# Potential Role of Plant Extracts and Phytochemicals Against Foodborne Pathogens
## 5 Plant Extracts and Phytochemicals against Parasites Causing Foodborne Diseases
### Entamoeba histolytica  
Amoebiasis is a ubiquitous gastrointestinal disorder most prevalent in less developed countries with poor sanitation and socioeconomic status, affecting about 12% of global population [230]. It is known to be the third leading cause of mortality [231; 232; 233]. The causative agent of amoebbiasis is _Entamoeba histolytica_, which is associated with typical symptoms of amoebic dysentery, abdominal cramps, bloating or tenderness and stomachache [234; 235]. Among the currently available chemotherapeutics, metronidazoleze is an effective amoebicide, but is associated with unwanted side-effects like carcinogenesis, mutagenesis, nausea and vomiting [236; 237]. The stratagem of utilizing natural drugs in antiamoeba therapy traces back to the pre-historic era. For instance, emetine isolated from _Cephaelis ipecacuanha_ (Brot.) A.Rich. is used as a front line anti-amoebic drug [238]. Currently, a large population is dependent on traditional therapeutics for the management of various diseases [18; 25; 239]. Medicinal plant and herbal drugs represent an indispensable part of the traditional medicine practiced in many countries owing to low costs, frequent availability, biosafety and ancestral knowledge [240; 241; 242]. Hence, in search of more effective drugs, traditionally used natural products are of great importance. Several natural products and isolated compounds have been scientifically validated for effective eradication of _Entamoeba histolytica_, for potential drug development. For instance, bruceantin, a potent amoebicide from _Brucea antidysenterica_ [PERSON]. exhibited IC\({}_{50}\) of 0.018 \(\mu\)g/mL [243], parthenin from _Parthenium hysterophorus_ L. [244], extracts and isolated compounds from _Brucea javanica_ ([PERSON]) [PERSON]. fruits and _Sinarouba amara_ Aubl. [245] and alkaloids from _Alstonia angustifolia_ Wall. ex A.DC. roots [246] were extensively studied against _E. histolytica_. [PERSON] et al. investigated the effect of _Morinda morindoides_ [PERSON]. leaves extracts and isolated compounds against _E. histolytica_[247]. The crude methanolic extract and aqueous decoction showed significant anti-amoeba action with IC\({}_{50}\) values of 1.7 and 3.1 \(\mu\)g/mL, respectively. Among the isolated compounds, kempferol, apigenin, luteolin, apigenin-7-O-glucose and luteolin-7-O-glucose exhibited IC\({}_{50}\) values of 10.3, 12.7, 17.8, 22.3 and 37.4 \(\mu\)g/mL, respectively against _E. histolytica_. [PERSON] et al. evaluated forty-five Congolese plant extracts used in traditional medicine against _E. histolytica_. Among the tested samples, _Mangifera indica_ L., _Rauwolfia obscura_ K.Schm., _Carica papaya_ L., _Euphoria hirta_ L., _Hymenocardiia acidia_ Tull., _Jatropha curcas_ L., _Maprounae africana_ Mull. Arg., _Paropsa brazzeana_ Baill., _Psidium guajava_ L., _Cryptolepis sanguilonenta_ (Lindl.) Schltr. and _Qussia africana_ (Baill.) Baill. were highly active with IC\({}_{50}\) values of 7.81, 31.5, 7.81, 31.25, 31.25, 31.25, 7.81, 7.81 and 31.5 \(\mu\)g/mL, respectively [248]. In another study, [PERSON] et al. investigated the antiamoebic potentials of an herbal formulation containing _Zingiber officinala_, _Berberis aristata_, _Beorhavia diffusa_ L., _Tinospora cordifolia_ (Wild.) Miers and _Terminalie chebula_ extracts. Among these plant extracts, _Berberis aristata_ and _Tinospora cordifolia_ showed IC\({}_{50}\) values of 100 and 1000 \(\mu\)g/mL, respectively. All these plants in a combined formulation exhibited an IC\({}_{50}\) of 1000 \(\mu\)g/mL. The herbal formulation was also tested against some enzymes of _E. histolytica_ including DNase, RNase, aldolase, alkaline, acid phosphatases and \(\alpha\)-amylase that are known to play a significant role in the virulence and invasiveness of the parasite. Results confirmed various degrees of inhibition of these enzymes [249]. Owing to the traditional use of _Salvia polystachya_ Cav. for the treatment of dysentery in the Mexican traditional medicine, [PERSON] et al.