Intervention and follow-up
Propolis and placebo capsules were prepared by Asal Shahdineh Golha Co., Isfahan, Iran. The propolis sample was collected during the fall season from beehives located in Isfahan, Iran, verified by an expert agricultural organization. Each propolis capsule contained 125 mg poplar type propolis ethanol extract, 187.5 mg bee pollen, and 187.5 mg oat, a total amount of 36 mg phenolic compounds (expressed as gallic acid equivalent). According to Bankova recommendation for chemical standardization of poplar type propolis