibited Cd-induced apoptosis in rPT cells by ameliorating the mitochondrial dysfunction.

Oxidative stress and inflammatory responses involved in dietary nickel chloride (NiCl2)-induced pulmonary toxicity in broiler chickens

The respiratory system is the primary target of nickel or nickel compound toxicity after inhalation exposure. There are no reports on the effects of nickel or nickel compounds on the lung via dietary administration at present. This study aimed to investigate pulmonary toxicity induced by dietary NiCl₂ in broiler chickens by using histopathology, qRT-PCR, and ELISA. In comparison with the control group, NiCl₂ intake induced oxidative damage to DNA (upregulation of 8-OHdG) and lipid peroxidation (upregulation of MDA), which was associated with the upregulation of NO and the downregulation of the expression levels and activities of pulmonary CuZn-SOD, Mn-SOD, CAT, GSH-Px, GR and GST mRNA. Also, the T-AOC activity, GSH content, ability to inhibit the generation of hydroxyl radicals, and ratio of GSH/GSSG were decreased in the groups treated with NiCl₂. Concurrently, the mRNA expression levels of iNOS, TNF-α, COX-2, IL-1β, IL-6, IL-8, IL-18 and IFN-γ were increased via the activation of NF-κB, and the mRNA expression levels of anti-inflammatory mediators including IL-2, IL-4 and IL-13 were decreased in the groups treated with NiCl₂. The above-mentioned results were the first to demonstrate that NiCl₂ intake induced pulmonary oxidative stress and inflammatory responses via the dietary pathway, which subsequently contributed to histopathological lesions and dysfunction.