Impact of Lycium barbarum polysaccharide on the expression of glucagon-like peptide 1 in vitro and in vivo.

Int J Biol Macromol

School of Public Health and Management, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, Yinchuan 750004, China. Electronic address:

Published: January 2023

Several studies showed the efficacy of Lycium barbarum polysaccharide (LBP) in diabetic animals and patients with type 2 diabetes mellitus (T2DM). However, the mechanism of LBP in alleviating T2DM based on glucagon-like peptide 1 (GLP1) has not been suitably elucidated. GLP1 is an important peptide that plays a role in blood glucose homeostasis. Inhibition of sodium/glucose cotransporter 1 (SGLT1) can result in a net increase in GLP1 release. We found that LBP could reduce SGLT1 expression. Thus, the effects of LBP on the first- and second-phase secretion of GLP1 were systematically assessed in vitro using STC1 cells and in vivo using diabetic KK mice. LBP could induce the first-phase secretion of GLP1 by stimulating calcium ion influx in vitro and by inhibiting alpha-glucosidase activity in vivo. Regulation of Gcg gene expression by modulating the Wnt/β-catenin and cAMP/Epac pathways, as well as inhibition of alpha-glucosidase activity, was responsible for the second-phase secretion of GLP1. LBP could stimulate GLP1 secretion; however, dipeptidyl peptidase 4 (DPP4) activated by LBP might offset the second-phase secretion of GLP1. Thus, we suggest considering the simultaneous use of LBP and a DPP4 inhibitor to stimulate slow, continuous GLP1 secretion. Further studies are warranted for in-depth mechanistic information.

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http://dx.doi.org/10.1016/j.ijbiomac.2022.10.176DOI Listing

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