Inhibitory effect of arabinoxylan oligosaccharides from Plantago ciliata Desf. seeds on a-amylase and a-d-glucosidase and the inhibition kinetics

The urgent need to tackle the significant public health challenge of diabetes mellitus requires a prompt focus on the exploration of novel and effective antidiabetic medications with limited side effects. The primary objective of this study was to examine the influence of the partial acid hydrolysis of a polysaccharide derived from Plantago ciliata Desf. seeds into oligosaccharides on its antihyperglycemic activity. To achieve this, the resultant oligosaccharides were assessed for their ability to inhibit two enzymes involved in carbohydrate hydrolysis, namely alpha-amylase and alpha-d-glucosidase. Furthermore, the investigation extended to enzyme kinetics analysis to elucidate the inhibition mechanism. The study also evaluated the oligosaccharides' resistance to digestion through in vitro analysis. The results revealed that the arabinoxylan oligosaccharides derived from P. ciliata seeds (AXOPCs) exerted significant inhibitory effects on alpha-amylase and alpha-d-glucosidase enzymes, with IC50 values of 2.36 +/- 0.38 and 1.19 +/- 0.16 mg/mL, respectively, whereas acarbose (used as the reference in both tests) presented lower IC50 values of 0.34 +/- 0.18 and 0.703 +/- 0.27 mg/mL, respectively. These oligosaccharides act as effective non-competitive inhibitors of a-amylase and exhibit non-competitive inhibition of a-d-glucosidase, with inhibition constant values of 5.47 and 2.49 mM, respectively. When the AXOPCs were successfully tested for use as non-digestible oligosaccharides, they showed a maximum digestibility percentage of 22.8%, whereas the value was 51.3% for the fructooligosaccharides used as a reference. These results are consistent with the traditional use of P. ciliata seeds in medicine for reducing blood sugar levels. To build on these results, in vivo experiments to assess the use of the AXOPCs as a new natural and healthy drug should be performed.

Automated summary

This study investigates the impact of partial acid hydrolysis on the antihyperglycemic activity of a polysaccharide derived from Plantago ciliata seeds. The results demonstrate that the resulting oligosaccharides exhibit significant inhibitory effects on alpha-amylase and alpha-D-glucosidase enzymes and act as non-competitive inhibitors. Additionally, these oligosaccharides show resistance to digestion, suggesting their potential as a natural and healthy drug for reducing blood sugar levels.