Effect of In Vitro Digestion on the Total Antioxidant Capacity and Phenolic Content of 3 Species of Oregano (Hedeoma patens, Lippia graveolens, Lippia palmeri)

Abstract

Oregano is a rich source of polyphenols that have shown bioactive properties like anti-inflammatory potential. However, little is known of the gastrointestinal fate of oregano polyphenols which is imperative to fully understand its bioaccessibility. Our results are important to develop new administration strategies which could help protect the antioxidant and anti-inflammatory potential and bioaccessibility of such compounds.

In vitro bioaccessibility and activity of Greek oregano (Origanum vulgare L. ssp. hirtum (link) Ietswaart) compounds as affected by nitrogen fertilization

“…Studies by Gutiérrez‐Grijalva et al . on Hedeoma patens , Lippia graveolens , and Lippia palmeri described digestion having significant positive or negative influences on phenolics and flavonoids contents and antioxidant activities (RP, DPPH, ORAC, ABTS), depending on the stage of digestion and the antioxidant assay; however, the content of individual phenolic compounds for each step was negatively affected …”

“…23,24,27 Although analysis of bioactive compounds in CE is commonly used for predicting the biological significance of plant materials, some previous work indicated that the digestion process leads to changes in phenolic profiles and in their activity. 17,[28][29][30] In this study, therefore, the in vitro digestion model was applied to determine potential bioaccessibility and activity phytochemicals and to gain a better understanding of the pro-health potential of Greek oregano affected by nitrogen fertilization.…”

“…28 Studies by Gutiérrez-Grijalva et al 35 on Hedeoma patens, Lippia graveolens, and Lippia palmeri described digestion having significant positive or negative influences on phenolics and flavonoids contents and antioxidant activities (RP, DPPH, ORAC, ABTS), depending on the stage of digestion and the antioxidant assay; however, the content of individual phenolic compounds for each step was negatively affected. 29 Due to the fact that RA is regarded as one of the most abundant compounds in the Lamiaceae family and it is characterized by promising healthy properties, the potential bioaccessibility of this compound was determined. Our studies show that the potential bioaccessibility of RA was relatively low, especially after intestinal digestion (depending on the nitrogen supply: 34.2%-53.1% after gastric digestion and 2.75%-11.2% after intestinal digestion) ( Table 2).…”

“…Differences in the results of different studies may be an effect of different experimental protocols applied to simulate the digestive process. 28,29,36 In comparison to the previous investigations, we included the influence of the 'whole' plant matrix on the potential bioaccessibility of phenolic compounds, thus the raw plant material, instead of plant extracts, was subjected to digestion. Thus, our results representing both the effects of simulated digestion on the stability of Greek oregano compounds and their extractability from the plant matrix.…”

Effects of thermal processing methods and simulated digestion on the phenolic content and antioxidant activity of lotus leaves

“…Studies on the effects of in vitro simulated digestion on the phenolic compounds and their antioxidant activity have found that the digestion of polyphenols in the gastrointestinal tract is affected by gastrointestinal enzymes, the pH of the internal environment, inorganic salts, and other factors, all of which can alter the antioxidant activity of polyphenols (Gutiérrez‐Grijalva, Angulo‐Escalante, León‐Félix, & Heredia, ; Ozdal, Capanoglu, & Altay, ). Similarly, the sample drying method affects the release of phenolic compounds (Ji et al, ).…”