Paeoniflorin Administration Research Articles

Paeoniflorin inhibited GSDMD to alleviate ANIT-induced cholestasis via pyroptosis signaling pathway

BackgroundCholestasis (CT) is a group of disorders caused by impaired production, secretion or excretion of bile. This may result in the deposition of bile components in the blood and liver, which in turn causes damage to liver cells and other tissues. If untreated, CT can progress to severe complications, including cirrhosis, liver failure, and potentially life-threatening conditions. ObjectiveThis research was intended to elucidate the function and mechanism of Paeoniflorin (PF) in ameliorating ANIT-induced pyroptosis in CT. MethodsCT models were established in SD rats and HepG2 cells through ANIT treatment. Histological examination was conducted using haematoxylin and eosin (HE) staining to assess the histopathological alterations in the liver. Network pharmacology was employed to identify potential PF targets in CT treatment. To evaluate pyroptosis levels, various methods were used, including serum biochemical analysis, Enzyme-Linked Immunosorbent Assay (ELISA), immunofluorescence (IF), immunohistochemistry (IHC), Western blotting, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The HuProt™ 20K Chip was utilized to pinpoint potential PF-binding targets. PF's direct mechanisms in CT treatment were explored using molecular docking (MD), molecular dynamics simulations (MDS), Cellular Thermal Shift Assay (CETSA), and Surface Plasmon Resonance (SPR). ResultsPF administration was found to alleviate ANIT-induced liver pathology, enhance liver function markers, and improve cell viability. Network pharmacology and pyroptosis inhibitor studies suggested that PF might mitigate CT via the NLRP3-dependent pyroptosis pathway. This hypothesis was further supported by Western blotting, IF, and IHC analyses, which indicated PF's potential to inhibit NLRP3-dependent pyroptosis in CT. GSDMD was identified as a target through HuProt™ 20K Chip screening. The binding affinity of PF to GSDMD was validated through MD, MDS, CETSA, and SPR techniques. Additionally, the regulatory impact of GSDMD on downstream inflammatory pathways was confirmed by ELISA and IHC. CONCLUSION: PF exhibited a hepatoprotective effect in ANIT-induced CT, primarily by targeting GSDMD, thereby suppressing ANIT-induced pyroptosis and the subsequent release of inflammatory mediators.

Paeoniflorin Promotes Ovarian Development in Mice by Activating Mitophagy and Preventing Oxidative Stress.

During the development of animal organs, various adverse stimuli or toxic environments can induce oxidative stress and delay ovarian development. Paeoniflorin (PF), the main active ingredient of the traditional Chinese herb Paeonia lactiflora Pall., has protective effects on various diseases by preventing oxidative stress. However, the mechanism by which PF attenuates oxidative damage in mouse ovaries remains unclear. We evaluated the protective effects of PF on ovaries in an H2O2-induced mouse oxidative stress model. The H2O2-induced mouse ovarian oxidative stress model was used to explore the protective effect of PF on ovarian development. Histology and follicular development were observed. We then detected related indicators of cell apoptosis, oxidative stress, and autophagy in mouse ovaries. We found that PF inhibited H2O2-induced ovarian cell apoptosis and ferroptosis and promoted granulosa cell proliferation. PF prevented oxidative stress by increasing nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression levels. In addition, the autophagic flux of ovarian cells was activated and was accompanied by increased lysosomal biogenesis. Moreover, PF-mediated autophagy was involved in clearing mitochondria damaged by H2O2. Importantly, PF administration significantly increased the number of primordial follicles, primary follicles, secondary follicles, and antral follicles. PF administration improved ovarian sizes compared with the H2O2 group. The present study suggested that PF administration reversed H2O2-induced ovarian developmental delay and promoted follicle development. PF-activated mitophagy is crucial for preventing oxidative stress and improving mitochondrial quality.

MEDAG expression in vitro and paeoniflorin alleviates bone loss by regulating the MEDAG/AMPK/PPARγ signaling pathway in vivo

ObjectivesOsteoporosis (OP) is characterized by reduced bone mass and impaired bone microstructure. Paeoniflorin (PF) is isolated from peony root with anti-inflammatory, immunomodulatory, and bone-protective effects. Up to now, the mechanism of anti-OP in PF has not been completely clarified. MethodsThe expression of MEDAG in osteoclasts, osteoblasts and adipocytes was detected by RT-qPCR. The OVX mouse model was constructed, and oral administration of PF was performed for 15 weeks. Bone microstructure was detected by H&E staining and a micro-CT system, and expression of signaling proteins examined by Western blot and immunohistochemical staining. ELISA and biochemical kits were used to quantify serum metabolite levels. Key findingsMEDAG were upregulated in osteoclasts and adipocytes, and downregulated in osteoblasts. PF administration effectively alleviated OVX-induced bone loss, and histological changes in femur tissues. Moreover, PF significantly reduced serum TRAP, CTX-1, P1NP, BALP, and LDL-C levels and increased HDL-C. In addition, PF inhibited the expression of MEDAG, cathepsin K, NFATc1, PPARγ, and C/EBPα and increased p-AMPKα, OPG and Runx2. ConclusionsMEDAG is a potential target for bone diseases, and PF might attenuate OVX-induced osteoporosis via MEDAG/AMPK/PPARγ signaling pathway.

Paeoniflorin mitigates high glucose-induced lifespan reduction by inhibiting insulin signaling in Caenorhabditis elegans.

In organisms, high glucose can cause several aspects of toxicity, including the lifespan reduction. Paeoniflorin is the major component of Paeoniaceae plants. Nevertheless, the possible effect of paeoniflorin to suppress high glucose toxicity in reducing lifespan and underlying mechanism are largely unclear. Thus, in this study, we examined the possible effect of paeoniflorin in suppressing high glucose (50mM)-induced lifespan reduction and the underlying mechanism in Caenorhabditis elegans. Administration with 16-64mg/L paeoniflorin could prolong the lifespan in glucose treated nematodes. Accompanied with this beneficial effect, in glucose treated nematodes, expressions of daf-2 encoding insulin receptor and its downstream kinase genes (age-1, akt-1, and akt-2) were decreased and expression of daf-16 encoding FOXO transcriptional factor was increased by 16-64mg/L paeoniflorin administration. Meanwhile, the effect of paeoniflorin in extending lifespan in glucose treated nematodes was enhanced by RNAi of daf-2, age-1, akt-1, and akt-2 and inhibited by RNAi of daf-16. In glucose treated nematodes followed by paeoniflorin administration, the increased lifespan caused by daf-2 RNAi could be suppressed by RNAi of daf-16, suggesting that DAF-2 acted upstream of DAF-16 to regulate pharmacological effect of paeoniflorin. Moreover, in glucose treated nematodes followed by paeoniflorin administration, expression of sod-3 encoding mitochondrial Mn-SOD was inhibited by daf-16 RNAi, and the effect of paeoniflorin in extending lifespan in glucose treated nematodes could be suppressed by sod-3 RNAi. Molecular docking analysis indicated the binding potential of paeoniflorin with DAF-2, AGE-1, AKT-1, and AKT-2. Therefore, our results demonstrated the beneficial effect of paeoniflorin administration in inhibiting glucose-induced lifespan reduction by suppressing signaling cascade of DAF-2-AGE-1-AKT-1/2-DAF-16-SOD-3 in insulin signaling pathway.

Paeoniflorin Protects Retinal Ganglion Cells in Experimental Glaucoma

Glaucoma is a progressive neurodegenerative eye disease characterized by raised intraocular pressure and a loss of retinal ganglion cells, resulting in partial or total vision loss. We have investigated whether paeoniflorin could reduce intraocular pressure and improve retinal ganglion cell survival in glaucoma-induced rats. In rats with raised intraocular pressure induced by injecting hypertonic saline solution into the limbal veins, oral paeoniflorin markedly brought down the elevated intraocular pressure and significantly prevented retinal ganglion cell loss, as determined by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay and Fluoro-Gold labeling. The expression of the transforming growth factor β protein was effectively diminished by paeoniflorin administration. Also, the expression of extracellular matrix components matrix metalloproteinase 9 a tissue inhibitor of metalloproteinase 1—laminin, collagen I, and collagen IV in the optic nerve head and retinal ganglion cell layer were effectively diminished. Paeoniflorin substantially upregulated the activation of Janus kinase-2/signal transducer and activator of transcription proteins-3 signaling, which plays a crucial role in retinal ganglion cell survival. These results illustrate a protective effect of paeoniflorin through reduction of intraocular pressure, retinal ganglion cell loss, and changes in the extracellular matrix by regulating transforming growth factor β2 signaling and Janus kinase-2/signal transducer and activator of transcription protein-3 signaling. The present work demonstrates that paeoniflorin may be a promising therapeutic agent for glaucoma.

Circadian Pharmacological Effects of Paeoniflorin on Mice With Urticaria-like Lesions.

Paeoniflorin (PF) is a monoterpene glucoside with various biological properties, and it suppresses allergic and inflammatory responses in a rat model of urticaria-like lesions (UL). In the present study, we treated OVA-induced mice presenting UL with PF at four circadian time points (ZT22, ZT04, ZT10, and ZT16) to determine the optimal administration time of PF. The pharmacological effects of PF were assessed by analyzing the scratching behavior; histopathological features; allergic responses such as immunoglobulin E (IgE), leukotriene B4 (LTB4), and histamine (HIS) release; inflammatory cell infiltration [mast cell tryptase (MCT) and eosinophil protein X (EPX)]; and mRNA levels of inflammatory cytokines such as interleukin (IL)-12, IL-6, interferon-γ (IFN-γ), and IL-4. It was demonstrated that PF significantly alleviated scratching behavior and histopathological features, and ZT10 dosing was the most effective time point in remission of the condition among the four circadian time points. Moreover, PF decreased the serum levels of IgE, LTB4, and HIS, and PF administration at ZT10 produced relatively superior effectiveness. PF treatment, especially dosing at ZT10, significantly reduced the number of mast cells and granules and diminished the infiltration of MCT and EPX in the skin tissues of mice with UL. Furthermore, the oral administration of PF effectively decreased the inflammatory cytokine levels of IL-12 mRNA. In conclusion, different administration times of PF affected its efficacy in mice with UL. ZT10 administration demonstrated relatively superior effectiveness, and it might be the optimal administration time for the treatment of urticaria.

Paeoniflorin improves functional recovery through repressing neuroinflammation and facilitating neurogenesis in rat stroke model.

BackgroundMicroglia, neuron, and vascular cells constitute a dynamic functional neurovascular unit, which exerts the crucial role in functional recovery after ischemic stroke. Paeoniflorin, the principal active component of Paeoniae Radix, has been verified to exhibit neuroprotective roles in cerebralischemic injury. However, the mechanisms underlying the regulatory function of Paeoniflorin on neurovascular unit after cerebral ischemia are still unclear.MethodsIn this study, adult male rats were treated with Paeoniflorin following transient middle cerebral artery occlusion (tMCAO), and then the functional behavioral tests (Foot-fault test and modified improved neurological function score, mNSS), microglial activation, neurogenesis and vasculogenesis were assessed.ResultsThe current study showed that Paeoniflorin treatment exhibited a sensorimotor functional recovery as suggested via the Foot-fault test and the enhancement of spatial learning as suggested by the mNSS in rat stroke model. Paeoniflorin treatment repressed microglial cell proliferation and thus resulted in a significant decrease in proinflammatory cytokines IL-1β, IL-6 and TNF-α. Compared with control, Paeoniflorin administration facilitated von Willebrand factor (an endothelia cell marker) and doublecortin (a neuroblasts marker) expression, indicating that Paeoniflorin contributed to neurogenesis and vasculogenesis in rat stroke model. Mechanistically, we verified that Paeoniflorin repressed JNK and NF-κB signaling activation.ConclusionsThese results demonstrate that Paeoniflorin represses neuroinflammation and facilitates neurogenesis in rat stroke model and might be a potential drug for the therapy of ischemic stroke.

Paeoniflorin ameliorates ischemic injury in rat brain via inhibiting cytochrome c/caspase3/HDAC4 pathway.

Paeoniflorin (PF), a bioactive monoterpene glucoside, has shown a variety of pharmacological effects such as anti-inflammation and autophagy modulation etc. In this study, we investigated whether and how PF exerted a protective effect against ischemic brain injury in vivo and in vitro. Primary rat cortical neurons underwent oxygen/glucose deprivation/reperfusion (OGD/R) for 90 min. We showed that after OGD/R, a short fragment of histone deacetylase 4 (HDAC4) produced by caspase3-mediated degradation was markedly accumulated in the nucleus and the activity of caspase3 was increased. Treatment with PF (100 nM, 1 μM) significantly improved the viability of cortical neurons after OGD/R. Furthermore, PF treatment could maintain HDAC4 intrinsic subcellular localization and reduce the caspase3 activity without changing the HDAC4 at the transcriptional level. PF treatment significantly reduced OGD/R-caused inhibition of transcriptional factor MEF2 expression and increased the expression of downstream proteins such as GDNF, BDNF, and Bcl-xl, thus exerting a great anti-apoptosis effect as revealed by TUNEL staining. The beneficial effects of PF were almost canceled in HDAC4 (D289E)-transfected PC12 cells after OGD/R. In addition, PF treatment reduced the caspase9 activity, rescued the release of cytochrome c from mitochondria, and maintained the integrity of mitochondria membrane. We conducted in vivo experiments in 90-min-middle cerebral artery occlusion (MCAO) rat model. The rats were administered PF (20, 40 mg/kg, ip, 3 times at the reperfusion, 24 h and 48 h after the surgery). We showed that PF administration dose-dependently reduced infarction area, improved neurological symptoms, and maintained HDAC4 localization in rats after MCAO. These results demonstrate that PF is effective in protecting against ischemic brain injury and inhibit apoptosis through inhibiting the cytochrome c/caspase3/HDAC4 pathway.

Paeoniflorin suppresses allergic and inflammatory responses by promoting autophagy in rats with urticaria

Paeoniflorin (PF) has been reported to be effective against several skin disorders, such as allergic contact dermatitis and psoriasis; however, it remains unclear whether PF can protect against urticarial lesions. Herein, the effects of PF on rats with urticarial lesions and the possible underlying mechanism were investigated. The effects of PF administration on a rat model of ovalbumin-induced urticarial-like lesions were evaluated via pathological analysis using hematoxylin-eosin staining. Toluidine blue staining was performed to detect mast cells and ELISA was performed to determine serum histamine levels. PF-induced regulatory effects on autophagic activity and the potential underlying mechanism of this were also investigated using transmission electron microscopy, immunohistochemistry and reverse transcription-quantitative PCR. It was demonstrated that PF suppressed allergic and inflammatory responses to improve urticarial lesions, as evidenced by the attenuation of pathological abnormalities, mast cell infiltration and histamine secretion. Mechanistically, PF treatment was found to markedly limit the production and release of inflammatory cytokine interleukin (IL)-23, while the levels of IL-17 remained unchanged. PF intervention led to an increased number of autophagosomes, along with higher levels of light chain 3B (LC3B) and Beclin-1, and lower levels of P62, indicating that PF could augment autophagic activity in urticarial lesions. PF treatment increased the expression of liver kinase B1 (LKB1) and AMP-activated protein kinase-α (AMPK-α), contributing to the PF-enhanced autophagic activity. In conclusion, PF could effectively improve urticarial lesions by inhibiting inflammatory cytokine IL-23 and increasing the autophagic activity via the LKB1/AMPK-α pathway.

Paeoniflorin Alleviates Abnormalities in Rats with Functional Dyspepsia by Stimulating the Release of Acetylcholine

IntroductionPaeoniflorin is a main active component in traditional Chinese medicine. Paeoniae alba radix is widely used as a spasmolytic and pain-relieving agent for abdominal spasmodic pain. Functional dyspepsia (FD) is characterized by pain or burning in the epigastrium, fullness, bloating and nausea. However, limited information is available about the effect of paeoniflorin on FD.Materials and MethodsIn this study, iodoacetamide or clonidine-induced FD rat models were established to investigate the impacts of paeoniflorin on FD induced by different pathophysiologic disturbances.ResultsWe found the therapeutic effect of paeoniflorin through assessing the gastric emptying, gastric accommodation and visceral hypersensitivity. This function of paeoniflorin was related to the release of acetylcholine (ACh), which was accompanied by reduced acetylcholinesterase (AchE) activity in stomach and hypothalamus. Paeoniflorin administration inhibited the cyclo-oxygenase-2 (COX-2) expression and increased the level of ghrelin in the stomach. Besides, the levels of occludin and ZO-1 were elevated in the duodenum from paeoniflorin-treated rats, suggesting the impaired duodenal barrier was ameliorated.DiscussionThese results indicate that paeoniflorin possesses the ability to alleviate functional dyspepsia.

Paeoniflorin inhibited nod-like receptor protein-3 inflammasome and NF-κB-mediated inflammatory reactions in diabetic foot ulcer by inhibiting the chemokine receptor CXCR2.

Diabetic foot ulcer (DFU) is an invariably common complication of diabetes, characterized by delayed wound healing process and increased inflammation. Evidence has indicated that paeoniflorin exerts an anti-inflammatory effect in diabetic retinopathy. The current work was aimed to investigate the effect of paeoniflorin on inflammation and wound healing in DFU. DFU rat models by streptozotocin and skin biopsy punch, as well as high glucose-treated human immortalized keratinocytes (HaCaT) were established. Levels of blood glucose, wound contraction and proinflammatory cytokine were detected after paeoniflorin administration. Several essential targets associated with the NF-κB and Nod-like receptor protein-3 (NLRP3) signaling pathways were examined. Results showed markedly down-regulation of interleukin (IL)-1β, IL-18 and tumor necrosis factor-alpha in paeoniflorin-treated DFU rats. Paeoniflorin decreased the expression levels of chemokine receptor CXCR2, nuclear NF-κB and p-IκB (Ser36), as well as increased IκB level. Histological analysis and immunostaining showed lower inflammatory cells with decreased NLRP3 and cleaved caspase-1 levels following paeoniflorin treatment. Further in vitro evidence confirmed that paeoniflorin efficiently inhibited NLRP3 and NF-κB-mediated inflammation in DFU by inhibiting CXCR2. These findings are suggestive of greatly attenuated wound inflammation and better wound healing in paeoniflorin-treated DFU rats. Our study demonstrates that paeoniflorin is a potential therapeutic agent for DFU.

Antidepressant Effect of Paeoniflorin Is Through Inhibiting Pyroptosis CASP-11/GSDMD Pathway.

Nod-like receptor protein 3 (NLRP3)-associated neuroinflammation mediated by activated microglia is involved in the pathogenesis of depression. The role of the pore-forming protein gasdermin D (GSDMD), a newly identified pyroptosis executioner downstream of NLRP3 inflammasome mediating inflammatory programmed cell death, in depression has not been well defined. Here, we provide evidence that paeoniflorin (PF), a monoterpene glycoside compound derived from Paeonia lactiflora, ameliorated reserpine-induced mouse depression-like behaviors, characterized as increased mobility time in tail suspension test and forced swimming test, as well as the abnormal alteration of synaptic plasticity in the depressive hippocampus. The molecular docking simulation predicted that PF would interact with C-terminus of GSDMD. We further demonstrated that PF administration inhibited the enhanced expression of GSDMD which mainly distributed in microglia, along with the proteins involved in pyroptosis signaling transduction including caspase (CASP)-11, CASP-1, NLRP3, and interleukin (IL)-1β in the hippocampus of mice treated with reserpine. And also, PF prevented lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced pyroptosis in murine N9 microglia in vitro, evidenced by inhibiting the expression of CASP-11, NLRP3, CASP-1 cleavage, as well as IL-1β. Furthermore, VX-765, an effective and selective inhibitor for CASP-1 activation, reduced the expression of inflammasome and pyroptosis-associated proteins in over-activated N9 and also facilitated PF-mediated inhibition of pyroptosis synergistically. Collectively, the data indicated that PF exerted antidepressant effects, alleviating neuroinflammation through inhibiting CASP-11-dependent pyroptosis signaling transduction induced by over-activated microglia in the hippocampus of mice treated with reserpine. Thus, GSDMD-mediated pyroptosis in activated microglia is a previously unrecognized inflammatory mechanism of depression and represents a unique therapeutic opportunity for mitigating depression given PF administration.

Paeoniflorin attenuates gestational diabetes via Akt/mTOR pathway in a rat model.

BackgroundGestational diabetes mellitus (GDM) is a type of diabetes associated with pregnancy and may impose risks on both mother and fetus. Akt paeoniflorin was shown to have anti-inflammatory and anti-hyperglycemia properties and has a potential ability to suppress mammalian target of rapamycin (mTOR) signaling. The current study aimed to study the effect of paeoniflorin on GDM maternal, fetal, and placental characteristics in vivo.MethodsStreptozotocin (STZ)-induced gestational diabetes rat model was used in our study. The expression levels of phosphorylation (p-) and total protein expression levels of protein kinase B (Akt), mTOR, serum/glucocorticoid regulated kinase 1 (SGK1), and eIF4E-binding protein 1 (4E-BP1) in the placenta were determined by Western blot assay. The blood glucose, insulin, and leptin levels were assessed using enzyme-linked immunosorbent assay (ELISA).ResultsWe found that placental Akt/mTOR signaling was substantially upregulated in GDM patients compared with healthy donors. Paeoniflorin administration alleviates the dysregulation of blood glucose, leptin, and insulin levels in both maternal and fetal GDM rats. Paeoniflorin treatment suppressed the overactivation of Akt/mTOR signaling in placental tissues. More importantly, administration of paeoniflorin was beneficial for normalization of fetal size and body weight in the GDM rats.ConclusionOur study suggested that application of paeoniflorin may serve as a potential therapeutical strategy for patients with GDM.

Paeoniflorin attenuates impairment of spatial learning and hippocampal long-term potentiation in mice subjected to chronic unpredictable mild stress.

Paeoniflorin has been reported to exhibit antidepressant-like effects in several animal model depression; and it also exerts a neuroprotective effect. In the present study, we investigated the effects of paeoniflorin administration on depression-like behaviors and cognitive abilities in mice subjected to chronic unpredictable mild stress (CUMS), an animal model associated with depressive disorders and cognitive deficits. We administered paeoniflorin (20mg/kg), which is the main active constituent extracted from Paeonia lactiflora Pall. and exerts multiple pharmacological actions, to CUMS mice. Subsequently, animals were subjected to tests of depression-like behavior including the sucrose preference test, the forced swimming test and the tail suspension test. The Morris water maze (MWM) task was applied to evaluate learning and memory capacity. Hippocampal CA1 long-term potentiation (LTP) was recorded. Dendritic spine density and the expression levels of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95) in the hippocampus were also investigated. The administration of paeoniflorin protected against CUMS-induced depression-like behavior. Paeoniflorin also improved the performance of CUMS mice in the MWM. The impairment of hippocampal CA1 LTP caused by CUMS was also reversed. Furthermore, paeoniflorin administration prevented decreases in dendritic spine density and in the expression of BDNF and PSD95 in the hippocampus of CUMS mice. Our observations suggest that paeoniflorin is a potential antidepressant that protects against cognitive impairment in depression.

Histopathological and biochemical evaluation of paeoniflorin administration in an experimental periodontitis model.

The purpose of this study was to evaluate the effects of administered Paeoniflorin (Pae) on periodontal tissues within an experimental periodontitis model. Forty male Wistar rats were used in this study and experimental periodontitis was created in all rats except in the control group (n = 10, first group). In the periodontitis group, experimental periodontitis was created but no other application was performed (n = 10, second group). In the other groups created experimental periodontitis, systemic Pae (n = 10, third group) or saline (n = 10, fourth group) was applied. A biochemical analysis of the gingival vascular endothelial growth factor (VEGF) levels and a histomorphometric analysis (measurements of the area of alveolar bone, alveolar bone resorption, and attachment loss) were performed. In the Pae group, the area of the alveolar bone was increased, while alveolar bone resorption and attachment loss decreased. Gingival VEGF levels increased in all groups that created experimental periodontitis and the greatest increase seen in the Pae group. Histomorphometric and biochemical analyses in this study suggest that Pae has a curative effect on periodontal tissues. However, additional studies are needed to confirm these results.

Paeoniflorin has anti-inflammation and neurogenesis functions through nicotinic acetylcholine receptors in cerebral ischemia-reperfusion injury rats.

Objective(s): Paeoniflorin (PF) has anti-oxidation, anti-inflammation, anti-apoptosis, and neuroprotection pharmacological effects against ischemic injury. The aim of the present study was to investigate the neuroprotection mechanisms of PF in cerebral ischemia-reperfusion injury rats.Materials and Methods:We established an animal model of cerebral infarct by occlusion of the middle cerebral artery for 15 min, followed by reperfusion, and PF was administered 24 hr later (20 mg/kg, intraperitoneally for 6 days) after reperfusionResults:Treatment with PF reduced the neurological deficit score, improved motor function, decreased cell counts of nicotinic acetylcholine receptor (nAChR) α4β2 immunoreactive cells, and increased cell counts of nAChR α7. Furthermore, PF administration suppressed neuronal apoptosis and promoted neurogenesis.Conclusion:PF rescued neurological deficit and underlying mechanisms were inhibition of neurological apoptosis and inflammation by nAChRs.

Metabolic study of paeoniflorin and total paeony glucosides from Paeoniae Radix Rubra in rats by high-performance liquid chromatography coupled with sequential mass spectrometry.

A clear understanding of the metabolism of Traditional Chinese Medicines is extremely important in their rational clinical application and effective material foundation research. A novel and reliable strategy was performed to find more metabolites of paeoniflorin, determine the metabolites of total paeony glucosides (TPG) by means of determining those metabolites of paeoniflorin, and compare the metabolism differences between paeoniflorin and TPG by intragastric administration. This strategy was characterized as follows. Firstly, the rats were divided into two groups (the paeoniflorin group and the TPG group) to find differences in metabolism mechanisms between paeoniflorin and TPG. Secondly, UPLC-FT-ICR MS and UPLC-Q-TOF MS2 were applied to obtain accurate molecular weight and structural information, respectively. Thirdly, the metabolites were tentatively identified by a combination of data-processing methods including mass defect screening, characteristic neutral loss screening and product ion screening. Finally, a comparative study was employed in the metabolism of paeoniflorin and TPG. Based on the strategy, 18 metabolites of paeoniflorin (including four new compounds) and 11 metabolites of TPG (including two new compounds) were identified. In all of the identified metabolites of paeoniflorin, two metabolites in rat plasma, four metabolites in rat urine and six metabolites in rat feces were found for the first time after paeoniflorin administration. The results indicate that hydrolyzation of the ester bond and glucosidic band and conjugation with glucuronide were the major metabolic pathways of paeoniflorin. The metabolites of paeoniflorin and TPG in rat plasma, urine and feces have been detected for the first time after intragastric administration. The results may contribute to a better understanding of the metabolism mechanism and provide a scientific rationale for researching the material basis of paeoniflorin and TPG in vivo.

Mitigation of TGF-β/Smad signaling pathway-associated liver fibrosis by paeoniflorin

Purpose: To evaluate paeoniflorin (PF) as a possible protective agent against liver fibrosis and its likely mechanisms of action.Methods: A rat model of liver fibrosis was induced by carbon tetrachloride (CCl4) injection. Liver damage was determined by serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. The hydroxyproline content of proteins was measured as an indirect way of assessing collagen deposition. TGF-β1 levels and TGF-β/Smad signaling pathway-related genes and proteins were analyzed by quantitative polymerase chain reaction (qPCR) assay and Western blot assay.Results: After PF administration, serum ALT and AST levels were significantly (p < 0.01) reduced by 34.9 and 37.6 %, respectively. Collagen deposition was also significantly (p < 0.01) reduced by 31.0 %. Hepatic stellate cell activation was significantly inhibited, as evidenced by suppressed α-SMA expression. PF inhibited phospo-Smad 2/3 by elevating Smad 7 level.Conclusion: PF alleviates CCl4-induced liver fibrosis in a dose-dependent manner probably by restoring the balance between activated Smad 2/3 and Smad7. Thus, PF might be a source of a novel anti-fibrotic agent.Keywords: Paeoniflorin, Fibrosis, Liver, TGF-β, Hepatic stellate cell, Smad, Hydroxyproline

Paeoniflorin ameliorates cognitive dysfunction via regulating SOCS2/IRS-1 pathway in diabetic rats

Paeoniflorin is a natural monoterpene glycoside in Paeonia lactiflora pall with various biological properties including promising anti-inflammatory activity. Current evidences support that inflammatory reaction, oxidative stress, as well as abnormal insulin signaling in the hippocampus are potential causes of tau hyperphosphorylation and finally induce cognitive dysfunction. The present study aims to explore the effects of paeoniflorin on the cognitive deficits and investigate the underlying mechanisms in diabetic rats induced by a high-sucrose, high-fat diet and low dose of streptozotocin (STZ). Paeoniflorin treatment effectively improved the performance of diabetic rats in the Morris water maze test via decreasing escape latency and increasing the spent time in the target quadrant. Immunohistochemistry staining also had shown that tau hyperphosphorylation in the hippocampus was prevented after paeoniflorin administration. This function was correlated with its abilities of reducing the brain inflammatory cytokines (IL-1β and TNF-α), decreasing suppressor of cytokine signaling 2 (SOCS2) expressions and promoting insulin receptor substrate-1 (IRS-1) activity. Additionally, we also found paeoniflorin administration significantly promoted the phosphorylation levels of protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β). Together, these results showed that paeoniflorin had beneficial effects on relieving diabetes-associated cognitive deficits via regulating SOCS2/IRS-1 pathway and might provide a feasible method for the treatment of diabetes-associated cognitive dysfunction.

Paeoniflorin ameliorates interferon-alpha-induced neuroinflammation and depressive-like behaviors in mice.

Long-term treatment with high-dose Interferon-alpha (IFN-α) has resulted in depression in 30–50% of the patients. Paeoniflorin may ameliorate the IFN-α-induced depression; however, the underlying mechanism is less studied. Here, we investigated the prophylactic antidepressant and anti-neuroinflammatory effects of paeoniflorin on the behaviors and specific emotion-related regions of the brain in mice with IFN-α-induced depression. A series of behavior assessments were conducted to identify the depressive state after subcutaneously IFN-α injections and with or without intragastrically paeoniflorin administration in C57BL/6J mice. Levels of many inflammatory-related cytokines in serum, mPFC, vHi and amygdala were determined by cytokine array analysis. Furthermore, microglia and astrocyte activation in these three regions were evaluated by immunohistochemistry. We found that the mice which were subcutaneously injected IFN-α 15×106 IU/kg for 4 successive weeks to mimic an IFN-α-induced depression model had distinct inflammatory changes in the amygdala. Interestingly, 4-week 20 mg/kg or 40 mg/kg paeoniflorin pretreatments reversed the depressive-like behaviors and the abnormal inflammatory cytokine levels in the serum, mPFC, vHi and amygdala. These cytokines were not limited to the commonly reported IL-6, IL-1β and TNF-α, but also IL-9, IL-10, IL-12, and MCP-1. Besides, the increased density of microglia in IFN-α-treated mice was reversed by paeoniflorin in these three brain areas. Taken together, our data suggest that paeoniflorin can reverse the long-term, high-dose IFN-α-induced depressive-like behaviors that were associated with local distinct neuroinflammation in the mPFC, vHi and particularly the amygdala. Paeoniflorin might have a preventive therapeutic potential in IFN-α-induced depression.