Ellagic acid is a dietary polyphenol found in numerous fruits and vegetables, possessing several health benefits such as antioxidant, anticancer and anti-atherosclerotic biological properties. The purpose of this study was to explore the pharmacokinetics and tissue distribution of ellagic acid in rats. A simple, rapid, sensitive and specific liquid chromatography–tandem mass spectrometry method to determine the ellagic acid in plasma and tissue samples was developed and validated. The separation was achieved using reversed-phase ultra-performance liquid chromatography (UPLC), and the mass spectrometric detection was achieved using heated electrospray ionization (negative mode) and multiple ion monitoring (m/z 301/229). A sample cleanup with a solid phase extraction (SPE) step prior to the UPLC-MS/MS analysis was also developed. The SPE and UPLC-MS/MS method established here was successfully applied to reveal the pharmacokinetic profiles and tissue distribution of ellagic acid. After oral administration dosing at 50 mg/kg, plasma levels of ellagic acid peaked at about 0.5 h, with C_max value of 93.6 ng/mL, and the results showed that the ellagic acid was poorly absorbed after oral administration. The pharmacokinetic profile of ellagic acid fitted to a two-compartment model with t_1/2α 0.25 h and t_1/2β 6.86 h, respectively. Following oral administration, ellagic acid was detected in all examined tissues including kidney, liver, heart, lung and brain et al., and the highest levels were found in kidney and liver.

Polyphenol extracts from the burs of Castanea mollissima Blume (CMPE) exhibited potential antioxidant and hypoglycemic activities. The α-glucosidase inhibitory activities of CMPE were assessed as a means of elucidating the mechanism behind its hypoglycemic activities. In vitro studies showed that CMPE significantly inhibited both yeast α-glucosidase, through a noncompetitive mode with an IC₅₀ of 0.33 μg/mL, and rat intestinal α-glucosidase. In vivo studies revealed that oral administration of CMPE at doses of 600 mg/kg significantly reduced postprandial blood glucose levels by 27.2% in normal rats following sucrose challenges. Gel permeation chromatography revealed that CMPE exhibited typical characteristics of high-molecular-mass polymers with mean (Mn) and weight (Mw) average molecular weights of 35.4 and 50.7 kDa, respectively, and a polydispersity (Mw/Mn) of 1.432. Acid hydrolysis analysis indicated the presence of ellagitannins. These data suggest that CMPE, enriched with ellagitannins, would be an efficacious dietary supplement for diabetes management through the inhibition of alpha-glucosidase.

Urolithin C includes apoptosis in PC12 cells through a mitochondria-mediated pathway.

Bearing in mind the centuries-old traditional use of chamomile, but also the increasing demand for its products in modern industry, oriented toward sustainable development, there are increasing efforts for the efficient extraction of high-value compounds of this plant, as well as obtaining its products with added value. With that goal, conventional and contemporary separation techniques were applied in this work. Both hydrodistillation processes (HD), conducted in a traditional manner and coupled with microwave irradiation (MWHD), were used for essential oil isolation. In parallel with those procedures, chamomile lipophilic extracts were obtained by Soxhlet extraction applying organic solvents and using supercritical fluid extraction as a greener approach. The obtained extracts and essential oils were characterized in terms of chemical composition (GC analysis, contents of total phenolics and flavonoids) and biological potential. GC analysis revealed that oxygenated sesquiterpenes and non-terpene compounds were the dominant compounds. α-Bisabolol oxide A (29.71–34.41%) and α-bisabolol oxide B (21.06–25.83%) were the most abundant individual components in samples obtained by distillation while in supercritical and Soxhlet extracts, major compounds were α-bisabolol oxide A and pentacosane. The biological potential of essential oils and extracts was tested by applying a set of analyzes to estimate the inhibition of biologically important enzymes (amylase, glucosidase, acetylcholinesterase, butyrylcholinesterase, tyrosinase) and antioxidant capacity (DPPH, ABTS, CUPRAC, FRAP, chelating and total antioxidant capacity). The results suggested essential oils as better antioxidants, while the extracts were proven to be better inhibitors of the tested enzymes. Principal Component Analysis was conducted using the experimental results of the composition of extracts and EOs of chamomile obtained by different separation techniques, showing clear discrimination between methods applied in correlation with the chemical profile. Molecular docking was applied for the identification of the main active principles present in the essential oil, among which α-bisabolol-oxide B (cp3) showed a higher affinity for tyrosinase.

Chamomile is one of the most consumed medicinal plants worldwide. Various chamomile preparations are widely used in various branches of both traditional and modern pharmacy. However, in order to obtain an extract with a high content of the desired components, it is necessary to optimize key extraction parameters. In the present study, optimization of process parameters was performed using the artificial neural networks (ANN) model using a solid-to-solvent ratio, microwave power and time as inputs, while the outputs were the yield of the total phenolic compounds (TPC). Optimized extraction conditions were as follows: a solid-to-solvent ratio of 1:80, microwave power of 400 W, extraction time of 30 min. ANN predicted the content of the total phenolic compounds, which was later experimentally confirmed. The extract obtained under optimal conditions was characterized by rich composition and high biological activity. Additionally, chamomile extract showed promising properties as growth media for probiotics. The study could make a valuable scientific contribution to the application of modern statistical designs and modelling to improve extraction techniques.

The aim of this Special Issue, entitled “The Extraction, Characterization and Biological Activity of Natural Products”, is to expand our knowledge and promote a better understanding of the latest scientific advances in the field of the extraction, isolation and characterization of biologically active compounds of natural plants