Catechin and other catechol-containing secondary metabolites: Bacterial biotransformation and regulation of carbohydrate metabolism

Pomegranate peels ethanolic extract in free and nanoemulsified forms around mating and early pregnancy differently affect heat tolerance capacity and reproductive performance of ewes under heat stress

Global warming is seriously threatening sheep farmings by increasing health problems and decreasing reproductive efficiency. In this study, pomegranate peels ethanolic extract (Ppee), rich in phenolic acids, was prepared in free (Fppee) and nanoemulsified (Nppee, with 18.49 nm-21.8 nm particles size) forms. The protective role of the extracts against heat stress impacts on homeothermy, metabolism and redox status, and reproductive performance of ewes was studied. A total of 36 Barki ewes were synchronized to estrus using two intramuscular injections PGF2α. On the day of the first PGF2α, ewes were allocated into three homogeneous experimental groups and received 300 mg/ewe/day Fppee, 300 mg/ewe/day Nppee, or not (control) until day 35 post-mating. The Fppee ewes showed the highest homeothermy in the morning, whereas the Nppee ewes showed the lowest homeothermy in the afternoon (P < 0.001). Both extracts increased plasma total protein, glucose, total antioxidant capacity, and glutathione concentrations (P < 0.001), whereas they decreased plasma urea, cholesterol, and malondialdehyde concentrations compared to control (P < 0.001). The highest and lowest values of these variables were for the Nppee ewes. The Nppee ewes had the significant lowest plasma progesterone concentrations. There were no differences in corpora lutea numbers and diameters. Lambs born to Fppee ewes had the highest birth weights and survivability. In conclusion, supplementing heat-stressed ewes with Fppee improved homeothermy, metabolism, redox status, and lamb weight and survivability without hampering reproductive performance, mainly by decreasing progesterone concentrations as observed in Nppee ewes.

Inhibition mechanisms of α-glucosidase by eight catechins: Kinetic, molecular docking, and surface plasmon resonance analysis

α-Glucosidase is considered to be one of the effective targets for the treatment of type 2 diabetes. This study examined the inhibitory mechanisms of eight catechins on α-glucosidase, including both the free forms (C, EC, GC, EGC) and esterified forms (CG, ECG, GCG, EGCG). Enzyme kinetics and molecular docking studies demonstrated that catechins primarily inhibit α-glucosidase by binding through hydrogen bonds and hydrophobic interactions, with esterified catechins exhibiting stronger inhibitory effects. The structural changes of the proteins following binding were further explored using fluorescence spectroscopy and atomic force microscopy (AFM). Fluorescence spectroscopy revealed that catechins altered the microenvironment around the fluorescent amino acids within the enzyme (such as tyrosine and tryptophan), resulting in slight unfolding of the protein structure. AFM further confirmed that catechin binding to α-glucosidase induced protein aggregation, with esterified catechins exhibiting a more pronounced effect. All of the above findings were based on static model studies. Moreover, the binding kinetics of catechins with α-glucosidase were innovatively investigated using surface plasmon resonance (SPR), revealing that esterified catechins bound more rapidly and displayed higher affinity. The presence of the gallate group in esterified catechins was identified as crucial for their binding to α-glucosidase, resulting in a more significant inhibitory effect. These findings suggested that dietary intake of catechins, especially esterified form, may more effectively inhibit the activity of α-glucosidase.

Recent Advances in the Health Benefits of Phenolic Acids in Whole Grains and the Impact of Processing Techniques on Phenolic Acids: A Comprehensive Review

Phenolic acids, essential compounds in whole grains, are renowned for their health-enhancing antioxidant and anti-inflammatory properties. Variations in concentration, particularly of hydroxybenzoic and hydroxycinnamic acids, are observed among grain types. Their antiobesity and antidiabetes effects are linked to their modulation of key signaling pathways like AMPK and PI3K, crucial for metabolic regulation and the body's response to inflammation and oxidative stress. Processing methods significantly influence phenolic acid content and bioavailability in whole grains. Thermal techniques like boiling, baking, or roasting can degrade these compounds, with loss influenced by processing conditions. Nonthermal methods such as germination, fermentation, or their combination, can protect or enhance phenolic acid content under ideal conditions. Novel nonthermal approaches like ultrahigh pressure (UHP), irradiation, and pulsed electric fields (PEF) show promise in preserving these compounds. Further research is needed to fully comprehend the impact mechanisms of these innovative methods on the nutritional and sensory attributes of cereals.

M2 macrophage-polarized anti-inflammatory microneedle patch for accelerating biofilm-infected diabetic wound healing via modulating the insulin pathway

Macrophages play a pivotal role in the healing of diabetic ulcers. The sustained elevation of glucose levels damages the insulin signaling pathway in macrophages, leading to dysfunctional macrophages that struggle to transition from pro-inflammatory (M1) to reparative (M2) states. Therefore, modulating macrophage inflammatory responses via the insulin pathway holds promise for diabetic ulcer treatment. Additionally, the presence of biofilm impedes drug penetration, and the resulting immunosuppressive microenvironment exacerbates the persistent infiltration of pro-inflammatory M1 macrophages. Therefore, we designed an array of dissolvable microneedle (denoted as NPF@MN) loaded with self-assembled nanoparticles that could deliver NPF nanoparticles, acid-sensitive NPF-releasing Protocatechualdehyde (PA) with hypoglycemic and insulin-like effects, regulating macrophage polarization to an anti-inflammatory M2 phenotype. Additionally, this study extensively examined the mechanism by which NPF@MN accelerates the healing of diabetic ulcers through the activation of the insulin signaling pathway. Through RNA-seq and GSEA analysis, we identified a reduction in the expression of pathway-related factors such as IR, IRS-1, IRS-2, and SHC. Our work presents an innovative therapeutic approach targeting the insulin pathway in diabetic ulcers and underscores its translational potential for clinical management.

Perturbations in Osteogenic Cell Fate Following Exposure to Constituents Present in Tobacco: A Combinatorial Study

Tobacco smoke contains between 7000 and 10,000 constituents, and only an evanescently low number of which have been identified, let alone been evaluated for their toxicity. Recently, the Food and Drug Administration has published a list of 93 chemical tobacco constituents that are harmful or potentially harmful to a number of cellular processes. However, their effect on developing skeletal cells is unknown. In this study, we used ToxPI, a computational tool, to prioritize constituents on this list for screening in osteogenically differentiating human embryonic stem cells and fibroblasts. In selected endpoint assays, we evaluated the potential of these chemicals to inhibit osteogenic differentiation success as well as their cytotoxicity. Six of these chemicals, which were ascribed an embryotoxic potential in our screen, as well as nicotine, which was not found to be osteotoxic in vitro, were then evaluated in combinatorial exposures, either in pairs of two or three. No one single chemical could be pinpointed as the culprit of reduced calcification in response to tobacco exposure. Combining chemicals at their half-maximal inhibitory concentration of differentiation often elicited expected decreases in calcification over the individual exposures; however, cytotoxicity was improved in many of the dual combinations. A reverse response was also noted, in which calcification output improved in combinatorial exposures. Results from ternary combinations reflected those from double combinations. Thus, the results from this study suggest that it may be difficult to isolate single chemicals as the primary drivers of skeletal embryotoxicity and that the full combination of chemicals in tobacco smoke may produce the hypomineralization phenotype that we have so far observed in vitro in human embryonic stem cells as well as in vivo in zebrafish.