Propolis

Vitamin C from Oranges 🍊

Propolis is a natural substance that bees produce from plant resins and use to seal their hives. It has many health benefits, such as healing wounds, preventing infections, and improving oral hygiene. Propolis contains antioxidants, flavonoids, and other compounds that may have anti-inflammatory, antibacterial, antifungal, and antiviral effects123.

Some people take propolis as a dietary supplement, either in capsule, liquid, or powder form. Others apply it topically to the skin, especially for minor cuts, burns, or cold sores. Propolis may also be used in some dental products, such as mouthwash and toothpaste, to prevent plaque and cavities23.

However, propolis is not safe for everyone. Some people may be allergic to propolis or its components, which can cause skin rashes, swelling, or breathing problems. Propolis may also interact with some medications, such as blood thinners or drugs that are metabolized by the liver enzyme cytochrome P450. Therefore, it is important to consult your doctor before using propolis if you have any medical conditions or take any medications123.

Propolis is a fascinating product of nature that has been used for centuries by humans and bees alike. It is a testament to the amazing abilities of these tiny insects to create something so useful and beneficial from the plants around them. I hope you learned something new about propolis today 😊.

Propolis 🐝

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Antioxidant 'bee glue' creates buzz for new Australian industry
by University of the Sunshine Coast

Antioxidant 'bee glue' creates buzz for new Australian industry
Murray Arkadieff searching for propolis on the live hive. Credit: University of the Sunshine Coast
A nutrient-rich product discovered in honeybee hives across Australia could generate a new homegrown health industry.

University of the Sunshine Coast researchers have identified for the first time 16 types of Australian high-grade propolis, or "bee glue," brimming with enough antioxidants and other chemical properties to spark a new national industry for food and health products.

The findings have excited the UniSC team led by chemistry academics Dr. Trong Tran and Dr. Peter Brooks, who previously collaborated on national research that found exceptional antibacterial activity in Australian manuka honey.

Propolis is a sticky mixture used by honeybees in the construction of their hives. It usually contains beeswax, bee saliva and resin from the native and non-native plants that bees pollinate.

In the Australian beekeeping industry, propolis is regularly discarded as a nuisance product. In countries such as Brazil, China and New Zealand, it is harvested for use in multi-million-dollar food and cosmeceutical industries.

Dr. Tran said the two-year collaborative project had found the superior qualities in propolis scraped from honeybee hives across the country, including four in Southeast Queensland.

Beekeeper Murray Arkadieff, whose hives near Ipswich produced some of the most active propolis samples in the state, said the positive findings provided opportunities for a new revenue stream for Australian beekeepers and more industry jobs.

"This will help to further reinforce the exceptionally high quality of Australian honey and our hive products both in Australia, and internationally," said Arkadieff.

The paper in Scientific Reports assessed the quality and chemical diversity of Australian propolis from Apis mellifera or European honeybees, common across the country.

Dr. Tran said the research confirmed the chemical makeup of 16 propolis samples had more potent antioxidant activity than some well-known international types generating big profits overseas.

"Established cosmeceutical industries add propolis to products intended to have both cosmetic and therapeutic benefits, such as mouth sprays, soap, toothpaste, dietary supplements and skincare creams," he said. "In the food and beverage industry, propolis can be a preservative."

Dr. Tran said propolis had been used in many cultures for centuries as a natural antibiotic, but research papers since the 1990s had increasingly found much more than antimicrobial potential, including the possibility of adjunct treatments for cancers and COVID-19.

Researchers and co-authors from Hive and Wellness Australia said the findings were very encouraging for the beekeeping industry, which currently has 530,000 honeybee hives.

"At the moment, we only have small-scale propolis production, mainly in South Australia," said Dr. Ben McKee, Chief Operating Officer at Hive and Wellness.

"More domestic harvesting would provide extra income for beekeepers and processors while reducing the reliance on imported propolis in manufacturing.

"This research could be a solid foundation to build a new industry across the country."

The UniSC team recently published three papers on propolis. Dr. Tran said the next step would be tracing the plant sources of the samples, to inform plant biodiversity measures and hive locations.

"This study indicates Australia has the capability to produce unique and premium propolis types because of its unique and diverse native flora," he said.

The paper was authored by UniSC's Dr. Tran and Dr. Brooks with Chau Tran, Tahmikha Bryen and Dr. Simon Williams, and Hive and Wellness Australia's Jessica Berry, Fiona Tavian and Ben McKee.

It followed an AgriFutures Australia report in 2019 that recommended further research to help Australia grow its propolis production and market. It reported that the farm gate value of propolis production to New Zealand beekeepers was averaging $NZ3.75 million a year.

AgriFutures Honey Bee & Pollination Program Research Manager Annelies McGaw said the findings could strengthen the industry.

"The annual contribution of the honey bee to our economy is $14.2 billion, however over recent years this industry has been severely impacted by bushfires, floods and pest incursions like Varroa mite," McGaw said.

"Although there is still more work to do to better understand the benefits of propolis, the potential commercialization could provide a very welcome and timely income stream for Australian beekeepers

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JOURNAL ARTICLE
In vitro antimicrobial activity of crude propolis extracts and fractions
Alhassan Sa-eed, Eric S Donkor, Reuben E Arhin, Patience B Tetteh-Quarcoo, Simon K Attah, Daniel E K Kabotso, Fleischer C N Kotey, Nicholas T K D Dayie
FEMS Microbes, Volume 4, 2023, xtad010, https://doi.org/10.1093/femsmc/xtad010
Published: 20 April 2023 Article history
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Abstract
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.

antimicrobial, activity, crude, propolis, extracts, fractions
Issue Section: Microbes & Disease
Introduction
Medicinal plants and their derivatives play a vital role in covering the basic health needs in under-resourced settings (WHO 1998). One of such plant derivatives is bee propolis (bee glue), a resin-type substance made up of a complex mixture of several substances mainly collected from tree sap and leaf buds by the honeybee, Apis mellifera (Orsi et al. 2005). It has been considered a good candidate for the prevention and treatment of infectious diseases (Orsi et al. 2005). The increasing use of propolis in modern traditional medicine has attracted researchers to investigate its chemical composition and antimicrobial properties (Amoros et al. 1992, Huang et al. 2014). This is because propolis is of plant-based origins and may offer the possibility of discovering unique and important phytochemicals for the treatment of infectious diseases.

Currently, antimicrobial drug resistance is having a serious impact on healthcare and economies around the globe (WHO 2014). In Ghana, antimicrobial drug therapy constitutes a major form of treatment for infectious diseases (Opintan et al. 2015). The Antimicrobial Drug use, Monitoring, and Evaluation of Resistance project (ADMER 2015) revealed the seriousness of the increasing resistance of bacteria to conventional antimicrobial drugs in Ghana. Across the southern, central, and northern sectors of Ghana, varied levels of resistance have been recorded. Recently, a multicenter antimicrobial resistance surveillance study in the country revealed alarming rates of resistance against Gram-negative bacteria isolated from blood stream infections (Donkor et al. 2023). Succinctly put, the enormity of the antimicrobial resistance menace has limited the therapeutic use of antimicrobial drugs for the treatment and control of many infectious diseases (Opintan et al. 2015, Addae-Nuku et al. 2022, Baah et al. 2022, Dayie et al. 2022, Dwomoh et al. 2022, Kotey et al. 2022, Donkor et al. 2023). This phenomenon threatens the success of medical interventions, and presents a set of specific challenges for clinical, therapeutic, and public health measures both nationally and internationally (WHO 2014). As a result, there has been a continuous search for antimicrobial compounds present in natural products. Concentrated whole plant extracts have been adopted in forms such as infusions, creams, and pills as part of a holistic treatment plan to address the antimicrobial drug resistance menace. Propolis has gained attention as part of the search for alternative antimicrobial agents from natural products to combat drug-resistant bacteria (Ali et al. 2018).

The search for antimicrobials in propolis presents a new dimension for addressing the problem of resistance to antimicrobial drugs. The aim of this study was to determine the antimicrobial activity of crude propolis extracts and selected solvent-derived fractions collected from different regions in Ghana.

Materials and methods
Sampling sites
Propolis samples were collected from selected commercial beekeepers from each of the then 10 regions of Ghana covering a total land area of 238 535 km2. Beekeepers in Ghana [Upper West Region (UWR), Upper East Region (UER), Northern Region (NR), Brong Ahafo Region (BAR), Ashanti Region (AR), Eastern Region (ER), Western Region (WR), Greater Accra Region (GAR), Volta Region (VR), and Central Region (CR)] are known for capturing wild bees and do not use hive chemicals (Llorens-Picher et al. 2017); hence selection was based on the vegetation cover and regional location of the hive. One hive was selected from each region.

Preparation of the crude extract solutions
The crude extract solutions were prepared using the method described by Fabricant and Fansworth (2001). The collected propolis were sorted to remove pieces of wood, embalmed insects, and other animals. The samples were air dried under a shed and pulverized. For each sample, 30 g was weighed and dissolved in absolute ethanol. This was kept for 72 hours and filtered twice using Whatman No.1 filter paper. Each filtrate was evaporated using a rotary evaporator to obtain a solid mass, which was subsequently dried in a desiccator. Using 5% dimethyl sulfoxide (DMSO) (Daejung, Korea) as a solvent, solutions of 64 mg/ml were prepared for each dry solid mass obtained.

Antimicrobial screening of the crude extract solutions
The prepared solutions were tested for antimicrobial activity using the agar well diffusion method. Clinical isolates characterized by multidrug resistance, such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) obtained from the Microbiology Laboratory of the Center for Plant Medicine Research, Mampong, were used to prepare inocula of cell densities 106 cells/ml using the direct colony suspension method. These were used alongside S. aureus ATCC 25923, E. coli NCTC 13351, and P. aeruginosa ATCC 27853 quality control strains.

For each prepared inoculum, a sterile swab stick was moistened in the inoculum and used to inoculate the surface of Mueller-Hinton agar plates. A 6-mm diameter sterile c**k borer was used to create wells of 3 mm depth in each Mueller-Hinton agar plate and filled with 100 μl of each crude extract solution; 5% DMSO was included for testing as a negative control. The plates were incubated at 37 °C for 18 hours, and the diameter of each zone of inhibition was measured (Asiedu-Gyekye et al. 2005, Dayie et al. 2008, CLSI 2016).

Fractionation of the selected crude extract dried masses
Based on observation of the antimicrobial activities from the screening, the NR, ER, VR, and AR crude extract dried masses were selected. Using a separatory funnel, analytical grades of chloroform (CH), ethyl acetate (EA), and petroleum ether (PE) (British Drug House and Fruka) solvents were used for the extraction of polar, medium polar, and nonpolar bioactive components, respectively. A rotary evaporator was used to remove the extraction solvents from each fraction to obtain dry soluble masses of the extracts.

Antimicrobial activity of the fractions
The dry masses obtained were resuspended in 5% DMSO. The antimicrobial activity of each fraction was determined in biological duplicates using the agar well diffusion method, as previously described for the screening. Each well of the Mueller-Hinton agar plate was filled with 100 μl of the fraction and the plates were incubated at 37 °C for 18 hours. The diameter of each zone of inhibition was measured (Dayie et al. 2008, CLSI 2016). Kirby-Bauer disk diffusion tests using vancomycin, amikacin, and clindamycin commercial reference antibiotic disks were utilized as positive controls.

Fractions showing a zone of inhibition >15 mm against at least two test bacteria were selected on observation, and their minimum inhibitory concentrations (MIC) were determined using the macrobroth dilution method (CLSI 2016).

The lowest concentration of the fractions that prevented visible growth of the test bacteria in the Mueller-Hinton broths was subcultured onto Mueller-Hinton agar plates. The plates were incubated at 37 °C for 18 hours and checked for growth. The lowest concentration of each fraction for which there was no growth after subculturing on the Mueller-Hinton agar plates was recorded as the minimum bactericidal concentration (MBC) for the fraction. An illustration of the study methodology is presented in Fig. 1.

Figure 1.
Illustration of the study methodology.
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Illustration of the study methodology.

Data analysis
StataMP14 was used to analyze the data. Means were computed for zones of inhibition produced by the crude propolis, propolis fractions, and reference antibiotic disks. Unpaired t-tests were performed to determine the significance of the difference between the means of the crude extract zones for each clinical isolate and their corresponding type strain. One sample t-test was performed to determine the significance of the difference between the means of the crude propolis extract zones and the reference zones. One-way ANOVA was used to determine if there was any statistically significant difference across the MICs and MBCs of the effective crude propolis fractions. Post hoc analysis was performed by the Bonferroni test. P values