Interaction Mechanism between OVA and Flavonoids with Different Hydroxyl Groups on B-Ring and Effect on Antioxidant Activity

Assessing the impact of food-derived bioactives on digestive proteases by in vitro and in silico approaches

The interactions between food components and digestive tract enzymes can affect nutrient absorption and impact an individual's health. Certain components, particularly polyphenols, are reported to inhibit digestive enzymes and are commonly referred to as anti-nutritional factors. Reports on this subject often contradict each other, highlighting the need for consistent methodologies to assess the potential impact of bioactive compounds. This study evaluated the "in vitro" activity of pepsin, trypsin, and chymotrypsin using ovalbumin, gluten, and haemoglobin as substrates in the presence or absence of twenty-five bioactive natural compounds belonging to different chemical classes at gastro-intestinal physiological concentrations (0.1 mM). The results indicate that bioactives may have opposite effects on proteolytic activity depending on the substrate/enzyme combination and bioactives structure. With ovalbumin as substrate, piceid and resveratrol were described as strong chymotrypsin activators (+1.46- and 1.17-fold change, respectively), phloridzin dihydrate as a weaker activator (+0.41-fold change), while phloretin was a strong inhibitor (-0.65-fold change). A computational approach based on molecular docking and dynamics simulations was used to investigate the interactions between selected bioactives, chymotrypsin and ovalbumin. The "in silico" study included piceid and phloridzin dihydrate, as well as their respective aglycones (resveratrol and phloretin). The results obtained through computational modelling indicate that all four bioactives can interact with chymotrypsin. However, only those bioactives that enhance in vitro proteolytic activity induce a partial unfolding of ovalbumin's structure. This suggests that the effect of bioactive compounds on protein digestion may be substrate-dependent, and may vary depending on the specific protein being digested.

Probing the Interaction between Isoflucypram Fungicides and Human Serum Albumin: Multiple Spectroscopic and Molecular Modeling Investigations

To better understand the potential toxicity risks of isoflucypram in humans, The interaction between isoflucypram and HSA (human serum albumin) was studied through molecular docking, molecular dynamics simulations, ultraviolet-visible absorption, fluorescence, synchronous fluorescence, three-dimensional fluorescence, Fourier transform infrared spectroscopies, and circular dichroism spectroscopies. The interaction details were studied using the molecular docking method and molecular dynamics simulation method. The results revealed that the effect of isoflucypram on human serum albumin was mixed (static and dynamic) quenching. Additionally, we were able to obtain important information on the number of binding sites, binding constants, and binding distance. The interaction between isoflucypram and human serum albumin occurred mainly through hydrogen bonds and van der Waals forces. Spectroscopic results showed that isoflucypram caused conformational changes in HSA (human serum albumin), in which the α-helix was transformed into a β-turn, β-sheet, and random coil, causing the HSA structure to loosen. By providing new insights into the mechanism of binding between isoflucypram and human serum albumin, our study has important implications for assessing the potential toxicity risks associated with isoflucypram exposure.

Cardioprotective Properties of Kaempferol: A Review

Cardiac diseases, such as myocardial infarction and heart failure, have become a major clinical problem globally. The accumulating data demonstrate that bioactive compounds with antioxidant and anti-inflammatory properties have favorable effects on clinical problems. Kaempferol is a flavonoid found in various plants; it has demonstrated cardioprotective properties in numerous cardiac injury models. This review aims to collate updated information regarding the effects of kaempferol on cardiac injury. Kaempferol improves cardiac function by alleviating myocardial apoptosis, fibrosis, oxidative stress, and inflammation while preserving mitochondrial function and calcium homeostasis. However, the mechanisms of action of its cardioprotective properties remain unclear; therefore, elucidating its action could provide insight into directions for future studies.

Research advance of non-thermal processing technologies on ovalbumin properties: The gelation, foaming, emulsification, allergenicity, immunoregulation and its delivery system application

Ovalbumin (OVA) is the most abundant protein in egg white, with excellent functional properties (e.g., gelling, foaming, emulsifying properties). Nevertheless, OVA has strong allergenicity, which is usually mediated by specific IgE thus results in gut microbiota dysbiosis and causes atopic dermatitis, asthma, and other inflammation actions. Processing technologies and the interactions with other active ingredients can influence the functional properties and allergic epitopes of OVA. This review focuses on the non-thermal processing technologies effects on the functional properties and allergenicity of OVA. Moreover, the research advance about immunomodulatory mechanisms of OVA-mediated food allergy and the role of gut microbiota in OVA allergy was summarized. Finally, the interactions between OVA and active ingredients (such as polyphenols and polysaccharides) and OVA-based delivery systems construction are summarized. Compared with traditional thermal processing technologies, novel non-thermal processing techniques have less damage to OVA nutritional value, which also improve OVA properties. OVA can interact with various active ingredients by covalent and non-covalent interactions during processing, which can alter the structure or allergic epitopes to affect OVA/active components properties. The interactions can promote OVA-based delivery systems construction, such as emulsions, hydrogels, microencapsulation, nanoparticles to encapsulate bioactive components and monitor freshness for improving foods quality and safety.