Suppression of interleukin 17 production by Brazilian propolis in mice with collagen-induced arthritis

Propolis and Their Active Constituents for Chronic Diseases

Propolis is a mass of chemically diverse phytoconstituents with gummy textures that are naturally produced by honeybees upon collection of plant resins for utilization in various life processes in beehives. Since ancient times, propolis has been a unique traditional remedy globally utilized for several purposes, and it has secured value in pharmaceutical and nutraceutical areas in recent years. The chemical composition of propolis comprises diverse constituents and deviations in the precise composition of the honeybee species, plant source used for propolis production by bees, climate conditions and harvesting season. Over 300 molecular structures have been discovered from propolis, and important classes include phenolic acids, flavonoids, terpenoids, benzofurans, benzopyrene and chalcones. Propolis has also been reported to have diverse pharmacological activities, such as antidiabetic, anti-inflammatory, antioxidant, anticancer, immunomodulatory, antibacterial, antiviral, antifungal, and anticaries. As chronic diseases have risen as a global health threat, abundant research has been conducted to track propolis and its constituents as alternative therapies for chronic diseases. Several clinical trials have also revealed the potency of propolis and its constituents for preventing and curing some chronic diseases. This review explores the beneficial effect of propolis and its active constituents with credible mechanisms and computational studies on chronic diseases.

Propolis anti-inflammatory effects on MAGE-1 and retinoic acid-treated dendritic cells and on Th1 and T regulatory cells

Background

Propolis exhibits huge potential in the pharmaceutical industry. In the present study, its effects were investigated on dendritic cells (DCs) stimulated with a tumor antigen (MAGE-1) and retinoic acid (RA) and on T lymphocytes to observe a possible differential activation of T lymphocytes, driving preferentially to Th1 or Treg cells.

Methods

Cell viability, lymphocyte proliferation, gene expression (T-bet and FoxP3), and cytokine production by DCs (TNF-α, IL-10, IL-6 and IL-1β) and lymphocytes (IFN-γ and TGF-β) were analyzed.

Results

MAGE-1 and RA alone or in combination with propolis inhibited TNF-α production and induced a higher lymphoproliferation compared to control, while MAGE-1 + propolis induced IL-6 production. Propolis in combination with RA induced FoxP3 expression. MAGE-1 induced IFN-γ production while propolis inhibited it, returning to basal levels. RA inhibited TGF-β production, what was counteracted by propolis.

Conclusion

Propolis affected immunological parameters inhibiting pro-inflammatory cytokines and favoring the regulatory profile, opening perspectives for the control of inflammatory conditions.

Effect of propolis on Th2 and Th17 cells: interplay with EtxB- and LPS-treated dendritic cells

Dendritic cells (DCs) are antigen-presenting cells that drive the differentiation of T CD4+ cells into different profiles according to the nature of the antigen or immunomodulator. Propolis is a resinous product made by bees that has numerous pharmacological properties, including an immunomodulatory action. To assess whether propolis can modulate the activation of CD4+ T cells by stimulating DCs with heat-labile enterotoxin B subunit (EtxB) or lipopolysaccharide (LPS), we aimed to elucidate the mechanisms affected by propolis in the differential activation of T lymphocytes. Cell viability, lymphocyte proliferation, gene expression (GATA-3 and RORc), and cytokine production (interleukin (IL)-4 and IL-17A) were analyzed. Propolis, EtxB, and LPS induced a higher lymphoproliferation compared with the control. Propolis induced GATA-3 expression and, in combination with EtxB, maintained the baseline levels. Propolis alone or in combination with LPS inhibited RORc expression. EtxB alone and in combination with propolis increased IL-4 production. Propolis in combination with LPS prevented LPS-induced IL-17A production. These results opened perspectives for the study of biological events that may be favored by propolis by promoting Th2 activation or helping in the treatment of inflammatory conditions mediated by Th17 cells.

Allergic Inflammation: Effect of Propolis and Its Flavonoids

The incidence of allergic diseases and their complications are increasing worldwide. Today, people increasingly use natural products, which has been termed a "return to nature". Natural products with healing properties, especially those obtained from plants and bees, have been used in the prevention and treatment of numerous chronic diseases, including allergy and/or inflammation. Propolis is a multi-component resin rich in flavonoids, collected and transformed by honeybees from buds and plant wounds for the construction and adaptation of their nests. This article describes the current views regarding the possible mechanisms and multiple benefits of flavonoids in combating allergy and allergy-related complications. These benefits arise from flavonoid anti-allergic, anti-inflammatory, antioxidative, and wound healing activities and their effects on microbe-immune system interactions in developing host responses to different allergens. Finally, this article presents various aspects of allergy pathobiology and possible molecular approaches in their treatment. Possible mechanisms regarding the antiallergic action of propolis on the microbiota of the digestive and respiratory tracts and skin diseases as a method to selectively remove allergenic molecules by the process of bacterial biotransformation are also reported.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by artepillin C, a major component of Brazilian green propolis

OBJECTIVES

In this report, we attempt to clarify the immune modulatory effects of Brazilian green propolis (BGP) and its major component, artepillin C, on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells. We also estimate the physiological mechanism affecting artepillin C's upon the cells.

METHODS

Male C3H/HeN mouse spleen cells stimulated by antiCD3 monoclonal antibody were co-cultured with BGP, artepillin C, and HC030031, a transient receptor potential ankyrin 1 (TRPA1) Ca²⁺ channel antagonist. The synthesis of interferon (IFN)-γ, interleukin (IL)-6, IL-17, IL-4, IL-10, and IL-2 was assayed by enzyme-linked immunoassay. The expression of IL-2 mRNA and the protein product were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively.

RESULTS

The production of IL-2 was markedly enhanced, while that of IL-4 and IL-10 was not significantly affected; by contrast, the production of IFN-γ, IL-6, and IL-17 was significantly reduced in the antibody-stimulated spleen cells treated with BGP at a non-cytostatic concentration. These effects were reproduced in the cells treated with artepillin C. The expression of IL-2 mRNA was unaffected; however, that of the protein was significantly enhanced in the artepillin C-treated cells compared to untreated control cells. The enhancement of protein expression and the production of IL-2 by artepillin C was significantly alleviated by adding HC030031.

CONCLUSIONS

Artepillin C is an important regulator of cytokine synthesis from activated spleen cells. The agent specifically augmented the expression of IL-2 via the Ca²⁺-permeable cation channel, TRPA1, at least in part, at the translational or secretion levels.

Does propolis have any effect on rheumatoid arthritis? A review study

Rheumatoid arthritis (RA) is a chronic autoimmune disease in which inflammation and oxidative stress play a key role in its pathophysiology. Complementary therapies along with medications may be effective in the control of RA. Propolis is a natural substance extracted from beehives, which have confirmed anti-inflammatory and antioxidant effects. The present study aimed to review the possible effects of propolis on inflammation, oxidative stress, and lipid profile in patients with RA. English articles in online databases such as PubMed‑Medline, AMED, Google Scholar, EMBASE, Scopus, and Web of Science databases were searched. Pieces of evidence show that supplementation with propolis may have therapeutic effects on RA patients. Due to increased inflammation and oxidative stress in the affected joints of RA patients, propolis could inhibit the inflammatory cascades by inhibiting the nuclear factor kappa B pathway and reducing reactive oxygen species, malondialdehyde, and interleukin-17 by increasing some antioxidants. Therefore, inflammation and pain reduce, helping improve and control RA in patients. Further investigations are required with larger sample sizes and different doses of propolis to demonstrate the definite effects of propolis on various aspects of RA.

From propolis to nanopropolis: An exemplary journey and a paradigm shift of a resinous substance produced by bees

Propolis, a natural resinous mixture produced by honey bees is poised with diverse biological activities. Owing to the presence of flavonoids, phenolic acids, terpenes, and sesquiterpenes, propolis has garnered versatile applications in pharmaceutical industry. The biopharmaceutical issues associated with propolis often beset its use as being too hydrophobic in nature; it is not absorbed in the body well. To combat the problem, various nanotechnological approaches for the development of novel drug delivery systems are generally applied to improve its bioavailability. This paradigm shift and transition of conventional propolis to nanopropolis are evident from the literature wherein a multitude of studies are available on nanopropolis with improved bioavailability profile. These approaches include preparation of gold nanoparticles, silver nanoparticles, magnetic nanoparticles, liposomes, liquid crystalline formulations, solid lipid nanoparticles, mesoporous silica nanoparticles, etc. Nanopropolis has further been explored to assess the potential benefits of propolis for the development of futuristic useful products such as sunscreens, creams, mouthwashes, toothpastes, and nutritional supplements with improved solubility, bioavailability, and penetration profiles. However, more high-quality clinical studies assessing the effects of propolis either alone or in combination with synthetic drugs as well as natural products are warranted and its safety needs to be firmly established.

Anti-Viral and Immunomodulatory Properties of Propolis: Chemical Diversity, Pharmacological Properties, Preclinical and Clinical Applications, and In Silico Potential against SARS-CoV-2

Propolis, a resin produced by honeybees, has long been used as a dietary supplement and folk remedy, and more recent preclinical investigations have demonstrated a large spectrum of potential therapeutic bioactivities, including antioxidant, antibacterial, anti-inflammatory, neuroprotective, immunomodulatory, anticancer, and antiviral properties. As an antiviral agent, propolis and various constituents have shown promising preclinical efficacy against adenoviruses, influenza viruses, respiratory tract viruses, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), human immunodeficiency virus (HIV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over 300 chemical components have been identified in propolis, including terpenes, flavonoids, and phenolic acids, with the specific constituent profile varying widely according to geographic origin and regional flora. Propolis and its constituents have demonstrated potential efficacy against SARS-CoV-2 by modulating multiple pathogenic and antiviral pathways. Molecular docking studies have demonstrated high binding affinities of propolis derivatives to multiple SARS-CoV-2 proteins, including 3C-like protease (3CLpro), papain-like protease (PLpro), RNA-dependent RNA polymerase (RdRp), the receptor-binding domain (RBD) of the spike protein (S-protein), and helicase (NSP13), as well as to the viral target angiotensin-converting enzyme 2 (ACE2). Among these compounds, retusapurpurin A has shown high affinity to 3CLpro (ΔG = -9.4 kcal/mol), RdRp (-7.5), RBD (-7.2), NSP13 (-9.4), and ACE2 (-10.4) and potent inhibition of viral entry by forming hydrogen bonds with amino acid residues within viral and human target proteins. In addition, propolis-derived baccharin demonstrated even higher binding affinity towards PLpro (-8.2 kcal/mol). Measures of drug-likeness parameters, including metabolism, distribution, absorption, excretion, and toxicity (ADMET) characteristics, also support the potential of propolis as an effective agent to combat COVID-19.

Double-blinded randomized controlled trial to reveal the effects of Brazilian propolis intake on rheumatoid arthritis disease activity index; BeeDAI

Background and aims

Brazilian propolis reportedly contributed to suppressing disease activity in a mouse model of rheumatoid arthritis (RA), suggesting new treatment options using Brazilian propolis. However, only results from animal experiments have been available, and the suppressive effects of Brazilian propolis on disease activity in humans with RA remain unknown. The purpose of this study was to clinically validate how Brazilian propolis intake changes disease activity in RA patients.

Methods

This study was conducted as a multicenter, double-blinded, randomized, placebo-controlled, parallel-group study of 80 women with RA (median age, 61.5 years; interquartile range, 56.0 to 67.3 years) showing moderate disease activity on Disease Activity Score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR). Test tablets containing Brazilian propolis were used in Group P (40 patients), and Brazilian propolis-free placebo tablets were used as control in Group C (40 patients). Group P received 5 tablets of propolis (508.5 mg of propolis) daily, and Group C received 5 tablets of placebo daily. The intervention lasted 24 weeks, with change in DAS28-ESR set as the primary endpoint. As secondary endpoints, other disease activity assessment (DAS28 using C-reactive protein, simplified disease activity index, clinical disease activity index), ultrasonographic evaluation of synovitis, activities of daily living, quality of life, changes in cytokine levels, and adverse events over the course of the study were also assessed. Data were statistically analyzed by analysis of covariance.

Results

No significant differences in the primary endpoint were identified between groups (Group P vs Group C, effect: 0.14, 95% confidence interval: -0.21 to 0.49, p = 0.427). Likewise, no significant differences were seen between groups for any secondary endpoints. The adverse event rate during the study period was 28% in Group P and 33% in Group C.

Conclusions

Brazilian propolis exerted no effects on disease activity in patients with RA.

Propolis antiviral and immunomodulatory activity: a review and perspectives for COVID-19 treatment

OBJECTIVES

Viral outbreaks are a frequent concern for humans. A great variety of drugs has been used to treat viral diseases, which are not always safe and effective and may induce adverse effects, indicating the need for new antiviral drugs extracted from natural sources. Propolis is a bee-made product exhibiting many biological properties. An overview of viruses, antiviral immunity, propolis safety and its immunomodulatory and antiviral action is reported, as well as perspectives for coronavirus disease 2019 (COVID-19) treatment. PubMed platform was used for data collection, searching for the keywords "propolis", "virus", "antiviral", "antimicrobial" and "coronavirus".

KEY FINDINGS

Propolis is safe and exerts antiviral and immunomodulatory activity; however, clinical trials should investigate its effects on individuals with viral diseases, in combination or not with antiviral drugs or vaccines.

SUMMARY

Regarding COVID-19, the effects of propolis should be investigated directly on the virus in vitro or on infected individuals alone or in combination with antiviral drugs, due to its immunomodulatory and anti-inflammatory action. Propolis administration simultaneously with vaccines should be analyzed, due to its adjuvant properties, to enhance the individuals' immune response. The search for therapeutic targets may be useful to find out how propolis can help to control COVID-19.

Pharmacokinetics and metabolism of cinnamic acid derivatives and flavonoids after oral administration of Brazilian green propolis in humans

Brazilian green propolis (BGP) has chemical compounds from botanical origin that are mainly cinnamic acid derivatives (artepillin C, baccharin, and drupanin) and flavonoids (kaempferide and 6-methoxykaempferide). These compounds are expected to play an important role in the pharmacological activities of BGP. However, there is little known about the pharmacokinetics and metabolism of these compounds after oral administration of BGP. The aim of this study is to investigate the pharmacokinetics and metabolism of BGP components in humans. Twelve volunteers received 3 capsules containing 360 mg of BGP ethanol extract powder. Plasma samples were collected before and up to 24 h after the intake of BGP capsules. The collected plasma samples with or without hydrolysis by the deconjugating enzyme were analyzed by LC/MS/MS. After enzymatic hydrolysis, the C_max values of artepillin C and drupanin, which were detected mainly in plasma after ingestion of BGP capsules, were 1255 ± 517 and 2893 ± 711 nM, respectively, of which 89.3% and 88.2% were found to be the phenolic glucuronide conjugate. This is the first time that the pharmacokinetics of the BGP components of human metabolites have been reported. Our results could provide useful information for the design and interpretation of studies to investigate the mechanisms and pharmacological effects of BGP.

Broad-spectrum pharmacological activity of Australian propolis and metabolomic-driven identification of marker metabolites of propolis samples from three continents

Propolis is a by-product of honeybee farming known for its broad therapeutic benefits around the world and is extensively used in the health food and beverage industry. Despite Australia being one of the world's megadiverse countries with rich flora and fauna, Australian propolis samples have not been explored adequately with most in vitro and in vivo studies centred on their Brazilian and Chinese counterparts. In view of this, our study was designed to investigate the chemical composition and anti-proliferative, antibacterial, antifungal, anti-inflammatory and antioxidant properties of Australian propolis (AP-1) extract to draw a comparison with Brazilian (BP-1) and Chinese propolis (CP-1) extracts. The AP-1 extract displayed significantly greater anti-proliferative activity against the MCF7 and the MDA-MB-231 metastatic breast adenocarcinoma cell lines compared to BP-1 and CP-1 (p < 0.05). Similar trends were also observed in the antibacterial (Escherichia coli and Staphylococcus aureus), anti-inflammatory (lipopolysaccharide-induced RAW264.7 macrophages) and antioxidant assays (ABTS, DPPH and CUPRAC) with AP-1 exhibiting more potent activity than BP-1 and CP-1. The ultra-high performance liquid chromatography (UPLC) coupled with quadrupole high-resolution time of flight mass spectrometry (qTOF-MS) and chemometrics implementing unsupervised PCA and supervised OPLS-DA analyses of the propolis samples from Australia, China and Brazil revealed 67 key discriminatory metabolites belonging to seven main chemical classes including flavonoids, triterpenes, acid derivatives, stilbenes, steroid derivatives, diterpenes and miscellaneous compounds. Additionally, seven common phenolic compounds were quantified in the samples. Further mechanistic studies are necessary to elucidate the modes of action of Australian propolis for its prospective use in the food, nutraceutical and pharmaceutical industries.

Traditional and modern management strategies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a serious disorder of the joints affecting 1 or 2% of the population aged between 20 and 50 years worldwide. RA is the foremost cause of disability in developing and Western populations. It is an autoimmune disease-causing inflammation and pain involving synovial joints. Pro-inflammatory markers, including cytokines, such as interleukin -1 (IL-1), IL-6, IL-7, IL-8, and tumor necrosis factor-α (TNF-α) are involved in RA. RA treatment involves TNF-α blockade, B cell therapy, IL-1 and IL-6 blockade, and angiogenesis inhibition. Synthetic drugs available for the treatment of RA include disease-modifying anti-rheumatic drugs (DMARD), such as cyclophosphamide, sulfasalazine, methotrexate, nonsteroidal anti-inflammatory drugs (NSAIDs), and intramuscular gold. These agents induce adverse hepatorenal effects, hypertension, and gastric ulcers. We found that patients diagnosed with chronic pain, as in RA, and those refractory to contemporary management are most likely to seek traditional medicine. Approximately 60-90% of patients with arthritis use traditional medicines. Therefore, the efficacy and safety of these traditional medicines need to be established. The treatment for RA entails a comprehensive multidisciplinary strategy to reduce pain and inflammation and to restore the activity of joints. The potential medicinal plants exhibiting anti-arthritic and anti-rheumatic pharmacological activity are reviewed here.

Tylophora hirsuta (Wall.) Extracts Ameliorate Diabetes Associated with Inflammation in Alloxan-induced Diabetic Rats

BACKGROUND

Tylophora hirsuta (Wall) has long been used as traditional medicine for the treatment of diabetes. The current study is designed to evaluate the anti-diabetic and anti-inflammatory activity of different extracts of aerial parts of Tylophora hirsuta.

METHODS

Sequential maceration was conducted to obtain extracts. Total phenolic contents were determined by the Folin-Ciocalteau method. The anti-oxidant activity was assessed by DPPH free radical scavenging assay. The extracts were tested for its inhibitory activity against α-amylase in-vitro. In-vivo anti-diabetic assay was conducted using alloxan-induced diabetic model and OGTT was conducted on normal rats. ELISA was used to determine the pro-inflammatory cytokines (TNF-α and IL-6). The polyphenolic composition of the extract was analyzed using an HPLC system.

RESULTS

Aqueous extract exhibited highest total phenolic contents (985.24± 3.82 mg GAE/100 g DW), antioxidant activity (IC50 = 786.70 ± 5.23 μg/mL), and alpha-amylase inhibition (IC50 =352.8 μg/mL). The aqueous extract of Tylophora hirsuta showed remarkable in-vivo anti-diabetic activity. Results were compared with standard drug glibenclamide. Alloxan induced diabetic mediated alterations in liver function enzymes, renal function determinants, and lipid parameters were significantly restored in aqueous extract treated diabetic rats. A significant reduction in pro-inflammatory cytokines (p<0.001) was observed when compared to the control group. HPLC analysis confirms the presence of quercetin, gallic acid, cinnamic acid, and p-coumaric acid.

CONCLUSION

These results showed that Tylophora hirsuta possesses strong anti-diabetic and anti-inflammatory potentials and justify its folklore use for the management of diabetes.

Salt-dependent hypertension and inflammation: targeting the gut-brain axis and the immune system with Brazilian green propolis

Systemic arterial hypertension (SAH) is a major health problem around the world and its development has been associated with exceeding salt consumption by the modern society. The mechanisms by which salt consumption increase blood pressure (BP) involve several homeostatic systems but many details have not yet been fully elucidated. Evidences accumulated over the last 60 decades raised the involvement of the immune system in the hypertension development and opened a range of possibilities for new therapeutic targets. Green propolis is a promising natural product with potent anti-inflammatory properties acting on specific targets, most of them participating in the gut-brain axis of the sodium-dependent hypertension. New anti-hypertensive products reinforce the therapeutic arsenal improving the corollary of choices, especially in those cases where patients are resistant or refractory to conventional therapy. This review sought to bring the newest advances in the field articulating evidences that show a cross-talking between inflammation and the central mechanisms involved with the sodium-dependent hypertension as well as the stablished actions of green propolis and some of its biologically active compounds on the immune cells and cytokines that would be involved with its anti-hypertensive properties.

A Herbal Mixture from Propolis, Pomegranate, and Grape Pomace Endowed with Anti-Inflammatory Activity in an In Vivo Rheumatoid Arthritis Model

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by the production of inflammatory factors. In order to overcome the side effects of currently used anti-inflammatory drugs, several attempts have been made to identify natural products capable of relieving RA symptoms. In this work, a herbal preparation consisting of propolis, pomegranate peel, and Aglianico grape pomace (PPP) extracts (4:1:1) was designed and evaluated for its effect on a murine collagen-induced arthritis (CIA) model. Firstly, the chemical contents of four different Italian propolis collected in the Campania region (Italy) were here reported for the first time. LC-MS analyses showed the presence of 38 constituents, identified in all propolis extracts, belonging to flavonoids and phenolic acids classes. The Pietradefusi extract was the richest one and thus was selected to design the PPP preparation for the in vivo assay. Our results highlight the impact of PPP on RA onset and progression. By using in vivo CIA models, the treatment with PPP resulted in a delayed onset of the disease and alleviated the severity of the clinical symptoms. Furthermore, we demonstrated that early PPP treatment was associated with a reduction in serum levels of IL-17, IL-1b, and IL-17–triggering cytokines.

Propolis: types, composition, biological activities, and veterinary product patent prospecting

Propolis is a resinous substance composed of a mixture of different plant parts and molecules secreted by bees. Chemically, it is defined as a complex matrix containing biologically active molecules with antibacterial, antifungal, antiviral, antiparasitic, hepatoprotective, and immunomodulatory activities. It is widely employed in cosmetic formulations and pharmaceutical products and is one of the most widely used natural products. However, the effects and strength of these biological activities depend on the chemical profile and composition of each propolis type. This composition is associated with the diversity of local flora, the place and period of collection, and the genetics of the bees. In this context, the objective of this review was to investigate the biological, chemical, and microbiological properties of propolis. A technological prospection was also performed on patents for products designed to be used in animal health. Our investigation shows that the literature contains diverse studies dedicated to comparing and describing the composition and therapeutic properties of propolis. These studies demonstrate the potential biological use of propolis in veterinary medicine, showing the applications of propolis extracts in different formulations. However, there are a low number of propolis-based veterinary products with a registered patent. Thus, the development of products based on propolis is a promising market to be exploited. © 2019 Society of Chemical Industry.

In Vitro Evaluation of the Potential Use of Propolis as a Multitarget Therapeutic Product: Physicochemical Properties, Chemical Composition, and Immunomodulatory, Antibacterial, and Anticancer Properties

Propolis is a resin that honeybees produce by mixing saliva and beeswax with exudate gathered from botanical sources. The present in vitro study investigated the potential use of propolis as a multitarget therapeutic product and the physicochemical properties, chemical composition, and immunomodulatory, antioxidant, antibacterial, and anticancer properties of a propolis extract from the northern Morocco region (PNM). Pinocembrin, chrysin, and quercetin were the main phenolic compounds of PNM as measured in HPLC. The PNM showed significant inhibitory effects against all tested Gram-positive and Gram-negative strains and showed high antioxidant activities by scavenging free radicals with IC50 (DPPH = 0.02, ABTS = 0.04, and FRAP = 0.04 mg/ml). In addition, PNM induced a dose-dependent cytostatic effect in MCF-7, HCT, and THP-1 cell lines at noncytotoxic concentrations with IC50 values of 479.22, 108.88, and 50.54 μg/ml, respectively. The production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was decreased in a dose-dependent manner in LPS-stimulated human peripheral blood mononuclear cells (PBMNCs), whereas the production of the anti-inflammatory interleukin-10 (IL-10) was increased in a dose-dependent manner reaching 15-fold compared to the levels measured in untreated PBMNCs. Overall, the results showed that the traditionally known multitarget therapeutic properties of the PNM seem to be mediated, at least in part, through cytostatic, antibacterial, and immunomodulatory effects.

Isolation, Identification, and Synthesis of a New Prenylated Cinnamic Acid Derivative from Brazilian Green Propolis and Simultaneous Quantification of Bioactive Components by LC-MS/MS

A new cinnamic acid derivative, (E)-3-[4-hydroxy-3-((E)-3-formyl-2-butenyl)phenyl]-2- propenoic acid (20) has been isolated from the ethanol extract of Brazilian green propolis along with three known cinnamic acid derivatives, 3,4-dihydroxy-5-prenyl-(E)-cinnamic acid (4), capillartemisin A (6), and 2,2-dimethylchromene-6-(E)-propenoic acid (8), and a flavonoid, dihydrokaempferide (16) by liquid-liquid participation, a series of column chromatography and preparative HPLC. Their structures have been determined by spectroscopic analyses and chemical synthesis of compound 20. The simultaneous quantification of 20 constituents, including 10 cinnamic acid derivatives, 7 flavonoids, and 3 caffeoylquinic acid derivatives, has also been developed and validated using LC-MS/MS. The new compound 20 was shown to activate PPAR α but not PPAR β or γ.

Brazilian propolis extract reduces intestinal barrier defects and inflammation in a colitic mouse model

Brazilian propolis is rich in cinnamic acid derivatives and reportedly reduces intestinal inflammation in rodents; however, the underlying mechanisms remain unclear. We hypothesized that the regulation of tight junction (TJ) barrier, Th17 cell differentiation, and/or, macrophage activation by cinnamic acid derivatives were involved in the propolis-mediated anti-inflammatory effect. Mice were orally administered 2% dextran sodium sulfate (DSS) in combination with either the feeding control or a diet containing 0.3% ethanol extract of Brazilian propolis for 9 days. DSS administration induced acute colitis in mice, whereas the propolis extract mitigated DSS-induced weight loss; colon shortening; increased plasma levels of lipopolysaccharide-binding protein; reduced expression of TJ proteins, such as zonula occludens, junctional adhesion molecule-A, occludin, and claudins; and increased expression of inflammatory cytokines, such as tumor necrosis factor (TNF) α, interleukin (IL) 6, and IL-17a. Cinnamic acid derivatives, such as artepillin C and caffeic acid phenethyl ester, present in the propolis extract suppressed the IL-17 production from cultured murine splenocytes through decreased retinoic acid-related orphan receptor gT expression. Baccharin, drupanin, and culifolin, which are also present in Brazilian propolis, reduced the TNF-α and/or IL-6 production by suppressing inflammatory signaling in murine RAW 264.7 macrophages. Taken together, the regulation of Th17 differentiation and macrophage activation by cinnamic acid derivatives, at least in part, contribute to the anti-inflammatory effect mediated by Brazilian propolis.

Green propolis extract promotes in vitro proliferation, differentiation, and migration of bone marrow stromal cells

BACKGROUND

Propolis is a resinous material extracted from bee glue with a complex chemical composition. The unique biological properties of propolis have led to its use in alternative medicine and as a nutritional supplement. Recent research shows that propolis could affect the immune system by decreasing the production of inflammatory cytokines and potentiating an effect on resident stem cells. The exact mechanism, however, is unknown. The goal of this study was to demonstrate whether green propolis extract affects any characteristic properties of mesenchymal stromal cells (MSCs)in vitro.

METHODS

The cytocompatibility of propolis extract and the proliferation of bone marrow mesenchymal stromal cells (BMMSCs) in the presence of propolis was evaluated by live/dead cell staining and MTS viability assay over a period of 3 days. Also, we evaluated the effect of propolis extract on trilineage differentiation and migration capacity of undifferentiated and differentiated BMMSCs.

RESULTS

Relative to the control, propolis extract resulted in a significant and linear increase in the proliferation of MSCs and inhibited the osteogenic differentiation of BMMSCs, while there was a potentiation of chondrogenesis and adipogenesis. Finally, in relevance to wound healing, an in vitro scratch assay demonstrated that the migratory potential of differentiated BMMSCs was enhanced in the presence of propolis.

CONCLUSION

We have demonstrated that propolis extract was not toxic to BMMSCs (<400 μg/ml), supported their proliferation, potentiated chondrogenic and adipogenic differentiation processes, and supported cell migrationin vitro. Most interestingly, there was a down-regulation of osteogenesis. These data support the use of propolis extract for enhanced cell proliferation and tissue regeneration; however, it warrants further investigation.

Propolis Exerts an Anti-Inflammatory Effect on PMA-Differentiated THP-1 Cells via Inhibition of Purine Nucleoside Phosphorylase

Previous research has shown that propolis has immunomodulatory activity. Propolis extracts from different geographic origins were assessed for their anti-inflammatory activities by investigating their ability to alter the production of tumour necrosis factor-α (TNF-α) and the cytokines interleukin-1β (IL-1β), IL-6 and IL-10 in THP-1-derived macrophage cells co-stimulated with lipopolysaccharide (LPS). All the propolis extracts suppressed the TNF-α and IL-6 LPS-stimulated levels. Similar suppression effects were detected for IL-1β, but the release of this cytokine was synergised by propolis samples from Ghana and Indonesia when compared with LPS. Overall, the Cameroonian propolis extract (P-C) was the most active and this was evaluated for its effects on the metabolic profile of unstimulated macrophages or macrophages activated by LPS. The levels of 81 polar metabolites were identified by liquid chromatography (LC) coupled with mass spectrometry (MS) on a ZIC-pHILIC column. LPS altered the energy, amino acid and nucleotide metabolism in THP-1 cells, and interpretation of the metabolic pathways showed that P-C reversed some of the effects of LPS. Overall, the results showed that propolis extracts exert an anti-inflammatory effect by inhibition of pro-inflammatory cytokines and by metabolic reprogramming of LPS activity in macrophage cells, suggesting an immunomodulatory effect.

Aspergillus fumigatus conidia stimulate lung epithelial cells (TC-1 JHU-1) to produce IL-12, IFNγ, IL-13 and IL-17 cytokines: Modulatory effect of propolis extract

Aspergillus fumigatus conidia are the most prevalent indoors fungal allergens. The interaction between Aspergillus antigens and lung epithelial cells (LECs) result in innate immune functions. The association between Aspergillus conidia and allergic reactions, like allergic bronchopulmonary aspergillosis (ABPA) and asthma have been repeatedly reported. Since conventional therapies for allergy and asthma are limited, finding new promising treatments are inevitable. This study was designed to evaluate the effect of A. fumigatus conidia on IL-12, IFNγ, IL-13 and IL-17 release from mouse LECs and to investigate the effect of propolis on cytokines modulation. Cells were divided to two groups, one was exposed to 3×10⁴ conidia of Aspergillus fumigatus and another group was treated by propolis (25μg/mL) as well as exposed to A. fumigatus conidia. Cytokines IL-13, IL-12, IFNγ and IL-17 were measured at times 0, 6 and 12hours after exposure using ELISA assay. The results indicated that A. fumigatus could increase the release of the cytokines with IL-13 and IL-17 being the most affected ones whilst treatment with propolis decreased the effects of A. fumigatus on IL-13 and IL-17 production. The results showed that propolis has down regulatory effects on Th2 cytokine, IL-13, and IL-17 production, whereas it caused a significant induction of IL-12, as an important Th1 cytokines by LECs. With respect to the obtained results, propolis extract might be contributed to decrease Th2 responses in allergic asthma phenomenon. However more investigations must be done in future to fully understand its efficacy.

The Role of IL-17 and Th17 Lymphocytes in Autoimmune Diseases

The end of twentieth century has introduced some changes into T helper (Th) cells division. The identification of the new subpopulation of T helper cells producing IL-17 modified model of Th1-Th2 paradigm and it was named Th17. High abilities to stimulate acute and chronic inflammation made these cells ideal candidate for crucial player in development of autoimmune disorders. Numerous publications based on animal and human models confirmed their pivotal role in pathogenesis of human systemic and organ-specific autoimmune diseases. These findings made Th17 cells and pathways regulating their development and function a good target for therapy. Therapies based on inhibition of Th17-dependent pathways are associated with clinical benefits, but on the other hand are frequently inducing adverse effects. In this review, we attempt to summarize researches focused on the importance of Th17 cells in development of human autoimmune diseases as well as effectiveness of targeting IL-17 and its pathways in pre-clinical and clinical studies.

Therapeutic potential of interleukin-17 in inflammation and autoimmune diseases

INTRODUCTION

Interleukin-17 (IL-17) is a proinflammatory cytokine that mainly produced by T helper 17 (Th17) cells. In this article, we discussed the role of IL-17 in inflammation and autoimmune diseases, and the therapeutic strategies targeting IL-17.

AREAS COVERED

In this article, we discussed the proinflammatory cytokine IL-17 and IL-17 receptors signals, and their regulation. IL-17 expression was abnormal in the bacterium, virus and fungus infection, and its higher level caused the tissue inflammation. IL-17 was involved in the pathological process of autoimmune diseases, such as systemic sclerosis, rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematosus, and IL-17 has been put as a therapeutic target in the clinic.

EXPERT OPINION

IL-17/IL-17R signals and their application in inflammation process still need to be explored. Therapeutic strategies targeting IL-17 in autoimmune diseases ameliorated the inadequate response to anti-TNF-α therapy.