To bee or not to bee? The bee extract propolis as a bioactive compound in the burden of lifestyle diseases

Effects of Propolis Supplementation on Gut Microbiota and Uremic Toxin Profiles of Patients Undergoing Hemodialysis

BACKGROUND

Propolis possesses many bioactive compounds that could modulate the gut microbiota and reduce the production of uremic toxins in patients with chronic kidney disease (CKD) undergoing hemodialysis (HD). This clinical trial aimed to evaluate the effects of propolis on the gut microbiota profile and uremic toxin plasma levels in HD patients. These are secondary analyses from a previous double-blind, randomized clinical study, with 42 patients divided into two groups: the placebo and propolis group received 400 mg of green propolis extract/day for eight weeks. Indole-3 acetic acid (IAA), indoxyl sulfate (IS), and p-cresyl sulfate (p-CS) plasma levels were evaluated by reversed-phase liquid chromatography, and cytokines were investigated using the multiplex assay (Bio-Plex Magpix®). The fecal microbiota composition was analyzed in a subgroup of patients (n = 6) using a commercial kit for fecal DNA extraction. The V4 region of the 16S rRNA gene was then amplified by the polymerase chain reaction (PCR) using short-read sequencing on the Illumina NovaSeq PE250 platform in a subgroup. Forty-one patients completed the study, 20 in the placebo group and 21 in the propolis group. There was a positive correlation between IAA and TNF-α (r = 0.53, p = 0.01), IL-2 (r = 0.66, p = 0.002), and between pCS and IL-7 (r = 0.46, p = 0.04) at the baseline. No significant changes were observed in the values of uremic toxins after the intervention. Despite not being significant, microbial evenness and observed richness increased following the propolis intervention. Counts of the Fusobacteria species showed a positive correlation with IS, while counts of Firmicutes, Lentisphaerae, and Proteobacteria phyla were negatively correlated with IS. Two months of propolis supplementation did not reduce the plasma levels of uremic toxins (IAA, IS, and p-CS) or change the fecal microbiota.

Advancing ecotoxicity assessment: Leveraging pre-trained model for bee toxicity and compound degradability prediction

The prediction of ecological toxicity plays an increasingly important role in modern society. However, the existing models often suffer from poor performance and limited predictive capabilities. In this study, we propose a novel approach for ecological toxicity assessment based on pre-trained models. By leveraging pre-training techniques and graph neural network models, we establish a highperformance predictive model. Furthermore, we incorporate a variational autoencoder to optimize the model, enabling simultaneous discrimination of toxicity to bees and molecular degradability. Additionally, despite the low similarity between the endogenous hormones in bees and the compounds in our dataset, our model confidently predicts that these hormones are non-toxic to bees, which further strengthens the credibility and accuracy of our model. We also discovered the negative correlation between the degradation and bee toxicity of compounds. In summary, this study presents an ecological toxicity assessment model with outstanding performance. The proposed model accurately predicts the toxicity of chemicals to bees and their degradability capabilities, offering valuable technical support to relevant fields.

Using the concept of food as medicine to mitigate inflammation in patients undergoing peritoneal dialysis

The most common kidney replacement therapy (KRT) worldwide is hemodialysis (HD), and only 5%-10% of patients are prescribed peritoneal dialysis (PD) as KRT. Despite PD being a different method, these patients also present particular complications, such as oxidative stress, gut dysbiosis, premature aging, and mitochondrial dysfunction, leading to an inflammation process and high cardiovascular mortality risk. Although recent studies have reported nutritional strategies in patients undergoing HD with attempts to mitigate these complications, more information must be needed for PD patients. Therefore, this review provides a comprehensive analysis of recent studies of nutritional intervention to mitigate inflammation in PD patients.

COVID-19 and Nutrition: Focus on Chronic Kidney Disease

Some chronic diseases, including chronic kidney disease (CKD), may be associated with poor outcomes, including a high rate of hospitalization and death after COVID-19 infection. In addition to the vaccination program, diet intervention is essential for boosting immunity and preventing complications. A healthy diet containing bioactive compounds may help mitigate inflammatory responses and oxidative stress caused by COVID-19. In this review, we discuss dietary interventions for mitigating COVID-19 complications, including in persons with CKD, which can worsen COVID-19 symptoms and its clinical outcomes, while diet may help patients with CKD to resist the ravages of COVID-19 by improving the immune system, modulating gut dysbiosis, mitigating COVID-19 complications, and reducing hospitalization and mortality. The concept of food as medicine, also known as culinary medicine, for patients with CKD can be extrapolated to COVID-19 infection because healthy foods and nutraceuticals have the potential to exert an important antiviral, anti-inflammatory, and antioxidant role.

Protect the Kidneys and Save the Heart Using the Concept of Food as Medicine

Chronic kidney disease is a significant risk factor for cardiovascular disease. In addition to traditional risk factors, such as hypertension, dyslipidemia, diabetes and smoking, patients with chronic kidney disease have a uremic phenotype marked by premature aging, mitochondrial dysfunction, persistent low-grade inflammation, gut dysbiosis and oxidative stress. These complications contribute to abnormal vascular and myocardial remodeling processes, resulting in accelerated vascular calcification, cellular and organ senescence and a high risk of cardiovascular disease. Nonpharmacological strategies, such as increasing physical activity and a healthy diet, may slow the progression of kidney disease and consequently protect the heart. Thus, a deep promotion and advocacy of nutritional guidance based on scientific data is needed. This narrative review discusses how nutritional interventions may delay progressive organ damage in the kidney-heart axis.

Gut Microbiota Interventions to Retain Residual Kidney Function

Residual kidney function for patients with chronic kidney disease (CKD) is associated with better quality of life and outcome; thus, strategies should be implemented to preserve kidney function. Among the multiple causes that promote kidney damage, gut dysbiosis due to increased uremic toxin production and endotoxemia need attention. Several strategies have been proposed to modulate the gut microbiota in these patients, and diet has gained increasing attention in recent years since it is the primary driver of gut dysbiosis. In addition, medications and faecal transplantation may be valid strategies. Modifying gut microbiota composition may mitigate chronic kidney damage and preserve residual kidney function. Although various studies have shown the influential role of diet in modulating gut microbiota composition, the effects of this modulation on residual kidney function remain limited. This review discusses the role of gut microbiota metabolism on residual kidney function and vice versa and how we could preserve the residual kidney function by modulating the gut microbiota balance.

The effect of Brazilian Green Propolis extract on inflammation in patients with chronic kidney disease on peritoneal dialysis: A randomised double-blind controlled clinical trial

BACKGROUND

Chronic kidney disease (CKD) patients on dialysis display a low-grade systemic inflammatory burden. Nutritional interventions designed to activate the cytoprotective nuclear factor erythroid-2-related factor 2 (Nrf2) and inhibit nuclear factor-kB (NF-κB) have been proposed to mitigate this burden. Several bioactive compounds have been investigated to achieve this, including propolis, a resin produced by Apis mellifera bees. Considering the safety and efficacy of propolis, it could be a strategy to benefit these patients. Still, there are no studies using propolis in patients with CKD on peritoneal dialysis (DP), and clinical studies to support this application are lacking.

HYPOTHESIS/PURPOSE

The objective and novelty of the present study are to evaluate the effects of propolis supplementation on inflammatory markers in patients with CKD on PD.

STUDY DESIGN

A longitudinal, double-blind, placebo-controlled trial with CKD patients on PD.

METHODS

The patients were randomised into two groups: propolis that received four capsules of 100 mg (400 mg/day), containing concentrated and standardised dry EPP-AF® Brazilian green propolis extract) or placebo, four capsules of 100 mg (400 mg/day), of magnesium stearate, silicon dioxide, and microcrystalline cellulose, for two months. Plasma levels of inflammatory cytokines, including tumour necrosis factor (TNF-α) and interleukin-6 (IL-6), were evaluated by ELISA. Quantitative real-time PCR analyses were performed to evaluate the transcriptional expression levels of Nrf2 and NF-κB in peripheral blood mononuclear cells (PBMCs). Plasma malondialdehyde (MDA) levels, a lipid peroxidation marker, was measured as thiobarbituric acid reactive substances (TBARS). Routine biochemical markers, including C-reactive protein (CRP), were analysed using commercial kits. Carotid Intima-Media Thickness (CIMT) was measured with a doppler ultrasonography device. The study was registered on ClinicalTrials.gov under the number NCT04411758.

RESULTS

A total of 19 patients completed the study, ten patients in the propolis group (54 ± 1.0 years, five men, 7.2  (5.1) months on PD) and 9 in the placebo group (47.5 ± 15.2 years, three men, 10.8  (24.3) months on PD). The plasma levels of TNF-α reduced significantly (p = 0.02), and expression of Nrf2 showed a trend to increase (p = 0.07) after propolis supplementation.

CONCLUSION

EPP-AF® Green Propolis extract (400 mg/day) supplementation for two months appears as a potential strategy to mitigate inflammation, reducing TNF-α plasma levels in CKD patients on PD.

Genotoxicity and toxicological evaluations of Brazilian red propolis oral ingestion in a preclinical rodent model

ETHNOPHARMACOLOGICAL RELEVANCE

Brazilian red propolis is a natural product known due to its medicinal properties. The efficacy of this natural resin has been proved; however, few studies report the safety of its oral use. Some toxic effects of natural products may not be expressed in traditional use, and preclinical studies are necessary to guarantee their safety. Health regulatory agency currently requires these non-clinical studies to develop drugs and herbal medicines, including genotoxic and oral toxicity tests.

AIM OF THE STUDY

Accomplish the preclinical toxicity studies of Brazilian red propolis extract (BRP) in rodents, including genotoxicity, acute and sub-chronic toxicities.

MATERIAL AND METHODS

Genotoxicity assays followed the erythrocyte micronucleus test protocol in a range of 500-2000 mg/kg BRP oral treatment on male Swiss mice. After an up-and-down procedure, acute oral toxicity (single dose) was performed on female Wistar Hannover rats, reaching a 2000 mg/kg BRP oral gavage concentration. Animals were monitored periodically until 14 days and euthanized for a macroscopic necropsy analysis. The sub-chronic oral toxicity test (90 days) was achieved with 1000 mg/kg of BRP on Wistar Hannover rats (males/females). Animals were monitored to evaluated behavioral and biometrical changes, then were euthanized to perfomed hematological, biochemical, and histopathological analyses.

RESULTS

No genotoxic effect of the BRP was detected. The acute toxicity indicated no toxicity of a single oral dose of 2000 mg/kg of BRP. The long-term oral toxicity performed with 1000 mg/kg of BRP altered water and food intake and the biometrics, hematological and biochemical parameters. Biochemical alterations in hepatic and renal parameters were detected only in the males. Despite the detection of biochemical alterations, no histopathological changes were detected in the organs of any group.

CONCLUSIONS

BRP, at a higher dose, showed no signs of immediate toxicity. However, the obtained results suggest that the chemical composition and the intake of higher doses deserve special attention regarding possible toxicity.

Effects of propolis on inflammation markers in patients undergoing hemodialysis: A randomized, double-blind controlled clinical trial

BACKGROUND AND AIMS

Several studies have been performed in vitro and in animals showing that propolis (a resin made by bees) has excellent anti-inflammatory properties, but no study has been performed in patients with chronic kidney disease (CKD) on hemodialysis (HD). The present study aimed to evaluate the effects of propolis supplementation on inflammatory markers in patients with CKD on HD.

METHODS

This is a longitudinal, double-blind, placebo-controlled trial with patients randomized into two groups: propolis (4 capsules of 100 mg/day containing concentrated and standardized dry EPP-AF® green propolis extract) or placebo (4 capsules of 100 mg/day containing microcrystalline cellulose, magnesium stearate and colloidal silicon dioxide) for two months. Routine parameters were analyzed using commercial kits. The plasma levels of inflammatory cytokines were evaluated by flow luminometry.

RESULTS

Forty-one patients completed the follow-up, 21 patients in the propolis group (45 ± 12 years, 13 women, BMI, 22.8 ± 3.7 kg/m²) and 20 in the placebo group (45.5 ± 14 years, 13 women, BMI, 24.8 ± 6.8 kg/m²). The obtained data revealed that the intervention with propolis significantly reduced the serum levels of tumour necrosis factor α (TNFα) (p = 0.009) as well as had the tendency to reduce the levels of macrophage inflammatory protein-1β (MIP-1β) (p = 0.07). There were no significant differences in the placebo group.

CONCLUSION

Short-term EPP-AF® propolis dry extract 400 mg/day supplementation seems to mitigate inflammation, reducing the plasma levels of TNFα and MIP-1β in patients with CKD on HD. This study was registered at clinicaltrials.gov (NCT04411758).

Cinnamon: an aromatic condiment applicable to chronic kidney disease

Cinnamon, a member of the Lauraceae family, has been widely used as a spice and traditional herbal medicine for centuries and has shown beneficial effects in cardiovascular disease, obesity, and diabetes. However, its effectiveness as a therapeutic intervention for chronic kidney disease (CKD) remains unproven. The bioactive compounds within cinnamon, such as cinnamaldehyde, cinnamic acid, and cinnamate, can mitigate oxidative stress, inflammation, hyperglycemia, gut dysbiosis, and dyslipidemia, which are common complications in patients with CKD. In this narrative review, we assess the mechanisms by which cinnamon may alleviate complications observed in CKD and the possible role of this spice as an additional nutritional strategy for this patient group.

Inhibitory activities of propolis, nisin, melittin and essential oil compounds on Paenibacillus alvei and Bacillus subtilis

Background

Natural products represent important sources of antimicrobial compounds. Propolis and compounds from essential oils comprise good examples of such substances because of their inhibitory effects on bacterial spores, including bee pathogens.

Methods

Ethanol extracts of propolis (EEP) from Apis mellifera were prepared using different methods: double ultrasonication, double maceration and maceration associated with ultrasonication. Together with the antimicrobial peptides nisin and melittin, and compounds present in the essential oils of clove (Syzygium aromaticum) and cinnamon (Cinnamomum zeylanicum), assays were carried out on one Bacillus subtilis isolate and Paenibacillus alvei (ATCC 6344) against vegetative and sporulated forms, using the resazurin microtiter assay. Synergism with all the antimicrobials in association with tetracycline was verified by the time-kill curve method. Potassium and phosphate efflux, release of proteins and nucleic acids were investigated.

Results

EEPs showed the same MIC, 156.25 µg/mL against B. subtilis and 78.12 µg/mL against P. alvei. The peptides showed better activities against B. subtilis (MIC of 12 µg/mL for melittin and 37.50 µg/mL for nisin). Antimicrobials showed similar inhibitory effects, but cinnamaldehyde (39.06 µg/mL) showed the best action against P. alvei. Melittin and nisin showed the greatest capacity to reduce spores, regarding B. subtilis there was a 100% reduction at 6.25 and 0.78 µg/mL, respectively. Concerning P. alvei, the reduction was 93 and 98% at concentrations of 80 µg/mL of melittin and 15 µg/mL of nisin. EEPs showed the highest effects on the protein release against B. subtilis and P. alvei. Nucleic acid release, phosphate and potassium efflux assays indicated bacterial cell membrane damage. Synergism between antimicrobials and tetracycline was demonstrated against both bacteria.

Conclusion

All antimicrobials tested showed antibacterial activities against vegetative and sporulated forms of P. alvei and B. subtilis, especially nisin and melittin. Synergism with tetracycline and damage on bacterial cell membrane also occurred.

Effect of honey and propolis, compared to acyclovir, against Herpes Simplex Virus (HSV)-induced lesions: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Apitherapy is a branch of traditional medicine that uses bee products to manage numerous diseases. In this context, the antiherpetic effect of these bee products has been demonstrated in some studies with some controversial results.

AIM OF THE STUDY

Thus, we conducted a systematic review and meta-analysis to compare the effectiveness of honey and propolis with acyclovir, the reference drug, in the treatment of cold sores and genital herpes.

MATERIALS AND METHODS

The selection of eligible studies was conducted through the search in Pubmed/MEDLINE, Scopus, Cochrane Library, LILACS, and Electronic Scientific Library.

RESULTS

The search yielded 147 articles, of which nine were considered eligible for analysis. The analysis of these studies showed that the healing property of propolis is superior to that obtained for acyclovir (95% CI: 2.70 to 8.25; p = 0.0001). Furthermore, honey also presented a better healing effect than acyclovir against Herpes simplex virus-induced wounds (95% CI: 3.58 to -0.19; p = 0.03), inducing complete re-epithelization of herpetic lesions after 8 days, while for acyclovir, the healing time average was 9 days. It also provoked a similar reduction of pain caused by herpetic compared to acyclovir (95% CI: 2.27 to -0.42; p = 0.18).

CONCLUSIONS

Overall, these results confirm the use of honey and propolis as potent antiherpetic agents.

Propolis from the Monte Region in Argentina: A Potential Phytotherapic and Food Functional Ingredient

The aim of this review is to provide overall information on Argentine propolis and to shed light on its potential, especially the one from the Monte region so as to support future research in the field. Around 1999, the Argentine propolis began to be chemically and functionally characterized to give it greater added value. Because Argentina has a wide plant biodiversity, it is expected that its propolis will have various botanical origins, and consequently, a different chemical composition. To date, five types have been defined. Based on their functionality, several products have been developed for use in human and veterinary medicine and in animal and human food. Because the Argentine propolis with the greatest potential is that of the Monte eco-region, this review will describe the findings of the last 20 years on this propolis, its botanical source (Zuccagnia punctata Cav.), its chemical composition, and a description of markers of chemical quality (chalcones) and functionality. Propolis can regulate the activity of various pro-inflammatory enzymes and carbohydrate and lipid metabolism enzymes, as well as remove reactive oxygen and nitrogen species. Consequently, it can modulate metabolic syndrome and could be used as a functional ingredient in food. Furthermore, hydroalcoholic extracts can act against human and animal pathogenic bacteria and human yeast, and mycelial pathogenic fungi. The ability to stop the growth of post-harvest pathogenic bacteria and fungi was also demonstrated. For this reason, Argentine propolis are natural products capable of protecting crops and increasing the lifespan of harvested fruit and vegetables. Several reports indicate the potential of Argentine propolis to be used in innovative products to improve health, food preservation, and packaging. However, there is still much to learn about these natural products to make a wholesome use of them.