Yu. V. Shatalin

Effects of a Nanocomplex Containing Antioxidant, Lipid, and Amino Acid on Thermal Burn Wound Surface

Dihydroquercetin (flavonoid of plant origin) immobilized with an amino acid in lecithin nanoparticles promotes reduction of inflammatory reactions in the wound after thermal burn. The use of a liposomal complex in burn injury stabilizes endogenous antioxidant system and limits the secondary necrotic zone in the wounds. The treatment was associated with intensification of skin regeneration processes and reparation of hairy follicles and sebaceous glands.

Interaction of C 60 Fullerene-Polyvinylpyrrolidone Complex and Brain Aβ(1-42)Peptide in vitro

Using a spectrophotometric method, changes occurring in solution containing brain Aβ(1–42)-peptide, fullerene C60, and polyvinylpyrrolidone were analyzed. Using the Bent-French method, relative binding constants of fullerene C60 with Aβ(1–42)-peptide and polyvinylpyrrolidone with Aβ(1–42)-peptide were determined. These data suggest that Aβ(1–42)-peptide interacting with the C60 fullerene-polyvinylpyrrolidone complex partially displaces polyvinylpyrrolidone and generates a new three molecular compound.

Partitioning of taxifolin-iron ions complexes in octanol-water system

The composition of taxifolin-iron ions complexes in an octanol-water biphasic system was studied using the method of absorption spectrophotometry. It was found that at pH 5.0 in an aqueous biphasic system the complex of [Tf · Fe2(OH)k(H2O)8 − k] is present, but at pH 7.0 and 9.0 the complexes of [Tf2 · Fe(OH)k(H2O)2 − k] and [Tf · Fe(OH)k(H2O)4 − k] are predominantly observed. The formation of a stable [Tf3 · Fe] complex occurred in octanol phase. The charged iron ion of this complex is surrounded by taxifolin molecules, which shield the iron ion from lipophilic solvent. During transition from water to octanol phase the changes of the composition of complexes are accompanied by reciprocal changes in portion of taxifolin and iron ions in these phases. It was shown that the portion of taxifolin in aqueous solution in the presence of iron ions is increased at high pH values, and the portion of iron ions is minimal at pH 7.0. In addition, the parameters of solubility limits of taxifoliniron ions complexes in an aqueous solution were determined. The data obtained gain a better understanding of the role of complexation of polyphenol with metal of variable valency in passive transport of flavonoids and metal ions across lipid membranes.

The effect of the liposomal form of flavonoid-metal complexes on skin regeneration after chemical burn

The effect of the liposomal form formed by taxifolin and metals of variable valency was investigated. It was shown that application of preparations based on the free flavonoid and its complexes with Fe(II/III) and Cu(II) ions after chemical burns results in more effective skin regeneration and repair of hair follicles and sebaceous glands. A tendency toward more effective wound healing after the application of taxifolin-Cu(II) and taxifolin-Fe(III) liposomal complexes versus control was observed. It was assumed that the mechanism of action of these preparations is based on oxidative polymerization and conjugation of the flavonoid, which results in utilization of toxic metabolites and lipid peroxidation products.

Skin Regeneration after Chemical Burn under the Effect of Taxifolin-Based Preparations

We studied the effect of liposome preparation containing taxifolin oligomers and taxifolin conjugates with carbonyl compounds on skin regeneration after chemical burn. The preparations containing fl avonoid conjugates intensifi ed regeneration processes and reparation of hair follicles and sebaceous glands after chemical burn. The preparation based on taxifolin conjugate with acetaldehyde was most effective; its activity was comparable with that of the wound-healing preparation Olasol. Taxifolin conjugates with carbonyl compounds can be used for the creation of combined wound- and burn-healing preparations.

Oxidation of lecithin in the presence of dihydroquercetin and its complex with divalent iron ions

The ability of the flavonoid dihydroquercetin to prevent or accelerate the accumulation of reactive oxygen species and the metabolites of oxidative stress, carbonyl compounds has been studied. It has been shown on a model of oxidation of lecithin that dihydroquercetin exhibits a prooxidant effect in the alkaline region of pH, whereas at neutral and acidic pH values dihydroquercetin is an effective antioxidant. In the presence of ferrous iron ions, which catalyze the Fenton reaction, dihydroquercetin forms a complex with metal that shows the antioxidant activity in the region of high pH values. It has been found that the oxidation of lecithin in the presence of 20–200 μM ferrous iron is inhibited by dihydroquercetin to a concentration of 3.2 mM. At higher concentration of dihydroquercetin in the presence of ferrous iron, accumulation of malonic dialdehyde occurs, indicating the presence of the prooxidant activity of dihydroquercetin.

Effect of Liposomes Containing Antioxidant, Phospholipid, and Amino Acid on Skin Regeneration after Chemical Burn

Liposomes containing natural flavonoid dihydroquercetin, phospholipid lecithin, and zwitterionic amino acid glycine were used for the therapy of glacial acetic acid-induced chemical burn. No inflammatory reaction was observed in the region of wound. The area of postburn injury did not increase in time. Planimetry and histological studies showed that improved skin regeneration was accompanied by repair of hair follicles and sebaceous glands.

A new material based on collagen and taxifolin: Preparation and properties

The possibility of producing a material based on collagen and a biologically active polyphenol, viz., taxifolin, was investigated, and the properties of the material were studied. The data on the release dynamics and metal-reducing activity of polyphenol that is chemically linked to collagen are represented. The effects of taxifolin, taxifolin glutarate, and a polyphenol-containing gel on the production of reactive oxygen species by neutrophils that are stimulated with phorbol myristate acetate were examined. Polyphenol that was released from the gel was shown to have antioxidant and metal-reducing properties. This suggests that unoxidized polyphenol is effectively included in the collagen gel.

Changes in the ultrastructure and function of goldfish Mauthner neurons in the presence of 3,4-dihydro-2(1H)-pyrimidinethione.

The behavioral effects of 3,4-dihydro-2(1H)-pyrimidinethione (DPT, a pyrimidine derivative), which is used as a test system for detecting tumor growth, on the ultrastructure and function of Mauthner neurons (MN), were studied in goldfish. Application of DPT to MN was found to lead to increased resistance of neurons to exhaustive stimulation, which was accompanied by increases in the sizes of actin-containing membrane desmosome-like contacts, along with the formation of bundles of actin stress fibers; these effects are similar to those previously reported with dopamine. The similarity of the morphofunctional changes in MN on exposure to an artificial chemical substance for which there are no membrane receptors and dopamine itself suggests that they have trophic effects on the stabilization and polymerization of cytoskeletal actin due to direct penetration into postsynaptic neurons.

Study of the cytotoxicity of protein X amyloid fibrils

Amyloid oligomers, protofibrils, and fibrils of various amyloidogenic proteins are known to induce cell death. Tetracycline prevents the formation of fibrils of Aβ peptide and other amyloidogenic proteins and decomposes mature fibrils. It was previously shown that sarcomeric cytoskeletal proteins of the titin family (protein X, protein C, and protein H) in vitro form amyloid fibrils and tetracycline decomposes them. In this work, the concentration and time dependence of the survival of polymorphonuclear leukocytes in the presence of protein X amyloid fibrils is demonstrated. It is also shown that the survival rate increases as fibrils are decomposed by tetracycline. The antibiotic itself is found to be nontoxic. The results obtained show that this approach can be used to evaluate the efficiency of drugs that prevent or rectify amyloidoses.