Besides the determination of its LD50 value, the cytotoxicity against KB and P388 cell lines and the toxicity on isolated guinea pig auricle of malagashanine and its combination with chloroquine were assessed. Malagashanine alone was devoid of cytotoxicity and cardiac effect on isolated auricle, and importantly, when combined to chloroquine, did not affect the inherent toxicity and cardiac toxicity of this antimalarial agent.