Natural Antioxidant Evaluation: A Review of Detection Methods

Abstract

Antioxidants have drawn the attention of the scientific community due to being related to the prevention of various degenerative diseases. The antioxidant capacity has been extensively studied in vitro, and different methods have been used to assess its activity. However, the main issues related to studying natural antioxidants are evaluating whether these antioxidants demonstrate a key role in the biological system and assessing their bioavailability in the organism. The majority of outcomes in the literature are controversial due to a lack of method standardization and their proper application. Therefore, this study aims to compile the main issues concerning the natural antioxidant field of study, comparing the most common in vitro methods to evaluate the antioxidant activity of natural compounds, demonstrating the antioxidant activity in biological systems and the role of the main antioxidant enzymes of redox cellular signaling and explaining how the bioavailability of bioactive compounds is evaluated in animal models and human clinical trials.

Lipidomic Characterization and Antioxidant Activity of Macro- and Microalgae Blend

“…Natural compounds with antioxidant activity are currently of interest mainly in the food and pharmaceutical industries [ 22 ]. Algae total lipid extracts contain lipids that have already been described as powerful antioxidants, such as GL, PL, pigments, and PUFA [ 15 , 57 , 58 ].…”

“…Algae have also drawn attention as a reservoir of antioxidant phytochemicals, in line with the demand for novel antioxidants that is driving the exploration and bioprospection of marine resources [ 18 ]. Antioxidants play a critical role in slowing or preventing oxidative stress events that underlie numerous pathological conditions, principally chronic and degenerative diseases [ 22 ]. Furthermore, they can expand the shelf life of products susceptible to oxidation, such as food and cosmetics, preserving their quality for a longer time period [ 22 ].…”

“…Antioxidants play a critical role in slowing or preventing oxidative stress events that underlie numerous pathological conditions, principally chronic and degenerative diseases [ 22 ]. Furthermore, they can expand the shelf life of products susceptible to oxidation, such as food and cosmetics, preserving their quality for a longer time period [ 22 ]. Algae lipids are a promising eco-friendly alternative to synthetic antioxidants, such as butylated hydroxyanisole (BHA; E-320) or butylated hydroxytoluene (BHT; E-321) [ 17 , 23 ], in conformity with the request of the food and healthcare industries for natural ingredients, encouraged by consumer demand [ 24 ].…”

Synergistic effect of Trikatuk, a traditional Thai formulation, on antioxidant and alpha-glucosidase inhibitory activities

“…The term antioxidant is applied to substances or molecules that can delay or prevent the irreversible damage to other substances or macromolecules and promote health benefits, because oxidative stress causes several pathophysiological processes [ 21 ]. Phenolic compounds, particularly flavonoids, are known as antioxidants because of their ability to scavenge free radicals and chelate metal ions [ 22 ].…”

“…The antioxidant capacity was evaluated by the ABTS and DPPH assays which are simple, rapid, inexpensive, acceptable, and widely used [ 21 , 26 ]. DPPH is the free radical most commonly used in antioxidant screening assays where the capacity of each extract could be classified as very strong (IC 50 < 50 μg/mL), strong (IC 50 50–100 μg/mL), moderate (IC 50 101–150 μg/mL), and weak (IC 50 > 150 μg/mL) [ 27 ].…”