How to express the antioxidant properties of substances properly?

Abstract

Oxidative stress, associated with an imbalance between the oxidants (reactive oxygen species) and the antioxidants in the body, contributes to the development of many diseases. The body’s fight against reactive oxygen species is supported by antioxidants. Nowadays, there are too many analytical methods, but there is no one universal technique for assessing antioxidant properties. Moreover, the applied different ways of expressing the results lead to their incompatibility and unreasonable interpretation. The paper is a literature review concerning the most frequent ways of antioxidant activities expression and for an easy and universal method of the obtained results discussion. This paper is an attempt to point out their disadvantages and advantages. The manuscript can support the searching interpretation of the obtained results which will be a good tool for the development of a number of fields, especially medicine what can help in the future detection and treatment of many serious diseases. Graphic abstract

New Insight on the Bioactivity of Solanum aethiopicum Linn. Growing in Basilicata Region (Italy): Phytochemical Characterization, Liposomal Incorporation, and Antioxidant Effects

“…In contrast, the reducing power evaluated by Khatoon et al on Indian S. aethiopicum fruits was higher than that obtained from the whole fruit of the Lucanian species (20.03 ± 0.17 mgGAE/g DW vs. 9.80 ± 0.58 mgTE/g DW, respectively) investigated in this study [21]. However, this may be due to the different antioxidant standards used for the quantification, since they used gallic acid, which is more potent than Tolox [25].…”

Brewers' spent grain extract as antioxidants in starch‐based active biopolymers

“…The percentage of inhibition for the ABTS ●+ and DPPH ● scavenger methods was based on the changes in absorbance relative to its initial value, after a specified duration reaction. The percentage of inhibition can vary from 0% to 100%, and the higher the inhibition percentage, the greater the antioxidant activity (Olszowy‐Tomczyk, 2021).…”

Synthesis and antioxidant activities of benzylic bromophenols inclusive of natural products

“…Many compounds are used as standards for this purpose. In addition, the standard selection and criteria are also related to the stability, price, and solubility of the standard antioxidant in the solvent environment [ 47 ]. The increased absorbance shows the complex formation and increased enhanced reducing effect ( Figure 2A ).…”

“…On the other hand, IC 50 is called the effective concentration that causes 50% removal of oxidants such as radicals in antioxidant studies. It is often used to assess the antioxidant activity [ 47 ]. For DPPH radical scavenging were found to be in following order: BHT (IC 50 : 4.12 μg/mL, r 2 : 0.9690) > 25 (IC 50 : 4.27 μg/mL, r 2 : 0.9016) > 1 (IC 50 : 6.41 μg/mL, r 2 : 0.9961) > 27 (IC 50 : 6.86 μg/mL, r 2 : 0.9018) > 28 (IC 50 : 10.66 μg/mL, r 2 : 0.9652) > BHA (IC 50 : 11.17 μg/mL, r 2 : 0.9030) > Trolox (IC 50 : 11.75 μg/mL, r 2 : 0.8513) > α-Tocopherol (IC 50 : 23.89 μg/mL, r 2 : 0.9732) > 2 (IC 50 : 30.13 μg/mL, r 2 : 0.9457) > 26 (IC 50 : 231.00 μg/mL, r 2 : 0.9652).…”