Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X www.turkjphysiotherrehabil.org 12056 DETECTION OF THE ACTIVE COMPOUNDS IN THE AQUEOUS EXTRACT OF CITRULLUSCOLOCYN THIS L. SEEDS BY GC-MS TECHNIQUE AND THEIR EFFECT ON REDUCING CYST NUMBER OF THE AMOEBIC DYSENTERY PARASITE IN VIVO. Hussam Saad H. Alkhalidi 1 , Huda Jasim M. Altameme 2 , Ahmed Khudhair Al-Hamairy 3 1,2,3 College of Science for Women, University of Babylon, Biology Dept. Hilla, Iraq. Hussam.hussein@student.uobabylon.edu.iq ABSTRACT: This study was carried out In vivo to investigate the effect of the active compounds of CitrulluscolocynthisL. seed aqueous extract revealed by the Chromatography-Mass Spectrometry analysis (GC-MS) on the reduction of the cysts of Entamoeba histolytica and compared it with metronidazole in albino mice(Balb/c). The mice infected with a cyst of the parasite(1000cyst/ml 3 ) were dosed with the plant extract in three concentrations (100, 200, 300) mg/ml After confirming the presence of infection, the stool is examined every 24 hours for 10 days to note the changes in the cysts parasite numbers after dosing with the extract. The results revealed that the aqueous extract of Citrulluscolocynthiswas effective in reducing the number of cysts in mice, as it recorded the highest percentage of killing cysts at a concentration of 300 mg/ml on the third day of the experiment, and thus it is equal to the effect of the Metronidazole that killed the parasite on the same day at a concentration of 300 mg/ml, while the other of the concentrations of the plant extract (100,200) mg/ml had a significant effect in reducing cyst numbers during its duration. The experiment was compared with the control group treated with distilled water. Keywords:GC,MS,Phytochemicals,CitrulluscolocynthisL.,Medicines,uses,Entamoeba histolytica. I. INTRODUCTION. Plants have been known to humanity for a long time ago, and they have been used in a variety of forms throughout history. In their quest for food and success in overcoming human misery, Neanderthals started to differentiate between plants that were ideal for medicinal purposes and those that had no medicinal effect. Plants and humans formed a partnership, and many plants have been used as medicines (Kumar et al., 2015). CitrulluscolocynthisL. is a member of the Cucurbitaceae (squash) family, and its common names include colocynth, bitter gourd, bitter apple, and bitter cucumber(De Smet, 1997). It's a long-lived perennial that grows wild in xerophytic deserts and produces oil- and protein-rich seeds(Sawayaet al., 1983). The Sahara and Arabian deserts, Sudan, and Southern Asia, including Pakistan, India, and the Southern Islands, are all home to the plant(Al- Ghaithiet al., 2004; Krishnarajuet al., 2005; Upadhyay et al., 2007; Gurudeebanet al., 2010). Diabetes, constipation, leprosy, asthma, bronchitis, jaundice, knee pain, cancer, and mastitis are conditions commonly treated by C. colocynthis of worldwide(Sultan et al., 2010),and Medicinal uses of this herb are listed in the Local System Registry of Medicines in Pakistan, India, China, Africa, and Asia, including indigestion, dysentery, gastroenteritis, and colic pains, as well as colds, coughs, dental discomfort, wounds, and diabetes(Gurudeebanet al., 2011).C.colocynthis is known for its antibacterial antioxidant, free radical scavenging, and larvicidal effects, in addition to its common folk medicine uses as a laxative or diuretic or for external applications(Tarrafet al., 2019). Diarrhea is still the second cause of death in children under the age of five worldwide(Organization, 2009).Leon- Coria et al.,(2018)emphasized the E.histolytica is a parasitic human protozoan that causes amebiasis and were responsible for about 11,300 deaths worldwide in 2013. Therefore, the research aimed to find out the effect of the