Effects of Brazilian green propolis and artepillin C on collagen metabolism and fibroblast behaviors: Implications for skin wound healing.

In this study, we aimed to evaluate the preventive effects of Brazilian green propolis on equine herpes virus (EHV)-induced encephalitis in a hamster model. We first investigated the antiviral activity of Brazilian green propolis against EHV-9, and then, examined the effects of propolis on the kinetics and production of cytokines. Sixtyfive male, Syrian hamsters were divided into two treatment groups and control group. The 1st group is a control. The second group was infected intranasally with 50 μl of EHV-9 [3 × 104 plaque-forming units (pfu)] without propolis treatment. The third group received propolis at 500 mg/kg of ethanol extract of Brazilian green propolis by a gavage for 7 days, followed by intranasal inoculation with 50 μl of EHV-9 (3 × 104 pfu). Pre-treatment with propolis was not effective in preventing EHV-9-induced encephalitis via intranasal route. This speculation is supported by similar clinical signs and similar immunohistochemistry based on viral antigen distribution in the brain of infected hamsters in groups 2 and 3 from 3rd day post inoculation (dpi). There were significant increases in cerebral mRNA levels of IL-2, IL-10, and IFN-𝛾 after propolis administration in the propolis-treated group before and after EHV-9 challenge compared with the control non-treated group. In conclusion, Brazilian green propolis showed no obvious effect on the prevention of acute EHV-9-induced acute encephalitis in a hamster model, despite its immune-enhancing activity.

Background. We investigated the effects of Brazilian green propolis and its constituents against white light- or UVA-induced cell damage in mouse retinal cone-cell line 661W or human skin-derived fibroblast cells (NB1-RGB). Methods. Cell damage was induced by 3,000lx white light for 24 h or 4/10 J/cm2 UVA exposure. Cell viability was assessed by Hoechst33342 and propidium iodide staining or by tetrazolium salt (WST-8) cell viability assay. The radical scavenging activity of propolis induced by UVA irradiation in NB1-RGB cells was measured using a reactive-oxygen-species- (ROS-) sensitive probe CM-H2DCFDA. Moreover, the effects of propolis on the UVA-induced activation of p38 and extracellular signal-regulated kinase (ERK) were examined by immunoblotting. Results. Treatment with propolis and two dicaffeoylquinic acids significantly inhibited the decrease in cell viability induced by white light in 661W. Propolis and its constituents inhibited the decrease in cell viability induced by UVA in NB1-RGB. Moreover, propolis suppressed the intracellular ROS production by UVA irradiation. Propolis also inhibited the levels of phosphorylated-p38 and ERK by UVA irradiation. Conclusion. Brazilian green propolis may become a major therapeutic candidate for the treatment of AMD and skin damage induced by UV irradiation.

Oxidative stress and synapse dysfunction are the major neurodegenerative damage correlated to cognitive impairment in Alzheimer's disease (AD). We have found that Brazilian green propolis (propolis) improves the cognitive functions of mild cognitive impairment patients living at high altitude; however, mechanism underlying the effects of propolis is unknown. In the present study, we investigated the effects of propolis on oxidative stress, expression of brain-derived neurotrophic factor (BDNF), and activity-regulated cytoskeleton-associated protein (Arc), the critical factors of synapse efficacy, using human neuroblastoma SH-SY5Y cells. Pretreatment with propolis significantly ameliorated the hydrogen peroxide- (H2O2-) induced cytotoxicity in SH-SY5Y cells. Furthermore, propolis significantly reduced the H2O2-generated reactive oxygen species (ROS) derived from mitochondria and 8-oxo-2′-deoxyguanosine (8-oxo-dG, the DNA oxidative damage marker) but significantly reversed the fibrillar β-amyloid and IL-1β-impaired BDNF-induced Arc expression in SH-SY5Y cells. Furthermore, propolis significantly upregulated BDNF mRNA expression in time- and dose-dependent manners. In addition, propolis induced Arc mRNA and protein expression via phosphoinositide-3 kinase (PI3K). These observations strongly suggest that propolis protects from the neurodegenerative damage in neurons through the properties of various antioxidants. The present study provides a potential molecular mechanism of Brazilian green propolis in prevention of cognitive impairment in AD as well as aging.

Propolis contains a variety of chemical compounds, including polyphenols, flavonoids, phenolic aldehydes, amino acids and vitamins, and presents numerous biological and pharmacological properties. The aim of the present study was to evaluate the effect of propolis on blood examination data in patients with type 2 diabetes. In the double-blind, 8-week randomized controlled study, 80 patients with type 2 diabetes were enrolled. Patients were randomly assigned to receive Brazilian green propolis (226.8 mg/day for 8 weeks) (n=41) or the placebo (n=39). The primary endpoint was to detect changes in blood examination data associated with metabolic disorders in patients suffering from diabetes mellitus, including the homeostasis model assessment of insulin resistance (HOMA-IR), uric acid and estimated glomerular filtration rate (eGFR) from baseline to the end of this study. The value of HOMA-IR was not significantly changed by the 8-week administration of propolis or placebo from the baseline data. Values of blood uric acid and eGFR in patients taking the placebo became worse at 8 weeks compared to the baseline, whereas this did not occur in patients consuming Brazilian green propolis. However, HOMA-IR was not improved by propolis intake. A randomized, controlled 8-week trial suggests that Brazilian green propolis (226.8 mg/day) prevents patients with type 2 diabetes from developing worse blood uric acid and eGFR.

BackgroundThe increasing incidence of cognitive impairment has become a health problem in the aging society. Owing to its antioxidant and anti-inflammatory properties, Brazilian green propolis—derived from Baccharis dracunculifolia—is anticipated to possess anticognitive properties. However, the preventive effect of Brazilian green propolis on cognitive impairment remains unexplained. This study aimed to investigate the effect of Brazilian green propolis on cognitive impairment using a mouse model of Alzheimer’s disease (AD) induced by intracerebroventricular injection of amyloid beta (Aβ)25‒35.MethodsFive-week-old male Slc:ddY mice were randomly divided into five groups (n = 8). The groups were pretreated with vehicle and propolis at a dose of 100, 300 and 900 mg/kg body weight for 8 days, then AD-like phenotypes were induced by intracerebroventricular (ICV) injection of Aβ25‒35. A sham operation group was set as the control. Memory and learning ability were measured at 7 to 8 days after ICV injection. Gene expression and histological studies were performed at the endpoint of the study.ResultsIn a passive avoidance test, the administration of Brazilian green propolis prevented the impairment of learning and memory function. Furthermore, comprehensive gene expression analysis in the hippocampus and forebrain cortex revealed that Brazilian green propolis suppressed Aβ25–35-induced inflammatory and immune responses. In particular, Brazilian green propolis prevented alterations in gene expressions of microglial and astrocytic markers such as Trem2 and Lcn2 induced by Aβ25‒35 injection, suggesting the suppression of excessive activation of glial cells in the brain. In addition, Brazilian green propolis suppressed the elevation of plasma interleukin (IL)-6 levels induced by Aβ25‒35 injection.ConclusionsThe results suggest that the prophylactic administration of Brazilian green propolis has a preventive effect against AD by suppressing excessive inflammation and immune response in glial cells. To our knowledge, this study is the first to demonstrate that Brazilian green propolis may inhibit the hyperactivation of microglia and astrocytes as a mechanism of action to prevent AD. Thus, it is a promising ingredient for preventing AD-type dementia.

Collagenase-3 (MMP-13) Enhances Remodeling of Three-Dimensional Collagen and Promotes Survival of Human Skin Fibroblasts

Atopic dermatitis (AD) is a chronic inflammatory skin disorder requiring continuous care and treatment. Therefore, exploring the therapeutic potential of natural ingredients for AD is essential. This study conducted a network analysis to investigate the anti‐AD effects of propolis and its underlying mechanism, with a focus on the compositional differences between Korean and Brazilian propolis. To identify the bioactive components and related mechanisms, differentially expressed genes (DEGs) in AD‐induced HaCaT cells with and without propolis treatment were identified. NCBI, SwissTargetPrediction, STITCH, and the Comparative Toxicogenomics Database (CTD) were used to identify target genes of the propolis compounds, and these genes were compared with the DEGs to identify the shared target genes. Notably, CXCL10 and CCL2 were highly associated with target genes shared between Korean and Brazilian propolis, with Korean propolis affecting TLR4, RIPK2, and PYCARD and Brazilian propolis influencing CEBPB, PTGS2, and DAB2IP. Korean propolis was found to predominantly impact the regulation of mast cell activation and the cytosolic DNA‐sensing pathway, whereas Brazilian propolis primarily affects Type I interferon–mediated regulation and the TNF signaling pathway. Additionally, both the TNF and IL‐17 signaling pathways were implicated in the mechanisms of both Brazilian propolis and Korean propolis. Furthermore, our study validated the therapeutic potential of propolis in AD treatment, as evidenced by significant reductions in TNF‐α, IFN‐γ, IL‐4, IL‐13, CXCL10, CCL2, and histamine release in an AD‐induced model. This study confirms the efficacy of Korean and Brazilian propolis in treating AD and reveals molecular mechanism differences due to variations in major components and target genes.

Propolis is a bee product with various biological properties, including an antiviral activity when taken orally. However, its mechanisms at the cellular and molecular level are not well understood. We investigated the effect of propolis on antiviral signaling in A549 cells transfected with double-stranded RNA (dsRNA), a model for viral infection. Pretreatment of the cells with propolis inhibited poly I:C (synthetic dsRNA)-induced interferon (IFN)-β expression. Propolis had no effect on the dsRNA-induced expression of RIG-I-like receptors (RLRs), which are known as intracellular viral RNA sensors. As to the effect on antiviral executor genes, propolis enhanced myxovirus resistance 1 (MX1) expression, whereas interferon-inducible gene 6-16 (G1P3) and 2'-5'-oligoadenylate synthetase (OAS) were unaffected. All of these genes belong to the IFN-inducible genes, suggesting that the effect of propolis on antiviral signaling is not necessarily mediated by the autocrine regulation by IFN-β. Propolis pretreatment inhibited dsRNA-induced interleukin-8 (IL8) and CCL5 expression, and consequently lowered polymorphonuclear leukocyte (PMN) chemotactic activity in the cell-conditioned medium. Taken together, these results suggest that propolis may suppress excess inflammatory responses without affecting the innate immunity during viral infection.

Effect of Brazilian green propolis on oral pathogens and human periodontal fibroblasts

Propolis contains a variety of bioactive components and possesses many biological properties. This study was designed to evaluate potential effects of Brazilian green propolis on glucose metabolism and antioxidant function in patients with type 2 diabetes mellitus (T2DM). In the 18-week randomized controlled study, enrolled patients with T2DM were randomly assigned to Brazilian green propolis group (900 mg/day) (n = 32) and control group (n = 33). At the end of the study, no significant difference was found in serum glucose, glycosylated hemoglobin, insulin, aldose reductase or adiponectin between the two groups. However, serum GSH and total polyphenols were significantly increased, and serum carbonyls and lactate dehydrogenase activity were significantly reduced in the Brazilian green propolis group. Serum TNF-α was significantly decreased, whereas serum IL-1β and IL-6 were significantly increased in the Brazilian green propolis group. It is concluded that Brazilian green propolis is effective in improving antioxidant function in T2DM patients.

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.

Aim:The study aimed to investigate whether mixing two different propolis samples can potentiate their biological activity. This hypothesis was tested by studying the effect of mixed propolis on microbial growth and wound healing and compared with the effect of each propolis individually.Materials and Methods:The effect of mixing two different propolis extracts (A and B) collected from different locations in Iraq on Escherichia coli, Staphylococcus aureus, and Candida albicans was studied by minimum inhibitory concentration assessment and compared with the effect of each propolis. Wound healing effect of the mixed propolis was studied. Twenty-four rabbits were used for the experiment, and they were assigned to four groups. Wounds were created on the dorsum of each rabbit and treated by topical application of 1 mL of either mixed propolis, propolis A, or propolis B extracts or were kept without treatment as a control. Macroscopic wound evaluation was performed with an assessment of wound size, wound recovery, redness, edema, discharge, granulation tissue, and epithelialization.Results:Propolis A was more potent than propolis B extracts to inhibit the growth of E. coli, S. aureus, and C. albicans (p<0.05). However, mixed propolis showed a higher antimicrobial activity toward all the pathogens than propolis A or propolis B extract individually (p<0.05). Furthermore, propolis A and propolis B extracts showed favorable effects on wound healing which was more pronounced with propolis A extract. Interestingly, mixed propolis accelerated wound healing faster than propolis A or propolis B extracts, and it shortened the time of reepithelialization (p<0.05).Conclusion:This study demonstrates for the first time that mixing different propolis samples possesses a higher antimicrobial activity and higher wound healing property than individual propolis. This approach could pave the way for the development of more effective antimicrobials and wound healing agents.

Recent in vitro studies suggest that propolis and some of its phenolic components are able to inhibit Helicobacter pylori growth. To date, there are no clinical studies. To evaluate the effect of Brazilian green propolis on H. pylori-infected individuals. Eighteen (11 females, 7 males, mean age 47 years) participants were included. Before treatment, all participants were submitted to gastroscopy, and H. pylori infection was confirmed by histology, urease test, and (13)C-urea breath test (UBT). Participants with UBT showing a delta over baseline (DOB) value higher than 4 per thousand were considered positive for H. pylori infection. Twenty drops from an alcoholic preparation of Brazilian green propolis were administered three times a day for 7 days. Clinical evaluation and UBT were performed at 1-3 days and at 40 days after the end of therapy to evaluate H. pylori suppression or eradication, respectively. All participants took all medication and completed the study. Eighty-three percent of the subjects did not succeed in suppressing or eradicating H. pylori. Two participants reached partial suppression after treatment, but became positive again at UBT performed 40 days after treatment. Another participant presented negative at UBT 40 days after treatment, not confirmed by a second UBT performed 100 days after treatment. Brazilian green propolis used in popular dose showed minimal effect on H. pylori infection. Larger studies with longer duration, larger dose, and different frequency of administration of propolis extract should be undertaken to define its role on H. pylori therapy.

This study evaluated the antiproliferative activity of the Brazilian green propolis and Baccharis dracunculifolia extracts and their major compounds artepillin C and baccharin in different tumor cell lines. The lowest IC50 values observed for Brazilian green propolis and B. dracunculifolia extracts were 41.0 ± 4.5 µg/mL for U343 and 44.9 ± 7.1 µg/mL for HepG2, respectively. Regarding artepillin C and baccharin, the lowest IC50 values were 20.1 ± 2.9 for U343 and 13.0 ± 1.5 µg/mL for B16F10, respectively. For the association of artepillin C plus baccharin, the lowest IC50 result was 35.2 ± 0.5 µg/mL for B16F10. Artepillin C and baccharin were more cytotoxic than both Brazilian green propolis and B. dracunculifolia extracts. No additive or synergistic effect was observed for the association of artepillin C plus baccharin.

Propolis has been suggested as a storage medium for avulsed teeth. The aim of this study was to compare the effectiveness of Brazilian propolis with Hank's balanced salt solution and milk in maintaining the viability of human periodontal ligament cells, their osteogenic differentiation potential, and pro-inflammatory cytokine expression. Cell Counting Kit 8 assays were performed to test human periodontal ligament cell viability in different storage media. The preservative effect on osteogenic differentiation was evaluated using alkaline phosphatase staining and activity assays, Alizarin Red S staining, and western blotting. Quantification of pro-inflammatory cytokines was performed using real-time PCR and enzyme-linked immunosorbent assays. Brazilian propolis at 10 μg/ml was not cytotoxic toward human periodontal ligament cells. The milk group showed the highest cell viability. Brazilian propolis and Hank's balanced salt solution groups showed similar cell viabilities. Alkaline phosphatase staining and activity were similar in all groups. Calcium deposition and mineralization nodule formation were similar in the Brazilian propolis and Hank's balanced salt solution groups, but were higher in the milk group. Osteogenic marker gene and protein levels were similar in all groups. The genes and protein expression levels of IL1β, IL6, and IL8 decreased significantly after treatment with Brazilian propolis. TNFα mRNA expression showed no significant difference among the experimental groups. Pro-inflammatory cytokine levels in the milk group were higher than in the Brazilian propolis and Hank's balanced salt solution groups. Brazilian propolis, Hank's balanced salt solution, and milk maintained the viability of human periodontal ligament cells and preserved their osteogenic differentiation ability similarly. However, Brazilian propolis showed a better anti-inflammatory effect. This article is protected by copyright. All rights reserved.