Saponins from the rhizomes of Polygonatum nodosum Hua and their chemotaxonomic significance

Polygonatum sibiricum saponin Exerts Beneficial Hypoglycemic Effects in Type 2 Diabetes Mice by Improving Hepatic Insulin Resistance and Glycogen Synthesis-Related Proteins

Type 2 diabetes mellitus (T2DM) is a systemic metabolic disorder characterized by insulin deficiency and insulin resistance. Recently, it has become a significant threat to public health. Polygonatum sibiricum saponin (PSS) has potential hypoglycemic effects, but its specific mechanism needs further study. In this study, PSS significantly decreased the level of blood glucose, water intake, and the organ index in diabetic mice. Meanwhile, PSS effectively reduced the content of total triglyceride (TG), total cholesterol (TCHO), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in the blood, and increased the content of high-density lipoprotein cholesterol (HDL-C). This suggests that PSS could reduce the content of blood lipids and initially improve the damage of hepatocytes. We found that PSS alleviated hepatic insulin resistance, repaired islet beta cells, and enabled insulin to play its biological role normally. It also improved oral glucose tolerance and abated serum lipopolysaccharide (LPS) and glycosylated hemoglobin (HbA1c) levels in T2DM mice. Furthermore, studies have found that PSS increased the content of phosphorylated protein kinase B (AKT), thereby promoting the effect of glucose transporter 4 (GLUT-4), and activating glycogen synthase kinase 3beta (GSK-3β) and glycogen synthase (GS) proteins to promote hepatic glycogen synthesis. Finally, we found that PSS could promote the growth of beneficial bacteria such as Bifidobacterium and Lactobacillus, reduce the growth of harmful bacteria such as Enterococcus and Enterobacter, and preliminarily improve the composition of important bacteria in the intestine. These studies indicate that PSS has an excellent hypoglycemic effect, which provides a potential new treatment for T2DM and guidance for more in-depth research.

Structural Characterization of a Polygonatum cyrtonema Hua Tuber Polysaccharide and Its Contribution to Moisture Retention and Moisture-Proofing of Porous Carbohydrate Material

Porous carbohydrate materials such as tobacco shreds readily absorb moisture and become damp during processing, storage, and consumption (smoking). Traditional humectants have the ability of moisture retention but moisture-proofing is poor. Polygonatum cyrtonema Hua polysaccharide (PCP 85−1−1) was separated by fractional precipitation and was purified by anion exchange and gel permeation chromatography. The average molecular weight (Mw) of PCP 85−1−1 was 2.88 × 10³ Da. The monosaccharide composition implied that PCP 85−1−1 consisted of fucose, glucose, and fructose, and the molar ratio was 22.73:33.63:43.65. When 2% PCP 85−1−1 was added to tobacco shreds, the ability of moisture retention and moisture-proofing were significantly enhanced. The moisture retention index (MRI) and moisture-proofing index (MPI) increased from 1.95 and 1.67 to 2.11 and 2.14, respectively. Additionally, the effects of PCP 85−1−1 on the aroma and taste of tobacco shreds were evaluated by electronic tongue and gas chromatography–mass spectrometry (GC-MS). These results indicated that PCP 85−1−1 had the characteristics of preventing water absorption under high relative humidity and moisturizing under dry conditions. The problem that traditional humectants are poorly moisture-proof was solved. PCP 85−1−1 can be utilized as a natural humectant on porous carbohydrates, which provides a reference for its development and utilization.