Brazilian Green Propolis Extract

SARS-CoV-2 and its different variants caused a "wave and wave" pandemic pattern. During the first wave we demonstrated that standardized Brazilian green propolis extract (EPP-AF®) reduces length of hospital stay in adult patients with COVID-19. Afterwards, we decided to evaluate the impact of EPP-AF in hospitalized patients during the third wave of the pandemic. BeeCovid2 was a randomized, double-blind, placebo-controlled clinical trial in hospitalized COVID-19 adult patients. Patients were allocated to receive an oral dose of 900 mg/day of EPP-AF® or placebo for 10 days. The primary outcome was length of hospital stay. Secondary outcomes included safety, secondary infection rate, duration of oxygen therapy dependency, acute kidney injury and need for intensive care. Patients were followed up for 28 days after admission. We enrolled 188 patients; 98 were assigned to the propolis group and 90 to the placebo group. The post-intervention length of hospital stay was of 6.5 ± 6.0 days in the propolis group versus 7.7 ± 7.1 days in the control group (95% CI - 0.74 [- 1.94 to 0.42]; p = 0.22). Propolis did not have significant impact on the need for oxygen supplementation or frequency of AKI. There was a significant difference in the incidence of secondary infection between groups, with 6.1% in the propolis group versus 18.9% in the control group (95% CI - 0.28 [0.1-0.76], p = 0.01). The use of EPP-AF was considered safe and associated with a decrease in secondary infections. The drug was not associated with a significant reduction in length of hospital stay. ClinicalTrials.gov (NCT04800224).

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.

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.

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

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.

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.

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.