A Pilot Study on the Immunomodulatory Effect of Bulgarian Propolis

Effects of ginger extract and/or propolis extract on immune system parameters of vaccinated broilers

Newcastle disease (ND), avian influenza (AI, H5N8), and infectious bronchitis (IB) are important diseases in the poultry industry and cause significant losses. Vaccination is the most practical method for controlling infectious diseases. To reduce vaccination costs and several disorders in poultry farms, using herbal water supplements for immunomodulation with vaccination is critical to improving or preventing some conditions in the poultry industry. However, drinking water supplementation of ginger extract (GE)/propolis extract (PE) alone/in combination may increase broilers' humoral and cellular immunity due to the immunomodulatory effects of ginger and propolis. This protocol aimed to see how GE/PE alone or in combination improved the immunity, immune organ gene expression, and histology of the immune organs of broilers for 35 d after vaccination against NDV, H5N8, IBV, and IBDV. The chicks were dispensed into 5 groups according to GE and/or PE with vaccination. The control group was offered normal drinking water without any supplements or vaccinations. The GE group was supplemented with ginger extract (1 mL/L drinking water) in the drinking water before and after vaccination for 2 and 3 d, respectively. The GE+PE group was supplemented with GE (0.5 mL/L drinking water) and PE (0.5 mL/L drinking water) in the drinking water before and after vaccination for 2 and 3 d, respectively. The PE group was supplemented with propolis extract (1 mL/L drinking water) in the drinking water before and after vaccination for 2 and 3 d, respectively. The fifth group was the vaccinated untreated group. This experiment showed the immunomodulatory properties of GE and/or PE against 3 common diseases, NDV, AI, and IB, in broiler chicken farms for 35 d applied to a vaccination program. Thus, ginger extract and propolis extract supplementation in drinking water increased antibody titer, INF, IL10, and IL2 and TLR3 gene expression in the bursa of Fabricius, thymus, and spleen, respectively, as well as cellular immunity as indicated by increased CD3, CD4, and CD8 in the bursa of Fabricius, thymus, and spleen, respectively, with normal lymphocytes in the medulla of the bursa, thymus, and spleen. In conclusion, propolis extracts alone or with GE improved all of the metrics mentioned above without harming the histology of the immune organs.

The antiviral and immunomodulatory activities of propolis: An update and future perspectives for respiratory diseases

Propolis is a complex natural product that possesses antioxidant, anti‐inflammatory, immunomodulatory, antibacterial, and antiviral properties mainly attributed to the high content in flavonoids, phenolic acids, and their derivatives. The chemical composition of propolis is multifarious, as it depends on the botanical sources from which honeybees collect resins and exudates. Nevertheless, despite this variability propolis may have a general pharmacological value, and this review systematically compiles, for the first time, the existing preclinical and clinical evidence of propolis activities as an antiviral and immunomodulatory agent, focusing on the possible application in respiratory diseases. In vitro and in vivo assays have demonstrated propolis broad‐spectrum effects on viral infectivity and replication, as well as the modulatory actions on cytokine production and immune cell activation as part of both innate and adaptive immune responses. Clinical trials confirmed propolis undeniable potential as an effective therapeutic agent; however, the lack of rigorous randomized clinical trials in the context of respiratory diseases is tangible. Since propolis is available as a dietary supplement, possible use for the prevention of respiratory diseases and their deleterious inflammatory drawbacks on the respiratory tract in humans is considered and discussed. This review opens up new perspectives on the clinical investigation of neglected propolis biological properties which, now more than ever, are particularly relevant with respect to the recent outbreaks of pandemic respiratory infections.