Structural characterization and anti-ageing activity of polysaccharide from Exocarpium Citrulli

In this investigation, we have effectively extracted and characterized a new Exocarpium Citrulli polysaccharide (ECP-2) with a molecular weight of 1.67 × 106 Da using hot water extraction and ethanol precipitation techniques. Analysis was performed using high performance gel permeation chromatography, ion chromatography, Fourier transform infrared spectroscopy, nuclear magnetic resonance, and scanning electron microscopy. ECP-2 is primarily composed of galactose (32.32%), arabinose (25.42%), and mannose (19.75%). Fuc, Rha, Ara, Gal, Glc, Man, and GalA molar ratios in ECP-2 is 4.65:1.50:25.42:32.32:5.78:19.75:10.57. Based on structural studies, the primary sugar residues of ECP-2 are T-α-L-Araf-(1→, →5)-α-L-Araf-(1→, T-α-D-Manp-(1→ and →3,6)-β-D-Galp-(1→. Furthermore, the anti-aging effect of ECP-2 in D-galactose model mice, while the results indicate that ECP-2 significantly enhances the activities of superoxide dismutase, glutathione peroxidase, and catalase in D-galactose model control mice. Additionally, ECP-2 effectively eliminated the lipid peroxidation product malondialdehyde, thereby restoring normal growth of the mice by regulating their defense mechanism. In conclusion, the polysaccharides of Exocarpium Citrulli, particularly ECP-2, may be appropriate for use in natural medicines and functional foods to halt or slow the aging process.