Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants

http://www.dietcan.net/docs/Polifenoles%20en%20alimentos%20y%20biodisponibilidad.pdf

Polyphenols: food sources and bioavailability

Oxidative Stress, Inflammation, and Cancer: How Are They Linked?

Beckman, Kenneth B., and Bruce N. Ames. The Free Radical Theory of Aging Matures. Physiol. Rev. 78: 547–581, 1998. — The free radical theory of aging, conceived in 1956, has turned 40 and is rapidl...

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The Free Radical Theory of Aging Matures

Bioavailability and bioefficacy of polyphenols in humans. I. Review of 97 bioavailability studies

It is increasingly proposed that reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a key role in human cancer development [1–6], especially as evidence is growing that antioxidants may prevent or delay the onset of some types of cancer (reviewed in [7,8]). ROS is a collective term often used by biologists to include oxygen radicals [superoxide (O # J−), hydroxyl (OHJ), peroxyl (RO # J) and alkoxyl (ROJ)] and certain nonradicals that are either oxidizing agents and}or are easily converted into radicals, such as HOCl, ozone (O $ ), peroxynitrite (ONOO−), singlet oxygen ("O # ) and H # O # . RNS is a similar collective term that includes nitric oxide radical (NOJ), ONOO−, nitrogen dioxide radical (NO # J), other oxides of nitrogen and products arising when NOJ reacts with O # J−, ROJ and RO # J. ‘Reactive ’ is not always an appropriate term; H # O # , NOJ and O # J− react quickly with very few molecules, whereas OHJ reacts quickly with almost anything. RO # J, ROJ, HOCl, NO # J, ONOO− and O $ have intermediate reactivities. ROS and RNS have been shown to possess many characteristics of carcinogens [4] (Figure 1). Mutagenesis by ROS}RNS could contribute to the initiation of cancer, in addition to being important in the promotion and progression phases. For example, ROS}RNS can have the following effects. (1) Cause structural alterations in DNA, e.g. base pair mutations, rearrangements, deletions, insertions and sequence amplification. OHJ is especially damaging, but "O # , RO # J, ROJ, HNO # , O $ , ONOO− and the decomposition products of ONOO− are also effective [9–13]. ROS can produce gross chromosomal alterations in addition to point mutations and thus could be involved in the inactivation or loss of the second wild-type allele of a mutated proto-oncogene or tumour-suppressor gene that can occur during tumour promotion and progression, allowing expression of the mutated phenotype [4]. (2) Affect cytoplasmic and nuclear signal transduction pathways [14,15]. For example, H # O # (which crosses cell and organelle membranes easily) can lead to displacement of the inhibitory subunit from the cytoplasmic transcription factor nuclear factor κB, allowing the activated factor to migrate to the nucleus [14]. Nitration of tyrosine residues by ONOO− may block phosphorylation. (3) Modulate the activity of the proteins and genes that respond to stress and which act to regulate the genes that are related to cell proliferation, differentiation and apoptosis [4,14–17]. For example, H # O # can stimulate transcription of c-jun

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Damage to DNA by reactive oxygen and nitrogen species: role in inflammatory disease and progression to cancer.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/0014-5793%2895%2900764-Z

Nitric oxide and oxygen radicals: a question of balance

The soy isoflavones, daidzein and genistein, and the lignans, matairesinol and secoisolariciresinol, are phytoestrogens metabolized extensively by the intestinal microflora Considerable important evidence is already available that shows extensive interindividual variation in isoflavone metabolism, and we have investigated the extent of this variation in a crossover study of a soy-containing food low or high in isoflavones (each treatment period lasted for 17 days, and the 2 treatment periods were separated by a 25-day washout period) in 24 healthy subjects [19 women and 5 men, mean age 30 yr, range 19-40, mean body mass index 225 +/- 35 (SD) kg/m2] There was a 16-fold variation in total isoflavonoid excretion in urine after the high-isoflavone treatment period The variation in urinary equol excretion was greatest (664-fold), and subjects fell into two groups: poor equol excretors and good equol excretors (36%) A significant negative correlation was found between the proportion of energy from fat in the habitual diet and urinary equol excretion (r = -055; p = 0012) Good equol excretors consumed less fat as percentage of energy than poor excretors (26 +/- 23% compared with 35 +/- 16%, p < 001) and more carbohydrate as percentage of energy than poor excretors (55 +/- 29% compared with 47 +/- 17%, p < 005) Interindividual variation in the urinary excretion of O-desmethyl-angolensin (O-DMA) was also apparent (76-fold after the high-isoflavone treatment period), but there was no relationship between equol excretion and O-DMA excretion Enterolactone was the major lignan metabolite in urine and plasma but showed less interindividual variation than equol and O-DMA It is suggested that the dietary fat intake decreases the capacity of gut microbial flora to synthesize equol

Interindividual variation in metabolism of soy isoflavones and lignans: influence of habitual diet on equol production by the gut microflora.

Isoflavone phytoestrogens consumed in soy decrease F2-isoprostane concentrations and increase resistance of low-density lipoprotein to oxidation in humans

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/0014-5793%2893%2981809-E

Vitamin D is a membrane antioxidant. Ability to inhibit iron-dependent lipid peroxidation in liposomes compared to cholesterol, ergosterol and tamoxifen and relevance to anticancer action.

Helen Wiseman

Papers

Damage to DNA by reactive oxygen and nitrogen species: role in inflammatory disease and progression to cancer.

Nitric oxide and oxygen radicals: a question of balance

Interindividual variation in metabolism of soy isoflavones and lignans: influence of habitual diet on equol production by the gut microflora.

Isoflavone phytoestrogens consumed in soy decrease F2-isoprostane concentrations and increase resistance of low-density lipoprotein to oxidation in humans

Vitamin D is a membrane antioxidant. Ability to inhibit iron-dependent lipid peroxidation in liposomes compared to cholesterol, ergosterol and tamoxifen and relevance to anticancer action.