Soraya Sajadimajd - Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran.
Gholamreza Bahrami - Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.

Introduction: Since DNA methylation plays a causal role in β-cell remodeling and development, thus modulation of this epigenetic mechanism is essential in treatment of diabetes. Therefore, this provoked us to examine the effect of a known anti-diabetic agent, an isolated polysaccharide, on the methylation pattern of Ins-۱ and Pax-۴ in diabetic rats. Materials: Here, a polysaccharide fraction was isolated from Rosa canina and analyzed using NMR, FTIR and MS/MS techniques. Diabetes was established by using intraperitoneal injection of STZ in male Wistar rats. After treatment, pancreas was removed and DNA was extracted and bisulfite treated by a DNA methylation kit. PCR and real-time PCR were used to determine the levels of methylated and/or unmethylated Ins-۱ and Pax-۴ genes.Results: The levels of blood glucose and weight body were normalized in diabetic rats exposed to isolated polysaccharide. The level of unmethylated Ins-۱ was upregulated in diabetic rats which is downregulated in metformin and polysaccharide-treated ones. In diabetic rats, the content of methylated Pax-۴ was increased while it was decreased in polysaccharide-treated group. Interestingly, the methylation pattern of Pax-۴ in metformin group was the same as diabetic ones.Conclusion: Data clearly indicated that polysaccharide can reduce the level of blood glucose by modulating the methylation pattern of Pax-۴ and Ins-۱. This study sheds light on the importance of DNA methylation modulation as a promising therapeutic strategy in diabetes.

Diabetes, DNA methylation, Polysaccharide, Rosa canina