Protective Effect Of Puerarin Research Articles

A high concentration of fatty acids induces TNF-α as well as NO release mediated by the P2X4 receptor, and the protective effects of puerarin in RAW264.7 cells.

Circulating levels of free fatty acids (FFAs) are often found to be increased in patients with type 2 diabetes mellitus (T2DM) and metabolic syndrome (MS). High plasma FFA levels may give rise to maladaptive macrophage activation and promote inflammatory responses, which has been proposed as a potential mechanism for the development of DM and MS. P2X4 receptor (P2X4R), a ligand-gated cation channel activated by extracellular adenosine triphosphate (ATP), plays a primary role in the regulation of inflammatory responses. Puerarin has been reported to possess potential anti-inflammatory activity. However, the anti-inflammatory activity of puerarin and the underlying molecular mechanisms in a setting of a high concentration of FFAs remain unknown. In this study, we found that a high concentration of FFAs increased the expression of P2X4R, cytosolic Ca2+ concentration and the phosphorylation of extracellular signal-regulated kinase (ERK) and induced the expression of tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS) mRNA and the release of TNF-α and nitric oxide (NO) in RAW264.7 macrophages. Such a high concentration FFA-induced inflammation may be reversed by the P2X4R selective antagonist 5-BDBD, which manifests the important role of P2X4R in the TNF-α and NO release caused by the high concentration of FFAs in RAW264.7 cells. Molecular docking data showed that puerarin could interfere with the activation of P2X4R by forming hydrogen bonding towards residue Arg267, an important residue essential for the canonical activation of P2X4R. Treatment with puerarin dose-dependently reduced high concentration FFA-elevated P2X4R expression and inhibited P2X4R-mediated inflammatory signalling, including high concentration FFA-evoked [Ca2+]i, ERK phosphorylation, expression of TNF-α and iNOS mRNA and release of TNF-α and NO. Our findings emphasize the critical role of P2X4R in high concentration FFA-induced TNF-α and NO release of RAW264.7 macrophages. Puerarin notably counteracts these high concentration FFA-induced adverse effects through its inhibition of P2X4R expression and P2X4R-mediated inflammatory signalling.

Protective effects of puerarin on acute lung and cerebrum injury induced by hypobaric hypoxia via the regulation of aquaporin (AQP) via NF-κB signaling pathway

ObjectiveHypobaric hypoxia, frequently encountered at high altitude, may lead to lung and cerebrum injury. Our study aimed to investigate whether puerarin could exert ameliorative effects on rats exposed to hypobaric hypoxia via regulation of aquaporin (AQP) and NF-κB signaling pathway in lung and cerebrum. Materials and methods40 Sprague Dawley rats were divided into four groups (normal control group, hypobaric hypoxia group, puerarin group and dexamethasone group). Wet/dry ratio, blood gas, pathological changes of lung and cerebrum and spatial memory were observed in each group. Inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were determined with ELISA and expression of AQP1, AQP4, NF-κB signaling pathway in lung and cerebrum with western blot ResultsPuerarin showed significant preventative effects on tissue injury and behavioral changes, as evidenced by histopathological findings and Morris water maze. In addition, levels of inflammatory cytokines in BALF decreased in the two preventative groups compared with those of hypobaric hypoxia group. AQP in lung and cerebrum increased under the condition of hypobaric hypoxia while was down regulated in both two preventative groups. NF-κB and IκB was also inhibited by puerarin. ConclusionOur study suggested that lung and cerebrum injury, increased inflammatory cytokines in BALF and increased AQP1, AQP4 and NF-κB signaling pathway occurred under the condition of hypobaric hypoxia. Moreover, puerarin could prevent lung and cerebrum injury of rats exposed to hypobaric hypoxia via down-regulation of inflammatory cytokines, AQP1 and AQP4 expression and NF-κB signaling pathway.

Protective Effects of Puerarin against Aβ 1-42-Induced Learning and Memory Impairments in Mice.

Puerarin is a major isoflavone glycoside from the root of Pueraria lobata. It has been reported that puerarin can protect neurons from oxidative stress-induced apoptosis. Emerging evidence suggests that oxidative damage is associated with Aβ-induced neuronal death. In the current study, we evaluated the effect of puerarin on Alzheimer's disease induced by Aβ and explored the potential mechanisms underlying this effect. We found that the escape latency of the Morris water maze was decreased in groups treated with puerarin compared to the model group (p < 0.01). In addition, there were significant differences between treated groups and the model group mice in a Y-maze test (p < 0.01). Furthermore, puerarin recovered the levels of brain-derived neurotrophic factor, phosphorylated tau, malondialdehyde, acetylcholine esterase, glycogen synthase kinase-3beta, and the activity of superoxide dismutase to some extent in the hippocampus and cerebral cortex. Shrinkage of nuclei and swollen and eccentrically dispersed neuronal bodies were observed in the hippocampus of Aβ-treated mice. These data demonstrate that puerarin might protect against cognitive deficits, oxidative stress, and neurodegeneration induced by Aβ1-42.

Protective Effect of Puerarin Against Oxidative Stress Injury of Neural Cells and Related Mechanisms.

BackgroundParkinson’s disease (PD) is manifested as degeneration of dopaminergic neurons in substantia nigra compacta. The mitochondrial dysfunction induced by oxidative stress is believed to a major cause of PD. Puerarin has been widely applied due to its estrogen nature and anti-oxidative function. This study thus investigated the protective role of puerarin against oxidative stress injury on PC12 neural cells, in addition to related mechanisms.Material/MethodsPC12 cells were pre-treated with gradient concentrations of puerarin, followed by the induction of 0.5 mM H2O2. MTT assay was used to detect cell viability. Enzyme-linked immunosorbent assay (ELISA) was employed to detect intracellular level of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH). Cell apoptosis was determined by Annexin-V/7-AAD double labelling. Reactive oxidative species (ROS) and lactate dehydrogenase (LDH) activities were then measured. Cellular levels of caspase-3 and caspase-9 were also determined.ResultsThe pre-treatment using puerarin significantly reversed H2O2-induced oxidative stress injury, as it can increase proliferation, SOD and GSH activities, decrease MDA activity, suppress apoptosis of PC12 cells, and decrease ROS and LDH production (p<0.05 in all cases). Further assays showed depressed up-regulation of caspase-3 and caspase-9 after puerarin pretreatment.ConclusionsPuerarin pretreatment can decrease activity of caspase-3 and caspase-9 activity in PC12 cells, thus protecting cells from oxidative injury.

Puerarin Protects Pancreatic β-Cells in Obese Diabetic Mice via Activation of GLP-1R Signaling.

Diabetes is characterized by a loss and dysfunction of the β-cell. Glucagon-like peptide 1 receptor (GLP-1R) signaling plays an important role in β-cell survival and function. It is meaningful to identify promising agents from natural products which might activate GLP-1R signaling. In this study, puerarin, a diet isoflavone, was evaluated its beneficial effects on β-cell survival and GLP-1R pathway. We showed that puerarin reduced the body weight gain, normalized blood glucose, and improved glucose tolerance in high-fat diet-induced and db/db diabetic mice. Most importantly, increased β-cell mass and β-cell proliferation but decreased β-cell apoptosis were observed in puerarin-treated diabetic mice as examined by immunostaining of mice pancreatic sections. The protective effect of puerarin on β-cell survival was confirmed in isolated mouse islets treated with high glucose. Further mechanism studies showed that the circulating level of GLP-1 in mice was unaffected by puerarin. However, puerarin enhanced GLP-1R signaling by up-regulating expressions of GLP-1R and pancreatic and duodenal homeobox 1, which subsequently led to protein kinase B (Akt) activation but forkhead box O1 inactivation, and promoted β-cell survival. The protective effect of puerarin was remarkably suppressed by Exendin(9-39), an antagonist of GLP-1R. Our study demonstrated puerarin improved glucose homeostasis in obese diabetic mice and identified a novel role of puerarin in protecting β-cell survival by mechanisms involving activation of GLP-1R signaling and downstream targets.

Puerarin prevents cardiac hypertrophy induced by pressure overload through activation of autophagy

This study aimed to explore the effects of puerarin on autophagy in cardiac hypertrophy. Decreased 5′-adenosine monophosphate kinase (AMPK) activity alone with inhibited autophagy could be detected in rats within 3 weeks after aortic banding (AB). Puerarin treatment for 3 weeks in AB rats significantly restored autophagy. Administration of puerarin for 6 weeks effectively restricted cardiomyocyte hypertrophy and apoptosis. In an in vitro study, similar anti-hypertrophy and anti-apoptosis effects of puerarin on isoprenaline-induced H9c2 cells were also observed. After inhibition of autophagy by pretreatment with 3-methyladenine, the protective effects of puerarin were blocked. Further in vivo study demonstrated that puerarin significantly enabled phosphorylation of 5′-AMPK to be activated, subsequently inhibiting expression of the mammalian target of rapamycin (mTOR) target proteins S6 ribosomal protein and 4E-binding protein 1. All these data indicate that puerarin exerts protective effects against cardiomyocyte hypertrophy and apoptosis, partly by restoration of autophagy through AMPK/mTOR-mediated signaling.

Protective effects of puerarin against Aß40-induced vascular dysfunction in zebrafish and human endothelial cells

Aß40-induced vascular dysfunction has been implicated in the pathogenesis of Alzheimer׳s disease (AD). In the present study, we investigated the possible protective effects of puerarin against Aß40-induced vascular damage and impairment to angiogenesis in transgenic TG (fli1:EGFP) zebrafish and human endothelial cells. Aß40 peptides at 5μM caused an obvious reduction of vessel branches in the subintestinal vein basket, induced NADPH oxidase-derived reactive oxygen species and impaired vascular endothelial growth factor (VEGF)-dependent angiogenesis. Pretreatment with puerarin attenuated Aβ40-induced vessel reduction and impairment to angiogenesis in a dose-dependent manner. In addition, Aß40 decreased VEGF-dependent phosphorylation of Akt and eNOS, whereas puerarin treatment attenuated these detrimental effects. Furthermore, the restoration of Aß40-induced-angiogenesis impairment by puerarin was abolished by either the PI3 kinase inhibitor LY294002 (10μM) or eNOS inhibitor L-NAME. The present study suggests that puerarin exerts its protective action probably through reduction of NADPH oxidase-derived reactive oxygen species overproduction and activation of the PI3K/Akt/eNOS pathways.

The protective effects of puerarin in cardiomyocytes from anoxia/reoxygenation injury are mediated by PKCε

Puerarin is an isoflavone isolated from traditional Chinese medicine Ge-gen (Radix Puerariae). Clinical studies have confirmed the cardioprotective effects of puerarin; however, the mechanisms underlying these effects are still unclear. On the basis of previous findings, we hypothesized that puerarin protects cardiomyocytes from ischemia-reperfusion injury via the protein kinase C epsilon (PKCε) (a critical cardioprotective protein) signalling pathway. Neonatal rat primary cardiomyocytes were preconditioned with puerarin or puerarin plus εV1-2, a selective PKCε inhibitor, prior to anoxia/reoxygenation (A/R) treatment. Western blot analysis showed that expression and activity of PKCε protein in puerarin preconditioned group were both increased compared with the control or A/R group. Subsequent assays showed that preconditioning with puerarin could increase the viability of neonatal rat primary cardiomyocytes treated with A/R, decreased the generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential, cell necrosis and apoptosis induced by A/R injury. However, the protective effects of puerarin completely disappeared in the group pretreated with puerarin plus εV1-2. Thus, for the first time, we revealed the protective effects of puerarin in cardiomocytes from anoxia/reoxygenation injury are mediated by PKCε.

Puerarin protected the brain from cerebral ischemia injury via astrocyte apoptosis inhibition

Puerarin is extensively attractive because of its superior neuroprotective effects in stroke prevention. This paper focused on the protective effect of puerarin both in vivo and in vitro. Middle cerebral artery occlusion (MCAO) was operated on male Sprague-Dawley rat for 2 h, different doses of puerarin (2.62, 7.86 and 23.59 mg/kg) or vehicle were gavaged 1 h after reperfusion. Rats were sacrificed after 24 h or 7 days treatment of puerarin/vehicle. In 7.86 and 23.59 mg/kg groups, infarct volume was reduced (P < 0.05) when puerarin was given once; 7 days puerarin intervention further reduced the infarct volume (P < 0.05) compared with vehicle-treated animal. The modified neurological severity score (mNSS) was also raised in day 4 in 7.86 and 23.59 mg/kg groups and in all groups in day 7 compared with vehicle (P < 0.05). The number of Nissl body, cleaved caspase-3 and GFAP positive cells increased observably after stroke in dose-dependence in rats. In our in vitro study, we have found that puerarin inhibited the pro-apoptosis factor and upregulated the BDNF secret of astrocytes after OGD-R. This indicated that the repairing effect of puerarin was associated with the astrocyte protection.

Hepatoprotective activity of puerarin against carbon tetrachloride-induced injuries in rats: A randomized controlled trial

The protective effects of puerarin on liver damage were evaluated by carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats. Male rats were orally treated with puerarin daily, and received CCl₄ intraperitoneally twice a week for 4 weeks. Our results showed that puerarin at doses of 50, 100, and 200 mg/kg b. w. significantly reduced the elevated activities of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase at least 15%, 17%, 14% and 18%, respectively. In addition, puerarin at different doses significantly decreased (p<0.05) the level of hepatic thiobarbituric acid reactive substances compared to the CCl₄-treated group. Furthermore, the treatment of puerarin was also found to significantly increase the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and glutathione content at least 40%, 12%, 25%, 52%, 17% and 44% in the liver of CCl₄-treated rats, respectively. Liver histopathology also showed that puerarin reduced the incidence of liver lesions induced by CCl₄. The results suggest that puerarin exhibits potent hepatoprotective effects on CCl₄-induced liver damages in rats, and that the hepatoprotective effects of puerarin may be due to both the inhibition of lipid peroxidation and to increase of antioxidant enzymes activity.

Protective effects of puerarin on experimental chronic lead nephrotoxicity in immature female rats

Puerarin (PU), a natural flavonoid, has been reported to possess anti-oxidative and anti-inflammatory activities. In the present study, female Sprague-Dawley rats received lead (Pb) nitrate (300mg/L, via drinking water) and/or PU (400mg/kg/day, orally) to investigate the protective effects of PU on Pb-induced renal damage. Renal toxicity was evaluated by detecting urinary proteins excretion as well as levels of serum urea nitrogen and serum creatinine. Ultrastructural observations and real-time quantitative polymerase chain reaction analyses were performed on kidney cortex tissues to identify the mitochondrial damage and quantify gene expression levels of cytochrome oxidase submits (COX-I/II/III), respectively. Renal cell damage was assessed by light microscopic examination. Lipid peroxidation (LPO) levels and antioxidant status in kidney were also evaluated. Animals that received both Pb and PU showed a better renal function than those that received Pb alone, with minor pathological damage. Moreover, PU significantly reduced LPO and markedly restored the enzymatic and non-enzymatic antioxidants levels in kidney of Pb-treated rats, which may be related to its restoring mitochondrial function. Furthermore, PU administration significantly increased urinary Pb excretion and decreased its level in the serum and kidney. In conclusion, these results suggested that PU reduces renal damage induced by chronic Pb administration through its antioxidant properties and chelating ability.

Protective effect of puerarin against beta-amyloid-induced oxidative stress in neuronal cultures from rat hippocampus: involvement of the GSK-3β/Nrf2 signaling pathway

Current evidence suggests that amyloid beta (Aβ) peptides may play a major role in the pathogenesis of Alzheimer's disease in part by eliciting oxidative stress. Puerarin, a major isoflavone glycoside from Kudzu root (Pueraria lobata), has been reported to exert estrogen-like and antioxidant activities. The central hypothesis guiding this study is that puerarin will prevent or at least markedly attenuate Aβ25–35-induced excess production of reactive oxygen species (ROS) by interrupting glycogen synthase kinase-3β (GSK-3β) signaling. In this study, we demonstrate that pretreatment of primary hippocampal neurons with puerarin significantly reduced Aβ25–35-induced oxidative stress characterized by scavenging of ROS and inhibiting lipid peroxidation. Puerarin induced expression of nuclear Nrf2 protein, but not in the Nrf2 mRNA level, and increased heme oxygenase-1 (HO-1) levels at levels of transcription and translation. Puerarin-induced Serine 9 phosphorylation of GSK-3β was blocked by lithium chloride treatment in primary hippocampal neurons, indicating the participation of the GSK-3β inactivation. This protective effect was partially reversed when GSK-3β were blocked by the chemical inhibitors such as lithium chloride. These results suggest puerarin as a phytoestrogen with potential of a possible therapeutic agent in neurodegenerative diseases involving oxidative stress.

Protective Effect of Puerarin on β-Amyloid-Induced Neurotoxicity in Rat Hippocampal Neurons

Puerarin (CAS Number 3681-99-0), a major isoflavone glycoside purified from Pueraria lobata, was reported to possess antioxidative and estrogen-like biological activities. Recent studies showed that puerarin protects different cell types from damage caused by a variety of toxic stimuli. In the present study, we investigated the neuroprotective effect of puerarin against Aβ25-35-induced neurotoxicity in cultured hippocampal neurons, as well as the underlying mechanism(s). Following exposure of cells to Aβ25-35, cell survival and glutathione peroxidase (GSH-Px) and catalase (CAT) activities were reduced while production of reactive oxygen species (ROS) was increased. Preincubation of the cells with puerarin prior to Aβ25-35 exposure increased cell survival and GSH-Px and CAT activities and decreased ROS production. It was previously shown that overactivation of glycogen synthase kinase-3β (GSK-3β) is implicated in Aβ-induced cell death. In this study, Aβ25-35 treatment is found to increase GSK-3β activity and pretreatment with puerarin preventesAβ-induced activation of GSK-3β based on Western blot analysis. In addition, puerarin is shown to activate protein kinase B (PKB)/Akt, an important upstream kinase of GSK-3β, possibly promoting subsequent GSK-3β inhibition. Our data suggest that puerarin attenuates cell death induced by Aβ25-35 via various mechanisms, which might be beneficial for the treatment of Alzheimer's disease.

Involvement of activation of PI3K/Akt pathway in the protective effects of puerarin against MPP+-induced human neuroblastoma SH-SY5Y cell death

In an attempt to clarify the protective effect of puerarin on toxin-insulted dopaminergic neuronal death, this present study was carried out by using a typical Parkinson’s disease (PD) model – 1-methyl-4-phenylpyridinium iodide (MPP+)-induced dopaminergic SH-SY5Y cellular model. Data are presented, which showed that puerarin up-regulated Akt phosphorylation in both of MPP+-treated and non-MPP+-treated cells. The presence of PI3K inhibitor LY294002 completely blocked puerarin-induced activation of Akt phosphorylation. Moreover, puerarin decreased MPP+-induced cell death, which was blocked by phosphoinositide 3-kinase (PI3K) inhibitor LY294002. We further demonstrated that puerarin protected against MPP+-induced p53 nuclear accumulation, Puma (p53-upregulated mediator of apoptosis) and Bax expression and caspase-3-dependent programmed cell death (PCD). This protection was blocked by applying a PI3K/Akt inhibitor. Additionally, it was Pifithrin-α, but not Pifithrin-μ, which blocked MPP+-induced Puma and Bax expression, caspase-3 activation and cell death. Collectively, these data suggest that the activation of PI3K/Akt pathway is involved in the protective effect of puerarin against MPP+-induced neuroblastoma SH-SY5Y cell death through inhibiting nuclear p53 accumulation and subsequently caspase-3-dependent PCD. Puerarin might be a potential therapeutic agent for PD.

Protective effects of puerarin against 1-methyl-4-phenylpyridinium-induced mitochondrial apoptotic death in differentiated SH-SY5Y cells

It is well known that puerarin possesses protective activity on neurodegenerative diseases. However, the exact path way involved in the protective effect of puerarin on MPP+ -induced cell death is unclear. In this study, we focused on mitochondria im pairment in the apoptotic process of MPP+ -elicited SH-SY5Y cells and detected the protection of puerarin. As evidenced by Trypan blue assay, the cell viability was significantly decreased by 1 mmol x L(-1) MPP+, but reversed by different concentrations puerarin pre treatment. Flow cytometer analysis revealed that MPP+ -induced SH-SY5Y cells apoptosis and arrested the cells in G2/M phase, where as puerarin pretreatment concentration dependently reversed the apoptosis ratio. In addition to the apoptosis ratio, 50.0 micromol x L(-1) puerarin pretreatment even altered the MPP+ -induced G2/M phase arrest. JC-1 assay suggested that MPP+ significantly opened MMP of the SH-SYSY cells; pretreatment with puerarin attenuated the deterioration of the MMP. Both ELISA and Western blotting showed that puerarin prevented the release of cytochrome c from the mitochondrial interior to the cystol elicited by MPP+. DNA ladder showed that typical DNA ladder was present in the MPP+ -induced SH-SY5Y cells. Additionally, MPP+ enhanced caspase-9 and caspase-3 ac tivity, respectively, while not caspase-8. However,the enhancement was concentration dependently blocked by puerarin pretreatment. Taken together, puerarin can modulate mitochondrial membrane potential and inhibit the cytochrome c releasing-caspase cascade to pre vent MPP+ -induced cell injury.

Protective effects of puerarin on lens epithelial cells in rat diabetic cataract

The therapeutic effects of general and local applications of puerarin in the treatment of streptozotocin (STZ)-induced rat diabetic model were compared. Experimental research. We equally divided normal Sprague-Dawley (SD) rats into a STZ group, a peritoneal injection group, a peribulbar injection group and a control group. STZ, peritoneal injection and peribulbar injection groups were first treated with STZ. Subsequently, the STZ group was injected with normal saline intraperitoneally, while in the later two groups puerarin was injected through peritoneal and peribular routes, respectively. Control group only received peritoneal injection of saline. The morphology of lens epithelial cells (LEC) and their subcellular structure were examined by bright-field microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) 20, 40 and 60 days after the injection. Nitrogen oxide (NO) and nitric oxide synthase (NOS) were measured by biochemistry methods. Finally, inducible nitric oxide synthase (iNOS) protein and mRNA levels were monitored by Western blot and RT-PCR, respectively. Data was processed with two factorial experiment analysis of variance. Twenty to sixty days after the injection, marked or complete lens opacities appeared in the STZ group, whereas only slight opacities appeared in the lens in peritoneal and peribulbar puerarin groups and the lens in the control group remained clear. At the 20th, 40th and 60th day after the injection, optical microscope detected pathological changes of LEC in the STZ group. The cell volume was decreased with a dense nucleus and many bubbles appeared around the equator area. Under TEM, enlargement of cell gap, vacuoles in the cytoplasm, swelling of mitochondria and unclear structure of rough endoplasmic reticulum appeared in the LEC of the STZ group. Part of the nucleus was in karyopyknosis and peripheral nucleus gap was enlargement. Under SEM, normal fiber conjunction structure of the lens disappeared, fibers were swelling, part of fiber membranes were discontinuous, detached, and accumulated in certain areas. Mild lens opacities detected by bright-field microscope were developed in peritoneal and peribulbar puerarin injection groups. Nucleus and fibers in the lens cells of both groups appeared to be normal, with minor swelling of mitochondria, minor enlargement of endoplasmic reticulum and slight increase of intracellular space. NO, NOS and iNOS protein and mRNA of the lens were increased and up-regulated in STZ group. In the other two groups only minor changes were present and the changes were significantly less than that of the STZ group but greater than that in the control group. Peritoneal and peribulbar injection of puerarin have similar therapeutic effects in the treatment of rat diabetic cataract.

Protective effects of puerarin on liver injury induced by D‐galactosamine in rats

Puerarin is an isoflavone C‐glycoside isolated from Pueraria lobata. It has been suggested that puerarin possesses various beneficial effects including antioxidation, hypocholesterolemic action and neuroprotection, but the mechanism of its action is still unclear. In this study, we examined the protective effects of puerarin against D‐galactosamine (GalN)‐induced liver injury. Adult male rats were treated with puerarin 3 hr prior to GalN challenge. Pretreatment of rats with puerarin inhibited the increase in serum alanine aminotransferase, aspartate aminotransferase and sorbitol dehydrogenase activities and TNF‐α level significantly. Histopathological examination showed that hepatocyte swelling, inflammation, degeneration and necrosis were all inhibited by puerarin. Also puerarin elevated the oxyradical scavenging capacity of liver toward peroxynitrite, peroxyl and hydroxyl radials. Western blot analysis showed that puerarin treatment reduced the hepatic expression of iNOS, NF‐κB and cleavaged caspase 3 stimulated by GalN. Superoxide dismutase activity, glutathione, NO levels and expression of catalase and glutathione peroxidase in liver were unaffected. The present results suggest that the protective effects of puerarin against GalN‐induced hepatotoxicity may be associated with its ability to inhibit the TNF‐α‐related inflammatory response.

Protective Effect of Puerarin on Acute Alcoholic Liver Injury

To provide experimental and theoretical basis for the clinical application of Puerarin in acute alcohol poisoning, 30 Wistar rats were randomized into 3 groups as follows: (1) Group A (control) underwent normal sodium (N.S.) peritoneal injection (i.p.) and intragastric administration (i.g.); (2) Group B (alcohol) underwent an equivalent dosage of N.S. i.p. and 40% ethanol (8000 mg/kg. d).ig for 5 days; (3) Group C (Puerarin) underwent Puerarin 200 mg/kg. d. ip, and an equivalent dosage of ethanol for 5 days. The left lobes of livers were sampled, and the levels of MDA, SOD and GPX in plasma and liver homogenate were detected. The level of MDA in plasma and liver homogenate in the alcohol group was obviously higher than that in the control group (p < 0.05, respectively), while that in the Puerarin group was significantly lower than in the alcohol group (p < 0.05, respectively). The levels of SOD and GPX were opposite to that of MDA. Under a light microscope, the livers of the rats in the alcohol group showed unclear structure of hepatic lobules, stiffness of hepatic sinusoids, diffused lipid degeneration of hepatic cells, cellular swelling, and focal necrosis, while the structure remained clear in the Puerarin group. Under the electron microscope, lipid degeneration, cell organ decrease, enlargement of endoplasmic reticulum, reduced quantity of hepatins and swelling of mitochondria were observed in cells of the model group. However, the pathologistic changes were slight in the Puerarin group. In conclusion, Puerarin may have the function of inhibiting the oxidative stress induced by acute alcoholism.

Protective effect of puerarin on rats with alcoholic hepatitis

Protective effect of puerarin on rats with alcoholic hepatitis

Involvement of ubiquitin proteasome system in protective mechanisms of Puerarin to MPP +-elicited apoptosis

It has been well documented that dysfunction of ubiquitin proteasome system (UPS) in the neuron exacerbated the Parkinson's disease (PD). However, whether or not UPS is involved in the protective effect of Puerarin on 1-Methyl-4-Phenyl-1, 2, 3, 6-Tetrahydropyridine (MPP +)-elicited cell death is yet to be elucidated. In this study, treatment of SH-SY5Y cells with 1 mM MPP +-elicited a characteristic apoptotic cell death and pretreatment with Puerarin protected cells against MPP +-induced apoptosis as evidenced by promoting cell viability, improving morphological changes and reducing apoptotic rate. To further explore the potential protective mechanism of Puerarin in MPP +-induced SH-SY5Y cell death, UPS activity, mitochondria-dependent apoptosis and caspase-3 activity were measured. Puerarin pretreatment attenuated MPP +-induced dysfunction of protease activity, thereby reducing accumulation of ubiquitin-conjugated proteins. Meanwhile, caspase-3 activity was remarkably attenuated by Puerarin. In addition, the ratio of bcl-2/bax was increased by Puerarin in comparison with MPP +-treated group. Taken together, these results suggest that Puerarin could protect MPP +-induced SH-SY5Y cells from apoptosis by regulating the function of UPS.