Studies On Toxicity And Bacteria Degradation Of Oxytropis Glacialis Toxin

Oxytropis and Astragalus species known as Locoweeds are responsible for Locoism and other problems. Locoweeds are mainly distributed on the vast rangeland, exceeding 11 million hectares, in northwest, north and southwest China. Resent years, Locoweeds have been deeply researched all over the world .However, there is no effective method to control Locoism. Locoism has become an important disease on the vast rangeland. O.glacialis is one kind of Locoweeds that only distributed in the area of Ali, Tibet. In this paper, researching the toxicity of O.glacialis'toxin, isolation of swainsonine(SW) from O.glacialis and degradation toxin with bacteria. The results are as follows. 1. TMPD was feed to four goats constantly at 0.38g/(kg﹒d). 21 days later, some goats appeared the poisoning symptoms. 42 days later, some goats were stumbled, felled down easily, could not stand up. The blood routine items results showed that the number of RBC and LC declined sharply (P <0.05 or P <0.01), PCV, Hb decreased slightly, Lymphocytes occurred vacuolation in the blood. Biochemistry items showed that the BUN, LDH and ALT raised obviously(P <0.05 or P <0.01),while serumα-mannosides activity reduced obviously (P <0.01 or P<0.05). These results proved that heart, livers, kidney, brain and other viscera were damaged by toxin of O.glacialis. Histopathological changes showed that heart, liver and other viscera were vacuolation. The TMPD was a main toxicant in the O.glacialis . 2. Seventeen rabbits were divided into control group (n=6) and experimental group (n=11). In the experimental group, rabbits were fed with O.glacialis of 10g/(kg ﹒day).Blood biochemical indexes were measured respectively during feeding. The results indicated that the activities of serum AKP,GOT and BUN value of poisoned rabbits were significantly higher (P <0.05 or P <0.01), while serum α-mannosides activity significantly lower (P <0.01).Lymphocytes occurred vacuolation in the blood from 4th day. Histopathological examination showed that heart, liver, spleen, lungs and kidney were all vacuolized. These results proved that brain, livers, kidney, heart and other viscera were damaged by toxin of O.glacialis. Rabbit have better ability to bear the toxin of O.glacialis than other susceptible animals and may not exist degrade bacteria in their gastrointestine. The toxin may be contain indolizidine alkaloids. Animal O.glacialis poisoning was caused by TMPD and other toxin. 3. It was the first times to separated and purified the SW from O.Glacialis. The total alkaloid was extracted by hot methanol from O.glacialis powder with an ratio of 5.5%. The extraction was further extracted respectively with chloroform,ethyl acetate and butanol. The most alkaloids were maximum polarity in the butanol phase. With TLC checking on alkaloids,there were 10 alkaloids in chloroform phase, 7 alkaloids in ethyl acetate and 5 alkaloids in butanol phase. The alkaloids in chloroform phase analyzed by GC-MS. There were 17 alkaloids among those 7 kinds were defined the structure and other are not. Applied the crude alkaloid extracted with butanol to a silica gel column, eluted with different proportion ethyl acetate and methanol, monitored by TLC, incorporated the same fraction. Sublimated the Ehrlich's colorable fraction and obtained white needles crystal in the end.The chemical structures were identified as SW by means of MP and IR, MS, 1HNMR, 13CNMR. 4. It was the first times to establish a method of determine the TMPD by ultraviolet-spectrophoto-metric method. The method is not need high condition, simple and convenient, can fast quantitative analysis the TMPD. 5. Separated the bacteria from the soil in which locoweed grows, and selected the bacteria by culture medium using TMPD as sole carbon source.12 colonies of bacteria that could degrade TMPD, then resorted to repeat sifting and separation, at last chose four colonies of bacteria as the experimental targets.The Grame staining and watching through light microscope for the four colonies chosen, Three of them are G-bacillus and the other is G+ coccus. 6. The degradation ratio of 12 strains bacteria to TMPD was measured. After measurement, there were 4 individuals bacterium had relatively high degradation rate to TMPD. The No 2# had highest degradation ratio that was 82.54% after cultured 30 days later, and the other 3 strains bacteria's were more then 60%. Tested the degradation ratio under different culturing conditions. The results showed that the initial stage concentration as 200 mg/L and the fostering temperature as 30℃was helpful to microbe developed degradation. The liquid culture media was extracted by butanol, and analyzed by GC-MS. There were 8 kindsof alkaloids and 5 degradations most were esters. The mechanism of degradation was complex and further studies are needed. 7. Used 4 colonies of bacteria as the experimental targets to degrade SW. Continuously culturing for 9 days, centrifugal 10 minutes at 7500 r/min. extracted by butanol. The content of SW in the extracted matter was detected. The results proved that 3 strains of No 2#,6# and 11# bacteria were not ability to degrade SW. No 9# strain bacterium could degrade SW, the degradation ratio was 14.2%. The results pave a way for eliminating the toxin contained in locoweed.