In Vitro Drug Sensitivity of Trypanosoma evansi Bangkalan Isolates Folia Medica Indonesiana Vol. 41 No. 1 January – March 2005 43 IN VITRO DRUG SENSITIVITY OF Trypanosoma evansi BANGKALAN ISOLATES Mochamad Lazuardi ABSTRACT Only a limited number of drugs is available for Trypanosoma infection treatment. In Indonesia there are two chemoterapheutics (isometamidium and diminazene) used for treatment. The isometamidium does not act as a trypanocide of Indonesia isolates. However, the clinical action of diminazene to Trypanosoma has not been reported yet. The objective of this research was to obtain trypanocide concentration of Trypanosoma evansi Indonesia isolates by in vitro test. Drug sensitivities of Trypanosoma evansi Bangkalan isolates modified using Minimum Eagle Medium and HEPES medium were measured for diminazene aceturate and suramin using in vitro incorporation test. In control group, trypanosome inoculate was added as a placebo substance in microtiter plate containing trypanosomes. Bloodstream forms were isolated from Wistar strain Rattus norvegicus, incubated at room temperature in serial drug dilutions in a microtiter plate by adding 5 % of CO2. After 24 hours, the trypanosomes were counted by inverted microscope to determine trypanocide action. The two subjects research were different trypanocide action (p<0.05). The minimum concentration with trypanocide action of diminazene aceturate was found to be 8.480 µg.ml -1 .The minimum concentration with trypanocide action of suramin was 6.600 µg.ml -1 . Keywords: diminazene aceturate, suramin, Trypanosoma INTRODUCTION African sleeping sickness and chagas diseases, which may be fatal if not treated, is caused by Trypanosome species. In veterinary, the trypanosomes case remains a problem and it can result in major scale economic decrease in farm industries. Only a limited number of drugs are available for the treatment of Trypanosoma species infection (Brun et al., 1989). The most commonly used ones are suramin for early stage and Mel B for advanced stages of the diseases. In veterinary the isometamidium chloride (Phenantridium) is also used to treat infection of T. evansi, but it needs a large dose to kill the parasites (Roostantia et al., 2003). For CNS involvement in advanced stage, Mel B, as a part of DFMO new drugs, is predicted to be suitable in treating chronic patients (Van Niuwenhove, 1992). However in recent years, cases of drug failure with Mel B have been reported. Over 10 % of treated trypanosomes infection suffered relapses. Mel B resistant isolates of T.B. gambiense have thus far not been demonstrated in the field. Diminazene aceturate (Berenil ® ) is a well-known kinetoplasticide that has been used extensively throughout the world. In recent years, most of the clinical trials published originated in Africa, where such _________________ Department of Veterinary Pharmacy Airlangga University School of Veterinary Medicine Surabaya infections are still common like a T. congolense (Gummow et al., 1995; Wahyudi et al., 2005). The clinical application of diminazene against T. evansi Indonesia isolated was not reported yet. In other side, the diminazene has a good prospect as a drug of choice against to T. evansi Indonesia isolates. For the first time, this study investigated trypanocide action of diminazene by in vitro test but not all techniques can be used in Indonesian conditions, although Croft et al., (1997) reported that various in vitro methods have been described for assessing the sensitivity of trypanosome populations to trypanocidal drugs. In this report we described the antitrypanosomal effects of diminazene aceturate and suramin by simple in vitro technique for specific species of Indonesian veterinary trypanosomes as well as their trypanocide action for the leishmaniasis, chagas disease and african trypanosomes. The objectives of this study were: 1. To obtain trypanocide phenomenon of diminazene and suramin against local trypanosomes isolates (T. evansi Bangkalan isolates) 2. To obtain of trypanocide concentration of diminazene and suramin by in vitro test against local trypanosomes isolates (T. evansi Bangkalan isolates).