Research in phytochemical composition and hypoglycemic activity screening of the dry extracts from bearberry leaves

Abstract

Diabetes mellitus is a global medical and social issue. In the developed countries of the world, from 5 to 12% of the population are diagnosed with diabetes mellitus and, according to WHO prognosis, the level of this disease may increase to 30-35%. Type 2 diabetes is a disease that progresses over time, but the rational and systematic use of hypoglycemic synthetic drugs and phytopreparations can significantly delay the onset of insulin therapy. A promising source of BAS with a hypoglycemic effect is the raw material of plants of the Heather family, namely, bearberry leaves. However, on the Ukrainian market there are no domestic galenic and novo-galenic preparations based on biologically active substances of this raw material, which indicates the prospects for the development of new drugs, including those with hypoglycemic action. The aim. The aim of the study was to study the phytochemical composition and to carry out a screening of the hypoglycemic activity of dry extracts from bearberry leaves modified with various amino acids to identify promising substances with hypoglycemic action. Materials and methods. The objects of the study were 11 dry extracts from bearberry leaves, 10 of which were modified with various amino acids. The study of the phenolic compounds of the extracts was carried out by TLC, HPLC, and spectrophotometry. To assess the hypoglycemic activity of the extracts, two experiments were carried out - primary screening and oral glucose tolerance test. Results. Using TLC and HPLC, in the extracts obtained arbutin, gallic acid, 5 flavonoids were identified, among which hyperoside was dominant, 4 hydroxycinnamic acids, among which chlorogenic and caffeic acids were dominant, and their content was established. In the extracts obtained, main groups of phenolic compounds were quantified using a spectrophotometric method. Dry extracts from bearberry leaves, modified with cysteine, arginine and glutamic acid, showed the strongest hypoglycemic activity. Conclusions. The chemical composition of phenolic compounds and the hypoglycemic activity of dry extracts from bearberry leaves modified with 10 different amino acids were determined. The most promising substances turned out to be extracts modified with cysteine, arginine and glutamic acid; therefore, they are promising agents for the development of new drugs.

American Cranberry (Oxycoccus macrocarpus (Ait.) Pursh) Leaves Extract and Its Amino-Acids Preparation: The Phytochemical and Pharmacological Study

“…Previous studies have shown that plants in the Vaccinium genus are promising sources for the creation of hypoglycemic and hypolipidemic agents because of their significant antioxidant activity, namely extracts from bilberry leaves [ 16 ], blueberry leaves [ 17 ] and bearberry leaves [ 18 , 19 ]. Studies have shown that extracts from the leaves of cranberries are also promising when used to correct insulin-resistant conditions [ 20 , 21 ].…”

“…The modification of a blueberry-leaves extract with arginine led to the creation of a new remedy with pronounced hypolipidemic and hypoglycemic effects [ 16 ]. The combination of phenylalanine with a bearberry-leaves extract allowed the researchers to obtain a product with anti-inflammatory and pronounced diuretic activity [ 18 , 19 ] and with cysteine—a new one for insulin resistance management [ 25 ].…”

Phytochemical and Pharmacological Research of the American Cranberry (Oxycoccus macrocarpus (Ait.) Pursh) Leaves Extract and its Aminoacids Preparation with Hepatoprotective Activity

“…Previous studies have shown that plants of the Vaccinium genus are promising sources for the creation of hypoglycemic and hypolipidemic agents, because of their significant antioxidant activity, namely extracts from bilberry leaves [18,19], blueberry leaves [20] and bearberry leaves [21,22].…”

“…The modification of the blueberry leaves extract with arginine allowed to create a substance with pronounced hypoglycemic and hypolipidemic activities [18]. The modification of the extract of bearberry leaves with phenylalanine allowed to create a substance with a pronounced diuretic and anti-inflammatory effect [21,22] and adding cysteine -a remedy for the management of insulin resistance [28]. All of this indicates the viability of the chosen direction.…”

Chemical Composition and Insulin-Resistance Activity of Arginine-Loaded American Cranberry (Vaccinium macrocarpon Aiton, Ericaceae) Leaf Extracts

“…Previous studies have shown that the extracts obtained from the leaves of Vaccinium genus species are promising for formulating hypoglycemic and hypolipidemic medicines. More specifically, such extracts were obtained, e.g., from bilberry leaves [10,11], highbush blueberry leaves [12], and bearberry leaves [13,14]. Moreover, the extracts of American cranberry leaves were proven to have hepatoprotective effects [8].…”