Preliminary Study On Anti - Tuberculosis Effect Of Vitamin C

Objective: To determine the MIC of AA against M.tb H37 Rv and to establish a guinea pig aerosol infection model, then apply it to evaluate the antitubercular activities of AA in vivo.Method:The MIC of AA against M.tb H37 Rv was determined by 7H11 solid medium. The guinea pigs were infected with M.tb H37 Rv using inhalation exposure system.The guinea pigs were sacrificed at 2 weeks, 4 weeks and 7 weeks respectively after infection. The severity of infection was assessed by lung weight indice, spleen weight indice, the numbers of CFU in the lungs and spleens and the pathological changes in lungs. Apply this model, at 10 days after infection, animals were randomized into untreated groups, INH groups and AA groups, and sacrificed after 3 weeks and 6 weeks of the treatment. Then the organ weight indices, the numbers of CFU in lungs and spleens and the pathological changes in lungs were evaluated to assess the antitubercular activities of AA in vivo.Results: The MIC of AA against M.tb H37 Rv was 200 μg/m L. The number of M.tb H37 Rv of the aerosol infection is 6×104 CFU/m L. At 2 weeks after the infection, the number of CFU in lungs was 4.57±0.18 log10 and the histological evaluation is inflammation. After 4 weeks after the infection, the number of CFU in lungs was 5.83±0.02 log10 and the histological evaluation revealed the nodular and granulomas. After 7 weeks after the infection, the number of CFU in lungs was 5.83±0.17 log10 and the histological evaluation revealed the multiple necrotic granulomas. The differences of lung weight indice, spleen weight indice, the numbers of CFU in the lungs and spleens are non-significant and the pathological changes are similar between the AA group and untreated group. While the differences of spleen weight indice, the numbers of CFU in the lungs and spleens between in INH group and untreated group were significant(P<0.05), and the pathological changes in INH group were better.Conclusion: There is an antitubercular activity of AA in vitro, the MIC is 200 μg/m L. But we didn’t find the antitubercular activity in guinea pig model in this study.Objective:As a result of the need of actual clinical treatment, high dosage(> 2 g/d) of AA has been applied in different disease in the clinical treatment, e specially it is used widely in the field of complementary and alternative medic al(CAM), diseases such as cancer, infectious disease and autoimmune disease treatment. But it is still a lack of evidence-based medicine the safety of the cl inical application of high dosage of AA which limits the application. For provi ding evidence-based reference for the clinical treatment, we will evaluate the s afety of high dosage of vitamin C treatment system in this study.Method: The databases of Pub Med, EMbase, Cochrone, CNKI, Wan Fang datab ase and VIP database were retrieved with computers for collecting clinical trial s about the use of high dosage of vitamin C up to Aug. 2014. A Meta-analysi s was conducted by using R software.Results: There were 23 clinical trials including 2069 patients with 540 adverse events. There were no acute hemolysis, oxalate kidney disease, kidney failure and other serious adverse events in our study, only 1 case of patients with uri nary tract stones, whose occurrence was related to urinary calculi history.The s afety results of Meta-analysis showed that the RR and 95%CI between the vita min C experiment group and control group is [1.42,95%CI(0.92, 2.20)], an d showed a non-significant difference(P=0.382)for controlled studies. The inci dence of abdominal pain, thirsty, headache, nausea, diarrhea were [9%,95%CI(0.05,0.14)],[30%,95%CI(0.14,0.54)],[12%,95%CI(0.06,0.25)],[25%(0.13; 0.44)],[14%,95%CI(0.07,0.26)] for all enrolled studies, separately.Conclusion: However, after strictly screening G6 PD, according to the present meta-anyalysis results, there is no evidence of evidence-based medicine show t hat the use of high dosage of vitamin C can lead to severe adverse effects in the short term,and pay attention to the digestive system symptoms. Due to the lack of large scale RCT data and the short follow-up time, the comprehensiveevaluation is limited. More with multiple-center and large-sample randomized controlled trials are required.