Radioprotective Effects of Quercetin and Ethanolic Extract of Propolis in Gamma-Irradiated Mice

Abstract

The aim of this study was to assess radioprotective effects of quercetin and the ethanolic extract of propolis (EEP) in CBA mice exposed to a single radiation dose 4 Gy ( 60 Co). The mice were treated with 100 mg kg -1 quercetin or EEP a day for three consecutive days either before (pre-treatment) or after gamma-irradiation (therapy). Leukocyte count was determined in blood drawn from the tail vein, and DNA damage in leukocytes was assessed using the alkaline comet assay. Genotoxic effects of the test compunds were also evaluated in non-irradiated mice. The levels of radioprotection provided by both test compounds were compared with those established in mice that were given chemical radioprotector S-(2-Aminoethyl)isothiouronium bromide hydrobromide (AET). Mice that received pre-treatment were less sensitive to irradiation. Mice given the post-irradiation therapy showed a slight but not signifi cant increase in total leukocyte count over irradiated negative control. Quercetin showed better protective properties than EEP in both pre-treatment and therapy, and activated a higher number of leukocytes in non-irradiated mice. The alkaline comet assay suggests that both natural compounds, especially when given as pre-treatment, protect against primary leukocyte DNA damage in mice. At tested concentrations, EEP and quercetin were not genotoxic to non-irradiated mice. AET, however, caused a slight but not signifi cant increase in DNA damage. Although the results of this study show the radioprotective potential of the test compounds, further investigation is needed to clarify the underlying protection mechanisms.

Hepatic Nrf2 expression is altered by quercetin supplementation in X-irradiated rats

“…Quercetin has been used as pre-treatment to radiation in mice (16) and other flavonoids have been tested both prior to and following irradiation (17). The present study has demonstrated the radiomitigative effects of quercetin when administered for four days prior to and six days following whole-body X-irradiation.…”

“…Quercetin has been successfully tested as an antioxidant in several in vitro studies using cell cultures (16,39,40), but its in vivo activity has been questioned. Studying vitamin E-deficient rats supplemented with vitamin E or a variety of flavonoids, including quercetin, Duthie et al (41) concluded that in vivo supplementation with these antioxidant compounds (100 mg/kg diet) is ineffective in restoring lipid peroxidation indices in plasma and liver.…”

Evaluation of Protective Effect of Propolis on Parotid Salivary Glands in Gamma-irradiated Rats

“…All of these compounds are responsible for its biological and pharmacological properties. [14][15][16][17] According to pharmacological characteristics of propolis and lack of data about its effects on salivary glands as well as its reasonable price and good historical safety profile, we decided to use propolis in our study.…”

Combined effect of viscous dissipation and thermal radiation on fluid flows over a non-linearly stretched permeable wall

“…It has been described that between them, the constituents with major contribution in the radioprotective effect are the flavonoids. Some of the radioprotective mechanisms are scavenger potency against free radicals [30], immunological properties [10], protection against inflammatory responses [9], protection against fetal effects of radiation, and apoptosis in cancer cells [2]. Moreover, Kunimasa et al [24] have demonstrated that flavonoids have antioxidative potency in vitro and in vivo, protect mice against lethal effects of whole-body irradiation, and diminish primary DNA damage [4].…”

“…Propolis has shown protect against the induction of apoptosis by radiation; since it is an imunomodulator, it has antioxidative and cytotoxic activities, antitumor activities, and scavenges free radicals produced by the indirect effect of ionizing radiation [2,[7][8][9][10][11][12]. Moreover, several reports have demonstrated the ability of EEP to protect mice against gamma irradiation preventing exaggerated inflammatory response [9], promoting high survival in mice [10], protecting their whole blood cells, and also diminishing primary DNA damage in mice [4,13].…”