Antioxidant, antidiabetic effects and polyphenolic contents of propolis from Siirt, Turkey

Abstract

Propolis, a natural product collected by honeybees from various plant sources, has gained significant attention due to its diverse bioactive compounds and potential therapeutic properties. To further explore its contents and biological activities, this study aimed to analyze the phenolic compounds in Siirt propolis extracts obtained using different solvents, namely ethanol, water, and ethanol-water mixtures. The primary objective of this research was to investigate the phenolic profile, as well as the antidiabetic and antioxidant activities of the propolis extracts. Chemical profiling of extracts was performed using LC-MS/MS. The antioxidant potential of the propolis extracts was evaluated through free radical scavenging methods, including DPPH and ABTS assays. As a result of these analyses, propolis extracts showed moderate radical scavenging potential with 13.86%-35.72% for DPPH and 33.62%-62.50% for ABTS at a concentration of 30 μg mL^-1, respectively. This radical scavenging potential of the extracts sheds light on its ability to combat oxidative stress, which is implicated in the development of diabetes, and its potential effects on cellular health. Additionally, the study assessed the antidiabetic properties of the propolis extracts by examining their inhibition effects on α-amylase and α-glycosidase enzymes. Extracts with high phenolic content showed a high inhibitory effect against α-glucosidase with an IC₅₀ of 5.72 ± 0.83 μg mL^-1. This research provided significant findings regarding the potential use of propolis in the treatment of diabetes and related metabolic disorders.

Keywords: Propolis; antioxidant activity; radical scavenging; α‐amylase; α‐glycosidase.

FIGURE 1

Major phenolic compounds according to LC–MS/MS results (μg mL⁻¹).

FIGURE 2

A correlation heatmap based on assessing the relationship between variables. The number in brackets in each cell represents the p‐values and the other represents the R‐value. R‐values are a measure of correlation strength and range from −1 to +1.