Response surface methodology to extraction of dioscoreae polysaccharides and the effects on ratʹs bone quality

The objective of this study was to determine the optimum extraction conditions for dioscoreae polysaccharides. The optimum conditions were evaluated with fractional factorial design and optimized using response surface methodology. The effects of three independent variables, namely extraction time, extraction temperature and ratio of liquid to solid on the yield of dioscoreae polysaccharides were investigated. Results indicated that the data were adequately fitted into three second-order polynomial models. The independent variables, the linearity of extraction time and temperature, the quadratics of extraction temperature and ratio of liquid to solid had a significant effect on the yield of polysaccharides. The optimal extraction parameters were extraction time of 140 min, temperature of 100 °C and the ratio of liquid to solid of 3, according to the response surface analysis. Pharmacology experiment showed that dioscoreae polysaccharides decreased serum ALP, IL-6 and BGP levels, and enhanced BMD, BMC, bone Hyp, Ca2+ and P3+ levels.