An Optimum Dose of Olive Leaf Extract Improves Insulin Receptor Substrate-1, Tyrosine Kinase, and Glucose Transporters, While High Doses Have Genotoxic and Apoptotic Effects

Abstract

Type 2 diabetes is the most common type of diabetes. Conventionally many drugs are used for the treatment of diabetes such as biguanides, sulfonylureas, meglitinides, etc. But the desired effective treatment is still not to be achieved. So researches are going on for the development of effective alternative therapy against diabetes. Olive leaves are traditionally used in the treatment of the disease. However, studies on its mechanism of action are not yet enough. The aim of this study was to investigate whether olive leaf extract (OLE) improves insulin receptor substrate-1 (IRS-1), tyrosine kinase (TK), GLUT-2, and GLUT-4. Oleuropein levels were analyzed from OLE obtained by using four different solvents, and the highest content of methanol extract was selected for the study. Different concentrations of OLE (2.5 to 320 μg/mL) were incubated with hepatocellular carcinoma (HepG2) cells for 24 hours. After incubation, cell viability was assessed based on luminometric ATP cell viability assay kit. Intracellular reactive oxygen species (ROS) generating level was detected using 2,7dichlorodihydrofluorescein-diacetate (H 2 DCF-DA) fluorescent probes. Apoptosis was evaluated by acridine orange/ethidium bromide double staining method. Genotoxicity was evaluated by alkaline single cell gel

Effects of 1,25 Dihydroxyvitamin D3 on Human Retinal Pigment Epithelial Cell Lines

“…= 488/525 nm, the fluorescence plate reader (Varioskan Flash Multimode Reader, Thermo, Waltham, MA) was used. The values were reported as % relative fluorescence compared to the control [13].…”

Oleuropein and Hydroxytyrosol as Antidiabetics: A Review on Extraction Method, Effectiveness and Toxicity Effect

“…SGLT2 inhibitors (dapagliflozin) are thought to help obese people lose weight and lower their systolic blood pressure (14). On the other hand, GLP-1 RA (liraglutide) control blood sugar and weight loss better than a DPP-4 inhibitor and cause less hypoglycaemia (15). Oleuropein and hydroxytyrosol (Figure 1) are secondary metabolites in olive fruit and leaves (Olea uropeae), belonging to the Oleaceae family (16).…”

In silico Study to Optimize the Dosage of Oleuropein with Metformin in Diabetes Management

“…The effect of oleuropein on GLUT4 enrichment levels in human cells at an optimum dose of 10 g/mL in human hepatocellular carcinoma cells was investigated by Kocyigit et. al. in an interesting in vitro study [58]. To get the finest outcomes, though, it's crucial to figure out the best and safest dose of OLE.…”