Deglet Noor date derived polysaccharides lower blood glucose levels and modulate the gut microbiota in a streptozotocin-induced type-1 diabetic mouse model

Abstract

Diabetes mellitus is a chronic metabolic disorder marked by insulin deficiency and hyperglycemia. At present, pharmacotherapy involving synthetic diabetic agents is widely used, but it comes with side effects. In contrast, natural compounds like polysaccharides show promising anti-diabetic activity and are increasingly used alongside conventional therapies, especially in developing countries. This study investigated the effects of crude polysaccharides from Deglet Noor dates (DNP) on type 1 diabetes induced by streptozotocin (STZ) in male BALB/c mice. DNP was extracted using water, deproteinized, and precipitated with ethanol. Monosaccharide composition was analyzed using high-performance liquid chromatography (HPLC), and diabetic mice received oral DNP supplementation for five weeks. Body weight, blood glucose, food and water intake, cytokine expression, histology, and gut microbiota composition were assessed. HPLC analysis identified mannose, rhamnose, glucose, and galactose as key monosaccharides in DNP. Treatment with DNP significantly reduced blood glucose levels, improved body weight, and normalized food and water intake. It enhances glucose tolerance, insulin sensitivity, and insulin levels while reducing serum lipids, triglycerides, and free fatty acids. DNP also improved pancreatic morphology, restoring the islet structure and increasing cellular density. Pro-inflammatory cytokines (TNF-α, IL-1β, and IL-17) were reduced, while IL-10 levels increased. In the liver, DNP reduced necrosis, inflammation, and oxidative stress, as indicated by lower SOD and MDA levels. Colon tissue showed restored goblet cells, reduced inflammation, improved crypt structure, and increased mucin-2 expression. Furthermore, DNP reversed STZ-induced gut microbiota dysbiosis, increasing microbial diversity and beneficial bacteria while reducing pathogenic bacteria. In conclusion, DNP alleviates diabetes by improving glucose metabolism, insulin sensitivity, and inflammation while restoring pancreatic, liver, and gut health, highlighting its therapeutic potential.