1. Antiviral activity of different extracts of standardized propolis preparations against HSV.

Background: Viral infections are among the most common problems in healthcare practice. Natural products offer great promise as potentially effective antiviral drugs. Propolis is a honeybee product with biological properties and therapeutic applications. We aimed to investigate the antiviral activity of different extracts of Standardized Propolis Preparations (M.E.D.®) with glycol, ethanol, glycerol, and soya oil, against herpes simplex type 1 (HSV1) and type 2 (HSV-2) viruses. Methods: Chemical composition and antiviral activity of each extract were determined. The selective index (SI=CC50/EC50) was determined as a parameter to indicate the in-vitro antiviral activity of the extracts compared to acyclovir as the control. Results: SI values of glycol, ethanol, glycerol, soya oil extracts and acyclovir were determined as 6.8, 4.1, 2.2, 3.3, and 6.3 against HSV-1, and as 6.4, 7.7, 1.9, 4.2, and 2.9 against HSV-2, respectively. Glycolic propolis extract was found to possess a greater antiviral activity than acyclovir for both HSV type 1 and type 2, while glycolic, ethanolic, and soya oil preparations were found to have more significant activity than acyclovir for HSV-2. Conclusions: It was determined that standardized propolis preparations have antiviral bioactivity against HSV. [Demir S, 1, Atayoglu AT, Galeotti F, et al. Antiviral activity of different extracts of standardized propolis preparations against HSV. Antivir Ther. 2020;25(7):353-363.

2. A standardized polyphenol mixture extracted from poplar-type propolis for remission of symptoms of uncomplicated upper respiratory tract infection (URTI): A monocentric, randomized, double-blind, placebo-controlled clinical trial.

Background: The most common symptoms of mild upper respiratory tract infections (URTIs) are sore throat, muffled dysphonia, and swelling and redness of the throat, which result from the inflammation process following acute bacterial or viral infection. Hypothesis/purpose: As propolis is a natural resinous substance traditionally used to maintain oral cavity and upper respiratory tract health due to its antimicrobial and anti-inflammatory properties, the aim of this study is to evaluate the efficacy of an oral spray based on poplar-type propolis extract with a known and standardized polyphenol content, on the remission of the symptoms associated with mild uncomplicated URTIs. Study design: A monocentric, randomized, double-blind, placebocontrolled clinical trial was performed. Methods: This study was conducted in 122 healthy adults who had perceived mild upper respiratory tract infections. Participants, randomly assigned to receive either propolis oral spray (N = 58) or placebo (N = 64), underwent four visits (baseline = t0, after 3 days = t1 and after 5 days = t2 and after a follow-up of 15 days = t3) in an outpatient setting. Propolis oral spray total polyphenol content was 15 mg/ml. The dosage was 2-4 sprays three times/day (corresponding to 12-24 mg of polyphenols/day), for five days. The duration of the study was 8 weeks. Results: After 3 days of treatment, 83% of subjects treated with propolis oral spray had remission of symptoms, while 72% of subjects in the placebo group had at least one remaining symptom. After five days, all subjects had recovered from all symptoms. This February 22, 2022 means that resolution from mild uncomplicated URTIs took place two days earlier, instead of taking place in five days as recorded in the control group. There was no relationship between the ingestion of propolis oral spray or placebo and adverse reactions. Conclusion: Propolis oral spray can be used to improve both bacterial and viral uncomplicated URTI symptoms in a smaller number of days without the use of pharmacological treatment, leading to a prompt symptom resolution. [Esposito C, Garzarella EU, Bocchino B, et al. A standardized polyphenol mixture extracted from poplar-type propolis for remission of symptoms of uncomplicated upper respiratory tract infection (URTI): A monocentric, randomized, double-blind, placebo-controlled clinical trial. Phytomedicine. 2021;80:153368.]

3. Multi dynamic extraction: an innovative method to obtain a standardized chemically and biologically reproducible polyphenol extract from poplar-type propolis to be used for its anti-infective properties.

Background: Antimicrobial activity is a well-known property of propolis, making it a candidate for antimicrobial surfaces in biomedical devices. Nevertheless, large-scale use of propolis as an anti-infective agent is limited by the heterogeneity of its chemical composition and consequent variation in antimicrobial activity. The aim of this study was to demonstrate that the multi dynamic extraction (M.E.D.) method produces standardized polyphenolic mixtures from poplar-type propolis, with reproducible chemical composition and anti-microbial activity, independently from the chemical composition of the starting raw propolis. Three raw propolis samples, from Europe, America, and Asia, were analyzed for their polyphenol chemical composition by means of HPLC-UV and then combined to obtain three mixtures of propolis, which werme submitted to the M.E.D. extraction method. The chemical composition and the antimicrobial activity of M.E.D. propolis against bacteria and fungi were determined. The three M.E.D. propolis showed similar chemical compositions and antimicrobial activities, exhibiting no relevant differences against antibiotic-susceptible and antibiotic-resistant strains. The batch-to-batch reproducibility of propolis extracts obtained with the M.E.D. method encourages the design of drugs alternative to traditional antibiotics and the development of anti-infective surface-modified biomaterials. [Zaccaria V, Garzaraella EU, Di Giovanni C, et al. Multi dynamic extraction: an innovative method to obtain a standardized chemically and biologically reproducible polyphenol extract from poplar-type propolis to be used for its anti-infective properties. Materials (Basel). 2019 Nov 13;12(22):3746.

4. Bioavailability and in vivo antioxidant activity of a standardized polyphenol mixture extracted from brown propolis.

Background: Several lines of evidence demonstrate the antioxidant, anti-inflammatory and antimicrobial activities of propolis, mostly ascribed to its polyphenol content. However, little is known regarding the bioavailability of propolis in acute and prolonged settings of oral administration. In this study, we first determined the content of the main polyphenols in a brown propolis extract obtained using a patented extraction method (Multi Dinamic Extraction-M.E.D.) by RP-HPLCUV-PDA-MSn analysis, followed by the bioavailability of galangin and chrysin, the most February 22, 2022 abundant polyphenols in the mixture (7.8% and 7.5% respectively), following acute (single bolus of 500 mg/kg containing about 3.65 mg of the polyphenol mixture) and prolonged (100, 250 and 500 mg/kg body for 30 days) oral administration in 30 male 8 weeks old C57BL/6 wild-type mice. In the acute setting, blood was taken at 30 s and 5, 10, 15, 20, 25, 30, 45, 60 and 120 min following the oral bolus. In the prolonged setting, blood samples were obtained after 10, 20 or 30 days of administration. At the end of treatment, expression of antioxidant enzymes (superoxyde dismutase, SOD-1; catalase, CAT; glutathione peroxidase, GSS) was evaluated in liver tissue. Following both acute and prolonged administration, neither galangin nor chrysin were detectable in the plasma of mice, whereas the glucuronide metabolite of galangine was detectable 5 min after acute administration. At the end of the prolonged treatment SOD-1 was found to have increased significantly, unlike CAT and GSS. Overall, these data suggest that oral administration of whole brown propolis extract is followed by rapid absorption and metabolization of galangin followed by adaptations of the antioxidant first line defense system. [Curti V, Zaccaria V, Sokeng AJT, et al. Bioavailability and in vivo antioxidant activity of a standardized polyphenol mixture extracted from brown propolis. Int J Mol Sci. 2019;20(5):1250.]

5. Effect of green and brown propolis extracts on the expression levels of microRNAs, mRNAs and proteins, related to oxidative stress and inflammation.

Abstract: A large body of evidence highlights that propolis exerts many biological functions that can be ascribed to its antioxidant and anti-inflammatory components, including different polyphenol classes. Nevertheless, the molecular mechanisms are yet unknown. The aim of this study is to investigate the mechanisms at the basis of propolis anti-inflammatory and antioxidant activities. The effects of two brown and green propolis extracts—chemically characterized by RP-HPLC-PDA-ESI-MSn—on the expression levels of miRNAs associated with inflammatory responses (miR-19a-3p and miR-203a-3p) and oxidative stress (miR-27a-3p and miR-17-3p), were determined in human keratinocyte HaCat cell lines, treated with non-cytotoxic concentrations. The results showed that brown propolis, whose major polyphenolic components are flavonoids, induced changes in the expression levels of all miRNAs, and was more active than green propolis (whose main polyphenolic components are hydroxycinnamic acid derivatives) which caused changes only in the expression levels of miR-19a-3p and miR-27a-3p. In addition, only brown propolis was able to modify (1) the expression levels of mRNAs, the target of the reported miRNAs, which code for Tumor Necrosis Factor-α (TNF-α), Nuclear Factor, Erythroid 2 Like 2 (NFE2L2) and Glutathione Peroxidase 2 (GPX2), and (2) the protein levels of TNF-α and NFE2L2. In conclusion, brown and green propolis, which showed different metabolite profiles, exert their biological functions through different mechanisms of action. [Zaccaria V, Curti V, Di Lorenzo A, et al. Effect of green and brown propolis extracts on the expression levels of microRNAs, mRNAs and proteins, related to oxidative stress and inflammation. Nutrients. 2017;9(10):1090.] February 22, 2022

6. Effectiveness of a standardized propolis extract in non-surgical periodontal therapy.

We determined the polyphenol content in a defined volume of chemically characterized and standardized propolis sample to evaluate its effectiveness in patients with chronic periodontitis. After having determined the polyphenol content of a given volume of propolis extract and characterized the molecular profile, 150 patients were enrolled, randomly divided into three groups and subjected to three different treatments, Scaling and Root planing (SRP) associated with propolis, SRP with 1% chlorhexidine gel and SRP only. Before the treatments, Full Mouth Plaque Score (FMPS), Pocket Depth at Probing (PPD), Full Mouth Bleeding Score (FMBS), Impaired furcations according to the Hamp Classification, Mobility, Gingival recession and Clinical Attack Level (CAL) were evaluated. A significant reduction of all the studied variables was observed in the three examined groups even if in the group treated with propolis, after 6 weeks, the reduction, and therefore the improvement, was higher than SRP treatment alone and in the presence of 1% chlorhexidine gel. Finally, there were no significant differences in the reduction of PPD and CAL between the groups treated with chlorhexidine and the group treated with SRP alone. Compared to the other two groups, Subjects treated with 10.4 mg propolis showed a significant improvement in all four variables. This study shows that propolis could be used as a natural adjuvant in the treatment of periodontal disease. [Salvatori C, Bernardo M, Colonna A, et al. Effectiveness of a standardized propolis extract in non-surgical periodontal therapy. J Oral Infect Pathol. 2021;1:104.]