Preparation methods, structural characteristics, and biological activity of polysaccharides from Platycodon grandiflorus.

Platycodon grandiflorus (P. grandiflorus), a traditional Chinese medicinal herb used for both medicine and food, has a long history of treating respiratory infections, bronchitis, pneumonia, and other lung-related diseases. The therapeutic effects of P. grandiflorus are attributed to its chemical components, including polysaccharides. Among these components, Platycodon grandiflorus polysaccharides (PGP) are recognized as one of the most important and abundant active ingredients, exhibiting various biological activities such as prebiotic, antioxidant, antiviral, anticancer, antiangiogenic, and immune regulatory properties. Incorporating the principles of traditional Chinese medicine, carrier concepts, and modern targeted drug delivery technologies, PGP can influence the target sites and therapeutic effects of other drugs while also serving as a drug carrier for targeted and precise treatments. Therefore, it is essential to provide a comprehensive review of the extraction, separation, purification, physicochemical properties, and biological activities of PGP. In the future, by integrating new concepts, technologies, and processes, further references and guidance can be provided for the comprehensive development of PGP. This will contribute to the advancement of P. grandiflorus in various fields such as pharmaceuticals, health products, and food.

Development and evaluation of serological screening based on one dried plasma spot for HIV, syphilis, and HCV.

BACKGROUND: In the effort to prevent and control HIV/AIDS, China has established a national sentinel surveillance system. However, some sentinel sites face limitations in environmental resources and accessibility, prompting the exploration of alternative sample strategies. Dried plasma spots (DPS) samples are viewed as promising alternatives to traditional plasma samples due to their advantages, including sample stability, easy storage, and convenient transport. This study aims to develop a method for screening HIV, Treponema pallidum (TP), and Hepatitis C Virus (HCV) using DPS samples and assess their performance. METHODS: Based on existing commercial assay kits, a detection method was established through the optimization of experimental parameters, including the amount of plasma on filter paper, the volume of elution solution applied to dried plasma spots, the size of dried plasma spots, elution solution volume, elution solution components, elution temperature, and elution time. A series of laboratory evaluation panels were constructed for laboratory assessments, including the laboratory basic panel, laboratory interference panel, and laboratory precision panel. Additionally, clinical samples were used for evaluation. RESULTS: Optimal conditions for DPS sample extraction were: plasma volume, 100 µL; DPS size, whole spot; eluent volume, 500 µL; eluent, PBS with 1‰ Tween20; elution time, 2 h; elution temperature, room temperature. A total of 619 paired plasma/DPS samples were tested by both methods. The DPS-based ELISA method exhibited 100% sensitivity/specificity for HIV, 98.6%/100% for TP, and 99.6%/100% for HCV. Kappa values between the plasma samples and DPS samples were 100% for HIV, 99% for TP, and 100% for HCV. The DPS-based ELISA method failed to detect 1 HCV mono-infected sample and TP in 1 HIV/HCV/TP co-infected sample. For the HIV/HCV/TP co-infected sample, the S/CO in the plasma sample was 2.143 and in the DPS sample was 0.5. For HCV, the S/CO (sample OD/cut-off) was 3.049 in the plasma sample and 0.878 in the DPS sample. CONCLUSIONS: A single DPS, following one-time standardized processing, can be used to detect HIV, HCV, and TP. Researching and establishing laboratory testing methods better suited for China's sentinel surveillance have significant practical applications in improving HIV testing in resource-constrained environments.

PDCD6 Promotes Hepatocellular Carcinoma Cell Proliferation and Metastasis through the AKT/GSK3ß/ß-catenin Pathway.

Objective: Programmed cell death 6 (PDCD6), a Ca 2+-binding protein, has been reported to be aberrantly expressed in all kinds of tumors. The aim of this study was to explore the role and mechanism of PDCD6 in hepatocellular carcinomas (HCCs). Methods: The expression levels of PDCD6 in liver cancer patients and HCC cell lines were analyzed using bioinformatics and Western blotting. Cell viability and metastasis were determined by methylthiazol tetrazolium (MTT) and transwell assays, respectively. And Western blotting was used to test related biomarkers and molecular pathway factors in HCC cell lines. LY294002, a PI3K inhibitor inhibiting AKT, was used to suppress the AKT/GSK3ß/ß-catenin pathway to help evaluate the role of this pathway in the HCC carcinogenesis associated with PDCD6. Results: The analysis of The Cancer Genome Atlas Database suggested that high PDCD6 expression levels were relevant to liver cancer progression. This was consistent with our finding of higher levels of PDCD6 expression in HCC cell lines than in normal hepatocyte cell lines. The results of MTT, transwell migration, and Western blotting assays revealed that overexpression of PDCD6 positively regulated HCC cell proliferation, migration, and invasion. Conversely, the upregulation of PDCD6 expression in the presence of an AKT inhibitor inhibited HCC cell proliferation, migration, and invasion. In addition, PDCD6 promoted HCC cell migration and invasion by epithelial-mesenchymal transition. The mechanistic investigation proved that PDCD6 acted as a tumor promoter in HCC through the AKT/GSK3ß/ß-catenin pathway, increasing the expression of transcription factors and cellular proliferation and metastasis. Conclusion: PDCD6 has a tumor stimulative role in HCC mediated by AKT/GSK3ß/ß-catenin signaling and might be a potential target for HCC progression.

Phytochemicals, Biological Activities, Molecular Mechanisms, and Future Prospects of Plantago asiatica L.

Plantago asiatica L. has been used as a vegetable and nutritious food in Asia for thousands of years. According to recent phytochemical and pharmacological research, the active compositions of the plant contribute to various health benefits, such as antioxidant, anti-inflammatory, antibacterial, antiviral, and anticancer. This article reviews the 87 components of the plant and their structures, as well as their biological activities and molecular research progress, in detail. This review provides valuable reference material for further study, production, and application of P. asiatica, as well as its components in functional foods and therapeutic agents.

Anti-oxidant, anti-inflammatory and anti-fibrosis effects of ganoderic acid A on carbon tetrachloride induced nephrotoxicity by regulating the Trx/TrxR and JAK/ROCK pathway.

Ganoderic acid A (GAA), one of the major triterpenoid components extracted from Ganoderma mushroom has been shown to possess numerous important pharmacological activities. The present study was aimed to investigate the mechanisms of GAA on carbon tetrachloride (CCl4)-induced kidney inflammation, fibrosis and oxidative stress in mice. The male mice were treated with 25 and 50 mg/mg GAA after stimulated with CCl4. Our results showed that GAA improved renal damage by decreasing the serum levels of creatinine, urea, uric acid and alleviating kidney fibrosis. GAA ameliorated CCl4-induced indices of inflammation. GAA suppressed oxidative stress by regulating the glutathione antioxidant system and the thioredoxin antioxidant system. GAA increased the activations of thioredoxin reductase (TrxR), Trx, GSH, SOD, GPx. Furthermore, GAA supplementation inhibited the JAK and STAT3 pathway. GAA inhibited the activations of RhoA, ROCK, NF-κB, TGF-ß and Smad3. Thus, this study demonstrated that GAA possesses immune-protective properties through regulating the Trx/TrxR, JAK2/STAT3 and RhoA/ROCK pathways.

Exploration of an Efficient Simultaneous Molecular Detection Method of HIV, HCV, and Syphilis from a Single Dried Blood Spot.

OBJECTIVE: The aim of the present study was to evaluate the performance of the simultaneous detection of HIV-1 RNA, HIV-1 DNA, and HCV RNA using one dried blood spot (DBS) as an alternative sample to plasma. METHOD: A total of 571 paired DBS/plasma samples were collected from men who have sex with men (MSM) and injection drug users (IDUs), and serological and molecular assays were performed. Using plasma results as the reference standard, the performance of DBS tests for HIV-1 RNA, HIV-1 DNA, and HCV RNA was evaluated. Pearson's correlation coefficients and Bland-Altman analysis were performed to assess the correlation and concordance between DBS and plasma. RESULTS: Among paired plasma/DBS samples with detectable HIV-1 RNA and HCV RNA, five samples (5/32) were not detectable in DBS, while measurable HIV-1 RNA levels were present in plasma (1.44 to 3.99 log 10 copies/mL). There were two samples (2/94) with undetectable HCV RNA in DBS, while measurable HCV RNA levels were present in plasma (-5 to 5.99 log 10 copies/mL). The correlation between HIV-1 RNA light chain variable region (VL) values obtained from plasma and DBS showed that r = 0.683 ( P < 0.01), n = 27 and r = 0.612 ( P < 0.01), n = 89 in HCV RNA. Bland-Altman analysis revealed that in HIV-1 RNA, the mean (± SD) difference between HIV-1 RNA in plasma and DBS was 1.00 ± 1.01 log 10 copies/mL, and all samples were within ± 1.96 SD (-0.97 to 2.97 log 10 copies/mL) for DBS. The mean difference (± SD) in HCV RNA was 0.15 ± 1.08 log 10 copies/mL, and 94.38% (84/89) were within ± 1.96 SD (-1.96 to 2.67 log 10 copies/mL). Overall, HIV-1 RNA and HCV RNA levels obtained from a DBS were lower than those obtained from plasma. HIV-1 DNA in a DBS showed concordant results with HIV-1 RNA in plasma. HIV-1 DNA RT-PCR using a DBS showed acceptable performance. CONCLUSION: The performance of the simultaneous detection of HIV-1 RNA, HIV-1 DNA, and HCV RNA using one DBS was acceptable. DBS, as an alternative sample to plasma, may be a viable option for the simultaneous detection of HIV-1 RNA, HIV-1 DNA, and HCV RNA in resource-limited settings or for individuals living in areas that are difficult to access.

Bixin attenuates carbon tetrachloride induced oxidative stress, inflammation and fibrosis in kidney by regulating the Nrf2/TLR4/MyD88 and PPAR-γ/TGF-ß1/Smad3 pathway.

Bixin, an natural carotenoid extracted from the seeds of the Bixa orellana has been shown to possess numerous important pharmacological activities. The present study was aimed to investigate the mechanisms of Bixin on carbon tetrachloride (CCl4)-induced kidney inflammation, fibrosis and oxidative stress in mice. Our results showed that Bixin improved renal damage by decreasing the serum levels of creatinine, urea, uric acid and alleviating kidney fibrosis. Bixin ameliorated CCl4-induced inflammation in kidneys by reducing the levels of TNF-α and IL-1ß. Bixin suppressed oxidative stress by decreasing the MDA level and increasing the activation of SOD, CAT and GPx. Furthermore, Bixin increased the levels of PPAR-γ, NQO1, HO-1 and the nuclear translocation of Nrf2 in the kidneys of mice. Bixin supplementation inhibited the activation of TLR4, MyD88, NF-κB, TGF-ß and Smad3. Thus, this study demonstrated that Bixin possesses anti-oxidant, anti-inflammatory and anti-fibrosis properties through regulating the Nrf2/TLR4/MyD88 and PPAR-γ/TGF-ß1/Smad3 pathways.

Effects of Gastrodin against Lead-Induced Brain Injury in Mice Associated with the Wnt/Nrf2 Pathway.

Gastrodin (GAS), the main phenolic glycoside extracted from Gastrodia elata Blume, exhibited potential neuroprotective properties. Here we examined the protective effects of GAS against lead(Pb)-induced nerve injury in mice, and explores its underlying mechanisms. Our research findings revealed that GAS improved behavioral deficits in Pb-exposed mice. GAS reduced the accumulation of p-tau and amyloid-beta (Aß). GAS inhibited Pb-induced inflammation in the brain, as indicated by the decreased levels of pro-inflammatory cytokines, including tumor necrosis factor-a (TNF-α), cyclooxygenase-2 (COX-2). GAS increased the expression levels of NR2A and neurotrophin brain-derived neurotrophic factor (BDNF). GAS inhibited Pb-induced apoptosis of neurons in hippocampus tissue, as indicated by the decreased levels of pro-apoptotic proteins Bax and cleaved caspase-3. Furthermore, the neuroprotective effects of GAS were associated with inhibiting oxidative stress by modulating nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated antioxidant signaling. GAS supplement activated the Wnt/ß-catenin signaling pathway and reduced the expression of Wnt inhibitor Dickkopf-1 (Dkk-1). Collectively, this study clarified that GAS exhibited neuroprotective property by anti-oxidant, anti-inflammatory and anti-apoptosis effects and its ability to regulate the Wnt/Nrf2 pathway.

Effects of gastrodin against carbon tetrachloride induced kidney inflammation and fibrosis in mice associated with the AMPK/Nrf2/HMGB1 pathway.

Gastrodin (GAS), the main phenolic glycoside extracted from Gastrodia elata Blume, exhibits potential renoprotective properties. Here, we examined the protective effects of GAS on carbon tetrachloride (CCl4)-induced kidney inflammation and fibrosis in mice, and explored its underlying mechanisms. Our research findings revealed that GAS improved CCl4-induced renal damage in mice. GAS inhibited kidney fibrosis and the deposition of collagen and α-smooth muscle actin (α-SMA). GAS suppressed CCl4-induced inflammation in kidney tissue, as indicated by the decreased levels of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The renoprotective effects of GAS were associated with inhibiting oxidative stress by regulating nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated antioxidant signaling and increasing adenosine 5'-monophosphate activated protein kinase (AMPK) activation. Furthermore, GAS supplementation inactivated the receptor for advanced glycation end products (RAGE) and the high-mobility group box-1 (HMGB1) pathway. GAS inhibited the activation of Toll-like receptors (TLRs), nuclear factor-kappa B (NF-κB) and transforming growth factor (TGF)-ß. Collectively, this study clarified that GAS attenuates CCl4-induced kidney inflammation and fibrosis via the AMPK/Nrf2/HMGB1 pathway.

Ampelopsin attenuates carbon tetrachloride-induced mouse liver fibrosis and hepatic stellate cell activation associated with the SIRT1/TGF-ß1/Smad3 and autophagy pathway.

Ampelopsin (Amp), a natural flavonoid found in the vine tea of Ampelopsis grossedentata, exhibited anti-cancer, anti-oxidant, anti-inflammatory, anti-apoptosis and hepatoprotective properties. The current study instigates the protective effect of Amp on carbon tetrachloride (CCl4)-induced hepatic fibrosis and explores its underlying mechanisms. The results indicated Amp decreased the levels of liver injury markers. Amp inhibited liver fibrosis, as indicated by decreases in hepatic collagen deposition, extracellular matrix (ECM) deposition and α-smooth muscle actin (α-SMA). Amp blocked the activation of hepaticstellate cells (HSCs) by decreasing the expression of collage I, α-SMA, tissue inhibitor of matrix metalloproteinases (TIMPs) 1, transforming growth factor (TGF)-ß1, phosphorylated Smad3 (p-Smad3) and increasing the expression of matrix metalloproteinases (MMPs) 9 and SIRT1 in the model of liver fibrosis and cultured HSCs. The sirtuin 1 (SIRT1) specific inhibitor Sirtinol activated the TGF-ß1/Smad3 pathway and enhanced ECM accumulation. Attractively, Amp up-regulates the expression of autophagy-related proteins microtubule-associated protein light chain three II (LC3-II) and Beclin-1 in vivo and in vitro. However, depletion of autophagy by specific inhibitor 3-MA obviously abolished the inhibiting effect of Amp on HSC activation and hepatic fibrosis. Conclusively, these results suggest that Amp could decrease CCl4-induced hepatic fibrosis through regulating the SIRT1/TGF-ß1/Smad3 and autophagy pathway.

Role of AMPK pathway in lead-induced endoplasmic reticulum stress in kidney and in paeonol-induced protection in mice.

Paeonol is a natural flavonoid isolated from Moutan Cortex, which has been found to exhibit antioxidant, anti-apoptotic, anti-aging and anti-inflammatory bioactivities. Herein, we investigated the nephroprotective efficacy of paeonol against Pb-induced toxicity and elucidated the potential mechanisms. The results revealed that paeonol significantly ameliorated renal dysfunction and histology changes of Pb-treated mice. Paeonol inhibited oxidative stress and increased activities of antioxidant enzyme in the kidneys of Pb-treated mice. Paeonol decreased the nuclear factor-κB activation and over-production of inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Paeonol suppressed endoplasmic reticulum (ER) stress in kidneys of in the Pb treatment group and primary kidney mesangial cells. Moreover, paeonol increased the denosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation and decreased the activations of glycogen synthase kinase-3 (GSK-3), protein kinase RNA-like ER kinase (PERK), inositol-requiring protein-1 (IRE1), c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). These results were further confirmed in primary kidney mesangial cells. Taken together, these findings indicate that paeonol could protect kidney form Pb-induced injury by inhibiting oxidative stress, ER stress and inflammation via the AMPK and GSK-3 pathway. Paeonol might be a potential therapeutic agent to inhibit ER stress-associated inflammation in lead-stimulated kidneys.

Dihydromyricetin Inhibits Lead-Induced Cognitive Impairments and Inflammation by the Adenosine 5'-Monophosphate-Activated Protein Kinase Pathway in Mice.

Dihydromyricetin (DHM), a natural flavonoid derived from the medicinal and edible plant Ampelopsis grossedentata, exhibits antioxidant, antiapoptosis, antitumor, and anti-inflammatory bioactivities. This study evaluated the effects of DHM on Pb-induced neurotoxicity and explored the underlying mechanisms. DHM significantly ameliorated behavioral impairments of Pb-induced mice. It decreased the levels of lipid peroxidation and protein carbonyl and increased the activities of superoxide dismutase and catalase in the brains. DHM suppressed Pb-induced apoptosis, as indicated by the decreased levels of Bax and cleaved caspase-3. DHM also decreased inflammatory cytokines in the brains of Pb-treated mice. DHM decreased amyloid-beta (Aß) level and nuclear factor-κB nuclear translocation. Moreover, DHM induced the adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation and inhibited the activation of p38, Toll-like receptor 4, myeloid differentiation factor 88, and glycogen synthase kinase-3. Collectively, this is the first report indicating that DHM could improve Pb-induced cognitive functional impairment by preventing oxidative stress, apoptosis, and inflammation and that the protective effect was mediated partly through the AMPK pathway.

Protective effect of rutin against carbon tetrachloride-induced oxidative stress, inflammation and apoptosis in mouse kidney associated with the ceramide, MAPKs, p53 and calpain activities.

Rutin, a natural flavonoid, possess beneficial health effects. However, its renoprotective effect against carbon tetrachloride (CCl4) induced injury and the underlying mechanism is not clarified. The current study aims is to identify the therapeutic effects of rutin on oxidative stress, inflammation and apoptosis in mouse kidney exposed to CCl4. ICR mice received CCl4 with or without rutin co-administration for one week. Compared with the control group, mice receiving CCl4 alone showed kidney injury as evidenced by elevation in serum biochemical markers, inflammation, caspase-3 activity and apoptosis in kidney, while rutin administration significantly attenuated these pathophysiological changes. Exploration of the underlying mechanisms of its action demonstrated that rutin reduced the ROS, calpain and ceramide levels in mouse kidneys. Rutin significantly decreased the p53, TNF-α, IL-1ß activities and mitogen-activated protein kinase (MAPK) phosphorylation in the kidneys. In addition, rutin increased the levels of Bcl-2 protein and reduced levels protein of Bax. Rutin also inhibited the release of cytochrome C from mitochondria in kidneys of the CCl4-treated mice. Taken together, rutin ameliorates CCl4-induced oxidative stress, inflammation and apoptosis through regulating the ceramide, MAPK, p53 and calpain activities and thereby suppressing apoptosis by the mitochondrial pathway.

Association of changes in ER stress-mediated signaling pathway with lead-induced insulin resistance and apoptosis in rats and their prevention by A-type dimeric epigallocatechin-3-gallate.

A-type dimeric epigallocatechin-3-gallate (A-type-EGCG-dimer, AEd), a new proanthocyanidins dimer from persimmon fruits, has been shown to have health benefit effects. However, A-type-EGCG-dimer affects gluose metabolism in the liver and the underlying mechanism is not clarified. The present study aims to examine the protective effects of A-type-EGCG-dimer on Pb-induced hepatic insulin resistance, endoplasmic reticulum (ER) stress and apoptosis in rats. Male wistar rats exposed to 0.05% w/v Pb acetate in the drinking water with or without A-type-EGCG-dimer coadministration (200 mg/kg body weight/day, intragastrically) for three months. We found that A-type-EGCG-dimer and pioglitazone supplementation significantly deceased glucose and insulin levels in plasma as compared with the Pb group. A-type-EGCG-dimer markedly prevents Pb-induced oxidative stress, ER stress and apoptosis in livers. A-type-EGCG-dimer and pioglitazone reduced the expression levels of the GRP78, PEPCK, G6Pase, p-PERK, p-IRE1, p-JNK, ATF4, CHOP and increased p-AKT in livers of the Pb group. Moreover, A-type-EGCG-dimer reduced ROS production and restored the activities of SOD and GPx in livers. A-type-EGCG-dimer decreased Bax, cytosolic cytochrome c and cleaved caspase-3 and increased Bcl-2 in livers of Pb-exposed rats. Our results suggest that A-type-EGCG-dimer might be a potential natural candidate for the prevention of hepatic insulin resistance and apoptosis induced by Pb.

Quercitrin offers protection against brain injury in mice by inhibiting oxidative stress and inflammation.

Quercitrin is one of the primary flavonoid compounds present in vegetables and fruits. The aim of the present study was to evaluate the effects of quercitrin against carbon tetrachloride (CCl4) induced brain injury and further to elucidate its probable mechanisms. ICR mice received CCl4 intraperitoneally with or without quercitrin co-administration for 4 weeks. Our data showed that quercitrin significantly suppressed the elevation of reactive oxygen species (ROS) production and malondialdehyde (MDA) content, reduced tissue plasminogen activator (t-PA) activity, enhanced the antioxidant enzyme activities and abrogated cytochrome P450 2E1 (CYP2E1) induction in mouse brains. Quercitrin also prevented CCl4 induced cerebral function disorders associated with its ability to inhibit the activities of monoamine oxidase (MAO), acetylcholine esterase (AChE) and the N-methyl-d-aspartate receptor 2B subunit (NR2B). In addition, western blot analysis showed that quercitrin suppressed the release of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). Taken together, our findings suggested that quercitrin may be a potential candidate to be developed as a neuroprotective agent.

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

Nickel (Ni), one of hazardous environmental chemicals, is known to cause liver injury. Accumulating evidence showed that puerarin (PU) possessed comprehensive biological effects. The purpose of the current study was to test the hypothesis that the puerarin protects against enhanced liver injury caused by Ni in mice. ICR mice received intraperitoneally nickel sulfate (20 mg/kg/body weight, daily) for 20 days, and puerarin (200 and 400 mg/kg/body weight) was applied before Ni exposure. The results indicated that puerarin markedly inhibited Ni-induced liver injury, which was characterized by decreased aminotransferase activities and inflammation. Puerarin also inhibited the oxidative stress and decreased the metallothionein (MT) levels. Puerarin decreased the level of pro-inflammatory cytokines TNF-α and IL-6 in livers. Puerarin significantly inhibited the TLR4 activation and p38 MAPK phosphorylation, which in turn inhibited NF-κB activity. Likewise, Ni-induced inflammatory responses were diminished by puerarin as observed by a remarkable reduction in the levels of phosphorylated CREB. Furthermore, puerarin also reduced inflammatory mediators such as cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) levels in livers. Data from this study suggested that the inhibition of Ni-induced oxidative stress and inflammatory responses by puerarin is due to its ability to modulate the TLR4/p38/CREB signaling pathway.

Quercetin protects mouse liver against CCl4-induced inflammation by the TLR2/4 and MAPK/NF-κB pathway.

Quercetin (QE), a natural flavonoid, has many medical beneficial effects. However, its protective effects against carbon tetrachloride (CCl4) induced injury in liver have not been clarified. The aim of the present study is to illustrate the effects of QE on hepatic oxidative injury and inflammation in mice exposed to CCl4. ICR (Institute of Cancer Research) mice were exposed to CCl4 with or without QE co-administration for one week. Our results showed that QE administration significantly inhibited CCl4-induced liver injury. One of the potential mechanisms of QE action was decreasing the oxidative stress, which is consistent with decreasing of lipid peroxidation level and increasing the antioxidant enzyme activities in livers of mice. Furthermore, QE significantly decreased cytochrome P450 2E1 (CYP2E1) expression and production of pro-inflammatory markers such as inducible nitric oxide synthase (iNOS), interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2) and nitric oxide (NO) in livers of CCl4-treated mouse. In the process of exploring the underlying mechanisms of QE action, we found that QE significantly inhibited the Toll-like receptor 2 (TLR2) and the Toll-like receptor 4 (TLR4) activation and mitogen-activated protein kinase (MAPK) phosphorylation, which in turn inactivated NF-κB and the inflammatory cytokines in livers of the CCl4-treated mice. In conclusion, these results suggested that the inhibition of CCl4-induced inflammation by QE is due to its anti-oxidant activity and its ability to modulate the TLR2/TLR4 and MAPK/NF-κB signaling pathway.

Quercetin protects mouse liver against nickel-induced DNA methylation and inflammation associated with the Nrf2/HO-1 and p38/STAT1/NF-κB pathway.

Quercetin (QE), a natural flavonoid, has been reported to have many benefits and medicinal properties. However, its protective effects against nickel (Ni) induced injury in liver have not been clarified. The aim of the present study was to investigate the effects of quercetin on hepatic DNA methylation and inflammation in mice exposed to nickel. ICR mice were exposed to nickel sulfate with or without quercetin co-administration for 20 days. Our results showed that quercetin administration significantly inhibited nickel-induced liver injury, which was indicated by diagnostic indicators. In exploring the underlying mechanisms of quercetin action, we found that quercetin decreased total DNA methyltransferases (DNMTs) activity and DNA methylation level of the NF-E2 related factor 2 (Nrf2) DNA in livers of nickel-treated mice. Quercetin also induced Nrf2 nuclear translocation and heme oxygenase-1 (HO-1) activity. Moreover, quercetin decreased production of pro-inflammatory markers including TNF-α, IL-1ß and iNOS. Quercetin significantly inhibited the p38 and signal transducer and activator of transcription 1 (STAT1) activation, which in turn inactivated NF-κB and the inflammatory cytokines in livers of the nickel-treated mice. In conclusion, these results suggested that the inhibition of nickel-induced inflammation by quercetin is associated with its ability to modulate Nrf2/HO-1 and p38/STAT1/NF-κB signaling pathway.

Protective effects of ursolic acid in an experimental model of liver fibrosis through Nrf2/ARE pathway.

AIM: Liver fibrosis is a reversible wound-healing response that occurs following liver injury. In this study, we aimed to investigate the possible protective effects of ursolic acid in liver fibrosis induced by carbon tetrachloride (CCl4). METHODS: ICR mice were randomly divided into six groups (Group 1: normal; Group 2: CCl4-treated group; Group 3: CCl4 plus ursolic acid 25mg/kg group; Group 4: CCl4 plus ursolic acid 50mg/kg group; Group 5: CCl4 plus colchicine 1mg/kg group; Group 6: ursolic acid 50mg/kg group). Mice were administered with CCl4 (2 mL of CCl4 in olive oil (1:1, v/v) per kg body weight twice weekly) by intraperitoneal injection and oral injection of colchicine (1mg/kg) or ursolic acid (25, 50mg/kg) daily. After six weeks, serum aminotransferase activity, hepatic reactive oxygen species (ROS) production, thiobarbituric acid reactive substances (TBARS), antioxidase (SOD, CAT, GPx) activity and histopathological analysis were performed. The levels of nuclear factor E2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase-1 (NQO1), glutathione S-transferase (GST) and heme oxygenase-1 (HO-1), tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2) and inducible nitric oxide synthase (iNOS), Bcl-2 and caspase-3 were measured. RESULTS: Ursolic acid significantly prevented CCl4-induced hepatotoxicity and fibrosis, indicated by both diagnostic indicators and histopathological analysis. CCl4-induced profound elevations of oxidative stress, inflammation and apoptosis in liver were suppressed by ursolic acid. CONCLUSIONS: These results suggest that ursolic acid has the hepatoprotective actions. The inhibition of CCl4-induced liver fibrosis, inflammation and apoptosis by ursolic acid is due at least in part to its ability to modulate the Nrf2/ARE signalling pathway.

Proanthocyanidins improves lead-induced cognitive impairments by blocking endoplasmic reticulum stress and nuclear factor-κB-mediated inflammatory pathways in rats.

Proanthocyanidins (PCs), a class of naturally occurring flavonoids, had been reported to possess a variety of biological activities, including anti-oxidant, anti-tumor and anti-inflammatory. In this study, we examined the protective effect of PCs against lead-induced inflammatory response in the rat brain and explored the potential mechanism of its action. The results showed that PCs administration significantly improved behavioral performance of lead-exposed rats. One of the potential mechanisms was that PCs decreased reactive oxygen species production and increased the total antioxidant capacity in the brains of lead-exposed rats. Furthermore, the results also showed that PCs significantly decreased the levels of tumor necrosis factor-α, interleukin 1ß and cyclooxygenase-2 in the brains of lead-exposed rats. Moreover, PCs significantly decreased the levels of beta amyloid and phosphorylated tau in the brains of lead-treated rats, which in turn inhibited endoplasmic reticulum (ER) stress. PCs also decreased the phosphorylation of protein kinase RNA-like ER kinase, eukaryotic translation initiation factor-2, inositol-requiring protein-1, c-Jun N-terminal kinase, p38 and inhibited nuclear factor-κB nuclear translocation in the brains of lead-exposed rats. In conclusion, these results suggested that PCs could improve cognitive impairments by inhibiting brain oxidative stress and inflammatory response.