Perspectives for Uses of Propolis in Therapy against Infectious Diseases

Brazilian red propolis synergistically with imipenem modulates immunological parameters and the bactericidal activity of human monocytes against methicillin-resistant Staphylococcus aureus (MRSA)

OBJECTIVES

Propolis is a bee product found all over the globe and has a well-known antibacterial activity. Previous findings of our group revealed that the combination of Brazilian red propolis (BRP) with a lower concentration of imipenem (IPM) exerted a bactericidal action against methicillin-resistant Staphylococcus aureus (MRSA) in vitro. Here, we aimed at investigating the effects of BRP in combination or not with IPM on human monocytes to assess a possible immunomodulatory action.

METHODS

Monocyte metabolic activity was analysed by MTT assay, cytokine production (TNF-α, IL-1β, IL-6, IL-8, and IL-10) by ELISA, and the expression of cell markers (TLR-2, TLR-4, HLA-DR, and CD80) by flow cytometry. The bactericidal activity of monocytes over MRSA was determined by colony-forming units' count.

KEY FINDINGS

BRP alone or in combination with IPM exerted no cytotoxic effects on monocytes. BRP downregulated TLR-2 expression and inhibited TNF-α, IL-1β, and IL-6 production, while BRP + IPM stimulated these parameters. BPR alone or in combination increased the bactericidal activity similarly to LPS-activated monocytes.

CONCLUSIONS

Data indicated the potential of BRP as an anti-inflammatory agent increasing the bactericidal activity of monocytes against MRSA. The combination of BRP + IPM exhibited a stimulatory profile that may be potentially useful in treating patients with MRSA infection.

Forecasting the Impact of Climate Change on Apis dorsata (Fabricius, 1793) Habitat and Distribution in Pakistan

Climate change has led to global biodiversity loss, severely impacting all species, including essential pollinators like bees, which are highly sensitive to environmental changes. Like other bee species, A. dorsata is also not immune to climate change. This study evaluated the habitat suitability of A. dorsata under climate change in Pakistan by utilizing two years of occurrence and distribution data to develop a Maximum Entropy (MaxEnt) model for forecasting current and future habitat distribution. Future habitat projections for 2050 and 2070 were based on two shared socioeconomic pathways (SSP245 and SSP585) using the CNRM-CM6-1 and EPI-ESM1-2-HR-1 global circulation models. Eight bioclimatic variables (Bio1, Bio4, Bio5, Bio8, Bio10, Bio12, Bio18, and Bio19) were selected for modeling, and among the selected variables, the mean temperature of the wettest quarter (Bio8) and precipitation of the warmest quarter (Bio18) showed major contributions to the model building and strongest influence on habitat of A. dorsata. The model estimated 23% of our study area as a suitable habitat for A. dorsata under current climatic conditions, comprising 150,975 km2 of moderately suitable and 49,792 km2 of highly suitable regions. For future climatic scenarios, our model projected significant habitat loss for A. dorsata with a shrinkage and shift towards northern, higher-altitude regions, particularly in Khyber Pakhtunkhwa and the Himalayan foothills. Habitat projections under the extreme climatic scenario (SSP585) are particularly alarming, indicating a substantial loss of the suitable habitat for the A. dorsata of 40% under CNRM-CM6-1 and 79% for EPI-ESM1-2-HR-1 for the 2070 time period. This study emphasizes the critical need for conservation efforts to protect A. dorsata and highlights the species' role in pollination and supporting the apiculture industry in Pakistan.

Antioxidant Activity, Phenolic Acid, and Flavonoid Composition of an Antiseptic Ointment Based on Aloe and Green Propolis and Its Potential for Preventing Mastitis in Dairy Cows

Mastitis is a major challenge in dairy production, leading to decreased milk yield and quality due to increased somatic cell counts (SCCs). The overuse of antibiotics to treat this condition has raised concerns about antimicrobial resistance, prompting the search for alternative treatments. This study aimed to evaluate the antioxidant activity, phenolic acid, and flavonoid content of a natural antiseptic ointment based on green propolis and aloe vera. The phenolic and flavonoid composition was determined using ultra-high-performance liquid chromatography, revealing high concentrations of bioactive compounds, particularly in the green propolis extract. The antioxidant activity was assessed using the DPPH method, and the ointment was applied as a post-dipping treatment in dairy cows. Over a 56-day period, the SCC in cows treated with the ointment showed a significant reduction (p = 0.021) compared to the control group (1.94 and 2.21 log10 SCC/mL, respectively). These findings indicate that the combination of green propolis and aloe vera possesses promising antimicrobial and healing properties, making it an effective alternative for mastitis prevention in dairy cows.

Effects of propolis extract supplementation in breeder and broiler diets and it's in ovo injection on immune status, blood parameters, vaccine-antibody response and intestinal microflora of broiler chick

This study evaluated the effects of dietary propolis extract supplementation and in-ovo propolis injection on the immune status, blood parameters, vaccine-antibody response, and intestinal microflora of broiler chickens. A total of 600 Ross 308 broiler chicks were used. Breeder diets were supplemented with 400 ppm propolis extract (P) or left unsupplemented (C) during weeks 38-39. Eggs from the control group (C) were divided into four groups, with in-ovo injections of 400 ppm propolis extract (C-iP) or physiological saline (C-iS) on day 18 of incubation. Untreated eggs formed the control (C-C) or propolis-supplemented (P-C) groups. Chicks were fed either a basal diet (C) or a diet supplemented with 400 ppm propolis extract (P), forming six experimental groups: C-C, C-P, P-C, P-P, C-iP, and C-iS, with 10 replicates per group (10 chicks per replicate). Propolis supplementation significantly increased immunoglobulin levels (IgA, IgG, IgM) compared to the control group. Although it positively affected certain blood parameters, no significant differences were found in post-vaccination antibody titers. The C-C group had the highest total antioxidant levels, while total oxidant levels and oxidative stress index were lowest in the P-P group. Despite positive effects on blood parameters and intestinal microflora, no significant improvements in growth performance were observed. Nevertheless, propolis extract shows potential as an immune enhancer for broiler chickens through parental feeding, standard diets, or in-ovo injection.

The Clinical Effectiveness of Propolis on the Endodontic Treatment of Permanent Teeth: A Systematic Review of Randomized Clinical Trials and Updates

Endodontic treatment of permanent teeth (immature and mature) with propolis in healthy patients remains uncertain, with conflicting evidence. Therefore, this systematic review aims to evaluate the current literature on the safety and efficacy of propolis in endodontic procedures. An extensive literature search was performed using PubMed, Scopus, Web of Sciences, and Google Scholar. Only human randomized clinical trials (RCTs) that explored the clinical applications of propolis in endodontics were considered. Narrative synthesis was performed, and the risk of bias (RoB) for methodological quality assessment was performed with the Cochrane RoB-2 via the Robvis web-based application. Eight RCTs were selected, focusing on using propolis in vital pulps for direct pulp capping and non-vital pulps for root canal disinfection and filling materials. Propolis demonstrated promising effects, including controlling inflammation, promoting tissue healing, and disinfecting the root canal system. However, no significant differences were observed when comparing propolis to other materials used in pulp capping or intracanal medicaments. The RoB assessment revealed varied levels of risk, with two studies exhibiting a high risk, three having unclear risks, and three showing low risk. Moderate certainty of evidence was observed. Based on the current evidence, there is insufficient data to recommend propolis over other materials in the treatment of vital or non-vital pulps in permanent teeth. Propolis was not recommended as a definitive treatment due to the limited evidence and variability in the clinical outcomes across studies. However, future high-quality RCTs are essential for more definitive conclusions.

Assessing multi-target antiviral and antioxidant activities of natural compounds against SARS-CoV-2: an integrated in vitro and in silico study

There is an urgent need for preventive and therapeutic drugs to effectively treat and prevent viral diseases from resurfacing as they emerge during the COVID-19 pandemic. This study aims to assess the antiviral effects of four natural compounds commonly used in traditional medicine to treat SARS-CoV-2 infection. A cytotoxicity, dose-dependent, and plaque reduction assay was performed on Vero CCL-81 cells to figure out their effects on the cells. Quantification of cytokines was assessed. In silico analysis for the selected compound was also evaluated. Results revealed that the compounds could disrupt the viral replication cycle through direct inhibition of the virus or immune system stimulation. The cytotoxicity assay results revealed that the compounds were well tolerated by the cells, indicating that the compounds were not toxic to the cells. This study evaluated the antioxidant capacities of propolis, curcumin, quercetin, and ginseng using ABTS, FRAP, and CUPRAC assays, revealing that propolis exhibited the highest antioxidant activity of ABTS with 1250.40 ± 17.10 μmol Trolox eq/g, with FRAP values reaching 1200.55 ± 15.90 μmol Fe2⁺ eq/g and CUPRAC values of 1150.80 ± 14.20 μmol Trolox eq/g at 1000 µg/mL, highlighting its potential as a potent natural antioxidant. The results of the plaque reduction assay revealed that the compounds could reduce the size and number of plaques, indicating that the compounds could inhibit the virus replication cycle. Subsequently, using molecular docking to analyze the effect of propolis, curcumin, quercetin, and ginseng as inhibitors, it was unveiled that the four compounds are likely to have the potential to inhibit the protease activity, spike protein S1, and RNA polymerase of SARS-CoV-2 and the virus titer was reduced by 100% after post-infection using propolis as an inhibitor control.

Propolis in Dental Implantology: A Systematic Review of Its Effects and Benefits

Dental implants are widely recognized for their effectiveness in restoring missing teeth, yet their success is often compromised by infections or inadequate osseointegration. Propolis, a natural resinous substance with potent antimicrobial, anti-inflammatory, and osteogenic properties, has emerged as a promising adjunct in dental implantology. This systematic review critically evaluates the current evidence on the incorporation of propolis into dental implants, focusing on its impact on antimicrobial efficacy, bone healing, and overall implant stability. The study protocol was registered in PROSPERO under the registration number CRD42024577122. The PRISMA diagram visually represented the search strategy, screening, and inclusion process. Two reviewers conducted a comprehensive literature search across five databases: PubMed, PubMed Central, Embase, Scopus, and Web of Science. The review synthesized findings from 13 studies; in vitro, in vivo, and clinical studies, highlighting that propolis significantly enhances antibacterial and antifungal activities against pathogens such as Staphylococcus aureus, Candida albicans, and Streptococcus mutans, thereby reducing the risk of peri-implant infections. Additionally, propolis promotes osseointegration by stimulating osteoblast activity and reducing inflammatory cytokine expression, leading to improved bone formation and implant stability. The anti-inflammatory and antioxidant properties of propolis further contribute to a favorable healing environment, enhancing the long-term success of dental implants. The systematic review underscores the potential of propolis as a safe, biocompatible, and effective material for improving dental implant outcomes. However, it also identifies the need for more extensive clinical trials to fully establish standardized protocols for propolis application in implantology. This review provides an overview of propolis's potential role in dental implants and suggests promising avenues for future research to optimize its benefits in clinical practice.

Development of a Benzophenone-Free Red Propolis Extract and Evaluation of Its Efficacy against Colon Carcinogenesis

BACKGROUND/OBJECTIVES

Brazilian red propolis has attracted attention for its pharmacological properties. However, signs of toxicity were recently observed in long-term studies using the hydroalcoholic extract of red propolis (RPHE), likely due to polyprenylated benzophenones. This study aimed to develop a benzophenone-free red propolis extract (BFRP) and validate an HPLC-PDA method to quantify its main constituents: isoliquiritigenin, vestitol, neovestitol, medicarpine, and 7-O-methylvestitol.

METHODS

BFRP's toxicity was assessed in zebrafish larvae through a vibrational startle response assay (VSRA) and morphological analysis. Genotoxicity was evaluated using the micronucleus test in rodents, and the extract's effects on chemically induced preneoplastic lesions in rat colon were studied. An HPLC-PDA method was used to quantify BFRP's main compounds.

RESULTS

BFRP primarily contained vestitol (128.24 ± 1.01 μg/mL) along with isoliquiritigenin, medicarpin, neovestitol, and 7-O-methylvestitol. Zebrafish larvae exposed to 40 µg/mL of BFRP exhibited toxicity, higher than the 10 µg/mL for RPHE, though no morphological differences were found. Fluorescent staining in the notochord, branchial arches, and mouth was observed in larvae treated with both BFRP and RPHE. No genotoxic or cytotoxic effects were observed up to 2000 mg/kg in rodents, with no impact on hepatotoxicity or nephrotoxicity markers. Chemoprevention studies showed a 41.6% reduction in preneoplastic lesions in rats treated with 6 mg/kg of BFRP.

CONCLUSIONS

These findings indicate that BFRP is a safe, effective propolis-based extract with potential applications for human health, demonstrating reduced toxicity and chemopreventive properties.

Endodontic Applications of Propolis in Primary and Permanent Teeth: A Scoping Review of Clinical Studies

OBJECTIVE

The use of propolis-based materials within endodontics to promote pulp wound healing or disinfect the root canal system has been a recent focus of scientists and clinicians. This is mainly because of the well-documented antimicrobial, anti-inflammatory, immunomodulatory and wound healing properties of propolis. This scoping review critically appraises the literature on the clinical applications of propolis-based compounds during endodontic therapy of primary and permanent teeth.

METHODS

An electronic literature search was performed in Scopus, PubMed, and Web of Science up to and including October 2023 to identify studies assessing the use of propolis during endodontic therapy of primary and permanent teeth. A combination of relevant MeSh terms and keywords was used. Only human clinical studies written in English were included. The identified manuscripts were screened and assessed for inclusion by two independent authors. Eligible manuscripts were then subjected to critical appraisal and data extraction with the information being summarised according to their clinical application.

RESULTS

A total of 26 human clinical studies were identified and included in the analysis. Propolis was investigated for use in the primary and permanent dentitions as a direct pulp capping or pulpotomy material as well as in root canal disinfection and root filling of teeth with non-vital pulps. Overall, the studies reported that the use of propolis was associated with promising outcomes in terms of efficacy to control inflammation, enhance tissue repair, and disinfection of the root canal system. However, a critical appraisal of the studies revealed a range of methodological and reporting deficiencies, resulting in unreliable results and conclusions in terms of the clinical outcomes reported.

CONCLUSION

Although the studies on the use of propolis-based materials in endodontics reported promising clinical outcomes, they had a range of methodological and reporting flaws. Further well-designed and properly reported controlled clinical studies are essential to derive sound evidence-based conclusions on propolis-based materials. Furthermore, guidelines for quality assurance and safe use of propolis-based materials are necessary to enhance their production for commercial use in endodontics.

In Vitro Antimicrobial Potential of Portuguese Propolis Extracts from Gerês against Pathogenic Microorganisms

Antimicrobial resistance (AMR) is one of humanity's main health problems today. Despite all the breakthroughs and research over the past few years, the number of microbial illnesses that are resistant to the available antibiotics is increasing at an alarming rate. In this article, we estimated the biomedical potential of Portuguese propolis harvested from the Gerês apiary over five years, evaluating the in vitro antimicrobial effect of five hydroalcoholic extracts prepared from five single propolis samples and of a hydroalcoholic extract obtained from the mixture of all samples. The antimicrobial potential was firstly assessed by determining the minimum inhibitory concentration (MIC) of these extracts against a panel of three Gram-positive (Bacillus subtilis, methicillin-sensitive Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus) and one Gram-negative bacteria (Escherichia coli), as well as two yeasts (Candida albicans and Saccharomyces cerevisiae). As MIC values against each bacterium were consistent across all the evaluated propolis extracts, we decided to further conduct a disk diffusion assay, which included three commercial antibiotics-erythromycin, vancomycin, and amoxicillin/clavulanic acid-for comparison purposes. In addition to displaying a concentration-dependent antibacterial effect, the hydroalcoholic extracts prepared with 70% ethanol exhibited stronger antimicrobial capacity than vancomycin against B. subtilis (% of increase ranged between 26 and 59%) and methicillin-sensitive S. aureus (% of increase ranged between 63 and 77%). Moreover, methicillin-resistant S. aureus (MRSA) showed susceptibility to the activity of the same extracts and resistance to all tested antibiotics. These findings support that propolis from Gerês is a promising natural product with promising antimicrobial activity, representing a very stimulating result considering the actual problem with AMR.

bibliometric analysis of the top 100 most-cited articles concerning the use of propolis in dentistry

Aim: The objective of this bibliometric analysis was to identify and analyze the key characteristics of the 100 most-cited articles related to the use of propolis in dentistry. Methods: The search was conducted in the Web of Science Core Collection, and two independent reviewers selected the articles, excluding meeting articles. The number of citations for each article was compared across the Scopus and Google Scholar databases. The extracted data included the number and density of citations, year of publication, journal and impact factor, study design and theme, country and continent, institution, keywords, and authors. VOSviewer software was employed to generate collaborative network maps. Spearman correlation and Poisson regression analyses were performed on the data. Results: The number of citations ranged from 26 to 247, with a citation density varying between 1.08 and 20.00. Articles were published between 1991 and 2021, with laboratory studies (70%) and antimicrobial activity (39%) being the most prevalent study design and theme, respectively. The most discussed dental specialty was microbiology (49%). Rosalen PL (27%) emerged as the author with the highest number of articles, and the University of Campinas (Brazil) was the most prolific institution. Poisson regression indicated a declining trend in citations over the years, though literature reviews exhibited higher citation performance. Brazil contributed the highest percentage of articles (41%). Conclusion: In conclusion, the 100 most-cited articles predominantly comprised laboratory studies investigating the antimicrobial activity of propolis, primarily originating from Brazil, with notable emphasis on the University of Campinas.

Oral Films Printed with Green Propolis Ethanolic Extract

Oral film (OF) research has intensified due to the effortless administration and advantages related to absorption in systemic circulation. Chitosan is one of the polymers widely used in the production of OFs; however, studies evaluating the maintenance of the active principles' activity are incipient. Propolis has been widely used as an active compound due to its different actions. Printing techniques to incorporate propolis in OFs prove to be efficient. The objective of the present study is to develop and characterize oral films based on chitosan and propolis using printing techniques and to evaluate the main activities of the extract incorporated into the polymeric matrix. The OFs were characterized in relation to the structure using scanning and atomic force electron microscopy; the mechanical properties, disintegration time, wettability, and stability of antioxidant activity were evaluated. The ethanolic extract of green propolis (GPEE) concentration influenced the properties of the OFs. The stability (phenolic compounds and antioxidant activity) was reduced in the first 20 days, and after this period, it remained constant.

Antibacterial Effects of Various Types of Bee Products in Malaysia: A Systematic Review

Antibiotics are widely used to treat bacterial infections. The effectiveness of antibiotics is very important, but unfortunately, prolonged exposure leads to the development of antibiotic resistance in some bacteria. Hence, using natural products as antibacterial agents is an attractive alternative, given that they have been used as traditional medicine since the existence of humanity. This study systematically reviewed the antibacterial activity of Malaysian bee products such as honey, propolis and bee bread. Five electronic databases: i) PubMed; ii) ScienceDirect; iii) Scopus; iv) Web of Science Core Collection and v) Google Scholar, were searched for relevant articles. A total of 153 articles were obtained from the initial search. Of these, 32 articles, including 24 on honey, eight on propolis and one on bee bread, were selected based on inclusion and exclusion criteria. Most studies reported that honey, propolis and bee bread demonstrated antibacterial properties against Gram-positive and Gram-negative bacteria.

Effect of propolis mouthwash on the incidence of ventilator-associated pneumonia in intensive care unit patients: a comparative randomized triple-blind clinical trial

OBJECTIVES

Ventilator-associated pneumonia (VAP) increases the length of hospitalization and mortality rate. This study aimed to determine the effect of propolis mouthwash on the incidence of VAP in intensive care unit (ICU) patients.

MATERIALS AND METHODS

Triple-blind, comparative randomized, controlled clinical trial was conducted over one year, with 110 ICU patients at Imam-Hossein and Bahar hospitals (Shahroud) and Kowsar Hospital (Semnan) in Iran. The intervention group used 15 cc of 0.06% propolis mouthwash solution twice daily at 8 AM and 4 PM for seven days. The control group used 15 cc of 0.2% chlorhexidine mouthwash at the same times and duration. Data were collected using a demographic questionnaire, APACHE II, Beck Oral Assessment Scale, and Modified Clinical Pulmonary Infection Score (MCPIS).

RESULTS

There was no significant difference in demographic information, disease severity, and oral health between the two groups before and after intervention (P > 0.05). The incidence of VAP in the intervention group compared to the control group was 10.9% vs. 30.9% on the third day (P = 0.0166, 95% CI: 0.53-0.83 and RR = 0.35), 23.6% vs. 43.6% on the fifth day (P = 0.0325 and 95% CI: 0.31-0.95 and RR = 0.54), and 25.5% vs. 47.3% on the seventh day (P = 0.0224, 95% CI: 0.32-0.92, and RR = 0.54). The Mann-Whitney indicated the incidence of VAP was significantly lower in the intervention group on the third, fifth, and seventh days.

CONCLUSION

Propolis mouthwash can be considered as an alternative to chlorhexidine mouthwash for ICU patients.

CLINICAL RELEVANCE

Propolis mouthwash serves as a simple, economical intervention to potentially reduce incidence of VAP.

TRIAL REGISTRATION

(IRCT20110427006318N12, date 02.04.2019).

In vitro and in vivo burn healing study of standardized propolis: Unveiling its antibacterial, antioxidant and anti-inflammatory actions in relation to its phytochemical profiling

BACKGROUND

Natural propolis has been used since decades owing to its broad-spectrum activities. Burn injuries are a global health problem with negative impacts on communities. Bacterial infections usually accompany burns, which demand implementation of antibiotics. Antibiotics abuse led to emergence of microbial drug resistance resulting in poor treatment outcomes. In such instances, the promising alternative would be natural antimicrobials such as propolis.

OBJECTIVE

Full chemical profiling of propolis and evaluation of in vitro antibacterial, antioxidant and anti-inflammatory activities as well as in vivo burn healing properties.

METHODS

Chemical profiling of propolis was performed using Liquid chromatography (UHPLC/MS-PDA and HPLC-PDA). In vitro assessment was done using Disc Diffusion susceptibility test against Staphylococcus aureus and infected burn wound mice model was used for in vivo assessment. In vitro antioxidant properties of propolis were assessed using DPPH, ABTS and FRAP techniques. The anti-inflammatory effect of propolis was assessed against lipopolysaccharide/interferon-gamma mediated inflammation.

RESULTS

UHPLC/MS-PDA results revealed identification of 71 phytochemicals, mainly flavonoids. Upon flavonoids quantification (HPLC-PDA), Pinocembrin, chrysin and galangin recorded high content 21.58±0.84, 22.73±0.68 and 14.26±0.70 mg/g hydroalcoholic propolis extract, respectively. Propolis showed concentration dependent antibacterial activity in vitro and in vivo burn healing via wound diameter reduction and histopathological analysis without signs of skin irritation in rabbits nor sensitization in guinea pigs. Propolis showed promising antioxidant IC50 values 46.52±1.25 and 11.74±0.26 μg/mL whereas FRAP result was 445.29±29.9 μM TE/mg. Anti-inflammatory experiment results showed significant increase of Toll-like receptor 4 (TLR4), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) mRNA levels. Nitric oxide and iNOS were markedly increased in Griess assay and western blot respectively. However, upon testing propolis against LPS/IFN-γ-mediated inflammation, TLR4, IL-6 and TNF-α expression were downregulated at transcriptional and post-transcriptional levels.

CONCLUSION

Propolis proved to be a promising natural burn healing agent through its antibacterial, antioxidant and anti-inflammatory activities.

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.

Effects of caatinga propolis from Mimosa tenuiflora and its constituents (santin, sakuranetin and kaempferide) on human immune cells

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis is a bee product used in folk medicine to treat inflammatory diseases. Diverse types of propolis are produced worldwide depending on the local flora. Recently, research has been focused on a propolis sample produced in the northeast Brazilian "caatinga" from Mimosa tenuiflora, popularly known as "jurema-preta".

AIM OF THE STUDY

A possible immunomodulatory/anti-inflammatory action was analyzed to verify the potential of M. tenuiflora propolis (MP) and its constituents (santin, sakuranetin and kaempferide) in human immune cells under baseline conditions or in LPS-stimulated cells.

METHODS

Cell viability, cytokine (TNF-α, IL-1β, IL-6, IL-8, IL-10) production and intracellular pathways (NF-kB and p38 MAPK) were evaluated.

RESULTS

Under basal conditions, MP and sakuranetin did not affect cytokine production; santin enhanced TNF-α, IL-1β, IL-6, while kaempferide inhibited IL-8 and IL-10. In LPS-stimulated cells, MP and its compounds exerted an inhibitory activity on TNF-α and IL-1β, while no effects were seen on IL-6 and IL-8. Santin and kaempferide inhibited IL-10 production. No significant differences were seen on NF-kB and p38 MAPK intracellular pathways.

CONCLUSION

Data indicated the immunomodulatory action of caatinga propolis and its constituents at noncytotoxic concentrations, specifically an anti-inflammatory activity in LPS-treated cells by inhibiting cytokine production. Santin, sakuranetin and kaempferide appeared to be involved in MP activities.

Mechanistic role of quercetin as inhibitor for adenosine deaminase enzyme in rheumatoid arthritis: systematic review

Rheumatoid arthritis (RA) is an autoimmune disease involving T and B lymphocytes. Autoantibodies contribute to joint deterioration and worsening symptoms. Adenosine deaminase (ADA), an enzyme in purine metabolism, influences adenosine levels and joint inflammation. Inhibiting ADA could impact RA progression. Intracellular ATP breakdown generates adenosine, which increases in hypoxic and inflammatory conditions. Lymphocytes with ADA play a role in RA. Inhibiting lymphocytic ADA activity has an immune-regulatory effect. Synovial fluid levels of ADA are closely associated with the disease's systemic activity, making it a useful parameter for evaluating joint inflammation. Flavonoids, such as quercetin (QUE), are natural substances that can inhibit ADA activity. QUE demonstrates immune-regulatory effects and restores T-cell homeostasis, making it a promising candidate for RA therapy. In this review, we will explore the impact of QUE in suppressing ADA and reducing produced the inflammation in RA, including preclinical investigations and clinical trials.

In vitro antiviral effect of Mexican and Brazilian propolis and phenolic compounds against human coronavirus 229E

Propolis is a resinous substance collected by bees (Apis mellifera). It is used for its biological properties. This natural product is available as a safe therapeutic option. Herein, we report the antiviral effects of brown propolis extract from Mexico and green and red propolis extracts from Brazil, as well as their phenolic compounds (quercetin, caffeic acid, and rutin) in preventing infection of MRC-5 cells by HCoV-229E. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. All samples studied showed antiviral activity. Green and brown propolis extracts, and quercetin exhibited the best EC50 values with values of 19.080, 11.240, and 77.208 µg/mL against HCoV-229E, respectively, and with TC50 of 62.19, 29.192, and 298 µg/mL on MRC-5 cells, respectively. These results are the first in vitro study of the effects of propolis on HCoV-229E and provide the basis for the development of natural formulations against other coronavirus strains.

Exploring the Functional Properties of Propolis, Geopropolis, and Cerumen, with a Special Emphasis on Their Antimicrobial Effects

Bee propolis has been touted as a natural antimicrobial agent with the potential to replace antibiotics. Numerous reports and reviews have highlighted the functionalities and applications of the natural compound. Despite much clamor for the downstream application of propolis, there remain many grounds to cover, especially in the upstream production, and factors affecting the quality of the propolis. Moreover, geopropolis and cerumen, akin to propolis, hold promise for diverse human applications, yet their benefits and intricate manufacturing processes remain subjects of intensive research. Specialized cement bees are pivotal in gathering and transporting plant resins from suitable sources to their nests. Contrary to common belief, these resins are directly applied within the hive, smoothed out by cement bees, and blended with beeswax and trace components to create raw propolis. Beekeepers subsequently harvest and perform the extraction of the raw propolis to form the final propolis extract that is sold on the market. As a result of the production process, intrinsic and extrinsic factors, such as botanical origins, bee species, and the extraction process, have a direct impact on the quality of the final propolis extract. Towards the end of this paper, a section is dedicated to highlighting the antimicrobial potency of propolis extract.

Ethanolic Extract of Propolis Modulates Autophagy-Related microRNAs in Osteoarthritic Chondrocytes

Osteoarthritis is a multifactorial joint disease characterized by degeneration, and aging stands as a significant risk factor. Autophagy, a crucial cellular homeostasis mechanism, is influenced by aging and closely linked to cartilage health. This correlation between autophagy, cell death, and OA underscores its relevance in disease progression. MicroRNAs have emerged as autophagy regulators, with miRNA-based interventions showing promise in preclinical models. Remarkably, the ethanolic extract of propolis exhibits positive effects on autophagy-related proteins and healthy cartilage markers in an in vitro osteoarthritis model. The aim of this brief report was to evaluate through in silico analysis and postulate five microRNAs that could regulate autophagy proteins (AKT1, ATG5, and LC3) and assess whether the ethanolic extract of propolis could regulate the expression of these microRNAs. Among the examined miRNAs (miR-19a, miR-125b, miR-181a, miR-185, and miR-335), the ethanolic extract of propolis induced significant changes in four of them. Specifically, miR-125b responded to EEP by counteracting IL-1β-induced effects, while miR-181a, miR-185, and miR-335 exhibited distinct patterns of expression under EEP treatment. These findings unveil a potential link between miRNAs, EEP, and autophagy modulation in OA, offering promising therapeutic insights. Nevertheless, further validation and clinical translation are warranted to substantiate these promising observations.

Anti-MRSA and Biological Activities of Propolis Concentrations Loaded to Chitosan Nanoemulsion for Pharmaceutics Applications

Propolis is a naturally occurring substance with beneficial properties; bees produce it from various plant sources, and it is an anti-inflammatory and therapeutic resinous substance. This study aimed to enhance the biological features of propolis extract by loading it onto active film. Firstly, extraction was performed using three solvent systems, and their total phenolic, flavonoid, and antioxidant activity was measured. Propolis ethanol extract (EEP) was evaluated for phenolic fraction content and then chosen to prepare a chitosan-loaded emulsion with several concentrations. The antibacterial, anti-mycotic, and anti-mycotoxigenic properties of the extract and nanoemulsion were assessed. PPE's cytotoxicity and nanoemulsion were evaluated using brine shrimp and cell line assays. Results indicate higher phenolic (322.57 ± 4.28 mg GAE/g DW), flavonoid (257.64 ± 5.27 mg QE/g DW), and antioxidant activity of the EEP. The phenolic fraction is distinguished by 18 phenolic acids with high p-hydroxybenzoic content (171.75 ± 1.64 µg/g) and 12 flavonoid compounds with high pinocembrin and quercetin content (695.91 ± 1.76 and 532.35 ± 1.88 µg/g, respectively). Phenolic acid derivatives (3,4-Dihydroxybenzaldehyde, 3,4-Dihydroxyphenol acetate, and di-methoxy cinnamic) are also found. Concentrations of 50, 100, 150, and 200 ng EEP loaded on chitosan nanoemulsion reflect significant antibacterial activity against pathogenic bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA) and toxigenic fungi, particularly Fusarium. Among the four EEP-loaded concentrations, the nanoemulsion with 150 ng showed outstanding features. Using a simulated medium, 150 and 200 ng of EEP-loaded chitosan nanoemulsion concentrations can stop zearalenone production in Fusarium media with complete fungi inhibition. Also, it reduced aflatoxins production in Aspergillus media, with fungal inhibition (up to 47.18%). These results recommended the EEP-chitosan application for pharmaceutics and medical use as a comprehensive wound healing agent.

Therapeutic efficacy of caffeic acid phenethyl ester in cancer therapy: An updated review

Nowadays, there is a lot of public and scientific interest in using phytochemicals to treat human ailments. Existing cancer medicines still run across obstacles, despite significant advancements in the field. For instance, chemotherapy may result in severe adverse effects, increased drug resistance, and treatment failure. Natural substances that are phytochemically derived provide innovative approaches as potent therapeutic molecules for the treatment of cancer. Bioactive natural compounds may enhance chemotherapy for cancer by increasing the sensitivity of cancer cells to medicines. Propolis has been found to interfere with the viability of cancer cells, among other phytochemicals. Of all the components that make up propolis, caffeic acid phenethyl ester (CAPE) (a flavonoid) has been the subject of the most research. It demonstrates a broad spectrum of therapeutic uses, including antitumor, antimicrobial, antiviral, anti-inflammatory, immunomodulatory, hepatoprotective, neuroprotective, and cardioprotective effects. Studies conducted in vitro and in vivo have demonstrated that CAPE specifically targets genes involved in cell death, cell cycle regulation, angiogenesis, and metastasis. By altering specific signaling cascades, such as the NF-κB signaling pathway, CAPE can limit the proliferation of human cancer cells. This review highlights the research findings demonstrating the anticancer potential of CAPE with a focus on multitargeted molecular and biological implications in various cancer models.

Chewable tablet with herbal extracts and propolis arrests Wuhan and Omicron variants of SARS-CoV-2 virus

Prevention of COVID-19 is of paramount importance for public health. Some natural extracts might have the potential to suppress COVID-19 infection. Therefore, this study aimed to design a standardised, efficient, and safe chewable tablet formulation (with propolis and three herbal extracts) for possible prevention against two variants (Wuhan B.1.36 and Omicron BA.1.1) of SARS-CoV-2 virus and other viral infections. Green tea, bilberry, dried pomegranate peel, and propolis extracts were selected for this purpose. Cytotoxicity and antiviral activity of each component, as well as the developed chewable tablet, were examined against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus using Vero E6 cells with the xCELLigence real-time cell analyser-multiple plates system. Anti-inflammatory and analgesic activities, as well as mutagenicity and anti-mutagenicity of the chewable tablet were also analysed. Compared to the control, it was observed that the chewable tablet at concentrations of 110 and 55 µg/mL had antiviral activity rates of 101% and 81%, respectively, for the Wuhan variant and 112% and 35%, respectively, for the Omicron variant. The combination of herbal extracts with propolis extract were synergically more effective (∼7-fold higher) than that of individual extract. The present work suggests that a combination of herbal extracts with propolis at suitable concentrations can effectively be used as a food supplement for the prevention of both variants of the SARS-CoV-2 virus in the oral cavity (the first entry point of the SARS-CoV-2 virus).

Propolis consumption by asymptomatic HIV-individuals: Better redox state? A prospective, randomized, double-blind, placebo-controlled trial

Propolis is a natural product has many biological properties of clinical interest, such as anti-inflammatory and antioxidant. Considering that people living with HIV/aids (PLWHA) on effective combined antiretroviral therapy (cART) present early aging due to an intense immune activation, inflammation, and redox imbalance, propolis consumption could offer a benefit to such patients. This double-blind longitudinal study evaluated whether Brazilian green propolis pills intake (500 mg/day for three months) would decrease the oxidative stress of virological suppressed HIV-individuals. To compare each group (propolis, n = 20 versus placebo, n = 20) in both moments (M0, before and M1, after the intervention), the following markers were assessed: plasma malondialdehyde (MDA), carbonylation, total oxide nitric, total antioxidant capacity (TAP), superoxide dismutase, catalase, and NFkB and NRF2 gene expression. Data were analyzed using Poisson, Gamma distribution and ANOVA followed by Tukey-Kramer. The groups were homogeneous regarding age, gender, time of diagnosis/ treatment, cART scheme, CD4⁺ T cell count, and no changes were observed in the diet food, or patients' lifestyles. A decreased MDA concentration was seen in the propolis group (M0 = 0.24 ± 0.13, M1 = 0.20 ± 0.10 protein nmol/mg; p = 0.005) as well as a slight but non-significant increase of TAP (M0 = 49.07 ± 13.26, M1 = 52.27 ± 14.86%; p = 0.06). One may conclude that propolis promoted a lower lipid peroxidation and improved the antioxidant system, suggesting that its use may be beneficial to PLWHA in an attempt to contain the intense inflammatory and oxidant activity.

In vitro antimicrobial activity of crude propolis extracts and fractions

The search for antimicrobials in propolis presents a new dimension for addressing the problem of antimicrobial drug resistance. The aim of this study was to determine the antimicrobial activity of extracts of crude propolis collected from different regions in Ghana and their active fractions. The antimicrobial activity of the extracts, as well as that of the chloroform, ethyl acetate, and petroleum ether fractions of the active samples were determined using the agar well diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the most active fractions were determined. The various crude propolis extracts frequently produced zones of inhibition against Staphylococcus aureus (17/20) than Pseudomonas aeruginosa (16/20), and Escherichia coli (1/20) test isolates. Chloroform and ethyl acetate solvents produced fractions possessing greater antimicrobial activity than the petroleum ether fraction. The mean MIC range of the most active fractions was greatest for S. aureus (76.0 ± 34.8-48.0 ± 33.0 mg/ml) than for P. aeruginosa (40.8 ± 33.3-30.4 ± 6.7 mg/ml) and E. coli, as was the mean MBC. Propolis has antimicrobial potential, and hence should be exploited as an alternative for the treatment of bacterial infections.

Development and Characterization of New Green Propolis Extract Formulations as Promising Candidates to Substitute for Green Propolis Hydroalcoholic Extract

The technologies used to produce the different dosage forms of propolis can selectively affect the original propolis compounds and their biological activities. The most common type of propolis extract is hydroethanolic. However, there is considerable demand for ethanol-free propolis presentations, including stable powder forms. Three propolis extract formulations were developed and investigated for chemical composition and antioxidant and antimicrobial activity: polar propolis fraction (PPF), soluble propolis dry extract (PSDE), and microencapsulated propolis extract (MPE). The different technologies used to produce the extracts affected their physical appearance, chemical profile, and biological activity. PPF was found to contain mainly caffeic and p-Coumaric acid, while PSDE and MPE showed a chemical fingerprint closer to the original green propolis hydroalcoholic extract used. MPE, a fine powder (40% propolis in gum Arabic), was readily dispersible in water, and had less intense flavor, taste, and color than PSDE. PSDE, a fine powder (80% propolis) in maltodextrin as a carrier, was perfectly water-soluble and could be used in liquid formulations; it is transparent and has a strong bitter taste. PPF, a purified solid with large amounts of caffeic and p-Coumaric acids, had the highest antioxidant and antimicrobial activity, and therefore merits further study. PSDE and MPE had antioxidant and antimicrobial properties and could be used in products tailored to specific needs.

Can egg yolk antibodies terminate the CSBV infection in apiculture?

Chinese sacbrood virus (CSBV) is the most severe pathogen of Apis cerana, which leads to serious fatal diseases in bee colonies and eventual catastrophe for the Chinese beekeeping industry. Additionally, CSBV can potentially infect Apis mellifera by bridging the species barrier and significantly affect the productivity of the honey industry. Although several approaches, such as feeding royal jelly, traditional Chinese medicine, and double-stranded RNA treatments, have been employed to suppress CSBV infection, their practical applicabilities are constrained due to their poor effectiveness. In recent years, specific egg yolk antibodies (EYA) have been increasingly utilized in passive immunotherapy for infectious diseases without any side effects. According to both laboratory research and practical use, EYA have demonstrated superior protection for bees against CSBV infection. This review provided an in-depth analysis of the issues and drawbacks in this field in addition to provide a thorough summary of current advancements in CSBV studies. Some promising strategies for the synergistic study of EYA against CSBV, including the exploitation of novel antibody drugs, novel TCM monomer/formula determination, and development of nucleotide drugs, are also proposed in this review. Furthermore, the prospects for the future perspectives of EYA research and applications are presented. Collectively, EYA would terminate CSBV infection soon, as well as will provide scientific guidance and references to control and manage other viral infections in apiculture.

The benefits of propolis in periodontal therapy. A scoping review of preclinical and clinical studies

ETHNOPHARMACOLOGICAL RELEVANCE

The treatment of periodontal disease (PD) is aimed at adequate control of bacterial plaque. In many patients mechanical methods are unable to eliminate this plaque leading to the need for adjuvant chemical products. Propolis is a natural product that has demonstrated therapeutic properties and has shown to be effective as an anti-inflammatory and antibacterial agent in dentistry.

AIM OF THE STUDY

Considering the beneficial effects of propolis on various oral conditions, this study aimed to review, update and summarize the available evidence on the benefits of propolis in in vitro studies, animal models, and human clinical trials on non-surgical periodontal therapy.

MATERIALS AND METHODS

An electronic search in three databases was performed up to December 2021. The search strategy included the terms "propolis" and "periodontal disease" to identify relevant studies on the potential advantages of propolis in periodontal therapy in in vitro studies, animal models, and human clinical trials.

RESULTS

The search yielded 538 results, discarding 459 studies that did not clearly meet the inclusion criteria. A total of 42 studies were included: 18 in vitro, one animal, and 23 randomized clinical trials. In vitro studies have demonstrated that propolis has antimicrobial activity against periodontal pathogens and clinical studies have reported its use as an adjunct to non-surgical periodontal therapy. The clinical effects of propolis have been reported in conjunction with prophylaxis, polishing, and scaling and root planing (SRP). It has shown to have anti-plaque activity and improve gingival health. Propolis was found to be more effective in improving clinical parameters than conventional treatment (SRP alone) and demonstrated similar efficacy in treating chronic periodontitis compared to positive controls. Only one study reported an allergic reaction.

CONCLUSION

The evidence available on the benefits of propolis in in vitro studies, animal models, and clinical trials suggests that propolis could be a promising adjunct to conventional therapy of gingivitis and periodontitis. However, further studies are needed to determine its superiority to other therapies in the treatment of PD.

Antifungal activity and mechanism of action of natural product derivates as potential environmental disinfectants

There have been a considerable number of antifungal studies that evaluated natural products (NPs), such as medicinal plants and their secondary metabolites, (phenolic compounds, alkaloids), essential oils, and propolis extracts. These studies have investigated natural antifungal substances for use as food preservatives, medicinal agents, or in agriculture as green pesticides because they represent an option of safe, low-impact, and environmentally friendly antifungal compounds; however, few have studied these NPs as an alternative to disinfection/sanitation for indoor air or environmental surfaces. This review summarizes recent studies on NPs as potential fungal disinfectants in different environments and provides information on the mechanisms of inactivation of these products by fungi. The explored mechanisms show that these NPs can interfere with ATP synthesis and Ca++ and K+ ion flow, mainly damaging the cell membrane and cell wall of fungi, respectively. Another mechanism is the reactive oxygen species effect that damages mitochondria and membranes. Inhibition of the overexpression of the efflux pump is another mechanism that involves damage to fungal proteins. Many NPs appear to have potential as indoor environmental disinfectants.

ONE-SENTENCE SUMMARY

This review shows the latest advances in natural antifungals applied to different indoor environments. Fungi have generated increased tolerance to the mechanisms of traditional antifungals, so this review also explores the various mechanisms of action of various natural products to facilitate the implementation of technology.

The synergistic effect of using bacteriophages and chitosan nanoparticles against pathogenic bacteria as a novel therapeutic approach

Public health and environmental security are seriously at risk due to the growing contamination of pathogenic microorganisms. Therefore, effective antimicrobials are urgently needed. In our study, the antimicrobial effects of three types of nanoparticles were investigated with phage. The biosynthesis of nanoparticles was confirmed based on the color change and shapes, which tended to be mono-dispersed with a spherical shape with a size range of 20-35 nm for Ag-CS-NPs; 15-30 nm for Phage-CS-NPs (Ph-CS-NPs); and 5-35 nm for Propolis-CS-NPs (Pro-CS-NPs). Nanoparticles displayed peaks between 380-420 nm, 335-380 nm, and below 335 nm for Ag-CS-NPs, Pro-CS-NPs, and Ph-CS NPs, respectively. Throughout the three synthesized nanoparticles, AgCs NPs represented a higher antibacterial effect in combination with phages. It showed MIC against S. sciuri, S. Typhimurium, and P. aeruginosa between 31.2 and 62.2 μg/mL and MBC at 500, 62.5, and 31.2 μg/mL, respectively, while in combination with phages showed MIC at 62.2, 31.2, and 15.6 μg/mL, respectively and MBC at 125, 62.2, and 15.6 μg/mL, respectively. Furthermore, a significant killing efficiency was observed with 16.5-30.1 μg/mL of Ag-CS NPs combined with phages. In conclusion, Ag-CS-NPs with phages present potential bactericidal and inhibitory effects against Gram-positive and Gram-negative bacteria, as well as against the production of biofilms.

The Effects of Propolis on Viral Respiratory Diseases

Propolis remains an interesting source of natural chemical compounds that show, among others, antibacterial, antifungal, antiviral, antioxidative and anti-inflammatory activities. Due to the growing incidence of respiratory tract infections caused by various pathogenic viruses, complementary methods of prevention and therapy supporting pharmacotherapy are constantly being sought out. The properties of propolis may be important in the prevention and treatment of respiratory tract diseases caused by viruses such as severe acute respiratory syndrome coronavirus 2, influenza viruses, the parainfluenza virus and rhinoviruses. One of the main challenges in recent years has been severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing COVID-19. Recently, an increasing number of studies are focusing on the activity of various propolis preparations against SARS-CoV-2 as an adjuvant treatment for this infection. Propolis has shown a few key mechanisms of anti-SARS-CoV-2 action such as: the inhibition of the interaction of the S1 spike protein and ACE-2 protein; decreasing the replication of viruses by diminishing the synthesis of RNA transcripts in cells; decreasing the particles of coronaviruses. The anti-viral effect is observed not only with extracts but also with the single biologically active compounds found in propolis (e.g., apigenin, caffeic acid, chrysin, kaempferol, quercetin). Moreover, propolis is effective in the treatment of hyperglycemia, which increases the risk of SARS-CoV-2 infections. The aim of the literature review was to summarize recent studies from the PubMed database evaluating the antiviral activity of propolis extracts in terms of prevention and the therapy of respiratory tract diseases (in vitro, in vivo, clinical trials). Based upon this review, it was found that in recent years studies have focused mainly on the assessment of the effectiveness of propolis and its chemical components against COVID-19. Propolis exerts wide-spectrum antimicrobial activities; thus, propolis extracts can be an effective option in the prevention and treatment of co-infections associated with diseases of the respiratory tract.

Neutrophil Immunomodulatory Activity of Nerolidol, a Major Component of Essential Oils from Populus balsamifera Buds and Propolis

Propolis is a resinous mixture of substances collected and processed from various botanical sources by honeybees. Black poplar (Populus balsamifera L.) buds are one of the primary sources of propolis. Despite their reported therapeutic properties, little is known about the innate immunomodulatory activity of essential oils from P. balsamifera and propolis. In the present studies, essential oils were isolated from the buds of P. balsamifera and propolis collected in Montana. The main components of the essential oil from P. balsamifera were E-nerolidol (64.0%), 1,8-cineole (10.8%), benzyl benzoate (3.7%), α-terpinyl acetate (2.7%), α-pinene (1.8%), o-methyl anisol (1.8%), salicylaldehyde (1.8%), and benzyl salicylate (1.6%). Likewise, the essential oil from propolis was enriched with E-nerolidol (14.4%), cabreuva oxide-VI (7.9%), α-bisabolol (7.1%), benzyl benzoate (6.1%), β-eudesmol (3.6%), T-cadinol (3.1%), 2-methyl-3-buten-2-ol (3.1%), α-eudesmol (3.0%), fokienol (2.2%), nerolidol oxide derivative (1.9%), decanal (1.8%), 3-butenyl benzene (1.5%), 1,4-dihydronaphthalene (1.5%), selina-4,11-diene (1.5%), α-cadinol (1.5%), linalool (1.4%), γ-cadinene (1.4%), 2-phenylethyl-2-methyl butyrate (1.4%), 2-methyl-2-butenol (1.3%), octanal (1.1%), benzylacetone (1.1%), and eremoligenol (1.1%). A comparison between P. balsamifera and propolis essential oils demonstrated that 22 compounds were found in both essential oil samples. Both were enriched in E-nerolidol and its derivatives, including cabreuva oxide VI and nerolidol oxides. P. balsamifera and propolis essential oils and pure nerolidol activated Ca²⁺ influx in human neutrophils. Since these treatments activated neutrophils, the essential oil samples were also evaluated for their ability to down-regulate the neutrophil responses to subsequent agonist activation. Indeed, treatment with P. balsamifera and propolis essential oils inhibited subsequent activation of these cells by the N-formyl peptide receptor 1 (FPR1) agonist fMLF and the FPR2 agonist WKYMVM. Likewise, nerolidol inhibited human neutrophil activation induced by fMLF (IC₅₀ = 4.0 μM) and WKYMVM (IC₅₀ = 3.7 μM). Pretreatment with the essential oils and nerolidol also inhibited human neutrophil chemotaxis induced by fMLF, again suggesting that these treatments down-regulated human neutrophil responses to inflammatory chemoattractants. Finally, reverse pharmacophore mapping predicted several potential kinase targets for nerolidol. Thus, our studies have identified nerolidol as a potential anti-inflammatory modulator of human neutrophils.

In Vitro Study on Green Propolis as a Potential Ingredient of Oral Health Care Products

Propolis is increasingly being discussed as an alternative to commonly used antiseptics. This in vitro study focused on the ethanolic extract of green Brazilian propolis (EEPg) as an additive in an oral health care product. We investigated (i) a potential inflammation-modulation activity of EEPg when a periodontal or Candida biofilm was exposed to monocytic (MONO-MAC-6) cells, (ii) the adhesion of oral pathogens to gingival keratinocytes and (iii) the antimicrobial and antibiofilm effect of different toothpaste formulations. EEPg decreased the levels of interleukin (IL)-1β and increased IL-10 in MONO-MAC cells challenged with a periodontal biofilm. In contact with TIGK cells, EEPg reduced the numbers of adherent Porphyromonas gingivalis to 0.5% but did not affect the adhesion of Candida albicans. The frequent brushing of a cariogenic biofilm with a toothpaste supplemented with EEPg reduced the surface microhardness loss of enamel specimens. Mixing an experimental erythritol toothpaste with 25 and 50 mg/mL of EEPg confirmed the antibacterial activity of EEPg against oral bacteria and particularly inhibited periodontal biofilm formation. The suggested toothpaste formulations seem to have potential in the prevention of caries, gingivitis and periodontitis and should be evaluated in further in vitro research and in clinical trials.

Mass Spectrometry-Based Identification of Bioactive Bee Pollen Proteins: Evaluation of Allergy Risk after Bee Pollen Supplementation

Bee pollen, because of its high content of nutrients, is a very valuable medicinal and nutritional product. However, since its composition is not completely studied, the consumption of this product may cause adverse effects, including allergic reactions. Therefore, this study aimed to discover and characterize the bioactive proteins of bee pollen collected in Poland, focusing mainly on the allergens. For this purpose, the purified and concentrated pollen aqueous solutions were analyzed using the nanoLC-MALDI-TOF/TOF MS analytical platform. As a result of the experiments, 197 unique proteins derived from green plants (Viridiplantae) and 10 unique proteins derived from bees (Apis spp.) were identified. Among them, potential plant allergens were discovered. Moreover, proteins belonging to the group of hypothetical proteins, whose expression had not been confirmed experimentally before, were detected. Because of the content of bioactive compounds-both beneficial and harmful-there is a critical need to develop guidelines for standardizing bee pollen, especially intended for consumption or therapeutic purposes. This is of particular importance because awareness of the allergen content of bee pollen and other bee products can prevent health- or life-threatening incidents following the ingestion of these increasingly popular "superfoods".

Bud-Poplar-Extract-Embedded Chitosan Films as Multifunctional Wound Healing Dressing

Wounds represent a major global health challenge. Acute and chronic wounds are sensitive to bacterial infection. The wound environment facilitates the development of microbial biofilms, delays healing, and promotes chronic inflammation processes. The aim of the present work is the development of chitosan films embedded with bud poplar extract (BPE) to be used as wound dressing for avoiding biofilm formation and healing delay. Chitosan is a polymer with antimicrobial and hydrating properties used in wound dressing, while BPE has antibacterial, antioxidative, and anti-inflammatory properties. Chitosan-BPE films showed good antimicrobial and antibiofilm properties against Gram-positive bacteria and the yeast Candida albicans. BPE extract induced an immunomodulatory effect on human macrophages, increasing CD36 expression and TGFβ production during M1/M2 polarization, as observed by means of cytofluorimetric analysis and ELISA assay. Significant antioxidant activity was revealed in a cell-free test and in a human neutrophil assay. Moreover, the chitosan-BPE films induced a good regenerative effect in human fibroblasts by in vitro cell migration assay. Our results suggest that chitosan-BPE films could be considered a valid plant-based antimicrobial material for advanced dressings focused on the acceleration of wound repair.

Chemical Composition and Biological Activity of Argentinian Propolis of Four Species of Stingless Bees

The chemical composition of propolis of four species of stingless bees (SLBs) from Argentina was determined, and its antibacterial and anticancer activity was evaluated on selected types of microbes and cancer cell lines. Volatile secretions of all propolis samples are formed by 174 C₂-C₁₅ organic compounds, mainly mono- and sesquiterpenes and their derivatives. The chromatograms of ether extracts showed 287 peaks, of which 210 were identified. The most representative groups in the extracts of various propolis samples were diterpenoids (mainly resin acids), triterpenoids and phenolic compounds: long-chain alkenyl phenols, resorcinols and salicylates. The composition of both volatile and extractive compounds turned out to be species-specific; however, in both cases, the pairwise similarity of the propolis of Scaptotrigona postica and Tetragonisca fiebrigi versus that of Tetragona clavipes and Melipona quadrifasciata quadrifasciata was observed, which indicated the similarity of the preferences of the respective species when choosing plant sources of resin. The composition of the studied extracts completely lacked flavonoids and phenolcarboxylic acids, which are usually associated with the biological activity and medicinal properties of propolis. However, tests on selected microbial species and cancer cell lines showed such activity. All propolis samples tested against Paenibacillus larvae, two species of Bacillus and E. coli showed biofilm inhibition unrelated to the inhibition of bacterial growth, leading to a decrease in their pathogenicity. Testing the anticancer activity of ether extracts using five types of cell cultures showed that all four types of propolis studied inhibit the growth of cancer cells in a dose- and time-dependent manner. Propolis harvested by T. clavipes demonstrated the highest cytotoxicity on all tested cell lines.

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

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