Study On Detection Of GibberellicA₃ By HPLC Method And On Oxidation Damage In Mice

This research not only set up a sample pretreatment method, but also established a quick, accurate detection method of GA₃ ,basing on optimization of the existing HPLC conditions and sample disposal methods. Besides, we detected several merchant fruit and vegetable samples, in order to provide references for our government and ensure that our food was safety. At last, we researched toxicological mechanism of GA₃ by doing some experiments of GA₃'s oxidative damages on different white mice organs. The following are main results.1. Optimized HPLC ConditionsC₁₈ reversed phase column with linkage stationary phase, UV detector, detection wavelength of 206nm, mobile phase of methanol- 7.5mM formic acid aqueous solution(4:6,V/V ), column temperature of 40℃, sample volume of 10μl. By debugging the composition and flow rate of mobile phase repeatedly, we found that all the peaks had stable retention time,and better shapes than the other methods.2. Pretreatment Method of SampleGA₃ was extracted by ultrasonic with acetone-water extractant (5:4,V/V), and then purified by discoloration of petroleum ether, extraction of ethyl acetate, and treatment of SPE. It was important that this methord had better removing impurity effect and shorter time higher samples purity than the other methods3. Residual Situation of GA₃ in Some Merchant Fruits and VegetablesSome early-maturing products had higher residual values of GA₃, especially for soybean sprouts and early-maturing grapes. Soybean sprouts and early-maturing grapes had 3.17mg/kg and 2.3mg/kg of GA₃ respectively,being far beyond the standards in Europe and America.4. Effects of GA₃ on Body Weight and Oxidative Damage to the Organs in Mice(1)Effects on Organ Weight / Body WeightAfter intake treatment, there was no significant difference on body weight among all treatment groups and control group; The liver coefficient of the group at 788 mg/kg bw GA₃ intake level was significantly lower than the solvent intake group(P<0.05); showing that to some extend the dose of GA₃ influenced the liver of mice;compared with the control group,there was no statistically significance in the body weight ,heart and kidney coefficient of treatment group;The coefficient of spleen was higher along with the increase of dose,but had no statistically significance. (2)Effects on Liver and SpleenThe index of oxidatie stress of spleen and liver changes significantly at 394 and 788 mg/kgbw GA₃ intake level. The SOD and GSH-Px activity in the spleen (P<0.05 , P<0.01), which decreased 21.01%, 29.02% and 23.36%, 35.03%, respectively; and the SOD and GSH-Px activity in the liver of the above GA₃ intake groups were also significantly lower than those in the control group (P<0.05 , P<0.01), which decreased 9.01%,13.05% and 12.81%,16.17%, respectively. The contents of MDA were remarkably higher than those in the control group at the same intake groups, increased 19.06% and 23.61% in the spleen, along with 22.33% and 26.39% in the liver. There was significantly different by statistical processing(P<0.05 , P<0.01).(3)Effects on KidneyThe SOD and GSH-Px activity in the kidney were higher at 394 and 788 mg/kgbw GA₃ intake level. which increased 22.34% and 40.20% , while MDA contents decreased 35.93% and 30.05%, comparing to the control group. The results were statistically significant.(4)Effects on HeartThere was no significant difference on the the indicators of intake group in the heart between all treatment groups and control group (P>0.05). Conclusions:The established method had a good linearity, and its correlation coefficient was more than 0.999, 93.10%of the average recovery and 0.012μg/g of the detecting limit.Some early-maturing products and sprouts had high residual GA₃ concentration. It was found that GA₃ had different oxidative stress in different mice tissues and organs, and caused a significant oxidative damage in the spleen and liver. What`s more GA₃ had no significant oxidative damage in the heart, but maybe had a protective effect on the kidney.