Natural Products: Alternative Therapeutic Compounds Against Acanthamoeba spp.
Chin Ei Wei, Chong Yoke Yeng, Tooba Mahboob, Lim Chooi Ling, Chandramathi Samudi Raju, Sahapat Barusrux, Veeranoot Nissapatorn

Acanthamoeba, Balamuthia, Naegleria and Sappinia are infective free-living amoeba (FLA), pathogenic to both humans and animals. Acanthamoeba spp. and Balamuthia mandrillaris have similar life cycles as they only exist in 2 forms, cyst and trophozoites. Meanwhile, Naegleria fowleri exists in 3 forms: cysts, trophozoites and flagellated forms. Opportunistic Acanthamoeba spp. gain entry into body via the eyes, nasal passages and through ulcerated skin, which then leads to epithelial keratitis, ocular keratitis and granulomatous amebic encephalitis (GAE) especially among immune-compromised individuals. Despite available anti-Acanthamoeba medications, there have been recurrent reports of toxicity with cases of untreatable GAE. Hence, there is a current demand for safe and effective drugs. Research on plant extracts against Acanthamoeba found that they possess amoebicidal and cytocidal effects, with no or negligible toxicity towards normal human cell lines. Therefore, natural product research should explore further on the discovery of effective drugs for potential use in treating Acanthamoeba and other FLA infections.

Keywords: Acanthamoeba, amoebicidal, cytocidal, natural products, future treatment