Design of Scaffolds Based on Zinc-Modified Marine Collagen and Bilberry Leaves Extract-Loaded Silica Nanoparticles as Wound Dressings.

Purpose: In this study, wound dressings were designed using zinc-modified marine collagen porous scaffold as host for wild bilberry (WB) leaves extract immobilized in functionalized mesoporous silica nanoparticles (MSN). These new composites were developed as an alternative to conventional wound dressings. In addition to the antibacterial activity of classic antibiotics, a polyphenolic extract could act as an antioxidant and/or an anti-inflammatory agent as well. Methods: Wild bilberry leaves extract was prepared by ultrasound-assisted extraction in ethanol and its properties were evaluated by UV-Vis spectroscopy (radical scavenging activity, total amount of polyphenols, flavonoids, anthocyanins, and condensed tannins). The extract components were identified by HPLC, and the antidiabetic properties of the extract were evaluated via α-glucosidase inhibitory activity. Spherical MSN were modified with propionic acid or proline moieties by post-synthesis method and used as carriers for the WB leaves extract. The textural and structural features of functionalized MSN were assessed by nitrogen adsorption/desorption isotherms, small-angle XRD, SEM, TEM, and FTIR spectroscopy. The composite porous scaffolds were prepared by freeze drying of the zinc-modified collagen suspension containing WB extract loaded silica nanoparticles. Results: The properties of the new composites demonstrated enhanced properties in terms of thermal stability of the zinc-collagen scaffold, without altering the protein conformation, and stimulation of NCTC fibroblasts mobility. The results of the scratch assay showed contributions of both zinc ions from collagen and the polyphenolic extract incorporated in functionalized silica in the wound healing process. The extract encapsulated in functionalized MSN proved enhanced biological activities compared to the extract alone: better inhibition of P. aeruginosa and S. aureus strains, higher biocompatibility on HaCaT keratinocytes, and anti-inflammatory potential demonstrated by reduced IL-1ß and TNF-α levels. Conclusion: The experimental data shows that the novel composites can be used for the development of effective wound dressings.

Old Plant, New Possibilities: Wild Bilberry (Vaccinium myrtillus L., Ericaceae) in Topical Skin Preparation.

Bilberry represents a valuable source of antioxidant substances responsible for its application for the treatment of different conditions (such as inflammation, cardiovascular disease, cancer, diabetes, and different age-related diseases) associated with increased oxidative stress. As oxidative stress might cause skin impairments, we aim to evaluate a topical preparation containing bilberry leaves extract and bilberry seeds oil, obtained as a byproduct of the food industry. To obtain the extracts, the conventional maceration technique for leaves, and supercritical carbon dioxide extraction for seeds were employed. The chemical profile of both actives was achieved by HPLC and GC methods, revealing the presence of phenolic acids (chlorogenic being the most abundant), flavonoids (isoquercetin in the highest amount), and resveratrol in leaves extract, while in seeds oil the essential ω-3 and ω-6 fatty acids were determined in favorable ratio, almost being 1. Antioxidant potential of the wild bilberry extract and seed oil was evaluated using in vitro DPPH and FRAP assays. Finally, effects of the oil-in-water creams with mentioned wild bilberry isolates on the skin were investigated in an in vivo study conducted on healthy human volunteers, revealing the significant beneficial effects when topically applied.

[The experimental evaluation in vivo of hypoglycemic properties of functional food ingredient - polyphenolic food matrix].

The aim of this study was the evaluation of hypoglycemic action of functional food ingredient (FFI) - a polyphenol food matrix in 3-month in vivo experiment with the use of fat male mice C57BL/6. The food matrix was produced by means of incubation of bilberry leaves extract (2% solution, pH 3.6) with buckwheat flour in ratio 1:50 during 45 min at 25 °C. The polyphenol content in experimental batch of matrix was 26.6±0.5 mg-equivalent of gallic acid per 1 g of flour. The experiment was conducted with the use of 46 male mice C57Bl/6c. Blood glucose level was estimated before starting the feeding experiment. An oral fasting glucose tolerance test (GTT) was also conducted, the area under the curve (AUC) was calculated. The animals were randomly divided into 4 groups (according to the body weight, glucose level and AUC): control group K1, fed with standard semisynthetic diet, control group K2 (n=10) and experimental groups G3 and G4 (n=13). The symptoms of type 2 diabetes in groups K2, G3 and G4 were modeled with the use of high-fat high-carbohydrate diet (HFHC diet, 30% fat, 20% sucrose). FFI was included into the diet of animals of experimental groups G3 and G4 in doses 2.5 and 5 g per 100 g of ration, respectively. The GTT test was repeated on the 40th and 82nd days of experiment. On the 15th, 54th and 91st days the insulin resistance test (IRT) was conducted. The consumption of HFHC diet by K2 group animals resulted in development of obesity in these animals to the week 11, which was characterized by increase in the body weight gain (37.1±4.9%) in comparison with control group K1 animals (23.4±2.2%). The introduction of FFI into animal's diet decreased significantly body weight gain of these animals in comparison with K2 group. On the week 8, the significant increase in blood glucose level of animals fed with HFHC diet was found (K2 - 8.2±0.3, G3 - 8.1±0.3, G4 - 8.5±0.3 mmol/L), in comparison with control group K1 (7.1±0.3 mmol/L). On the 91st day of experiment this difference remained significant only for group K2 (9.3±0.6 against K1 group - 7.7±0.3 mmol/L), what shows the beneficial hypoglycemic action of the FFI in both doses (for G3 group - 8.5±0.2, for G4 - 8.4±0.3 mmol/L). On the week 8 the disorder in glucose tolerance was found in animals of group K2, what is one of type 2 diabetes symptoms. The introduction of FFI in a dose 2.5 g/100 g into group G3 diet inhibited the development of these disease symptoms. The introduction of FFI in a higher dose (5 g/100 g of a diet) to a certain extent inhibited the development of insulin resistance. There was no effect of FFI, introduced into animal's diet, on cognitive functions and short-term and long-term memory.

[The prospective of using plant polyphenols as functional food ingredients].

In this review we briefly discuss the publications dedicated to experimental evaluation of hypoglycemic, hypolipidemic and antioxidant properties of different plant polyphenols. The stages of preclinical studies of their efficacy are presented: in silico studies with molecular docking methods and in vivo studies with the use of genetic and medicamental models of type 2 diabetes. The results of own studies present the substantiation of prospects of using the plant polyphenol extracts as functional food ingredients for diet therapy and treatment of patients with type 2 diabetes. It was shown using genetic fatty Zucker rats model that extract consumption led to lower blood glucose level, had beneficial effect on glucose sensitivity and also improved the reaction of insulin-sensitive tissues on exogenous injection of glucose and insulin. Hypoglycemic and hypolipidemic properties of bilberry leaves extract were characterized on male Wistar rats model of carbohydrate metabolism disorder (streptozotocin injection accompanied with consumption of 10% fructose solution). The results of previous studies showed the beneficial effects of bilberry leaves extract on carbohydrate metabolism and determined the task to enhance the efficacy of developed polyphenol ingredient by the way of sorption on protein food matrix - brown buckwheat flour. Thus, a brief review of presented in this article results of foreign and domestic experimental studies shows the prospect of using the individual plant polyphenols and polyphenol plant extracts as phytonutrients for diet therapy and treatment of diseases associated with disorders of carbohydrate and lipid metabolism.