Structural Characteristics of Brassica rapa L. Polysaccharide and Its Bioactivity on Alcoholic Liver Injury

Abstract

In this study, polysaccharides were extracted from Brassica rapa L. (BRL) using ultrasonication-assisted extraction. The purified Brassica rapa L. polysaccharide (BRLPP) was structurally characterized, and its protective effects against alcoholic liver disease (ALD) were investigated. First, response surface methodology (RSM) was employed to optimize the extraction conditions, which were determined as a material-to-liquid ratio of 1:30 and ultrasonication at 200 W for 3 h, yielding BRLP at 6.90% ± 0.39%. Subsequent structural analysis revealed that BRLPP had an average molecular weight of 5.72 × 10⁴ Da and was primarily composed of glucose and arabinose in a molar ratio of 94.29:3.06. GC-MS analysis further identified three major glycosidic linkage patterns: →4)-G1cp-(1→, →4,6)-G1cp-(1→, and →3,4) - G1cp-(1→. BRLPP exhibited potent antioxidant activity, demonstrating significant scavenging effects on DPPH and ABTS⁺ radicals. To evaluate its hepatoprotective potential, a zebrafish ALD model was established using 2% ethanol exposure. The results indicated that BRLPP effectively attenuated ethanol-induced liver damage by reducing serum ALT and AST levels. Additionally, BRLPP mitigated oxidative stress by modulating the activities of key biomarkers, including SOD, MDA, and GSH-Px. These findings suggest that BRLPP possesses notable antioxidant and hepatoprotective properties, highlighting its potential as a bioactive ingredient in functional foods for ALD prevention and treatment.

Note:
Funding declaration: This research was supported by the Key R&D Program of Xinjiang (2022B02037), Mount Taishan Scholar Young Expert, and key R & D Program of Shandong Province (2024SFGC0401), Xinjiang Uygur Autonomous Region "Tianchi Talent" Training Plan Project (2023).

Conflict of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical Approval: This experiment has been approved by the ethics committee of the corresponding authors' research institute.

Keywords: Brassica rapa, Polysaccharide, Extraction Process, Hepatoprotective activity