Anti-diabetic effect of a novel oligosaccharide isolated from Rosa caninavia via modulation of DNA methylation in Streptozotocin-diabetic rats.

BACKGROUND Diabetes mellitus (DM) is a well-known clinical entity with various late complications. There is a surge of research aiming to use the medical herb in the management of DM. OBJECTIVE This study aimed to investigate whether the alleviation of DM by an isolated compound from Rosa canina is mediated by DNA methylation in STZ-diabetic rats. METHODS Sixty adult Wistar male rats were classified into control, diabetic and treatment groups. Rats were treated with STZ (40 mg/kg), metformin (500 mg/kg), and oligosaccharide fraction (OF; 10, 20 and 30 mg/kg) isolated from Rosa canina. DNA was extracted from the blood and pancreas to determine DNA methylation using the Global DNA Methylation kit. The expressions of DNA methyltransferases (Dnmts), PDX1, Ins1, GCK and PTP1B2 were determined by using qRT-PCR. RESULTS The significant blood glucose-lowering potential of OF was associated with a reduced level of global DNA methylation (p < 0.05). The expression levels of Dnmts 1 and 3α increased in the pancreas and blood from diabetic rats compared to control group which declined by OF treatment (p < 0.05). Paradoxically, the expression of Dnmt 3β augmented in the pancreas and blood of OF group compared to diabetic ones (p < 0.05). Besides, the expressions of Pdx1, PTP1B2, Ins1 and GCK increased in OF-treated rats compared to diabetic groups. CONCLUSION Results revealed that DNA methylation plays a causal role in the effectiveness of the isolated OF. Furthermore, the possible regenerative potential of oligosaccharide in diabetic rats may have contributed to the modulation of DNA methylation.