Chrysin attenuates carrageenan-induced pleurisy and lung injury via activation of SIRT1/NRF2 pathway in rats

CM1, a Chrysin Derivative, Protects from Endotoxin-Induced Lethal Shock by Regulating the Excessive Activation of Inflammatory Responses

Sepsis, a leading cause of death worldwide, is a harmful inflammatory condition that is primarily caused by an endotoxin released by Gram-negative bacteria. Effective targeted therapeutic strategies for sepsis are lacking. In this study, using an in vitro and in vivo mouse model, we demonstrated that CM1, a derivative of the natural polyphenol chrysin, exerts an anti-inflammatory effect by inducing the expression of the ubiquitin-editing protein TNFAIP3 and the NAD-dependent deacetylase sirtuin 1 (SIRT1). Interestingly, CM1 attenuated the Toll-like receptor 4 (TLR4)-induced production of inflammatory cytokines by inhibiting the extracellular-signal-regulated kinase (ERK)/MAPK and nuclear factor kappa B (NF-κB) signalling pathways. In addition, CM1 induced the expression of TNFAIP3 and SIRT1 on TLR4-stimulated primary macrophages; however, the anti-inflammatory effect of CM1 was abolished by the siRNA-mediated silencing of TNFAPI3 or by the genetic or pharmacologic inhibition of SIRT1. Importantly, intravenous administration of CM1 resulted in decreased susceptibility to endotoxin-induced sepsis, thereby attenuating the production of pro-inflammatory cytokines and neutrophil infiltration into the lung compared to control mice. Collectively, these findings demonstrate that CM1 has therapeutic potential for diverse inflammatory diseases, including sepsis.

Nrf2-mediated therapeutic effects of dietary flavones in different diseases

Oxidative stress (OS) is a pathological status that occurs when the body's balance between oxidants and antioxidant defense systems is broken, which can promote the development of many diseases. Nrf2, a redox-sensitive transcription encoded by NFE2L2, is the master regulator of phase II antioxidant enzymes and cytoprotective genes. In this context, Nrf2/ARE signaling can be a compelling target against OS-induced diseases. Recently, natural Nrf2/ARE regulators like dietary flavones have shown therapeutic potential in various acute and chronic diseases such as diabetes, neurodegenerative diseases, ischemia-reperfusion injury, and cancer. In this review, we aim to summarize nrf2-mediated protective effects of flavones in different conditions. Firstly, we retrospected the mechanisms of how flavones regulate the Nrf2/ARE pathway and introduced the mediator role Nrf2 plays in inflammation and apoptosis. Then we review the evidence that flavones modulated Nrf2/ARE pathway to prevent diseases in experimental models. Based on these literature, we found that flavones could regulate Nrf2 expression by mechanisms below: 1) dissociating the binding between Nrf2 and Keap1 via PKC-mediated Nrf2 phosphorylation and P62-mediated Keap1 autophagic degradation; 2) regulating Nrf2 nuclear translocation by various kinases like AMPK, MAPKs, Fyn; 3) decreasing Nrf2 ubiquitination and degradation via activating sirt1 and PI3K/AKT-mediated GSK3 inhibition; and 4) epigenetic alternation of Nrf2 such as demethylation at the promoter region and histone acetylation. In conclusion, flavones targeting Nrf2 can be promising therapeutic agents for various OS-related disorders. However, there is a lack of investigations on human subjects, and new drug delivery systems to improve flavones' treatment efficiency still need to be developed.

Inhibitory effect of hydroalcoholic extract of Cunila spicata Benth. on phlogistic agents-induced cellular migration in the airways of mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cunila spicata Benth. Is a creeping and aromatic plant that has an ethnopharmacological indication in the southern region of Brazil, in the Araucaria Forest biome. It's used as an alternative therapy for respiratory diseases for men and animals since the "tropeirista" movement in colonial Brazil.

AIM OF THE STUDY

Investigate the influence of oral administration of hydroalcoholic extract of C. spicata (HECS) on cellular inflammatory processes in the airways of mice.

MATERIAL AND METHODS

The HECS was obtained by the ultrasound-assisted technique. Phytochemical analysis of the volatile compounds was performed using gas-chromatography with mass spectrometry. To investigate the biological activity of HECS, the animals were pre-treated with HECS orally 1 h before and the bronchoalveolar lavage (BAL) model was used, in which the animals were subjected to inhalation of different pro-inflammatory agents such as carrageenan (CAR), histamine (HIST), capsaicin (CAP), bradykinin (BK), and 48/80 compound (C48/80). After sacrifice, BAL sample was collected from the bronchi and was analyzed for total and differential white blood cell counts, compared with control groups.

RESULTS

Fourteen volatile phytocompounds were identified in the HECS, the main ones being 2-bornanone, menthofuran and camphene. Among the HECS treated animals, all showed significant maximal inhibition (MI) when challenged with pro-inflammatory agents by nebulization. In the group of animals that received CAR, the MI was 72.77 ± 3.88%, compared to the negative control (NC). There was a predominance of lymphocytes (59.18 ± 4.07%). For the HIST group, MI was 64.03 ± 4.33%, in relation to the NC, with predominance in macrophages number (76.53 ± 2.78%). In the CAP group, the MI obtained was 38.90 ± 11.31%, with greater macrophage migration occurring (80.98 ± 3.44%) in the higher dose. For animals subjected to BK inhalation, the MI was 48.63 ± 3.95% with macrophages predominance (64.33 ± 10.04%). In the group that received C48/80 inhalation, the MI was 40.25 ± 5.30% (100 mg kg^-1), with higher occurrence of macrophages (72.97 ± 4.23%).

CONCLUSION

Our results suggest that HECS had a non-specific inhibitory effect on cellular migration induced by different pro-inflammatory agents, reducing inflammation in airways of mice. These effects coincide and support its ethnopharmacological use as an alternative medicine for respiratory diseases in regions where the plant is prevalent.

Synergic Effect of Honey with Other Natural Agents in Developing Efficient Wound Dressings

Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey's biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health. The review also presents some mechanisms of action and the medical applications of honey, such as wound healing dressings, skin grafts, honey-based nanofibers, and cochlear implants, as the most promising wound healing tools. This extensive review has been written to highlight honey's applications in medicine; its composition with the most important bioactive compounds also illustrates its synergistic effect with other natural products having remarkable therapeutic properties in wound healing.

Role of Nuclear Factor Erythroid 2 (Nrf2) in the Recovery of Long COVID-19 Using Natural Antioxidants: A Systematic Review

Coronavirus disease 2019 (COVID-19) is an infectious disease with approximately 517 million confirmed cases, with the average number of cases revealing that patients recover immediately without hospitalization. However, several other cases found that patients still experience various symptoms after 3–12 weeks, which is known as a long COVID syndrome. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can activate nuclear factor kappa beta (NF-κβ) and unbind the nuclear factor erythroid 2-related factor 2 (Nrf2) with Kelch-like ECH-associated protein 1 (Keap1), causing inhibition of Nrf2, which has an important role in antioxidant response and redox homeostasis. Disrupting the Keap1–Nrf2 pathway enhances Nrf2 activity, and has been identified as a vital approach for the prevention of oxidative stress and inflammation. Hence, natural antioxidants from various sources have been identified as a promising strategy to prevent oxidative stress, which plays a role in reducing the long COVID-19 symptoms. Oxygen-rich natural antioxidant compounds provide an effective Nrf2 activation effect that interact with the conserved amino acid residues in the Keap1-binding pocket, such as Ser602, Ser363, Ser508, and Ser555. In this review, the benefits of various natural antioxidant compounds that can modulate the Nrf2 signaling pathway, which is critical in reducing and curing long COVID-19, are highlighted and discussed.

Leonurine inhibits the TXNIP/NLRP3 and NF-κB pathways via Nrf2 activation to alleviate carrageenan-induced pleurisy in mice

Oxidative stress and inflammation play important roles in pleurisy. Leonurine (Leo) has been confirmed to exert antioxidative and antiinflammatory effects in many preclinical experiments, but these effects have not been studied in pleurisy. The aim of this study was to explore the therapeutic effect and mechanism of Leo in a carrageenan (CAR)-induced pleurisy model. In this study, we found that the increase of reactive oxygen species (ROS), myeloperoxidase (MPO), and malondialdehyde (MDA) and decrease of glutathione (GSH) induced by CAR could be reversed by the treatment of Leo. Leo effectively reduced the levels of proinflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the percentages of mature macrophages and increased the levels of antiinflammatory cytokines (IL-10). Furthermore, Western blotting revealed that Leo significantly activated the Nrf2 pathway to restrain the thioredoxin-interacting protein/NOD-like receptor protein 3 (TXNIP/NLRP3) and nuclear factor kappa-B (NF-κB) pathways. However, the protective effect of Leo was significantly weakened in Nrf2-deficient mice. These results indicate that Leo confers potent protection against CAR-induced pleurisy by inhibiting the TXNIP/NLRP3 and NF-κB pathways dependent on Nrf2, which may serve as a promising agent for attenuating pleurisy.

The Potential Use of Propolis as a Primary or an Adjunctive Therapy in Respiratory Tract-Related Diseases and Disorders: A Systematic Scoping Review

Propolis is a resinous beehive product that is collected by the bees from plant resin and exudates, to protect and maintain hive homeostasis. Propolis has been used by humans therapeutically to treat many ailments including respiratory tract-related diseases and disorders. The aim of the present systematic scoping review is to evaluate the experimental evidence to support the use of propolis as a primary or an adjunctive therapy in respiratory tract-related diseases and disorders. After applying the exclusion criteria, 158 research publications were retrieved and identified from Scopus, Web of Science, Pubmed, and Google Scholar. The key themes of the included studies were pathogenic infection-related diseases and disorders, inflammation-related disorders, lung cancers, and adverse effects. Furthermore, the potential molecular and biochemical mechanisms of action of propolis in alleviating respiratory tract-related diseases and disorders are discussed. In conclusion, the therapeutic benefits of propolis have been demonstrated by various in vitro studies, in silico studies, animal models, and human clinical trials. Based on the weight and robustness of the available experimental and clinical evidence, propolis is effective, either as a primary or an adjunctive therapy, in treating respiratory tract-related diseases.

Danshensu attenuates cisplatin-induced nephrotoxicity through activation of Nrf2 pathway and inhibition of NF-κB

The clinical application of cisplatin was mainly limited by severe nephrotoxicity. Danshensu was the main pharmacological active diterpenoids which extracted from the roots of Salvia milthiorriza Bunge. This study is aimed to investigate the protective effects and potential mechanisms of Danshensu against cisplatin-induced nephrotoxicity. After fasting for 12 h, all mice groups except the control group were administered a single intraperitoneal injection of 25 mg/kg cisplatin. 1 h later, cisplatin (25 mg/kg) + Danshensu (15 mg/kg, 30 mg/kg, 60 mg/kg) groups were treated with corresponding doses of Danshensu once a day for 7 consecutive days. Blood urea nitrogen (BUN), creatinine, reactive oxygen species (ROS), superoxide dismutase (SOD), Glutathione peroxidase (GPx), Catalase (CAT) and malondialdehyde (MDA) were assayed in this study. The expression of inflammatory cytokines TNF-α, IL-6 and IL-1β were examined by ELISA. The results showed that Danshensu could improve kidney damage, attenuate serum BUN, creatinine, cytokines and oxidative stress markers. Further studies showed that Danshensu can induce Nrf2/HO-1 activation and inhibition of NF-κB pathway. In conclusion, Danshensu exerts the protective effects on cisplatin-induced nephrotoxicity, which may be related to the activation of Nrf2/HO-1 and inhibition of NF-ĸB pathway.

Flavonoids as potential phytotherapeutics to combat cytokine storm in SARS-CoV-2

Emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, COVID-19, has become the global panic since December 2019, which urges the global healthcare professionals to identify novel therapeutics to counteract this pandemic. So far, there is no approved treatment available to control this public health issue; however, a few antiviral agents and repurposed drugs support the patients under medical supervision by compromising their adverse effects, especially in emergency conditions. Only a few vaccines have been approved to date. In this context, several plant natural products-based research studies are evidenced to play a crucial role in immunomodulation that can prevent the chances of infection as well as combat the cytokine release storm (CRS) generated during COVID-19 infection. In this present review, we have focused on flavonoids, especially epicatechin, epigallocatechin gallate, hesperidin, naringenin, quercetin, rutin, luteolin, baicalin, diosmin, ge nistein, biochanin A, and silymarin, which can counteract the virus-mediated elevated levels of inflammatory cytokines leading to multiple organ failure. In addition, a comprehensive discussion on available in silico, in vitro, and in vivo findings with critical analysis has also been evaluated, which might pave the way for further development of phytotherapeutics to identify the potential lead candidatetoward effective and safe management of the SARS-CoV-2 disease.

Involvement of SIRT1 in amelioration of schistosomiasis-induced hepatic fibrosis by genistein

Previous study revealed that genistein alleviate the extent of hepatic fibrosis in schistosomiasis-infected mice, however, the potential mechanism is still incomplete. Present study was, therefore, carried out to investigate the underlying mechanism of ameliorating schistosomiasis-induced hepatic fibrosis by genistein. α-smooth muscle actin (α-SMA) expression, as a critical fibrotic marker, was markedly upregulated in Schistosoma japonicum (S. japonicum) egg-induced liver fibrosis, and gradually inhibited by genistein administration in infected mice. Contrary to the changes of α-SMA expression, hepatic SIRT1 expression and activity was greatly inhibited in mice upon S. japonicum infection, and the repression was reversed in liver tissues after receiving 25 mg/kg genistein. 50 mg/kg genistein treatment gave rise to the higher SIRT1 expression and activity than that of the control group. In hepatic stellate cells (HSCs), genistein (5, 10, 20 μM) treatment resulted in the increases of SIRT1 expression and activity in concentration-dependent manner. Moreover, to mimic the fibrogenesis in vivo, macrophage was treated with soluble egg antigen (SEA) to obtain macrophage-conditioned medium (MφCM), which was used to stimulate HSCs. Intriguingly, SIRT1 overexpression decreased fibrosis associated gene expression in HSCs exposed to MφCM or not. Additionally, MφCM gave rise to high levels of α-SMA and p-Smad3 and the increments were reversed upon genistein treatment in HSCs. Furthermore, EX527, SIRT1 specific inhibitor, abrogated the inhibitory effects of genistein on HSCs activation. Together, the results support the notion that the strong elevation of SIRT1 expression and activity may represent a potential mechanism of protection against schistosomiasis-induced hepatic fibrosis by genistein.

Targeting RFWD2 as an Effective Strategy to Inhibit Cellular Proliferation and Overcome Drug Resistance to Proteasome Inhibitor in Multiple Myeloma

The potential to overcome resistance to proteasome inhibitors is greatly related with ubiquitin-proteasome system during multiple myeloma (MM) treatment process. The constitutive photomorphogenic 1 (RFWD2), referred to an E3 ubiquitin ligase, has been identified as an oncogene in multiple cancers, yet important questions on the role of RFWD2 in MM biology and treatment remain unclear. Here we demonstrated that MM patients with elevated RFWD2 expression achieved adverse outcome and drug resistance by analyzing gene expression profiling. Moreover, we proved that RFWD2 participated in the process of cell cycle, cell growth and death in MM by mass spectrometry analysis. In vitro study indicated that inducible knockdown of RFWD2 hindered cellular growth and triggered apoptosis in MM cells. Mechanism study revealed that RFWD2 controlled MM cellular proliferation via regulating the degradation of P27 rather than P53. Further exploration unveiled that RFWD2 meditated P27 ubiquitination via interacting with RCHY1, which served as an E3 ubiquitin ligase of P27. Finally, in vivo study illustrated that blocking RFWD2 in BTZ-resistant MM cells overcame the drug resistance in a myeloma xenograft mouse model. Taken together, these findings provide compelling evidence for prompting that targeting RFWD2 may be an effective strategy to inhibit cellular proliferation and overcome drug resistance to proteasome inhibitor in MM.

Possible Potential Effects of Honey and Its Main Components Against Covid-19 Infection

Coronavirus disease 2019 (COVID-19) is a viral pneumonia that is spreading rapidly worldwide. The main feature of this disease is a severe acute respiratory syndrome and caused by coronavirus 2 (SARS-CoV-2). There are several unknowns about the pathogenesis and therapeutically treatment of COVID-19 infection. In addition, available treatment protocols have not been effective in managing COVID-19 infection. It is proposed that natural anti-oxidants such as lemon, green tea, saffron, curcuma longa, etc. with high flavonoids like safranal, crocin, crocetin, catechins, resveratrol, calebin A, curcumin have therapeutic potential against viral infections. In this context, honey and its main components are being investigated as an option for patients with COVID-19. The present study may indicate that honey and its main components inhibit the entry of the virus into the host cell and its replication as well as modulate the inflammatory cascade. This review provides basic information for the possible potential effects of honey and its main components for fighting with SARS-CoV-2.

CKLF1/CCR5 axis is involved in neutrophils migration of rats with transient cerebral ischemia

BACKGROUND

Chemokine-like factor 1 (CKLF1) is a chemokine increased significantly in ischemic brain poststroke. It shows chemotaxis effects on various immune cells, but the mechanisms of CKLF1 migrating neutrophils are poorly understood. Recent studies have provided evidence that CC chemokine receptor 5 (CCR5), a receptor of CKLF1, is involved in ischemic stroke.

PURPOSES

To investigate the effects of HIF-1α guided AAV in ischemic brain, investigating the outcome of stroke, and examining the involvement of CKLF1/CCR5 axis in recruitment of neutrophils.

RESULTS

HIF-1α guided AAV knocked down CKLF1 in ischemic area and alleviated brain damage of rats. CKLF1 migrated neutrophils through CCR5, worsening inflammatory responses. Akt/GSK-3β pathway may involve in CKLF1/CCR5 axis guided neutrophils chemotaxis.

CONCLUSIONS

CKLF1/CCR5 axis is involved in neutrophils migration of rats with transient cerebral ischemia. CKLF1/CCR5 axis may be a useful target for stroke therapy.

Genistein protects against acetaminophen-induced liver toxicity through augmentation of SIRT1 with induction of Nrf2 signalling

Previous studies suggest that genistein protects liver from acetaminophen (APAP)-induced injury, however, the detailed mechanism of the process is still incompletely. Therefore, present study was to investigate the potential mechanism of the genistein mediated protection against APAP-induced hepatotoxicity. As shown, supplementation with 150 mg/kg genistein greatly alleviated the increase in serum alanine aminotransferase (ALT) activity, aspartate aminotransferase (AST) activity, hepatic malondialdehyde (MDA) contents, and reversed the decrease in hepatic GSH levels in response to overdose APAP. At the same time, hepatic SIRT1 protein and activity were markedly upregulated in mouse receiving genistein. However, the amelioration was almost abolished by the knockdown of hepatic SIRT1 expression using lentivirus carrying specific shRNA targeting SIRT1. These results were further validated by histopathology examination. Moreover, depletion of hepatic SIRT1 prevented the accumulation of Nrf2 in nucleus and the upregulation of the antioxidant gene expression in the presence of genistein and/or APAP. Concomitantly, the induced mRNA expression of UDP-glucuronosyltransferases (UGTs) by genistein was largely dependent on the SIRT1 expression and activity. Together, our results support the notion that the strong elevation of SIRT1 expression and activity may represent a potential mechanism of protection against APAP-induced liver injury by genistein.

Isoliquiritigenin exerts antioxidative and anti-inflammatory effects via activating the KEAP-1/Nrf2 pathway and inhibiting the NF-κB and NLRP3 pathways in carrageenan-induced pleurisy

Pleurisy refers to a pleural disease caused by pathogenic factors that stimulate the pleura associated with pleural inflammation and oxidative stress. Isoliquiritigenin (ISL), a flavonoid from the liquorice compound, possesses antioxidative and anti-inflammatory properties. In the current study, we investigated the protective effects of ISL on carrageenan-induced pleurisy and lung injury in mice. The mice were intraperitoneally injected with ISL (30 mg kg^-1) twice (each time interval of 12 h), followed by exposure to Car 1 h after the second dose of ISL. Our results indicated that ISL treatment significantly alleviated carrageenan-induced histopathological damage and increased levels of inflammatory cell exudation, protein leakage, and pro-inflammatory mediators. Meanwhile, ISL inhibited reactive oxygen species (ROS) generation, MDA and MPO formation, and SOD and GSH depletion induced by carrageenan. In addition, it decreased the GSSG level and GSSG-to-GSH ratio. In terms of the mechanism, ISL inhibited NOX2 and NOX4 levels, caused the dissociation of KEAP-1 and Nrf2, and activated the downstream genes HO-1, NQO1, GCLC and GCLM, thus decreasing oxidative stress. In addition, ISL exerts protective effects against inflammation by suppressing the NOD-like receptor protein 3 (NLRP3)/NF-κB pathway and the high levels of iNOS and COX-2. In summary, our results reinforce the hypothesis that ISL exerts protective effects on carrageenan-induced pleurisy and lung injury in a manner that can be attributed to Nrf2-mediated antioxidative activities and NLRP3/NF-κB-mediated anti-inflammatory activities.

Treating severe wounds in pediatrics with medical grade honey: A case series

Medical grade honey (MGH) has antimicrobial and pro-healing properties. We here demonstrate that MGH is an easily applicable, safe, and cost-effective approach for severe wounds. The use of MGH should more often be considered to treat all kinds of pediatric wounds.