Isochlorogenic acid A ameliorated lead-induced anxiety-like behaviors in mice by inhibiting ferroptosis-mediated neuroinflammation via the BDNF/Nrf2/GPX4 pathways.

Lead (Pb) is a common environmental neurotoxicant that causes behavioral impairments in both rodents and humans. Isochlorogenic acid A (ICAA), a phenolic acid found in a variety of natural sources such as tea, fruits, vegetables, coffee, plant-based food products, and various medicinal plants, exerts multiple effects, including protective effects on the lungs, livers, and intestines. The objective of this study was to investigate the potential neuroprotective effects of ICAA against Pb-induced neurotoxicity in ICR mice. The results indicate that ICAA attenuates Pb-induced anxiety-like behaviors. ICAA reduced neuroinflammation, ferroptosis, and oxidative stress caused by Pb. ICAA successfully mitigated the Pb-induced deficits in the cholinergic system in the brain through the reduction of ACH levels and the enhancement of AChE and BChE activities. ICAA significantly reduced the levels of ferrous iron and MDA in the brain and prevented decreases in GSH, SOD, and GPx activity. Immunofluorescence analysis demonstrated that ICAA attenuated ferroptosis and upregulated GPx4 expression in the context of Pb-induced nerve damage. Additionally, ICAA downregulated TNF-α and IL-6 expression while concurrently enhancing the activations of Nrf2, HO-1, NQO1, BDNF, and CREB in the brains of mice. The inhibition of BDNF, Nrf2 and GPx4 reversed the protective effects of ICAA on Pb-induced ferroptosis in nerve cells. In general, ICAA ameliorates Pb-induced neuroinflammation, ferroptosis, oxidative stress, and anxiety-like behaviors through the activation of the BDNF/Nrf2/GPx4 pathways.

Lead-induced liver fibrosis and inflammation in mice by the AMPK/MAPKs/NF-κB and STAT3/TGF-ß1/Smad2/3 pathways: the role of Isochlorogenic acid a.

Lead (Pb) is a nonessential heavy metal, which can cause many health problems. Isochlorogenic acid A (ICAA), a phenolic acid present in tea, fruits, vegetables, coffee, plant-based food products, and various medicinal plants, exerts multiple effects, including anti-oxidant, antiviral, anti-inflammatory and antifibrotic functions. Thus, the purpose of our study was to determine if ICAA could prevent Pb-induced hepatotoxicity in ICR mice. An evaluation was performed on oxidative stress, inflammation and fibrosis, and related signaling. The results indicate that ICAA attenuates Pb-induced abnormal liver function. ICAA reduced liver fibrosis, inflammation and oxidative stress caused by Pb. ICAA abated Pb-induced fibrosis and decreased inflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-alpha (TNF-α). ICAA abrogated reductions in activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Masson staining revealed that ICAA reduced collagen fiber deposition in Pb-induced fibrotic livers. Western blot and immunohistochemistry analyses showed ICAA increased phosphorylated AMP-activated protein kinase (p-AMPK) expression. ICAA also reduced the expression of collagen I, α-smooth muscle actin (α-SMA), phosphorylated extracellular signal-regulated kinase (p-ERK), phosphorylated c-jun N-terminal kinase (p-JNK), p-p38, phosphorylated signal transducer and phosphorylated activator of transcription 3 (p-STAT3), transforming growth factor ß1 (TGF-ß1), and p-Smad2/3 in livers of mice. Overall, ICAA ameliorates Pb-induced hepatitis and fibrosis by inhibiting the AMPK/MAPKs/NF-κB and STAT3/TGF-ß1/Smad2/3 pathways.

Hepatoprotective effect of avicularin on lead-induced steatosis, oxidative stress, and inflammation in mice associated with the MAPK/HSP60/NLRP3 and SREBP1c pathway.

Lead (Pb), an environmental hazard, causes severe diseases in the liver, kidney, cardiovascular system, hematopoietic system, reproductive system, and nervous system. Avicularin (AVI), the main dietary flavonoid found in many citrus fruits, exhibited potential protective properties on organs. However, the molecular mechanisms of these protective actions are currently not clear. In our study, the effects of AVI on Pb-induced hepatotoxicity were evaluated using ICR mice. Changes in oxidative stress, inflammation, lipid metabolism, and related signaling were evaluated. We found for the first time that treatment with AVI significantly reduced hepatic steatosis, inflammation, and oxidative stress induced by Pb. AVI attenuated Pb-induced liver dysfunction and lipid metabolism disorder in mice. AVI decreased the serum biochemical indicators of lipid metabolism. AVI decreased the expression levels of lipid metabolism-related protein SREBP-1c, acetyl-CoA carboxylase (ACC), and FAS. AVI suppressed Pb-induced inflammation in livers, as indicated by decreasing the TNF-α and IL-1ß levels. AVI suppressed oxidative stress by increasing the activation of SOD, CAT, and GPx. Furthermore, AVI inhibited the activities of JNK, ERK, p38, and NF-κB. AVI further decreased the levels of HSP60, NLRP3, p-IκBα, and p-p65 in the livers of mice. Collectively, this study indicated that AVI mitigated Pb-induced hepatic steatosis, oxidative stress, and inflammation by regulating the SREBP-1c and MAPK/HSP60/NLRP3 signaling pathways.

Isochlorogenic acid B alleviates lead-induced anxiety, depression and neuroinflammation in mice by the BDNF pathway.

Lead (Pb) can cause neurobehavioral abnormalities. Isochlorogenic acid B (ICAB), a dietary flavonoid found in tea, sweet potato, artichoke, propolis and several plants, exhibited potential neuroprotective properties. In this study, we aimed to investigate the mechanisms of Pb-induced anxiety, depression and neuroinflammation, and the neuroprotective effect of ICAB in mouse brains. We found that ICAB supplementation significantly improved behavioral abnormalities, neuroinflammation and oxidative stress induced by Pb. ICAB attenuated Pb-induced anxiety and depression behavior in mice, as indicated by decreasing the duration of immobility in tail suspension test and increasing the crossing number, rearing number and time in center in open field test. Accordingly, ICAB inhibited oxidative stress by decreasing malondialdehyde (MDA) level and increasing the antioxidant enzyme activity. ICAB also inhibited Pb-induced inflammation in brain, as indicated by decreasing the tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels. ICAB increased the expression levels of brain derived neurotrophic factor (BDNF) and the phosphorylation of cAMP-responsive element binding protein (CREB), phosphoinositide 3-kinases-protein kinase B (PI3K/AKT). Furthermore, ICAB decreased the levels of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), glycogen synthase kinase-3 beta (GSK-3ß) and p38. Collectively, this study demonstrated that ICAB improved Pb-induced anxiety, depression, neuroinflammation and oxidative stress by regulating the BDNF signaling pathway.

Avicularin Attenuates Lead-Induced Impairment of Hepatic Glucose Metabolism by Inhibiting the ER Stress-Mediated Inflammatory Pathway.

Lead (Pb), an environmental hazard, causes several human diseases. Avicularin (Avi), a main dietary flavonoid found in several plants and fruits, exhibits potential protective properties on organs. However, the molecular mechanisms of Avi's protective effects against Pb-induced damage are not clear. In our study, the effects of Avi on Pb-induced hepatotoxicity were evaluated using ICR mice. We have revealed for the first time that treatment with Avi significantly reduced hepatic inflammation, endoplasmic reticulum stress (ERS) and glucose metabolism disorder induced by Pb. Avi decreased the serum biochemical indicators of glucose metabolism. Avi increased the activities of glycogenolysis rate-limiting enzyme hexokinase (HK), pyruvate kinase (PK), glucokinase (GK) and glycogen phosphorylase (PYG) and inhibited the activities of gluconeogenesis rate-limiting enzyme phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphate dehydrogenase (G6PD). Avi decreased the protein expression levels of glucose-regulated protein 78 (GRP78), phosphorylated inositol requiring enzyme 1 (p-IRE1), phosphorylated RNA-dependent protein kinase-like ER kinase (p-PERK) and phosphorylated eukaryotic initiation factor 2α (p-eIF2α). The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were decreased in the liver as a result of Avi suppression Pb-induced inflammation. These results indicated that Avi attenuated Pb-induced impairment of hepatic glucose metabolism by the ERS and inflammation pathway.

Nephroprotective effect of gastrodin against lead-induced oxidative stress and inflammation in mice by the GSH, Trx, Nrf2 antioxidant system, and the HMGB1 pathway.

Gastrodin (GAS), the main phenolic glycoside derivative from Gastrodiaelata Blume, has several bio-activities. However, the molecular mechanisms of these protective actions currently remain unclear. This study aimed to investigate the mechanisms of GAS on lead (Pb)-induced oxidative stress and inflammation in the kidneys and primary kidney mesangial cells. Results indicated that GAS improved Pb-induced renal dysfunction and morphological changes in mice. GAS ameliorated Pb-induced inflammation in kidneys by reducing the TNF-α and IL-6 levels. GAS inhibited Pb-induced oxidative stress by regulating the glutathione, thioredoxin (Trx), and Nrf2 antioxidant systems. Furthermore, GAS supplementation increased the activation of SOD, GPx, HO-1, and NQO1 in the kidneys. GAS decreased the expression levels of HMGB1, TLR4, RAGE, MyD88, and NF-κB. These results were further confirmed in primary kidney mesangial cells. Collectively, this study demonstrated that GAS alleviated Pb-induced kidney oxidative stress and inflammation by regulating the antioxidant systems and the Nrf2 signaling pathway. Highlights Gastrodin ameliorated Pb-induced kidney injury in mice.Gastrodin inhibited oxidative stress and inflammation in kidneys.Gastrodin activated the GSH, Trx and Nrf2 antioxidant system in kidneys.Gastrodin inhibited the activities of HMGB1. RAGE, TLR4, and MyD88.

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.

Fisetin improves lead-induced neuroinflammation, apoptosis and synaptic dysfunction in mice associated with the AMPK/SIRT1 and autophagy pathway.

Fisetin, a natural flavonoid found in plants, fruits and vegetables, exerts anti-cancer, anti-oxidant, anti-inflammatory and anti-mitotic effects. The current study instigates the protective effect of fisetin against lead-induced synaptic dysfunction, neuroinflammation and neurodegeneration in mice, and explores its underlying mechanisms. The results indicated fisetin can significantly ameliorated behavioral impairments in Pb-treated mice. Fisetin inhibited Pb-induced the apoptotic neurodegeneration, as indicated by the decreased levels of Bax and cleaved caspase-3. Fisetin suppressed activations of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), NF-κB and subsequently inactivate pro-inflammatory factor including interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). It can also decrease the accumulation of p-tau and amyloid-beta (Aß) and increased the expression of the Aß remover neprilysin (NEP) in brains of mice. Fisetin also reversed Pb-induced synaptic dysfunction by increasing the levels of synaptosomal associated protein-25 (SNAP-25), postsynaptic density-95 (PSD-95), cyclic-AMP-response element-binding protein (CREB) phosphorylation and calcium/calmodulin kinase II (CaMKII) phosphorylation. Fisetin promoted Pb-induced autophagy in the brains of mice. Moreover, fisetin can increase levels of the denosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation and SIRT1. Fisetin may be developed as a potential nutritional target for the prevention of Pb-induced neurotoxicity.

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.

Wolbachia Infection Dynamics in Tribolium confusum (Coleoptera: Tenebrionidae) and Their Effects on Host Mating Behavior and Reproduction.

Wolbachia interact with their hosts in a broad variety of relationships that range from parasitism to mutualism. To improve the understanding of complex relationships between Wolbachia and host, we performed not only mating and crossing experiments to investigate effects of Wolbachia on mate choice, mating performance, and reproduction in the confused flour beetles Tribolium confusum (Jacquelin du Val), but also quantitative PCR to determine Wolbachia spatiotemporal infection density dynamics within beetles. Wolbachia induced strong cytoplasmic incompatibility, but had no effects on male mate choice and mating performance. Compared with Wolbachia-uninfected females, infected females had very high fecundity irrespective of male's infection status. Wolbachia infection densities in beetles were higher in eggs and adults and in the reproductive tissues and abdomens, whereas Wolbachia density in adults did not differ between sexes and among different ages. These results suggest that Wolbachia have evolved mutualistic interactions with T. confusum, which provides the first evidence of Wolbachia mutualisms in this beetle species. We discussed these findings and their evolutionary implications in light of Wolbachia-host interactions.

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.