One of the most important approaches in the prevention and treatment of nosemosis is the use of herbal preparations as food supplements for bees. Therefore, the aim of this study was to investigate the effects of a plant-based supplement branded as “B+” on honeybees in a laboratory experiment. Four experimental groups were established: treated group (T), N. ceranae-infected and treated group (IT), N. ceranae-infected group (I) and non-infected group (NI). Survival, N. ceranae spore load and oxidative stress parameters together with expression levels of antioxidant enzyme genes and vitellogenin gene were monitored. The mortality in the T, IT and NI groups was significantly (p Nosema-infected groups, the IT group had a significantly lower (p N. ceranae spores than the I group. In addition, expression levels of genes for antioxidant enzymes were lower (p p N. ceranae spore number and reduced oxidative stress of bees (lower expression of genes for antioxidant enzymes and oxidative stress parameters).
