The growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkia affected by dietary Rhodiola rosea polysaccharide.

This study aims to investigate the effects of Rhodiola rosea polysaccharide (RRP) on the growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkia. RRP was prepared by hot water extraction and partly characterised by high-performance liquid chromatography and sugar composition analyses. Three diets supplemented with three different levels of RRP (0.2, 0.6 and 1 g kg diet-1) were formulated and tested for growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkii, while a diet without any RRP supplementation served as control. After 8 weeks of feeding, body weight gain, feed efficiency, survival rate, phenoloxidase activity, superoxide dismutase activity, glutathione peroxidase level, total haemocyte count and number of hyaline cells, semigranular cells and granular cells and resistance to Aeromonas hydrophila were higher than those of the control. Moreover, based on the efficiency of RRP on the growth performance and nonspecific immunity of crayfish, the optimum dose of RRP was found to be 0.6 g kg diet-1. Hence, intake of diets containing RRP could enhance the growth performance, immune responses and improve resistance of crayfish to infection by A. hydrophila.

Effect of Astragalus membranaceus polysaccharide on the serum cytokine levels and spermatogenesis of mice.

In this work, a water-soluble Astragalus membranaceus polysaccharide (AMP) was prepared by hot water extraction, and the effects of AMP on the serum cytokine levels and spermatogenesis of Kunming mice were investigated. Sixty Kunming mice were randomly divided into five groups: a normal control group, a model control group (treated with cyclophosphamide) and three treatment groups (treated with cyclophosphamide and 25, 50 and 75 mg/kg AMP). The effects of AMP on the serum cytokine levels and spermatogenesis of mice were evaluated. Intragastric treatment with different levels of AMP significantly increased serum interleukin-11, tumour necrosis factor-α and interferon-γ levels; protein expression and superoxide dismutase activity in testis; and sperm density, sperm movement and the rate of normal sperm morphology. In addition, AMP decreased the nitrate nitrogen level in the testes of Kunming mice compared with the model control group. The results indicated that AMP can ameliorate the immunity and spermatogenesis of mice with reproduction system impaired by cyclophosphamide.