Studies On The Preparation, Antioxidant Activities Of Polysaccharides From The Shoots Of Phyllostachys Edulis And Its Immune Effect On Eriocheir Sinensis

The water-soluble polysaccharide was extracted from the shoots of Phyllostachys edulis with ultrasonic wave. The response surface methodology was applied to determine the optimum technological conditions. The results indicated that the optimum extraction conditions were as follows:the water-material ratio was30:1, extraction temperature was50℃, extraction time was35min, ethanol concentration was90%. Under the conditions mentioned above, the predicted yield of bamboo shoots polysaccharide was2.944%, and the experimental yield was2.938%. The physical and chemical properties, ultraviolet spectroscopy and infrared spectroscopy showed that the extract was polysaccharide and presumably was a kind of α-pyran-glucan. The total sugar content of the polysaccharide was65.3%measured by phenol-sulfuric acid method.The scavenging effects on hydroxyl radicals, superoxide anion radicals and hydrogen peroxide and the inhibitory effect on lipid peroxidation of bamboo shoots polysaccharide on concentration0.1～10mg/mL were studied with ascorbic acid as a positive control. The results showed that bamboo shoots polysaccharide had significant scavenging effects on superoxide anion radicals and hydrogen peroxide which were higher than the same concentration of ascorbic acid. Otherwise, the scavenging effect on hydroxyl radicals and the inhibitory effect on lipid peroxidation were lower than that of the ascorbic acid. This study indicated that bamboo shoots polysaccharide had strong in vitro antioxidant activity.Crab were coelom injected at1,5,10and20mg/kg weight with bamboo shoots polysaccharide, with injected0.1mL sterile saline group as control. A series of immunology parameters were examined at1,4,7, and10days after administration of polysaccharide. Crab were challenged at1.2×107colony forming units (cfu)/kg weight with a virulent strain of Aeromonas hydrophila (CL99920) of E. sinensis at the second sampling time (4d), and mortalities were recorded over a7-day period. The results demonstrated that the total haemocyte count (THC), the haemocyte phagocytic activity, the phenoloxidase (PO), peroxidase (POD), lysozyme (LSZ) in serum, the nitrie oxide synthase (NOS) in hepatopancreas and the superoxide dismutase (SOD), acid phosphatase (ACP), alkaline phosphatase (ALP), total antioxidant capacity (T-AOC) in serum and hepatopancreas of E. sinensis were significant higher than those of the saline control group (P<0.05). However, no significant differences were observed in the respiratory burst (release of superoxide anion) in haemocyte of E. sinensis (P>0.05). Furthermore, the crabs administered with bamboo shoots polysaccharide were more resistant under the conditions of this experiment. On the whole, the crabs injected at10mg/kg weight with bamboo shoots polysaccharide had a stronger non-specific immune response and resistance to A. hydrophila.