Ultrasound-Microwave Combined Extraction of Novel Polysaccharide Fractions from Lycium barbarum Leaves and Their In Vitro Hypoglycemic and Antioxidant Activities

Na Quan; Yi-Dan Wang; Guo-Rong Li; Zi-Qi Liu; Jing Feng; Chun-Lei Qiao; Hua-Feng Zhang

doi:10.3390/molecules28093880

Ultrasound-Microwave Combined Extraction of Novel Polysaccharide Fractions from Lycium barbarum Leaves and Their In Vitro Hypoglycemic and Antioxidant Activities

Molecules. 2023 May 4;28(9):3880. doi: 10.3390/molecules28093880.

Authors

Na Quan¹, Yi-Dan Wang¹, Guo-Rong Li², Zi-Qi Liu¹, Jing Feng³, Chun-Lei Qiao¹, Hua-Feng Zhang¹

Affiliations

¹ International Joint Research Center of Shaanxi Province for Food and Health Sciences, Provincial Research Station of Se-Enriched Foods in Hanyin County of Shaanxi Province, College of Food Engineering and Nutritional Science, National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Shaanxi Normal University, Xi'an 710119, China.
² Yinchuan Market Supervision Administration, Yinchuan 750001, China.
³ Agrarian and Technological Institute, Peoples' Friendship University of Russia, Moscow 119991, Russia.

Abstract

Ultrasound-microwave combined extraction (UMCE), gradient ethanol precipitation, chemical characterization, and antioxidant and hypoglycemic activities of Lycium barbarum leaf polysaccharides (LLP) were systematically studied. The optimal conditions for UMCE of LLP achieved by response surface method (RSM) were as follows: microwave time of 16 min, ultrasonic time of 20 min, particle size of 100 mesh, and ratio of liquid to solid of 55:1. Three novel polysaccharide fractions (LLP₃₀, LLP₅₀, LLP₇₀) with different molecular weights were obtained by gradient ethanol precipitation. Polysaccharide samples exhibited scavenging capacities against ABTS and DPPH radicals and inhibitory activities against α-glucosidase and α-amylase. Among the three fractions, LLP₃₀ possessed relatively high antioxidant and hypoglycemic activities in vitro, which showed a potential for becoming a nutraceutical or a phytopharmaceutical for prevention and treatment of hyperglycemia or diabetes.

Keywords: Lycium barbarum leaves; antioxidant capacity; hypoglycemic activity; polysaccharides; ultrasound–microwave combined extraction.

MeSH terms

Antioxidants* / chemistry
Ethanol / analysis
Hypoglycemic Agents / analysis
Hypoglycemic Agents / pharmacology
Lycium* / chemistry
Microwaves
Plant Leaves / chemistry
Polysaccharides / chemistry

Substances

Antioxidants
Hypoglycemic Agents
Polysaccharides
Ethanol

Grants and funding

This research was partially funded by Key Research and Development Program of Shaanxi Province in China (2021YFBT-38-02/2022ZDLSF05-11/2022CGBX-26) and Program of Academician and Expert Workstation in Puer City of Yunnan Province (202305AF150118).