Acidic polysaccharide from corn silk: Structural & conformational properties and hepatoprotective activity

Area of Science:

• Biochemistry
• Pharmacology
• Natural Products Chemistry

Background:

• Corn silk, a byproduct of maize cultivation, is rich in polysaccharides.
• Acidic polysaccharides possess diverse biological activities, including potential therapeutic applications.
• Investigating novel bioactive compounds from natural sources is crucial for drug discovery.

Purpose of the Study:

• To characterize the structure and conformational properties of a novel acidic polysaccharide from corn silk, designated CSP-50E.
• To evaluate the in vitro hepatoprotective activity of CSP-50E against ethanol-induced liver injury.
• To elucidate the underlying mechanisms of CSP-50E's hepatoprotective effects.

Main Methods:

• Structural characterization using methylation analysis.
• Conformational analysis via High-Performance Size-Exclusion Chromatography (HPSEC).
• In vitro assessment of hepatoprotective effects on HL-7702 cells exposed to ethanol, measuring IL-6, TNF-α, AST, and ALT levels.
• Investigation of apoptosis pathways, including caspase cascade and mitochondrial pathways.

Main Results:

• CSP-50E, with a molecular weight of 1.93 × 10^5 g/mol, is composed of Gal, Glc, Rha, Ara, Xyl, Man, and uronic acid.
• Methylation analysis revealed CSP-50E primarily contains T-Manp, 4-substituted-D-Galp/GalpA, and 4-substituted-D-Glcp residues.
• CSP-50E exhibited a random coil conformation in aqueous solution.
• CSP-50E significantly reduced IL-6, TNF-α, AST, and ALT levels, protecting against ethanol-induced liver cell damage.
• The protective mechanism involves the caspase cascade and the mitochondrial apoptosis pathway.

Conclusions:

• CSP-50E is a novel acidic polysaccharide from corn silk with significant hepatoprotective properties.
• Its protective effects are mediated through the modulation of inflammatory cytokines and apoptosis pathways.
• CSP-50E holds potential for the development and utilization of corn silk as a source of therapeutic agents.