Evaluation of Radioprotective Effects of Propolis and Quercetin on Human White Blood Cells in Vitro

Abstract

Growing clinical, toxicological and biochemical evidence supports the use of different natural products as adjunct treatment for patients exposed to radiation as well as in chemopreventive strategies. Propolis has gained popularity as a health natural product extensively used in food and beverages to improve human health and to prevent diseases such as inflammation, heart disease and even cancer.1) The wide spectrum of propolis activities was mainly attributed to the large number of flavonoids. In addition to flavonoids, propolis contains phenolic acids, esters, enzymes, vitamins and minerals. 2-4)The flavonoids possess many biological properties being strong antioxidants and have antimicrobial, antiinflammatory/antialergic, antimutagenic, anticlastogenic and anticarcinogenic properties.1,5-7) Antioxidant activity of flavonoids is based on ability of direct scavenging of reactive oxygen, nitrogen and chlorine species, such as superoxide, hydroxyl radical, peroxyl radicals, hypochlorous acid, and peroxynitrous acid. Because of the high reactivity of the hydroxyl substituents of the flavonoids, radicals are made inactive. Flavonoids can also increase the function of the endogenous antioxidant enzyme systems.8) Furthermore, their antioxidant effects may be a result of a combination of radical scavenging and an interaction with enzyme functions. Growing evidences suggest that flavonoids prevent oxidative damage of DNA (single strand breaks, double strand breaks, oxidative damage to sugar and base residues, chromosomal aberration and mutation) and other cellular components. They may interact with cellular drug transport systems and transmembrane transport, interfere with cyclin-dependent regulation of the cell cycle, inhibiting telomerase, affecting signal transduction pathways, inhibiting cyclooxygenases and lypooxygenases, decreasing xantine oxidase, metalloproteinase and sulfotransferase activities. 9)Quercetin is one of the most abundant dietary flavonoids present in fruits and vegetables and its average human daily intake in various countries is estimated to be approximately 25 mg.10) Based on the structure-activity relationships for antioxidant effects, quercetin appears to be one of the most active flavonoids.1) It has greatest pharmacological activities among the flavonoids and possesses potential therapeutic applications. In Ames test, quercetin is regarded as mutagenic, however, recent in vitro studies indicate that quercetin is protective against genotoxicants, and regarded as antimutagenic.11)The aim of present in vitro study on human white blood cells was to estimate radioprotective effects of natural substances propolis and quercetin. The effectiveness of tested compounds was evaluated by the alkaline comet assay, the analysis of structural chromosomal aberrations and cytokinesis-block micronucleus assay. Moreover, possible genotoxic effects of the compounds were also assessed on non-irradiated blood samples. MATERIALS AND METHODS Blood SamplingTo overcome possible inter-individual variability in respon...

Jamun (<i>Syzygium cumini </i>(L.)): A Review of Its Food and Medicinal Uses

“…2 Quercetin 1) Protected yeast cells from γ-radiation damage by reducing DNA damage [110]; 2) Effective inprotecting against γ-radiation-induced DNA damage to the human peripheral blood lymphocytes in vitro [104, and plasmid DNA [111]. The protective mechanisms were mediated by the antioxidant and inhibition of lipid peroxides [111]; 3) Intraperitoneal administration of quercetin 100 mg·kg/kg for 3 consecutive days before and/or after irradiation prevented radiation induced DNA damage in WBC of mice.…”

“…The protective mechanisms were mediated by the antioxidant and inhibition of lipid peroxides [111]; 3) Intraperitoneal administration of quercetin 100 mg·kg/kg for 3 consecutive days before and/or after irradiation prevented radiation induced DNA damage in WBC of mice. Pronounced effects were when querecetin was administered before radiation [112,113] 3 Gallic acid 1) Inhibits radiation-induced damage to DNA and lipid peroxidation in both in vitro and in vivo conditions [114].…”

In vitro assessment of the cytotoxic, DNA damaging, and cytogenetic effects of hydroquinone in human peripheral blood lymphocytes

“…The outcomes of treatment were evaluated using the apoptosis/necrosis assay, the alkaline comet assay, and the cytokinesis-block micronucleus (CBMN) cytome assay. All of these methods are wellestablished in genetic toxicology and have proven useful in studies with different plant extracts or their active constituents (18)(19)(20)(21)(22)(23)(24)(25)(26).…”

Radioprotective effect and other biological benefits associated with flavonoids

“…Additionally, propolis flavonoids [66][67][68], glabridin [69], austragalus [70,71] and flavonoids of Oxytropis falcate Bunge also inhibited the secretion of inflammatory factors secondary to radiation exposure, and reduced the body's inflammatory response.…”