INTRODUCTION
Propolis is a waxy mixture produced by honey bees from substances collected from plants, buds, and exudates. Propolis is made of about 50% resins, 30% waxes, 10% essential oils, 5% pollen, and 5% of various organic compounds. Propolis is used by bees for construction and repair of their hives. Propolis is also known as bee glue. Propolis has anti-microbial properties, and has been used for cold syndrome (e.g. common cold, flu-like infections etc.), wound healing, burns, acne, herpes simplex and genitalis and neurodermatitis. [8a] Propolis is also applied in a number of daily products, including lip balms, cosmetics, lotions and ointments, shampoos, conditioners, and toothpastes. [1,2]
Propolis is found to have antiinflammatory, antioxidative, anti-ulcer, anti-tumor, cholesterol and blood pressure lowering activities. Intake of propolis may provide health benefits. [1-6] In the last few years, researchers have focused its effects on infection, it is interesting to understand its potential health benefits on its users.
POTENTIAL HEALTH BENEFITS - Infection and COVID 19
Propolis was found to have benefits of activities against a range of commonly encountered cocci and Gram-positive rods, including the human tubercle bacillus, but only limited activity against Gram-negative bacilli. [7]
Propolis may have particular health benefits against COVID 19, based on the following arguments and studies: Scientists from Brazil argue that SARS-CoV-2 entry into host cells via a viral spike protein interaction with cellular angiotensin-converting enzyme 2 (ACE2) and serine protease TMPRSS2. This mechanism involves PAK1 overexpression, which is a kinase that mediates coronavirus-induced lung inflammation, fibrosis, and immune system suppression. Propolis components have inhibitory effects on the ACE2, TMPRSS2 and PAK1 signaling pathways. Propolis has shown benefits for COVID-19 patients. (D1) Further, researchers from Indonesia analyzed the interaction profiles of propolis compounds with SARS-CoV-2 main protease. They reported that glyasperin A and broussoflavonol F, are potential drug candidates for COVID-19, their argument is based on their binding affinity of −7.8 kcal/mol and their ability to interact with His41 and Cys145 as catalytic sites. (D2) In another study, scientists from Egypt suggested propolis liposomes as a promising therapeutic approach for COVID-19. In vitro studies, they found the inhibition of viral replication of COVID-19 has been significantly enhanced via encapsulation of propolis extract within the liposomal formulation and was comparable to the viral inhibitory effect of the potent antiviral (remdesivir). (D3)
In a clinical study, a supplement of Echinacea angustifolia, rosehip, propolis, royal jelly and zinc was provided to long COVID patients, This study showed the supplement's beneficial effects on the inflammatory state, fatigue and quality of life. (D4)
COMPOSITION OFF PROPOLIS
The chemical composition of propolis is quite complicated. It has more than 300 compounds such as polyphenols, phenolic aldehydes, sequiterpene quinines, coumarins, amino acids, steroids and inorganic compounds. [6] The contents depend on the collecting location, time and plant source. Consequently, biological activities of propolis gathered from different phytogeographical areas and time periods vary greatly. [1,4]
SIDE EFFECTS OF PROPOLIS
Reports of allergic reactions are not uncommon. More 200 cases of dermatitis of propolis have been reported, including the first description of 'poplar bud' contact dermatitis from 1887. [7] 1.2 to 6.6% of patients who are patch-tested for dermatitis are sensitive to propolis. The main allergens are 3-methyl-2-butenyl caffeate and phenylethyl caffeate. Benzyl salicylate and benzyl cinnamate are less frequent sensitizers. [2] Propolis is relatively non-toxic, with a no-effect level (NOEL) in a 90-mouse study of 1400 mg/kg body weight/day. [5]
REFERENCE
[1] Khalil ML. Biological activity of bee propolis in health and disease. Asian Pac J Cancer Prev. 2006 Jan-Mar;7(1):22-31.
[2] Walgrave SE, et al, Allergic contact dermatitis from propolis. Dermatitis. 2005 Dec;16(4):209-15.
[3] Castaldo S, Capasso F. Propolis, an old remedy used in modern medicine. Fitoterapia. 2002 Nov;73 Suppl 1:S1-6.
[4] Banskota AH, et al, Recent progress in pharmacological research of propolis. Phytother Res. 2001 Nov;15(7):561-71.
[5] Burdock GA. Review of the biological properties and toxicity of bee propolis (propolis). Food Chem Toxicol. 1998 Apr;36(4):347-63.
[6] Gallo FR, Savi G. Propolis: its use in technology and researchBoll Chim Farm. 1995 Oct;134(9):483-91. [7] Grange JM, Davey RW. Antibacterial properties of propolis (bee glue). J R Soc Med. 1990 Mar;83(3):159-60.
[7] Hausen BM, et al, Propolis allergy. (I). Origin, properties, usage and literature review. Contact Dermatitis. 1987 Sep;17(3):163-70. [8a] Adv Pharmacol Sci. 2013; 2013: 308249.
D1. Biomed Pharmacother. 2020 Nov; 131: 110622
D2. J King Saud Univ Sci. 2021 Jan; 33(1): 101234
D3. Int J Pharm. 2021 Jan 5; 592: 120028
D4. Annalisa Noce et al, Potential Anti-Inflammatory and Anti-Fatigue Effects of an Oral Food Supplement in Long COVID Patients,Pharmaceuticals (Basel). 2024 Apr 5;17(4):463.