Isolation and identification of polyphenol monomers from celery leaves and their structure-antioxidant activity relationship

In vitro digestibility and hepato-protective potential of Lophatherum gracile Brongn. leave extract

Lophatherum gracile Brongn. (L. gracile) is a traditional herb for both medicine and food use, but its digestibility and hepato-protective activity is unknown. Herein we investigated the digestibility and hepato-protective potential of L. gracile leave extract (LGE) using in vitro digestion and alcohol-induced oxidative damage models. Compared to the undigested group, the content of phenolics/flavonoids and the antioxidant activity in LGE generally decreased by 9.30-19.97% in the oral and small intestine phase after digestion, while that increased by 9.96-10.17% in the gastric phase. The main phenolics/flavonoids showed promising stability during digestion and their bio-accessiblity ranged from 67.64% to 84.47%. By reducing cellular reactive oxidative species and malonaldehyde levels, LGE (0.23-0.45 mg/mL) pretreatment significantly ameliorated alcohol-induced oxidative damage in HepG2 cells (P < 0.05), and their survival rate increased from 59.23% to 67.76%. These findings suggested that L. gracile could be used for the development of hepato-protective foods.

Polyphenols in Plants: Structure, Biosynthesis, Abiotic Stress Regulation, and Practical Applications (Review)

Phenolic compounds or polyphenols are among the most common compounds of secondary metabolism in plants. Their biosynthesis is characteristic of all plant cells and is carried out with the participation of the shikimate and acetate-malonate pathways. In this case, polyphenols of various structures are formed, such as phenylpropanoids, flavonoids, and various oligomeric and polymeric compounds of phenolic nature. Their number already exceeds 10,000. The diversity of phenolics affects their biological activity and functional role. Most of their representatives are characterized by interaction with reactive oxygen species, which manifests itself not only in plants but also in the human body, where they enter through food chains. Having a high biological activity, phenolic compounds are successfully used as medicines and nutritional supplements for the health of the population. The accumulation and biosynthesis of polyphenols in plants depend on many factors, including physiological-biochemical, molecular-genetic, and environmental factors. In the review, we present the latest literature data on the structure of various classes of phenolic compounds, their antioxidant activity, and their biosynthesis, including their molecular genetic aspects (genes and transfactors). Since plants grow with significant environmental changes on the planet, their response to the action of abiotic factors (light, UV radiation, temperature, and heavy metals) at the level of accumulation and composition of these secondary metabolites, as well as their metabolic regulation, is considered. Information is given about plant polyphenols as important and necessary components of functional nutrition and pharmaceutically valuable substances for the health of the population. Proposals on promising areas of research and development in the field of plant polyphenols are presented.

The Influence of the Use of Different Polysaccharide Coatings on the Stability of Phenolic Compounds and Antioxidant Capacity of Chokeberry Hydrogel Microcapsules Obtained by Indirect Extrusion

The aim of the study was to evaluate the effect of the use of different polysaccharides and their mixtures on the structure of chokeberry hydrogel microcapsules and the stability of polyphenolic compounds and antioxidant capacity during one month of refrigerated storage. As a coating material, alginate and its mixtures with pectin, carrageenan, and chitosan were used, while chokeberry juice and preparation of polyphenolic compounds were used as a core. In non-stored capsules, the addition of carrageenan, pectin, and chitosan to alginate increased the content of total polyphenolic compounds and antioxidant capacity. When compared to non-encapsulated juice, the capsules had a greater decrease in antioxidant capacity during storage. The coating variant composed of alginate and carrageenan was found to be the most beneficial for the preservation of the capsules' phenolic compounds. The findings revealed that proper polysaccharide coating selection is critical for the proper course of the microencapsulation process, the polyphenolic content of chokeberry capsules, and their antioxidant properties.

Evaluation of the Antioxidant and Antifungal Actions of the Optimized Crude Extract and Fractions from the Aerial Parts of Acanthospermum hispidum

This study investigated the phytochemical characteristics of the aerial parts of Acanthospermum hispidum, by chromatographic and spectrophotometric methods, and evaluated the antioxidant and antifungal activities of the crude extract and polyphenol-enriched fractions of the species. The phytochemical prospection showed the presence of polyphenols from the groups of hydroxycinnamic derivatives and flavonoids in the crude extract (CE) and fractions of the aerial parts of A. hispidum. In the chromatographic analysis, it was possible to observe that the fractionation process of the CE with hexane and ethyl acetate was efficient in enriching the fractions in phenolic compounds. This enrichment provided an increase in antioxidant activity by the DPPH and ABTS methods, in which it was observed a higher antioxidant activity for EAF in the DPPH test and higher activity against the ABTS radical by the fractions AqF and RAqF. The extract and fractions were effective against Candida non-Candida albicans strains, mainly against C. glabrata, C. parapsilosis and C. krusei, acting predominantly fungicidal. The results indicate that the aerial parts of A. hispidum can serve as a basis for the development of new antioxidant and antifungal products. Moreover, the fractionation process can contribute to increasing the biological potential of the species.

Root Vegetables-Composition, Health Effects, and Contaminants

Root vegetables are known all over the world, but they are being less and less consumed by individuals. The main purpose of this article was to summarize the benefits, health effects, and threats associated with the consumption of carrot, celery, parsley, beetroot, radish, turnip, and horseradish. They are characterized by high nutritional value due to their richness in dietary fiber, vitamins, and minerals. One of their most important features is their high content of bioactive compounds, such as polyphenols, phenols, flavonoids, and vitamin C. These compounds are responsible for antioxidant potential. Comparison of their antioxidant effects is difficult due to the lack of standardization among methods used for their assessment. Therefore, there is a need for a reference method that would allow for correct interpretation. Moreover, root vegetables are characterized by several health-promoting effects, including the regulation of metabolic parameters (glucose level, lipid profile, and blood pressure), antioxidant potential, prebiotic function, and anti-cancer properties. However, due to the type of cultivation, root vegetables are vulnerable to contaminants from the soil, such as toxic metals (lead and cadmium), pesticides, pharmaceutical residues, microplastics, and nitrates. Regardless, the low levels of toxic substances present in root vegetables do not pose health risks to the average consumer.