In vivo antioxidant activity of phenolic compounds: Facts and gaps

Abstract

Background: Numerous diseases have been related with free radicals overproduction and oxidative stress. Botanical preparations possess a multitude of bioactive properties, including antioxidant potential, which has been mainly related with the presence of phenolic compounds. However, the mechanisms of action of these phytochemicals, in vivo effects, bioavailability and bio-efficacy still need research.Scope and Approach: The present report aims to provide a critical review on the aspects related with the in vivo antioxidant activity of phenolic extracts and compounds from plant origin.Key findings: Biological functions beyond the human metabolism were discussed, comparing in vivo vs. in vitro studies, as also focusing the conditioning factors for phenolic compounds bioavailability and bio-efficacy. Furthermore, an upcoming perspective about the use of phytochemicals as life expectancy promoters and anti-aging factors in human individuals was provided.Conclusions: Overall, and despite all of those advances, the study of the biological potential of numerous natural matrices still remains a hot topic among the scientific community. In fact, the available knowledge about the responsible phytochemicals for the biological potential, their mechanisms of action, the establishment of therapeutic and prophylactic doses, and even the occurrence of biochemical inter-relations, is considerable scarce.

Antioxidant Capacity of Anthocyanin Pigments

“…Apart from energetics, oxidation supports immunological integrity. While the bulk of epidemiological evidence supports the nutritional/health value of fruits and vegetables [4,11,12,19,22,33,39,40,50], the doses of individual components they contain, such as specific antioxidants that may contribute to improved health and reduced risk of certain diseases, remain uncertain.…”

“…However, the issue of food antioxidants although important is a controversial topic [11,64,72,[363][364][365]. The plethora of published studies on mechanisms [132] that may mediate therapeutic or chemical chemopreventive effects of dietary constituents contrasts sharply with a scarcity of information on their pharmaceutical and clinical-pharmacological properties.…”

“…Phenolic compounds have attracted the attention of researchers for decades [4][5][6][7]. This was initially due to their physiological importance to plants, mainly relating to pigmentation and flavour [8,9] and, more recently, because of their free radical scavenging capacity, which, among other biological effects, increases antioxidant activity and prevents cellular oxidation [10,11].…”

Flavonoid Derivatives from the Aerial Parts of Trifolium trichocephalum M. Bieb. and Their Antioxidant and Cytotoxic Activity

“…C-7), 161.1 (C-5), 156.6 (C-9), 148.1 (C-4'), 147.2 (C-2), 145.5 (C-3'), 136.1 (C-3), 122.4 (C-1'), 120,5 (C-6'), 116.0 (C-5'), 115.4 (C-2'), 103.4 (C-10), 98.6 (C-6), 93.8 (C-8) 1 H NMR and 13 C NMR data agree with the data given in the literature for quercetin [15] (Figure 1). The correlation between phenolic compounds and strong antioxidant activity has been showed with many studies up to date [17]. Also it has been known that isoflavonoids show antioxidant activity and some of the beneficial effects of them are reported to be connected with this activity [18].…”

Chemical Profiling of Polyfloral Belgian Honey: Ellagic Acid and Pinocembrin as Antioxidants and Chemical Markers

“…The most important feature of these compounds is their antibacterial and antioxidant activity [1][2][3][4][5]. Dietary studies have clearly shown a correlation between the content of phenolic compounds in plant foods and a decrease in the incidence of lifestyle diseases [6,7]. From a wide variety of honeys, consumers frequently choose unifloral honeys because their specific medicinal properties are well defined.…”