Anti-Giardia activity of Syzygium aromaticum essential oil and eugenol: Effects on growth, viability, adherence and ultrastructure

► Syzygium aromaticum essential oil and eugenol have anti-Giardia activity and inhibit cells attachment. ► Clove oil promotes cell swelling resulting in cell membrane disruption. ► Clove and eugenol induces autophagic death process and encystation like mechanism. ► S. aromaticum essential oil and eugenol have no toxicity on mammalian cells.