Mechanisms of Action of Antioxidants as Exemplified in Vegetables, Tomatoes and Tea

Weisburger, John H.

doi:10.1016/s0278-6915(99)00086-1

Cited by 199 publications

(122 citation statements)

References 37 publications

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“…Vegetables and fruits are rich sources of micronutrients, including vitamins, minerals, dietary fibers and many other classes of biologically active compounds. Free radicals formed endogenously as a result of normal oxidative metabolic reactions can form DNA adducts, which can accumulate and result in gene mutations 36 ; and antioxidants present in fruits and vegetables could reduce DNA damage by quenching exogenous or endogenously produced free radicals. In addition, fruits and vegetables contain substances that can modulate enzymes that both activate and detoxify chemical carcinogens.…”

Section: Discussionmentioning

confidence: 99%

Dietary and other risk factors in women having fibrocystic breast conditions with and without concurrent breast cancer: A nested case‐control study in Shanghai, China

Ray

Lampe

et al. 2005

Intl Journal of Cancer

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Risk of breast cancer is increased in women with proliferative benign breast conditions. Most of these conditions, however, do not progress to breast cancer. The purpose of our study was to identify factors possibly associated with this progression. Women with proliferative fibrocystic breast conditions alone (214), and women with proliferative fibrocystic breast conditions and concurrent breast cancer (130), were compared to each other, and each of these groups of women were also compared to 1,070 controls; and 176 women with non-proliferative benign breast conditions alone, and 155 also with breast cancer, were similarly compared. All study subjects were selected from a cohort of women enrolled in a trial of breast self-examination in Shanghai. Women were interviewed to ascertain information on suspected risk factors for breast cancer and dietary habits. Conditional logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI). Increased risks of both proliferative fibrocystic breast conditions alone, and with breast cancer, were associated with low parity, a prior benign breast lump and breast cancer in a first-degree relative. Decreasing trends in the risk of both conditions with increasing intake of fruits and vegetables were observed. No factors were significantly associated with risk of breast cancer relative to risk of proliferative changes. Similar, but in some instances weaker, associations were observed for non-proliferative fibrocystic conditions with and without breast cancer. The possible risk or protective factors that were observed in our study most likely alter the risk of breast cancer at an early stage in the carcinogenic process, and probably do not alter risk of progression from proliferative fibrocystic breast conditions to breast cancer. ' 2005 Wiley-Liss, Inc.Key words: breast cancer; fibrocystic breast conditions; risk factors; diet; fruits; vegetables Women who have undergone a breast biopsy for benign breast disease are at increased risk of breast cancer. 1 Although nonproliferative breast conditions do not seem to be associated with increased risk of breast cancer, proliferative fibrocystic breast conditions without and with atypia have been associated with 2-fold and 4-fold increased risks of breast cancer, respectively. 2-8 Most women who are diagnosed with proliferative fibrocystic breast conditions do not develop breast cancer, however, suggesting the presence of risk factors necessary for progression.Breast cancer presumably results when a cell first undergoes an initiating genetic alteration, and then either this cell or one of its daughter cells, which inherits that initiating genetic damage is transformed into a cell with malignant characteristics by undergoing one or more subsequent events. In this scenario, proliferative activity may play an important role by increasing the expansion of initiated cells and the likelihood that one will undergo subsequent events ultimately leading to transformation to a malignant phenotype. 9,10 The morp...

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Section: Discussionmentioning

confidence: 99%

Dietary and other risk factors in women having fibrocystic breast conditions with and without concurrent breast cancer: A nested case‐control study in Shanghai, China

Ray

Lampe

et al. 2005

Intl Journal of Cancer

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“…O stress oxidativo tem sido associado ao desenvolvimento de muitas doenças crônicas e degenerativas, incluindo o câncer, doenças cardíacas, doenças degenerativas como Alzheimer, bem como está envolvido no processo de envelhecimento 4,5,12,14,22,35 . O balanço entre o stress oxidativo e as funções antioxidantes dos organismos vivos parece ter um papel na carcinogênese 43,44 . Estudos clínicos e epidemiológicos têm mostrado evidências de que antioxidantes fenólicos de cereais, frutas e vegetais são os principais fatores que contribuem para a baixa e significativa redução da incidência de doenças crônicas e degenerativas encontradas em populações cujas dietas são altas na ingestão desses alimentos 36 .…”

Section: Introductionunclassified

Atividade antioxidante de frutas do cerrado

Roesler¹,

Malta²,

Carrasco³

et al. 2007

Ciênc. Tecnol. Aliment.

350

107

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53 ResumoAnnona crassiflora (araticum), Solanum lycocarpum (lobeira), Eugenia dysenterica (cagaita), Caryocar brasilense (pequi) e Swartzia langsdorfii (banha de galinha) são frutas do bioma cerrado, conhecidas e consumidas principalmente por populações nativas dessa região. Nesse estudo, as diferentes frações dos frutos acima descritos (polpa, semente e casca) foram avaliadas por meio de extratos aquosos e etanólicos. Alguns extratos mostraram altíssimos conteúdos de compostos fenólicos e foram escolhidos para avaliação do potencial em seqüestrar radicais livres por meio do modelo 2,2 difenil-1-picril hidrazil (DPPH). Os melhores resultados foram: extrato aquoso e etanólico de casca de pequi (IC 50 igual a 9,44 e 17,98 mg.mL -1 respectivamente), extrato etanólico de sementes de cagaita (IC 50 igual a 14,15 mg.mL -1 ), extrato etanólico de sementes e casca de araticum (IC 50 igual a 30,97 e 49,18 mg.mL -1 , respectivamente). Este é o primeiro estudo que avalia o potencial em seqüestrar radicais livres de frações de frutas do cerrado. Os resultados indicam que os extratos possuem grande potencial antioxidante e estudos adicionais são necessários para avaliar essa propriedade dos extratos como uma aplicação sustentável dos recursos do cerrado nos setores farmacêuticos, cosméticos e nutricionais. Palavras-chave: frutas tropicais; cerrado; atividade antioxidante; DPPH; fenóis. AbstractAnnona crassiflora (araticum), Solanum lycocarpum (lobeira), Eugenia dysenterica (cagaita), Caryocar brasilense (pequi) and Swartzia langsdorfii (banha de galinha) are tropical fruits consumed mainly by native people in the Brazilian Cerrado (second biggest biome of Brazil). In this study, pulp, seed and peel of the fruits were extracted using ethanol and water. Some of the extracts showed a high content of total phenols and were screened for their potential as antioxidants using the in vitro model 2,2-diphenyl-1-picryl hydrazyl (DPPH). The best results were found for aqueous and ethanolic extracts of pequi peel (IC 50 of 9,44 and 17,98 mg.mL -1 respectively), etanolic extract of cagaita seeds (IC 50 of 14,15 mg.mL -1 ), etanolic extract of araticum seeds and peel (IC 50 of 30,97 and 49,18 mg.mL -1 respectively). This is the first report on the antioxidant properties of the extracts of cerrado fruit fractions. Owing to these properties, studies can be further extended to use them for possible applications as natural antioxidant for cosmetics, supplements and functional ingredients for food products as well as being able to represent a sustainable application of the natural sources in the Brazilian bioma cerrado. Keywords: tropical fruits; cerrado; antioxidant activity; DPPH; phenols. Atividade antioxidante de frutas do cerrado Antioxidant activity of cerrado fruitsRoberta ROESLER 1 *, Luciana Gomes MALTA 1 , Luciana Cristina CARRASCO 1 , Roseane Barata HOLANDA 1 , Clélia Alves Socorro SOUSA 2 , Glaucia Maria PASTORE 1 IntroduçãoA oxidação é um processo metabólico que leva à produção de energia necessária para as atividades essenciais d...

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“…They can harm vitally important structures, such as cell membranes, destroying deoxyribonucleic acid (DNA) that is an essential core component of every cell and damaging the respiratory enzymes and genetic material, thus creating the preconditions for the emergence of degenerative and malignant diseases [5,6,7,8].…”

Section: Introductionmentioning

confidence: 99%

“…Antioxidants of both endogenous and exogenous sources have the ability to donate electrons and are effective in mitigating the damaging effects of ROS on cellular components [12]. Honey is a complex mixture of more than seventy different compounds present in varying proportions [13,14].…”

Section: Introductionmentioning

confidence: 99%