Extraction，Separation and Hypoglycemic Activity Analysis of Polysaccharides from Brassica rapa
10.13422/j.cnki.syfjx.20260162
- VernacularTitle:芜菁多糖的提取分离及降糖活性分析
- Author:
Mengyu HOU
1
;
Ruina XU
2
;
Qingsong LI
1
;
Shaoxuan LI
2
;
Xinying MA
2
;
Yaohui YE
1
Author Information
1. Jiangxi Provincial Education Department Key Laboratory for Application of Key Technologies in Drug Screening for Inflammatory Diseases and Phlegm Syndrome，Nanchang Medical College，Nanchang 330052，China
2. Jiangxi University of Chinese Medicine，Nanchang 330004，China
- Publication Type:Journal Article
- Keywords:
Brassica rapa polysaccharides;
semi-bionic extraction method;
structural characterization;
hypoglycemic activity;
process optimization;
diabetes mellitus
- From:
Chinese Journal of Experimental Traditional Medical Formulae
2026;32(10):219-228
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo optimize the extraction method for polysaccharides from turnip（Brassica rapa）， and analyze and evaluate the primary structure of the isolated and purified turnip polysaccharide fraction（BP-1） and its hypoglycemic effects in diabetic zebrafish. MethodsTaking polysaccharide yield as the evaluation index， a semi-bionic extraction method was employed. Single-factor experiments and Box-Behnken response surface methodology were used to investigate three factors of solid-to-liquid ratio， extraction time and extraction temperature， in order to optimize the extraction process. BP-1 was isolated and purified using the Sevage method and DEAE-52 cellulose column chromatography. Structural characterization of the turnip polysaccharides was performed using ultraviolet-visible spectrophotometry（UV）， gas chromatography-mass spectrometry（GC-MS）， Congo red assay， and Fourier-transform infrared spectroscopy（FT-IR） to determine purity， monosaccharide composition， triple-helix structure， and functional groups. The microstructure of the polysaccharides was observed using scanning electron microscopy（SEM） and atomic force microscopy（AFM）. Zebrafish were divided into the blank group（adding E3 medium）， and BP-1-1， BP-1-10， BP-1-50， BP-1-200， BP-1-1 000 groups（adding BP-1 solutions at concentrations of 1， 10， 50， 200， 1 000 mg·L-1， respectively）， and zebrafish embryos were subjected to a 96-hour exposure experiment. The maximum tolerated concentration of BP-1 in zebrafish was determined by evaluating its effects on phenotype， survival rate， malformation rate， and heart rate. Experimental animals were randomly divided into the blank group， model group， BP-1-10 group（10 mg·L-1）， BP-1-50 group（50 mg·L-1）， and BP-1-200 group（200 mg·L-1）. The blank group was cultured in E3 medium， the model and treatment groups were induced to establish a diabetic model in 4 day-post-fertilization（dpf） zebrafish embryos using 10 g·L-1 of glucose combined with 500 µmol·L-1 of alloxan. The treatment groups received corresponding doses of BP-1 solution， while the blank and model groups received an equal volume of saline. Glucose and insulin（INS） levels were measured using enzyme-linked immunosorbent assay（ELISA） kits， the effects on the liver were observed by hematoxylin-eosin（HE） histopathological sections. The mRNA expression levels of glucagon（Glucagon）， insulin（Insa）， and phosphoenolpyruvate carboxykinase 1（PCK1） were detected with real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）. ResultsThe optimized extraction conditions were determined as follows：solid-to-liquid ratio of 1∶40（g·mL-1）， extraction time of 66 min， and extraction temperature of 79 ℃. Under these conditions， the yield of turnip polysaccharides was （10.34±0.96）%. UV analysis indicated that BP-1 contained no proteins or nucleic acids， GC-MS analysis revealed that BP-1 consisted of six monosaccharides（arabinose， rhamnose， ribose， mannose， galactose and glucose）. Congo red assay indicated that the molecular conformation did not exhibit a triple-helix structure， FT-IR analysis showed the presence of α-glycosidic bonds and uronic acids， SEM analysis revealed an irregular flaky structure with a flat and smooth surface， AFM analysis suggested that the aggregated structure might be formed by the entanglement of molecular chains and intramolecular hydrogen bonding. The maximum tolerated concentration of BP-1 in zebrafish over 96 h was determined to be 200 mg·L-1. Pharmacodynamic results showed that， compared with the blank group， the model group exhibited significantly increased glucose levels and significantly decreased INS levels（P<0.01）. Compared with the model group， the BP-1-50 group significantly reduced glucose levels and increased INS levels（P<0.05）. Histopathological examination of liver tissue revealed that various doses of BP-1 had a certain reparative effect on damaged liver tissue. The liver tissue structure in the BP-1-200 group was nearly normal， with hepatocytes appearing plump. Real-time PCR results showed that， compared with the blank group， the model group exhibited significantly upregulated mRNA expressions of Glucagon and PCK1， and significantly downregulated mRNA expression of Insa（P<0.01）. Compared with the model group， the BP-1-50 and BP-1-200 groups showed significantly downregulated mRNA expressions of Glucagon and PCK1， and significantly upregulated mRNA expression of Insa（P<0.01）. ConclusionThe semi-bionic extraction method for turnip polysaccharides yields a high extraction rate， is simple to operate， has low costs， making it suitable for large-scale industrial production. BP-1 consists of six monosaccharides， contains α-glycosidic bonds and uronic acids， exhibits hypoglycemic activity， and provides a certain protective effect on the liver of alloxan-induced diabetic model zebrafish.
