Molecular mechanisms underlying the in vitro anti-inflammatory effects of a flavonoid-rich ethanol extract from chinese propolis (poplar type)

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

Virtual screening and computational simulation analysis of antimicrobial photodynamic therapy using propolis-benzofuran A to control of Monkeypox

BACKGROUND

Monkeypox is a viral zoonotic disease and there are no available treatments that specifically target the monkeypox virus. Antimicrobial photodynamic therapy (aPDT) is a non-invasive approach that has been introduced as a targeted adjuvant treatment against various microbial infections. In this study, we used a computational strategy to investigate the potential of aPDT using propolis-benzofuran A against the Monkeypox virus.

METHODS

In this in silico study, the evaluation of drug-likeness, molecular properties, and bioactivity of propolis-benzofuran A was carried out using SwissADME. Pro-Tox II and OSIRIS servers were used to identify the organ toxicities and toxicological endpoints of propolis-benzofuran A. Molecular docking approach was employed to screen the potential binding modes of propolis-benzofuran A ligand with the Monkeypox virus A48R protein (PDB ID: 2V54).

RESULTS

The results of the computational investigation revealed that propolis-benzofuran A obeyed all the criteria of Lipinski's rule of five and exhibited drug-likeness. The photosensitizing agent tested was categorized as toxicity class-5 and was found to be non-hepatotoxic, non-carcinogenic, non-mutagenic, and non-cytotoxic. The docking studies employing a predicted three-dimensional model of Monkeypox virus A48R protein with propolis-benzofuran A ligand exhibited good binding affinity (-7.84 kcal/mol).

DISCUSSION

The computational simulation revealed that propolis-benzofuran A had a strong binding affinity with the Monkeypox virus A48R protein. Hence, aPDT based on this natural photosensitizer can be proposed as an adjuvant treatment against the Monkeypox virus.

Natural Immunomodulators Treat the Cytokine Storm in SARS-CoV-2

Recently, the world has been dealing with a destructive global pandemic Coronavirus disease 2019 (COVID-19) infection, since 2020; there were millions of infections and hundreds of thousands of deaths worldwide. With sequencing generations of the virus, around 60% are expected to become infected during the pandemic. Unfortunately, no drug or vaccine has been approved because no real evidence from clinical trials in treatment was reached. According to current thinking, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mortality is caused by a cytokine storm syndrome in patients with hyper-inflammatory conditions, resulting in acute respiratory distress and finally death. In this review, we discuss the various types of natural immune-modulatory agents and their role in the management of SARS-CoV-2, and cytokine storm syndrome. For example, Polyphenols as natural products can block the binding of SARS-CoV-2 spike protein to host cell receptor ACE2, stop viral entry into the host cell and block viral RNA replication. Also, saikosaponins (A, B2, C, and D), triterpene glycosides, which are isolated from medicinal plants exert antiviral action against HCoV-22E9, and Houttuynia cordata water extract has antiviral effects on SARS-CoV. Moreover, eucalyptus oil has promising potential for COVID-19 prevention and treatment. There is an urgent need for research to improve the function of the human immune system all over the world. As a result, actions for better understanding and improving the human immune system are critical steps toward mitigating risks and negative outcomes. These approaches will be strongly recommended for future emerging viruses and pathogens.

Antioxidant, Anti-inflammatory, and Immunomodulatory Roles of Nonvitamin Antioxidants in Anti-SARS-CoV-2 Therapy

Viral pathologies encompass activation of pro-oxidative pathways and inflammatory burst. Alleviating overproduction of reactive oxygen species and cytokine storm in COVID-19 is essential to counteract the immunogenic damage in endothelium and alveolar membranes. Antioxidants alleviate oxidative stress, cytokine storm, hyperinflammation, and diminish the risk of organ failure. Direct antiviral roles imply: impact on viral spike protein, interference with the ACE2 receptor, inhibition of dipeptidyl peptidase 4, transmembrane protease serine 2 or furin, and impact on of helicase, papain-like protease, 3-chyomotrypsin like protease, and RNA-dependent RNA polymerase. Prooxidative environment favors conformational changes in the receptor binding domain, promoting the affinity of the spike protein for the host receptor. Viral pathologies imply a vicious cycle, oxidative stress promoting inflammatory responses, and vice versa. The same was noticed with respect to the relationship antioxidant impairment-viral replication. Timing, dosage, pro-oxidative activities, mutual influences, and interference with other antioxidants should be carefully regarded. Deficiency is linked to illness severity.

Molecular and Cellular Mechanisms of Propolis and Its Polyphenolic Compounds against Cancer

In recent years, interest in natural products such as alternative sources of pharmaceuticals for numerous chronic diseases, including tumors, has been renewed. Propolis, a natural product collected by honeybees, and polyphenolic/flavonoid propolis-related components modulate all steps of the cancer progression process. Anticancer activity of propolis and its compounds relies on various mechanisms: cell-cycle arrest and attenuation of cancer cells proliferation, reduction in the number of cancer stem cells, induction of apoptosis, modulation of oncogene signaling pathways, inhibition of matrix metalloproteinases, prevention of metastasis, anti-angiogenesis, anti-inflammatory effects accompanied by the modulation of the tumor microenvironment (by modifying macrophage activation and polarization), epigenetic regulation, antiviral and bactericidal activities, modulation of gut microbiota, and attenuation of chemotherapy-induced deleterious side effects. Ingredients from propolis also "sensitize" cancer cells to chemotherapeutic agents, likely by blocking the activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). In this review, we summarize the current knowledge related to the the effects of flavonoids and other polyphenolic compounds from propolis on tumor growth and metastasizing ability, and discuss possible molecular and cellular mechanisms involved in the modulation of inflammatory pathways and cellular processes that affect survival, proliferation, invasion, angiogenesis, and metastasis of the tumor.

Propolis: An update on its chemistry and pharmacological applications

Propolis, a resinous substance produced by honeybees from various plant sources, has been used for thousands of years in traditional medicine for several purposes all over the world. The precise composition of propolis varies according to plant source, seasons harvesting, geography, type of bee flora, climate changes, and honeybee species at the site of collection. This apiary product has broad clinical applications such as antioxidant, anti-inflammatory, antimicrobial, anticancer, analgesic, antidepressant, and anxiolytic as well asimmunomodulatory effects. It is also well known from traditional uses in treating purulent disorders, improving the wound healing, and alleviating many of the related discomforts. Even if its use was already widespread since ancient times, after the First and Second World War, it has grown even more as well as the studies to identify its chemical and pharmacological features, allowing to discriminate the qualities of propolis in terms of the chemical profile and relative biological activity based on the geographic place of origin. Recently, several in vitro and in vivo studies have been carried out and new insights into the pharmaceutical prospects of this bee product in the management of different disorders, have been highlighted. Specifically, the available literature confirms the efficacy of propolis and its bioactive compounds in the reduction of cancer progression, inhibition of bacterial and viral infections as well as mitigation of parasitic-related symptoms, paving the way to the use of propolis as an alternative approach to improve the human health. However, a more conscious use of propolis in terms of standardized extracts as well as new clinical studies are needed to substantiate these health claims.

Gut microbiota in women with gestational diabetes mellitus has potential impact on metabolism in pregnant mice and their offspring

Studies have shown that gestational diabetes mellitus (GDM) is closely related to abnormalities in the gut microbiota, and the offspring of these women have an increased risk of diabetes. There is no direct evidence of whether bacteria in women with GDM colonize the intestinal tract of offspring and cause hyperglycemia. In this fecal microbiota transplantation (FMT), pregnant mouse model study, two groups of germ-free (GF) mice after FMT showed different colonization patterns of gut microbiota and phenotype. Compared with the control group (healthy-FMT), we found in the GDM-FMT group as a lower relative abundance of Akkermansia and Faecalibacterium; a lower content of short-chain fatty acids and naringenin in feces; an elevated blood glucose; an inflammatory factor expression (TNF-α, CXCL-15, and IL-6), and a hepatic fat deposition. In addition, the influence of the gut microbiota continued in offspring. The gut microbiota of the offspring of GDM-FMT mice was still different from that of the control group as a lower relative abundance of Akkermansia and Parvibacter; and a higher relative abundance of bacteria such as Oscillibacter, Romboutsia, and Harryflintia. In addition, the offspring of GDM-FMT mice had higher body weight and blood glucose levels than the control offspring.

Potential Effects of Romanian Propolis Extracts against Pathogen Strains

The impact of globalization on beekeeping brings new economic, scientific, ecological and social dimensions to this field The present study aimed to evaluate the chemical compositions of eight propolis extracts from Romania, and their antioxidant action and antimicrobial activity against seven species of bacteria, including pathogenic ones: Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Listeria monocytogenes and Salmonella enterica serovar Typhimurium. The phenolic compounds, flavonoids and antioxidant activity of propolis extracts were quantified; the presence of flavones and aromatic acids was determined. Quercetin and rutin were identified by HPLC analysis and characterized using molecular descriptors. All propolis samples exhibited antibacterial effects, especially against P. aeruginosa and L. monocytogenes. A two-way analysis of variance was used to evaluate correlations among the diameters of the inhibition zones, the bacteria used and propolis extracts used. Statistical analysis demonstrated that the diameter of the inhibition zone was influenced by the strain type, but no association between the propolis origin and the microbial activity was found.

COVID-19 pandemic: impacts on bees, beekeeping, and potential role of bee products as antiviral agents and immune enhancers

COVID-19 pandemic has passed to the front all the contradictions of the beekeeping sector: the valuable role of bee products as immune enhancers and antiviral agents and the impact that unsustainability of human activities has on bees' health and survival. The COVID-19 emergency led several countries to adopt severe restriction measures to contrast the infection. The lowering of industrial and commercial activities, transports, and the general lockdown had immediate consequences on the air quality, significantly improving environmental conditions. This had a positive impact on honeybees' life's quality. On the other hand, the bee and beehive transportation limitations threaten to hit food production by affecting the pollinator service, and this is particularly true in large, food-exporting countries like the USA and China where due to the few numbers of local bees, beekeepers import them by other countries and convey by truck hives for thousands of kilometers to pollinate crops. Furthermore, honeybee products, focusing on their natural pharmacological properties, can play an essential role as a potential natural contrast to the virus by enhancing the immunity defenses of both humans and animals, and their demand by consumers is expected to increase. Several researchers in the last months focused their attention on bee products to evaluate their effect in the cure of COVID-19 patients to ameliorate the symptoms or to contrast the coronavirus directly. This review reports these preliminary results.

Polyphenols as Antioxidants for Extending Food Shelf-Life and in the Prevention of Health Diseases: Encapsulation and Interfacial Phenomena

Toxicity caused by the exposure to human-made chemicals and environmental conditions has become a major health concern because they may significantly increase the formation of reactive oxygen species (ROS), negatively affecting the endogenous antioxidant defense. Living systems have evolved complex antioxidant mechanisms to protect cells from oxidative conditions. Although oxidative stress contributes to various pathologies, the intake of molecules such as polyphenols, obtained from natural sources, may limit their effects because of their antioxidant and antimicrobial properties against lipid peroxidation and against a broad range of foodborne pathogens. Ingestion of polyphenol-rich foods, such as fruits and vegetables, help to reduce the harmful effects of ROS, but the use of supramolecular and nanomaterials as delivery systems has emerged as an efficient method to improve their pharmacological and therapeutic effects. Suitable exogenous polyphenolic antioxidants should be readily absorbed and delivered to sites where pathological oxidative damage may take place, for instance, intracellular locations. Many potential antioxidants have a poor bioavailability, but they can be encapsulated to improve their ideal solubility and permeability profile. Development of effective antioxidant strategies requires the creation of new nanoscale drug delivery systems to significantly reduce oxidative stress. In this review we provide an overview of the oxidative stress process, highlight some properties of ROS, and discuss the role of natural polyphenols as bioactives in controlling the overproduction of ROS and bacterial and fungal growth, paying special attention to their encapsulation in suitable delivery systems and to their location in colloidal systems where interfaces play a crucial role.

Nonwoven Releasing Propolis as a Potential New Wound Healing Method-A Review

Wound healing poses a serious therapeutic problem. Methods which accelerate tissue regeneration and minimize or eliminate complications are constantly being sought. This paper is aimed at evaluation of the potential use of biodegradable polymer nonwovens releasing propolis as wound healing dressings, based on the literature data. Propolis is honeybee product with antioxidant, antibacterial, antifungal, anticancer, anti-inflammatory, analgesic, and regenerative properties. Controlled release of this substance throughout the healing should promote healing process, reduce the risk of wound infection, and improve aesthetic effect. The use of biodegradable aliphatic polyesters and polyester carbonates as a propolis carrier eliminates the problem of local drug administration and dressing changes. Well-known degradation processes and kinetics of the active substance release allows the selection of the material composition appropriate to the therapy. The electrospinning method allows the production of nonwovens that protect the wound against mechanical damage. Moreover, this processing technique enables adjusting product properties by modifying the production parameters. It can be concluded that biodegradable polymer dressings, releasing a propolis, may find potential application in the treatment of complicated wounds, as they may increase the effectiveness of treatment, as well as improve the patient’s life quality.

Antiviral, Antibacterial, Antifungal, and Antiparasitic Properties of Propolis: A Review

Propolis is a complex phytocompound made from resinous and balsamic material harvested by bees from flowers, branches, pollen, and tree exudates. Humans have used propolis therapeutically for centuries. The aim of this article is to provide comprehensive review of the antiviral, antibacterial, antifungal, and antiparasitic properties of propolis. The mechanisms of action of propolis are discussed. There are two distinct impacts with regards to antimicrobial and anti-parasitic properties of propolis, on the pathogens and on the host. With regards to the pathogens, propolis acts by disrupting the ability of the pathogens to invade the host cells by forming a physical barrier and inhibiting enzymes and proteins needed for invasion into the host cells. Propolis also inhibits the replication process of the pathogens. Moreover, propolis inhibits the metabolic processes of the pathogens by disrupting cellular organelles and components responsible for energy production. With regard to the host, propolis functions as an immunomodulator. It upregulates the innate immunity and modulates the inflammatory signaling pathways. Propolis also helps maintain the host's cellular antioxidant status. More importantly, a small number of human clinical trials have demonstrated the efficacy and the safety of propolis as an adjuvant therapy for pathogenic infections.

Chinese Propolis Suppressed Pancreatic Cancer Panc-1 Cells Proliferation and Migration via Hippo-YAP Pathway

Pancreatic cancer is one of the most malignant cancers with high mortality. Therefore, it is of great urgency to develop new agents that could improve the prognosis of Pancreatic cancer patients. Chinese propolis (CP), a flavonoid-rich beehive product, has been reported to have an anticancer effect. In this study, we applied CP to the human Pancreatic cancer cell line Panc-1 to verify its impact on tumor development. CP induced apoptosis in Panc-1 cells from 12.5 µg/mL in a time- and dose-dependent manner with an IC₅₀ value of approximately 50 µg/mL. Apoptosis rate induced by CP was examined by Annexing FITC/PI assay. We found that 48 h treatment with 50 µg/mL CP resulted in 34.25 ± 3.81% apoptotic cells, as compared to 9.13 ± 1.76% in the control group. We further discovered that the Panc-1 cells tended to be arrested at G2/M phase after CP treatment, which is considered to contribute to the anti-proliferation effect of CP. Furthermore, our results demonstrated that CP suppressed Panc-1 cell migration by regulating epithelial-mesenchymal transition (EMT). Interestingly, the Hippo pathway was activated in Panc-1 cells after CP treatment, serving as a mechanism for the anti-pancreatic cancer effect of CP. These findings provide a possibility of beehive products as an alternative treatment for pancreatic cancer.

Immunomodulatory Activity of Electrospun Polyhydroxyalkanoate Fiber Scaffolds Incorporating Olive Leaf Extract

Olive tree is a well-known source of polyphenols. We prepared an olive leaf extract (OLE) and characterized it via high performance liquid chromatography (HPLC) analysis. OLE was blended with different polyhydroxyalkanoates (PHAs), namely, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) and polyhydroxybutyrate/poly(hydroxyoctanoate-co-hydroxydecanoate) (PHB/PHOHD), to produce fiber meshes via electrospinning: OLE/PHBV and OLE/ (PHB/PHOHD), respectively. An 80–90% (w/w%) release of the main polyphenols from the OLE/PHA fibers occurred in 24 h, with a burst release in the first 30 min. OLE and the produced fiber meshes were assayed using human dermal keratinocytes (HaCaT cells) to evaluate the expression of a panel of cytokines involved in the inflammatory process and innate immune response, such as the antimicrobial peptide human beta defensin 2 (HBD-2). Fibers containing OLE were able to decrease the expression of the pro-inflammatory cytokines at 6 h up to 24 h. All the PHA fibers allowed an early downregulation of the pro-inflammatory cytokines in 6 h, which is suggestive of a strong anti-inflammatory activity exerted by PHA fibers. Differently from pure OLE, PHB/PHOHD fibers (both with and without OLE) upregulated the expression of HBD-2. Our results showed that PHA fiber meshes are suitable in decreasing pro-inflammatory cytokines and the incorporation of OLE may enable indirect antibacterial properties, which is essential in wound healing and tissue regeneration.

Medicinal plants and bioactive natural products as inhibitors of NLRP3 inflammasome

The NLR family, pyrin domain-containing 3 (NLRP3) inflammasome is a multiprotein complex that induces caspase-1 activation and the downstream substrates involved with the processing and secretion of the pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18 and tumor necrosis factor-α (TNF- α). The NLRP3 inflammasome is activated by a wide range of danger signals that derive from metabolic dysregulation. Activation of this complex often involves the adaptor ASC and upstream sensors including NLRP1, NLRP3, NLRC4, AIM2, and pyrin, which are activated by different stimuli including infectious agents and changes in cell homeostasis. It has been shown that nutraceuticals and medicinal plants have antiinflammatory properties and could be used as complementary therapy in the treatment of several chronic diseases that are related to inflammation, for example, cardiovascular diseases and diabetes mellitus. Herb-based medicine has demonstrated protective effects against NLRP3 inflammasome activation. Therefore, this review focuses on the effects of nutraceuticals and bioactive compounds derived from medicinal plants on NLRP3 inflammasome activation and the possible mechanisms of action of these natural products. Thus, herb-based, natural products/compounds can be considered novel, practical, and accessible agents in chronic inflammatory diseases by inhibiting NLRP3 inflammasome activation.

Propolis in Metabolic Syndrome and Its Associated Chronic Diseases: A Narrative Review

Propolis is a resinous product collected by bees from plants to protect and maintain the homeostasis of their hives. Propolis has been used therapeutically by humans for centuries. This review article attempts to analyze the potential use of propolis in metabolic syndrome (MetS) and its associated chronic diseases. MetS and its chronic diseases were shown to be involved in at least seven out of the top 10 causes of death in 2019. Patients with MetS are also at a heightened risk of severe morbidity and mortality in the present COVID-19 pandemic. Propolis with its antioxidant and anti-inflammatory properties is potentially useful in ameliorating the symptoms of MetS and its associated chronic diseases. The aim of this article is to provide a comprehensive review on propolis and its therapeutic benefit in MetS and its chronic diseases, with an emphasis on in vitro and in vivo studies, as well as human clinical trials. Moreover, the molecular and biochemical mechanisms of action of propolis are also discussed. Propolis inhibits the development and manifestation of MetS and its chronic diseases by inhibiting of the expression and interaction of advanced glycation end products (AGEs) and their receptors (RAGEs), inhibiting pro-inflammatory signaling cascades, and promoting the cellular antioxidant systems.

Propolis ethanolic extract has double-face in vitro effect on the planktonic growth and biofilm formation of some commercial probiotics

This study investigated the in vitro effect of propolis ethanolic extract (PEE) on planktonic growth and biofilm forming abilities of five commercial probiotics (Enterol, Protexin, Normaflore, BioGaia and Linex). Broth microdilution method was used to investigate the susceptibility of the microbes of five commercial probiotics to PEE. Crystal violet assay was used for the quantitative assessment of biofilm formation and mature biofilm eradication tests. Effect of PEE on autoaggregation ability and swarming motility of Normaflore microbes was determined. Planktonic forms of probiotics showed varied susceptibilities with minimal inhibitory concentration values in the range of 100-800 µg/mL of PEE. However, low PEE concentrations significantly enhanced the planktonic growth of Linex and BioGaia microbes. Biofilm studies revealed that Enterol and Protexin were non-biofilm formers, while BioGaia, Linex and Normaflore showed weak biofilms, which were inhibited by 12.5, 25, and 800 µg/mL of PEE, respectively. PEE revealed double-face effect on the biofilms of Normaflore and Linex, which were enhanced at low concentrations of PEE and inhibited at higher concentrations. Interestingly, Normaflore biofilms were shifted from weak to strong biofilms at low PEE concentrations (12.5, 25, and 50 µg/mL). In conclusion, PEE has strain dependent controversial effects on the planktonic growth and biofilm forming ability of the tested probiotics, although high concentrations have inhibitory effect on all of them, low concentrations may have strain dependent prebiotic effect.

Can Natural Polyphenols Help in Reducing Cytokine Storm in COVID-19 Patients?

SARS-CoV-2 first emerged in China during late 2019 and rapidly spread all over the world. Alterations in the inflammatory cytokines pathway represent a strong signature during SARS-COV-2 infection and correlate with poor prognosis and severity of the illness. The hyper-activation of the immune system results in an acute severe systemic inflammatory response named cytokine release syndrome (CRS). No effective prophylactic or post-exposure treatments are available, although some anti-inflammatory compounds are currently in clinical trials. Studies of plant extracts and natural compounds show that polyphenols can play a beneficial role in the prevention and the progress of chronic diseases related to inflammation. The aim of this manuscript is to review the published background on the possible effectiveness of polyphenols to fight SARS-COV-2 infection, contributing to the reduction of inflammation. Here, some of the anti-inflammatory therapies are discussed and although great progress has been made though this year, there is no proven cytokine blocking agents for COVID currently used in clinical practice. In this regard, bioactive phytochemicals such as polyphenols may become promising tools to be used as adjuvants in the treatment of SARS-CoV-2 infection. Such nutrients, with anti-inflammatory and antioxidant properties, associated to classical anti-inflammatory drugs, could help in reducing the inflammation in patients with COVID-19.

Galangin Inhibits LPS-Induced MMP-9 Expression via Suppressing Protein Kinase-Dependent AP-1 and FoxO1 Activation in Rat Brain Astrocytes

Purpose

Neuroinflammation, characterized by the increased expression of inflammatory proteins such as matrix metalloproteinases (MMPs), plays a critical role in neurodegenerative disorders. Lipopolysaccharide (LPS) has been shown to upregulate MMP-9 expression through the activation of various transcription factors, including activator protein 1 (AP-1) and forkhead box protein O1 (FoxO1). The flavonoid 3,5,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one (galangin) has been demonstrated to possess antioxidant and anti-inflammatory properties in various types of cells. Here, we investigated the mechanisms underlying the inhibitory effect of galangin on LPS-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells).

Methods

Pharmacological inhibitors and siRNAs were employed to explore the effects of galangin on LPS-challenged RBA-1 cells. Gelatin zymography, Western blotting, real-time PCR, and a luciferase reporter assay were used to detect MMP-9 activity, protein expression, mRNA levels, and promoter activity, respectively. The protein kinases involved in the LPS-induced MMP-9 expression were determined by Western blot. A chromatin immunoprecipitation (ChIP) assay was employed to evaluate the activity of c-Jun at the MMP-9 promoter.

Results

Galangin treatment attenuated the LPS-mediated induction of MMP-9 protein and mRNA expression, as well as the activity at the MMP-9 promoter. In addition, galangin exerted its inhibitory effects on MMP-9 expression through suppressing the LPS-stimulated activation of proline-rich tyrosine kinase (Pyk2), platelet-derived growth factor receptor beta (PDGFRβ), phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), and mitogen-activated protein kinases (MAPKs). Pretreatment with galangin attenuated the LPS-induced phosphorylation of c-Jun and FoxO1. LPS-induced cell migration was also suppressed by galangin pretreatment.

Conclusion

Galangin attenuates the LPS-induced inflammatory responses, including the induction of MMP-9 expression and cell migration, via inhibiting Pyk2/PDGFRβ/PI3K/Akt/mTOR/JNK1/JNK2 and p44/p42 MAPK cascade-dependent AP-1 and FoxO1 activities. These results provide new insights into the mechanisms through which galangin mitigates LPS-induced inflammatory responses, and suggest novel strategies for the management of LPS-related brain diseases.

Antioxidant and Anti-Inflammatory Activities of Safflower (Carthamus tinctorius L.) Honey Extract

Safflower honey is a unique type of monofloral honey collected from the nectar of Carthamus tinctorius L. in the Apis mellifera colonies of northwestern China. Scant information is available regarding its chemical composition and biological activities. Here, for the first time, we investigated this honey's chemical composition and evaluated its in vitro antioxidant and anti-inflammatory activities. Basic physicochemical parameters of the safflower honey samples in comparison to established quality standards suggested that safflower honeys presented a good level of quality. The in vitro antioxidant tests showed that extract from Carthamus tinctorius L. honey (ECH) effectively scavenged DPPH and ABTS⁺ free radicals. In lipopolysaccharides (LPS) activated murine macrophages inflammatory model, ECH treatment to the cells inhibited the release of nitric oxide and down-regulated the expressions of inflammatory-relating genes (iNOS, IL-1β, TNF-α and MCP-1). The expressions of the antioxidant genes TXNRD, HO-1, and NQO-1, were significantly boosted in a concentration-dependent manner. ECH decreased the phosphorylation of IκBα and inhibited the nuclear entry of the NF-κB-p65 protein, in LPS-stimulated Raw 264.7 cells, accompany with the increased expressions of Nrf-2 and HO-1, suggesting that ECH achieved the anti-inflammatory effects by inhibiting NF-κB signal transduction and boosting the antioxidant system via activating Nrf-2/HO-1 signaling. These results, taken together, indicated that safflower honey has great potential into developing as a high-quality agriproduct.

Impact of polyphenols in phagocyte functions

Polyphenols are a broad group of substances with potential health benefits found in plant species. Several of these compounds are capable of influencing the activation of intracellular signaling pathways, such as NF-kB, MAPK and JAK-STAT, responsible for the production of various inflammatory mediators such as tumor necrosis factor α (TNF-α) and interleukin 1 beta (IL-1β) and 12 (IL-12), enzymes involved in the production of reactive species such as inducible nitric oxide synthase (iNOS) and superoxide dehydrogenase (SOD), as well as enzymes involved in the production of eicosanoids, such as cyclooxygenase (COX) and lipoxygenase (LO). There is increased interest in the use of polyphenol-rich foods because of their immunomodulatory effect; however, the mechanisms used during macrophage responses are extremely complex and little is known about the effects of polyphenols on these cells. As such, this review summarizes the current view of polyphenol influences on macrophages.

A detailed computational investigation on the structural and spectroscopic properties of propolisbenzofuran B

This investigation deals with some structural and spectroscopic aspects of propolisbenzofuran B molecule as one of the most important bioactive molecules which exists in the bee propolis composition. FT-IR vibrational analysis carried-out at B3LYP/6-311++G(d,p) level of the theory. ¹H and ¹³C NMR chemical shift have been predicted with GIAO method. TD- DFT calculations have been established to predict the UV- Vis spectral analysis for propolisbenzofuran B molecule. The detailed structural analysis such as electronic characterization, HOMO and LUMO, DOS plot, Molecular Electronic Potential (MEP), Natural Bond Orbital (NBO) are performed and discussed for studied molecule.

Stronger antioxidant enzyme immunoreactivity of Populus tomentiglandulosa extract than ascorbic acid in rat liver and kidney

Objective(s):

Populus species have various pharmacological properties, including antioxidant activity. In this study, the effects of Populus tomentiglandulosa extract (PTE) on histopathology and antioxidant enzymes in the rat liver and kidney were examined.

Materials and Methods:

Sprague-Dawley rats were assigned to three groups; (1) normal diet fed group, (2) ascorbic acid-containing diet-fed group as a positive control, (3) PTE-containing diet-fed group. The histopathology in the rat liver and kidney was examined by hematoxylin and eosin staining. The effect of PTE was examined in the rat liver and kidney by immunohistochemistry for antioxidant enzymes, such as superoxide dismutases (SOD1 and SOD2), catalase (CAT), and glutathione peroxidase (GPx).

Results:

No marked histopathological alterations were observed in the liver and kidney of the PTE-containing diet-fed group. In the liver, the mean numbers of SOD1, SOD2, CAT, and GPx immunoreactive cells were significantly increased in the PTE-containing diet-fed rats, compared with those in the normal- and ascorbic acid-containing diet-fed rats. In the kidney, all SOD1, SOD2, CAT, and GPx immunoreactive structures were significantly increased in the PTE-containing diet-fed group, compared with those in the normal- and ascorbic acid-containing diet-fed groups.

Conclusion:

Results showed that PTE treatment significantly increased antioxidant enzymes in the rat liver and kidney, and we suggest that PTE might have hepato- and nephro-protective potentials against oxidative stress.

The Immunomodulatory and Anti-Inflammatory Role of Polyphenols

This review offers a systematic understanding about how polyphenols target multiple inflammatory components and lead to anti-inflammatory mechanisms. It provides a clear understanding of the molecular mechanisms of action of phenolic compounds. Polyphenols regulate immunity by interfering with immune cell regulation, proinflammatory cytokines' synthesis, and gene expression. They inactivate NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and modulate mitogen-activated protein Kinase (MAPk) and arachidonic acids pathways. Polyphenolic compounds inhibit phosphatidylinositide 3-kinases/protein kinase B (PI3K/AkT), inhibitor of kappa kinase/c-Jun amino-terminal kinases (IKK/JNK), mammalian target of rapamycin complex 1 (mTORC1) which is a protein complex that controls protein synthesis, and JAK/STAT. They can suppress toll-like receptor (TLR) and pro-inflammatory genes' expression. Their antioxidant activity and ability to inhibit enzymes involved in the production of eicosanoids contribute as well to their anti-inflammation properties. They inhibit certain enzymes involved in reactive oxygen species ROS production like xanthine oxidase and NADPH oxidase (NOX) while they upregulate other endogenous antioxidant enzymes like superoxide dismutase (SOD), catalase, and glutathione (GSH) peroxidase (Px). Furthermore, they inhibit phospholipase A2 (PLA2), cyclooxygenase (COX) and lipoxygenase (LOX) leading to a reduction in the production of prostaglandins (PGs) and leukotrienes (LTs) and inflammation antagonism. The effects of these biologically active compounds on the immune system are associated with extended health benefits for different chronic inflammatory diseases. Studies of plant extracts and compounds show that polyphenols can play a beneficial role in the prevention and the progress of chronic diseases related to inflammation such as diabetes, obesity, neurodegeneration, cancers, and cardiovascular diseases, among other conditions.

Potential Antinociceptive Effects of Chinese Propolis and Identification on Its Active Compounds

Propolis is an important bee product which has been applied to the treatment of several diseases. The aim of this study was to understand the material basis of Chinese propolis on pain relief; different Chinese propolis fractions (40W, 40E, 70E, and 95E raw propolis extracted followed by 40%, 70%, or 95% ethanol) were prepared, and their antinociceptive effects were evaluated. By analyzing using UPLC-Q-TOF-MS, we showed that 40W was rich in phenolic acids, like caffeic acid, while 40E, 70E, and 95E have relatively high levels in flavonoids, like galangin, pinocembrin, and chrysin. Notably, chrysin amounts in 70E and 95E are much higher than those in 40E fraction. Antinociceptive effects by these propolis fractions were evaluated in mice using acetic acid-induced writhing test, hot plate test, and tail immersion test, respectively. We noticed that only 40E fraction showed a significant reduction on acetic acid-induced writhing test. Importantly, in the hot plate test, all groups showed their effectiveness, except for the 70E group. We also noticed that 40W, 40E, and 95E administration caused an increase in the tail withdrawal latency of the mice. These data suggested that the different antinociceptive effects of different fractions from Chinese propolis extracts are directly link to their flavonoid composition.

Anti-inflammatory effects of Chinese propolis in lipopolysaccharide-stimulated human umbilical vein endothelial cells by suppressing autophagy and MAPK/NF-κB signaling pathway

This study aimed to investigate the possible benefits of Chinese poplar propolis (CP) in inhibiting inflammation using vascular endothelial cells (VECs) cultured in a nutrient-rich condition exposed to lipopolysaccharide (LPS). Cell proliferation was detected by sulforhodamine B assay and EdU kit. The production of reactive oxygen species (ROS) and level of mitochondrial membrane potential were determined with fluorescent probe DCHF and JC-1, respectively. Protein expression was examined by immunofluorescence staining and western blotting. The results showed that CP (6.25, 12.5, and 25 μg/mL) significantly reduced LPS-induced cytotoxicity, and when challenged with CP substantially suppressed ROS overproduction and protected mitochondrial membrane potential. CP treatment significantly inhibited autophagy by inhibiting LC3B distribution and accumulation, and elevating the p62 level in an mTOR-independent manner but mainly by suppressing the translocation of p53 from the cytoplasm to the nucleus. Furthermore, CP treatment markedly reduced protein levels of TLR4 at 12 and 24 h and significantly suppressed nuclear translocation of NF-κB p65 from cytoplasm to nucleus. In addition, CP treatment significantly reduced the phosphorylation of JNK, ERK1/2, and p38 MAPK. Our findings demonstrated that CP protects VECs from LPS-induced oxidative stress and inflammation, which might be associated with depressing autophagy and MAPK/NF-κB signaling pathway. The results provided novel insights for the potential use of nutrient-rich propolis against inflammation.

Serum Antioxidant Parameters are Significantly Increased in Patients with Type 2 Diabetes Mellitus after Consumption of Chinese Propolis: A Randomized Controlled Trial Based on Fasting Serum Glucose Level

INTRODUCTION

Propolis is a natural product with many biological activities. The present study was designed to evaluate the effects of Chinese propolis on glucose metabolism, antioxidant function, and inflammatory cytokines in patients with type 2 diabetes mellitus (T2DM).

METHODS

In the 18-week study, recruited T2DM patients were randomly divided into a Chinese propolis group (900 mg/day) (n = 31) and a control group (n = 30) according to fasting serum glucose levels at baseline.

RESULTS

At the end of the study, no significant difference was found between the groups in serum glucose, glycosylated hemoglobin, insulin, aldose reductase, or adiponectin. However, serum GSH, flavonoids, and polyphenols were significantly increased, and serum lactate dehydrogenase activity was significantly reduced in the Chinese propolis group. Meanwhile, serum IL-6 was significantly increased in the Chinese propolis group.

CONCLUSION

Chinese propolis is effective at improving antioxidant function in T2DM patients, partly by increasing serum antioxidant parameters.

Evidence for Anti-Pseudogymnoascus destructans (Pd) Activity of Propolis

White-nose syndrome (WNS) in bats, caused by Pseudogymnoascus destructans (Pd), is a cutaneous infection that has devastated North American bat populations since 2007. At present, there is no effective method for controlling this disease. Here, we evaluated the effect of propolis against Pd in vitro. Using Sabouraud dextrose agar (SDA) medium, approximately 1.7 × 10⁷ conidia spores of the Pd strain M3906-2/mL were spread on each plate and grown to form a consistent lawn. A Kirby-Bauer disk diffusion assay was employed using different concentrations of propolis (1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%), in plates incubated at 8 °C and 15 °C. At 8 °C and 15 °C, as the concentration of propolis increased, there was an increasing zone of inhibition (ZOI), reaching the highest degree at 10% and 25% concentrations, respectively. A germule suppression assay showed a similar effect on Pd conidia germination. A MALDI-TOF-MS analysis of propolis revealed multiple constituents with a potential anti-Pd activity, including cinnamic acid, p-coumaric acid, and dihydrochalcones, which could be further tested for their individual effects. Our study suggests that propolis or its individual constituents might be suitable products against Pd.

Dietary Propolis Ameliorates Dextran Sulfate Sodium-Induced Colitis and Modulates the Gut Microbiota in Rats Fed a Western Diet

Propolis is an important hive product and considered beneficial to health. However, evidence of its potential for improving gut health is still lacking. Here we use rats to examine whether dietary supplementation with propolis could be used as a therapy for ulcerative colitis. Rats were fed with a Western style diet alone (controls) or supplemented with different amounts of Chinese propolis (0.1%, 0.2%, and 0.3%) to examine effects on acute colitis induced by 3% dextran sulphate sodium (DSS) in drinking water. Propolis at 0.3%, but not lower levels, significantly improved colitis symptoms compared with the control group, with a less pronounced disease activity index (DAI) (p < 0.001), a significant increase in colon length/weight ratio (p < 0.05) and an improved distal colon tissue structure as assessed by histology. Although short chain fatty acid levels in digesta were not altered by propolis supplementation, 16S rRNA phylogenetic sequencing revealed a significant increase in gut microbial diversity after 21 days of 0.3% propolis supplementation compared with controls including a significant increase in bacteria belonging to the Proteobacteria and Acidobacteria phyla. This is the first study to demonstrate that propolis can attenuate DSS-induced colitis and provides new insight into diet-microbiota interactions during inflammatory bowel disease.

Antioxidant Activity of Quercetin and Its Glucosides from Propolis: A Theoretical Study

Among the multiple components of propolis, flavonoids contribute greatly to the antioxidant activities of propolis. Flavonoids mainly exist in the form of sugar-conjugated derivatives. Quercetin glycosides represent the predominant flavonoid fraction in propolis. In this work, density functional theory (DFT) calculations were applied to analyze the antioxidative properties of quercetin and its glucosides in the gas and in the liquid phase (ethanol, water). Three main antioxidant mechanisms, hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) were used to analyze the antioxidative capacity of the investigated compounds. Solvent effects dominantly affect SET-PT and SPLET. Thus, the thermodynamically preferred mechanism can be altered. HAT and SPLET are the thermodynamically dominant mechanisms in gas and solvent phases, respectively. Therefore, in the gas phase, the sequence of the antioxidative capacity is similar with the bond dissociation enthalpy values: quercetin > quercetin-5-O-glucoside > quercetin-7-O-glucoside > quercetin-3-O-glucoside > quercetin-3'-O-glucoside > quercetin-4'-O-glucoside. While, in the solvent phases, the sequence is similar with the proton affinity values: quercetin-4'-O-glucoside > quercetin-5-O-glucoside > quercetin > quercetin-3-O-glucoside > quercetin-7-O-glucoside > quercetin-3'-O-glucoside. OH groups in B-ring and C-ring contribute mainly to the antioxidative activities of quercetin and glucosides compared with A-ring.

Potential Protective Effects of Bioactive Constituents from Chinese Propolis against Acute Oxidative Stress Induced by Hydrogen Peroxide in Cardiac H9c2 Cells

Chinese propolis (CP) is known as a health food but its beneficial effects in protecting cardiomyocytes remain elusive. Here, we investigated the effects of CP and its active compounds on hydrogen peroxide (H₂O₂) induced rats cardiomyocytes (H9c2) oxidative injury. Cell viability decreases induced by H₂O₂ were mitigated by different CP extracts using various solvents. From these active fractions, six active compounds were separated and identified. Among tested isolated compound, the cytoprotective activities of three caffeates, caffeic acid phenethyl ester (CAPE), benzyl caffeate (BZC), and cinnamyl caffeate (CNC), exerted stronger effects than chrysin, pinobanksin, and 3,4-dimethoxycinnamic acid (DMCA). These three caffeates also increased H9c2 cellular antioxidant potential, decreased intracellular calcium ion ([Ca²⁺]_i) level, and prevented cell apoptosis. Overall, the cardiovascular protective effects of the CP might be attributed to its caffeates constituents (CAPE, BZC, and CNC) and provide evidence for its usage in complementary and alternative medicine.

Veronicastrum axillare Alleviates Lipopolysaccharide-Induced Acute Lung Injury via Suppression of Proinflammatory Mediators and Downregulation of the NF-κB Signaling Pathway

Veronicastrum axillare is a traditional medical plant in China which is widely used in folk medicine due to its versatile biological activities, especially for its anti-inflammatory effects. However, the detailed mechanism underlying this action is not clear. Here, we studied the protective effects of V. axillare against acute lung injury (ALI), and we further explored the pharmacological mechanisms of this action. We found that pretreatment with V. axillare suppressed the release of proinflammatory cytokines in the serum of ALI mice. Histological analysis of lung tissue demonstrated that V. axillare inhibited LPS-induced lung injury, improved lung morphology, and reduced the activation of nuclear factor-κB (NF-κB) in the lungs. Furthermore, the anti-inflammatory actions of V. axillare were investigated in vitro. We observed that V. axillare suppressed the mRNA expression of interleukin-1β (IL-1β), IL-6, monocyte chemotactic protein-1 (MCP-1), cyclooxygenase-2 (COX-2), and tumor necrosis factor-α (TNF-α) in RAW264.7 cells challenged with LPS. Furthermore, pretreatment of V. axillare in vitro reduced the phosphorylation of p65 and IκB-α which is activated by LPS. In conclusion, our data firstly demonstrated that the anti-inflammatory effects of V. axillare against ALI were achieved through downregulation of the NF-κB signaling pathway, thereby reducing the production of inflammatory mediators.

In Vitro Anti-Inflammatory Effects of Three Fatty Acids from Royal Jelly

Trans-10-hydroxy-2-decenoic acid (10-H2DA), 10-hydroxydecanoic acid (10-HDAA), and sebacic acid (SEA) are the three major fatty acids in royal jelly (RJ). Previous studies have revealed several pharmacological activities of 10-H2DA and 10-HDAA, although the anti-inflammatory effects and underlying mechanisms by which SEA acts are poorly understood. In the present study, we evaluated and compared the in vitro anti-inflammatory effects of these RJ fatty acids in lipopolysaccharide-stimulated RAW 264.7 macrophages. The results showed that 10-H2DA, 10-HDAA, and SEA had potent, dose-dependent inhibitory effects on the release of the major inflammatory-mediators, nitric oxide, and interleukin-10, and only SEA decreased TNF-α production. Several key inflammatory genes have also been modulated by these RJ fatty acids, with 10-H2DA showing distinct modulating effects as compared to the other two FAs. Furthermore, we found that these three FAs regulated several proteins involved in MAPK and NF-κB signaling pathways. Taken together, these findings provide additional references for using RJ against inflammatory diseases.

Effects of Chinese Propolis in Protecting Bovine Mammary Epithelial Cells against Mastitis Pathogens-Induced Cell Damage

Chinese propolis (CP), an important hive product, can alleviate inflammatory responses. However, little is known regarding the potential of propolis treatment for mastitis control. To investigate the anti-inflammatory effects of CP on bovine mammary epithelial cells (MAC-T), we used a range of pathogens to induce cellular inflammatory damage. Cell viability was determined and expressions of inflammatory/antioxidant genes were measured. Using a cell-based reporter assay system, we evaluated CP and its primary constituents on the NF-κB and Nrf2-ARE transcription activation. MAC-T cells treated with bacterial endotoxin (lipopolysaccharide, LPS), heat-inactivated Escherichia coli, and Staphylococcus aureus exhibited significant decreases in cell viability while TNF-α and lipoteichoic acid (LTA) did not. Pretreatment with CP prevented losses in cell viability associated with the addition of killed bacteria or bacterial endotoxins. There were also corresponding decreases in expressions of proinflammatory IL-6 and TNF-α mRNA. Compared with the mastitis challenged cells, enhanced expressions of antioxidant genes HO-1, Txnrd-1, and GCLM were observed in CP-treated cells. CP and its polyphenolic active components (primarily caffeic acid phenethyl ester and quercetin) had strong inhibitive effects against NF-κB activation and increased the transcriptional activity of Nrf2-ARE. These findings suggest that propolis may be valuable in the control of bovine mastitis.

Protection of Bovine Mammary Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Cell Damage by Resveratrol

The mammary epithelial cells (MECs) of high-producing dairy cows are likely to be subject to oxidative stress (OS) due to the intensive cell metabolism. The objectives of this study were to investigate the cytoprotective effects of resveratrol against hydrogen peroxide- (H2O2-) induced OS in cultured bovine MECs (MAC-T). Pretreatment of MAC-T cells with resveratrol could rescue the decrease in cell viability and resulted in lower intracellular reactive oxygen species (ROS) accumulation after H2O2 exposure. Resveratrol helped MAC-T cells to prevent H2O2-induced endoplasmic reticulum stress and mitochondria-related cell apoptosis. Moreover, resveratrol induced mRNA expression of multiple antioxidant defense genes in MAC-T cells under normal/oxidative conditions. Nuclear factor erythroid 2-related factor 2 (Nrf2) was required for the cytoprotective effects on MAC-T cells by resveratrol, as knockdown of Nrf2 significantly abolished resveratrol-induced cytoprotective effects against OS. In addition, by using selective inhibitors, we further confirmed that the induction of Nrf2 by resveratrol was mediated through the prolonged activation of PI3K/Akt and ERK/MAPK pathways but negatively regulated by p38/MAPK pathway. Overall, resveratrol has beneficial effects on bovine MECs redox balance and may be potentially used as a therapeutic medicine against oxidative insult in lactating animals.

Ethanol extract of propolis protects macrophages from oxidized low density lipoprotein-induced apoptosis by inhibiting CD36 expression and endoplasmic reticulum stress-C/EBP homologous protein pathway

Background

Ethanol extract of propolis (EEP), rich in flavones, has been known for various biological activities including antioxidant, antiinflammatory and antibiotic activities. Our previous studies have shown that EEP protects endothelial cells from oxidized low-density lipoprotein (ox-LDL)-induced apoptosis and inhibits atherosclerotic lesion development. In this present study, we explored the protective effect of EEP on ox-LDL-induced cytotoxicity in macrophages and specifically the endoplasmic reticulum (ER) stress-C/EBP homologous protein (CHOP) pathway-mediated apoptosis.

Methods

EEP was prepared and the total flavonoids content of EEP was determined by the colorimetric method of Chinese Standard (GB/T 20574-2006). The effects of EEP on lipid accumulation, cytotoxicity and apoptosis in RAW264.7 cells induced by ox-LDL or tunicamycin (TM, an ER stress inducer) were assayed using oil red O staining, MTT assay, flow cytometric analysis and so on. Immunofluorescence, Western blot and real time-PCR analysis were then used to further investigate the molecular mechanisms by which EEP protects macrophages from ox-LDL-induced apoptosis. 4-phenylbutyric acid (PBA), an ER stress inhibitor, was used as a positive control.

Results

EEP (7.5, 15 and 30 mg/L) not only attenuated ox-LDL-induced lipid accumulation in RAW264.7 macrophages in a dose-dependent manner but also inhibited the decreased cell viability and the increased lactate dehydrogenase (LDH) leakage, caspase-3 activation and apoptosis induced by ox-LDL or tunicamycin (TM, a classical ER stress inducer), which were similar to 4-phenylbutyric acid (PBA, an inhibitor of ER stress) treatment. In addition, like PBA, EEP significantly suppressed the ox-LDL- or TM-induced activation of ER stress signaling pathway including the phosphorylation of double-stranded RNA-activated protein kinase-like ER kinase (PERK) and eukaryotic translation initiation factor 2α (eIF2α) as well as upregulation of glucose regulated protein 78 (GRP78) and the pro-apoptotic protein CHOP. Furthermore, EEP significantly suppressed ox-LDL intake by macrophages and the upregulation of CD36 induced by ox-LDL.

Conclusion

These data indicate that EEP may protect macrophages from ox-LDL-induced apoptosis and the mechanism at least partially involves its ability to suppress the CD36-mediated ox-LDL intake and subsequent activation of ER stress-CHOP signalling pathway.

Anti-inflammatory effects of Huangqin tang extract in mice on ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

HuangqinTang (HQT) is a traditional Chinese formula which is composed of Scutellaria baicalensis Georgi, Paeonia lactiflora Pall, Glycyrrhiza uralensis Fisch, and Ziziphus jujube Mill. HQT has been used in China for a wide range of disorders, especially in gastrointestinal inflammation with symptoms of nausea, vomiting, diarrhea, abdominal cramps and so on.

AIM OF THE STUDY

To investigate the protective effects of HQT extract on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) induced colitis in mice.

MATERIALS AND METHODS

Different doses of HQT extract (1, 2 and 4 g/kg/day) and salicylazosulfapyridine (SASP, 500 mg/kg/day) were administered by gavage for 7 days after the induction of colitis with TNBS. The effects were studied by macroscopic score, histological analysis, immunohistochemical study of Cyclo-oxygenase-2 protein expression, as well as by determination of inflammation markers such as myeloperoxidase (MPO) and mRNA expression levels of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6.

RESULTS

In TNBS induced group, mice body weight decreased gradually and did not recover at the end of the experiment, as compared with that of control group (p<0.01). Edema and redness were also discovered in the colons profoundly and scores representing inflammation were all high in this group (p<0.01). The level of colonic MPO activity and the tissue levels of TNF-α, IL-1β and IL-6 were markedly increased (p<0.01). The mice treated with HQT extract and SASP recovered significantly compared with the TNBS group (p<0.01).

CONCLUSION

Our results suggested that the efficacy of HQT extract, especially at the higher dose, was analogous to that of SASP, which implicated its potential application as a natural alternative medicine in colitis treatment.

Comparisons of ethanol extracts of chinese propolis (poplar type) and poplar gums based on the antioxidant activities and molecular mechanism

The biological activities of propolis are varied from plant sources and the prominent antioxidant effects of Chinese propolis (poplar type) have been extensively reported. Oxidative stress is associated with inflammation and induces many diseases. In the study, to evaluate antioxidant capacities and clarify the underlying molecular mechanisms of ethanol extracts of Chinese propolis (EECP) and ethanol extracts of poplar gums (EEPG), we analyzed their compositions by HPLC, evaluating their free radical scavenging activities and reducing power by chemical analysis methods. Moreover, we studied the roles of EECP and EEPG on the elimination of ROS and expressions of antioxidant genes (HO-1, TrxR1, GCLM, and GCLC) in RAW264.7 cells. We further investigated the effects of MAPKs on the antioxidant genes expression by specific inhibitors. The nucleus translocation effects of Nrf2 were also measured by confocal microscopy analysis. The results indicated that EECP had higher TPC and FDC values but regarding TFC values were not significant. EECP also possessed more contents of 11 compounds than EEPG. Both phytochemical analysis and cell experiment reflected that EECP exerted stronger antioxidant activities than EEPG. EECP and EEPG enhanced endogenous antioxidant defenses by eliminating reactive oxygen species directly and activating Erk-Nrf2-HO1, GCLM, and TrxR1 signal pathways.

Hepatic oxidative stress and inflammatory responses with cadmium exposure in male mice

Cadmium (Cd), a non-essential heavy metal, is one of the major environmental contaminants with grave toxicological consequences globally. In the present study, the effects of Cd on hepatic oxidative stress and inflammatory responses in mice were evaluated. Male adult mice were orally exposed to 3, 10 and 30mg/L CdCl2 supplied in the drinking water for 7 and 21 days. Histopathological changes and the alterations of the main parameters related to oxidative stress and inflammatory responses in the liver were observed. Hepatic malondialdehyde (MDA) contents increased significantly after treatment with 30mg/L CdCl2 for 21 days, and the contents of glutathione (GSH) increased significantly in both 10 and 30mg/L CdCl2 treated groups. The hepatic activities of glutathione peroxidase (GPX), catalase (CAT) and glutathione S-transferase (GST) increased significantly after the treatment with 30mg/L CdCl2 for 21 days. In accordance with the enzyme activities, the transcription status of hepatic superoxide dismutase 1 (Sod1), superoxide dismutase 2 (Sod2), Cat, Gpx, Gstα1, glutathione synthetase (Gss), glutathione reductase (Gr) and heme oxygenase 1 (Ho1) were also increased by high dose (30mg/L) or long period (21 days) exposure. In addition, the serum levels of tumor necrosis factor α (TNFα), interleukin 6 (IL6) and interleukin 1β (IL1β) increased significantly in the groups treated with 30mg/L CdCl2 for 21 days. And the genes of TNFα, IL6, interleukin 1α (IL1α), inducible nitric oxide synthase (iNOS) and interferon γ (IFNγ) were also increased in the liver of mice when exposed to relative high dose of CdCl2 for 7 or 21 days. Taken together, the results of this study suggested that the exposure to Cd had the potential to induce immunotoxicity accompanied with oxidative stress in the liver of mice.

Recent advances in the chemical composition of propolis

Propolis is a honeybee product with broad clinical applications. Current literature describes that propolis is collected from plant resins. From a systematic database search, 241 compounds were identified in propolis for the first time between 2000 and 2012; and they belong to such diverse chemical classes as flavonoids, phenylpropanoids, terpenenes, stilbenes, lignans, coumarins, and their prenylated derivatives, showing a pattern consistent with around 300 previously reported compounds. The chemical characteristics of propolis are linked to the diversity of geographical location, plant sources and bee species.

In vitro cytotoxicity of Indonesian stingless bee products against human cancer cell lines

OBJECTIVE

To screen crude extracts of propolis, bee pollen and honey from four stingless bee species [Trigona incisa (T. incisa)], Timia apicalis, Trigona fusco-balteata and Trigona fuscibasis) native to East Kalimantan, Indonesia for cytotoxic activity against five human cancer cell lines (HepG2, SW620, ChaGo-I, KATO-III and BT474).

METHODS

All samples were extracted with methanol, and then subpartitioned with n-hexane and ethyl acetate. Each crude extract was screened at 20 µg/mL for in vitro cytotoxicity against the cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In addition, four previously shown bioactive components from propolis (apigenin, caffeic acid phenyl ester, kaempferol and naringenin) and two chemotherapeutic drugs (doxorubicin and 5-fluorouracil) were used to evaluate the sensitivity of the cell lines.

RESULTS

Overall, crude extracts from propolis and honey had higher cytotoxic activities than bee pollen, but the activity was dependent upon the extraction solvent, bee species and cell line. Propolis extracts from T. incisa and Timia apicalis showed the highest and lowest cytotoxic activity, respectively. Only the HepG2 cell line was broadly sensitive to the honey extracts. For pure compounds, doxorubicin was the most cytotoxic, the four propolis compounds the least, but the ChaGo-I cell line was sensitive to kaempferol at 10 µg/mL and KATO-III was sensitive to kaempferol and apigenin at 10 µg/mL. All pure compounds were effective against the BT474 cell line.

CONCLUSIONS

Propolis from T. incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines. Further study is required, including the isolation and characterization of the active antiproliferative agent(s).

Pinocembrin suppresses TGF-β1-induced epithelial-mesenchymal transition and metastasis of human Y-79 retinoblastoma cells through inactivating αvβ3 integrin/FAK/p38α signaling pathway

Background

Pinocembrin is the most abundant flavonoid in propolis. In this study, we investigated the antimetastatic effect of pinocembrin on TGF-β1-induced epithelial-mesenchymal transition (EMT) and metastasis of human Y-79 retinoblastoma cells.

Results

Firstly, the results showed that pinocembrin significantly suppresses the TGF-β1-induced abilities of the invasion and migration of Y-79 cells under non-cytotoxic concentration. Pinocembrin decreased TGF-β1-induced expression of vimentin, N-cadherin, αv and β3 integrin in Y-79 cells. Molecular data also showed pinocembrin inhibits the activation of focal adhesion kinase (FAK) and p38α signal involved in the downregulation of enzyme activities, protein and messenger RNA levels of matrix metalloproteinase-2/9 (MMP-2/-9) induced by TGF-β1. Next, pinocembrin also strongly inhibited the degradation of inhibitor of kappaBα (IκBα) and the nuclear levels of nuclear factor kappa B (NF-κB). Also, a dose-dependent inhibition on the binding ability of NF-κB was further observed under pinocembrin treatment.

Conclusions

Presented results indicated that pinocembrin inhibits TGF-β1-induced epithelial-mesenchymal transition (EMT) and metastasis of Y-79 cells by inactivating the αvβ3 integrin/FAK/p38α signaling pathway. Thus, our findings point to the anticancer potential of pinocembrin against retinoblastoma cells.

Anti-inflammatory effects of ethanol extracts of Chinese propolis and buds from poplar (Populus×canadensis)

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis is used widely in a number of cultures as a folk medicine and is gaining wider recognition for its potential therapeutic use, due to its wide range of biological properties and pharmacological activities, especially its anti-inflammatory effects. Despite an increasing number of studies focused on the biological activities of propolis together with its botanical sources, studies on Chinese propolis are insufficient. This study was designed to investigate the anti-inflammatory properties of ethanol extracts from Chinese propolis (EECP) and poplar buds (EEPB) from Populus×canadensis Moench (Salicaceae family).

MATERIALS AND METHODS

Phytochemical analysis of EECP and EEPB was performed via total phenolic and flavonoid content measurements followed by high-performance liquid chromatography (HPLC) analysis. DPPH and ABTS free-radical scavenging methods were used to evaluate their anti-oxidant properties. The anti-inflammatory effects of EECP and EEPB were investigated in vitro by evaluating their modulating effects on the key inflammatory cytokines and mediators in LPS/IFN-γ co-stimulated RAW 264.7 cells and by measuring nuclear factor (NF)-κB activation in TNF-α or IL-1β stimulation HEK 293 cells using reporter gene assays. Their effects on acute inflammatory symptoms (LPS-induced endotoxemia and acute pulmonary damage) were also examined in mice.

RESULTS

EECP and EEPB exhibited strong free-radical scavenging activity and significant in vitro anti-inflammatory effects by modulating key inflammatory mediators of mRNA transcription, inhibiting the production of specific inflammatory cytokines, and blocking the activation of nuclear factor (NF)-κB. The administration of EECP and EEPB (25 and 100 mg/kg) provided significant protective effects by attenuating lung histopathological changes and suppressing the secretion of LPS-stimulated inflammatory cytokines, such as interleukin-6 (IL-6), IL-10, MCP-1, TNF-α and IL-12p70 production in endotoxemic mice.

CONCLUSIONS

The results presented here reveal the potent anti-inflammatory properties of Chinese propolis and poplar buds, and provide biological information for developing suitable substitute(s) for propolis in the prevention and treatment of inflammatory diseases.

Identification of catechol as a new marker for detecting propolis adulteration

Adulteration of propolis with poplar extract is a serious issue in the bee products market. The aim of this study was to identify marker compounds in adulterated propolis, and examine the transformation of chemical components from poplar buds to propolis. The chemical profiles of poplar extracts and propolis were compared, and a new marker compound, catechol, was isolated and identified from the extracts of poplar buds. The polyphenol oxidase, catechol oxidase, responsible for catalyzing oxidation of catechol was detected in poplar buds and propolis. The results indicate catechol can be used as a marker to detect propolis adulterated with poplar extract.

Propolis Reduces Phosphatidylcholine-Specific Phospholipase C Activity and Increases Annexin a7 Level in Oxidized-LDL-Stimulated Human Umbilical Vein Endothelial Cells

To understand the mechanisms underlying the regulating dyslipidemia action of Chinese propolis and Brazilian green propolis, we investigated their effects on phosphatidylcholine-specific phospholipase C (PC-PLC) activity and annexin a7 (ANXA7) level which play crucial roles in the control of the progress of atherosclerosis. Furthermore, active oxygen species (ROS) levels, nuclear factor-KappaB p65 (NF-κB p65), and mitochondrial membrane potential (MMP) were also investigated in oxidized-LDL- (ox-LDL-) stimulated human umbilical vein endothelial cells (HUVECs). Our data indicated that the treatment of both types of propolis 12.5 μg/mL significantly increased cell viability and attenuated apoptosis rate, increased ANXA7 level, and decreased PC-PLC activity. Both types of propolis also inhibited ROS generation as well as the subsequent MMP collapse, and NF-κB p65 activation induced by ox-LDL in HUVECs. Our results also indicated that Chinese propolis and Brazilian green propolis had similar biological activities and prevented ox-LDL induced cellular dysfunction in HUVECs.

Effects of 6-Hydroxyflavone on Osteoblast Differentiation in MC3T3-E1 Cells

Osteoblast differentiation plays an essential role in bone integrity. Isoflavones and some flavonoids are reported to have osteogenic activity and potentially possess the ability to treat osteoporosis. However, limited information concerning the osteogenic characteristics of hydroxyflavones is available. This study investigates the effects of various hydroxyflavones on osteoblast differentiation in MC3T3-E1 cells. The results showed that 6-hydroxyflavone (6-OH-F) and 7-hydroxyflavone (7-OH-F) stimulated ALP activity. However, baicalein and luteolin inhibited ALP activity and flavone showed no effect. Up to 50 μM of each compound was used for cytotoxic effects study; flavone, 6-OH-F, and 7-OH-F had no cytotoxicity on MC3T3-E1 cells. Moreover, 6-OH-F activated AKT and serine/threonine kinases (also known as protein kinase B or PKB), extracellular signal-regulated kinases (ERK 1/2), and the c-Jun N-terminal kinase (JNK) signaling pathways. On the other hand, 7-OH-F promoted osteoblast differentiation mainly by activating ERK 1/ 2 signaling pathways. Finally, after 5 weeks of 6-OH-F induction, MC3T3-E1 cells showed a significant increase in the calcein staining intensity relative to merely visible mineralization observed in cells cultured in the osteogenic medium only. These results suggested that 6-OH-F could activate AKT, ERK 1/2, and JNK signaling pathways to effectively promote osteoblastic differentiation.

Modulation of immune function by polyphenols: possible contribution of epigenetic factors

Several biological activities have been described for polyphenolic compounds, including a modulator effect on the immune system. The effects of these biologically active compounds on the immune system are associated to processes as differentiation and activation of immune cells. Among the mechanisms associated to immune regulation are epigenetic modifications as DNA methylation of regulatory sequences, histone modifications and posttranscriptional repression by microRNAs that influences the gene expression of key players involved in the immune response. Considering that polyphenols are able to regulate the immune function and has been also demonstrated an effect on epigenetic mechanisms, it is possible to hypothesize that there exists a mediator role of epigenetic mechanisms in the modulation of the immune response by polyphenols.

Chemical Composition and Anti-Inflammatory Effect of Ethanolic Extract of Brazilian Green Propolis on Activated J774A.1 Macrophages

The aim of this study was to investigate the chemical composition and anti-inflammatory effect of ethanolic extract of Brazilian green propolis (EEP-B) on LPS + IFN-γ or PMA stimulated J774A.1 macrophages. The identification and quantification of phenolic compounds in green propolis extract were performed using HPLC-DAD and UPLC-Q-TOF-MS methods. The cell viability was evaluated by MTT and LDH assays. The radical scavenging ability was determined using DPPH^• and ABTS^•+. ROS and RNS generation was analyzed by chemiluminescence. NO concentration was detected by the Griess reaction. The release of various cytokines by activated J774A.1 cells was measured in the culture supernatants using a multiplex bead array system based on xMAP technology. Artepillin C, kaempferide, and their derivatives were the main phenolics found in green propolis. At the tested concentrations, the EEP-B did not decrease the cell viability and did not cause the cytotoxicity. EEP-B exerted strong antioxidant activity and significantly inhibited the production of ROS, RNS, NO, cytokine IL-1α, IL-1β, IL-4, IL-6, IL-12p40, IL-13, TNF-α, G-CSF, GM-CSF, MCP-1, MIP-1α, MIP-1β, and RANTES in stimulated J774A.1 macrophages. Our findings provide new insights for understanding the anti-inflammatory mechanism of action of Brazilian green propolis extract and support its application in complementary and alternative medicine.