Effects of short- and long-term treatments of sardine (Sardina pilchardus) protein hydrolysates on blood lipid concentrations and antioxidant status, in rats fed cholesterol-enriched diets

Hypercholesterolemia is a major risk factor of cardiovascular diseases (CVD). A limited number of experimental studies have shown that sardine protein hydrolysates (SPH) could be a very useful natural compound to prevent hy-percholesterolemia by both improving the lipoprotein profile and modula-ting oxidative stress. In the present study, the effect of short and long term treatments with SPH were examined on serum lipid contents, lipid peroxida-tion and antioxidant enzymes activities in rats fed cholesterol-enriched diet. At day 0, rats were divided into five groups. The group of day 0 was the stan-dard group, and the four remaining groups were divided into two parts of two groups each consuming for 14 or 28 days an hypercholesterolemic diet, and treated (HC-SPH) or not (HC) by gavage with SPH. Compared with day 0, serum TC contents were increased at day 14 and remained unchanged at day 28 in HC-SPH group. These values were decreased in HC-SPH versus HC. Liver and heart TBARS concentrations were increased at day 14 then diminished at day 28 in HC-SPH group. Liver and heart SOD and CAT activities were decrea-sed at short term then remained unchanged at long term in HC-SPH group. In addition, these activities were enhanced in HC-SPH versus HC. In conclusion, these results indicate the potential effects of short and long term treatments of SPH to improved cholesterolemia and reduced radical attack in rats fed high-cholesterol diets.

Cephalexin Degradation Initiated by OH Radicals: Theoretical Prediction of the Mechanisms and the Toxicity of Byproducts

In this work, density functional theory is used to study the local reactivity of cephalexin (CLX) to radical attack and explain the mechanism of the reaction between CLX and hydroxyl radical attack leading to degradation byproducts. The reaction between •OH and CLX is supposed to lead to either an addition of a hydroxyl radical or an abstraction of a hydrogen. The results showed that the affinity of cephalexin for addition reactions increases as it passes from the gas to the aqueous phase and decreases as it passes from the neutral to the ionized form. Thermodynamic data confirmed that OH addition radicals (Radd) are thermodynamically favored over H abstraction radicals (Rabs). The ecotoxicity assessments of CLX and its byproducts are estimated from the acute toxicities toward green algae, Daphnia and fish. The formation of byproducts is safe for aquatic organisms, and only one byproduct is harmful to Daphnia.

New Application of Natural Language Processing（NLP）for Chemist Predicting Intermediate and Providing an Effective Direction for Mechanism Inference

Predicting and proposing the reaction mechanism, as well as speculating the reaction intermediates are great challenges among the development of modern organic chemistry. Herein, a model from Natural Language Processing (NLP) was firstly employed to learn and perform the task of intermediate prediction, which is served as a language translation task. Radical cascade cyclization is prevalently used in life science and pharmaceutical projects, while the regioselectivity of radical attack is difficult to predict. The model is trained on self-built dataset to tackle the challenge. And transfer learning was used to surmount the restriction of limited amounts of data. The NLP transformer model performs well with remarkable accuracy, providing an efficient instruction for mechanism understanding. Manual encoding of rules is not required, thus, providing a favorable tool towards solving the challenging problem of computational organic chemical mechanism inference.

Free Radical Isomerizations in Acetylene Bromoboration Reaction

The experimentally motivated question of the acetylene bromoboration mechanism was addressed in order to suggest possible radical isomerization pathways for the syn-adduct. Addition–elimination mechanisms starting with a bromine radical attack at the “bromine end” or the “boron end” of the C=C bond were considered. Dispersion-corrected DFT and MP2 methods with the SMD solvation model were employed using three all-electron bases as well as the ECP28MWB ansatz. The rate-determining, elimination step had a higher activation energy (12 kcal mol−1) in case of the “bromine end” attack due to intermediate stabilization at both the MP2 and DFT levels. In case of the “boron end” attack, two modes of C–C bond rotation were followed and striking differences in MP2 vs. DFT potential energy surfaces were observed. Employing MP2, addition was followed by either a 180° rotation through an eclipsed conformation of vicinal bromine atoms or by an opposite rotation avoiding that conformation, with 5 kcal mol−1 of elimination activation energy. Within B3LYP, the addition and rotation proceeded simultaneously, with a 9 (7) kcal mol−1 barrier for rotation involving (avoiding) eclipsed conformation of vicinal bromines. For weakly bound complexes, ZPE corrections with MP2 revealed significant artifacts when diffuse bases were included, which must be considered in the Gibbs free energy profile interpretation.

Zygophyllum album aqueous extract reduces oxidative damage in erythrocytes and attenuates pro-inflammatory markers in hypercholesterolemic-diabetic rats

Introduction. Zygophyllum album (Z. album) is used in traditional medicine for a long time for its anti-diabetic activities. Objective. To investigate Z. album extract supplementation effects on redox and inflammatory status in hypercholesterolemic-diabetic rats. Material and methods. Male Wistar rats (n=36), weighing 200±10g were divided into three groups (n=12). The 1st group was hypercholesterolemic (HC) by consuming cholesterol enriched diet (1%). The 2nd group was diabetic (D) by intraperi-toneal injection of streptozotocin (STZ) (35 mg/kg body weight). The 3rd group was hypercholesterolemic-diabetic (HC-D). Each group was divided into two subgroups (n=6), untreated (HC, D, HC-D) and treated groups with 1% Z. album extract (HC-Za, D-Za and HC-D-Za). Results. At d28, Z. album treatment lead to a decrease in erythrocytes thiobarbituric reactive substances (TBARS) in HC-Za (-44%), D-Za (-66%) and HC-D-Za (-23%) groups. Increased erythrocytes antioxidant enzymes activities (superoxide dismu-tase, glutathione peroxidase, glutathione reductase and catalase) were observed in HC-Za, D-Za and HC-D-Za (p<0.05). In plasma, interleukin (IL-1 β and IL-6) concentrations were reduced by -44, -50 and -33%, and -49, 38 and -41%, respectively in treated groups. In plasma, a decrease of TNF-α (Tumor Necrosis Factor-α), homocysteine and protein-C reactive (CRP) was observed in Z. album treated groups (p<0.05). Conclusion. Z. album reduces radical attack and improves anti-inflammatory proprieties in hypercholesterolemic-diabetic rats.

Immobilisation and Release of Radical Scavengers on Nanoclays for Chemical Reinforcement of Proton Exchange Membranes

Mechanical and chemical stability of proton exchange membranes are crucial requirements for the development of fuel cells for durable energy conversion. To tackle this challenge, bi-functional nanoclays grafted with amino groups and with embedded radical scavengers, that is, CeO2 nanoparticles were incorporated into Aquivion® ionomer. The composite membranes presented high proton conductivity and increased stability to radical attack compared to non-modified Aquivion membranes, demonstrating the effectiveness of the approach based on radical scavenger immobilisation and release from clay nanocontainers.