Evaluation Of In Vitro Inhibitory Sexually Transmitted Disease Pathogens Activity For Chitosan-iodine

Sexually transmitted diseases (STD), of which main mode of transmission is sexual contact, have received widely concern in recent years. Internationally, more than 30 kinds of infectious diseases caused by sexual behavior or similar sexual behavior belonged to STD. STD with the most extensive incidence not only do the most serious harm to us human, but also are a global issue to reproductive health and epidemic prevention. So far, though we have gained some encouraging achievements on the treatment of various STD, the most serious STD has received no effective way of treatment due to the high complexity and variability of virus and other exually transmitted disease pathogens [1]. The word microbicides refers to a new type of product being developed that people could use vaginally or rectally to protect themselves from HIV and possibly other sexually transmitted infections.Therefore, developing highly efficient, inexpensive and safe microbicides has become the most important way to prevent STD. The United Nations AIDS programme (UNAIDS) and World Health Organization (WHO) has regarded the research of microbicides as a global priority in development strategies. Over the past 10 years, this field has made significant achievements, but so far, no safe and effective microbicides were listed. To be specific, more than 60 kinds of microbicides have been entering into pre-clinical and clinical trials, and up to October 2009, 9 of them have developed into clinical trials [2, 3].In order to find novel and effective pharmaceutics to prevent SID, this paper studied the chitosan-iodine against Candida albicans and herpes simplex virus (HSV) through MTT assay and time course experiments and pre-function test. To study the stability of chitosan-iodine, of which the effective iodine concentration was 4.897 g/L, it was put inside the thermostat at a constant temperature of 54℃for 14 days. Then, the detected concentration turned to 4.536 g/L, and only changed 7.3%, showing the better stability of the chitosan-iodinen. As for the inhibition by chitosan-iodine, the MIC50 for Candida albicans was 0.25 mg/mL. For the HSV, the EC50 was 0.025 mg/mL, and the therapeutic index TI50 was 24. In addition, the results also showed that the longer the pre-function test of chitosan-iodine with human herpes simple virus (HSV), the smaller HSV title was. If the chitosan-iodine was added within 2 hours when virus infected the cells, it has a strong inhibitory effect against HSV. Comparative drug ACV, which acts on viral DNA replication phase, is synthetically nucleoside antiviral drugs. In the time course experiments, ACV started to act when HSV have infected cells for 6 hours, while in the pre-function test, there has no large impact on the virus titer after adding ACV within 20 minutes. It would be speculated that the action sites of the chitosan-iodine is in the virus adsorption stage, and it could interact with the virus directly so as to achieve the effect of inhibition on virus activity.In conclusion, chitosan-iodine has a strong inhibitory effect against Candida albicans and HSV, and it provides a theory basis to further study it as microbicides.