Protective effect of Croton caudatus Geisel leaf extract against experimental visceral leishmaniasis induces proinflammatory cytokines in vitro and in vivo.

•Croton caudatus leaf extracts have been evaluated against Leishmania  donovani infection.•Semi-purified Hexane extract was found to be most effective growth inhibitor.•It could alter the biochemical parameters in promastigotes and inhibit amastigotes.•It could induce the release of NO, IL-12 and TNF-α in infected macrophages.•Oral therapy of the active extract could induce the release of IFN-γ in vivo.