Puerarin attenuates smoke inhalation injury by regulation of Th1/Th2 expression and inhibition of Th17 cells in rats

Effect of natural polyphenols in Chinese herbal medicine on obesity and diabetes: Interactions among gut microbiota, metabolism, and immunity

With global prevalence, metabolic diseases, represented by obesity and type 2 diabetes mellitus (T2DM), have a huge burden on human health and medical expenses. It is estimated that obese population has doubled in recent 40 years, and population with diabetes will increase 1.5 times in next 25 years, which has inspired the pursuit of economical and effective prevention and treatment methods. Natural polyphenols are emerging as a class of natural bioactive compounds with potential beneficial effects on the alleviation of obesity and T2DM. In this review, we investigated the network interaction mechanism of "gut microbial disturbance, metabolic disorder, and immune imbalance" in both obesity and T2DM and systemically summarized their multiple targets in the treatment of obesity and T2DM, including enrichment of the beneficial gut microbiota (genera Bifidobacterium, Akkermansia, and Lactobacillus) and upregulation of the levels of gut microbiota-derived metabolites [short-chain fatty acids (SCFAs)] and bile acids (BAs). Moreover, we explored their effect on host glucolipid metabolism, the AMPK pathway, and immune modulation via the inhibition of pro-inflammatory immune cells (M1-like Mϕs, Th1, and Th17 cells); proliferation, recruitment, differentiation, and function; and related cytokines (TNF-α, IL-1β, IL-6, IL-17, and MCP-1). We hope to provide evidence to promote the clinical application of natural polyphenols in the management of obesity and T2DM.

Puerarin: A Potential Therapeutic for SARS-CoV-2 and Hantavirus Co-Infection

Patients with Hantavirus-caused epidemic hemorrhagic fever (EHF) are at risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there is currently no validated EHF/SARS-CoV-2 strategy. Several studies have recently shown Puerarin, a natural product, has potent antiviral properties. The goal of present study was to determine the mechanism of puerarin in patients with EHF/COVID-19. We use network pharmacology and bioinformatics to investigate the possible pharmacological targets, bioactivities, and molecular mechanisms of puerarin in the treatment of patients with EHF/SARS-CoV-2. The study investigated the pathogenesis of COVID-19 and EHF and the signaling pathway impacted by puerarin. 68 common genes linked to puerarin and EHF/SARS-CoV-2 were discovered during the investigation. By using protein-protein interaction (PPI) network, we identified RELA, JUN, NF-B1, NF-B2, and FOS as potential therapeutic targets. The bioactivity and signaling pathways of puerarin have also been demonstrated in the treatment of EHF and COVID-19. According to present study, puerarin could reduce excessive immune responses and inflammation through the NF-B, TNF, and HIF-1 signaling pathways. This study explored the potential therapeutic targets and mechanisms of Puerarin in the treatment of EHF/COVID-19.

Potential therapeutic interventions of plant-derived isoflavones against acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that possibly leads to high morbidity and mortality as no therapy exists. Several natural ingredients with negligible adverse effects have recently been investigated to possibly inhibit the inflammatory pathways associated with ALI at the molecular level. Isoflavones, as phytoestrogenic compounds, are naturally occurring bioactive compounds that represent the most abundant category of plant polyphenols (Leguminosae family). A broad range of therapeutic activities of isoflavones, including antioxidants, chemopreventive, anti-inflammatory, antiallergic and antibacterial potentials, have been extensively documented in the literature. Our review exclusively focuses on the possible anti-inflammatory, antioxidant role of botanicals'-derived isoflavones against ALI and their immunomodulatory effect in experimentally induced ALI. Despite the limited scope covering their molecular mechanisms, isoflavones substantially contributed to protecting from ALI via inhibiting toll-like receptor 4 (TLR4)/Myd88/NF-κB pathway and subsequent cytokines, chemokines, and adherent proteins. Nonetheless, future research is suggested to fill the gap in elucidating the protective roles of isoflavones to alleviate ALI concerning antioxidant potentials, inhibition of the inflammatory pathways, and associated molecular mechanisms.

Puerarin exhibits antiinflammatory properties in gunpowder smog-induced acute lung injury in rats via regulation of the renin-angiotensin system and the NFκB signaling pathway

Puerarin, which is a widely used in Traditional Chinese Medicine, was previously demonstrated to regulate the subsets of CD4⁺ lymphocytes in gunpowder smog-induced acute lung injury (ALI). However, the underlying mechanism remains largely unknown. Previous studies on autoimmune diseases have revealed that the renin-angiotensin system (RAS) and NF-κB participate in regulating the levels of CD4⁺ T lymphocytes. The aim of the present study was to further investigate the mechanisms underlying the protective effects of puerarin. Wistar rats were randomly divided into four groups as follows: Normal control, puerarin control, smoke inhalation injury and puerarin treatment plus smoke inhalation injury groups. The levels of angiotensin II (Ang II) in lung tissue and in the circulation, and the levels of interleukin (IL)-6, IL-1β, IL-17A and tumor necrosis factor (TNF)-α in the bronchoalveolar lavage fluid (BALF) were assayed using ELISA kits. The expression of Ang II type 1 receptor (AT1-R), angiotensin-converting enzyme (ACE) and ACE2 were examined by immunohistochemical analysis and western blotting. Phosphorylated (p-) NF-κB p65 and NF-κB inhibitor α (IκB-α) protein expression levels were also determined using western blotting. Puerarin treatment reduced the levels of inflammatory cytokines in the BALF. Furthermore, puerarin treatment significantly decreased the levels of Ang II, AT1-R and ACE, which were increased following smoke inhalation. Conversely, puerarin treatment upregulated the expression of ACE2, which was downregulated following smoke inhalation. Additionally, puerarin decreased the expression of p-NF-κB p65 and increased that of IkB-α. Thus, the antiinflammatory effects of puerarin were partly mediated via the RAS and via regulation of the NFĸB signaling pathway in rats with gunpowder smog-induced ALI.

Gegen Qinlian decoction relieved DSS-induced ulcerative colitis in mice by modulating Th17/Treg cell homeostasis via suppressing IL-6/JAK2/STAT3 signaling

BACKGROUND

Gegen Qinlian decoction (GQ) is a traditional Chinese herbal prescription that has been widely used for the treatment of bacterial dysentery and enteric typhoid fever. Recently, GQ has been clinically reported to be a potential candidate for the treatment of ulcerative colitis (UC). However, the immunoregulatory function of GQ in the treatment of UC has not been fully elucidated.

PURPOSE

This study focused on the role of immune imbalance in the pathogenesis of UC and the immunomodulatory effect of GQ in the treatment of UC.

METHODS

The UC model was established by treating female mice with 3.0% dextran sulfate sodium (DSS) for 7 days, and GQ was orally administered at dosages of 1.5 and 7.5 g/kg/day. Inflammatory factors were detected by ELISA and qRT-PCR. Treg and Th17 cell dysregulation was analyzed by qRT-PCR, immunohistochemistry and flow cytometry. Proteins related to IL-6/JAK2/STAT3 signaling were detected by western blotting.

RESULTS

GQ significantly alleviated the symptoms of UC mice and suppressed the activity of myeloperoxidase (MPO). Furthermore, the production of proinflammatory factors, such as IL-1β, TNF-α and IL-6, was dramatically reduced after GQ administration. Furthermore, GQ improved the infiltration of Treg and Th17 cells into the colons and decreased the expression of inflammatory factors, such as TGF-β1 and IL-17. The frequencies of Treg and Th17 cells in the Peyer's patches and spleen were reduced by GQ administration; however, GQ had no significant regulatory effect on normal mice. The western blotting results showed that GQ markedly suppressed the phosphorylation of JAK2 and STAT3 and decreased the transcription function of phosphorylated STAT3.

CONCLUSIONS

Taken together, these results indicated that GQ alleviated DSS-induced UC by suppressing IL-6/JAK2/STAT3 signaling to restore Treg and Th17 cell homeostasis in colonic tissue.

Natural products as modulators of retinoic acid receptor-related orphan receptors (RORs)

Covering: 1994 to 2020 Retinoic acid receptor-related orphan receptors (RORs) belong to a subfamily of the nuclear receptor superfamily and possess prominent roles in circadian rhythm, metabolism, inflammation, and cancer. They have been subject of research for over two decades and represent attractive but challenging drug targets. Natural products were among the first identified ligands of RORs and continue to be of interest to this day. This review focuses on ligands and indirect modulators of RORs from natural sources and explores their roles in a therapeutic context.

Puerarin protects against myocardial ischemia/reperfusion injury by inhibiting inflammation and the NLRP3 inflammasome: The role of the SIRT1/NF-κB pathway

AIMS

The purpose of this study was to investigate the protective effects of puerarin and elucidate the underlying mechanisms of puerarin in myocardial ischemia/reperfusion (MI/R) injury.

MAIN METHODS

C57BL/6 mice were exposed to puerarin (100 mg/kg) with or without the SIRT1 inhibitor nicotinamide (500 mg/kg) and then subjected to MI/R operation. Myocardial infarct size, serum creatine kinase-MB (CK-MB) activity, apoptotic cell death, and cardiac structure and function were examined to evaluate MI/R injury. RT-PCR and western blotting were used to determine the inflammatory response and inflammasome activation, as well as activation of SIRT1/NF-κB pathway.

RESULTS

Puerarin significantly reduced myocardial infarct size, serum CK-MB activity, and apoptotic cell death, and improved cardiac structural damage and dysfunction. Moreover, puerarin notably decreased the mRNA and protein levels of TNF-α, IL-6, and IL-1β, indicating that puerarin attenuated MI/R-induced inflammation. Furthermore, puerarin markedly decreased the protein levels of Ac-NF-κB, NLRP3, cleaved caspase-1, cleaved IL-1β, and cleaved IL-18 and increased the protein level of SIRT1. More importantly, the SIRT1 inhibitor nicotinamide prevented these puerarin-induced cardioprotective effects and regulation of the SIRT1/NF-κB pathway, as well as the NLRP3 inflammasome activation.

CONCLUSION

Puerarin protected against MI/R injury by inhibiting inflammatory responses probably via the SIRT1/NF-κB pathway, and inhibition of the NLRP3 inflammasome was also involved in puerarin-induced cardioprotective effects. These results suggest that puerarin may be a novel candidate for the treatment of ischemic heart disease.

A comparative study of a preclinical survival model of smoke inhalation injury in mice and rats

Smoke inhalation injury increases morbidity and mortality. Clinically relevant animal models are necessary for the continued investigation of the pathophysiology of inhalation injury and the development of therapeutics. The goal of our research was threefold: 1) to develop a reproducible survival model of smoke inhalation injury in rats that closely resembled our previous mouse model, 2) to validate the rat smoke inhalation injury model using a variety of laboratory techniques, and 3) to compare and contrast our rat model with both the well-established mouse model and previously published rat models to highlight our improvements on smoke delivery and lung injury. Mice and rats were anesthetized, intubated, and placed in custom-built smoke chambers to passively inhale woodchip-generated smoke. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected for confirmatory tests. Lung sections were hematoxylin and eosin stained, lung edema was assessed with wet-to-dry (W/D) ratio, and inflammatory cell infiltration and cytokine elevation were evaluated using flow cytometry, immunohistochemistry, and ELISA. We confirmed that our mouse and rat models of smoke inhalation injury mimic the injury seen after human burn inhalation injury with evidence of pulmonary edema, neutrophil infiltration, and inflammatory cytokine elevation. Interestingly, rats mounted a more severe immunological response compared with mice. In summary, we successfully validated a reliable and clinically translatable survival model of lung injury and immune response in rats and mice and characterized the extent of this injury. These animal models allow for the continued study of smoke inhalation pathophysiology to ultimately develop a better therapeutic.

Emerging therapies for smoke inhalation injury: a review

Background

Smoke inhalation injury increases overall burn mortality by up to 20 times. Current therapy remains supportive with a failure to identify an optimal or targeted treatment protocol for smoke inhalation injury. The goal of this review is to describe emerging therapies that are being developed to treat the pulmonary pathology induced by smoke inhalation injury with or without concurrent burn injury.

Main body

A comprehensive literature search was performed using PubMed (1995–present) for therapies not approved by the U.S. Food and Drug Administration (FDA) for smoke inhalation injury with or without concurrent burn injury. Therapies were divided based on therapeutic strategy. Models included inhalation alone with or without concurrent burn injury. Specific animal model, mechanism of action of medication, route of administration, therapeutic benefit, safety, mortality benefit, and efficacy were reviewed. Multiple potential therapies for smoke inhalation injury with or without burn injury are currently under investigation. These include stem cell therapy, anticoagulation therapy, selectin inhibition, inflammatory pathway modulation, superoxide and peroxynitrite decomposition, selective nitric oxide synthase inhibition, hydrogen sulfide, HMG-CoA reductase inhibition, proton pump inhibition, and targeted nanotherapies. While each of these approaches shows a potential therapeutic benefit to treating inhalation injury in animal models, further research including mortality benefit is needed to ensure safety and efficacy in humans.

Conclusions

Multiple novel therapies currently under active investigation to treat smoke inhalation injury show promising results. Much research remains to be conducted before these emerging therapies can be translated to the clinical arena.

Preclinical and clinical studies of smoke-inhalation-induced acute lung injury: update on both pathogenesis and innovative therapy

Smoke-inhalation-induced acute lung injury (SI-ALI) is a leading cause of morbidity and mortality in victims of fire tragedies. SI-ALI contributes to an estimated 30% of burn-caused patient deaths, and recently, more attention has been paid to the specific interventions for this devastating respiratory illness. In the last decade, much progress has been made in the understanding of SI-ALI patho-mechanisms and in the development of new therapeutic strategies in both preclinical and clinical studies. This article reviews the recent progress in the treatment of SI-ALI, based on pathophysiology, thermal damage, airway obstruction, the nuclear-factor kappa-B signaling pathway, and oxidative stress. Preclinical therapeutic strategies include use of mesenchymal stem cells, hydrogen sulfide, peroxynitrite decomposition catalysts, and proton-pump inhibitors. Clinical interventions include high-frequency percussive ventilation, perfluorohexane, inhaled anticoagulants, and nebulized epinephrine. The animal model, dose, clinical application, and pharmacology of these medications are summarized. Future directions and further needs for developing innovative therapies are discussed.

Co-administration of N-acetylcysteine and dexmedetomidine plays a synergistic effect on protection of LPS-induced acute lung injury via correcting Th1/Th2/Th17 cytokines imbalance

Recently both N-acetylcysteine (NAC) and Dexmedetomidine (DEX) have shown emerging roles in protection of acute lung injury (ALI). However, how their protective roles work and whether they can provide synergistic effects in ALI remain unknown. Here we explored it from the hot research viewpoint of Th1/Th2/Th17 cytokines balance. Lipopolysaccharide (LPS)-induced ALI was established and treated with NAC and/or DEX. Mice were divided into Sham group, ALI group, NAC group, DEX group and NAC+DEX group. Mice were sampled at 6, 12 and 24 hours after the model construction. Histopathology, wet to dry ratio and myeloperoxidase (MPO) activity were assessed in lung tissues. Protein concentration and cell count were assessed in bronchoalveolar lavage fluid (BALF). Th1/Th2/Th17 cytokines were assessed in plasma, BALF and lung homogenate. ALI-induced lung morphological damage, edema and aberrant MPO activity can be attenuated by NAC or DEX and mostly by NAC+DEX. NAC with DEX significantly reduced ALI-induced protein leakage and cell infiltration in BALF. Th1/Th2/Th17 cytokines imbalance aggravated with ALI progression. NAC, DEX and especially NAC+DEX can effectively correct these unbalanced cytokines. Galectin-9 and Tim-3 were transcriptionally up-regulated in ALI. Combination of NAC with DEX obtained a maximum effect on decreasing Galectin-9/Tim-3 expression. In summary, Th1/Th2/Th17 cytokines imbalance is newly found to participate in LPS-induced ALI. NAC or DEX administration can attenuate ALI by rebalancing Th1/Th2/Th17 cytokines. Their protective roles can be enhanced when co-administration, because DEX may relieve the Galectin-9/Tim-3 axis-mediated immune suppression.

Taurine enhances the protective effect of Dexmedetomidine on sepsis-induced acute lung injury via balancing the immunological system

Sepsis, an overwhelming systemic inflammatory disease, is the leading cause of acute lung injury (ALI). Despite plenty of researches have been done, effective drugs treating septic ALI are still eagerly needed in the clinic. Dexmedetomidine (Dex), a potent alpha-2 adrenoreceptor agonist, has been reported to possess antioxidant, anti-apoptosis and anti-inflammatory abilities. Taurine, a kind of intracellular free amino acid, has been used to treat various diseases. This study aimed to explore the combination effect of Dex and Taurine on septic ALI and the underlying mechanism in vivo. The establishment of septic ALI was set up in SD rats by cecal ligation and puncture (CLP) operation. Results indicated that Dex or Taurine could reduce septic ALI-induced cell apoptosis via decreasing caspase-3 activity. However, the combination of Dex or Taurine produced greater effect. Besides that, Dex combined with Taurine could better promote cell proliferation with remarkably elevated Ki67 expression. The combination of Dex and Taurine significantly suppressed the activation of NF-κB pathway via inhibiting P65 phosphorylation and P65 nuclear translocation, leading to the down-regulation of interleukin (IL)-6 and IL-1β. Moreover, co-administration of Dex and Taurine alleviated the imbalance of Th1/Th2 induced by septic ALI to a great extent. All in all, our study suggested the synergistic therapeutic effect of Dex and Taurine on septic ALI.

Animal models of smoke inhalation injury and related acute and chronic lung diseases

Smoke inhalation injury leads to various acute and chronic lung diseases and thus is the dominant cause of fire-related fatalities. In a search for an effective treatment and validation of therapies different classes of animal models have been developed, which include both small and large animals. These models have advanced our understanding of the mechanism of smoke inhalation injury, enabling a better understanding of pathogenesis and pathophysiology and development of new therapies. However, none of the animal models fully mirrors human lungs and their pathologies. All animal models have their limitations in replicating complex clinical conditions associated with smoke inhalation injury in humans. Therefore, for a correct interpretation of the results and to avoid bias, a precise understanding of similarities and differences of lungs between different animal species and humans is critical. We have reviewed and presented comprehensive comparison of different animal models and their clinical relevance. We presented an overview of methods utilized to induce smoke inhalation injuries, airway micro-/macrostructure, advantages and disadvantages of the most commonly used small and large animal models.

Mechanism of aquaporin 4 (AQP 4) up-regulation in rat cerebral edema under hypobaric hypoxia and the preventative effect of puerarin

AIM

We aim to investigate the mechanism of aquaporin 4 (AQP 4) up-regulation during high-altitude cerebral edema (HACE) in rats under hypobaric hypoxia and preventative effect of puerarin.

METHODS

Rats were exposed to a hypobaric chamber with or without the preventative treatment of puerarin or dexamethasone. Morriz water maze was used to evaluate the spatial memory injury. HE staining and W/D ratio were used to evaluate edema injury. Rat astrocytes and microglia were co-cultured under the condition of hypoxia with the administration of p38 inhibitor, NF-κB inhibitor or puerarin. Interleukin 6 (IL-6) and tumor necrosis factor α (TNF α) of cortex and culture supernatant were measured with ELISA. AQP4, phosphorylation of MAPKs, NF-κB pathway of cortex and astrocytes were measured by Western blot.

KEY FINDINGS

Weakened spatial memory and cerebral edema were observed after hypobaric hypoxia exposure. AQP4, phosphorylation of NF-κB and MAPK signal pathway of cortex increased after hypoxia exposure and decreased with preventative treatment of puerarin. Hypoxia increased TNF-α and IL-6 levels in cortex and microglia and puerarin could prevent the increase of them. AQP4 of astrocytes increased after co-cultured with microglia when both were exposed to hypoxia. AQP4 showed a decrease after administered with p38 inhibitor, NF-κB inhibitor or puerarin.

SIGNIFICANCE

Hypoxia triggers inflammatory response, during which AQP4 of astrocytes can be up regulated through the release of TNF-α and IL-6 from microglia. Puerarin can exert a preventative effect on the increase of AQP4 through inhibiting the release of TNF-α and phosphorylation of NF-κB, MAPK pathway.

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

OBJECTIVE

Hypobaric hypoxia, frequently encountered at high altitude, may lead to lung and cerebrum injury. Our study aimed to investigate whether puerarin could exert ameliorative effects on rats exposed to hypobaric hypoxia via regulation of aquaporin (AQP) and NF-κB signaling pathway in lung and cerebrum.

MATERIALS AND METHODS

40 Sprague Dawley rats were divided into four groups (normal control group, hypobaric hypoxia group, puerarin group and dexamethasone group). Wet/dry ratio, blood gas, pathological changes of lung and cerebrum and spatial memory were observed in each group. Inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were determined with ELISA and expression of AQP1, AQP4, NF-κB signaling pathway in lung and cerebrum with western blot RESULTS: Puerarin showed significant preventative effects on tissue injury and behavioral changes, as evidenced by histopathological findings and Morris water maze. In addition, levels of inflammatory cytokines in BALF decreased in the two preventative groups compared with those of hypobaric hypoxia group. AQP in lung and cerebrum increased under the condition of hypobaric hypoxia while was down regulated in both two preventative groups. NF-κB and IκB was also inhibited by puerarin.

CONCLUSION

Our study suggested that lung and cerebrum injury, increased inflammatory cytokines in BALF and increased AQP1, AQP4 and NF-κB signaling pathway occurred under the condition of hypobaric hypoxia. Moreover, puerarin could prevent lung and cerebrum injury of rats exposed to hypobaric hypoxia via down-regulation of inflammatory cytokines, AQP1 and AQP4 expression and NF-κB signaling pathway.

Sisymbrium Officinale (L.) Scop. and its Polyphenolic Fractions Inhibit the Mutagenicity of Tert-Butylhydroperoxide in Escherichia Coli WP2uvrAR Strain

One Sisymbrium officinale (L.) Scop. aqueous dry extract (SOE) and its polyphenolic fractions (Fb, Fc, Fd and Fe) were evaluated for their ability to inhibit the oxidative mutagenicity of tert-butylhydroperoxide in the Ames test. The possible involvement of desmutagenic and/or bioantimutagenic mechanisms was evaluated by applying a three-time based protocol (pre-treatment, co-treatment and post-treatment). Furthermore, some protective antioxidant mechanisms were investigated. The total polyphenol and flavonol amount was also determined, and the fingerprint was outlined by high-performance thin-layer chromatography and densitometry. SOE, Fb and Fe exhibited strong antimutagenicity against tert-butylhydroperoxide in all treatment protocols, this suggesting the involvement of both desmutagenic and bioantimutagenic mechanisms. These samples also showed antioxidant properties, including neutralization of the superoxide anion, lipid peroxidation inhibition and chelation and reduction of iron. Fb and Fe were rich in polyphenols and flavonols, so suggesting a possible role of these compounds in the antimutagenicity. Taking into account that oxidative stress is responsible for the damage of various environmental toxicants, particularly tobacco smoke, present results can support the traditional use of hedge mustard by smokers to restore the vocal cord function affected by the oxidative damage and suggest a possible application of SOE and its fractions as food supplements. Copyright © 2016 John Wiley & Sons, Ltd.