In Vitro Evaluation of Antidiabetic, Antioxidant, and Anticholinergic Properties of Different Parts of Bilberry (Vaccinium myrtillus L.) From the Eastern Black Sea Region, With LC/MS-MS Analysis of Their Chemical Composition in Food Applications

Abstract

Diabetes, the most prevalent metabolic disorder, is closely linked to Alzheimer's disease, with DM patients showing a two-fold increased risk of developing AD. Bilberry (Vaccinium myrtillus L.) is a prominent wild berry, widely used in juice and food production. This study aimed to evaluate and compare the phytochemical composition and biological activities of different parts of wild V. myrtillus plants, including branches, leaves, and fruits. Using LC-MS/MS, the study quantifies total phenolics, flavonoids, and tannins in each part. Biological activities are assessed through antioxidant activity (ABTS and DPPH assays), anticholinesterase (neuroprotective potential), and antidiabetic effects. The experiments revealed that the Leaf of Yer Ligarba (YLL) extract had the highest values in terms of total phenolic content, total flavonoid content, and total tannin content. Among the extracts, the highest radical scavenging effect was observed with YLL at 86.67% against DPPH. The leaf extracts, Leaf of Dal Ligarba (DLL) and YLL, demonstrated the highest scavenging effects, with inhibition rates of 99.37% and 99.37%, respectively. At one of the common concentrations, 100 μg/mL, acarbose showed 13.12% inhibition, while the Branch of Dal Ligarba (DLB) extract exhibited 98.67% α-glucosidase enzyme inhibition. The highest acetylcholinesterase and butyrylcholinesterase enzyme inhibition activities were observed in the Branch of Yer Ligarba (YLB; 27.08%) and the Fruit of Dal Ligarba (DLF; 16%), respectively. Chlorogenic acid was the most abundant phenolic compound, particularly in the DLL 58,569.80 ng/mL. This study highlighted the significant phytochemical content and biological activities of wild bilberry extracts, demonstrating their potential for managing diabetes and neurodegenerative diseases, particularly Alzheimer's.

Keywords: Alzheimer's disease; Vaccinium myrtillus; antioxidant; bilberry; chlorogenic acid; diabetes.

FIGURE 1

Branches, leaves, and fruits of the V. myrtillus (by Beyzanur Ayar).

FIGURE 2

Chromatogram of phenolic compounds in the branch extract of Dal Ligarba (DLB).

FIGURE 3

Chromatogram of phenolic compounds in the fruit extract of Dal Ligarba (DLF).

FIGURE 4

Chromatogram of phenolic compounds in the leaf extract of Dal Ligarba (DLL).

FIGURE 5

Chromatogram of phenolic compounds in the branch extract of Yer Ligarba (YLB).

FIGURE 6

Chromatogram of phenolic compounds in the fruit extract of Yer Ligarba (YLF).

FIGURE 7

Chromatogram of phenolic compounds in the leaf extract of Yer Ligarba (YLL).

FIGURE 8

PCA biplot illustrating sample clustering based on phytochemical and enzymatic profiles. TPC refers to total phenolic content, TFC to total flavonoid content, and TTC to total tannin content. DPPH^•+ and ABTS^•+ represent radical scavenging activities assessed by DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and ABTS (2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) assays, respectively. α‐Glucosidase and α‐amylase indicate enzyme inhibition activities related to carbohydrate metabolism. AChE and BChE refer to acetylcholinesterase and butyrylcholinesterase inhibition activities, respectively. CGA denotes chlorogenic acid, while Quinic A. represents quinic acid.

FIGURE 9

Correlation matrix among phytochemical contents, antioxidant activities, and enzyme inhibition parameters. TPC refers to total phenolic content, TFC to total flavonoid content, and TTC to total tannin content. DPPH^• and ABTS^•+ represent radical scavenging activities assessed by DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and ABTS (2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) assays, respectively. α‐Glucosidase and α‐amylase indicate enzyme inhibition activities related to carbohydrate metabolism. AChE and BChE refer to acetylcholinesterase and butyrylcholinesterase inhibition activities, respectively. CGA denotes chlorogenic acid content, while Quinic A. represents quinic acid content. DLB corresponds to the branch of Dal Ligarba, DLL to the leaf of Dal Ligarba, DLF to the fruit of Dal Ligarba, YLB to the branch of Yer Ligarba, YLL to the leaf of Yer Ligarba, and YLF to the fruit of Yer Ligarba.