Influence of Ultra-High-Pressure Pretreatment Method on Chemical Constituents, Antioxidant and Cytoprotective Activities of Free, Esterified, and Bound Phenolics from Anneslea Fragrans Wall. Leaves.

Anneslea fragrans Wall., an edible and medicinal plant, is traditionally used to treat liver and gastrointestinal diseases. This paper aimed to investigate the influence of ultra-high pressure (UHP) pretreatment on the phenolics profiling, antioxidant, and cytoprotective activities of free (FP), esterified (EP), and bound (BP) phenolics from A. fragrans leaves. A total of 32 compounds were characterized and quantified. The davidigenin (44.46 and 113.37 mg/g extract) was the highest in A. fragrans leaves. The vitexin (9), afzelin (10), coreopsin (15), and davidigenin (28) were analyzed with MS2 fragment pathways. Results showed that UHP treated A. fragrans leaves had higher total phenolic (TPC) and total flavonoid (TFC) contents of FP, EP, and BP fractions than those in the raw leaves. Moreover, UHP pretreated A. fragrans leaves had higher scavenging activities on DPPH+• and ABTS+•, and inhibitory effects on the intracellular ROS generation in H2O2-induced HepG2 cells. UFP showed the highest inhibition of ROS production among the samples. Therefore, UHP pretreatment method might be used as an effective strategy for elevating the availabilities of A. fragrans leaves to develop functional foods.

Exploring the Promotive Effects and Mechanisms of Different Polyphenolic Extracts from Prinsepia utilis Royle Seed Shell on Tyrosinase.

Prinsepia utilis Royle (P. utilis) is commonly used as a food ingredient and herbal medicine according to folk records, yet little research has been done on the seed shell, a processing waste. The aim of this study was to investigate the distribution of polyphenolic components and the tyrosinase activation activity of different extracts from the seed shell by UHPLC-ESI-HRMS/MS, in vitro tyrosinase activity assay, molecular docking and molecular dynamics. A total of 16 phytochemicals were identified, of which (+)-catechin and (-)-epicatechin were the major polyphenolic compounds. Both the esterified and insoluble bound polyphenols exhibited tyrosinase activation activity, and the esterified polyphenols showed better tyrosinase activation activity. (+)-Catechin and (-)-epicatechin might be the main activators of tyrosinase, both of which may act as substrate to affect tyrosinase activity. By molecular docking and molecular dynamics simulation studies, (+)-catechin and (-)-epicatechin can be efficiently and stably bound to the tyrosinase active site through hydrogen bonds, van der Waals forces and π-bonds. The results of this study may not only provide a scientific basis for exploring P. utilis seed shell as a potential activator of tyrosinase, but also contribute to the high value utilization of P. utilis processing by-products.

UHPLC-ESI-HRMS/MS analysis on phenolic compositions of different E Se tea extracts and their antioxidant and cytoprotective activities.

E Se tea, prepared from the leaves of Malus toringoides (Rehd.) Hughes, is a traditional beverage, but there is little known about its chemical substances. This paper is aimed to investigate the chemical composition, antioxidant, and cytoprotective activities of the extract and fractions from E Se tea. Sixteen compounds were characterized by UHPLC-ESI-HRMS/MS. Phloridzin was the main compound, especially in ethyl acetate fraction (EAF). Moreover, EAF had the highest total phenolic and flavonoid contents with 197.54 ± 7.52 mg gallic acid equivalents/g extract and 85.94 ± 5.39 mg rutin equivalents/g extract, respectively, and exhibited the strongest antioxidant capacity (DPPH: IC50 = 54.91 ± 3.38 µg/mL; ABTS: IC50 = 98.08 ± 6.92 µg/mL). Different fractions of E Se tea, especially EAF, significantly inhibited intracellular ROS generation, reduced cell apoptosis, and decreased oxidative stress damage in H2O2-induced HepG-2 cells. Therefore, the obtained results highlight that E Se tea is a promising source for functional beverage or nutritional foods.

Phenolic profiles, antioxidant activities and cytoprotective effects of different phenolic fractions from oil palm (Elaeis guineensis Jacq.) fruits treated by ultra-high pressure.

The present work investigated the phenolic profiles, antioxidant activities, and cytoprotective effects of the free, esterified, and insoluble-bound phenolic fractions from oil palm fruits treated under ultra-high pressure (UHP). Results showed that UHP treatment significantly increased the total phenolic and flavonoid contents of all three phenolic fractions (p < 0.05). A total of 11 and 12 phenolic compounds were detected and quantified in non-treated and UHP-treated fruits, with caffeic acid having the highest concentration in insoluble-bound phenolic fractions with 8.68 and 11.27 mg/g of dry extract, respectively. The antioxidant activities, intracellular reactive oxygen species inhibition, and cytoprotective effects of all three phenolic fractions were dramatically enhanced after UHP pretreatment (p < 0.05). Therefore, UHP-treated oil palm fruits with increased bioactivities could be used in functional food or the nutraceutical industry to enhance their applications and economic value.

Phenolic Composition, Antioxidant Properties, and Inhibition toward Digestive Enzymes with Molecular Docking Analysis of Different Fractions from Prinsepia utilis Royle Fruits.

The present study investigated the phenolic profiles and antioxidant properties of different fractions from Prinsepia utilis Royle fruits using molecular docking analysis to delineate their inhibition toward digestive enzymes. A total of 20 phenolics was identified and quantified. Rutin, quercetin-3-O-glucoside, and isorhamnetin-3-O-rutinoside were the major phenolic compounds in the total phenolic fraction and flavonoid-rich fraction. The anthocyanin-rich fraction mainly contained cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. All of the fractions exhibited strong radical scavenging activities and good inhibition on cellular reactive oxygen species (ROS) generation in H2O2-induced HepG2 cells, as evaluated by DPPH and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Moreover, the powerful inhibitory effects of those fractions against pancreatic lipase and α-glucosidase were observed. The major phenolic compounds that were found in the three fractions also showed good digestive enzyme inhibitory activities in a dose-dependent manner. Molecular docking analysis revealed the underlying inhibition mechanisms of those phenolic standards against digestive enzymes, and the theoretical analysis data were consistent with the experimental results.