Natural Remedies in the Fight Against Parasites

past 15 years [ 1 , 2 ]. Nearly 90% of the malaria cases and deaths occur in Sub‐Saharan Africa in

2015, loading a heavy socio‐economic burden to this poorly developed region [ 1 ].

Malaria is caused by parasitic protozoa of the genus Plasmodium. Hundreds of Plasmodium

species have been identified to infect reptiles, birds and mammals, including rodents and

primates. Four Plasmodium species pluralis (spp.), P. falciparum, P. vivax, P. malariae and P. ovale,

are known to infect man, though other malarial species of non‐human primates occasionally

infect human as well. Among these species, P. falciparum is the most deadly and P. vivax,

the most prevalent. P. falciparum invades both young and mature erythrocytes and provokes

malignant disease symptoms. Prevalent mainly in Africa, P. falciparum accounts for ~40% of

the clinical cases on a global basis [ 1 ]. In contrast, P. vivax prefers invading young erythrocytes

and causes benign symptoms; it has a wider geographical distribution than P. falciparum and

is responsible for half of the total reported cases [ 1 ].

To complete its life cycle, the malaria parasite requires a female mosquito as the transmission

vector and a vertebrate host (Figure 1 ). When a blood meal is taken, a parasite‐infected mos‐

quito inoculates sporozoites into the human host to start the exo‐erythrocytic phase, in which

sporozoites infect hepatocytes and mature into schizonts. Of note, in parasites such as P. vivax

and P. ovale, a dormant stage, namely hypnozoites, can maintain in hypatic cells for weeks or

even years before invading the bloodstream. Rupture of schizonts releases merozoites, which

Figure 1. The life cycle of malaria parasites. Malaria parasites require a transmission vector (e.g., mosquito) and a

vertebrate host (e.g., human) to complete their life cycle. The exo‐erythrocytic and intra‐erythrocytic phases occur in the

vertebrate host, and the sporogonic phase occurs in the transmission vector.

184 Natural Remedies in the Fight Against Parasites