Investigation of the effect of honey, pollen, propolis and royal jelly extracts on the enzyme activities of thioredoxin reductase under in vitro conditions

Honey, having thousands of years of history, is a food substance naturally obtained from flower essence of many plant and secretion essence of plant body. Due to the fact that the source is a plant origin, it has been determined that it has high phenolic content and its antioxidant and antimicrobial properties have been studied in the literature. This situation has created need to research of the effects of honey and important products of honey production process which are pollen, propolis and royal jelly on cancer called as plague of this era. With this study effects of some honey and some bee product on Thioredoxin reductase (TrxR) enzyme activity that triggering cancer formation was investigated under in-vitro conditions and total phenolic contents of sample was calculated. In this study, hexane, ethanol, methanol, DMSO and water extracts of pine honey, chestnut honey, spring honey, mad honey, pollen, propolis and royal jelly were prepared. Inhibition effects was investigated on TrxR enzyme activity of the extracts by using DTNB method. The hexane extracts of the samples could not be tested for TrxR inhibition since they formed two phases with enzyme buffer. IC50 values for TrxR inhibition of ethanol, methanol, DMSO and water extracts of other samples were calculated and it was found that at least one extract of each sample inhibited TrxR enzyme. It was determined that pollen methanol extract showed the highest inhibition with IC50 value of 0.024 mg/mL. In the study, the total phenolic content of the extracts were examined by Folin-Ciocalteu method and the highest phenolic content was found to be pollen-DMSO extract with 1.151,0 mg GAE/g. As a result of the study, it has been found that honey and other bee products, which they are rich phenolic content have, inhibitory effect on TrxR enzyme activity which supports cancer formation.