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An Overview of Molecular Nutrition
Published in Nicole M. Farmer, Andres Victor Ardisson Korat, Cooking for Health and Disease Prevention, 2022
Vincent W. Li, Catherine Ward, Delaney K. Schurr
In relation to food and dietary intake and health, carotenoids, phenolics, and organosulfur compounds likely represent the most widely investigated phytochemicals. Among the phenolic phytochemicals, flavonoids are divided into several groups (Figure 3.5), among which flavonols, flavones, and flavanols are the most common in foods that are related to health. In fact, flavonols are the most ubiquitous flavonoids in foods. Quercetin is one of the major flavonoids found in foods. Flavonol biosynthesis is stimulated by light within the plant. Thus, fruit often contains more flavonols in the outer (skin) or aerial tissues (leaves). For example, cherry tomatoes have higher flavonol content than standard tomatoes because they have different proportion of skin to whole fruit. Flavones are less common than flavonols in fruit and vegetables. Most flavones in foods are luteolin and apigenin. Like flavonols, the skin of fruits and vegetables contain the largest amounts of flavones (Figure 3.6).
Free Radicals and Antioxidants
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Flavonols are derivatives of flavones with a hydroxyl (OH) group at C3 and include quercetin, kaempferol, myricetin, galangin, fisetin, robinin, rhamnetin, spirenoside, and rutin. They are mainly found in broccoli, grapes, olive, olive oil, honey, lesser galangal, onion, red wine, berries, grapefruit, walnut, caper, fennel, Ginkgo biloba leaves, and nuts. Flavonols are the most widespread compounds in the human diet. Some of these compounds are more predominant than others in each plant type. For example, galangin is mainly found in the rhizome of lesser galangal and not in broccoli, olive, walnut, or grapefruit, while quercetin levels are high in caper, fennel, and onion, low in broccoli and olive fruit, and absent in galangal rhizome.
Chemopreventive Agents
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
However, it is important to appreciate the magnitude of the challenge in trying to understand the details of how a particular chemopreventive agent or its close analogues may inhibit the transition of a healthy cell into a tumor cell, or the growth and development of a small tumor once it is established. To illustrate this challenge, it is instructive to look at the literature relating to the flavonols, a group of reported chemopreventive compounds containing the 3-hydroxy-2-phenylchromen-4-one core, key members of which included quercetin, kaempferol, casticin, and galangin (Figure 12.2). Although all flavonols contain the 3-hydroxyflavone backbone, family members vary depending on the position of phenolic -OH groups. Flavonols of this type are found in a variety of vegetables such as onions, tomatoes, and broccoli, with an estimated intake in Western diets averaging 20–50 mg per day, and are also present in some fruits. Chemical structures of the parent flavonol structure, and the family members quercetin, kaempferol, casticin, and galangin.
Flavonoid-rich fraction of Lasianthera africana leaves alleviates hepatotoxicity induced by carbon tetrachloride in Wistar rats
Published in Drug and Chemical Toxicology, 2022
Daniel Emmanuel Ekpo, Parker Elijah Joshua, Arome Solomon Odiba, Okwesilieze Fred Chiletugo Nwodo
Although liver injury is a major cause of death worldwide, therapeutic interventions targeted at protecting the hepatocytes from damage or repair of damaged hepatocytes are largely limited. Recently, advancement in scientific research has pave the way for the isolation of bioactive phytochemicals with pharmacological effects, which are now used as potential therapeutic agents (Farghali et al. 2015). Extracts from medicinal plants contain different phytochemical compounds including flavonoids as well as other polyphenolic compounds which confer therapeutic effects due to their antioxidative stress properties. Flavonoids are antioxidant phytochemical compounds, consisting of flavones, flavanone, flavanols, flavonols, and flavanonols, which make up a large group of plant secondary metabolites (Chua et al. 2011). They make up an essential part of human diet and are ubiquitous in vegetables, nuts, flowers, seeds, stem, fruits, tea, and wine (Sandhar et al. 2011). Flavonoids in particular are known for their anti-inflammatory and anti-mutagenic properties, as well as their capacity to modulate key cellular enzyme activities (Panche et al. 2016). They also show very good antioxidant (Procházková et al. 2011), anticancer (Souza et al. 2018) and hepatoprotective effects (Zhang et al. 2018), and function as scavengers for free radicals by rapid donation of hydrogen atoms (Kumar and Pandey 2013).
Effects of 27 natural products on drug metabolism genes in channel catfish (Ictalurus punctatus) cell line
Published in Xenobiotica, 2020
Zhenyue Wang, Yongtao Liu, Xiaohui Ai, Liqiao Zhong, Gang Han, Jinlong Song, Qiuhong Yang, Jing Dong
Ability of flavonols to modify CYP450 activity and result in unpredictable health consequences when flavonols are ingested simultaneously with drugs. Duan pointed that quercetin, one of flavonoids, significantly induced CYP3A activity in vivo (Duan et al., 2012). Data also showed in vitro, after exposure with quercetin, the mRNA levels of CYP3A4 and MDR1 were observed significant increase via a vitamin D receptor-dependent pathway (Chae et al., 2015). This result was in agreement with our study which indicated that the expression of CYP3A30 and MDR1 gene was up-regulated by quercetin, but PXR gene had no significant difference in CC-K cells. Given that PXR-CYP3A regulatory pathway is not a closed pathway, but involved with many other transcriptional regulators such as constitutive androstane receptor, vitamin D receptor, aryl hydrocarbon receptor, farnesoid X receptor, and so on (Betts et al., 2015; Chang et al., 2013; Khan et al., 2009), more elaborate researches related to the regulatory pathway are needed.
Polyphenols targeting diabetes via the AMP-activated protein kinase pathway; future approach to drug discovery
Published in Critical Reviews in Clinical Laboratory Sciences, 2019
Saeideh Momtaz, Armin Salek-Maghsoudi, Amir Hossein Abdolghaffari, Eghbal Jasemi, Shamsali Rezazadeh, Shokoufeh Hassani, Mojtaba Ziaee, Mohammad Abdollahi, Sahar Behzad, Seyed Mohammad Nabavi
PPs are a class of natural compounds with a broad diversity of molecular structure. PPs occur in various plant products such as vegetables, fruits, seeds, and legumes, and account for the color, aroma, and taste of plants; they also provide immune protective functions for plant species. To date, more than 8000 structurally different PPs have been identified, and the number is constantly growing [28]. The building blocks of PPs are the polyphenolic skeleton (the aglycone), and the attached sugar moieties and organic acids (the glycone). The glycones attach to other PPs, creating polyphenolic polymers [29]. Based on the phenol rings and the structural details that bind these rings to each other, PPs are divided into five main subclasses; phenolic acids, flavonoids, stilbenes, lignins, and others [30]. Phenolic acids account for a third of the PPs in the diet; caffeic acid, chlorogenic acid, coumaric acid, ferulic acid, and sinapic acid belong to this group; also PPs are found in chicory, kiwi, cherry, berry fruits, apple, coffee, and pear [31]. Flavonoid compounds are the most abundant type of PPs in food sources. To date, more than 4000 flavonoids have been identified. They can be divided into 12 subclasses, of which anthocyanins, flavanones, flavanols, flavones, and isoflavones are the most important types; they are abundantly present in berries, red cabbage, cherries, black grapes, and strawberries [32]. Flavonols include important substances like quercetin, kampferol, and myricetin; they are found mainly in onion, curly kale, leeks, broccoli, and blueberries [33].