Polysaccharide modification exerts important significance for enhancing biological activity. In the present study, a fructan (AAP70-1) extracted from Anemarrhena asphodeloides Bunge was modified by carboxymethylation and sulfation modifications to obtain carboxymethylated derivatives (CM-AAP70-1s) and a sulfated derivative (S-AAP70-1), which were prepared by the chloroacetic acid-isopropanol and the chlorosulfonic acid-pyridine methods, respectively. Physicochemical characteristics and antioxidant activities in vitro of modified derivatives were determined. The results of degree of substitution (DS) and FT-IR analysis indicated that the carboxymethylated and sulfated groups were introduced successfully. After modifications, the DS of CM-AAP70-1s varied from 0.18 to 0.52 and the molecular weights (Mw) were between 4.50 × 10 3 and 8.65 × 10 3 g/mol. The DS and Mw of S-AAP70-1 were calculated to be 0.61 and 9.76 × 10 3 g/mol, respectively. The assays of the antioxidant properties demonstrated that the modified derivatives exhibited stronger scavenging effects toward DPPH and hydroxyl radicals compared with AAP70-1. These results revealed that the chemical modifications could effectively improve the potential of polysaccharides as oxidation inhibitor.
Juncheng Chen,Lin Li,Xia Zhang,Yuan Zhang,Qingsong Zheng,Meijuan Lan,Bing Li
In this study, an acid polysaccharide (AABP-1B) was extracted from the rhizome of Anemarrhena asphodeloides Bunge and purified using 60 % alcohol precipitation and DEAE-52 cellulose. The molecular weight of AABP-1B was 105 kDa, and it consisted of mannose (Man), rhamnose (Rha), galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara) in a ratio of 6.3:1.3:1.1:0.2:0.4:0.7. Methylation and NMR analyses revealed that the backbone of AABP-1 consists of 4)-β-D-Man p -(1 and 4)-2- O -acetyl-β-D-Man p -(1. In addition, the biological activity assays showed that AABP-1B not only displays potential antioxidant activity but also exhibits the α-glucosidase and α-amylase inhibitory effect. Moreover, AABP-1B enhanced glucose consumption and glycogen synthesis in insulin-resistant (IR) HepG2 cells. These results suggest that AABP-1B has potential hypoglycemic activity.
Ethnopharmacological relevance Within Anemarrhena asphodeloides Bunge (AAB), the pivotal bioactive constituents are identified as Anemarrhena asphodeloides Bunge total saponins (ABS). In traditional pharmacology, ABS has exhibited notable anti-inflammatory, hypoglycemic, and cardioprotective properties. Despite these observed effects, the specific protective mechanisms of ABS against metabolic diseases and improving the endocrine system remain largely uncharted. Aim to study This work intends to shed light on the effects and intrinsic mechanisms of ABS on metabolic diseases. Materials and methods The characterization of ABS components was achieved through High-Performance Liquid Chromatography/Mass Spectrometry (HPLC/MS). To evaluate ABS's anti-inflammatory efficacy, mouse macrophages underwent analysis using the Griess method. Induced differentiation of mouse fibroblasts was assessed through Oil Red O staining. In an obesity model with C57BL/6 N mice, ABS administration prompted measurements of glucose and insulin tolerance. Western blot analysis quantified lipolysis and anti-inflammatory protein expression. Nile red staining gauged body fat content in C. elegans post-ABS treatment. The mechanism of ABS action was elucidated through mRNA sequencing, further validated using RNA interference technology, and nematode mutants. Results ABS showcased the ability to diminish Nitric Oxide (NO) production in inflammatory macrophages and shrink adipocyte lipid droplets. In mice experiments, ABS was effective in alleviating fat accumulation and affecting serum lipid metabolism in diabetic mice. It enhanced oral glucose tolerance and insulin tolerance while increasing lipolysis-associated protein expression. ABS notably reduced fat content in C. elegans . Mechanistically, ABS downregulated NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and monoamine oxidase A (MAOA) expression while enhancing UGT, ilys-2 , and ilys-3 . Lipolysis emerged as a pivotal pathway for ABS in the therapeutic intervention of metabolic diseases. Conclusions Our investigation has revealed that ABS exert a role in combating metabolic diseases by enhancing the body's defense mechanisms. ABS activate the NLRP3-neurotransmitter-visceral adipose pathway in mice, thereby bolstering resistance and diminishing fat accumulation. In C. elegans , ABS downregulated the expression of MAOA, bolstered resistance, and augmented glucuronidase activity, consequently leading to a reduction in fat content.