Extraction, characterization of polysaccharides from lycium barbarum and its effect on bone gene expression in rats

In this study, water-soluble polysaccharides were isolated from dried fruits of lycium barbarum. Gas chromatography–mass spectrophotometer (GC–MS) and Fourier-transform infrared (FT-IR) spectroscopy were used to characterize the compounds in polysaccharides from lycium barbarum (LBP). GC–MS analysis revealed that glucose and mannose were the main monosaccharides of LBP. Xylose, galactose, arabinose and galactose were detected in trace amounts. The Fourier-transform infrared spectra (FT-IR) of LBP revealed typical characteristics of polysaccharides. The pharmacological study indicated that LBP could enhance bone mineral density (BMD) and bone mineral content (BMC) in rats. RT-PCR studies had shown that LBP treatment resulted in increase in the mRNA expression of Col5a2 and Alpl in rat blood. Western blot analyses elicited a decreased Col5a2 and Alpl protein level after 45 days of LBP administration. Taken together, our results provide evidence that LBP increase bone gene expression, bone mineral density (BMD) and bone mineral content (BMC) in ovariectomized rats.