title: Effect of Brazilian propolis (AF-08) on genotoxicity, cytotoxicity and clonogenic death of Chinese hamster ovary (CHO-K1) cells irradiated with (60)Co gamma-radiation.
abstract: The present study was conducted in order to evaluate the effect of Brazilian propolis (AF-08; 5, 10, 15, 30, 50, 100, and 200μg/mL) in protecting CHO-K1 cells against genotoxic and cytotoxic damage and clonogenic death induced by (60)Co gamma-radiation (1.0, 2.0, 4.0, and 6.0Gy). For this purpose, three interlinked endpoints were analyzed: induction of DNA damage by use of the micronucleus (MN) test (genotoxic damage), cell viability by means of the MTS assay, and differential staining (cytotoxic damage) and clonogenic death via the colony-formation test (cytotoxic damage). The MN test revealed that propolis alone (5-100μg/mL) was not genotoxic up to 100μg/mL and that 30μg/mL of propolis reduced the radiation-induced DNA damage (∼56% reduction, p<0.05), exhibiting a radio-protective effect on irradiated CHO-K1 cells. On the other hand, analysis of cytotoxicity showed that a concentration of 50μg/mL presented a significant proliferative effect (p<0.001) when associated with radiation, decreasing the percentage of necrotic cells (p<0.01). No mediated cytotoxic effect was found, but the concentration of 200μg/mL was toxic when analyzed at 24 and 48h via the differential staining technique, but not at 72h after irradiation, analyzed with the MTS assay. Differential staining also showed that necrosis was the main death modality in irradiated cells and that apoptosis was induced only at the toxic concentration of propolis (200μg/mL). Concerning the clonogenic capacity, a concentration of 50μg/mL also exhibited a significant stimulating effect on cell proliferation (p<0.001), in agreement with the data from differential staining. Taken together, these data suggest that the use of propolis AF-08 for the prevention of the adverse effects of ionizing radiation is promising. Nevertheless, additional investigations are necessary for a better understanding of potential applications of propolis to improve human health.
authors: Instituto de Pesquisas Energéticas e Nucleares, Centro de Biotecnologia, IPENCNEN/SP, São Paulo, Brazil, Av. Prof. Lineu Prestes, 2242, CEP 05508-900, Caixa Postal 11049, Cidade Universitária, São Paulo, Brazil. Electronic address: geyz@hotmail.com.
authors: Geyza Spigoti
authors: GS
authors: Santos
authors: Amazon Food K.K. Chiyoda-Ku, Misaki-Cho, 3-1-8-2F, 101-0061 Tokyo, Japan. Electronic address: tsutsumi@amazonfood.co.jp.
authors: Shigetoshi
authors: S
authors: Tsutsumi
authors: Instituto de Pesquisas Energéticas e Nucleares, Centro de Biotecnologia, IPENCNEN/SP, São Paulo, Brazil, Av. Prof. Lineu Prestes, 2242, CEP 05508-900, Caixa Postal 11049, Cidade Universitária, São Paulo, Brazil. Electronic address: dpvieira@ipen.br.
authors: Daniel Perez
authors: DP
authors: Vieira
authors: Instituto de Pesquisas Energéticas e Nucleares, Centro de Biotecnologia, IPENCNEN/SP, São Paulo, Brazil, Av. Prof. Lineu Prestes, 2242, CEP 05508-900, Caixa Postal 11049, Cidade Universitária, São Paulo, Brazil. Electronic address: pbartoli@ipen.br.
authors: Paolo
authors: P
authors: Bartolini
authors: Instituto de Pesquisas Energéticas e Nucleares, Centro de Biotecnologia, IPENCNEN/SP, São Paulo, Brazil, Av. Prof. Lineu Prestes, 2242, CEP 05508-900, Caixa Postal 11049, Cidade Universitária, São Paulo, Brazil. Electronic address: kokazaki@ipen.br.
authors: Kayo
authors: K
authors: Okazaki
mesh_terms: D000818:Animals; D001938:Brazil; D016466:CHO Cells; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003037:Cobalt Radioisotopes; D003114:Colony-Forming Units Assay; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005720:Gamma Rays / Q000009:adverse effects*; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects / Q000528:radiation effects; D011429:Propolis / Q000008:administration & dosage / Q000494:pharmacology*; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D003037:Cobalt Radioisotopes; D011837:Radiation-Protective Agents; D011429:Propolis
keywords: Brazilian propolis; Cytotoxicity; Micronuclei; Radiation; Survival curve