PCR Test Evaluating The Effects Of Allicin On Toxoplamosis In Experimentally Infected Mice

This study aimed to evaluate the effectivity of allicin alone or combined on toxoplasmosis in order to select drugs of high efficacy and no side effect. Firstly, a specific, rapid, and sensitive PCR technique was established and used to diagnose Toxoplasma gondii infection. RH strain of T. gondii was pured from intraperitoneally infected mice. DNA of T. gondii was extracted and used for PCR test. Key steps of PCR were opitimized and the target was Bl gene. In order to determine specificity of Bl-PCR, amplificaton using the same primer pairs was performed with DNA from Cryptosporidium,Pneumocysis carinii and Plasmodium berghei. Bl-PCR was also used to detect the DNA of blood and liver tissue of experimentally infected mice with T. gondiiThe optimized annealing temperature of Bl-PCR was 55 癈 and the concentration of Mg2"1" was 1.5mmol/L or 2.0mmol/L. DNA in a single organism can be amplified and detected with PCR test. No amplification was seen with DNA from Cryptosporidium.Pneumocysis carinii and Plasmodium berghei. DNA of T. gondii from whole blood and liver tissues of infected mice could be detected as early as day 2 post infection. The total positive rate reached to the highest value 100%( 11/11) when detecting blood samples and 81.8%(9/11) detecting liver samples.Secondly, different drugs on toxoplasmosis were evaluated by the established PCR test. 147 mice were infected with 2 X 104 tachyzoites and randomized into 5 groups and each group was divided into two sub-groups except untreated group. Onesub-group was used to get samples for PCR test and the other to observe the duration of survival. The therapeutic strategies were the following: group A, SMZco administered orally 7 days and allicin administered orally 21 days; group B, SMZco administered orally 14 days and allicin 21 days; group C, allicin alone administered orally 21 days; group D, SMZco alone administered orally 7days; group E, untreated controls. The drugs were given at 4 hours after infection and the dosage is SMZco 400mg/kg/d and allicin 35mg/kg/d. PCR test was used to detect the parasites in the samples of liver and blood from infected mice at 5,10,15,20,25,30,40,50days after infection.Parasites was eliminated in the blood because no signal was seen in all the blood samples except group C at day 5 post infection. From day 10 post infection till the end of the observation, no amplification of DNA was seen in all the samples. As for liver samples examined with PCR test, signals were clear at day 5 post infection. From day 10 post infection till the day 50 post infection, parasites were still detected, but the PCR products much more decreased than those of day 5 post infection. These results reveal the treatment strategies except for group C were effective but can't eliminate the parasites completely. Log-rank test and wilcoxon(genan) statistics were used to compare the difference of the survival rate and survival duration of different groups. The results were the following: the survival rate and survival duration of the mice in sub-group A was significantly higher than those in sub-group D; sub-group D was marked higher than sub-group E; sub-group C was not significantly increased compared with sub-group E in the survial rate and suivival duration; sub-group B was no significant increase compared sub-group A.These results reveal SMZco is effective on treatment acute toxoplasmosis . Allicin is not effective in treatment acute toxoplasmosis, but when combining with SMZco are much more effective and act synergistically.