Histopathological analysis reveals mild to moderate changes in BALB/c mice after short-term administration of a microemulsion loaded with epoxy-α-lapachone.

The development of innovative treatments for American Cutaneous Leishmaniasis is crucial due to severe side effects of current treatment and the emergence of non-responder parasites. To address such a challenge the incorporation of epoxy-α-lapachone (ELAP) into a microemulsion (ME), named ELAP-ME, represents a promising therapeutic approach. In previous studies, ELAP-ME demonstrated efficacy in controlling infection in the BALB/c-Leishmania (Leishmania) amazonensis model, advancing in the technology readiness level with a drug prototype. To further validate its potential as a drug prototype, the histopathological effects of ELAP-ME were investigated in healthy BALB/c mice as a preclinical approach stage. Mice were administered with a fixed dose of ELAP-ME microemulsion (∼7 μg/kg) and evaluated at different short-term after administration (4, 12, and 24 h). Histopathological analysis of the liver, kidney, lung, heart, and brain revealed only mild alterations. These findings confirm the low toxicity profile of ELAP-ME, highlighting its safety and supporting its continued advancement as a pharmacological alternative for the treatment of leishmaniasis.