Abstract
Objective: A questionnaire study was conducted to evaluate the applications of plants and herbal products consumed by diabetic patients for the treatment of chronic health conditions. Evaluation of the questionnaire confirmed that olive leaf is one of the most used herbs in the treatment of diabetes, in line with its traditional use in the literature. In vitro biological activity studies were performed to determine whether different olive leaf samples have antidiabetic effects. Additionally, the major component oleuropein was quantitively determined in the samples.
Material and Method: The established survey was firstly approved by the ethics committee at Gazi University then the survey was conducted at the University Hospital, Department of Endocrinology between January 2021, and July 2021. Based on the result of the survey, pharmacognostic analyses, chromatographic analyses, and inhibition on diabetes-related enzymes (α-amylase, α-glucosidase, and aldose reductase) were performed on the samples of olive leaves collected from nature, obtained from herbalists, markets and pharmacies.
Result and Discussion: Evaluation of the survey revealed that the patients mostly used cinnamon (29.3%) and olive leaves (21.7%) for the treatment of diabetes, and these plants were generally obtained from herbalists (51.7%). The study findings showed that aqueous and ethanolic extracts prepared from olive leaf samples contained 190.3-374.3 mg/g oleuropein. The amount of oleuropein in the ready-made olive leaf extract from herbalists was found to be much lower (50.9 mg/g) than the other olive leaf extracts. When the enzyme inhibition activity assays were evaluated, it was determined that all olive leaf samples had inhibitory effects on α-amylase, α-glucosidase, and aldose reductase enzymes. All olive leaf samples, including teas prepared by the public at home with water, were found to have capacity to decrease the blood level in other words antidiabetic activities in vitro. The oleuropein contents detected in this study once again revealed the importance of meticulous examination in herbal products.
Ethical Statement
Gazi University Ethics Committee (E-77082166-604.01.02-35354)
Supporting Institution
Gazi University Scientific Research Projects Unit
Thanks
This study was carried out as a 'specialist thesis' in the Department of Pharmacognosy. We thank Gazi University Scientific Research Projects Unit for supporting this thesis. (TEU-2022-7381)