Slovak University of Agriculture in Nitra

 

This was confirmed by extensive research by experts of the Slovak University of Agriculture in Nitra. The team also developed a formula for a functional food and submitted a utility model application under the title "Biscuits with the addition of selenium-fortified oyster mushroom and active mushroom glucan and their production method".

Researchers from the Institute of Nutrition and Genomics of the Faculty of Agrobiology and Food Resources in cooperation with selected laboratories of the AgroBioTech Research Center and the Institute of Horticulture of the Faculty of Horticulture and Landscape Engineering of SUA were devoted to the effects of oyster mushrooms on type 2 diabetes mellitus. The aim of the four-year project entitled Protective effect of oyster mushroom extract in chronic non-communicable diseases was to contribute to the improvement of the health status of consumers with suitable nutrition, especially in risk groups with increased values of glycemia and cholesterol.

The researchers approached the issue comprehensively and solved it in several stages.

During the first stage, they selected the mushroom that has the highest content of active beta-glucan, as well as other bioactive substances. They tracked 69 strains of oyster mushrooms. They selected the strain with the highest content of β-glucans, minerals and fatty acids and used to produce fruiting bodies for the next stages of the project.

Subsequently, they devoted themselves to verifying the effects of the developed extract from a selected strain of oyster mushroom on the human endothelial cell line. A high or low concentration of glucose causes cell growth disorders, reduces their vitality, and cells are exposed to oxidative stress. The aim was to demonstrate that the addition of oyster mushroom extract will prevent such disorders. "Therefore, we affected the cell line with a high concentration of glucose, thereby inducing a hyperglycemic state, which is an important factor in damage to the vascular endothelium in the pathogenesis of diabetes mellitus. The next step was the selection of a suitable concentration of the extract and the evaluation of cell survival in stimulated hyperglycemic conditions. Through experiments, we confirmed that the extract had a positive effect on cell viability, which was significantly negatively affected by increased glucose concentration," said project leader MUDr. Peter Chebo.

Experts also investigated the molecular changes in oyster mushroom extract at the level of changes in gene expression. They evaluated 6 genes involved in the processes of inflammation, apoptosis (programmed cell death) and genes encoding antioxidant enzymes. "The results pointed to the fact that the addition of the extract itself affects the antioxidant status of the cells. With the help of the extract, we can reduce oxidative stress and thereby have a positive effect in the prevention of chronic metabolic diseases," said P. Chlebo.

The researchers also demonstrated the experiments on another model eukaryotic organism, Schizosaccharomyces pombe - unicellular yeast, which represents a prominent model system for evaluating a wide range of biological processes taking place in mammalian cells as well. "By adding the ethanol extract of the oyster mushroom to the culture medium, the vital functions of

S. pombe cells exposed to hypo- and hyperglycemic stress improved to a great extent," the project leader explained.

The research team also devoted itself to the development of innovative products and the optimization of recipes of bakery products with the addition of oyster mushrooms. Oyster mushroom extract significantly influenced the rheological parameters of bakery flours and affected the sensory and technological properties of the final products. The extract was applied to vegetable chips, syrups, candies and dried fruit. As a result, a functional food formula was developed and a utility model application was filed with the title "Biscuits with the addition of selenium-fortified oyster mushroom and active glucan from the mushroom and the method of their production", registered under the identification number PUV 103-2024.

The last stage of the project was a clinical, double-blind and placebo-controlled study, realized in the years 2023-2024. Probands were selected by random selection of dispensary patients, long-term treated for type 2 diabetes mellitus. All probands used the ingredients in the same dose in the form of gelatin biocapsules from mushrooms. "Analysis of the results obtained during the clinical study shows that there was a significant decrease in fasting glucose, a statistically significant decrease in the levels of insulin and the HOMA IR index, as well as glycated hemoglobin, which can be interpreted as an increase in the sensitivity (reduction of insulin resistance) and the effectiveness of the therapy. At the same time, there was an improvement in the values of the lipid spectrum of aC-peptide, which is a very important prerequisite for reducing cardiovascular risk. A significant benefit of the clinical study was a statistically significant increase in iron levels when consuming dried oyster mushroom extract," informed Dr. Chlebo.