Study On Optimization Of Saponins Extraction And Its Inhibition Of Acute Hypobaric Hypoxia Of Brassica Rapa L.

Brassica rapa L.had been planted for more than 1000 years,which was a food,medicine and feeding plant grown in the harsh environment of cold and low oxygen in the Tibetan plateau.Brassica rapa L.had a sweet taste,mild property and possessed the effects of “heat-clearing and detoxification”,“tonic and anti-hypoxia” according to the famous Tibetan medicine book “Four Medical Codes”.According to the related literatures,Brassica rapa L.and its extracts had good effect of anti-hypoxia.However,there are few reports on the extraction and process optimization of Brassica rapa L.and no reports on its inhibition of acute hypobaric hypoxia.Therefore,in this study,the response surface methodology(RSM)was used to optimize the ultrasound-assisted extraction process of Brassica rapa L.and the toxicity of Brassica rapa L.on Jurkat cells was preliminarily explored.Then,the acute hypobaric hypoxia mice model was established to study on the inhibition of acute hypobaric hypoxia of Brassica rapa L.and which lays the foundation for further research on the prevention and treatment of high altitude diseases by Brassica rapa L..Objective:1.Optimization of extraction process of Brassica rapa L.saponins by response surface methodology.2.Preliminary study on cytotoxicity of Brassica rapa L.saponins.3.To study the inhibition of acute hypobaric hypoxia of Brassica rapa L.saponins.Method:1.Respectively to investigate the effects fo single factor extraction time(min),extracting temperature(℃)and liquid-material ratio(mL/g)on the extraction yield of Brassica rapa L.saponins and based on the single factor extraction experiment,the response surface methodology was used to design the experiment with three factors and three levels,and the content of Brassica rapa L.saponins was determined by vanillin-perchloric acid colorimetry.2.On the basis of preliminary experiments,the concentrstions of Brassica rapa L.saponins were 200 μg/ml、160 μg/ml、120 μg/ml、80 μg/ml、40 μg/ml in the Jurkat cytotoxicity assay,and the cell viability was measured after 12 h,24h,48 h respectively.3.To establish acute hypobaric hypoxia mice model(4000m)by hypobaric hypoxia chamber and observe the pathological changes of heart and brain tissues in mice,and detect the related biochemical indexes(SOD,GSH-Px,T-AOC,ATPase,LD and LDH)in the heart and brain tissues,and to study the inhibition of acute hypobaric hypoxia of Brassica rapa L.saponins.Results:1.According to the results of single factor experiment,the three levels of extraction temperature,extraction time and liquid-material ratio(mL/g)were determined as follows: 50 °C,60 °C,70 °C;25 min,35 min,45 min;1:15,1:20,1:25.The optimal extraction conditions of Brassica rapa L.saponins were determined by response surface methodology(RSM): extraction temperature 61.40℃,liquid-material ratio 21.82:1,extracting time 35.96 min,saponins extraction yield was 0.3691%,and The verification experiment results show that the predicted value of the model was less than the actual value;2.Within the range of concentration,the cell survival rate decreased with the increase of saponins concentration,and the cell survival rate also decreased with the extension of culture time,and the cytotoxic IC50 of Brassica rapa L.saponins was 165.8 μg/mL.3.Compared with the normobaric normoxia group,the hypobaric hypoxia control group showed pathological injury in the heart and brain tissues,and the activities of SOD,GSH-Px,T-AOC,ATPase,LD and ATPase in the heart and brain tissues were significantly decreased,while the contents of LD and MDA and the activities of LDH were significantly increased.Compared with the hypobaric hypoxia control group,the pathological damage of heart and brain tissues was reduced in the saponin group,and the activities of GSH-Px,T-AOC,SOD and ATPase were increased variously,the contents of LD and MDA were decreased variously,the activity of LDH was decreased variously in the heart and brain tissues of saponin group.Conclusion:1.The extraction method of Brassica rapa L.saponins was simple and rapid,the optimal extraction conditions were as follows: extraction temperature 61.40℃,liquid-material ratio 21.82:1,extracting time 35.96 min,saponins extraction yield was 0.3691%.2.within the concentration range,the cytotoxic effect of Brassica rapa L.saponins on Jurkat cells was dose-dependent and time-dependent,and the cytotoxic IC50 of Brassica rapa L.saponins was 165.8 μg/ml.3.The Brassica rapa L.saponins had the inhibition of acute hypobaric hypoxia.