PREVALENCE OF AMOEBIASIS

Most of the clinical cases of amoebiasis have been reported in developing countries such as Bangladesh, India, Mali, Algeria, Nepal, Congo, Kenya, South Africa and Cameroon. A study by Morán [4] indicated that intestinal amoebiasis causes more than 55,000 deaths yearly. South Africa alone has the prevalence rate of 12.4%. In 2012, Kenya and Uganda recorded a 58.3% and 19.93% respectively clinical prevalence of intestinal amoebiasis [10,11]. In Abidjan the mortality rate is reported to be 15%. Most of the contributing factors to the complications such as amoebic liver abscess and lethality of the infection is attributed to late diagnosis, poor hygiene, poor water treatment and poor sanitation [2,12,13]. The prevalence of Entamoeba histolytica induce intestinal amoebiasis is reported to be 11.7% in India [14]. Similar prevalence rate (11%) has been reported in children from Bangladesh [15]. In North America, an annual incidence rate of 1 to 5 cases per 100,000 in Mexicans was reported from 1995 to 2000 and 1128.8 to 615.85 per 100,000 inhabitants from 2002 to 2006. Amoebiasis is ranked among the 20 most lethal diseases in Mexico [16,17]. Amoebiasis is endemic in South America: Brazil, Colombia and Ecuador. Also, the diseases are endemic in Australia and parts of Europe (Czech Republic and France) [18]. Figure 1 shows the global intestinal amoebiasis infection endemic areas.

LIFE CYCLE OF ENTAMOEBA HISTOLYTICA

An individual contract an E. histolytica infection by ingesting cysts from contaminated food or water. The mature cyst is resistant to the low pH levels in the stomach, allowing it to withstand gastric acids. Once it reaches the intestine, the intestinal trypsin degrades the cyst wall. Excystation occurs when the cyst arrives in the cecum or the lower part of the ileum.

When a cyst undergoes excystation, it releases eight active trophozoites, which are transported to the large intestine by peristalsis. There, they mature and reproduce by binary fission, feeding on the host's ingested materials.

Trophozoites attach to the mucus lining of the intestine using lectins and secrete proteolytic enzymes that lead to tissue destruction and necrosis. When these parasites enter the bloodstream, they can cause extraintestinal illnesses. As the number of trophozoites increases, some of them stop reproducing and revert to cyst form through a process called encystation. The cysts are then excreted in feces, contaminating food and water, which completes the life cycle [19] (Figure 2).

METHODS

Search Database

The study utilized various electronic databases like Google Scholar, PubMed, ScienceDirect, Booksc.org, Emerald, Scopus, and MEDLINE to search for scholarly publications on medicinal plants with anti-amoebic properties, revealing valuable insights into botanical remedies. A dataset of 70 publications was analyzed using keywords like "amoebiasis," "medicinal plants with anti-amoebic properties," "medicinal plants with activity against Entamoeba histolytica," geographical distribution, and "overview of amoebiasis" and "plants with anti-amoebic properties," offering a thorough comprehension of the illness and possible natural remedies.

Inclusion and Exclusion Criteria

The study analyzed articles published after 2009, excluding those in non-English languages. Articles were reviewed if they had validated botanical names, plant parts, extraction solvents, and medicinal uses. It also noted active phytochemical constituents with anti-amoeba activity.

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines or strategy were used to conduct a thorough review as described by Moher [20].

This strategy is divided into four main stages, as illustrated in Figure 3. These stages include identifying relevant literature, screening the reports, reading the full text to determine eligibility, and applying exclusion and inclusion criteria.

DATA ANALYSIS

The initial search strategy identified approximately one twenty (120) articles. Out of these, ninety (90) studies met all the inclusion criteria for further screening. These studies were in English, had full text available, were related to the anti-amoebic properties of plants, and were dated mainly from 2009 to 2025. Each article was examined in various aspects, including the title, abstract, introduction, methods, results, discussion, and conclusion. Additionally, we checked the inclusion and exclusion criteria, the sampling method, and whether valid instruments were used. Ultimately, eighty (80) studies were deemed relevant; however, ten (10) articles were excluded from the review, leaving seventy (70) articles for further analysis.

RESULTS

Table 1 outlines the scientific name, family name, chemical constituents, extraction method, parts used, and other traditional uses. Approximately twenty-one (21) plants were found to possess anti-amoeba properties.

Table 1. Outline of the scientific name, family name, chemical constituents, extraction method, parts used, and other traditional uses. Approximately twenty-one (21) plants were found to possess anti-amoeba properties.

Figure 4 presents a detailed graph illustrating the distribution of various plant parts, emphasizing key components such as leaves, roots, aerial parts, rhizomes, seeds, stems and fruit. Conversely, Figure 5 offers a captivating depiction of plant family distribution, providing insights into the diversity and interrelationships among different plant groups.

BRIEF LITERATURE ON PLANTS REPORTED TO HAVE ANTI-AMOEBIC ACTIVITY

Many plant-based medicines have been reported to possess anti-amoebic properties, including the following:

Argemone Mexicana Papa, a weed that is native to Mexico and tends to grow in hard places and around farm [59,60]. In an in vitro study under axenic conditions, the methanolic extract of the leaves of A. Mexicana exhibited growth inhibition against the trophozoites of the E. histolytica strain [61]. The Liquid chromatography-mass spectrometry (HPLC-MS) examination of the extract's fractions revealed higher anti-amoebic activity, which pointed to the presence of jatrorrhizine and berberine alkaloids [62].

Allium sativum L., known as garlic, is a potent herb and spice that is derived from a tuber [63]. Allicin concentrations as low as 30 g/ml from garlic extracts can inhibit amoeba growth [23,24]. Also, essential oil from the plant demonstrated a minimum inhibitory concentration (MIC) of 0.3 µg/ml against E. histolytica after 48 hours of anti-amoebic action [64]. Additionally, it was discovered that at lower doses, allicin reduced by 90% the virulence of E. histolytica trophozoites [65].

Asteraceae's Artemisia ludoviciana Nutt. is a rhizomatous, white-woolly perennial herb that can grow up to 1 m tall and has a pungent sagebrush scent. Artemisia ludoviciana's methanolic extract has been shown to have anti-E. histolytica activity with a half maximal inhibitory concentration (IC₅₀) of 82.2 g/mL [47].

Adenophyllum aurantium (L.) is an endemic herb in Mexico of the Asteraceae family that is traditionally known in Mexico as “arnica silvestre” [66]. The ethyl acetate root extract is efficient against Entamoeba histolytica trophozoites as well as in preventing encystment, the growth of liver abscesses, fibronectin adhesion, and erythrophagocytosis, among other harmful stages of the parasite [66]. Thiophenes, which are the primary constituents of the extract and include 5-(4′′-hydroxy-1′′- butynyl)-2-2′-bithiophene and -terthienyl, may be responsible for this effect.

Alpinia galanga (Zingiberaceae), also known as galangal is endemic to Asia specifically Indonesia [67] Chloroform, methanol, and water extracts from Alpinia galanga were tested for their anti-amoebic properties in a study: half maximal inhibitory concentration (IC₅₀) of 55.2 g/ml, the chloroform extracts from Alpinia galanga showed strong anti-amoebic activity against Entamoeba histolytica strains HTH-56: MUTM and HM1: IMSS trophozoites [68].

Boesenbergia rotunda (L.) Mansf., often known as fingerroot, is a plant whose rhizomes are utilized in Asian nations as a spice and herbal remedy [69]. Both the methanol and chloroform extracts from this plant were rated as "active" that is, having a half maximal inhibitory concentration (IC₅₀) of less than 100 g/ml against E. histolytica in a study [70].

Carica papaya L. is considered one of the most nutritious and medicinally important fruit crops of tropical and subtropical regions of the world. According to a study, immature seeds required a minimum inhibitory concentration (MIC) of 62.5 g/mL for the destruction of amoeba parasites, whereas mature seeds needed a minimum inhibitory concentration (MIC) of 7.81 g/mL [71]. One of the bioactive compounds found in C. papaya seeds and leaves is benzyl isothiocyanate (BITC), which has been shown to have anti-amoebic activities. The dysfunctional mitochondria of amoebas are thought to be primarily caused by benzyl isothiocyanate [72]. Again, the extract of papaya seeds that have been macerated in water possesses anti-amoebic properties against Entamoeba histolytica [72,73]. An enzyme called papain present in the plant which aids in the breakdown of proteins has also been proven to be useful in the treatment of amebiasis [71].

Cucurbita pepo L. is a cultigen from Mexico, used for food, medicine, fuel and other purposes. Research in Iraq indicates that the ethanolic extracts of plant seeds exhibited significant anti-amoebic activity against E. histolytica. The study results showed a minimum inhibitory concentration of 500 µg/ml [74].

Curcuma longa L. is a perennial herb characterized by its pointed leaves and funnel-shaped yellow flowers. It typically grows to a height of 3 to 5 feet and is widely cultivated in Asia, particularly in India, China, and other tropical countries [75]. Curcumin is thought to make up 2-5% of this plant. The ethanol extract of the rhizomes has been shown to have anti-amoebic action against Entamoeba histolytica [75,76]. Curcumin exhibits amoebic activity between 100 and 300 g/ml which has a dose-dependent effect on the trophozoites, proliferation, and morphology of E. histolytica [77].

Codiaeum variegatum, often known as the miracle shrub, is a plant that is frequently used as a decorative interior plant [39]. The aqueous leaf extract of C. variegatum was also found to exhibit significant anti-amoebic activity (EC₅₀ of 10.74 µg/mL, 48 hours of incubation) in comparison to the reference drug metronidazole by Njoya [40]. Ceramide is a bioactive lipid that was extracted and discovered by Njoya [40] from the leaves of Codiaeum variegatum (L.). It exhibited anti-amoebic activity against E. histolytica by disrupting the cell cycle including cell differentiation, proliferation, and growth suppression.

Dysphania ambrosioides L. is a Moroccan medicinal plant used in the treatment of various illnesses. The methanolic extract of the leaf includes sitosterol, stigmasterol, octadecanoic acid, scopoletin, and piperoylpiperidine have been shown to have activity against E. histolytica [41]. Additionally, ascaridole, which was shown to be the primary component of the essential oil from D. ambrosioides leaves, demonstrated in vitro efficacy against E. histolytica parasites [78]. The oil showed a half maximal inhibitory concentration (IC₅₀) of 0.7 µg/mL with a partial efficacy to provide consistent protection against the in vivo E. histolytica model. This could be attributed to the rich content of ascaridole epoxide (45.5%) and cis-Ascaridole (34.2%) present in its leaves [79].

Decachaeta incompta (DC.) is a Mesoamerican flowering plant that has historically been utilised in Oaxaca [43]. The extract's half maximal inhibitory concentration (IC₅₀) value for Entamoeba histolytica is 132.4 µg/ml indicating its antiprotozoal activity [44]. The bioactive compounds known as incomptines A (72) and B (73) had an antiprotozoal impact on E. histolytica at 7.9 μM, and 524.6 μM respectively [43]. Enolase, ferrodoxin oxidoreductace, and fructose 1,6-bisphosphate Aldolase are three glycolytic enzymes that incomptine A (IA) has been shown to downregulate, which can disrupt energy metabolism and impair the proliferation of E. histolytica [44].

Euphorbia hirta Linn is found all over the world. It is commonly found in lowland areas, paddy fields, gardens, waste areas, and by the sides of roads [80]. The results of an enzyme activity test revealed that the methanol fraction had an inhibitory effect on E. histolytica’s RNase, aldolase acid, and alkaline phosphatase activities [81]. This shows that the plant inhibits enzymes necessary for E. histolytica's survival or metabolism.

Geranium mexicanum Kunth., belongs to the Geraniaceae family, and is also known as cut leaf [47]. Its aerial portions when extracted with methylene chloride contained flavonoids which are effective against E. histolytica [27]. The flavonoids include Kaempferol, tiliroside, and epicatechin. The most effective flavonoid is epicatechin, which had greater efficacy than metronidazole in a study by Ojuromi [53].

Lepidium virginicum L., commonly known as Virginia pepper weed or least pepperwort, is an herbaceous plant belonging to the mustard family (Brassicaceae). This plant is native to much of North America, including most of the United States, Mexico and southern regions of Canada [82]. Lepidium virginicum L. was shown to be highly efficient against Entamoeba histolytica in a study by Ojuromi [83], with a collective mean half maximal inhibitory concentration (IC₅₀) of 198.63 µg/mL. Also, the methanolic extract of the roots of Lepidium virginicum L. was studied using a bioassay-guided approach, and the results revealed the compound benzyl glucosinolate as having amoebicidal action (IC₅₀ = 50.0 µg/ml) [27,48].

Lippia graveolens Kunth, a species of flowering plant in the Verbenaceae family, is native to the southwestern United States (Texas and southern New Mexico), Mexico, and Central America as far south as Nicaragua. The antiprotozoal action of Lippia graveolens extracts against Entamoeba histolytica is directly correlated with the content of the flavonoids identified in this plant. Significant growth inhibition of E. histolytica was exhibited by the isolated and purified flavonoids from L. graveolens (52% to 97% at a concentration of 150 g/mL) [84].

Ruta chalepensin Pers. typically grows up in the mountains to an elevation of 1000 meters above sea level. With a self-supporting growth habit, this tall subshrub (0.4-1 m tall) has light green leaves and a slender, wooden stem [51]. The parasite Entamoeba histolytica, the main cause of amoebiasis in humans, was found to be susceptible to the antiprotozoal effects of chalepensin (3-prenylated furanocoumarin) [52]. This was isolated from the methanolic extract of the aerial parts of R. chalepensis. At a concentration of 150 g/mL, 84.66% growth inhibition was seen against E. histolytica.

Rubus coriifolius Liebm is a Mesoamerican species of brambles in the rose family. It grows in central and southern Mexico (from Chiapas as far north as Tamaulipas) and Central America (Guatemala, Honduras, Nicaragua) [85]. The dichloromethane-methanolic extract has demonstrated the highest efficacy among the crude fractions against Entamoeba histolytica, exhibiting a half maximal inhibitory concentration (IC₅₀) value of 55.6 µg/mL [47]. Epicatechin, catechin, nigaichigoside, -sitosterol-3-O-D-glucopyranoside, hyperin, gallic acid, and ellagic acid, among other isolated compounds, had half maximal inhibitory concentration (IC₅₀) values of 1.9, 65.5, 111.9, 82.16, 143.6, 220, and 56.5 µg/mL against E. histolytica, respectively [47].

In Mexican traditional medicine, Salvia polystachya Ort., often known as chia, is used as a purgative, antigastralgic, antimalarial, antipyretic, antihemorrhagic, and for heartburn and dysentery [44,55]. Diterpenoids were extracted from Salvia polystachya Cav. leaves and their antiprotozoal activity were assessed [27,44,55]. Linearolactone was found to be the most effective derivative against E. histolytica, with half maximal inhibitory concentration (IC₅₀) values of 22.9µg/mL.

Xylopia aethiopica A. is also known as negro pepper, African pepper, Guinea pepper and many more. Lowland rain forests, wet fringe forests, savanna regions, and coastal regions of Africa are its native habitats [56]. According to a study, xylopic acid and geraniin are effective against E. histolytica, with half maximal inhibitory concentration (IC₅₀) values of 4.80 g/mL (13.30 mM) and 34.71 g/mL (36.44 mM), respectively [86].

Zanthoxylum liebmannianum P. Wilson, a member of the Rutaceae family, is also referred to as pickleweed [27]. Zanthoxylum liebmannianum was one of the 80 species studied that showed positive activity against E. histolytica [86]. Flavonoids, lignans, and sterols were present in the ethanolic leaf extracts that showed effectiveness against E. histolytica [87].

DISCUSSION

The use of medicinal plants is on the rise in both developed and developing countries. The underlying principle their use is that these plants contain specific biologically active substances that affect the metabolic processes in humans [87].

After researching the relevant databases, it was found that approximately twenty-one (21) medicinal plants exhibit anti-amoebic activity against Entamoeba histolytica. These plants contain specific phytochemicals that can inhibit the growth of this organism. Notable among these phytochemicals are curcumin, allicin, and papain [27].

The study reviewed the distribution of parts of the plants used in preparation for treatment against E. histolytica included leaves (61%), rhizomes (13%), roots (9%), seeds (9%), stem (4%) and fruits (4%). The most used plant part was leaves because of their rich concentration of bioactive compounds and their ease of accessibility. Additionally, the leaves rapid regenerative capabilities contribute to the conservation of endangered species [88].

The Astraceae (14%) and Zingiberaceae (14%) families contained the most plants that are effective against E. histolytica, followed by the Euphorbiaceae (10%) and Rutaceae (10%) families as reported in Figure 5. Both the Asteraceae and Zingiberaceae families are rich in terpenoids and flavonoids, which are known to exhibit activity against E. histolytica [89].

Maceration was the most commonly used extraction method [90]. It involves soaking plant materials in a liquid for an extended period to effectively extract desired compounds [91]. Its popularity stems from its simplicity and lack of specialized equipment. The prolonged interaction enhances the extraction process, yielding a rich array of beneficial substances [92]. Recent studies by Sankeshwari [93] showed that cold maceration can extract compounds with improved antimicrobial properties, offering the potential for more effective natural remedies. These reports dovetails with our analysis as seen in Table 1, maceration was the most reported method of preparation.

Argenone Mexicana, Allium Sativum, and Artemisia Ludoviciana are plants noteworthy for their effective against E. histolytica. Crude extracts can be obtained using solvents such as methanol, ethanol, and water. Allium Sativum contains allicin, which has been found to reduce the virulence of E. histolytica trophozoites by 90% [47].

Also in vivo study has shown that Adenophyllum aurantium can help prevent liver abscesses [67] associated with infection. The chloroform extracts of Alpinia galanga had strong anti-amoebic activity, with an IC₅₀ value of 55.2 µg/ml, making it more effective than other solvents like methanol and water. Both the methanol and chloroform extracts from Boesenbergia pandurata were considered "active," with an IC₅₀ of less than 100 µg/ml against E. histolytica [27,28]. Curcuma longa, Carica papaya, Cucurbita pepo, and Codiaeum variegatum have been identified as possessing anti-amoeba activity. Curcumin, a key phytochemical in Curcuma longa, is recognized for its pharmacological effects. The seeds and leaves of Carica papaya, when macerated in water, release the compound Benzyl isothiocyanate, which contributes to mitochondrial dysfunction in E. histolytica. Although primarily regarded as a decorative plant, Codiaeum variegatum has also demonstrated the ability to disrupt the cell membrane of this E. histolytica [39,40].

Dysphania ambrosioides, Decachaeta incompta, Euphorbia hirta, and Geranium mexicanum are all medicinal plants noteworthy for their effectiveness against E. histolytica. Dysphania ambrosioides contains essential oil rich in ascaridole, while Decachaeta incompta contains incomptine A, which disrupts the energy metabolism and impairs the proliferation of E. histolytica. Euphorbia hirta negatively affects the function of enzymes, such as alkaline phosphatase, which are essential for the survival and metabolism of E. histolytica. A study also compared the efficacy of Geranium mexicanum with that of metronidazole; the results showed that Geranium mexicanum exhibited higher efficacy than metronidazole in an in vitro study [53].

Lepidium virginicum, Lippia graveolens, Ruta chalepensin, and Rubus coriifolius have demonstrated activity against Entamoeba histolytica. Lepidium virginicum contains the phytochemical benzyl glucosinolate, which has been shown to possess amoebicidal properties. Additionally, Ruta chalepensin, which contains the active compound chalepensin, is effective in inhibiting the growth of E. histolytica [51,52].

Salvia polystachya, Xylopia aethiopica, and Zanthoxylum liebmannianum are well-known medicinal plants. Aside from their uses for various conditions, such as their anti-inflammatory and anti-hypertensive properties, these plants have demonstrated activity against Entamoeba histolytica.  Among the phytochemicals found in Salvia polystachya, linear lactone is noted to be the most effective against E. histolytica. xylopic acid, extracted from Xylopia aethiopica, has an IC₅₀ value of 4.80 µg/ml, indicating its activity against this parasite. Additionally, the ethanolic leaf extract of Zanthoxylum liebmannianum has also shown efficacy against E. histolytica [27,58].

IMPLICATIONS FOR SUSTAINABILITY

The anti-amoeba properties found in specific plant families have significant implications across various fields. The predominance of Asteraceae and Zingiberaceae, each making up about 14%, along with Euphobiaceae (10%) and Rutaceae (10%) suggests clear targets for pharmaceutical research, thereby guiding drug discovery initiatives. This focused distribution indicates that these families are likely to share common biochemical pathways or molecular structures that confer their anti-amoeba properties, potentially speeding up the discovery of new therapeutic compounds. These results call for focused conservation efforts, especially for these four families, which together represent 48% of identified anti-amoeba plants. This data also provides empirical support for certain traditional medicinal practices, especially those utilizing species from these dominant families.

From an economic perspective, this distribution pattern reveals specific opportunities for sustainable cultivation and the advancement of biotechnology, especially in regions where these families occur naturally. The clear identification of high-value plant families enables a more efficient use of research resources and supports evidence-based conservation strategies. It also facilitates the cultivation and development of biotechnology, especially in regions where these families naturally occur.

CONCLUSION

The results suggest plants as a promising source of compounds to combat amoebiasis caused by Entamoeba histolytica. Astraceae and Zingiberaceae families contain most plants that are effective against E. histolytica. Further research is needed to establish their mechanisms of action, toxicities and clinical potentials. Overall, the study offers a thorough repository for the scientific community engaged in ethnobotany and drug discovery and development from medicinal plants.

DECLARATIONS

Authors’ Contribution

This work was carried out in collaboration between all authors. Samuel Korsah and John Antwi Apenteng designed the study, performed the statistical analysis, and wrote the first draft of the manuscript. Miriam Tagoe and Nathaniel Nene Djangmah Nortey, Anna Kwarley Quartey managed the analysis of the study. Prince Baffour Adofo and Derick Kontoh managed the literature searches. All authors read and approved of the final manuscript.

FUNDING

This work was jointly funded by the authors with no external funding.

ACKNOWLEDGMENT

The authors wish to thank the Ghana Health Service and the Ghana Association of Medical Herbalist (GAMH) for their support in the study.

DATA AVAILABILITY

The data used to support the findings of this study are included in the article and available from the corresponding author upon request.

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  Table 1
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  Table 2