Extraction optimization of polysaccharides of Schisandrae Fructus and evaluation of their analgesic activity

Polysaccharide from the Schisandrae Fructus (SFP) has been considered as the major effective component with many activities and high content. To obtain SFP more efficiently and clear up its analgesic activity, the three-factor, three-level orthogonal extracting test was designed to optimize the extraction condition based on the results of single-factor experiments. The optimal parameters were determined as extraction time of 1.5 h, extraction number of 4 times and ratio of water to raw material of 8-fold, respectively. The major monosaccharide component was identified by HPLC, and its characteristic was checked by UV and IR. The in vivo analgesic experiments revealed SFP significantly prolonged the latent period of writhing and reduced the writhing frequency produced by intraperitoneal injection of acetic acid, and prolonged the interval of licking of the hind paws on a hot-plate by mice. SFP could be a potential analgesic agent in the future according to our results.