Study on the extraction, purification, partial chemical characterization and anti-alcohol liver injury activity of Mori Fructus polysaccharides

Abstract

Mori Fructus (MF) is a fruit rich in many nutrients. This study focused on the extraction, purification, partial chemical characterization and bioactivity of polysaccharides from MF. Firstly, a water extraction and alcohol precipitation method was used to obtain crude MF polysaccharides (MFPs). After removal of proteins, the crude MFPs were separated and purified by DEAE-cellulose 52, and then 6 MFPs (P₁-MFPs to P₆-MFPs) were obtained. In vitro ethanol dehydrogenase activation activity was used for preliminary screening of anti-alcoholic liver injury activity of these 6 polysaccharides. The results showed that P₁-MFPs and P₂-MFPs had better activities, when the concentration was 5 mg mL⁻¹, and the activation rate reached (58.19 ± 1.3)% and (58.47 ± 1.5)%, respectively. Chemical characterization studies showed that their molecular weight was 316 and 398 kDa, respectively. P₁-MFPs were mainly composed of mannose (11.0%), rhamnose (5.4%), galacturonic acid (4.7%), glucose (33.5%) and xylose (45.5%), meanwhile P₂-MFPs were composed of mannose (7.2%), rhamnose (1.4%), glucose (28.6%) and xylose (62.8%). FT-IR spectroscopy showed that P₁-MFPs and P₂-MFPs contained a pyranose ring and beta glycone bond, both of which had a characteristic absorption peak of polysaccharides. The in vivo activity verification study indicated that P₁-MFPs and P₂-MFPs had the remarkable effect of correcting weight loss and biochemical index (ALT, AST, and TG in serum and MAD, SOD, and GSH-PX in liver) disorder in mice caused by acute alcoholic liver injury. These results revealed that P₁-MFPs and P₂-MFPs had the potential to become precursors to alcohol-induced liver injury or functional food.