Flavonoids as a Natural Treatment Against Entamoeba histolytica

Abstract

Over the past 20 years, gastrointestinal infections in developing countries have been a serious health problem and are the second leading cause of morbidity among all age groups. Among pathogenic protozoans that cause diarrheal disease, the parasite Entamoeba histolytica produces amebic colitis as well as the most frequent extra-intestinal lesion, an amebic liver abscess (ALA). Usually, intestinal amebiasis and ALA are treated with synthetic chemical compounds (iodoquinol, paromomycin, diloxanide furoate, and nitroimidazoles). Metronidazole is the most common treatment for amebiasis. Although the efficacy of nitroimidazoles in killing amebas is known, the potential resistance of E. histolytica to this treatment is a concern. In addition, controversial studies have reported that metronidazole could induce mutagenic effects and cerebral toxicity. Therefore, natural and safe alternative drugs against this parasite are needed. Flavonoids are natural polyphenolic compounds. Flavonoids depend on malonyl-CoA and phenylalanine to be synthesized. Several flavonoids have anti-oxidant and anti-microbial properties. Since the 1990s, several works have focused on the identification and purification of different flavonoids with amebicidal effects, such as, -(-)epicatechin, kaempferol, and quercetin. In this review, we investigated the effects of flavonoids that have potential amebicidal activity and that can be used as complementary and/or specific therapeutic strategies against E. histolytica trophozoites. Interestingly, it was found that these natural compounds can induce morphological changes in the amebas, such as chromatin condensation and cytoskeletal protein re-organization, as well as the upregulation and downregulation of fructose-1,6-bisphosphate aldolase, glyceraldehyde-phosphate dehydrogenase, and pyruvate:ferredoxin oxidoreductase (enzymes of the glycolytic pathway). Although the specific molecular targets, bioavailability, route of administration, and doses of some of these natural compounds need to be determined, flavonoids represent a very promising and innocuous strategy that should be considered for use against E. histolytica in the era of microbial drug resistance.

Antiamoebic activity of plant-based natural products and their conjugated silver nanoparticles against Acanthamoeba castellanii (ATCC 50492)

“…Their mode of antiparasitic action against a common protist Entamoeba histolytica is considered to be a combination of various factors such as inhibition of energetic metabolism, cell proliferation and protein kinases. Moreover, several flavonoids are also known to damage DNA and induce apoptosis in Entamoeba histolytica (Martínez-Castillo et al 2018). PGEA belongs to clerodane diterpene class of natural products.…”

Syrian Hamster as an Animal Model for the Study on Infectious Diseases

“…Entamoeba histolytica is a popular protozoan parasite causing amebiasis in humans that is a major source of morbidity and mortality in the developing countries (133). Parasitic Entamoeba histolytica produces amebic colitis and an amebic liver abscess (ALA).…”

Prevalence and Genetic Identification of Three Entamoeba Species in Pigs in Southeastern China

“…Amoebiasis caused by E. histolytica is the third leading parasitic disease causing morbidity and mortality in humans, causing up to 50, 000 deaths per year, just behind malaria and schistosomiasis [4–7]. The disease is characterized as amebic colitis and liver abscess in humans and animals [3, 8]. Although E. histolytica has not been detected in farmed pigs thus far, and the susceptibility of swine to E. histolytica infection was revealed only under experimental conditions, swine have been considered as potential reservoirs for E. histolytica [9–12].…”