Abstract:The main chemical components of Polygonatum from six different origins, Yunnan and Guangxi (Polygonatum kingianum), Hunan and Anhui (Polygonatum cyrtonema), and Heilongjiang and Liaoning (Polygonatum sibiricum) were compared. Their hypoglycemic properties were analyzed based on the inhibition rates against α-glucosidase and α-amylase and the glucose dialysis delay indices of their extracts. A screened Polygonatum was incubated in vitro with the feces of diabetic mice, and through 16S rDNA sequencing, the regulation of the composition and structure of the intestinal flora of diabetic mice were analyzed. There were significant differences (p<0.05) among the components of the Polygonatum from different origins. The inhibitory rates of the aqueous extract of Guangxi Polygonatum kingianum were 98.36% against α-glucosidase and 91.85% against α-amylase, which were significantly higher than those of other origins (p<0.05). The glucose dialysis indices exhibited an increasing trend. After comprehensive analysis, Polygonatum kingianum from Guangxi was selected for in vitro incubation. The abundances of beneficial bacteria such as Proteobacteria and Bifidobacterium increased, whilst the abundances of harmful bacteria such as Prevotellaceae_NK3B31_group and Ruminococcus_2 decreased. These results revealed that the water extract of Guangxi Polygonatum kingianum can significantly improve the diversity of the intestinal flora of diabetic mice, and adjust the structure of the intestinal flora. The study provides a theoretical reference for the regional differences in the chemical composition of Polygonatum and its hypoglycemic function and regulatory effect on the intestinal flora in diabetic mice.
