Molecular structure and anti-diabetic activity of a polysaccharide extracted from pumpkin Cucurbita pepo

• Published in: Journal of molecular structure Vol. 1239; p. 130507
• Main Authors: Thanh, Thuy Thi Thu, Quach, Thu Thi Minh, Yuguchi, Yoshiaki, Nguyen, Nu Thi, Van Ngo, Quang, Van Bui, Nguyen, Kawashima, Sugumi, Ho, Cuong Duc
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.09.2021
• Subjects: Anti-diabetic activity; Polysaccharide; Pumpkin; Small angle X-ray scattering; Anti-diabetic activity; Polysaccharide; Small angle X-ray scattering; Pumpkin
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2021.130507

•A polysaccharide was extracted and purified from pumpkin.•It was composed of α-(1→6)-glucan branched at C3 and α-(1→4)-galactan.•It had a local rod-like conformation and chain aggregation was observed.•It showed significant anti-diabetic activity. In this work, structure and anti-diabetic effect of a polysaccharide (PP-PE) obtained by hot-water extraction from Cucurbita pepo was studied. The results showed that PP-PE was composed of α-(1→6)-glucan branched at C3 position and α-(1→4)-galactan. The polysaccharide molecule had a local rod-like conformation in solution with the cross-sectional radius of gyration of 0.27 nm and the chain aggregation was also observed from SAXS measurements. For alloxan-diabetic mice, blood glucose level was decreased by 29.8 % after 7 days PP-PE treatment at a dose of 100mg/kg/day. The histological examination indicated that degeneration and necrosis of pancreas tissues were observed in diabetic mice, however, histopathological changes were restored to near normal by PP-PE treatment. PP-PE also showed α-glucosidase and α-amylase inhibited activities with an IC50 value of 110.32±7.08 mg/mL and 103.06±1.60 mg/mL, respectively.