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Therapeutic Properties of Fermented Foods and Beverages
Published in Megh R. Goyal, Preeti Birwal, Durgesh Nandini Chauhan, Herbs, Spices, and Medicinal Plants for Human Gastrointestinal Disorders, 2023
The process of oxidation produces free radicals that damage the cell membrane, cell structures including cellular proteins, lipids and DNA. The free radicals can be neutralized to some extent by cellular phospholipids, further production of free radicals’ overloads in the cells and causes certain diseases including cardiovascular disease, liver disease, oral cancer, esophageal cancer, gastric cancer and bowel cancer. Oxidation is accelerated by stress, cigarette smoking, alcohol consumption and exposure to pollution. The enzyme system, such as, catalase, glutathione peroxidase, superoxide dismutase and non-enzymatic antioxidants comprising of vitamin C, tocopherols, carotenoids and phenolic compounds help to prevent cells from oxidative damage.57
Trigonella foenum-graecum L.
Published in Dilip Ghosh, Prasad Thakurdesai, Fenugreek, 2022
G. Sindhu, Chithra K. Pushpan, A. Helen
Reactive oxygen and nitrogen species like hydroxyl radical (.OH), superoxide (O2.-) and hydrogen peroxide (H2O2), nitric oxide (NO.), peroxynitrite (ONOO-) are some of the powerful free radicals involved in causing damage to biological molecules (Sergio Di Meo et al., 2016) causing oxidative modification and even resulting in complete damage of cells. Antioxidants scavenge the radicals, protecting the cells from oxidation and therefore an increased intake of antioxidants would reduce the oxidative damage caused by the free radicals (Xu et al., 2017). Antioxidants are present in a wide variety of fruits, vegetables, and medicinal plants. The main bioactive compounds in plants studied for their antioxidant properties in plants are polyphenols that include flavonoids, anthocyanins, etc., carotenoids like xanthophyll and carotenes, and some vitamins like vitamin C. These compounds have also been shown to have anti-inflammatory, anti-aging, anti-microbial, and anti-cancer activities (Deng et al., 2012; Li et al., 2014; Xu et al., 2017).
Herbal Food Product Development and Characteristics
Published in Anil K. Sharma, Raj K. Keservani, Surya Prakash Gautam, Herbal Product Development, 2020
Phenolic compounds of herbs are a good choice for the synthetic antimicrobial agents that are used in food products. Various phenolic compounds present in herbs have been reported to inhibit the growth of pathogens, namely, Salmonella enteritidis, Listeria monocytogenes, Staphylococcus aureus, and fungi. Herbs are good sources of antioxidants and are considered safe. Antioxidants help in delaying the oxidation of molecules by inhibiting the initiation or propagation of oxidizing chain reactions by free radicals and may reduce oxidative damage to the human body (Namiki, 1990). Various functional properties of herbs are tabulated in Figure 2.1.
Chemistry of ROS-mediated oxidation to the guanine base in DNA and its biological consequences
Published in International Journal of Radiation Biology, 2022
Aaron M. Fleming, Cynthia J. Burrows
Ionizing radiation (IR) is so termed because the photons or particles are of sufficient energy to eject electrons from the substrate creating ions from neutral components. In chemistry, any process that leads to loss of electrons is considered an oxidation. Ionization of water leads to hydroxyl radical formation plus an electron; the HO• so formed can add to any of the heterocyclic bases of DNA, or it can abstract a hydrogen atom (H•) from the base or the ribose (Cadet et al. 2012; Steenken 1989; Pogozelski and Tullius 1998). IR can also directly impact DNA bases by loss of an electron and a proton generating, for example, guanine and adenine radicals, formally (G-H)• and (A-H)• (Greenberg 2021). The chemistry of guanine and adenine radicals is complex and depends upon the surrounding sequence and the presence of oxidants including O2 and reductants such as glutathione, ascorbate and urate. Many reviews detail these chemical pathways, a portion of which is shown in Figure 1 (Cadet et al. 2014; Greenberg 2021).
Dietary antioxidants associated with slower progression of parkinsonian signs in older adults
Published in Nutritional Neuroscience, 2022
Puja Agarwal, Yamin Wang, Aron S. Buchman, Thomas M. Holland, David A. Bennett, Martha C. Morris
The mechanism underlying the associations between antioxidant nutrients and parkinsonian signs presented in this paper is unclear. Carotenoids, vitamin E, and vitamin C are key dietary antioxidant nutrients that may reduce oxidation and the production of reactive oxygen species. High plasma levels of these nutrients are also associated with reduced inflammatory markers [29]. Oxidative stress and inflammation are two main mechanisms for neurodegenerative disorders in older adults [30]. Various in-vitro studies have indicated that carotenoids may decrease oxidative stress and inflammation via different direct and indirect pathways [31]. Animal models suggest vitamin E reduces oxidative stress in the brain [32], restores synaptic plasticity [9] and has a neuroprotective effect in aging rats [33]. Similarly, vitamin C is reported to scavenge free radicals, prevent membrane lipid peroxidation in the brain, [34] and modulate glutamatergic neurotransmission [35,36] in various experimental models. Recent work suggests that subclinical mixed brain pathologies such as Alzheimer’s disease, Lewy body dementia, and cerebrovascular disease pathologies may contribute to the presence of severe parkinsonian signs without the overt neurological disease in older adults [37]. Thus, a healthy diet rich in antioxidant nutrients with free radical scavenging properties may play an important role in preventing parkinsonian signs and its progression in old age.
Antioxidant and cytoprotective properties of loganic acid isolated from seeds of Strychnos potatorum L. against heavy metal induced toxicity in PBMC model
Published in Drug and Chemical Toxicology, 2022
Alagarsamy Abirami, Simran Sinsinwar, Perumal Rajalakshmi, Pemaiah Brindha, Yamajala B. R. D. Rajesh, Vellingiri Vadivel
Antioxidants are substances that scavenge free radicals and prevent the oxidation of other compounds. DPPH assay is based on the reduction of purple colored DPPH to non-radical form (DPPH-H) with yellow color. DPPH has maximum absorbance at 515 nm, and it might decrease in presence of antioxidant compound, which involved in the transformation of radical DPPH to DPPH-H. Loganic acid has antioxidant activity with IC50 value of 149 µg/mL (Figure 4(A)). Similarly, DPPH radical scavenging activity of iridoid glucosidic compounds (Tiwari et al. 2012) and eugenol with IC-50 value of 242 µg/ml was reported (Mahapatra and Roy 2014). DPPH radical activity of terpenoid compounds such as carnosic acid and carnosol (Hopia et al. 1996), carvacrol, thymol and gingerol (Aeschbach et al. 1994, Schwarz et al. 1996), linalool (Seol et al. 2016), alpha-pinene, limonene, myrcene, and nerol (Wang et al. 2019) have already been reported and their ability to donate protons to reduce the DPPH into DPPH-H has been experimentally proved. In the case of loganic acid (a monoterpenoid compound), the antioxidant activity in terms of DPPH radical scavenging activity was demonstrated for the first time in our study. Even though the proton donating ability of loganic acid was not measured directly, all the research papers explaining the bleaching of DPPH color is due to proton donating ability of the antioxidants and hence, proton donating capacity was proposed as the antioxidant mechanism of loganic acid.