Influence of different preparation techniques on the composition and antioxidant action of curcumin and curcuminoids

Epidemiological evidence indicates that plant antioxidants activity can treat or help to prevent the development of various diseases. One species with great potential as an antioxidant is Curcuma longa. However, different extraction techniques can influence isolated chemical compounds. This study investigated chemical composition and antioxidant activity of two rhizome extracts of C. longa: hydroethanolic, obtained by exhaustion (HECLex); and dried by a spray dryer (HECLsd). The phytochemical composition was evaluated by GC/MS. Antioxidant activity was evaluated using DPPH and FRAP assays. Total phenolic compounds and soil analyses were performed. The main components of HECLex were ar-turmerone, γ-curcumene, α-turmerone, and β-sesquiphellandrene. The main components of HECLsd were 9,12,15-octadecatrienoic acid, 2,3-bis([trimethylsilyl]oxy)propyl ester, verrucarol, and 1-monolinoleoylglycerol trimethylsilyl ether. HECLsd had significantly higher levels of phenolic compounds and higher antioxidant capacity compared with HECLex. In conclusion, processes of the preparation of C. longa rhizomes alter the chemical components and consequently their biological activity.

Plant Antioxidants for Food Safety and Quality: Exploring New Trends of Research

Antioxidants are an heterogeneous group of compounds able to counteract cell oxidation by acting as reducing agents, as free radical scavengers, and quenchers of radical species and other pro-oxidants, such as metals [...]

PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY GLYCYRRHIZA PALLIDIFLORA HERB (GLYCYRRHIZA PALLIDIFLORA MAXIM.)

Pale-flowered licorice (Glycyrrhiza pallidiflora Maxim.) is the pea family (Fabaceae) perennial herb. It is a Russian Far East endemic. Pale-flowered licorice refers to the false (not sweet) licorice section (Pseudoglycyrrhiza Krug.), which do not accumulate glycyrrhizin derivatives. The G. pallidiflora successful introduction has been carried out over the past 5 years in the “Apothecary garden” territory, FRC UUH SB RAS, Kemerovo. Phytochemical studies screening biologically active compounds main classes of the plant aerial part confirmed the presence of a complex of phenolic compounds. The content of catechin derivatives and condensed-type tannins - proanthocyanidins (PAC) data in G. pallidiflora herb were obtained for the first time. In different years of cultivation, licorice herb accumulates phenolic compounds - up to 2.83 ± 0.22% in terms of gallic acid, flavonoids - up to 2.44 ± 0.03% in terms of rutin and PAC in terms of cyanidine chloride - up to 2.61 ± 0.11%. It was found that the maximum content of the phenolic compounds and PAC sum was observed in the herb for 4 years development. The greatest number of flavonoids accumulates in the herb harvested in the 3rd year of cultivation. A positive significant linear relation was found between antioxidant activity (AOA) and the total phenolic compounds and PAC content (r≥0.98). Considering that BAC with IC values ≤ 50 μg / ml in the DPPH assay refer to active antioxidant’s licorice herb can be classified as a plant with high antioxidant potential. It was found that the iron chelating activity of the G. pallidiflora herb is in direct dependence (r≥0.94) on the content of flavonoids. The obtained results demonstrate the importance of further study of this plant as a source of BAC, including plant antioxidants.

Plant Foods Rich in Antioxidants and Human Cognition: A Systematic Review

Oxidative stress can compromise central nervous system integrity, thereby affecting cognitive ability. Consumption of plant foods rich in antioxidants could thereby protect cognition. We systematically reviewed the literature exploring the effects of antioxidant-rich plant foods on cognition. Thirty-one studies were included: 21 intervention, 4 cross-sectional (one with a cohort in prospective observation as well), and 6 prospective studies. Subjects belonged to various age classes (young, adult, and elderly). Some subjects examined were healthy, some had mild cognitive impairment (MCI), and some others were demented. Despite the different plant foods and the cognitive assessments used, the results can be summarized as follows: 7 studies reported a significant improvement in all cognitive domains examined; 19 found significant improvements only in some cognitive areas, or only for some food subsets; and 5 showed no significant improvement or no effectiveness. The impact of dietary plant antioxidants on cognition appears promising: most of the examined studies showed associations with significant beneficial effects on cognitive functions—in some cases global or only in some specific domains. There was typically an acute, preventive, or therapeutic effect in young, adult, and elderly people, whether they were healthy, demented, or affected by MCI. Their effects, however, are not attributable only to anti-oxidation.