Encapsulation of cinnamon oil in whey protein counteracts the disturbances in biochemical parameters, gene expression, and histological picture of the liver and pancreas of diabetic rats.

This study aimed to evaluate the protective role of encapsulated cinnamon oil emulsion (COE) in whey protein concentrate (WPC) against the disturbance in lipid profile, oxidative stress markers, and gene expression in streptozotocin (STZ)-treated rats. COE was analyzed using GC-MS, and the emulsion was prepared and characterized. In the in vivo study, six groups of male rats were treated orally for 4 weeks, including the control group, the group treated with STZ (D-rats), the groups received a low or high dose of COE (200 or 400 mg/kg B.w.), and the D-rats groups received COE at the low or high dose. Blood and tissue samples were collected after the end of the treatment period for biochemical, genetical, and histological analyses. The GC-MS results revealed that the major components of the oil were cinnamaldehyde, 1,8 cineole, acetic acid, 1,7,7-trimethylbicyclo[2.2.1]hept2yl ester, α-Pinene, and α-Terpineol. The size, zeta potential, and polydispersity index (PDI) of COE were 240 ± 1.03 nm, - 7.09 ± 0.42, and 0.36, respectively. The in vivo results revealed that COE at the two tested doses improved the levels of glucose, insulin, amylase, lipid profile, hepatic MDA, SOD, and GSH. COE also downregulated hepatic GLU2, FAS, SREBP-1c, and PEPCK gene expression and upregulated IGF-1 mRNA expression in diabetic rats in a dose-dependent manner. Moreover, COE improved and the histological picture of the liver and pancreas. It could be concluded that COE overcomes the disturbances in biochemical, cytological, and histopathological changes in D-rats via the enhancement of antioxidant capacity; reduces the oxidative stress; modulates the concerned gene expression; and may be promising to develop new drugs for diabetic treatment.