Anti-piroplasmic activity of novobiocin as heat shock protein 90 inhibitor against in vitro cultured Theileria equi and Babesia caballi parasites

Theileria equi and Babesia caballi are the causative agents of equine piroplasmosis (EP). Currently, imidocarb dipropionate (ID) is only available drug for treating clinical form EP. Serious side effects incomplete clearance infection a major drawback ID. Heat-shock proteins (Hsp) play vital role in life cycle these haemoprotozoans by preventing alteration protein conformation. These Hsp activated during transmission EP sporozoites from tick vector (poikilotherm) to natural host (homeotherm) facilitate parasite survival. In present study, we targeted heat shock 90 (Hsp-90) pathway T. B. using its inhibitor - novobiocin. Dose-dependent efficacy novobiocin on growth was observed vitro culture. Additionally, examined dose-dependent cell cytotoxicity peripheral mononuclear cells (PBMCs) haemolytic activity red blood (RBC). vivo organ toxicity also assessed mouse model. The IC50 (50 % inhibitory concentration) value against 165 μM 84.85 μM, respectively. Novobiocin significantly arrested parasites at 100 200 concentration, treated had distorted nuclear material showed no further viability. Based PBMCs RBC, found be safe even 1000 concentration CC50 values were 11.63 mM 261.97 mM. Very high specific selective index (SSI) (70.47 1587) Organ-specific biochemical markers histopathological examination indicated adverse effect dose rate 50 mg kg body weight results demonstrate safety lines with very SSI. Hence, it can inferred that Theileria/Babesia Hsp-90 family potential targets worthy investigation.