Remodeling of Bamboo (Phyllostachys edulis) Shoot Polysaccharides by Monascus purpureus Fermentation Enhances Antioxidant Protection in Caco-2 Cells

TL;DR

Fermenting bamboo shoots with Monascus purpureus changes their sugar structure, boosting antioxidant effects in intestinal cells.

Contribution

Monascus fermentation is shown to structurally remodel bamboo shoot polysaccharides to enhance antioxidant activity.

Findings

Fermentation reduced molecular weight and altered sugar composition of bamboo shoot polysaccharides.

FBSP-1 reduced oxidative stress markers and increased antioxidant enzyme activity in Caco-2 cells.

Structural changes from fermentation improved the functional efficacy of the polysaccharides.

Abstract

Bamboo shoot polysaccharides possess promising bioactivities, but their high molecular weight and complex branched structures limit their functional efficacy. In this study, bamboo (Phyllostachys edulis) shoots were fermented with Monascus purpureus ATCC16426 to obtain a novel neutral polysaccharide (FBSP-1). Monosaccharide composition analysis indicated that FBSP-1 comprised glucose (Glc), xylose (Xyl), arabinose (Ara), galactose (Gal), and mannose (Man). Glycosidic linkage and nuclear magnetic resonance (NMR) spectroscopy data revealed that the backbone of FBSP-1 mainly consisted of →2)-α-Manp-(1→, →4)-α-Glcp-(1→, →3)-β-Xylp-(1→, →3)-α-Araf-(1→ and →2)-α-Araf-(1→. Compared with unfermented polysaccharide BSP-1, fermentation markedly altered the monosaccharide profile, increasing Glc, Xyl and Man, decreasing Ara and Gal, and reducing the molecular weight. In H2O2-treated Caco-2 cells, FBSP-1 significantly alleviated oxidative damage by reducing intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels, while enhancing the activities of superoxide dismutase (SOD) and glutathione reductase (GR), demonstrating pronounced antioxidant protective effects. Overall, this study demonstrates that Monascus fermentation is an effective strategy for the structural remodeling of bamboo shoot polysaccharides, enabling the enhancement of their antioxidant functionality and supporting their potential application as functional ingredients in plant-based antioxidant foods.

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