Effects of Propolis from Mount Ida on Hemocyte-Mediated Immune Responses of Galleria mellonella (Lepidoptera: Pyralidae)

Propolis, an important bee product, has been used for centuries for therapeutic purposes. In recent decades, Galleria mellonella larvae have been widely used as infection assessments for microbial pathogens and antimicrobial properties. The aim of this study investigates the influence of propolis ethanolic extract on the immune responses mediated by hemocytes in G. mellonella. Phase-contrast microscopy was used to examine the immune responses to encapsulation-melanization and total hemocyte count. Our results indicated that propolis extract increased the number of G. mellonella hemocytes at doses higher than 46 mg/mL; however, it leads to a reduction in encapsulation and melanization responses. We concluded that although the addition of propolis ethanolic extract to the G. mellonella diet increased the number of hemocytes, it decreased the encapsulation and melanisation responses in the long term and thus did not show the expected positive effects on immunity.