Investigation of the Effects of Curcumin on GLP1-R in Liver Tissue of Diabetic Rats

The study was designed to investigate the effect of curcumin, known for its antidiabetic properties, on the immunohistochemical localization and gene expression of glucagon-like peptide-1 receptor (GLP-1R) in the liver tissues of experimental diabetic rats using reverse transcription polymerase chain reaction (RT-PCR). For this, 24 Sprague–Dawley rats were divided into four groups—control, sham, diabetic, and diabetic + curcumin groups. The control group received no treatment, and 50 mg/kg streptozotocin was administered to the rats in the diabetic and diabetic + curcumin groups received 50 mg/kg streptozotocin. Once diabetes had been established, 100 mg/kg of curcumin was administered intraperitoneally to rats in the diabetic + curcumin group for a period of 21 days. Thesham group was administeredintraperitoneal ethanol and isotonic sodium chloride solution. At the ends of the experiment,tissues were subjected to histological and immunohistochemical examination to ascertain the localization of GLP-1R. Additionally, RT-PCR was employed to determine the levels of GLP-1R gene expression.The histological examinations revealed that the tissue samples from the control and sham groups exhibited a normal histological structure. In contrasr, the diabetic group displayed a range of degenerative changes, including enlargement of the sinusoidal wall enlargement and vacuolization of the hepatocytes. Furthermore, these degenerative findings were mitigated in the diabetic + curcumin group. In the immunohistochemical examinations, the majority of hepatocytes surrounding the vena centralis, as well as some endothelial, and some Kupffer cells,exhibited positively for GLP-1R. The diabetic group exhibited reduced immunoreactivity, while the diabetic + curcumin group demonstrated elevated immunoreactivity compared to the diabetes group. With regard to the molecular analysis, the mean expression level was observed to be higher in the diabetes + curcumin group. However, no significant difference in GLP-1R gene expression was identified between the groups. In conclusion, the administration of curcumin was observed to enhance GLP-1R expression in the liver of the rats with diabetes. Given that GLP-1R is a targets for diabetes treatment, curcumin can be used as a viable therapeutic agent for treating diabetes and alleviating its complications.