IN VITRO AND IN VIVO STUDY OF ANTIFUNGAL FORMULATION AMPHOTERICIN B-7-DEHYDROCHOLESTEROL COMPLEX: TOXICITY AND ACTION ON EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS

Abstract

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis that can progress to severe and lethal disseminated forms when not diagnosed and treated early. Amphotericin B deoxycholate (AMB-D) is the main option for the intravenous treatment of severe disease cases; however, its use is limited due to high nephrotoxicity. This study aimed to evaluate the in vitro and in vivo toxicity of the AMB-7DC complex—a water-soluble and thermostable formulation resulting from the binding of AMB-D to the 7-dehydrocholesterol radical. This modification reduces its reactivity with cholesterol, which can minimize side effects. In addition, the in vivo fungicidal action against P. brasiliensis was evaluated. In vitro toxicity  was analyzed by hemolysis test in sheep erythrocytes, while in vivo toxicity was determined by the maximum tolerated dose in BALBc mice. The antifungal efficacy was evaluated by quantifying the fungal load (CFU) in BALB/c mice infected with P. brasiliensis (1.2 × 10⁶ cells/mL) and treated or not with antifungals. The study was approved by the Ethics Committee on Animal Experimentation of the State University of Londrina (CEEA nº 38/05, process nº 23944/05). The results indicated that AMB-7DC showed lower toxicity compared to AMB-D, both in vitro and in vivo assays. Regarding the fungal load, a reduction was observed in the treated groups compared to the infected control group (p < 0.05), but without a significant difference between the AMB-D and AMB-7DC groups (p > 0.05). Based on these preliminary findings, it is concluded that AMB-7DC maintains its antifungal activity against P. brasiliensis, presenting lower toxicity compared to AMB-D. Thus, the AMB-7DC complex demonstrates potential for the treatment of PCM, and additional studies are needed for further evaluation.