INS and type 2 diabetes mellitus: Consistent with our results, Samadi et al. and Zakerkish et al. verified that bee propolis causes a notable reduction in blood glucose, serum insulin, and glycosylated hemoglobin (HbA1c) levels, along with improved insulin resistance in type 2 diabetes patients (Samadi et al., 2017; Zakerkish et al., 2019).