Anti-oxidative and TNF-α suppressive activities of puerarin derivative (4AC) in RAW264.7 cells and collagen-induced arthritic rats

Pharmacological mechanisms of puerarin in the treatment of Parkinson's disease: An overview

Puerarin, a monomer of traditional Chinese medicine, is a key component of Pueraria radix. Both clinical and experimental researches demonstrated that puerarin has therapeutic effects on Parkinson's disease (PD). Puerarin's pharmacological mechanisms include: 1) Anti-apoptosis. Puerarin inhibits cell apoptosis through the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (Akt) and c-Jun N-terminal kinase (JNK) signaling pathways. Puerarin also exerts a hormone-like effect against cell apoptosis; 2) Anti-oxidative stress injury. Puerarin inhibits the Nrf2 nuclear exclusion through the GSK-3β/Fyn pathway to promote the Nrf2 accumulation in the nucleus, and then promotes the antioxidant synthesis through the Nrf2/ARE signaling pathway to protect against oxidative stress; 3) Neuroprotective effects by intervening in the ubiquitin-proteasome system (UPS) and autophagy-lysosomal pathway (ALP). Puerarin significantly enhances the activity of chaperone-mediated autophagy (CMA), which downregulates the expression of α-synuclein, reduces its accumulation, and thus improves the function of damaged neurons. Additionally, puerarin increases proteasome activity and decreases ubiquitin-binding proteins, thereby preventing toxic accumulation of intracellular proteins; 4) Alleviating inflammatory response. Puerarin inhibits the conversion of microglia to the M1 phenotype while inducing the transition of microglia to the M2 phenotype. Furthermore, puerarin promotes the secretion of anti-inflammatory factor and inhibits the expression of pro-inflammatory factors; 5) Increasing the levels of dopamine and its metabolites. Puerarin could increase the levels of dopamine, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatum; 6) Promoting neurotrophic factor expression and neuronal repair. Puerarin increases the expression of glial cell-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), thereby exerting a neuroprotective effect. Moreover, the regulation of the gut microbiota by puerarin may be a potential mechanism for the treatment of PD. The current review discusses the molecular mechanisms of puerarin, which may provide insight into the active components of traditional Chinese medicine in the treatment of PD.

Puerarin Alleviates H2O2-Induced Oxidative Stress and Blood-Milk Barrier Impairment in Dairy Cows

During the perinatal period, the bovine mammary epithelial cells of dairy cows exhibit vigorous metabolism and produce large amounts of reactive oxygen species (ROS). The resulting redox balance disruption leads to oxidative stress, one of the main causes of mastitis. Puerarin (PUE) is a natural flavonoid in the root of PUE that has attracted extensive attention as a potential antioxidant. This study first investigated whether PUE could reduce oxidative damage and mastitis induced by hydrogen peroxide (H₂O₂) in bovine mammary epithelial cells in vitro and elucidated the molecular mechanism. In vitro, BMECs (Bovine mammary epithelial cells) were divided into four treatment groups: Control group (no treatment), H₂O₂ group (H₂O₂ stimulation), PUE + H₂O₂ group (H₂O₂ stimulation before PUE rescue) and PUE group (positive control). The growth of BMECs in each group was observed, and oxidative stress-related indices were detected. Fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of tightly linked genes, antioxidant genes, and inflammatory factors. The expression of p65 protein was detected by Western blot. In vivo, twenty cows with an average age of 5 years having given birth three times were divided into the normal dairy cow group, normal dairy cow group fed PUE, mastitis dairy cow group fed PUE, and mastitis dairy cow group fed PUE (n = 5). The contents of TNF-α, IL-6, and IL-1β in milk and serum were detected. In BMECs, the results showed that the PUE treatment increased the activities of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC); ROS and malondialdehyde (MDA) levels were reduced. Thus, PUE alleviated H₂O₂-induced oxidative stress in vitro. In addition, the PUE treatment eliminated the inhibition of H₂O₂ on the expression of oxidation genes and tight junction genes, and the enrichment degree of NRF-2, HO-1, xCT, and tight junctions (claudin4, occludin, ZO-1 and symplekin) increased. The PUE treatment also inhibited the expression of NF-κB-associated inflammatory factors (IL-6 and IL-8) and the chemokine CCL5 in H₂O₂-induced BMECs. In vivo experiments also confirmed that feeding PUE can reduce the expression of inflammatory factors in the milk and serum of lactating dairy cows. In conclusion, PUE can effectively reduce the oxidative stress of bovine mammary epithelial cells, enhance the tight junctions between cells, and play an anti-inflammatory role. This study provides a theoretical basis for PUE prevention and treatment of mastitis and oxidative stress. The use of PUE should be considered as a feed additive in future dairy farming.

Efficacy and safety of dietary polyphenols in rheumatoid arthritis: A systematic review and meta-analysis of 47 randomized controlled trials

Objective

To evaluate safety and efficacy of dietary polyphenols in the treatment of rheumatoid arthritis (RA).

Methods

CNKI, Pubmed, Cochrane library, Embase were searched to collect randomized controlled trials (RCTs) of dietary polyphenols in the treatment of RA. The databases were searched from the time of their establishment to November 8nd, 2022. After 2 reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies, Meta-analysis was performed using RevMan5.4 software.

Results

A total of 49 records (47 RCTs) were finally included, involving 3852 participants and 15 types of dietary polyphenols (Cinnamon extract, Cranberry extract, Crocus sativus L. extract, Curcumin, Garlic extract, Ginger extract, Hesperidin, Olive oil, Pomegranate extract, Puerarin, Quercetin, Resveratrol, Sesamin, Tea polyphenols, Total glucosides of paeony). Pomegranate extract, Resveratrol, Garlic extract, Puerarin, Hesperidin, Ginger extract, Cinnamon extract, Sesamin only involve in 1 RCT. Cranberry extract, Crocus sativus L. extract, Olive oil, Quercetin, Tea polyphenols involve in 2 RCTs. Total glucosides of paeony and Curcumin involve in more than 3 RCTs. These RCTs showed that these dietary polyphenols could improve disease activity score for 28 joints (DAS28), inflammation levels or oxidative stress levels in RA. The addition of dietary polyphenols did not increase adverse events.

Conclusion

Dietary polyphenols may improve DAS28, reduce C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and improve oxidative stress, etc. However, more RCTs are needed to verify or modify the efficacy and safety of dietary polyphenols.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022315645.

Puerarin@Chitosan composite for infected bone repair through mimicking the bio-functions of antimicrobial peptides

It is important to eliminate lipopolysaccharide (LPS) along with killing bacteria in periprosthetic joint infection (PJI) therapy for promoting bone repair due to its effect to regulate macrophages response. Although natural antimicrobial peptides (AMPs) offer a good solution, the unknown toxicity, high cost and exogenetic immune response hamper their applications in clinic. In this work, we fabricated a nanowire-like composite material, named P@C, by combining chitosan and puerarin via solid-phase reaction, which can finely mimic the bio-functions of AMPs. Chitosan, serving as the bacteria membrane puncture agent, and puerarin, serving as the LPS target agent, synergistically destroy the bacterial membrane structure and inhibit its recovery, thus endowing P@C with good antibacterial property. In addition, P@C possesses good osteoimmunomodulation due to its ability of LPS elimination and macrophage differentiation modulation. The in vivo results show that P@C can inhibit the LPS induced bone destruction in the Escherichia coli infected rat. P@C exhibits superior bone regeneration in Escherichia coli infected rat due to the comprehensive functions of its superior antibacterial property, and its ability of LPS elimination and immunomodulation. P@C can well mimic the functions of AMPs, which provides a novel and effective method for treating the PJI in clinic.

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P@C was fabricated through solid reaction with chitosan and puerarin.

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P@C punctures bacteria membrane and eliminates LPS, thus sterilizes bacteria.

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P@C improves bone formation of PEEK under infection via polarizing macrophage to M2.

A mechanistic review of chinese medicine polyphenols on bone formation and resorption

Bone reconstruction includes a steady state system of bone formation and bone absorption. This tight coupling requires subtle coordination between osteoblasts and osteoclasts. If this balance is broken, it will lead to bone mass loss, bone density reduction, and bone metabolic diseases, such as osteoporosis. Polyphenols in Chinese herbal medicines are active ingredients in plant extracts with high safety and few side effects, and they can play a role in affecting bone formation and bone resorption. Some of these have estrogen-like effects and can better target bone health in postmenopausal women. The purpose of this review is to provide comprehensive information on the mechanisms underlying the relationship between traditional Chinese medicine polyphenols and bone formation or bone resorption.

Transcriptomic profiling revealed the role of apigenin-4'-O-α-L-rhamnoside in inhibiting the activation of rheumatoid arthritis fibroblast-like synoviocytes via MAPK signaling pathway

BACKGROUND

Activated fibroblast-like synoviocyte (FLS) played a significant role in the pathogenesis and progression of rheumatoid arthritis (RA). Apigenin-4'-O-α-L-rhamnoside showed remarkable effects against RA, however, no relevant studies on pharmacology of apigenin-4'-O-α-L-rhamnoside yet, the effects and underlying molecular mechanism of apigenin-4'-O-α-L-rhamnoside on RA are still unclear.

PURPOSE

This study aimed to investigate the therapeutic effects and mechanisms of apigenin-4'-O-α-L-rhamnoside on RA-FLS cells by transcriptomic analysis.

METHODS

In vitro, RA-FLS cell viability and migration were measured by CCK-8 and scratch assays, respectively. The effects of apigenin-4'-O-α-L-rhamnoside on inflammatory levels of MMP-1, MMP-3, RANKL and TNF-α in RA-FLS cells were detected using ELISA kits. High-throughput transcriptome analysis was performed to screen the key genes and related pathways of apigenin-4'-O-α-L-rhamnoside inhibit RA-FLSs, and the result of which were validated by RT-qPCR and western blot. Furthermore, in vivo, we also evaluated the effects of apigenin-4'-O-α-L-rhamnoside in rat with CIA.

RESULTS

Apigenin-4'-O-α-L-rhamnoside significantly suppressed RA-FLS migration, exerted remarkable inhibiting effects on the expression levels on MMP-1, MMP3, RANKL and TNF-α in RA-FLS cells. It seemed that MAPK signaling pathway might be closely related to the pathogenesis of RA by down-regulated relevant core targets (MAPK1, HRAS, ATF-2, p38 and JNK). Moreover, apigenin-4'-O-α-L-rhamnoside attenuated the severity of arthritis in CIA rat.

CONCLUSION

Apigenin-4'-O-α-L-rhamnoside inhibited pro-inflammatory cytokine, chemokine and MMPs factors production of RA-FLS by targeting the MAPK signaling pathway, which provided a scientific basis for potential application in the treatment of RA.

The Advances of Broad-Spectrum and Hot Anti-Coronavirus Drugs

Coronaviruses, mainly including severe acute respiratory syndrome virus, severe acute respiratory syndrome coronavirus 2, Middle East respiratory syndrome virus, human coronavirus OC43, chicken infectious bronchitis virus, porcine infectious gastroenteritis virus, porcine epidemic diarrhea virus, and murine hepatitis virus, can cause severe diseases in humans and livestock. The severe acute respiratory syndrome coronavirus 2 is infecting millions of human beings with high morbidity and mortality worldwide, and the multiplicity of swine epidemic diarrhea coronavirus in swine suggests that coronaviruses seriously jeopardize the safety of public health and that therapeutic intervention is urgently needed. Currently, the most effective methods of prevention and control for coronaviruses are vaccine immunization and pharmacotherapy. However, the emergence of mutated viruses reduces the effectiveness of vaccines. In addition, vaccine developments often lag behind, making it difficult to put them into use early in the outbreak. Therefore, it is meaningful to screen safe, cheap, and broad-spectrum antiviral agents for coronaviruses. This review systematically summarizes the mechanisms and state of anti-human and porcine coronavirus drugs, in order to provide theoretical support for the development of anti-coronavirus drugs and other antivirals.

The Role of Reactive Oxygen Species in the Rheumatoid Arthritis-Associated Synovial Microenvironment

Rheumatoid arthritis (RA) is an inflammatory disease that begins with a loss of tolerance to modified self-antigens and immune system abnormalities, eventually leading to synovitis and bone and cartilage degradation. Reactive oxygen species (ROS) are commonly used as destructive or modifying agents of cellular components or they act as signaling molecules in the immune system. During the development of RA, a hypoxic and inflammatory situation in the synovium maintains ROS generation, which can be sustained by increased DNA damage and malfunctioning mitochondria in a feedback loop. Oxidative stress caused by abundant ROS production has also been shown to be associated with synovitis in RA. The goal of this review is to examine the functions of ROS and related molecular mechanisms in diverse cells in the synovial microenvironment of RA. The strategies relying on regulating ROS to treat RA are also reviewed.

Puerarin alleviates cadmium-induced oxidative damage to bone by reducing autophagy in rats

Autophagy is a regulatory mechanism involved in cadmium (Cd)-induced bone toxicity and is suppressed by various stimuli, including oxidative stress. Puerarin is an isoflavonoid compound isolated from Pueraria, a plant used in traditional Chinese medicine. The underlying mechanisms of action of puerarin remain unclear. The objective of this study was to explore the mitigating effects of puerarin on cadmium-induced oxidative damage in the bones of rats. Cadmium exposure increased oxidative damage in rat bones; this was markedly decreased by puerarin treatment, as demonstrated by changes in the activity of antioxidative enzymes. Cadmium-induced blockage of the expression of key bone regulatory proteins, autophagy-related markers, and signaling molecules was also alleviated by puerarin treatment. Additionally, cadmium reduced expression of the autophagic protein Rab7 and of late endosomal/lysosomal adaptor and MAPK and mTOR activator 1 (LAMTOR1); the decrease in these proteins was not restored by puerarin treatment. We speculate that puerarin relieves the inhibition of fusion of autophagosomes with lysosomes that is induced by cadmium; however, this specific effect of puerarin and downstream effects on bone regulatory mechanisms require further investigation. In conclusion, puerarin alleviates cadmium-induced oxidative damage in the bones of rats by attenuating autophagy, which is likely associated with the antioxidant activity of puerarin.

Puerarin attenuates cisplatin-induced apoptosis of hair cells through the mitochondrial apoptotic pathway

Puerarin, one of the main components of Pueraria lobata, has been reported to possess a wide range of pharmacological activities, including anti-inflammatory, antioxidative and anti-apoptotic effects. However, the role of puerarin in ototoxic drug-induced hair cell injury has not been well characterized. This study explored whether puerarin protects against cisplatin-induced hair cell damage and its potential mechanisms. The viability of puerarin-treated HEI-OC1 cells was assessed by CCK8 assay. Reactive oxygen species (ROS) was estimated with flow cytometric analysis using Cellrox Green fluorescent probe. Apoptosis-related protein levels were detected by western blot analysis. Immunostaining of the organ of Corti was performed to determine mice cochlear hair cell survival. Our results showed that puerarin improved cell viability and suppressed apoptosis in the cisplatin-damaged HEI-OC1 cells and cochlear hair cells. Mechanistic studies revealed that puerarin attenuated mitochondrial apoptosis pathway by regulating apoptotic related proteins, such as Bax and cleaved caspase-3, and attenuated ROS accumulation after cisplatin damage. Moreover, puerarin was involved in regulating the Akt pathway in HEI-OC1 cells in response to cisplatin. Our results demonstrated that puerarin administration decreased the sensitivity to apoptosis dependent on the mitochondrial apoptotic pathway by reducing ROS generation, which could be used as a new protective agent against cisplatin-induced ototoxicity.

Puerarin Prevents Acute Liver Injury via Inhibiting Inflammatory Responses and ZEB2 Expression

Puerarin, an isoflavone component extracted from herb radix puerariae, is widely used in China in the treatment of immune diseases and inflammation. Previous studies have demonstrated that puerarin prevented acute lung injury by regulating inflammatory responses. However, the effect of puerarin on acute liver injury (ALI) was unclear. The purpose of this study was to explore the beneficial effects of puerarin when applied to ALI. We found that puerarin inhibited liver injury and inflammatory cell infiltration in lipopolysaccharide (LPS)/D-galactose (D-Gal)-induced acute liver failure and the liver pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) in liver tissues with ALI and LPS-induced L-02 cells but upregulated the expression level of zinc finger E-box-binding homeobox 2 (ZEB2). Significantly, the results of this study showed that the inhibition of liver pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) production in LPS-induced L-02 cells was caused by ZEB2 overexpression. However, knocking down ZEB2 promoted LPS-mediated secretion of liver pro-inflammatory cytokines in L-02 cells. Additional experiments showed that puerarin inhibited the activation of the NF-κB signaling pathway by elevating ZEB2 expression in L-02 cells. In summary, puerarin most likely prevented activation of the pro-inflammatory factors and reduced LPS/D-Gal-induced liver injury by enhancing the ZEB2 expression level and, consequently, blocking activation of the NF-κB signaling pathway in the liver.

The Therapeutic Effect of Ge-Gen Decoction on a Rat Model of Primary Dysmenorrhea: Label-Free Quantitative Proteomics and Bioinformatic Analyses

Ge-Gen decoction (GGD) is widely used for the treatment of primary dysmenorrhea (PD) in China. However, the mechanisms that underlie this effect are unclear. We investigated the protective mechanism of GGD in a rat model of PD using label-free quantitative proteomics. The model was established by the administration of estradiol benzoate and oxytocin. Thirty rats were divided into three groups (ten rats/group): a control group (normal rats), a model group (PD rats), and a treatment group (PD rats treated with GGD). The serum levels of prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) were measured by ELISA. Nanohigh-performance liquid chromatography-tandem mass spectrometry (nano-HPLC-MS/MS) was used to identify differentially expressed proteins (DEPs), and bioinformatics was used to investigate the protein function. Proteomic data were validated by western blot analysis. Oxytocin-induced writhing responses and abnormal serum levels of PGE2 and PGF2α were reversed following the administration of GGD. A total of 379 DEPs were identified; 276 were identified between the control group and the model group, 144 were identified between the model group and the treatment group, and 41 were identified as DEPs that were common to all groups. Bioinformatics revealed that the DEPs between the control group and the model group were mainly associated with cellular component biogenesis and binding processes. The DEPs between the model group and the treatment group were mainly involved in the protein binding and metabolic process. The expression levels of HSP90AB1 and the phosphorylation levels of ERK, JNK, and P-p38 in the uteri of rats in the three groups were consistent with the proteomic findings; MAP kinases (ERK, JNK, and p38) are known to be involved in the production of inflammatory cytokines and oxytocin signaling while HSP90AB1 is known to be associated with estrogen signaling. Collectively, these data indicate that GGD may exert its protective function on PD by regulating the inflammatory response and signaling pathways associated with oxytocin and estrogen.

Puerarin enhances intestinal function in piglets infected with porcine epidemic diarrhea virus

Puerarin has been reported to be an excellent antioxidant, anti-inflammatory and antimicrobial agent, but the potential effect of puerarin on porcine epidemic diarrhea virus (PEDV) is unclear. This study aimed to determine whether puerarin could alleviate intestinal injury in piglets infected with PEDV. A PEDV (Yunnan province strain) infection model was applied to 7-day-old piglets at 104.5 TCID50 (50% tissue culture infectious dose). Piglets were orally administered with puerarin at the dosage of 0.5 mg/kg body weight from day 5 to day 9. On day 9 of the trial, piglets were inoculated orally with PEDV. Three days later, jugular vein blood and intestinal samples were collected. Results showed puerarin reduced morbidity of piglets infected with PEDV. In addition, puerarin reduced the activities of aspartate aminotransferase and alkaline phosphatase, the ratio of serum aspartate aminotransferase to serum alanine aminotransferase, the number of white blood cells and neutrophils, and the plasma concentrations of interleukin-6, interleukin-8 and tumor necrosis factor-α, as well as protein abundances of heat shock protein-70 in PEDV-infected piglets. Moreover, puerarin increased D-xylose concentration but decreased intestinal fatty acid-binding protein concentration and diamine oxidase activity in the plasma of piglets infected with PEDV. Puerarin increased the activities of total superoxide dismutase, glutathione peroxidase and catalase, while decreasing the activities of myeloperoxidase and concentration of hydrogen peroxide in both the intestine and plasma of PEDV-infected piglets. Puerarin decreased mRNA levels of glutathione S-transferase omega 2 but increased the levels of nuclear factor erythroid 2-related factor 2. Furthermore, puerarin increased the abundance of total eubacteria (16S rRNA), Enterococcus genus, Lactobacillus genus and Enterobacteriaceae family in the intestine, but reduced the abundance of Clostridium coccoides in the caecum. These data indicate puerarin improved intestinal function in piglets infected by PEDV and may be a promising supplement for the prevention of PEDV infection.

Polyherbal formula SC-E3 inhibits rheumatoid arthritis activity in a mouse model of type-II collagen-induced arthritis

OBJECTIVE

SC-E3 is a polyherbal formula that contains five medicinal herbs used frequently in traditional herbal medicine. In our previous study, we demonstrated the antioxidant and anti-inflammatory effects of SC-E3. The present study examined the effects of SC-E3 in a mouse model of type-II collagen-induced arthritis (CIA).

METHODS

In vivo, male DBA/1J mice were immunized by intradermal injection of bovine type-II collagen and complete or incomplete Freund's adjuvant, to induce arthritis. SC-E3 was orally administered daily for 23 days. In vitro, bone marrow-derived macrophages (BMMs) were treated with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) in the absence or presence of SC-E3.

RESULTS

Administrations of SC-E3 were found to have anti-arthritic effects in the joints of CIA mice, as evidenced by reduced paw swelling, bone erosion and deformation, inflammatory cell infiltration, and inflammation in synovial membrane. SC-E3 also reduced serum levels of tumor necrosis factor-α, interleukin-1β, aspartate aminotransferase and alanine aminotransferase. Furthermore, tartrate-resistant acid phosphatase-positive osteoclast numbers in the joints were significantly lower in SC-E3-treated CIA mice than in CIA mice. In addition, the differentiations of BMMs to multinucleated osteoclasts induced by M-CSF and RANKL stimulation were dose-dependently reduced by SC-E3.

CONCLUSION

These results suggest that SC-E3 possesses substantial anti-arthritic activity because it inhibits pro-inflammatory cytokines and osteoclastogenesis, and that SC-E3 has potential therapeutic use for the treatment of rheumatoid arthritis.

A mechanistic insight of phytoestrogens used for Rheumatoid arthritis: An evidence-based review

Assessment of the potential therapeutic benefits offered by naturally occurring phytoestrogens necessitate inspection of their potency and sites of action in impeding the chronic, systemic, autoimmune, joint destructing disorder Rheumatoid arthritis (RA). Possessing structural and functional similarity with human estrogen, phytoestrogen promisingly replaces the use of hormone therapy in eradicating RA symptoms with their anti-inflammatory, anti-oxidative, anti-proliferative, anti-angiogenesis, immunomodulatory, joint protection properties abolishing the harmful side effects of synthetic drugs. Scientific evidences revealed that use of phytoestrogens from different chemical categories including flavonoids, alkaloids, stilbenoids derived from different plant species manifest beneficial effects on RA through various cellular mechanisms including suppression of pro-inflammatory cytokines in particular tumor necrosis factor (TNF-α), interleukin(IL-6) and nuclear factor kappa B (NF-κB) and destructive metalloproteinases, inhibition of oxidative stress, suppressing inflammatory signalling pathways, attenuating osteoclastogenesis ameliorating cartilage degradation and bone erosion. This review summarizes the evidences of different phytoestrogen treatment and their pharmacological mechanisms in both in vitro and in vivo studies along with discussing clinical evaluations in RA patients showing phytoestrogen as a promising agent for RA therapy. Further investigations and more clinical trials are mandatory to clarify the utility of these plant derived compounds in RA prevention and in managing oestrogen deficient diseases in patients.

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

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

Quantitative Proteomic Analysis Reveals Antiviral and Anti-inflammatory Effects of Puerarin in Piglets Infected With Porcine Epidemic Diarrhea Virus

Porcine epidemic diarrhea virus (PEDV) has caused enormous economic losses to the swine industry worldwide in recent years. Puerarin (PR), a major isoflavonoid isolated from the Chinese herb Gegen, possesses many pharmacological activities, including anti-inflammatory, and anti-viral activities. This study was conducted with both PEDV-infected African green monkey kidney cells (Vero) and neonatal pigs to determine the effect of PR on PEDV infection and to elucidate the underlying mechanisms by using proteomic analyses. Twenty-four piglets fed a milk replacer were randomly allocated into one of three groups (Control, PEDV, and PEDV + PR). After a 5-day period of adaption, piglets (n = 8/group) in the PEDV + PR were orally administered with PR (0.5 mg/kg body weight) between days 5 and 9, whereas piglets in the other two groups received the same volume of liquid milk replacer. On day 9, piglets were orally administered with either sterile saline or PEDV (Yunnan province strain) at 10^4.5 TCID₅₀ (50% tissue culture infectious dose) per pig. On day 12 of the trial, jugular vein blood and intestinal samples were collected. In addition, Vero cells were assigned randomly into three groups (Control, PEDV, PEDV + PR). Cells in the PEDV and PEDV + PR groups were infected with PEDV at a multiplicity of infection of 0.01, while cells in the control group were treated with the same volume of sterile saline. One hour later, cells in the Control and PEDV groups were cultured in serum-free DMEM, while cells in the PEDV + PR group were supplemented with PR. After 36 h of culture, cells were harvested. PR attenuated the reductions in cell proliferation in vitro and growth performance in PEDV-infected piglets, and inhibited PEDV replication and the expression of several cytokines (including IL-8) both in vitro and in vivo. Proteomic analyses identified that the abundances of 29 proteins in the ileum were altered by PEDV infection and restored to the control level by PR. Pathway analyses revealed that PR restored the expression of several interferon-stimulated genes and selectively upregulated the expression of guanylate-binding proteins. Western blot analyses showed that PR supplementation inhibited the PEDV-induced NF-κB activation. Collectively, these results indicate that PR could exert antiviral and anti-inflammatory effects in piglets infected with PEDV and have the potential to be an effective antiviral feed additive.

Saussureae Involucratae Herba (Snow Lotus): Review of Chemical Compositions and Pharmacological Properties

Saussureae Involucratae Herba is the dried ground part of Saussurea involucrata (Kar. et Kir.) Sch.-Bip, which is also named as “Snow lotus” and being used in traditional Uyghur and/or Chinese medicine. This rare herb can be found at 4,000 m elevation in western part of Tianshan Mountain, Xinjiang China. According to China Pharmacopoeia (2015), the major pharmaceutical values of “Snow lotus” (Xuě liánhuā in Chinese) are alleviating rheumatoid arthritis, accelerating blood circulation and mitigating other “cold” syndromes. Traditionally, the clinical application of “Snow lotus” includes the treatments in inflammation-associated disorder, blood circulation acceleration and heat and dampness elimination. Recent studies suggested that “Snow lotus” possessed therapeutic effects associating with anti-cancer, anti-oxidation, adipogenesis suppression and neuroprotection activities, which were proposed to be related with its bioactive constitutes, i.e. acacetin, hispidulin, and rutin. In the present review, we aim to summarize pharmacological effects and underlying cell signaling pathways of “Snow lotus” in treating various medical problems.

Puerarin Exerts Protective Effects on Wear Particle-Induced Inflammatory Osteolysis

Wear particle-stimulated inflammatory bone destruction and the consequent aseptic loosening remain major postoperative problems for artificial joints. Studies have indicated that puerarin promotes osteogenesis and alleviates lipopolysaccharide-induced osteoclastogenesis in vitro. However, the underlying molecular mechanism by which puerarin interacts with receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated osteoclast formation in vitro and wear particle-stimulated osteolysis in vivo has not been reported. In this work, the protective effects exerted by puerarin on titanium particle-stimulated bone destruction in vivo and on RANKL-induced osteoclast activation in osteoclastic precursor cells in vitro were investigated. As expected, puerarin significantly inhibited wear particle-mediated bone resorption and proinflammatory cytokine productions in a calvarial resorption model. Additionally, puerarin inhibited RANKL-induced osteoclast activation, bone resorption ability, and F-actin ring formation in vitro as puerarin concentration increased. Furthermore, mechanistic investigation indicated that reduced RANKL-stimulated MEK/ERK/NFATc1 signaling cascades might regulate the protective effect of puerarin. Conclusively, these results indicate that puerarin, a type of polyphenol, might serve as a protective agent to prevent osteoclast-related osteolytic diseases.

Construction of C-glycosides of heterocycles containing the pyrimidin-2-amine or the 1H-pyrazolo[3,4-b]pyridine moiety and their biological evaluation for anticancer activities

A series of novel C-glycosides of heterocyclic derivatives containing a pyrimidin-2-amine or a 1 H-pyrazolo[3,4- b]pyridine moiety were synthesized using condensation reactions of the substituted puerarin with guanidine or 3-amino-5-hydroxypyrazole in methyl alcohol. Their chemical structures were characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and high-resolution mass spectrometry. In addition, their biological activity has been demonstrated by in vitro evaluation against the human leukemia cells K562 and human prostate cancer cells PC-3 by MTT-based assays, using the commercially available standard drug of cis-platin as a positive control. The results also demonstrated that most of the compounds showed considerable cytotoxicity to these two cell lines of K562 and PC-3, and indicated that novel C-glycosides of heterocyclic derivatives may be potential leads for further biological screenings and may generate drug-like molecules.

Whole-Cell Catalytic Synthesis of Puerarin Monoesters and Analysis of Their Antioxidant Activities

Puerarin, an important isoflavonoid from the edible root of Pueraria lobata, shows multiple bioactivities but suffers from low bioavailability. In this study, a new whole-cell catalytic method for acylation modification of puerarin was developed. Among the 12 strains tested, Aspergillus oryzae showed the highest catalytic activity and selectively catalyzed acylation of puerarin at the 6″-hydroxyl group. The organic solvents used significantly influenced the catalytic efficiency of the cells. In the green solvent 2-methyltetrahydrofuran, the reaction showed high substrate conversion (92.5%) and regioselectivity (95.8%), with results similar to those with tetrahydrofuran (94.2% and 98.5%, respectively) under optimal conditions. The monoester products showed higher liposolubility in comparison to puerarin, and those with C3-C8 fatty acid chain lengths showed evidently improved antioxidant activity toward erythrocyte hemolysis. Considering the operational stability of the cells and efficiency of the scaled-up reactions, this method is efficient and cost effective, with promising applications in the health food industry.

Puerarin Mitigates Diabetic Hepatic Steatosis and Fibrosis by Inhibiting TGF-β Signaling Pathway Activation in Type 2 Diabetic Rats

Lipid metabolism disorder and inflammation are essential promoters in pathogenesis of liver injury in type 2 diabetes. Puerarin (PUR) has been reported to exert beneficial effects on many diabetic cardiovascular diseases and chemical-induced liver injuries, but its effects on diabetic liver injury and its mechanism are still unclear. The current study was designed to explore the therapeutic effect and mechanism of PUR on liver injury in a type 2 diabetic rat model induced by a high-fat diet combined with low-dose streptozotocin. The diabetic rats were treated with or without PUR (100 mg/kg/day) by gavaging for 8 weeks, and biochemical and histological changes in liver were examined. Results showed that treatment with PUR significantly attenuated hepatic steatosis by regulating blood glucose and ameliorating lipid metabolism disorder. Liver fibrosis was relieved by PUR treatment. PUR inhibited oxidative stress and inflammation which was associated with inactivation of NF-κB signaling, thereby blocking the upregulation of proinflammatory cytokines (IL-1β, TNF-α) and chemokine (MCP-1). This protection of PUR on diabetic liver injury is possibly related with inhibition on TGF-β/Smad signaling. In conclusion, the present study provides evidence that PUR attenuated type 2 diabetic liver injury by inhibiting NF-κB-driven liver inflammation and the TGF-β/Smad signaling pathway.

Puerarin prevents LPS-induced acute lung injury via inhibiting inflammatory response

Acute lung injury (ALI) is a critical illness syndrome with high morbidity and mortality in patients. Inflammation has been known to be involved in the development of ALI. The purpose of this study was to investigate the effect of puerarin on lipopolysaccharide (LPS)-induced ALI in mice. The pro-inflammatory cytokines TNF-α, IL-6 and IL-1β were determined by ELISA. Western blot analysis was used for detecting the expression of NF-κB, IκBα, and LXRα. And myeloperoxidase (MPO) activity, lung wet/dry (W/D) ratio, and histopathological examination were also detected in lung tissues. The results showed that puerarin significantly inhibited LPS-stimulated MPO activity in lung tissues. Meanwhile, puerarin attenuated lung histopathological changes and lung wet/dry (W/D) ratio. We also found that the expression of pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β were inhibited by puerarin. Puerarin also inhibited LPS-induced TNF-α in RAW264.7 cells and IL-8 in A549 cells. From the results of western blotting, puerarin significantly suppressed LPS-stimulated NF-κB activation. And the expression of LXRα was dose-dependently increased by treatment of puerarin. The inhibition of puerarin on TNF-α production in RAW264.7 cells and IL-8 production in A549 cells were blocked by LXRα inhibitor geranylgeranyl pyrophosphate (GGPP). These results suggested that puerarin attenuated ALI by activating LXRα, which subsequently inhibited LPS-induced inflammatory response.

Text Mining of Rheumatoid Arthritis and Diabetes Mellitus to Understand the Mechanisms of Chinese Medicine in Different Diseases with Same Treatment

OBJECTIVE

To identify the commonalities between rheumatoid arthritis (RA) and diabetes mellitus (DM) to understand the mechanisms of Chinese medicine (CM) in different diseases with the same treatment.

METHODS

A text mining approach was adopted to analyze the commonalities between RA and DM according to CM and biological elements. The major commonalities were subsequently verified in RA and DM rat models, in which herbal formula for the treatment of both RA and DM identified via text mining was used as the intervention.

RESULTS

Similarities were identified between RA and DM regarding the CM approach used for diagnosis and treatment, as well as the networks of biological activities affected by each disease, including the involvement of adhesion molecules, oxidative stress, cytokines, T-lymphocytes, apoptosis, and inflammation. The Ramulus Cinnamomi-Radix Paeoniae Alba-Rhizoma Anemarrhenae is an herbal combination used to treat RA and DM. This formula demonstrated similar effects on oxidative stress and inflammation in rats with collagen-induced arthritis, which supports the text mining results regarding the commonalities between RA and DM.

CONCLUSION

Commonalities between the biological activities involved in RA and DM were identified through text mining, and both RA and DM might be responsive to the same intervention at a specific stage.

Iridoid glycosides from the flowers of Gentiana macrophylla Pall. ameliorate collagen-induced arthritis in rats

BACKGROUND

The flowers of Gentiana macrophylla have been usually applied to cure the joint inflammation and rheumatoid arthritis in Traditional Chinese Medicine.

HYPOTHESIS/PURPOSE

This work aimed to investigate the anti-rheumatoid arthritic effect and possible mechanism of iridoid glycosides from G. macrophylla (GMI) using an animal model of collagen-induced rheumatoid arthritis (CIA) in rats.

STUDY DESIGN

All rats were randomly divided into five groups: normal control, CIA, dexamethasone, 15mg/kg and 30mg/kg GMI.

METHODS

CIA was induced (day 0) in male Sprague-Dawley rats by intradermal injection of complete Bovine CII at the base of the tail. Dexamethasone was chosen as the positive drug. The administration of different drugs started from day 1 and continued for 28 days. Paw swelling, arthritis score and histopathological changes were examined to assess the severity of arthritis. In addition, the serum levels of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions in joint synovial tissues were detected.

RESULTS

GMI reduced paw edema, arthritis scores and the index of spleen and thymus from day 7 to 21 after CIA compared with those in the CIA group. Our data also demonstrated that GMI inhibited pro-inflammatory cytokines such as TNF-α, IL-1β and IL-6, regulated the expression of iNOS and COX-2 compared with those in the CIA group. We also obtained four major components from GMI, identified as loganic acid, swertamarin, gentiopicroside and sweroside, and the contents of them were also calculated respectively.

CONCLUSION

Taken together, our results shed light on the therapeutic efficacy of GMI in rats rheumatoid arthritis model by reducing the levels of IL-1β, IL-6 and TNF-α in serum as well as down-regulating the levels of iNOS and COX-2. Therefore, GMI may be an effective therapy for the treatment of rheumatoid arthritis.

Puerarin for ischaemic stroke

BACKGROUND

Puerarin, a form of herbal medicine, is widely used in the treatment of ischaemic stroke in China.

OBJECTIVES

To assess the effects of puerarin in people with ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register and the Chinese Stroke Trials Register (last searched August 2015). In addition, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 7), MEDLINE (1948 to August 2015), EMBASE (1980 to August 2015), AMED (the Allied and Complementary Medicine Database, 1985 to August 2015) and the China Biological Medicine Database (CBM-disc 1979 to August 2015). We searched reference lists, relevant clinical trials and research registers and contacted pharmaceutical companies and researchers in an effort to identify further published and unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-randomised controlled clinical trials comparing puerarin with placebo or open control (no placebo) in people with ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, and extracted the data.

MAIN RESULTS

We included 20 RCTs with 1574 participants in this updated review. All trials were published in Chinese language journals. We included 14 trials that we had excluded in the previous version of the review after we added a new outcome in this update. Time windows within which the participants were randomised ranged from 4.5 hours to 10 days. Ischaemic stroke was confirmed by computerised tomography (CT) or magnetic resonance imaging (MRI) in 18 trials. Meta-analysis of two trials with 164 participants showed that treatment with puerarin did not reduce death or dependency at final follow-up (RR 0.79, 95% CI 0.45 to 1.36). One trial with 83 participants reported that the mean value of the Barthel Index in the puerarin group was below that in the control group. Meta-analysis of 16 trials with 1305 participants showed that puerarin reduced the proportion of participants without improvement of neurological deficit at the end of follow-up (RR 0.42, 95% CI 0.33 to 0.55). None of the included trials reported serious adverse effects.The quality of evidence was low due to incomplete reporting of the methods and short-term follow-up.

AUTHORS' CONCLUSIONS

There is not enough evidence to evaluate the effect of puerarin on survival or dependency in people with ischaemic stroke. High quality and large-scale RCTs with long-term follow-up are needed to assess its efficacy.

Puerarin attenuates severe burn-induced acute myocardial injury in rats

BACKGROUND

Puerarin, the main isoflavone glycoside extracted from the root of Pueraria lobata, is widely prescribed for patients with cardiovascular disorders in China. This study investigates the effect of puerarin on severe burn-induced acute myocardial injury in rats and its underlying mechanisms.

MATERIALS AND METHODS

Healthy adult Wistar rats were divided into three groups: (1) sham group, sham burn treatment; (2) burn group, third-degree burns over 30% of the total body surface area (TBSA) with lactated Ringer's solution for resuscitation; and (3) burn plus puerarin group, third-degree burns over 30% of TBSA with lactated Ringer's solution containing puerarin for resuscitation. The burned animals were sacrificed at 1, 3, 6, 12, and 24 h after burn injury. Myocardial injury was evaluated by analyzing serum creatine kinase MB fraction (CK-MB) activity and cardiac troponin T (cTNT) level. Changes in cardiomyocyte ultrastructure were also determined using a transmission electron microscope. Tumor necrosis factor (TNF)-α concentration in serum was measured by radioimmunoassay. Cardiac myeloperoxidase (MPO) activity and malondialdehyde (MDA) concentration were measured to determine neutrophil infiltration and oxidative stress in the heart, respectively. The expression of p38 mitogen-activated protein (MAP) kinase in the heart was determined by Western blot analysis.

RESULTS

After the 30% TBSA full-thickness burn injury, serum CK-MB activities and cTnT levels increased markedly, both of which were significantly decreased by the puerarin treatment. The level of serum TNF-α concentration in burn group at each time-point was obviously higher than those in sham group (1.09±0.09 ng/ml), and it reached the peak value at 12 h post burn. Burn trauma also resulted in worsen ultrastructural condition, elevated MPO activity and MDA content in heart tissue, and a significant activation of cardiac p38 MAP kinase. Administration of puerarin improved the ultrastructural changes in cardiomyocytes, decreased TNF-α concentration in serum as well as suppressed cardiac MPO activity and reduced MDA content, and abolished the activation of p38 MAP kinase in heart tissue after severe burn.

CONCLUSIONS

These results suggest that puerarin attenuates inflammatory responses, reduces neutrophil infiltration and oxidative stress in the heart, and protects against acute myocardial injury induced by severe burn.

Intervening TNF-α via PPARγ with Gegenqinlian Decoction in Experimental Nonalcoholic Fatty Liver Disease

This paper is to explore the effect and mechanism of Gegenqinlian decoction on experimental nonalcoholic fatty liver disease (NAFLD) in vivo and in vitro. The final aim is to make clear whether Gegenqinlian decoction would impact NAFLD through improving PPARγ to suppress inflammation and regulate lipid. The data in this research suggested that Gegenqinlian decoction is a potent way to manage NAFLD through improving PPARγ to regulate lipid and suppress inflammation.

Puerarin protects against damage to spatial learning and memory ability in mice with chronic alcohol poisoning

We evaluated the effect of puerarin on spatial learning and memory ability of mice with chronic alcohol poisoning. A total of 30 male C57BL/6 mice were randomly divided into model, puerarin, and control groups (n=10 each). The model group received 60% (v/v) ethanol by intragastric administration followed by intraperitoneal injection of normal saline 30 min later. The puerarin group received intragastric 60% ethanol followed by intraperitoneal puerarin 30 min later, and the control group received intragastric saline followed by intraperitoneal saline. Six weeks after treatment, the Morris water maze and Tru Scan behavioral tests and immunofluorescence staining of cerebral cortex and hippocampal neurons (by Neu-N) and microglia (by Ib1) were conducted. Glutamic acid (Glu) and gamma amino butyric acid (GABA) in the cortex and hippocampus were assayed by high-performance liquid chromatography (HPLC), and tumor necrosis factor (TNF)-α and interleukin (IL)-1β were determined by ELISA. Compared with mice in the control group, escape latency and distance were prolonged, and spontaneous movement distance was shortened (P<0.05) by puerarin. The number of microglia was increased in both the cortex and hippocampal dentate gyrus (P<0.01), and neurons were reduced only in the hippocampal dentate gyrus (P<0.01) in puerarin-treated mice. In the model group, Glu and GABA levels decreased (P<0.05), and Glu/GABA, TNF-α, and IL-1β increased (P<0.01) with puerarin treatment, returning to near normal levels. In conclusion, puerarin protected against the effects of chronic alcohol poisoning on spatial learning and memory ability primarily because of anti-inflammatory activity and regulation of the balance of Glu and GABA.

Progress on the pharmacological research of puerarin: a review

Contemporary pharmacological research has demonstrated that puerarin, the most important phytoestrogen extracted from Pueraria lobata(Willd.) Ohwi, has protecting functions on the cardiovascular system, nervous system, osteoporosis, liver injury, and inflammation in vivo and in vitro. Most of these research studies focused on inhibiting oxidative stress and apoptosis through regulating various bioactivators and signal pathways. Among these, superoxide dismutase (SOD), endothelial nitric oxide synthase (eNOS) and malondialdehyde (MDA), and PI3K/Akt, MAPK, and NF-κB are of great importance. The data cited in this review were mainly obtained from articles listed in PubMed and Elsevier SDOL published from 1959 to 2013, and the search term used was "puerarin".

Mucoadhesive microparticles for gastroretentive delivery: preparation, biodistribution and targeting evaluation

The aim of this research was to prepare and characterize alginate-chitosan mucoadhesive microparticles containing puerarin. The microparticles were prepared by an emulsification-internal gelatin method using a combination of chitosan and Ca²⁺ as cationic components and alginate as anions. Surface morphology, particle size, drug loading, encapsulation efficiency and swelling ratio, in vitro drug released, in vitro evaluation of mucoadhesiveness and Fluorescence imaging of the gastrointestinal tract were determined. After optimization of the formulation, the encapsulation efficiency was dramatically increased from 70.3% to 99.2%, and a highly swelling ratio was achieved with a change in particle size from 50.3 ± 11.2 μm to 124.7 ± 25.6 μm. In ethanol induced gastric ulcers, administration of puerarin mucoadhesive microparticles at doses of 150 mg/kg, 300 mg/kg, 450 mg/kg and 600 mg/kg body weight prior to ethanol ingestion significantly protected the stomach ulceration. Consequently, significant changes were observed in inflammatory cytokines, such as prostaglandin E₂ (PGE₂), tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and interleukin1β (IL-1β), in stomach tissues compared with the ethanol control group. In conclusion, core-shell type pH-sensitive mucoadhesive microparticles loaded with puerarin could enhance puerarin bioavailability and have the potential to alleviate ethanol-mediated gastric ulcers.

Petroleum ether extractive of the hips of Rosa multiflora ameliorates collagen-induced arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The hip of Rosa multiflora Thunb. (HRM) has been traditionally used as a dietary supplement and a herbal remedy for the treatment of various diseases, including inflammation, osteoarthritis, rheumatoid arthritis and chronic pain, in China. The current study was to evaluate the therapeutic efficacy of the petroleum ether extractive of HRM (PEE) on type II collagen-induced rheumatoid arthritis (CIA) in male Wistar rats. In addition, the anti-inflammatory mechanism(s) of PEE on type II CIA was explored.

MATERIALS AND METHODS

Rheumatoid arthritis (RA) was induced by intradermal injection of bovine type II collagen on Day 1 and Day 8. Starting from Day 13, normal rats were treated with vehicle (serving as the control group); the CIA rats were treated with vehicle (CIA group), dexamethasone (0.25mg/kg bw per day, p.o.) (a positive control), lei-gong-teng (LGT: 10mg/kg bw per day, p.o.) (a clinically used Chinese patent medicine in RA therapy) or PEE (12, 36 or 120mg/kg bw per day, p.o.) for 28 days.

RESULTS AND CONCLUSIONS

PEE (120mg/kg bw per day) efficiently attenuated the severity of arthritis in the CIA rats by reducing the mean arthritis severity scores and the fore/hind paw swelling as well as reduced histological changes by decreasing the cartilage surface erosion and cartilage proteoglan depletion. PEE׳s therapeutic effect in RA may involve the inhibition of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6, in serum and/or the elevation of the activities of hepatic anti-oxidative enzymes including SOD, CAT and GSH-Px. However, the detailed anti-inflammatory mechanism, the main effective components and the interaction between different ingredients in PEE are still not clear and require more studies.

Antioxidant effects of Genkwa flos flavonoids on Freund׳s adjuvant-induced rheumatoid arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Genkwa flos (Daphne genkwa Sieb. et Zucc.), a Chinese herbal medicine, has been traditionally used for over two thousand years in China for inflammation related symptoms, including joint pain. To evaluate the antioxidative effects of flavonoid aglycones (FA) isolated from Genkwa flos on adjuvant arthritis in rats and to identify the relationship between antioxidant potential and whole blood viscosity (WBV).

MATERIALS AND METHODS

FA compounds were identified using LC-MS and the content was assayed by HPLC. Arthritis was induced by an intradermal injection of Freund׳s complete adjuvant in the footpad. The effects of FA on paw volumes, secondary arthritis scores, histopathology of joints, and body and organ weights were measured. The antioxidant effects of FA and WBV were determined.

RESULTS

LC-MS analysis showed that the FA contained four major compounds: luteolin, apigenin, hydroxygenkwanin and genkwanin. FA significantly decreased paw edema, arthritis scores, and weight loss. These observations were consistent with the reduction of oxidative stress and the improvement of the WBV.

CONCLUSION

FA significantly decreased arthritis in a rat model through antioxidant and hemorheological modulatory mechanisms. The Genkwa flos flavonoids may have clinical potential for the treatment of rheumatoid arthritis.

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 protects against Staphylococcus aureus-induced injury of human alveolar epithelial A549 cells via downregulating alpha-hemolysin secretion

Alpha-hemolysin, a secreted pore-forming toxin, plays an indispensable role in the pathogenicity of Staphylococcus aureus. In this study, the antimicrobial activity of puerarin against S. aureus was investigated; as a result, puerarin showed no influence on the growth of this organism. However, hemolysis and western blotting assays showed that puerarin concentration dependently inhibited the secretion of alpha-hemolysin at low concentrations. Real-time RT-PCR assay was further employed to evaluate the transcriptional level of hla, the gene encoding alpha-hemolysin, and RNAIII, an effector molecule of the agr system. The results indicated that the RNAIII expression and subsequent hla transcription were also inhibited by puerarin in a dose-dependent manner. Furthermore, puerarin significantly prevented human alveolar epithelial A549 cells from S. aureus-induced injury. Thereby, puerarin may be considered as a potential candidate for the development of antivirulence drugs in the treatment of S. aureus-mediated infections.

LC-MS/MS method for the determination of a new puerarin derivative and its application in pharmacokinetic studies in rats

AIM

To establish a sensitive and rapid liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method for the quantitative analysis of dehydrated puerarin in rat plasma, and its application for pharmacokinetic studies.

METHODS

A plasma sample was pretreated by one-step protein precipitation by the addition of five volumes of methanol. The chromatographic separation was achieved on a Zorbax SB-C18 column (4.6 mm × 150 mm I.D. 5.0 μm, Agilent, USA) at 40 °C at a flow rate of 0.6 mL·min(-1) by an isocratic elution consisting of 10 mmol·L(-1) ammonium acetate in methanol and water containing 0.1% formic acid in a ratio of 20 : 80 (V/V). Detection was performed on a triple quadrupole mass spectrometer in multiple-reaction monitoring (MRM) mode. An atmospheric pressure chemical ionization (APCI) interface in positive ionization mode was used by monitoring the transitions from m/z 399.1→281.0 (dehydrated puerarin) and m/z 271.0→215.0 (internal standard, IS).

RESULTS

Calibration curves were linear in the concentration range from 1.50 to 5400 ng·mL(-1), and the lower limit of quantification (LLOQ) was 1.50 ng·mL(-1) in rat plasma. The accuracy and precision values, which were calculated from three different sets of quality control samples analyzed in sextuplicate on three different days, ranged from 95.73% to 103.18%, and from 4.33% to 7.86%, respectively.

CONCLUSION

The method was successfully applied to assess the pharmacokinetics of dehydrated puerarin after oral administration in rats.

Comparison between the efficacies of curcumin and puerarin in C57BL/6 mice with steatohepatitis induced by a methionine- and choline-deficient diet

Non-alcoholic fatty liver disease (NAFLD) is a prevalent disease, which features an abnormal accumulation of lipids inside hepatocytes. Steatohepatitis plays a critical role in the process resulting in liver fibrosis and cirrhosis. Curcumin and puerarin are herbal products widely used in Asia, which are believed to have therapeutic benefits for alleviating the symptoms of steatohepatitis. In this study, mice models of steatohepatitis induced by a methionine- and choline-deficient diet (MCD) were established to compare the pharmacological actions of curcumin and puerarin. The results showed that curcumin and puerarin exerted inhibitory effects against MCD-induced steatohepatitis in mice. Briefly, curcumin and puerarin significantly downregulated the levels of tumor necrosis factor-α in the blood serum of mice (P<0.01, versus the MCD group). In addition, the levels of triglycerides, total cholesterol and low density lipoproteins in the serum were significantly reduced by puerarin treatment (P<0.05, versus the MCD group). The concentration of interleukin-6 was downregulated by curcumin only (P<0.01, versus the MCD group). Curcumin and puerarin significantly increased the levels of peroxisome proliferator-activated receptor-γ (PPARγ; P<0.05, versus the MCD group). Moreover, increased nuclear factor-κB (NF-κB) was markedly attenuated by curcumin (P<0.05, versus the MCD group). In conclusion, curcumin and puerarin appear to exert different actions against steatohepatitis. It is possible that puerarin regulated lipid metabolism in the ‘first hit’ stage through the PPARγ pathway, while curcumin inhibited the inflammatory response in the ‘second hit’ stage through the NF-κB pathway.

The Aqueous Extract of Rhizome of Gastrodia elata Protected Drosophila and PC12 Cells against Beta-Amyloid-Induced Neurotoxicity

This study aims to investigate the neuroprotective effect of the rhizome of Gastrodia elata (GE) aqueous extract on beta-amyloid(Aβ)-induced toxicity in vivo and in vitro. Transgenic Drosophila mutants with Aβ-induced neurodegeneration in pan-neuron and ommatidia were used to determine the efficacy of GE. The antiapoptotic and antioxidative mechanisms of GE were also studied in Aβ-treated pheochromocytoma (PC12) cells. In vivo studies demonstrated that GE (5 mg/g Drosophila media)-treated Drosophila possessed a longer lifespan, better locomotor function, and less-degenerated ommatidia when compared with the Aβ-expressing control (all P < 0.05). In vitro studies illustrated that GE increased the cell viability of Aβ-treated PC12 cells in dose-dependent manner, probably through attenuation of Aβ-induced oxidative and apoptotic stress. GE also significantly upregulated the enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase, leading to the decrease of reactive oxidation species production and apoptotic marker caspase-3 activity. In conclusion, our current data presented the first evidence that the aqueous extract of GE was capable of reducing the Aβ-induced neurodegeneration in Drosophila, possibly through inhibition of apoptosis and reduction of oxidative stress. GE aqueous extract could be developed as a promising herbal agent for neuroprotection and novel adjuvant therapies for Alzheimer's disease.

A herbal formula containing roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) inhibits inflammatory mediators in LPS-stimulated RAW 264.7 macrophages through inhibition of nuclear factor κB (NFκB) pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The herbal formula DG, containing roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen), has long history in treating cardiovascular diseases. It has been shown to be able to reduce intima-media thickening in coronary patients in our previous clinical study. Since intima-media thickening is the hallmark of atherosclerotic disease, the etiology of which is inflammation of the arterial wall, the mechanism underlying the effect of DG may be related to its anti-inflammatory activities.

AIM OF STUDY

The present study aims to determine the anti-inflammatory activity of DG and elucidate its underlying mechanisms with regards to its molecular basis of action.

MATERIALS AND METHOD

The anti-inflammatory effect of DG was studied by using lipopolysaccharide (LPS)-stimulated activation of nuclear factor κB (NFκB) pathway and subsequent production of inflammatory mediators, including nitric oxide (NO), prostaglandin E(2) (PGE(2)), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and macrophage chemotactic protein-1 (MCP-1), in mouse RAW 264.7 macrophages.

RESULTS

The present study demonstrated that DG could suppress the production of NO and PGE(2) through the inhibition of iNOS and COX-2 genes. DG could also inhibit the production of IL-1β, IL-6 and MCP-1, but not TNF-α, through the inhibition of respective mRNA expressions. Further investigations showed the inhibitory effect of DG on activation of IKKα/β and degradation of IκBα, thus preventing nuclear translocation of NFκB. All these results suggested the inhibitory effects of DG on the production of inflammatory mediators through the inhibition of the NFκB pathway.

CONCLUSIONS

The inhibitory effects of DG on the production of inflammatory mediators by LPS-stimulated RAW 264.7 macrophages, are accomplished by inhibiting the nuclear translocation of NFκB through inactivating IKKα/β and preventing degradation of IκBα.

In vitro and in vivo anticancer activity of a novel puerarin nanosuspension against colon cancer, with high efficacy and low toxicity

The present study aims to evaluate the anticancer activity of puerarin nanosuspensions in human colon cancer HT-29 cell line in vitro and in vivo. Puerarin nanosuspensions were prepared by the high-pressure homogenization (HPH) technique. The HT-29 cells were incubated with increasing concentrations of puerarin solution and nanosuspensions for indicated times. MTT evaluated cellular viability and investigated the effect of puerarin on cell proliferation of HT-29. Annexin V-FITC/PI staining method was conducted to determine the influences of the puerarin nanosuspensions on cell cycle and apoptosis. The in vivo anticancer activity of the puerarin nanosuspensions was observed in HT-29 cancer bearing mice. The puerarin nanosuspensions were well re-dispersed in aqueous media a mean diameter about 400-500 nm. Cytotoxicity assay, observation of morphological changes and early apoptosis revealed that the puerarin nanosuspensions could significantly enhance the in vitro anti-proliferation against HT-29 cells compared to the puerarin free solution. The prepared puerarin nanosuspensions in vivo evaluation showed higher anticancer efficacy and lower toxicity compared to the free solution, as shown by changes in tumor volumes, body weights, and survival rates. Based on these data, the potential of the puerarin nanosuspensions to serve as a cancer chemotherapeutic agent for colon cancer could be suggested.

Puerarin stimulates osteoblasts differentiation and bone formation through estrogen receptor, p38 MAPK, and Wnt/β-catenin pathways

Puerarin is an isoflavone extracted from Radix Puerariae, a traditional Chinese herb used to treat many diseases such as osteoporosis. In this study, puerarin was shown to stimulate alkaline phosphatase (ALP) activity, type I collagen (Col I) secretion, and mineralized nodules formation of primary osteoblasts. Whereas the estrogen receptor (ER) antagonist ICI 182780 was able to reduce the increase in ALP activity and Col I secretion induced by puerarin. Furthermore, puerarin was shown to elevate levels of phospho-p38 mitogen-activated protein kinase (MAPK) and β-catenin proteins in a time-dependent manner. Pretreatment of osteoblasts with ICI 182780 can reduce this elevation, whereas pretreatment with p38 MAPK inhibitor SB 203580 did not affect the increase of β-catenin protein. Meanwhile, intragastric administration of puerarin protected against reduction in bone mineral density and bone mineral content in ovariectomized rats, and improved femur trabecular bone structure. Taken together, ER, p38 MAPK, and Wnt/β-catenin pathways were involved in puerarin-stimulated osteoblasts differentiation and bone formation.

Phenol acidity and ease of oxidation in isoflavonoid/β-carotene antioxidant synergism

Regeneration of β-carotene from the β-carotene radical cation by the 4'-propylpuerarin anion (second-order rate constant=1.5×10(9) L mol(-1) s(-1) in methanol/chloroform=1:9 (v/v) solution at 25 °C as determined by laser flash photolysis) was found to be marginally slower than regeneration by the 7-propylpuerarin anion (2.3×10(9) L mol(-1) s(-1)), in agreement with the 7-propylpuerarin anion being more reducing (E'=0.56 V vs NHE) than the 4'-propylpuerarin anion (E'=1.01 V vs NHE). The potentials were calculated from E°=1.12 and 1.44 V (vs NHE) as determined by cyclic voltametry in aqueous solution and pKa=9.51 and 7.23 obtained previously for 7-propylpuerarin and 4'-propylpuerarin, respectively. The less reducing but more acidic 4'-propylpuerarin showed less antioxidant activity in liposome of pH 7.4, but more significant antioxidant synergism with β-carotene than the more reducing but less acidic 7-propylpuerarin for oxidation initiated in the liposome lipid phase. Electrostatic effects are concluded to be important in the regeneration of β-carotene from the radical cation in the water/lipid interface because approximately 50% of 4'-propylpuerarin is present as the anion, whereas only 0.5% of 7-propylpuerarin is present as the anion. In contrast, penetration of the undissociated phenolic group into the lipid phase, more significant for 7-propylpuerarin than for 4'-propylpuerarin according to the calculated water/lipid partition coefficients, becomes important for the chain-breaking action in lipid oxidation of the puerarin derivatives as models for (iso)flavonoids and their glycosides.