Lamblia Trophozoites Research Articles

Polyphenolic extract from Punica granatum peel causes cytoskeleton-related damage on Giardia lamblia trophozoites in vitro.

BackgroundDiarrheal diseases caused by protozoa have a great impact on human health around the world. Giardia lamblia is one of the most common flagellates in the intestinal tract. Factors such as adverse effects to first-line drugs or the appearance of drug-resistant strains, make it necessary to identify new treatment alternatives. Agroindustry waste, like pomegranate peel, are a source of phenolic compounds, which possess antiparasitic activities. In vivo studies demonstrated antigiardiasic potential by reducing cyst shedding and protecting intestinal cells; however, they did not identify the compounds or elucidate any mechanism of action in the parasite. The objective of this study is to identify potential molecular targets and to test the in vitro effects of polyphenols from Punica granatum on Giardia lamblia.MethodsThe in vitro antigiardial potential of polyphenolic extract from pomegranate peel (Punica granatum L.) obtained using microwave-ultrasound methodology was evaluated on Giardia lamblia trophozoites. Extract phytochemical identification was performed by HPLC/MS analysis. The effect of polyphenolic extract on growth and adhesion capacity was determined by parasite kinetics; morphological damage was evaluated by SEM, alteration on α-tubulin expression and distribution were analyzed by western blot and immunofluorescence, respectively.ResultsThe pomegranate peel extract showed the presence of ellagitannins (punicalin and punicalagin, galloyl-dihexahydroxydiphenoyl-hexoside), flavones (luteolin), and ellagic acid, that caused an inhibitory effect on growth and adhesion capacity, particularly on cells treated with 200 µg/mL, where growth inhibition of 74.36%, trophozoite adherence inhibition of 46.8% and IC50 of 179 µg/mL at 48 h were demonstrated. The most important findings were that the extract alters α-tubulin expression and distribution in Giardia trophozoites in a concentration-independent manner. Also, an increase in α-tubulin expression at 200 µg/mL was observed in western blot and diffuse or incomplete immunolabeling pattern, especially in ventral disk. In addition, the extract caused elongation, disturbance of normal shape, irregularities in the membrane, and flagella abnormalities.DiscussionThe pomegranate peel extract affects Giardia trophozoites in vitro. The damage is related to the cytoskeleton, due to expression and distribution alterations in α-tubulin, particularly in the ventral disk, a primordial structure for adhesion and pathogenesis. Microtubule impairment could explain morphological changes, and inhibition of adhesion capacity and growth. Besides, this is the first report that suggests that ellagic acid, punicalin, punicalagin and luteolin could be interactioning with the rich-tubulin cytoskeleton of Giardia. Further investigations are needed in order to elucidate the mechanisms of action of the isolated compounds and propose a potential drug alternative for the giardiasis treatment.

Discovery of Benzopyrrolizidines as Promising Antigiardiasic Agents.

Current treatments for giardiasis include drugs with undesirable side effects, which increase the levels of therapeutic desertion and promote drug resistance in the parasites. Herein, we describe the antigiardiasic evaluation on Giardia lamblia trophozoites of a structurally diverse collection of 74 molecules. Among these scaffolds, we discovered a benzopyrrolizidine derivative with higher antigiardiasic activity (IC50 = 11 µM) and lower cytotoxicity in human cell cultures (IC50 = 130 µM) than those displayed by the current gold-standard drugs (metronidazole and tinidazole). Furthermore, this compound produced morphologic modifications of trophozoites, with occasional loss of one of the nuclei, among other changes not observed with standard giardicidal drugs, suggesting that it might act through a novel mechanism of action.

A Morinda royoc Root Extract and Fractions Exhibit Antigiardial Activity without Affecting Cell Viability.

Background:The gastrointestinal parasite Giardia lamblia causes giardiasis. Its treatment with standard drugs produces side effects and improper treatment can generate resistant strains. New antigiardial compounds are needed. An analysis was done to identify the antigiardial activity of Morinda royoc, a plant used in traditional Mayan medicine to treat stomach and bowel pain. We aimed to assess the efficacy of M. royoc roots against G. lamblia and their effect on cells viability.Methods:A methanol extract was done of the root and then fractionated. The extract and fractions were tested in vitro on G. lamblia trophozoites and their effect on cell viability was quantified by flow cytometry. The active extract and fractions were analyzed by gas chromatography–mass spectrometry and high-performance liquid chromatography.Results:The hexane fraction exhibited potent activity against G. lamblia (IC50 = 0.08 μg/mL). Its principal component was an anthraquinone-type compound. None of the fractions were toxic to human promyelocytic leukemia, chronic myelogenous leukemia and human mononuclear cells.Conclusion:The medicinal plant M. royoc contains promising bioactive agents with antigiardial activity and deserves further research.

Pomegranate Peel Extract Is a Potential Alternative Therapeutic for Giardiasis.

Giardiasis is a major diarrheal disease affecting approximately 2.5 million children annually in developing countries. Several studies have reported the resistance of Giardia lamblia (G. lamblia) to multiple drugs. Therefore, identifying an effective drug for giardiasis is a necessity. This study examined the antiparasitic effect of Punica granatum (pomegranate) and evaluated its therapeutic efficacy in rats infected with G. lamblia. In vitro study showed high efficacy of pomegranate peel ethanolic extract in killing G. lamblia cysts as demonstrated by eosin vital staining. We showed that treating infected rats with pomegranate extract resulted in a marked reduction in the mean number of G. lamblia cysts and trophozoites in feces and intestine respectively. Interestingly, the number of G. lamblia trophozoites and cysts were significantly lower in the pomegranate extract-treated group compared to the metronidazole-positive control group. Moreover, pomegranate extract treatment significantly induced nitric oxide (NO) and reduced serum IL-6 and TNF-α, compared to infected untreated rats. Histological and scanning electron microscopy (SEM) examination of the jejunum and duodenum of pomegranate extract-treated animals confirmed the antiparasitic effect of the extract, and demonstrated the restoration of villi structure with reduction of villi atrophy, decreased infiltration of lymphocytes, and protection of intestinal cells from apoptotic cell death. In conclusion, our data show that the pomegranate peel extract is effective in controlling G. lamblia infections, which suggests that it could be a viable treatment option for giardiasis.

Virtual Screening of FDA-Approved Drugs against Triose Phosphate Isomerase from Entamoeba histolytica and Giardia lamblia Identifies Inhibitors of Their Trophozoite Growth Phase.

Infectious diseases caused by intestinal protozoan, such as Entamoeba histolytica (E. histolytica) and Giardia lamblia (G. lamblia) are a worldwide public health issue. They affect more than 70 million people every year. They colonize intestines causing primarily diarrhea; nevertheless, these infections can lead to more serious complications. The treatment of choice, metronidazole, is in doubt due to adverse effects and resistance. Therefore, there is a need for new compounds against these parasites. In this work, a structure-based virtual screening of FDA-approved drugs was performed to identify compounds with antiprotozoal activity. The glycolytic enzyme triosephosphate isomerase, present in both E. histolytica and G. lamblia, was used as the drug target. The compounds with the best average docking score on both structures were selected for the in vitro evaluation. Three compounds, chlorhexidine, tolcapone, and imatinib, were capable of inhibit growth on G. lamblia trophozoites (0.05–4.935 μg/mL), while folic acid showed activity against E. histolytica (0.186 μg/mL) and G. lamblia (5.342 μg/mL).

Prevalence of Giardia Lamblia among Children Attended at SOS Hospital

Background: Giardia lamblia is considered to be one of the leading causative agents of diarrhea, especially in children. Epidemiological surveys have shown that parasitic diarrhea in children is primarily due to G. lamblia infection Giardia lamblia can result in reduced physical fitness, delayed growth and gastrointestinal problems, such as abdominal pain, vitaminB12 deficiency and malabsorption about 200 million people have symptomatic giardiasis. In areas where sanitation and hygiene are poor the disease is most severeObjective: To identify prevalence of giardia lamblia among children attended at SOS hospital in Mogadishu Somalia.Methods and Materials: study was descriptive cross-sectional study conducted in SOS hospital, Mogadishu-Somalia during May 2020 to june2020; 50 stool samples were collected from the patients attending at SOS hospital. The Stool was to identify under microscope Examination used for wet preparation method. The study used SPSS (version 20.0) for analysis, and results were presented in frequencies, percentage, and bar charts.Results: 50 sample stools were collected from patient with suspected parasitic infection SOS hospital different age groups and both sexes were covered. When we made diagnosis test of stool ni 8(16%) were giardia lamblia cyst seen also when we made diagnosis test ni 2(4%) were giardia lamblia trophozoite, during diagnosing I have seen other parasites, 9(18%) were Ascaris lubricoides ova seen, 7(14%) were T.T ova seen, 5(10%) were H.nan egg seen, 4(8%) were E.histolytic, when we made diagnose test of giardia lamblia in 15(30%) were negative.Conclusion: the results from the study showed high rate of giardia lamblia infection and also another parasite. We have identified domestic factors like mother education, no. of under-five children in the family, low SES and peri-domestic factors like lack of solid waste collection and visible sewage near the house. We emphasize the pro-vision of health care services, personal education and environmental hygiene by both governmental and non-governmental organization to reduce this high prevalence. Regular diagnosis should be available and treatment should be provided for infected and vulnerable communities.

Discovery and Preclinical Development of Antigiardiasis Fumagillol Derivatives.

Giardiasis, caused by the intestinal parasite Giardia lamblia, is a severe diarrheal disease, endemic in poverty-stricken regions of the world, and also a common infection in developed countries. The available therapeutic options are associated with adverse effects, and G. lamblia resistance to the standard-of-care drugs is spreading. Fumagillin, an antimicrosporidiosis drug, is a therapeutic agent with potential for the treatment of giardiasis. However, it exhibits considerable, albeit reversible, toxicity when used to treat immunocompromised microsporidiosis patients. Fumagillin is also a highly unstable compound. To address these liabilities, we designed and synthesized stable fumagillol derivatives with lower levels of permeation across polarized epithelial Caco-2 cells and better potency against G. lamblia trophozoites than fumagillin. Metronidazole-resistant G. lamblia strains were also susceptible to the new fumagillol derivatives. In addition, these compounds were more potent against the amebiasis-causing parasite Entamoeba histolytica than fumagillin. Two compounds exhibited better thermal and acid stability than fumagillin, which should prolong the drug shelf life and reduce compound degradation in the stomach. Studies with a mouse model of giardiasis with the most stable compound, 4-(((((3R,4S,5S,6R)-5-methoxy-4-((2R,3R)-2-methyl-3-(3-methylbut-2-en-1-yl)oxiran-2-yl)-1-oxaspiro[2.5]octan-6-yl)oxy)carbonyl)amino)benzoic acid (compound 9), revealed that it had better efficacy (effective dose [ED]) than fumagillin at both the fully curative dose (the 100% ED) of 6.6 mg/kg of body weight and a 50% ED of 0.064 mg/kg. Plasma pharmacokinetics revealed the slow absorption of compound 9 through the gut, consistent with the in vitro characterization in Caco-2 cells. An acute-dose study yielded a maximum tolerated dose (MTD) of 1,500 mg/kg, 227-fold higher than the fully curative dose. Thus, along with improved stability, compound 9 also exhibited an excellent therapeutic window.

Metabolomic Profiling of Wildtype and Transgenic Giardia lamblia Strains by 1H HR-MAS NMR Spectroscopy.

Giardia lamblia, a causative agent of persistent diarrhea in humans, domestic animals, and cattle, is usually treated with nitro compounds. Consequently, enzymes involved in anaerobic nitro reduction have been investigated in detail as potential targets. Their role within the normal metabolic context is, however, not understood. Using 1H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy, we analyzed the metabolomes of G. lamblia trophozoites overexpressing three nitroreductases (NR1–NR3) and thioredoxin reductase (TrxR), most likely a scavenger of reactive oxygen species, as suggested by the results published in this study. We compared the patterns to convenient controls and to the situation in the nitro drug resistant strain C4 where NR1 is downregulated. We identified 27 metabolites in G. lamblia trophozoites. Excluding metabolites of high variability among different wildtype populations, only trophozoites overexpressing NR1 presented a distinct pattern of nine metabolites, in particular arginine catabolites, differing from the respective controls. This pattern matched a differential pattern between wildtype and strain C4. This suggests that NR1 interferes with arginine and thus energy metabolism. The exact metabolic function of NR1 (and the other nitroreductases) remains to be elucidated.

Diagnosis of parasitic infections in vermiform appendix in patients with appendicitis in Kirkuk city, Iraq

The present study is conducted in Kirkuk city, Iraq; between July to December 2018. Within this period 197 resected appendix are examined to investigate the parasitic infections that may associated with appendicitis. Direct with concentrated methods are used in luminal content examinations. Also, histological examination of haematoxylin and eosin stained tissue sections is performed to diagnose the parasitic infections in the lumen and within the appendix tissue. The parasitic infection reported in 12.69% cases included four species, as well as a mixed infection. Entamoeba histolytica (trophozoite and cyst), Giardia lamblia (trophozoite and cyst), Cryptospordium sp.(oocyst) and Enterobious vermicularis (adult worm and ova) are recorded. The most common determined parasite is E. histolytica (8.63%). The parasitic infection within the resected appendix reported in females (8.12%) more than males (4.57%). The parasitic infections in the study are prevalent in patients within the age groups 13 to 18 years and 19 to 24 years (3.55% for each one).

Increased Innate Lymphoid Cell 3 and IL-17 Production in Mouse Lamina Propria Stimulated with Giardia lamblia.

Innate lymphoid cells (ILCs) are key players during an immune response at the mucosal surfaces, such as lung, skin, and gastrointestinal tract. Giardia lamblia is an extracellular protozoan pathogen that inhabits the human small intestine. In this study, ILCs prepared from the lamina propria of mouse small intestine were incubated with G. lamblia trophozoites. Transcriptional changes in G. lamblia-exposed ILCs resulted in identification of activation of several immune pathways. Secretion of interleukin (IL)-17A, IL-17F, IL-1β, and interferon-γ was increased, whereas levels of IL-13, IL-5, and IL-22, was maintained or reduced upon exposure to G. lamblia. Goup 3 ILC (ILC3) was found to be dominant amongst the ILCs, and increased significantly upon co-cultivation with G. lamblia trophozoites. Oral inoculation of G. lamblia trophozoites into mice resulted in their presence in the small intestine, of which, the highest number of parasites was detected at the 5 days-post infection. Increased ILC3 was observed amongst the ILC population at the 5 days-post infection. These findings indicate that ILC3 from the lamina propria secretes IL-17 in response to G. lamblia, leading to the intestinal pathology observed in giardiasis.

Effects of some natural products from fungal and herbal sources on Giardia lamblia in vivo.

Giardia lamblia (G. lamblia) is the most widely known protozoan parasite that causes human gastrointestinal infection worldwide. Some natural compounds exhibited pivotal effects against different infectious diseases. In this research, the antigiardial activity and cytotoxicity of fungal chitosan, nano-chitosan, Rhamnus cathartica (R. cathartica) and emodin were evaluated in Balb/c mice. Genotyping of G. lamblia was assessed by PCR-RFLP technique. Different concentrations of mentioned compounds were used to check their antigiardial and cytotoxicity effects on human intestinal epithelial cells (HT-29) after 24, 48 and 72 h. The G. lamblia strain used in the current work was genotyped and revealed as an AII assemblage. All the concentration showed acceptable activity against G. lamblia cysts and trophozoites in comparison to the negative and positive controls (furazolidone and metronidazole) in vitro (P 0.05). The maximum mortality rate (100%) was achieved at 100 and 50 µg kg-1 concentrations after 48 and 72 h of exposure time, respectively. Our results provide significant information about the new antigiardial agent and proposed the nano-chitosan and emodin for the development of new drugs against G. lamblia in the future.

Effect of <i>Commiphora molmol</i> (Myrrh) Extract on Mice Infected by <i>Giardia lamblia</i>

Objective: To investigate the efficacy of (Commiphora molmol(Myrrh)) extract as alternative treatment in hamsters against giardiasis. This study was conducted to evaluate the effect of the new compound (Commiphora molmol(Myrrh)), as agent a natural product extracted from the roots of Zingiber officinal, on Giardia lamblia infection as anti-protozoal and to study the parasitological and Histopathological impact of this treatment on the duodenal mucosa of infected hamsters. Fifty hamsters were divided into five groups: Group (A): normal control. Group (B): Giardia lamblia infected and untreated hamsters served as control. Group (C): infected with Giardia lamblia and treated with metronidazole in dose (120 μg/kg body weight twice daily for 7 successive days). Group (D) Giardia lamblia infected and orally treated with Myrrh (500 mg/Kg for 1 week). Group (E): Giardia lamblia infected and orally treated with combination 1/3 dose of (120 μg/kg body weight) metronidazole and Myrrh (250 mg/Kg) for 1 week). After 2 weeks of the treatment, hamsters were sacrificed. The highest percentages of reduction in the number of Giardia lamblia cysts and trophozoites were in the group receiving combined metronidazole and myrrh. Histopathological examination revealed complete healing of intestinal mucosa after the combined treatment, while partial healing of the lining epithelium of the intestine was noticed after metronidazole and either myrrh plant treatment.

Roles of end-binding 1 protein and gamma-tubulin small complex in cytokinesis and flagella formation of Giardia lamblia.

Giardia lamblia is a unicellular organism with two nuclei, a median body, eight flagella, and an adhesive disk. γ‐Tubulin is a microtubule (MT)‐nucleating protein that functions in the γ‐tubulin small complex (γ‐TuSC) in budding yeast. In this study, G. lamblia γ‐tubulin (Glγ‐tubulin) was found to bind to another MT‐binding protein, namely G. lamblia end‐binding protein 1 (GlEB1), via both in vivo and in vitro assays. Hemagglutinin (HA)‐tagged Glγ‐tubulin localized to the basal bodies, axonemes, and median bodies of G. lamblia trophozoites. The knockdown of Glγ‐tubulin expression using an anti‐Glγ‐tubulin morpholino resulted in a decreased growth rate and an increased failed cytokinesis cells of Giardia. The formation of median bodies was affected, and the central pair of MTs in flagella was frequently missing in the Giardia treated with an anti‐Glγ‐tubulin morpholino. G. lamblia γ‐tubulin complex protein 2 (GlGCP2) and GlGCP3, which are putative components of γ‐TuSC, were co‐immunoprecipitated with HA‐tagged Glγ‐tubulin in Giardia extracts. The knockdown of GlGCP2 and GlGCP3 expression also resulted in decreased formation of both the median body and flagella MTs. Knockdown of Glγ‐tubulin, GlGCP2, and GlGCP3 expression affected localization of GlEB1 in G. lamblia. In addition, decreased level of GlEB1 caused reduced formation of median body and the central pair of flagella MTs. These results indicated that Glγ‐tubulin plays a role in MT nucleation for median body formation and flagella biogenesis as a component of Glγ‐TuSC in Giardia and GlEB1 may be involved in this process.

Seeing Spots: Eosinophilic Abscess as an Endoscopic Marker of Giardiasis

Introduction:Giardia lamblia is recognized as the most common protozoan found in the gastrointestinal tract, with the prevalence up to 60% in developing countries. Though typical symptoms may include diarrhea, abdominal discomfort, nausea, and dyspepsia, these are certainly not ubiquitous. A large retrospective review delineated diarrhea in only 29% of patients and abdominal pain in 71%. Gross upper endoscopic features of Giardiasis are nonspecific, including duodenal ulcers and duodenitis, and may be unremarkable in 75% of cases. Colonoscopic features have rarely been reported. To our knowledge, this case represents the first documentation of eosinophilic microabscesses visualized on colonoscopic examination in association with Giardia lamblia. CASE: A 49-year-old Ethiopian man was evaluated for episodic melena over 6 months. He denied abdominal pain, weight loss, fevers, alcohol or NSAID use. Laboratory testing revealed a hemoglobin of 14.3 g/dL, thrombocytopenia to 83 K/uL and peripheral eosinophilia of 11.1%. On upper endoscopy, a normal esophagus and stomach were visualized, though within the duodenal bulb, edema, inflammation, and an apthous ulcer were identified. Biopsies from the stomach and duodenum noted varied degrees of eosinophilic infiltration in the lamina propria, most prominently in the duodenal bulb, without suggestion of Helicobacter pylori. Colonoscopy revealed multiple subcentimeter white mucosal plaques within the cecum with mild surrounding erythema, as well as 3 small “polyps”. Biopsies from these cecal lesions showed polypoid colonic mucosa with marked patchy eosinophilic infiltration in the lamina propria. Both trichrome staining on duodenal aspirate and stool microscopy revealed moderate Giardia lamblia cysts and trophozoites. The patient was treated with oral metronidazole with resolution of symptoms. DISCUSSION: Screening for Giardia with stool microscopy or stool antigen detection by ELISA can be misguided by false negatives due to irregular parasite shedding. Giardia cysts or trophozoites may be identified in duodenal aspirate or on small bowel biopsy. Visualization of similar mucosal and submucosal white plaques or exudates have been reported in association with other hypereosinophilic disorders such as Eosinophilic Esophagitis. Given our case, visualization of these lesions on colonoscopy may prompt consideration of biopsy and analysis of stool to evaluate for parasitic infections such as Giardia lamblia.1915_A Figure 1. Duodenal Bulb endoscopic findings of edema, erythema, erosions, and superficial ulceration.1915_B Figure 2. Multiple sub-centimeter white mucosal plaques seen in the cecum, and identified throughout the colon.1915_C Figure 3. Cecal biopsy showing polypoid colonic mucosa with marked patchy eosinophilic infiltration in the lamina propria.

Mouse macrophages capture and kill Giardia lamblia by means of releasing extracellular trap

Giardia lamblia is one of the most prevalent parasites residing in the duodenum of human and many other mammals throughout the world which is transmitted via ingested cysts through contaminated food or water. The severity of disease may depend on multiple parasite and host factors. Commonly, children and immunologically compromised persons like AIDS patient exhibit severe diarrhea, malabsorption and weight loss, however, there are also some infected people who are asymptomatic or only exhibit mild clinical symptoms and can shed the Giardia cysts in the environment. Although many studies have indicated that the innate immune system is important for Giardia defense, however, whether the innate immune responses such extracellular traps (ETs) could be induced by G. lamblia is still unclear. In recent years, macrophage extracellular traps (METs) have been described as an effective defense mechanism against invading microorganisms. In the present study, the formation of METs triggered by G. lamblia trophozoites was investigated. The formation of METs induced by G. lamblia trophozoites of mouse macrophage was observed with Scanning Electron Microscopy (SEM). The main components DNA, H3 histone and MPO were confirmed by Sytox orange staining, DNase1 digestion, immunofluorescence staining and fluorescence confocal microscopy. Inhibitor assays suggested that G. lamblia trophozoites triggered METs formation through ERK1/2 and p38 MAPK signal pathways and was Store-operated Ca2+ entry (SOCE) dependent. In addition, the process of METs formation triggered by G. lamblia trophozoites was also time and dose-dependent. Furthermore, the production of Reactive Oxygen Species (ROS) in macrophages stimulated with G. lamblia trophozoites significantly increased whereas no significant changes were observed about LDH activity.

1H HR-MAS NMR spectroscopy to study the metabolome of the protozoan parasite Giardia lamblia

Knowledge of the metabolic profile and exchange processes in the protozoan parasite Giardia lamblia is of importance for a better understanding of the biochemical processes and for the development of drugs to control diseases caused by G. lamblia. In the current paper, 1H High Resolution Magic Angle Spinning (HR-MAS) NMR spectroscopy was directly applied to G. lamblia trophozoite suspensions to analyze the detectable small metabolites with a minimum of intervention. Thirty-one components were identified with main contributions from amino acids such as alanine and ornithine. The reproducibility, variability, and stability of the metabolites were investigated. Citrulline was found to be formed as an intermediate and citrulline levels depended on the stage of cell growth. Glucose-1-phosphate was found to be formed in relatively high amounts after cell harvesting if enzymes were not inactivated. In addition, the metabolic footprint of Giardia trophozoites, i.e. changes in the culture medium induced by G. lamblia, was investigated by liquid state NMR spectroscopy of culture media before and after inoculation. A quantitative comparison of the NMR spectra revealed component changes in the culture media during growth. The results suggested that not glucose but rather arginine serves as main energy supply. Biochemical functions of intracellular components and their metabolic exchange with the culture medium are discussed. The results provide an important basis for the design of HR-MAS NMR based metabolomic studies of G. lamblia in particular and any protozoan parasite samples in general.

Chemical analysis and giardicidal effectiveness of the aqueous extract of Cymbopogon citratus Stapf.

CcAE (25, 50, 100, 200, 400, and 500μg/ml) was in vitro incubated with G. lamblia trophozoites in comparison with metronidazole (MTZ 10 and 25μg/ml). Growth inhibition was evaluated after 3, 24, and 48h of drug exposure. Infected groups of mice were orally treated for 7days with CcAE at 125, 250, and 500mg/kg/day/mouse, in comparison with a group treated with 15mg/kg/day/mouse MTZ for the same period. The total phenolic components (TPC), the total flavonoid components (TFC), the 2,2,diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and the high-performance liquid chromatography (HPLC) for quantitative and qualitative phenolic content were chemically estimated. After 24 and 48h of in vitro incubation, the estimated minimal inhibitory concentrations (MIC) were 500 and 400μg/ml, respectively, and the concentrations that induced 50% growth inhibition (IC50) were 93.8 and 60.4μg/ml, respectively (P < 0.001). Mice given 500mg/kg CcAE showed 100% stool clearance of G. lamblia stages, similar to MTZ-treated control group (P < 0.001). The TPC was 10.7 ± 0.2mg GAE/g and the TFC was 23.9 ± 0.3mg quercetin/g, and the estimated IC50 for DPPH free radical scavenging was 16.4 ± 0.1mg/ml. HPLC revealed the major phenolic components of CcAE to be carnosic acid, p-coumaric acid, cinnamiac acid, quercetin, rutin, and chlorogenic acid. In conclusion, CcAE is significantly effective against G. lamblia in vitro and in vivo, and has considerable phenolic and antioxidant properties.

Antigiardial Activity of Some Plant Extracts Used in Traditional Medicine in Sudan in Comparison with Metronidazole

Giardiasis is one of the common parasitic diarrhoea in humans especially in children worldwide. Many drugs are used for its treatment but there is evidence of drug resistance, insufficient efficacy and unpleasant side effects. Natural products are good candidates for discovering more effective anti-giardial compounds. The aim of this study was to investigate the in vitro antigiardial activity of ethanolic extracts of Solennostemma argel, Trigonella foenum graecum and Mentha x piperita in comparison with metronidazole. Giardia trophozoites were isolated from feacal samples. The ethanolic extracts of 3 plants with concentration of 5000 ppm were investigated together with metronidazole (positive control) at 0.3125 ppm against G. lamblia trophozoites. The extracts of 3 plants were incubated at 37°C for 24, 48, 72 and 96 h. Mortality of trophozoites was observed by 0.4% Trypan blue and a haemocytometer. Trigonella foenum graecum, Mentha x piperita and Solennostemma argel exhibited 98%, 92% and 65% mortality respectively within 96 h at concentration of 5000 ppm (5 mg/ml). This was compared to metronidazole which gave 100% inhibition at concentration of 0.3125 ppm at the same time. The ethanolic extracts of Trigonella foenum graecum, Solennostemma argel and Mentha x piperita had potent antigiardial activity. This will provide natural therapeutic treatment to giardiasis with minimal side effects and drug resistance. We recommend using these plants against Giardia lamblia in the in vivo and also to find fractions of the pharmacological effects of these plants.

Antigiardial Activity of Cupania dentata Bark and its Constituents

The MeOH extract of Cupania dentata bark (Sapindaceae) as well as its hexane, CH2Cl2, EtOAc, and BuOH fractions showed high activity against Giardia lamblia trophozoites (IC50 = 2.12-9.52 μg/mL). The phytochemical study of fractions resulted in the isolation of taraxerone (1), taraxerol (2), scopoletin (3), and two mixtures of steroidal compounds. Taraxerone was the metabolite with the highest giardicidal activity (IC50 = 11.33 μg/mL).

In vitro activity of some natural honeys against Entamoeba histolytica and Giardia lamblia trophozoites.

Considering the potentiality of honey in combating diseases, the present study was carried out aiming to assess the in vitro antiprotozoal activity of several honeys (Ziziphus spina-christi, Acacia nilotica, Acacia seyal, and Cucurbita maxima) against Entamoeba histolytica and Giardia lamblia by employing the sub-culture method. All the tested honeys inhibited the growth of trophozoites, and the level of inhibition varied according to the assayed concentrations and incubation times. Acacia seyal honey had completely stopped motility of E. histolytica trophozoites at a concentration ≤ 50 µg/ml after incubation for 72 h. Ziziphus spina-christi, Acacia seyal, and Acacia nilotica honeys had completely inhibited the growth of Giardia lamblia trophozoites at concentration ≤ 200 µg/ml after 72 h. These inhibitory activities were similar to that of Metronidazole™ which showed IC50 = 0.27. The mammalian cytotoxicity of these honeys against normal Vero cell line which determined by applying MTT method verified the nontoxicity of the examined honeys. Also the proximate composition of the samples indicated compliance with the natural honey standards. The findings of the study indicate the need for in vivo studies and further investigations to identify active principles with antiprotozoal activities from natural honeys.