Mechanisms of Plant Antioxidants Action

Abstract

The plant kingdom is a rich source of health-promoting compounds and has always played a fundamental role in the isolation, identification, and modification of compounds able to perform several properties on live organisms. Among them, the so-called “antioxidants” have a major potentiality to increase human wellness. Antioxidants are important components in the signaling and defense mechanisms in some plants, where they are precursors of compounds of greater complexity, the modulator of plant growth, and the defensive system against pathogenic organisms and predators. The extraordinary variety of chemical structure and substitution present in the different plant antioxidants make them an inestimable source of interesting compounds, with the ability to counter reactive oxygen/nitrogen species (ROS/RNS) and to stimulate the activation of signal cascade inside the cells. The mechanisms by which antioxidants detoxify these dangerous compounds are complex and involve either direct or indirect interaction with radicals. Antioxidants inhibit or quench free radical reactions mainly based on their reducing capacity or hydrogen atom-donating capacity, their solubility, and chelating properties. Moreover, their ability to modulate key metabolic enzymes and activate/block gene transcription also has remarkable importance.

Evaluation of the Biological Activity of Hydrogel with Cornus mas L. Extract and Its Potential Use in Dermatology and Cosmetology

“…This is largely related to their ability to donate hydrogen atoms, their solubility and chelating properties. In addition to their ability to modulate the activity of the key enzymes mentioned above, phytochemicals contained in plant extracts can also activate or block the transcription of many genes involved in antioxidant defense [29]. The differences in antioxidant activity among the tested samples resulted from different contents of biologically active compounds, which resulted from the use of different extractants during The antioxidant effect of the tested extracts and hydrogels is certainly related to the antioxidant activity of the phytochemicals contained in dogwood fruits.…”

Chemical Composition, Biological Activities and In Silico Analysis of Essential Oils of Three Endemic Prangos Species from Turkey

“…Supplementation of exogenous antioxidants or increasing endogenous antioxidant defenses of the body is a promising way of fighting the undesirable effects of reactive oxygen species (ROS) induced oxidative damage [ 33 ]. The plant kingdom is a rich source of health-promoting compounds especially as natural antioxidants [ 34 ]. Several studies have accentuated on the high antioxidant capacity of plants, their derivatives such as EOs and isolated compounds in the recent years, thus highlighting their usefulness in pharmaceutical, cosmetics, food and beverage industries, especially as some synthetic antioxidants such as BHA and BHT are now suspected to be potentially harmful to human health [ 35 , 36 , 37 , 38 , 39 ].…”

ICP-MS based metallomics and GC-MS based metabolomics reveals the physiological and metabolic responses of Dendrobium huoshanense plants exposed to Fe3O4 nanoparticles

“…The Chlorogenic acid content was significantly reduced in the treatment group; moreover, a number of metabolites with the capacities of ROS scavenging, namely 4-hydroxybenzoate, 3-hydroxybenzoic acid, 3, 4-dihydroxyhydrocinnamic acid, salicylic acid, hydroquinone, noradrenaline, 1, 2, 3-trihydroxybenzene, 1, 2, 4-benzenetriol were decreased by 16–49% in response to the Fe 3 O 4 NPs compared with the control ( Figure 5 ). On the one hand, these substances are consumed as reducing agents, acting as hydrogen donors to inhibit or quench a free radical ( 60 ). Given the large amounts of ferric and ferrous iron available on the surface of Fe 3 O 4 NPs, they exhibit peroxidase-like activity because of their ability to catalyze the oxidation of peroxidase substrates ( 61 ).…”