Amoebiasis, caused by Entamoeba histolytica (E. histolytica), is the third
leading cause of health problems in developing countries and affects more than 10% of
the world’s population. If left untreated, amoebiasis causes severe complications
including hepatic and intestinal tissue destruction. According to World Health
Organization (WHO), approximately 80% of the people in less-developed countries
still rely on traditional medicine for their healthcare needs. In different parts of the
world, plant extracts obtained from numerous plants have been used in the indigenous
system of medicine for the treatment of dysentery. To apply these remedies to the
rational scientific use of herbal medicines, studies on antiamoebic drugs mainly
focused on natural products associated with folklore medicine. Plant extracts have been
tested, and several natural products have been isolated from the active fractions,
leading to the characterization and extensive biological studies of the isolated
compounds. This book chapter reviews the noticeable crude extracts from medicinal
plants tested for antiamoebic activities and isolated natural products that have been
evaluated for antiamoebic activities in the last five decades. Most of these compounds
with known structures belong to alkaloids, terpenoids, quassinoids, flavonoids, iridoids,
and other phenolic compounds obtained from higher plants. These natural products
showed activity against E. histolytica and other protozoa in vitro, and some of the
natural products have been tested in vivo. Only a very few of them have been tested
clinically. Herein, we report the traditional user’s knowledge, pharmacological activity,
mechanism of action, toxicity, and other properties of antiamoebic natural products.
Keywords: Amoebiasis, Antiamoebic, Alkaloids, E. histolytica, Flavonoids,
Iridoids, Natural products, Quassinoids, Terpenoids.
