Effects of propolis from different areas on mast cell degranulation and identification of the effective components in propolis

Antiviral action of aqueous extracts of propolis from Scaptotrigona aff. postica (Hymenoptera; Apidae) against Zica, Chikungunya, and Mayaro virus

The limited availability of antivirals for new highly pathogenic strains of virus has become a serious public health. Therefore, news products against these pathogens has become an urgent necessity. Among the multiple sources for news antibiotics and antivirals, insect exudates or their products has become an increasingly frequent option. Insects emerged 350 million years ago and have showed a high adaptability and resistance to the most varied biomes. Their survival for so long, in such different environments, is an indication that they have a very efficient protection against environmental infections, despite not having a developed immune system like mammals. Since the ancient civilizations, the products obtained from the bee have been of great pharmacological importance, being used as antimicrobial, anti-inflammatory, antitumor and several other functions. Investigations of biological activity of propolis have been carried out, mainly in the species Apis mellifera, and its product have showed activity against some important viruses. However, for the Meliponini species, known as stingless bees, there are few studies, either on their chemical composition or on their biological activities. The importance of studying these bees is because they come from regions with native forests, and therefore with many species of plants not yet studied, in addition to which they are regions still free of pesticides, which guarantees a greater fidelity of the obtained data. Previous studies by our group with crude hydroalcoholic extract of propolis demonstrated an intense antiviral activity against Herpes, influenza, and rubella viruses. In this work, we chose to use aqueous extracts, which eliminates the presence of other compounds besides those originally present in propolis, in addition to extracting substances different from those obtained in alcoholic extracts. Therefore, this study aimed to identify, isolate and characterize compounds with antiviral effects from aqueous propolis extracts from Scaptotrigona aff postica, in emerging viruses such as zicavirus, chikungunya, and mayaro virus. The evaluation of the antiviral activity of the crude and purified material was performed by reducing infectious foci in VERO cell cultures. The results obtained with crude propolis, indicate a high reduction of zica virus (64×) and mayaro (128×) when was used 10% v/v of propolis. The reduction of chikungunya virus was of 256 fold, even when was used 5% v/v of propolis. The chemical characterization of the compounds present in the extracts was performed by high-pressure liquid chromatography. Through the purification of propolis by HPLC and mass spectrometry, it was possible to identify and isolate a peak with antiviral activity. This substance showed activity against all viruses tested. When purified fraction was used, the reduction observed was of 16 fold for zicavirus, 32 fold for mayaro virus and 512 fold for chikungunya virus. Likewise, it was observed that the antiviral response was concentration dependent, being more intense when propolis was added 2 h after the viral infection. Now we are carrying out the chemical characterization of the purified compounds that showed antiviral action.

Quercetin and Kaempferol inhibit HMC-1 activation via SOCE/NFATc2 signaling and suppress hippocampal mast cell activation in lipopolysaccharide-induced depressive mice

OBJECTIVE AND DESIGN

Mast cells (MCs), as the fastest immune responders, play a critical role in the progression of neuroinflammation-related diseases, especially in depression. Quercetin (Que) and kaempferol (Kae), as two major diet-derived flavonoids, inhibit MC activation and exhibit significant antidepressant effect due to their anti-inflammatory capacity. The study aimed to explore the mechanisms of inhibitory effect of Que and Kae on MC activation, and whether Que and Kae suppress hippocampal mast cell activation in LPS-induced depressive mice.

SUBJECTS AND TREATMENT

In vitro assays, human mast cells (HMC-1) were pretreated with Que or Kae for 1 h, then stimulated by phorbol 12-myristate 13-acetate (PMA) and 2,5-di-t-butyl-1,4-benzohydroquinone (tBHQ) for 3 h or 12 h. In vivo assays, Que or Kae was administered by oral gavage once daily for 14 days and then lipopolysaccharide (LPS) intraperitoneally injection to induce depressive behaviors.

METHODS

The secretion and expression of TNF-α were determined by ELISA and Western blotting. The nuclear factor of activated T cells (NFAT) transcriptional activity was measured in HMC-1 stably expressing NFAT luciferase reporter gene. Nuclear translocation of NFATc2 was detected by nuclear protein extraction and also was fluorescently detected in HMC-1 stably expressing eGFP-NFATc2. We used Ca2+ imaging to evaluate changes of store-operated calcium entry (SOCE) in HMC-1 stably expressing fluorescent Ca2+ indicator jGCamP7s. Molecular docking was used to assess interaction between the Que or Kae and calcium release-activated calcium modulator (ORAI). The  hippocampal mast cell accumulation and activation  were detected by toluidine blue staining and immunohistochemistry with β-tryptase.

RESULTS

In vitro assays of HMC-1 activated by PtBHQ (PMA and tBHQ), Que and Kae significantly decreased expression and secretion of TNF-α. Moreover, NFAT transcriptional activity and nuclear translocation of NFATc2 were remarkably inhibited by Que and Kae. In addition, the Ca2+ influx mediated by SOCE was suppressed by Que, Kae and the YM58483 (ORAI inhibitor), respectively. Importantly, the combination of YM58483 with Que or Kae had no additive effect on the inhibition of SOCE. The molecular docking also showed that Que and Kae both exhibit high binding affinities with ORAI at the same binding site as YM58483. In vivo assays, Que and Kae significantly reversed LPS-induced depression-like behaviors in mice, and inhibited hippocampal mast cell activation  in LPS-induced depressive mice.

CONCLUSIONS

Our results indicated that suppression of SOCE/NFATc2 pathway-mediated by ORAI channels may be the mechanism of inhibitory effect of Que and Kae on MC activation, and also suggested Que and Kae may exert the antidepressant effect through suppressing hippocampal mast cell activation.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

Therapeutic potential of propolis in alleviating inflammatory response and promoting wound healing in skin burn

Burns can cause inflammation and delayed healing, necessitating alternative therapies due to the limitations of conventional treatments. Propolis, a natural bee-produced substance, has shown promise in facilitating burn healing. This literature review provides a comprehensive overview of propolis' mechanisms of action, wound-healing properties, and its application in treating skin burns. Propolis contains bioactive compounds with antimicrobial, antioxidant, and anti-inflammatory properties, making it a promising candidate for managing skin burn injuries. It helps prevent infections, neutralize harmful free radicals, and promote a well-balanced inflammatory response. Moreover, propolis aids in wound closure, tissue regeneration, collagen synthesis, cellular proliferation, and angiogenesis, contributing to tissue regeneration and remodeling. The article discusses various propolis extracts, extraction methods, chemical composition, and optimized formulations like ointments and creams for burn wound treatment. Considerations regarding dosage and safety are addressed. Further research is needed to fully understand propolis' mechanisms, determine optimal formulations, and establish suitable clinical dosages. Nevertheless, propolis' natural origin and demonstrated benefits make it a compelling avenue for burn care exploration, potentially complementing existing therapies and improving burn management outcomes.

Propolis: Its Role and Efficacy in Human Health and Diseases

With technological advancements in the medicinal and pharmaceutical industries, numerous research studies have focused on the propolis produced by stingless bees (Meliponini tribe) and Apis mellifera honeybees as alternative complementary medicines for the potential treatment of various acute and chronic diseases. Propolis can be found in tropical and subtropical forests throughout the world. The composition of phytochemical constituents in propolis varies depending on the bee species, geographical location, botanical source, and environmental conditions. Typically, propolis contains lipid, beeswax, essential oils, pollen, and organic components. The latter include flavonoids, phenolic compounds, polyphenols, terpenes, terpenoids, coumarins, steroids, amino acids, and aromatic acids. The biologically active constituents of propolis, which include countless organic compounds such as artepillin C, caffeic acid, caffeic acid phenethyl ester, apigenin, chrysin, galangin, kaempferol, luteolin, genistein, naringin, pinocembrin, coumaric acid, and quercetin, have a broad spectrum of biological and therapeutic properties such as antidiabetic, anti-inflammatory, antioxidant, anticancer, rheumatoid arthritis, chronic obstruct pulmonary disorders, cardiovascular diseases, respiratory tract-related diseases, gastrointestinal disorders, as well as neuroprotective, immunomodulatory, and immuno-inflammatory agents. Therefore, this review aims to provide a summary of recent studies on the role of propolis, its constituents, its biologically active compounds, and their efficacy in the medicinal and pharmaceutical treatment of chronic diseases.

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.

Research Progress on Therapeutic Effect and Mechanism of Propolis on Wound Healing

Propolis is a kind of reduct collected by bees from various plant sources. Because propolis is a mixture, it has a variety of biological activities, excellent anti-inflammatory and bactericidal effects. Especially in the treatment of infectious wounds, acute wounds, burns, and scalds and promoting wound healing, more and more scientists began to apply it to the research field of wound healing. The standard preparation of propolis combined with other compound components has a safer and less toxic effect in the treatment of trauma. In order to more effectively use propolis products in wound treatment. This paper reviews the effect and treatment mechanism of propolis on different types of wound healing, as well as the synergistic effect of propolis and other compounds, in order to provide ideas for the further exploration of the biological activity and pharmacological function of propolis in the future, as well as its in-depth development in the field of wound healing. It will also provide a theoretical reference for the further development and utilization of propolis.

Computational Study of Asian Propolis Compounds as Potential Anti-Type 2 Diabetes Mellitus Agents by Using Inverse Virtual Screening with the DIA-DB Web Server, Tanimoto Similarity Analysis, and Molecular Dynamic Simulation

Propolis contains a wide range of pharmacological activities because of their various bioactive compounds. The beneficial effect of propolis is interesting for treating type-2 diabetes mellitus (T2DM) owing to dysregulation of multiple metabolic processes. In this study, 275 of 658 Asian propolis compounds were evaluated as potential anti-T2DM agents using the DIA-DB web server towards 18 known anti-diabetes protein targets. More than 20% of all compounds could bind to more than five diabetes targets with high binding affinity (<−9.0 kcal/mol). Filtering with physicochemical and pharmacokinetic properties, including ADMET parameters, 12 compounds were identified as potential anti-T2DM with favorable ADMET properties. Six of those compounds, (2R)-7,4′-dihydroxy-5-methoxy-8-methylflavone; (RR)-(+)-3′-senecioylkhellactone; 2′,4′,6′-trihydroxy chalcone; alpinetin; pinobanksin-3-O-butyrate; and pinocembrin-5-methyl ether were first reported as anti-T2DM agents. We identified the significant T2DM targets of Asian propolis, namely retinol-binding protein-4 (RBP4) and aldose reductase (AKR1B1) that have important roles in insulin sensitivity and diabetes complication, respectively. Molecular dynamic simulations showed stable interaction of selected propolis compounds in the active site of RBP4 and AKR1B1. These findings suggest that Asian propolis compound may be effective for treatment of T2DM by targeting RBP4 and AKR1B1.

Therapeutic and prophylactic effect of flavonoids in post-COVID-19 therapy

The high incidence of post-covid symptoms in humans confirms the need for effective treatment. Due to long-term complications across several disciplines, special treatment programs emerge for affected patients, emphasizing multidisciplinary care. For these reasons, we decided to look at current knowledge about possible long-term complications of COVID-19 disease and then present the effect of flavonoids, which could help alleviate or eliminate complications in humans after overcoming the COVID-19 infection. Based on articles published from 2003 to 2021, we summarize the flavonoids-based molecular mechanisms associated with the post-COVID-19 syndrome and simultaneously provide a complex view regarding their prophylactic and therapeutic potential. Review clearly sorts out the outcome of post-COVID-19 syndrome according particular body systems. The conclusion is that flavonoids play an important role in prevention of many diseases. We suggest that flavonoids as critical nutritional supplements, are suitable for the alleviation and shortening of the period associated with the post-COVID-19 syndrome. The most promising flavonoid with noteworthy therapeutic and prophylactic effect appears to be quercetin.

Anti-Allergic Properties of Propolis: Evidence From Preclinical and Clinical Studies

Allergic diseases are a global health burden with increasing prevalence. Side effects of available medications (antihistamines and steroids), lack of patients' perceived effectiveness and high cost of biologic therapies (omalizumab) are challenges to the clinical management of allergic diseases. As allergy symptoms persist for a long time, complementary and alternative medicine (CAM) such as propolis may be considered a potential prophylactic or therapeutic option to avoid long-term medication use. Propolis is a natural resinous substance produced by bees. Although propolis is well known to possess antioxidant, antimicrobial, and anticancer properties, its anti-allergic potential is not fully explored. Several preclinical studies demonstrated the therapeutic effects of propolis extracts against allergic inflammation, asthma, allergic rhinitis, atopic dermatitis, and food allergy, which may be partly attributed to their inhibitory effects on the activation of mast cells and basophils. Clinically, the consumption of propolis as a supplement or an adjunct therapy is safe and attenuates various pathological conditions in asthma. Such an approach may be adopted for atopic dermatitis and allergic rhinitis. Although flavonoids (chrysin, kaempferol, galangin, and pinocembrin) and cinnamic acid derivatives (artepillin C and caffeic acid phenethyl ester) can contribute to the anti-allergic activities, they may not be present in all propolis samples due to variations in the chemical composition. Future studies should relate the anti-allergic activity of propolis with its chemical contents. This mini-review summarizes and discusses existing preclinical and clinical studies reporting the anti-allergic activities of propolis to provide insights into its potential applications in allergic diseases.

Propolis suppresses cytokine production in activated basophils and basophil-mediated skin and intestinal allergic inflammation in mice

BACKGROUND

Propolis is a resinous mixture produced by honey bees that contains cinnamic acid derivatives and flavonoids. Although propolis has been reported to inhibit mast cell functions and mast cell-dependent allergic responses, the effect of propolis on basophil biology remains unknown. This study aimed to investigate the inhibitory effect of propolis on FcεRI-mediated basophil activation.

METHODS

To determine the inhibitory effect of propolis on basophil activation in vitro, cytokine production and FcεRI signal transduction were analyzed by ELISA and western blotting, respectively. To investigate the inhibitory effect of propolis in vivo, IgE-CAI and a food allergy mouse model were employed.

RESULTS

Propolis treatment resulted in the suppression of IgE/antigen-induced production of IL-4, IL-6 and IL-13 in basophils. Phosphorylation of FcεRI signaling molecules Lyn, Akt and ERK was inhibited in basophils treated with propolis. While propolis did not affect the basophil population in the treated mice, propolis did inhibit IgE-CAI. Finally, ovalbumin-induced intestinal anaphylaxis, which involves basophils and basophil-derived IL-4, was attenuated in mice prophylactically treated with propolis.

CONCLUSIONS

Taken together, these results demonstrate the ability of propolis to suppress IgE-dependent basophil activation and basophil-dependent allergic inflammation. Therefore, prophylactic treatment with propolis may be useful for protection against food allergic reactions in sensitive individuals.

New Insights for Red Propolis of Alagoas-Chemical Constituents, Topical Membrane Formulations and Their Physicochemical and Biological Properties

The main objectives of this study were to evaluate the chemical constitution and allergenic potential of red propolis extract (RPE). They were evaluated, using high performance liquid chromatography (HPLC) and the release of β-hexosaminidase, respectively. A plethora of biologically active polyphenols and the absence of allergic responses were evinced. RPE inhibited the release of β-hexosaminidase, suggesting that the extract does not stimulate allergic responses. Additionally, the physicochemical properties and antibacterial activity of hydrogel membranes loaded with RPE were analyzed. Bio-polymeric hydrogel membranes (M) were obtained using 5% carboxymethylcellulose (M1 and M2), 1.0% of citric acid (M3) and 10% RPE (for all). Their characterization was performed using thermal analysis, Fourier transform infrared (FTIR), total phenolic content, phenol release test and, antioxidant activity through 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and Ferric Reducing Antioxidant Power (FRAP). The latter appointed to the similar antioxidant capacity of the M1, M2 and M3. The degradation profiles showed higher thermostability to M3, followed by M2 and M1. The incorporation of RPE into the matrices and the crosslinking of M3 were evinced by FTIR. There were differences in the release of phenolic compounds, with a higher release related to M1 and lower in the strongly crosslinked M3. The degradation profiles showed higher thermostability to M3, followed by M2 and M1. The antibacterial activity of the membranes was determined using the disc diffusion assay, in comparison with controls, obtained in the same way, without RPE. The membranes elicited antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis, with superior performance over M3. The hydrogel membranes loaded with RPE promote a physical barrier against bacterial skin infections and may be applied in the wound healing process.

Effect of kaempferol on IgE-mediated anaphylaxis in C57BL/6 mice and LAD2 cells

BACKGROUND

Immunoglobulin E (IgE)-mediated mast cell (MC) activation is crucial in multiple allergic diseases. Parkinson disease protein 7 (DJ-1) and Lyn kinase were reported as the receptor-proximal events in IgE receptor (FcεRI) signals in human MC. Kaempferol, a natural flavonol mainly derived from the rhizome of traditional Chinese herb Kaempferia galanga L. (Zingiberaceae), has been known to inhibit allergic reactions, but it was limited to the receptor-distal signals on rat basophilic leukemia cells. A thorough investigation of the inhibitory effects of kaempferol on human MC has not been done.

PURPOSE

To investigate the inhibitory effects of kaempferol on IgE-mediated anaphylaxis in vivo and in human MCs, as well as the mechanism underlying its effects, especially the receptor-proximal signals.

METHODS

IgE-mediated passive cutaneous anaphylaxis and systemic anaphylaxis model were applied to elucidate the antiallergic activity of kaempferol in vivo. The degranulation assay, calcium imaging, the release of cytokines and chemokines on the laboratory of allergic disease 2 (LAD2) cells were used to evaluate the antiallergic effect of kaempferol in vitro. Western blot analysis was performed to investigate the DJ-1/Lyn signaling pathway and downstream molecules. Kinase activity assay, immunofluorescence, and molecular docking were conducted to confirm the influence of kaempferol on DJ-1/Lyn molecules.

RESULTS

Kaempferol dose-dependently attenuated ovalbumin/IgE-induced mice paw swelling, primary MC activation from paw skin, as well as rehabilitated the hypothermia, and reduced the serum concentrations of histamine, tumor necrosis factor-alpha, interleukin-8, and monocyte chemo-attractant protein-1. Additionally, kaempferol suppressed IgE-mediated LAD2 cell degranulation and calcium fluctuation. Remarkably, kaempferol was found to bind with DJ-1 protein, and initially prevented DJ-1 from translocating to the plasma membrane, thereby inhibited full activation of Lyn, and eventually restrained those receptor-distal signaling molecules, involved Syk, Btk, PLCγ, IP3R, PKC, MAPKs, Akt and NF-κB.

CONCLUSION

Kaempferol could be used as a DJ-1 modulator for preventing MC-mediated allergic disorders through attenuating Lyn activation.

Efficacy of Brazilian Propolis Supplementation for Japanese Lactating Women for Atopic Sensitization and Nonspecific Symptoms in Their Offspring: A Randomized, Double-Blind, Placebo-Controlled Trial

Propolis is a natural product collected from several plants by honeybees and mixed with beeswax and salivary enzymes. In animal models, propolis suppressed IgE-mediated allergies. However, there is no clinical evidence that propolis prevents human atopic sensitization, to the best of our knowledge. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to assess whether propolis supplementation for lactating women increases or decreases the level of total IgE and antigen-specific IgE in the serum of their offspring (i.e., atopic sensitization) at the time of their first birthday. In addition, whether propolis supplementation improves or worsens nonspecific symptoms (e.g., eczema) in the lactating women and their offspring was also investigated. This trial is registered with UMIN000020794. Eligible pairs of mothers and their offspring (n=80) were randomized to two groups: propolis (n=40) and placebo (n=40). Participants were evaluated every month, and 31 (78%) of the propolis group and 23 (58%) of the placebo group underwent blood tests at the first birthday of the offspring. Total IgE ≥ 10 U_A/ml was seen in 26 (84%) infants whose mothers were given propolis, which was not significantly different from the 19 (86%) given placebo (P=0.80). Total IgE as a continuous variable was not significantly different between the propolis and placebo groups (P=0.70). Antigen-specific IgE levels for mites, egg white, cow's milk, and wheat, as both dichotomous and continuous variables, were not significantly different between the two groups. Both in mothers and their offspring, there were no significant differences in the subjective improvements of nonspecific symptoms between the two groups. Except for one mother who had transient and mild nausea, none of the other mothers or their offspring developed severe adverse events during the follow-up period. In conclusion, compared with placebo, Brazilian propolis supplementation did not influence the risk of atopic sensitization in infants and neither did it improve nor worsen nonspecific symptoms in either mothers or their infants.

Effect of Royal Jelly and Brazilian Green Propolis on the Signaling for Histamine H1 Receptor and Interleukin-9 Gene Expressions Responsible for the Pathogenesis of the Allergic Rhinitis

The significant correlation between nasal symptom scores and level of histamine H₁ receptor (H1R) mRNA in nasal mucosa was observed in patients with pollinosis, suggesting that H1R gene is an allergic disease sensitive gene. We demonstrated that H1R and interleukin (IL)-9 gene are the allergic rhinitis (AR)-sensitive genes and protein kinase Cδ (PKCδ) signaling and nuclear factor of activated T-cells (NFAT) signaling are involved in their expressions, respectively. Honey bee products have been used to treat allergic diseases. However, their pathological mechanism remains to be elucidated. In the present study, we investigated the mechanism of the anti-allergic effect of royal jelly (RJ) and Brazilian green propolis (BGPP). Treatment with RJ and BGPP decreased in the number of sneezing on toluene 2,4-diissocyanate (TDI)-stimulated rats. The remarkable suppression of H1R mRNA in nasal mucosa was observed. RJ and BGPP also suppressed the expression of IL-9 gene. RJ and BGPP suppressed phorbol-12-myristate-13-acetate-induced Tyr³¹¹ phosphorylation of PKCδ in HeLa cells. In RBL-2H3 cells, RJ and BGPP also suppressed NFAT-mediated IL-9 gene expression. These results suggest that RJ and BGPP improve allergic symptoms by suppressing PKCδ and NFAT signaling pathways, two important signal pathways for the AR pathogenesis, and suggest that RJ and BGPP could be good therapeutics against AR.

Mexican Propolis: A Source of Antioxidants and Anti-Inflammatory Compounds, and Isolation of a Novel Chalcone and ε-Caprolactone Derivative

The propolis produced by bees are used in alternative medicine for treating inflammation, and infections, presumably due to its antioxidant properties. In this context, five propolis from México were investigated to determine their inhibitory lipid peroxidation properties. The ethyl acetate extract from a red propolis from Chiapas State (4-EAEP) was the most potent (IC₅₀ = 1.42 ± 0.07 μg/mL) in the TBARS assay, and selected for further studies. This extract afforded two new compounds, epoxypinocembrin chalcone (6), and an ε-caprolactone derivative (10), as well as pinostrobin (1), izalpinin (2), cinnamic acid (3), pinocembrin (4), kaempherol (5), 3,3-dimethylallyl caffeate in mixture with isopent-3-enyl caffeate (7a + 7b), 3,4-dimethoxycinnamic acid (8), rhamnetin (9) and caffeic acid (11). The HPLC profile, anti-mycobacterial, and antioxidant properties of this extract was also determined. Most of the isolated compounds were also tested by inhibition of reactive oxygen species (ROS) in challenged mouse bone marrow-derived mast cells (BMMCs), and DPPH. Their anti-inflammatory activity was evaluated by TPA, and MPO (myeloperoxidase) activity by ear edema test in mice. The most potent compounds were 7a + 7b in the TBARS assay (IC₅₀ = 0.49 ± 0.06 μM), and 2 which restored the ROS baseline (3.5 μM). Our results indicate that 4-EAEP has anti-oxidant, and anti-inflammatory properties due to its active compounds, suggesting it has anti-allergy and anti-asthma potential.

Potential role of propolis in wound healing: Biological properties and therapeutic activities

Propolis is a resinous mixture that honey bees collect from the tree buds, sap flows, or other botanical sources. The chemical composition of propolis varies and depends on the geographical area, time of collection, seasonality, illumination, altitude, and food availability during propolis exploitation. The goal of this review is to discuss important concepts including mechanisms of action and therapeutic activities of propolis. The PubMed, ScienceDirect, and Cochrane Library databases were searched for the literature published from January the 1st 2000 to October the 1st 2017. Sixteen animals and three clinical studies were included. A quantitative and qualitative review was performed on the clinical trials and the animal studies were comprehensively overviewed. In this study, the clinical trials have been combined and the results were provided as meta-analysis. Propolis is a non-toxic natural product; however some cases of allergy and contact dermatitis to this compound have been described mainly among beekeepers. An important factor in impaired wound healing is biofilm formation; propolis as an anti-microbial agent can reduce biofilm generation and result in accelerated healing processes. Most of the in vivo studies on various wound models suggested the beneficial roles of propolis on experimental wound healing and this has also been approved in the clinical trial studies. However, there is a lack of information concerning, dose, side effects and clinical effectiveness of propolis on wounds. As the effectiveness of propolis between different products is variable, more characterizations should be done and future investigations comparing different propolis based products and characterization of their specific roles on different models of wounds are highly appreciated.

Anti-inflammatory activity of flavonoids in Nepalese propolis is attributed to inhibition of the IL-33 signaling pathway

Propolis has been used in folk medicine to improve health and prevent inflammatory diseases; however, the components that exhibit its anti-inflammatory activity remain unknown. We herein investigated the effects of flavonoids isolated from Nepalese propolis on the IL-33 signaling pathway to clarify the anti-inflammatory mechanism involved. Of the 8 types of flavonoids isolated from Nepalese propolis, 4 types of compounds, such as 3',4'-dihydroxy-4-methoxydalbergione, 4-methoxydalbergion, cearoin, and chrysin, markedly inhibited the IL-33-induced mRNA expression of inflammatory genes including IL-6, TNFα and IL-13 in bone marrow-derived mast cells (BMMC). These four flavonoids also inhibited the IL-33-induced activation of nuclear factor κB (NF-κB), which was consistent with their inhibitory effects on cytokine expression. The effects of these flavonoids are attributed to inhibition of IL-33-induced activation of IKK, which leads to the degradation of IκBα and nuclear localization of NF-κB. On the other hand, other flavonoids isolated from Nepalese propolis, such as isoliquiritigenin, plathymenin, 7-hydroxyflavanone, and (+)-medicarpin, had no effect on the IL-33 signaling pathway or cytokine expression. Therefore, these results indicate that 3',4'-dihydroxy-4-methoxydalbergione, 4-methoxydalbergion, cearoin, and chrysin are the substances responsible for the anti-inflammatory activity of Nepalese propolis.

Oral administration of royal jelly restores tear secretion capacity in rat blink-suppressed dry eye model by modulating lacrimal gland function

Tears are secreted from the lacrimal gland (LG), a dysfunction in which induces dry eye, resulting in ocular discomfort and visual impairment. Honey bee products are used as a nutritional source in daily life and medicine; however, little is known about their effects on dry eye. The aim of the present study was to investigate the effects of honey bee products on tear secretion capacity in dry eye. We selected raw honey, propolis, royal jelly (RJ), pollen, or larva from commercially available honey bee products. Tear secretion capacity was evaluated following the oral administration of each honey bee product in a rat blink-suppressed dry eye model. Changes in tear secretion, LG ATP content, and LG mitochondrial levels were measured. RJ restored the tear secretion capacity and decrease in LG ATP content and mitochondrial levels to the largest extent. Royal jelly can be used as a preventative intervention for dry eye by managing tear secretion capacity in the LG.

Antioxidant effects of propolis on carp Cyprinus carpio exposed to arsenic: biochemical and histopathologic findings

Propolis, a resinous material produced by worker bees from the leaf buds and exudates of plants, is reported to possess various therapeutic properties. The aim of this study was to investigate the effects of propolis on biochemical parameters and histopathologic findings in carp Cyprinus carpio L. exposed to arsenic. A sublethal concentration of arsenic (0.01 mg l-1) and/or 10 mg l-1 propolis were administered to fish for 1 wk. Catalase (CAT) activities and malondialdehyde (MDA) levels were determined in liver, gill and muscle tissues in control, arsenic only, propolis only and arsenic+propolis treatment groups. Results showed that CAT activity decreased in the arsenic group compared to the control and propolis groups. CAT activity in the arsenic+propolis group was significantly higher compared to the arsenic group. MDA levels in fish exposed to 0.01 mg l-1 arsenic significantly increased compared to the control group. However, MDA levels in the arsenic+propolis group were significantly lower compared to the arsenic group. Histopathological changes in the liver, gill and muscle tissues of carp were examined by light microscopy: various changes were observed in all tissues of fish in the arsenic group. Propolis showed important antioxidant effects against arsenic toxicity in all fish tissues.

Galangin attenuates mast cell-mediated allergic inflammation

A great number of people are suffering from allergic inflammatory disease such as asthma, atopic dermatitis, and sinusitis. Therefore discovery of drugs for the treatment of these diseases is an important subject in human health. In this study, we investigated anti-allergic inflammatory effect of galangin and underlying mechanisms of action using in vitro and in vivo models. Galangin inhibited histamine release by the reduction of intracellular calcium in phorbol 12-mystate 13-acetate plus calcium ionophore A23187-stimulated human mast cells (HMC-1). Galangin decreased expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-8. The inhibitory effect of galangin on theses pro-inflammatory cytokines was related with c-Jun N-terminal kinases, and p38 mitogen-activated protein kinase, nuclear factor-κB, and caspase-1. Furthermore, galangin attenuated IgE-mediated passive cutaneous anaphylaxis and the expression of histamine receptor 1 at the inflamed tissue. The inhibitory effects of galangin were more potent than cromolyn, a known anti-allergic drug. Our results showed that galangin down-regulates mast cell-derived allergic inflammatory reactions by blocking histamine release and expression of pro-inflammatory cytokines. In light of in vitro and in vivo anti-allergic inflammatory effects, galangin could be a beneficial anti-allergic inflammatory agent.

Immunostimulant effect of Egyptian propolis in rabbits

The present experiment was conducted to study the effect of ethanolic extract of Egyptian propolis given alone or in combination with inactivated Pasteurella multocida vaccine on rabbits challenged with a virulent strain of Pasteurella multocida. Fifty-six New-Zealand rabbits, 6–8 weeks old and non-vaccinated against pasteurellosis, were randomly divided into eight equal groups. The first group was kept as a control for the experiment. The other groups received different treatments with propolis extract, inactivated vaccine, or both. The experiment continued for seven weeks during which clinical signs, body weight, and mortality rate were monitored, and blood samples were collected weekly for evaluating the leukogram, serum biochemistry, and immune response in all groups of animals. At the end of the seventh week, the animals were subjected to challenge with a virulent strain of Pasteurella multocida. Two weeks later, tissue specimens were collected from different organs for histopathological examination. Results showed that rabbits of the groups treated with both propolis and the vaccine by different routes appeared healthy after challenge. It has been concluded that alcoholic extract of propolis administrated in combination with inactivated Pasteurella multocida vaccine has no adverse effects on the general health conditions and enhances immune response in rabbits.

Analytical methods applied to diverse types of Brazilian propolis

Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen) can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting.Propolis has been used as a popular remedy for several centuries for a wide array of ailments. Its antimicrobial properties, present in propolis from different origins, have been extensively studied. But, more recently, anti-parasitic, anti-viral/immune stimulating, healing, anti-tumor, anti-inflammatory, antioxidant and analgesic activities of diverse types of Brazilian propolis have been evaluated. The most common methods employed and overviews of their relative results are presented.

Chrysin suppresses mast cell-mediated allergic inflammation: involvement of calcium, caspase-1 and nuclear factor-κB

A great number of people are suffering from allergic inflammatory diseases such as asthma, atopic dermatitis, and sinusitis. Therefore discovery of drugs for the treatment of these diseases is an important subject in human health. Chrysin (5,7-dihydroxyflavone) is a natural flavonoid contained in propolis, blue passion flower, and fruits. Several studies reported that chrysin has beneficial effects including anti-tumor and anti-oxidant activities. The aim of the present study was to elucidate whether chrysin modulates the allergic inflammatory reaction and to study its possible mechanisms of action using mast cell-based in vitro and in vivo models. Chrysin inhibited immediate-type systemic hypersensitivity and serum histamine release. Chrysin attenuated immunoglobulin E-mediated local anaphylaxis. These inhibitory effects of chrysin on the systemic and local allergic reaction were more potent than cromolyn, a known anti-allergic drug. Chrysin reduced histamine release from mast cells. The inhibitory effect of chrysin on the histamine release was mediated by the modulation of intracellular calcium. In addition, chrysin decreased gene expression of pro-inflammatory cytokines such as, tumor necrosis factor-α, IL (interleukin)-1β, IL-4, and IL-6 in mast cells. The inhibitory effect of chrysin on the pro-inflammatory cytokine was nuclear factor-κB and caspase-1 dependent. Our findings provide evidence that chrysin inhibits mast cell-derived allergic inflammatory reactions by blocking histamine release and pro-inflammatory cytokine expression, and suggest the mechanisms of action. Furthermore, in vivo and in vitro anti-allergic inflammatory effect of chrysin suggests a possible therapeutic application of this agent in allergic inflammatory diseases.