Ultrasound-assisted extraction, purification, sulfation of Perilla leaves polysaccharide and hypoglycemic and hypolipidemic activities

Perilla leaves are a common traditional medicinal and edible crop, in order to further develop its medicinal value, a neutral polysaccharide was extracted and analyzed on its structure and studied on sulfation modification. After purification by different column chromatography, the optimal process for sulfation modification of PLP-2-1 was determined, and S-PLP-2-1 was prepared. The potential structural framework and molecular weight of PLP-2-1 were determined by HPLC, methylation analysis, and NMR techniques, while sulfated modified S-PLP-2-1 maintained a high degree of structural similarity with it. Particle size, Zeta potential, infrared spectroscopy, and NMR analysis confirmed the presence of sulfate groups in S-PLP-2-1, while thermogravimetric and rheological analyses provided support for the development and utilization of the two polysaccharides. After determined the safe concentration range in vitro, the antioxidant and hypoglycemic activities of PLP-2-1 and S-PLP-2-1 were measured. Besides, the effects on the levels of TC, TG, HDL-C, and LDL-C in OA induced high-fat HepG2 cells of both polysaccharides were determined. The results showed that the various activities of S-PLP-2-1 were significantly improved after sulfation modification. Therefore, PLP-2-1 and S-PLP-2-1 may be potential drugs for anti-glycolipid metabolism disorders.