Anti-Allergic Properties of Propolis: Evidence From Preclinical and Clinical Studies

Abstract

Allergic diseases are a global health burden with increasing prevalence. Side effects of available medications (antihistamines and steroids), lack of patients’ perceived effectiveness and high cost of biologic therapies (omalizumab) are challenges to the clinical management of allergic diseases. As allergy symptoms persist for a long time, complementary and alternative medicine (CAM) such as propolis may be considered a potential prophylactic or therapeutic option to avoid long-term medication use. Propolis is a natural resinous substance produced by bees. Although propolis is well known to possess antioxidant, antimicrobial, and anticancer properties, its anti-allergic potential is not fully explored. Several preclinical studies demonstrated the therapeutic effects of propolis extracts against allergic inflammation, asthma, allergic rhinitis, atopic dermatitis, and food allergy, which may be partly attributed to their inhibitory effects on the activation of mast cells and basophils. Clinically, the consumption of propolis as a supplement or an adjunct therapy is safe and attenuates various pathological conditions in asthma. Such an approach may be adopted for atopic dermatitis and allergic rhinitis. Although flavonoids (chrysin, kaempferol, galangin, and pinocembrin) and cinnamic acid derivatives (artepillin C and caffeic acid phenethyl ester) can contribute to the anti-allergic activities, they may not be present in all propolis samples due to variations in the chemical composition. Future studies should relate the anti-allergic activity of propolis with its chemical contents. This mini-review summarizes and discusses existing preclinical and clinical studies reporting the anti-allergic activities of propolis to provide insights into its potential applications in allergic diseases.

Perspectives for Uses of Propolis in Therapy against Infectious Diseases

“…In fact, Brazilian propolis has been shown to exert anti-allergic properties due to inhibitory effects on the activation of mast cells and basophils. Preclinical studies demonstrated the effects of propolis extracts against allergic symptoms, such as inflammation, asthma, rhinitis, atopic dermatitis, and food allergy, most studies having been carried out with Brazilian green propolis [ 113 ]. It remains to be determined which components of propolis account for the anti-allergic activity.…”

Allergic Inflammation: Effect of Propolis and Its Flavonoids

“…Some of them also work in a spasmogenic way or activate respiratory burst and degranulation of leukocytes [ 54 , 55 , 56 , 69 , 70 , 71 , 72 ]. Thus, lipoxygenase plays a decisive role in pathological processes, such as inflammation or allergies [ 54 , 55 , 56 , 70 , 71 , 125 , 126 ]. Moreover, certain enzymatic products of lipoxygenases are thought to be essential for tumorigenesis [ 65 ].…”

“…Therefore, hydroxylated resveratrol analogues represent a novel class of highly selective COX-2 inhibitors and promising candidates for in vivo studies. Furthermore, promising in vitro data indicated that treatment with selective COX-2 inhibitors such as curcumin, chlorogenic acid, CA, resveratrol, galangin or the flavonoid silymarin may reduce the risk of Alzheimer’s, and Parkinson’s disease [ 142 , 143 ] and also be effective in the treatment of asthma and other allergic diseases [ 125 , 136 , 144 , 145 ].…”

“…It appears that EGCG has protective effects on airway remodeling in asthma and may be useful as an adjuvant therapy for bronchial asthma [ 180 , 181 , 182 ]. The therapeutic potential of propolis is evident in allergic disorders caused by fungal allergens such as conidia of Aspergillus fumigatus , which cause allergic inflammation in people suffering from allergic bronchopulmonary aspergillosis (ABPA), allergic Aspergillus sinusitis and asthma [ 125 , 183 ]. The intake of propolis ethanol extract reduces the production of pro-inflammatory cytokines IL-13 and IL-17 and increases the production of IL-12.…”

“…Propolis and related flavonoids have been shown to control specific allergic reactions including allergic rhinitis, asthma, different skin allergy, rheumatoid arthritis, atopic dermatitis, bronchitis, ocular allergy and others [ 125 , 136 , 154 , 254 , 255 , 256 , 257 ]. Thus, flavonoids, can regulate a number of allergic, autoimmune and inflammatory diseases, including cancer, through blockade of eosinophils and basophils, as important mediator cells in allergy and inflammation ( Figure 7 a,b).…”