Protección del ácido clorogénico frente a lesiones inducidas por venzo(a)pireno en Saccharomyces cerevisiae / Protection of chlorogenic acid against benzo(a)pyrene-induced lesions in Saccharomyces cerevisiae / Proteção do ácido clorogênico contra lesões induzidas por benzo(a)pireno em Saccharomyces cerevisiae

El objetivo del presente estudio fue analizar el efecto del ácido clorogénico, uno de los compuestos polifenólicos con mayor concentración en la infusión de Ilex paraguariensis, sobre el daño celular y molecular inducido por el benzo(a)pireno. La infusión de Ilex paraguariensis ("mate") es bebida por la mayoría de los habitantes de Argentina, Paraguay, sur de Brasil y Uruguay. La levadura Saccharomyces cerevisiae (cepas SC7K lys2-3; SX46A y SX46Arad14() se utilizó como modelo eucariota. Las células en crecimiento exponencial se expusieron a concentraciones crecientes de benzo(a)pireno y a tratamientos combinados con una concentración de 250 ng/mL de benzo(a)pireno y ácido clorogénico a una concentración igual a la encontrada en la infusión de yerba mate. Luego de los tratamientos se determinaron fracciones de sobrevida, frecuencia mutagénica y roturas de doble cadena de ADN así como la modulación en la expresión de la proteína Rad14 a través de un análisis de Western Blot. Se observó un aumento significativo en las fracciones de sobrevida así como una disminución en la frecuencia mutagénica después de la exposición combinada con benzo(a)pireno y ácido clorogénico en comparación con los tratamientos con benzo(a)pireno como único agente. En la cepa mutante deficiente en la proteína Rad14 se observó un aumento significativo en la sensibilidad a benzo(a)pireno en comparación con la cepa SC7K lys2-3. En los tratamientos combinados de benzo(a)pireno y ácido clorogénico se observó una importante disminución de la letalidad. Con respecto a la determinación de roturas de doble cadena de ADN no se observó fraccionamiento cromosómico a la concentración de benzo(a)pireno utilizada en los experimentos. Los análisis de Western Blot mostraron un aumento en la expresión de la proteína Rad14 en las muestras tratadas con benzo(a)pireno como único agente en comparación con la muestra control. Adicionalmente se observó una disminución en la expresión de la proteína cuando en los tratamientos se utilizaron benzo(a)pireno y ácido clorogénico combinados. Los resultados indican que el ácido clorogénico disminuye significativamente la actividad mutagénica producida por el benzo(a)pireno, la cual no se encuentra relacionada con un incremento en la remoción de las lesiones inducidas por el sistema de reparación por escisión de nucleótidos.

The aim of this study was to analyze the effect of chlorogenic acid, a polyphenolic compound found at high concentrations in Ilex paraguariensis infusions, on cellular and molecular damage induced by benzo(a)pyrene. Ilex paraguariensis infusions ("mate") are consumed by most of the population in Argentina, Paraguay, southern Brazil and Uruguay. Saccharomyces cerevisiae yeast (SC7K lys2-3; SX46A and SX46Arad14( strains) were used as eukaryotic model organisms. Cells in an exponential growth phase were exposed to increasing concentrations of benzo(a)pyrene, as well as combined treatments of benzo(a)pyrene at a concentration of 250 ng/mL and chlorogenic acid at a concentration matching that which is commonly found in mate. Determinations of surviving fraction, mutagenic frequency and double strand DNA breaks induction were performed, along with the assessment of the modulation of the expression of protein Rad14 by Western Blot. A significant increase of surviving fractions and a decrease in mutagenic frequency were observed after exposure to benzo(a)pyrene plus chlorogenic acid, contrary to benzo(a)pyrene alone. A substantial increase in sensitivity to benzo(a)pyrene was observed for the Rad14 protein-deficient mutating strain when compared to the SC7K lys2-3 strain. An important decrease in lethality was observed when combined benzo(a)pyrene and chlorogenic acid treatments were applied. As for the determination of DSBs, no chromosomic fractionation was observed at the benzo(a)pyrene concentration tested in the experiments. Western Blot analysis showed an increase in the expression of protein Rad14 for samples treated with benzo(a)pyrene as a single agent when compared against the control sample. Additionally, the expression of this protein was observed to diminish when combined treatments with benzo(a)pyrene and chlorogenic acid were used. Results obtained indicate that chlorogenic acid significantly decreases the mutagenic activity of benzo(a)pyrene, which is not related to an increase in the removal of lesions induced by nucleotide excision repair system.

O objetivo deste estudo foi analisar o efeito do ácido clorogênico, um dos compostos polifenólicos com maior concentração na infusão de Ilex paraguariensis, sobre o dano celular e molecular induzido pelo benzopireno. A infusão de Ilex paraguariensis ("mate") é consumida pela maioria dos habitantes da Argentina, Paraguai, sul do Brasil e Uruguai. A levedura Saccharomyces cerevisiae (cepas SC7K lys2-3; SX46A e SX46Arad14() foi utilizada como modelo eucariótico. Células em crescimento exponencial foram expostas a concentrações crescentes de benzopireno e tratamentos combinados foram realizados com uma concentração de 250 ng/mL de benzo(a)pireno e ácido clorogênico, igual à encontrada na infusão de erva-mate. Após os tratamentos, foram determinadas as frações de sobrevivência, frequência mutagênica e quebras de fita dupla do DNA, bem como a modulação na expressão da proteína Rad14 por meio de análise de Western Blot. Um aumento significativo nas frações de sobrevivência, bem como uma diminuição na frequência mutagênica foram observados após a exposição combinada de benzo(a)pireno e ácido clorogênico em comparação com tratamentos de agente único de benzo(a)pireno. Um aumento significativo na sensibilidade ao benzo(a)pireno foi observado na cepa mutante deficiente em proteína Rad14 em comparação com a cepa SC7K lys2-3. Nos tratamentos combinados de benzo(a)pireno e ácido clorogênico, observou-se uma diminuição significativa na letalidade. Com relação à determinação das quebras de fita dupla de DNA, não foi observado fracionamento cromossômico na concentração de benzo(a)pireno utilizada nos experimentos. A partir da análise de Western Blot, observou-se um aumento na expressão da proteína Rad14 nas amostras tratadas com benzo(a)pireno como agente único em relação à amostra controle. Além disso, uma diminuição na expressão da proteína foi observada quando combinados de benzo(a)pireno e ácido clorogênico foram usados ​​nos tratamentos. Os resultados obtidos neste trabalho indicam que o ácido clorogênico diminui significativamente a atividade mutagênica produzida pelo benzo(a)pireno, a qual não está relacionada a um aumento na remoção de lesões induzidas pelo sistema de reparo por excisão de nucleotídeos.

Efecto radioprotector del ácido tánico y vinos de la var vitis vinífera L. cv tannat en Saccharomyces cerevisiae / Radioprotective effect of tannic acid and wines of the vitis vinifera L. cv tannat on Saccharomyces cerevisiae / Proteção contra radiação por vinho tinto var tannat e ácido tanico em Saccharomyces cerevisiae

El vino tinto variedad Vitis vinifera L. cv Tannat en los últimos años ha tomado relevancia por su alta concentración de polifenoles, esto le podría significar un rol protector sobre el genoma disminuyendo la formación de lesiones oxidativas. Los efectos a nivel celular de las radiaciones ionizantes en blancos como el ADN, componentes de cascadas de transducción de señales, resultan en lesiones letales, mutagénicas y recombinogénicas y en retardos en el ciclo celular. Se utilizó como modelo eucariota poblaciones de Saccharomyces cerevisiae en fase exponencial expuestas a radiación gamma (200 Gy) en presencia, o ausencia, de vino Tannat (10 % v/v) o de ácido tánico (60 µg/mL). Se estimaron las probabilidades de sobrevida y frecuencia mutagénica en distintas condiciones. Las muestras celulares expuestas a radiación ionizante presentaron una fracción de sobrevida de 0.21 ± 0.02 mientras que en las muestras irradiadas en presencia de vino Tannat o de ácido tánico la fracción de sobrevida fue de 0.33 ± 0.03 y 0.30 ± 0.03 respectivamente. Se observó en las poblaciones irradiadas un aumento significativo de la probabilidad de mutagénesis. En el caso de los tratamientos combinados se observó que la frecuencia mutagénica fue significativamente menor (gamma Tannat: 33%, gamma ácido tánico: 45% ). Estos resultados preliminares podrían indicar radioprotección moderada por parte de los compuestos estudiados, efecto que podría explicarse por las interacciones redox del ácido tánico y polifenoles contenidos en el vino con los radicales libres formados por las radiaciones ionizantes, además de la activación de vías de reparación genómica.

The red wine variety Vitis vinifera L. cv Tannat in recent years has gained relevance due to its high concentration of polyphenols, this could mean a protective role on the genome, reducing the formation of oxidative lesions. The effects at the cellular level of ionizing radiation on targets such as DNA, components of signal transduction cascades, result in lethal, mutagenic and recombinogenic lesions and delays in the cell cycle. Exponential phase populations of Saccharomyces cerevisiae exposed to gamma radiation (200 Gy) in the presence or absence of Tannat wine (10% v / v) or tannic acid (60 µg / ml) were used as a eukaryotic model. The probabilities of survival and mutagenic frequency in different conditions were estimated. Cellular samples exposed to ionizing radiation presented a survival fraction of 0.21 ± 0.02, while in samples irradiated in the presence of Tannat wine or tannic acid, the survival fraction was 0.33 ± 0.03 and 0.30 ± 0.03 respectively. A significant increase in the probability of mutagenesis was observed in irradiated populations. In the case of the combined treatments, it was observed that the mutagenic frequency was significantly lower (Tannat gamma: 33%, Tannic acid gamma: 45%). These preliminary results could indicate moderate radioprotection by the compounds studied, an effect that could be explained by the redox interactions of tannic acid and polyphenols contained in wine with the free radicals formed by ionizing radiation, in addition to the activation of genomic repair pathways.

A variedade de vinho tinto Vitis vinifera L. cv Tannat nos últimos anos tem ganhado relevância devido à sua alta concentração de polifenóis, o que pode significar um papel protetor do genoma, reduzindo a formação de lesões oxidativas. Os efeitos no nível celular da radiação ionizante em alvos como o DNA, componentes de cascatas de transdução de sinal, resultam em lesões letais, mutagênicas e recombinogênicas e atrasos no ciclo celular. Populações de fase exponencial de Saccharomyces cerevisiae expostas à radiação gama (200 Gy) na presença ou ausência de vinho Tannat (10% v / v) ou ácido tânico (60 µg / ml) foram utilizadas como modelo eucariótico. Foram estimadas as probabilidades de sobrevivência e frequência mutagênica em diferentes condições. As amostras celulares expostas à radiação ionizante apresentaram uma fração de sobrevivência de 0,21 ± 0,02, enquanto nas amostras irradiadas na presença de vinho Tannat ou ácido tânico, a fração de sobrevivência foi de 0,33 ± 0,03 e 0,30 ± 0,03, respectivamente. Um aumento significativo na probabilidade de mutagênese foi observado nas populações irradiadas. No caso dos tratamentos combinados, observou-se que a frequência mutagênica foi significativamente menor (Tannat gama: 33%, ácido tânico gama: 45%). Esses resultados preliminares podem indicar radioproteção moderada pelos compostos estudados, efeito que pode ser explicado pelas interações redox do ácido tânico e polifenóis contidos no vinho com os radicais livres formados pela radiação ionizante, além da ativação de vias de reparo genômico.

Suppression of doxorubicin apoptotic, histopathologic, mutagenic and oxidative stress effects in male mice bone marrow and testis tissues by aqueous rosemary leaves extract

In the present set of investigations, the anti-mutagenic and anti-cytotoxic effects of aqueous rosemary leaves extract [RE] beside the dose dependency of these effects on male mice bone marrow and germ cells have been evaluated using in vivo cytogenetic, histopathologic and apoptotic assays, as well as biochemical analysis. Doxorubicin [DXR], a well-known mutagen and cytotoxic agent, was given at a single dose of 25 mg/kg b. wt. intraperitoneally at the fifteenth day. 25, 125, 250 and 375 mg/kg b. wt. of RE were given through oral intubation once a day/three days for 15 days prior to DXR administration. The animals of the positive control group [DXR alone] showed significant increase in the mutagenic effect in bone marrow cells, histological damage, incidence of apoptotic cells [TUNEL-positive cells], level of lipid peroxidation and activity of superoxide dismutase in testis. Though, the activities of the other antioxidant enzymes such as glutathione peroxidase, catalase and glutathione reduced form beside the serum level of testosterone and the rate of primary spermatocytes' transformation to spermatids were significantly declined [P < 0.001]. The ratio of dismutase to glutathione peroxidase and/or catalase was significantly elevated. Pretreatment with each dose of RE showed significant reduction in these frequency of chromosomal aberrations and mitotic index of bone marrow cells and the level of peroxidation, the ratio of SOD/ GPX or CAT, the histological damage and the incidence of apoptotic cells in testes. Also, it caused increase in the levels of some antioxidant enzymes [GSH, CAT and GPX], the level of testosterone and returned the semineferous tubular cell populations' ratio to the control distribution.The protective efficacy of the RE was much pronounced following pretreatment with 125 mg/kg b. wt

Chronic effects of mustard gas on liver parenchyma in rat

Sulfur mustard [bis [2-chloroethyl] sulfide] is a strong alkylating agent with known mutagenic and suspected carcinogenic properties. Eighty NMARI male rats, 3 months old, were divided into eight groups [10 in each groups], were injected with 2.5, 5 and 10 mg /kg sulfur mustard plus Tyrods buffer. Rats were kept under optimal hygienic condition, temperature 25 C, relative humidity 40 to 45% and light provided for a 12-h day/12-h night cycle. They were given water and rodent pellets. After 2 and 8 weeks rats were killed. The samples were fixed in formaldehyde solution [%10], were stained with H and E and PAS and were studied with light microscope. Increased blood cells in hepatic sinusoids, disappearance borders of liver lobules, irregulation of hepatic cord, apoptotic appearance of cells in lobule, and these signs were seen in 2/5 mg/kg [8 weeks], 5mg/kg [2 and 8 weeks] and 10 mg /kg [2 and 8 weeks] groups. Glycogen decreased in 5mg/kg [8 weeks] and 10 mg/kg [2 and 8 weeks] groups. All of changes were dependent on dosage and time duration.

protective role of folic acid on the mutagenicity induced by sodium sulfite in different tissues of male mice

The genotoxic effect of sodium sulfite [Na2SO2] one of the oldest food additives was evaluated. Sulfur dioxide [SO2] is liberated in the body after administering Na2SO3 and it is the effective chemical. The induction of chromosome aberrations and sister-chromatid exchange in bone-marrow, chromosome aberrations and sperm abnormalities in germ cells of the mouse was investigated. Oral treatment by gavage with the doses 125, 250 and 625 mg/kg b. wt. [1/20, 1/10 and 1/4 LD50] for 1, 7 and 14 days increased chromosome aberrations in somatic and germ cells in a dose- and time-dependent manner. The same tested doses induced a significant increase in the frequency of SCE's and sperm abnormalities by increasing the dose of treatment. In all experiments mitomycin C induced much higher effect. Administration of folicacid [FA] at a dose of 10 mg/kg b. wt. slightly minimized the genotoxic effect of SO2 in all experiments examined. The results have confirmed that the food additive sodium sulfite is a clastogenic and genotoxic agent and FA is capable of reducing this damage

RAPD analysis of herbicide-resistant Brasilian rice lines produced via mutagenesis

Over the last two decades, mutational techniques have become one of the most important tools available to progressive rice- breeding programs. In a mutation-breeding program initiated in 1999 at the Instituto Agronômico of Campinas, SP, Brazil, a rice line, IAC103, was selected for mutational studies with gamma radiation and ethyl methyl sulfonate mutagenesis, with the aim of developing a herbicide-resistant crop. After mutagenesis, surviving plants were exposed to glufosinate to check for herbicide resistance, which was examined up to the second generation. A detailed RAPD analysis was made of the resistant plants. Eighty Operon technology primers were tested and 10 were selected for a detailed study of RAPD markers that could tag herbicide resistance genes. Resistant and susceptible lines produced variation in the RAPD patterns and certain bands were found only in certain lines. These results suggest genetic ligation that will be confirmed through a genetic segregation study

Efficiency of Coleus aromaticus extract in modifying cyclophosphamide and mitomycin-C induced clastogenicity in mouse bone marrow cells.

The anticlastogenic potency of the ethanolic extract of a medicinal plant, C. aromaticus was investigated by taking bone marrow chromosomal aberration assay and micronucleus (MN) test as the test parameters. Swiss albino mice were fed orally with different doses (10,15, 25, 50 and 100 mg/kg body weight) of ethanolic extract for 7 days and on the 7th day, two doses each of anticancer drugs cyclophosphamide (CP; 25 and 50 mg/kg body weight) and mitomycin-C (MMC; 4 and 8 mg/kg body weight) were injected, ip, to different groups of animals. Bone marrow MN preparations were made at 24 and 48 hr time intervals. Coleus extract reduced CP and MMC induced MN and lower doses of the extract were found to be more effective than higher doses. The effective doses of extract in MN test were selected to study the anticlastogenic effects against CP (25 and 50 mg/kg body weight) and MMC (2 and 4 mg/kg body weight) induced chromosomal aberrations. The results indicate the protective effect of C. aromaticus against CP and MMC induced cytogenetic damage.

Clastogenic effects of dietary supplement--Spirulina alga, and some medicinal plant products from Boswellia serrata, Withania somnifera on mice.

Pretreatment of aqueous extracts of Zyrulina (Spirulina), Aswagandha (Withania) and Nopane (Boswellia) on colchicine induced chromosome damage showed weakness of clastogenic activity in Swiss albino mice. None of the treatments increased significantly the number of chromosome aberrations.

Obtención de mutantes espontáneas de Clostridium acetobutylicum resistentes al butanol / Obtention of spontaneous mutant of Clostridium acetobutylicum of butanol resistant

En este trabajo reporta la obtención de mutantes espontáneas de Clostridium acetobutylicum DSM1732 resistente a altas concentraciones de butanol (25 g/l), que produce 29.41 g/l de solventes totales, con un rendimiento de sustrato en solventes (Ypis) de 0.59 g de solventes totales por g de sustrato consumido y una productividad de 0.196 g de sol. tot./L*h en medio de cultivo "industrial" a base de melaza. El mutante denominado Clostridium acetobutylicum DSM11732 R se obtuvo mediante exposición a concentraciones crecientes de butanol. También se demostró que en realidad es un grupo de mutantes resistentes al butanol que producen diferentes niveles de solventes totales. El grupo esta conformado por nueve mutantes denominados Clostridium acetobutylicum IBUN I, II, III, IV, V, VI, VII, VII y IX las cuales fueron evaluadas en el medio "industrial" a base de melaza. Las mutantes individualmente producen entre 6 y 18 g/l de solventes totales, con rendimientos (Ypis) entre 0,2 y 0,5 y productividades entre 0.09 y 0.27g de solv. tot./l*h. El estudio de los diferentes parámetros de la fermentación acetobutílica desarrollada por los nueve mutantes se ajusta al mdelo de la fermentación acetobutílica (ABE) en relación al consumo de sustrato, la reasimilación de los ácidos, la velocidad específica de crecimiento (µ) y la producción de solventes...

Antimutagenic activity of plumbagin in Ames Salmonella typhimurium test.

This paper reports the antimutagenic activity of plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone) against certain known chemical mutagens in a standard mutagenicity test system of Ames using S. typhimurium strains. Plumbagin by itself did not show any mutagenic effect, whereas it reduced significantly the mutagenic effect of 4-nitrophenylene diammine, phenyl hydrazine and sodium azide in test strains of S. typhimurium, suggesting that plumbagin possessed antimutagenic activity.