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Oxidation of β -carotene by a peroxyl radical and relation of oxidation products to carotenoid activity. (I) Heterolytic (antioxidant effect).
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It is well-known, that lipid antioxidants can retard the oxidative rancidity of foods caused by atmospheric oxidation, and thus protect oils, fats, and fat-soluble components from their quality degradation. In the last few years, much emphasis has been put on the promotion and use of natural antioxidants, commonly occurring in many fruits and veget...
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... understand the mechanism of antioxidant activity of carotenoids it is also important to analyze the oxidation products that are formed during their action as antioxidants. A relationship between product-forming oxidation reactions and carotenoid antioxidant effects has been proposed by Palozza et al. (1995). In more details, it has been reported that the epoxide forming reaction (homolytic cleavage) releases an alkoxyl radical and would not be expected to produce an antioxidant effect (Liebler, 1993). However, heterolytic cleavage would lead to carbonyl fragments, a dialkyl peroxide and other non-radical products, so that β -carotene oxidation by this pathway results in the con- sumption of two peroxyl radicals and thereby to an antioxidant effect (Fig. 2). The activity of carotenoids is also strongly influenced by the oxygen pressure (pO 2 ) of the experimental conditions. Kiokias and Oreopoulou (2006) have observed that certain natural carotenoid mixtures inhibited the azo-inititated oxidation of sunflower oil-in-water emulsions (operated rapidly under low pO 2 ) in terms of both primary and secondary oxidation products. However, other studies (Heinonen et al., 1997; Henry et ...
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... Since synthetic vitamin E and vitamin C have shown inconclusive results regarding their role in cardiovascular health and diseases, various investigators are presently searching for alternate sources of vitamins and other bioactive components such as flavonoids from natural sources like SBT by-products. The effect of the major components of SBT on the cardiovascular system is well documented in scientific research [82][83][84]. Most prospective cohort studies have indicated some degree of inverse association between flavonoid intake and coronary heart disease. ...
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Practical Application
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... One potential explanation for this inhibition could be attributed to the presences of phenolic acids donating hydrogen atoms to lipid radicals, resulting in the formation of more stable lipid derivatives and radicals. These new radicals are less prone to promoting auto-oxidation, contributing to the protective effects against lipid peroxidation [25]. ...
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... 84 86 The ability of phenolic acids to scavenge free radicals, donate H atoms or electrons, or bind metal ions makes them more stable and less easily accessible to promote autoxidation. 87 The antioxidant free radical may also disrupt the chain-propagation processes. However, the influence of antioxidant concentration on autoxidation rates is determined by a variety of parameters, including the structure of the antioxidant, oxidation circumstances, and the type of the sample being oxidized. ...
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... Carotenoids [93][94][95][96][97][98][99][100][101][102][103] Tetraterpenoids called carotenoids absorb light with wavelengths of 400-500 nm. Carotenoids, which give fruits and flowers their colors, are therefore found in plants as red, orange, and yellow pigments. ...
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Osteoarthritis (OA), characterized by degeneration of the joints, is forecast to be the major cause of disability for older people by 2030. The primary pathology of osteoarthritis are cartilage and bone rebuilding. Osteoarthritis management consists of pharmacotherapy, physiotherapy, and surgery. OA should traditionally be treated using herbal medications in various medical systems around the world in addition to steroid use. These provide symptomatic relief from pain and inflammation, but minimally reduce joint destruction. Structural damage needs to be
effectively prevented and should be the main goal of new therapeutic regimens. Phytoconstituents especially belonging to phenolics, flavonoids, steroids, terpenoids, sterols, sesquiterpenes, triterpenes, and phytoalexins class exhibit antioxidant, anti-inflammatory, anti-arthritic effects and prove beneficial in OA. These phytochemicals modulate different targets like cyclooxygenases, lipoxygenases, and other signaling pathways involved in the pathophysiology of OA, thereby
providing immense benefits. These also serve as potential leads for the development of new chemical entities as potential anti-inflammatory molecules of diverse utility. A number of clinical trials have found that herbal remedies and their components are essential to mitigate osteoarthritis. Reflex plus™ is a patented
combination of collagen hydrolysate and rosehip extract. Ingredients in the blend have been thoroughly researched for their efficacy in arthritis. Collagen hydrolysate tends to accumulate within cartilage and assists in repairing the damage
caused by osteoarthritis and other cartilage alterations. The rose hip works on the anti-inflammatory pathway to reduce joint discomfort and inflammation. The most important pro-inflammatory cytokines implicated in the pathogenesis of
osteoarthritis are TNF-α and IL-1β, which act on synoviocytes and chondrocytes by specific interactions with cytokine receptors at the cell surface, assisting in the construction of cartilage for the effective functioning of the joints and the relief of pain associated with osteoarthritis and also help in the protection of cartilage. The
purpose of this chapter is to incorporate the impact of phytochemicals on various molecular targets of inflammation into the overall management of osteoarthritis.
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... In addition, various degradation mechanisms of bioactive molecules, like oxidation, hydrolysis, condensation, enzymatic deterioration, polymerization, and others, can occur due to the heterogeneous composition of the extract (111,113). Incorporating plant extracts as a food ingredient could negatively impact the product's quality due to their distinctive aroma and color (114). Because plant extracts are usually potent antioxidants, rich in phenolic compounds, they are likely to contribute to the bitter taste, astringency, and darkening of manufactured food and beverages (23,104,115,116). ...
Plants are recognized as natural sources of antioxidants (e.g., polyphenols, flavonoids, vitamins, and other active compounds) that can be extracted by green solvents like water, ethanol, or their binary mixtures. Plant extracts are becoming more used as food additives in various food systems due to their antioxidant abilities. Their application in food increases the shelf life of products by preventing undesirable changes in nutritional and sensory properties, such as the formation off-flavors in lipid-rich food. This review summarizes the most recent literature about water or ethanol-water plant extracts used as flavors, colorings, and preservatives to fortify food and beverages. This study is performed with particular attention to describing the benefits of plant extract-fortified products such as meat, vegetable oils, biscuits, pastries, some beverages, yogurt, cheese, and other dairy products. Antioxidant-rich plant extracts can positively affect food safety by partially or fully replacing synthetic antioxidants, which have lately been linked to safety and health issues such as toxicological and carcinogenic consequences. On the other hand, the limitations and challenges of using the extract in food should be considered, like stability, level of purity, compatibility with matrix, price, sensory aspects like distinct taste, and others. In the future, continuous development and a tendency to use these natural extracts as food ingredients are expected, as indicated by the number of published works in this area, particularly in the past decade.
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Despite advances in modern human and veterinary medicine, gastrointestinal (GI) parasitic infections remain a significant health issue worldwide, mainly in developing countries. Increasing evidence of the multi-drug resistance of these parasites and the side effects of currently available synthetic drugs have led to increased research on alternative medicines to treat parasitic infections. The exploration of potential botanical antiparasitics, which are inexpensive and abundant, may be a promising alternative in this context. This study summarizes the in vitro/in vivo antiparasitic efficacy of different medicinal plants and their components against GI parasites. Published literature from 1990–2020 was retrieved from Google Scholar, Web of Science, PubMed and Scopus. A total of 68 plant species belonging to 32 families have been evaluated as antiparasitic agents against GI parasites worldwide. The majority of studies (70%) were conducted in vitro. Most plants were from the Fabaceae family (53%, n = 18). Methanol (37%, n = 35) was the most used solvent. Leaf (22%, n = 16) was the most used plant part, followed by seed and rhizome (each 12%, n = 9). These studies suggest that herbal medicines hold a great scope for new drug discoveries against parasitic diseases and that the derivatives of these plants are useful structures for drug synthesis and bioactivity optimization.
... Phenols, the most common natural antioxidants, are com attached to aromatic hydrocarbon rings. The aromatic natu radical or ion formed on the hydroxyl group to be resonance known to be much more readily oxidized than monophenol phenols occurs by the HAT and SET mechanisms [85]. The an by the number and the arrangement of the hydroxyls on the typical phenol-based antioxidants are shown in Figure 3. ...
... Polyphenols are known to be much more readily oxidized than monophenols. The antioxidant action of phenols occurs by the HAT and SET mechanisms [85]. The antioxidant activity is affected by the number and the arrangement of the hydroxyls on the aromatic ring [86]. ...
This review surveys the major structural features in various groups of small molecules that are considered to be antioxidants, including natural and synthetic compounds alike. Recent advances in the strategic modification of known small molecule antioxidants are also described. The highlight is placed on changing major physicochemical parameters, including log p, bond dissociation energy, ionization potential, and others which result in improved antioxidant activity.
