Zhou Qunlan

Effects of anthraquinones extract from Rheum officinale Baill on the hepatopancreas antioxidative capacity and HSP70 gene expresssion under high temperature of Macrobrachium rosenbergii

Macrobrachium rosenbergii,also known as the giant river prawn,the giant freshwater prawn or the Malaysian prawn,is the most important cultivated species of freshwater shrimp in the world.This species(as well as other Macrobrachium) is commercially important for its value as a food source.In China,the production of M.rosenbergii has been increasing in recent year.However,cultured M.rosenbergii in China as well as in other parts of the world have suffered from various stress factors such as ambient temperature,stocking density,physicochemical parameters,transport,and storage.Stress means the sum of nonspecific responses of organisms to various acute stimuli inside and outside.It is a physiological response of any organisms in the long evolution process to extend its adaptation,but excess response,which inhibits immunity,improves the free radical contents,destroys the homeostasis between producing and cleaning-up of free radical,and attacks the double bond of polyunsaturated fatty acid in plasma membrane,the last leading to increase the lipid peroxidation contents and lipid peroxidation injury.So these are many disadvantageous impacts on organisms and it causes fish to infect diseases even to die.Therefore,how to alleviate stress response is the research focus in this field.The present research falls on substances,which can strengthen immunity of organisms and alleviate stress,e.g.vitamin C,vitamin E,lipid acid,metal ion,fructose,astacin.Chinese herbal medicines have many merits:natural,highly effective,low toxicity,low side effects,and rich in resources.Chinese herbal medicines have many effective components,such as organic acids,alkaloid,saccharide,volatile oil,wax,glycoside,tannic acid substance and some unknown factors that can elevate fish immunity and enhance the growth.However,few reports have been found in studying the effects of Chinese herbal medicines on the hepatopancreas antioxidative capacity and the level of HSP70 mRNA under high temperature of M.rosenbergii.In view of this,M.rosenbergii were divided into 5 groups randomly.The control were fed with basal diet,the others the treated groups were fed with basal diet supplemented with 0.05%,0.10%,0.20%,0.40% anthraquinone extracts for 10 weeks,respectively.After that,shrimp were stressed by high temperature at 35 ℃ for 48 h continuously.The changes of total antioxidative capacity(T-AOC),catalase(CAT),superoxide dismutase(SOD),nitrogen oxide(NO),malondialdehyde(MDA) and the mRNA level of heat shock protein 70(HSP70) in hepatopancreas before and after the stress were investigated.The results showed that compared with the control,0.05% dose of anthraquinone extract could elevate CAT,SOD activities and reduce MDA concentration,0.20% dose group improved T-AOC and NO content and reduced MDA concentration,and 0.10%,0.20% doses groups improved also the relative content of HSP70 mRNA before the stress.After 35 ℃ high temperature stress,T-AOC,CAT activities,SOD activities,and NO concentrations in hepatopancreas were decreasing in all groups of which the control relatively lower and 0.10%-0.20% doses groups were relatively higher,while MDA contents were increasing trend in all groups of which the control was relatively higher and 0.10%-0.20% doses groups were relatively lower.The relative content of HSP70 in hepatopancreas 6 h after the stress in 0.10% and 0.20% doses groups were higher than those of the control.It is concluded that ingestion of 0.10%-0.20% doses of anthraquinones extracts could improve the antioxidative capacity,elevate the relative content of HSP70 mRNA and help prevent negative effects of high temperature stress to a certain degree.