In vitro efficacy of allicin on chicken Eimeria tenella sporozoites

Management and control of coccidiosis in poultry - A review

Poultry coccidiosis is an intestinal infection caused by an intracellular parasitic protozoan of the genus Eimeria. Coccidia-induced gastrointestinal inflammation results in large economic losses, hence finding methods to decrease its prevalence is critical for industry participants and academic researchers. It has been demonstrated that coccidiosis can be effectively controlled and managed by employing anticoccidial chemical compounds. However, as a result of their extensive use, anticoccidial drug resistance in Eimeria species has raised concerns. Phytochemical/herbal medicines (Artemisia annua, Bidens pilosa, and garlic) seem to be a promising strategy for preventing coccidiosis, in accordance with the "anticoccidial chemical-free" standards. The impact of herbal supplements on poultry coccidiosis is based on the reduction of oocyst output by preventing the proliferation and growth of Eimeria species in chicken gastrointestinal tissues and lowering intestinal permeability via increased epithelial turnover. This review provides a thorough up-to-date assessment of the state of the art and technologies in the prevention and treatment of coccidiosis in chickens, including the most used phytochemical medications, their mode of action, and the applicable legal framework in the European Union.

Opuntia Ficus-Indica Peel By-Product as a Natural Antioxidant Food Additive and Natural Anticoccidial Drug

The present study was carried out to valorize the Opuntia ficus-indica (OFI) by-products by extracting and identifying their biochemical compounds and evaluating their antioxidant potential by in vitro activities (DPPH radical and FRAP), as well as their capacity to stabilize margarine oxidation (rancimat test). In addition, their in vitro anticoccidial effect on the destruction of Eimeria oocysts isolated from naturally infected chickens was also targeted. Microwaves and response surface methodology tools were used to extract the maximum amount of phenolic compounds (42.05 ± 0.46 GAE mg/g DW of total phenolic compounds in 90 s at 400 watts). Moreover, the effect of extraction factors was also studied. Eight phenolic compounds, including isorhamnetin, dihydrokaempferol, and kaempferol-3-O-rutinoside, were identified. The findings confirmed that OFI peel extract has strong antioxidant activities (DPPH radical, ferric reducing power). The rancimat test shows that OFI peel extract improves margarine stability by 3.2 h. Moreover, it has a notable destruction rate of Eimeria oocysts (30.06 ± 0.51%, LC50: 60.53 ± 0.38 mg/mL). The present investigation offers promise for the reuse of food waste as natural margarine additives, protection of the environment, and substitution of anticoccidial synthetic treatments.

Investigating the effects of essential oils and pure botanical compounds against Eimeria tenella in vitro

Essential oils (EO) and natural bioactive compounds are well-known antibacterial and anti-inflammatory factors; however, little is known about their anticoccidial activity and mode of action. EO deriving from basil (BEO), garlic (GAR), oregano (OEO), thyme (TEO), and their main bioactive compounds were investigated for their anticoccidial proprieties and compared to salinomycin (SAL) and amprolium (AMP) in vitro. The invasion of Eimeria tenella sporozoites was studied on 2 cell models: Madin-Darby Bovine Kidney (MDBK) cells and primary chicken epithelial cells (cIEC). Invasion efficiency was evaluated at 2 and 24 h postinfection (hpi) with counts of extracellular sporozoites and by detection of intracellular E. tenella DNA by PCR. Results show that at both timepoints, the EO were most effective in preventing the invasion of E. tenella with an average reduction of invasion at 24 hpi by 36% in cIEC and 55% in MDBK. The study also examined cytokine gene expression in cIEC at 24 hpi and found that AMP, BEO, OEO, TEO, carvacrol (CAR), and thymol (THY) significantly reduced interleukin (IL)8 expression, with CAR also reducing expression of IL1β and IL6 compared to the infected control. In addition, this work investigated the morphology of E. tenella sporozoites treated with anticoccidial drugs and EO using a scanning electron microscope. All the treatments induced morphological anomalies, characterized by a reduction of area, perimeter and length of sporozoites. SAL had a significant impact on altering sporozoite shape only at 24 h, whereas CAR and THY significantly compromised the morphology already at 2 hpi, compared to the untreated control. OEO and GAR showed the most significant alterations among all the treatments. The findings of this study highlight the potential of EO as an alternative to traditional anticoccidial drugs in controlling E. tenella invasion and in modulating primary immune response.

The In Vitro Anticoccidial Activity of Some Herbal Extracts against Eimeria spp. Oocysts Isolated from Piglets

Coccidiosis in pigs seldom results in important economic losses. However, it can influence growth rates in weaners and it is an important hygiene indicator in swine farms. Certain herbs, along with their extracts, have been used over the course of history in traditional medicine. The aim of this study was to evaluate the in vitro anticoccidial effects of Allium sativum L. (garlic), Artemisia absinthium L. (wormwood), Coriandrum sativum L. (coriander), Cucurbita pepo L. (pumpkin), Satureja hortensis L. (summer savory), and Calendula officinalis L. (marigold) against Eimeria suis and Eimeria debliecki oocysts. The stock solution of oocysts (58% E. suis + 42% E. debliecki) was incubated for three days, before adding the tested solutions. The unsporulated Eimeria spp. oocysts were then placed in a 3 mL well plate and incubated for 96 h at 27 °C, in a suspension containing serial dilutions of alcoholic plant extracts (5%, 2.5%, 1.25%, 0.625%, and 0.312%). The percentage of sporulated and destroyed oocysts was recorded every 24 h for 96 h. All extracts had a good in vitro anticoccidial effect against oocysts of Eimeria spp. compared with the control groups. Oocyst sporulation was significantly (p = 0.05) inhibited by the 5% marigold extract (3.6% sporulated oocysts). The same extract had the highest lytic effect on oocysts (65.2% destroyed oocysts). Our results prove that the most effective alcoholic plant extract is the marigold extract, followed, in order of efficiency, by the wormwood, coriander, garlic, pumpkin, and summer savory extracts. This study represents a preliminary contribution for establishing a new generation of natural disinfectants aimed at destroying Eimeria oocysts in the context of swine contamination.

Comparative Effect of Allicin and Alcoholic Garlic Extract on the Morphology and Infectivity of Eimeria tenella Oocysts in Chickens

Avian coccidiosis remains one of the major parasitic diseases that threaten the global poultry industry. Since prevention is superior to treatment, this study focuses on eliminating the infection outside the host. To determine their effect on the viability of Eimeria tenella oocysts in vitro, allicin and alcoholic garlic extract, which are natural, less toxic, and inexpensive products, were compared to KOH 5% (chemical disinfectant) using an in vitro culture system. Three concentrations of allicin (45, 90, and 180 mg/mL) and alcoholic garlic extract (90, 180, and 360 mg/mL, were used. Subsequently, destructive and sporulation-inhibiting effects on Eimeria oocysts were detected using light and electron microscopy. Young chickens were infected with treated sporulated oocysts to determine their effect on infectivity. After 7 days pi, the percentage of excreted oocysts (oocyst shedding) was determined, and the chickens were slaughtered for histopathological examination of the cecal tissues. Under an electron microscope, allicin at a concentration of 180 mg/mL and alcoholic garlic extract at a concentration of 360 mg/mL demonstrate a high oocysticidal activity with severe destruction of the oocyst wall and the appearance of pores. In addition, both concentrations directly affected the infectivity of sporulated oocysts by reducing the shedding of oocysts and the pathological lesions of infected young chickens. We concluded that the ability of Allicin and alcoholic garlic extract to eliminate Eimeria oocysts makes them superior to chemical disinfectants as a disinfectant.

Ultrastructural tegumental changes of Trichinella spiralis adult and larval stages after in vitro exposure to Allium sativum

Albendazole (ALB) is the most used therapeutic drug for trichinellosis treatment, but it has many drawbacks. Hence, the search for alternative natural compounds is a goal for researchers. The present work aimed to test the in vitro anthelmintic effect of Tomex (Allium sativum) against adult and muscular larva of Trichinella spiralis (T. spiralis). We incubated adult forms and muscular larvae of T. spiralis with Tomex at concentrations 10, 50, and 100 μg/mL to evaluate the changes that happened on the cuticle using a scanning electron microscopy (SEM). Although ALB was very effective, Tomex also affected motility and the tegumental structure of T. spiralis, which was in proportion to its concentration and incubation time, as Tomex started the mortality of muscular larvae and adult stages after 4 h at 50 μg/mL, and after 6 h at10 μg/mL. A 50% mortality rate of muscular larvae was recorded after 6 h at 100 μg/mL. However, a 50% mortality rate was recorded after 12 h at 10 μg/mL for the adult stage. Adult worms and muscular larvae of T. spiralis incubated with 100 μg/mL of Tomex displayed loss of normal annulations and creases of the cuticle, multiple vesicles, widening of longitudinal furrow space, and multiple minor loss blebs. Our results suggested that Tomex can be a therapeutic agent against adults and larvae stages of T. spiralis.

Medicinal Plants as an Alternative to Control Poultry Parasitic Diseases

Parasitic infections are a major public health concern affecting millions of people universally. This review elaborates on the potential impacts of plants and their bioactive components that have been widely used in the cure of several parasitic infections of poultry. The medicinal importance of natural herbs depends upon their bioactive ingredients, which are originated from crude plants, consequently leading to the specific action on the body. Due to the limited availability of effective drugs and high cost, the development of drug resistance in several harmful parasites and microbes leads to huge economic losses in the poultry industry. This will impose the development of innovative sources for drugs to overwhelm the therapeutic failure. Moreover, the environment-friendly feed additives which can be applied as a substitute to antibiotic growth promoters (AGP) for broilers were proven. The application of natural products with therapeutic characteristics is an ancient practice that is appropriately gaining more acceptance. Globally, it is assessed that some 20,000 species of higher plants are used medicinally, although traditional medicine has a scarcity of knowledge on its efficiency and wellbeing. This review explores the usage of medicinal herbs for parasitic infections, emphasizing the recent knowledge available while detecting the research gaps which may be explored to find the usage of herbal medicines for parasitic infections in poultry. In conclusion, herbal medicines are the effective source of prime components for drug detection and the formation of phytopharmaceuticals in the control of devastating parasitic infections. There is a prerequisite to applying the traditional medicine information in clinical applications via value addition.

Phytochemical control of poultry coccidiosis: a review

Avian coccidiosis is a major parasitic disorder in chickens resulting from the intracellular apicomplexan protozoa Eimeria that target the intestinal tract leading to a devastating disease. Eimeria life cycle is complex and consists of intra- and extracellular stages inducing a potent inflammatory response that results in tissue damage associated with oxidative stress and lipid peroxidation, diarrheal hemorrhage, poor growth, increased susceptibility to other disease agents, and in severe cases, mortality. Various anticoccidial drugs and vaccines have been used to prevent and control this disorder; however, many drawbacks have been reported. Drug residues concerning the consumers have directed research toward natural, safe, and effective alternative compounds. Phytochemical/herbal medicine is one of these natural alternatives to anticoccidial drugs, which is considered an attractive way to combat coccidiosis in compliance with the "anticoccidial chemical-free" regulations. The anticoccidial properties of several natural herbal products (or their extracts) have been reported. The effect of herbal additives on avian coccidiosis is based on diminishing the oocyst output through inhibition or impairment of the invasion, replication, and development of Eimeria species in the gut tissues of chickens; lowering oocyst counts due to the presence of phenolic compounds in herbal extracts which reacts with cytoplasmic membranes causing coccidial cell death; ameliorating the degree of intestinal lipid peroxidation; facilitating the repair of epithelial injuries; and decreasing the intestinal permeability induced by Eimeria species through the upregulation of epithelial turnover. This current review highlights the anticoccidial activity of several herbal products, and their other beneficial effects.

Review of herbal medicine works in the avian species

Poultry meat consumption is increasing worldwide but the overuse of antimicrobials for prevention and treatment of diseases has increased antimicrobial resistance (AMR), triggering a major public health issue. To restrict AMR emergence, the government supports the optimization of natural products that are safe and easy to obtain with minimal side effects on poultry, humans, and the environment. Various studies have explored the potential of herbs in animal health for their antiviral, antibacterial, antifungal, antiparasitic, immunomodulatory, antioxidant, and body weight gain properties. Therefore, this study reviewed plants with potential application in avian species by summarizing and discussing the mechanisms and prophylactic/therapeutic potential of these compounds and their plant origin extracts.

In Vitro Assessment of Anticoccidials: Methods and Molecules

Simple Summary

Coccidiosis is a major problem in poultry production, leading to significant economic losses. Due to the outbreak of resistance to the available treatments, research is focusing on finding new molecules that work against the pathogen. Botanical compounds represent promising alternatives, but reliable in vitro tests are needed for their screening and to understand their mechanism of action. Research in vitro involves studies on the environmental phase of the parasite and studies on the endogenous development, which occurs inside the host cells and that requires cell cultures or in ovo models to be studied. This review aims to summarize the protocols that have been successfully applied so far, as well as to suggest potential cues to improve research on this field. Moreover, as the surge of botanicals as anticoccidial molecules is on the rise, the intent is to provide an overview of the methods to assess their effectiveness in vitro in comparison with conventional drugs.

Abstract

Avian coccidiosis is a disease causing considerable economic losses in the poultry industry. It is caused by Eimeria spp., protozoan parasites characterized by an exogenous–endogenous lifecycle. In vitro research on these pathogens is very complicated and lacks standardization. This review provides a description of the main in vitro protocols so far assessed focusing on the exogenous phase, with oocyst viability and sporulation assays, and on the endogenous phase, with invasion and developmental assays in cell cultures and in ovo. An overview of these in vitro applications to screen both old and new remedies and to understand the relative mode of action is also discussed.

The Effects of Selenium-Enriched Probiotics on Growth Performance, Oocysts Shedding, Intestinal Cecal Lesion Scores, Antioxidant Capacity, and mRNA Gene Expression in Chickens Infected with Eimeria tenella

This study was carried out to investigate the effects of selenium-enriched probiotics (SP) supplementation on growth performance, oocysts shedding, intestinal lesions and antioxidant capacities, and mRNA gene expression of local Chinese yellow male chickens infected with Eimeria tenella. One-day-old 270 chickens were randomly assigned into five groups, each consisting of three replicates with 18 chickens per replicate. Chickens in the negative and positive controls (NC, PC, respectively) received basal diets only (0.11 mg Se/kg), whereas the other groups were supplied basal diets with probiotics and designated as (P, 0.11 mg Se/kg), sodium selenite (SS, 0.41 mg Se/kg), and (SP, 0.41 mg Se/kg) groups. At 21 days of age, except the NC group, all other groups were infected by oral gavage with 1.5 × 10⁴ sporulated E. tenella oocysts per chicken. Three chickens were randomly selected from each group for serum, liver, and cecal specimen collection. The results showed that P, SS, and SP had significant increase weight gain and feed intake. Additionally, these groups showed higher activities of serum superoxide dismutase (SOD) and glutathione peroxidase-1 (GPx1) compared to the PC group, whereas feed conversion ratio (FCR), serum catalase (CAT) activity, and malondialdehyde (MDA) content remained lower. Moreover, P, SS, and SP groups had lower oocyst shedding and cecal lesion scores. Significant upregulation of the glutathione peroxidase-1 (GPx1), glutathione peroxidase-4 (GPx4), Selenium W (SelW), and interferon gamma (IFN-γ) mRNA expression were detected in the SP group, which was then followed by SS when compared to the P group, whereas mRNA expression down-regulated in the PC group compared to NC, P, SS, and SP. In the NC and P groups, there were no significant differences in mRNA expression, except that IFN-γ mRNA level upregulated in P. We concluded that selenium-enriched probiotic supplementation has profound effects in enhancing the growth performance, antioxidant capacities, mRNA gene expression, reduced of oocysts shedding, and the cecal lesion scores of chickens and do provide protection against E. tenella.

The Growth of Eimeria tenella: Characterization and Application of Quantitative Methods to Assess Sporozoite Invasion and Endogenous Development in Cell Culture

In vitro development of the complete life cycle of Eimeria species has been achieved in primary cultures of avian epithelial cells with low efficiency. The use of immortalized cell lines simplifies procedures but only allows partial development through one round of parasite invasion and intracellular replication. We have assessed the suitability of Madin-Darby Bovine Kidney (MDBK) cells to support qualitative and quantitative studies on sporozoite invasion and intracellular development of Eimeria tenella. Analysis of parasite ultrastructure by transmission electron microscopy and serial block face-scanning electron microscopy proved the suitability of the system to generate good quality schizonts and first-generation merozoites. Parasite protein expression profiles elucidated by mass spectrometry corroborated previous findings occurring during the development of the parasite such as the presence of alternative types of surface antigen at different stages and increased abundance of proteins from secretory organelles during invasion and endogenous development. Quantitative PCR (qPCR) allowed the tracking of development by detecting DNA division, whereas reverse transcription qPCR of sporozoite- and merozoite-specific genes could detect early changes before cell division and after merozoite formation, respectively. These results correlated with the analysis of development using ImageJ semi-automated image analysis of fluorescent parasites, demonstrating the suitability and reproducibility of the MDBK culture system. This systems also allowed the evaluation of the effects on invasion and development when sporozoites were pre-incubated with anticoccidial drugs, showing similar effects to those reported before. We have described through this study a series of methods and assays for the further application of this in vitro culture model to more complex studies of Eimeria including basic research on parasite cell biology and host-parasite interactions and for screening anticoccidial drugs.

In vitro anticoccidial activity of thymol, carvacrol, and saponins

The anticoccidial activity of thymol, carvacrol, and saponins was assessed in an in vitro model of coccidiosis. Eimeria spp. sporozoites were collected from field samples, characterized, and used for 2 different invasion assays on Madin-Darby Bovine Kidney cells (MDBK). The cells were challenged with 5 × 10⁴ sporozoites without (control) or with various treatments: saponins (10 ppm), thymol, and carvacrol (7 ppm each) or a combination of saponins, thymol, and carvacrol at 2 doses; MIX 1 (saponins 5 ppm, thymol 3.5 ppm, and carvacrol 3.5 ppm) and MIX 2 (saponins 10 ppm, thymol 7 ppm, and carvacrol 7 ppm). The treated cells were incubated at 37°C for 24 h (invasion assay 1) and for 2, 24, and 48 h (invasion assay 2). The efficiency of invasion was determined by counting the sporozoites left in the supernatant that were not able to invade the cells, whereas intracellular Eimeria DNA was detected by qPCR to confirm the data. Data were analyzed with ANOVA, and differences were considered significant when P value was ≤0.05. Data from invasion assay 1 showed that the thymol and carvacrol-containing blends significantly reduced invasion, especially in combination with saponins at the highest dose. Saponins alone did not have a strong inhibiting activity but acted synergistically with the other molecules. Interestingly, in invasion assay 2, it was found that the effect of the highest dose of the blend of saponins, thymol, and carvacrol was already visible at 2 h postinfection, whereas the other treatments were significantly successful at 24 h postinfection. The invasion assay protocol was designed to screen molecules in vitro starting from field fecal samples, and it can represent a potential tool in Eimeria research. Moreover, this study shows that invasion in MDBK cells by Eimeria sporozoites is inhibited in presence of thymol, carvacrol, and saponins, thus highlighting the anticoccidial potential of these compounds.

In Vitro Anticoccidial Activity of Olive Pulp (Olea europaea L. var. Chemlal) Extract Against Eimeria Oocysts in Broiler Chickens

AIM

The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally.

MATERIALS AND METHODS

The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography-mass spectrometry with electrospray ionisation (HPLC-ESI-MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm.

RESULTS

Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R² = 0.959. From this in vitro experiment, it can be concluded that the OP extract possesses an anti-Eimeria spp activity.

CONCLUSION

To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens.

Eimeria tenella oocysts attenuated by low energy electron irradiation (LEEI) induce protection against challenge infection in chickens

In vitro and in vivo studies were performed to assess whether Eimeria tenella (E. tenella) oocysts, exposed to low energy electron irradiation (LEEI), might be considered potential vaccine candidates against cecal coccidiosis. Sporulated oocysts were exposed to LEEI of 0.1 kGy to 10.0 kGy. Reproduction inhibition assays (RIA) were performed in MDBK cells to assess infectivity of sporozoites excysted from irradiated and non-irradiated oocysts. LEEI of 0.1 kGy or 0.5 kGy resulted in 73.2% and 86.5% inhibition of in vitro reproduction (%I_RIA), respectively. Groups of 12 one day old (D1) chicken were orally inoculated with Paracox®-8 (G1), 2.0 × 10³ non-irradiated oocysts (G2) or 1.0 × 10⁴ irradiated oocysts exposed to LEEI of 0.1 kGy (G3, G4) or 0.5 kGy (G5). Chicken of groups G1, G2, G4 and G5 were challenged 3 weeks later (D21) by a single inoculation of 7.5 × 10⁴ non-attenuated oocysts of the same strain while G3 remained unchallenged. All chickens were subject to necropsy 7 days after challenge (D28) to estimate lesion scores (LS) and oocyst index (OI). A positive control (PC, non-vaccinated, challenged) and a negative control (NC, non-vaccinated, non-challenged) were kept in parallel. Chicken of group G5 had similar weight gain as the Paracox®-8 group (G1) after challenge and higher weight gains as compared to the other vaccinated groups. Feed conversion ratio (FCR) did not differ between chickens inoculated with oocysts irradiated with 0.5 kGy (G5) and negative control (NC) before challenge (1.25-1.52). After challenge FCR was 1.99 (G5) to 2.23 (G4) in the vaccinated chicken compared to 1.76 in group NC. LS and OI were significantly lower in all vaccinated groups as compared to group PC. Progeny oocysts collected from the feces of chickens following vaccination with irradiated oocysts exhibited lower in vitro infectivity/reproduction in MDBK cells with %I_RIA of 89.7% and 82.4% for progeny of oocysts irradiated with 0.5 kGy and 0.1 kGy, respectively, suggesting hereditary attenuation by LEEI treatment. Seroconversion was demonstrated by ELISA before challenge (D21) in all vaccinated groups, however, chicken inoculated with irradiated oocysts displayed higher antibody levels than those inoculated with precocious oocysts (G1). In Western blot analysis chicken vaccinated with virulent (G2) or 0.1 kGy-irradiated E. tenella oocysts (G3, G4) showed more protein bands compared to G5 (0.5 kGy). We conclude that LEEI could be a promising technology for production of attenuated oocyst vaccines.

Activity of Thioallyl Compounds From Garlic Against Giardia duodenalis Trophozoites and in Experimental Giardiasis

Fresh aqueous extracts (AGEs) and several thioallyl compounds (TACs) from garlic have an important antimicrobial activity that likely involves their interaction with exposed thiol groups at single aminoacids or target proteins. Since these groups are present in Giardia duodenalis trophozoites, in this work we evaluated the anti-giardial activity of AGE and several garlic's TACs. In vitro susceptibility assays showed that AGE affected trophozoite viability initially by a mechanism impairing cell integrity and oxidoreductase activities while diesterase activities were abrogated at higher AGE concentrations. The giardicidal activities of seven TACs were related to the molecular descriptor HOMO (Highest Occupied Molecular Orbital) energy and with their capacity to modify the -SH groups exposed in giardial proteins. Interestingly, the activity of several cysteine proteases in trophozoite lysates was inhibited by representative TACs as well as the cytopathic effect of the virulence factor giardipain-1. Of these, allicin showed the highest anti-giardial activity, the lower HOMO value, the highest thiol-modifying activity and the greatest inhibition of cysteine proteases. Allicin had a cytolytic mechanism in trophozoites with subsequent impairment of diesterase and oxidoreductase activities in a similar way to AGE. In addition, by electron microscopy a marked destruction of plasma membrane and endomembranes was observed in allicin-treated trophozoites while cytoskeletal elements were not affected. In further flow cytometry analyses pro-apoptotic effects of allicin concomitant to partial cell cycle arrest at G2 phase with the absence of oxidative stress were observed. In experimental infections of gerbils, the intragastric administration of AGE or allicin decreased parasite numbers and eliminated trophozoites in experimentally infected animals, respectively. These data suggest a potential use of TACs from garlic against G. duodenalis and in the treatment of giardiasis along with their additional benefits in the host's health.

In vitro activity of natural and chemical products on sporulation of Eimeria species oocysts of chickens

This study was designed to investigate the ability of two herbal extracts and different chemical substances to inhibit or disrupt sporulation of Eimeria species oocysts of the chickens. The two herbal extracts were Allium sativum (garlic) and Moringa olifiera while the chemical substances included commercial disinfectants and diclazuril. Field isolates of Eimeria oocysts were propagated in chickens to obtain a continuous source of oocysts. The collected unsporulated oocysts (10⁵oocysts/5 ml) were dispensed into 5 cm Petri dish. Three replicates were used for each treatment. The treated oocysts were incubated for 48 h at 25-29 °C and 80% relative humidity. The results showed that herbal extracts, the commercial recommended dose of Dettol, TH4, Phenol, Virkon^®S, and Diclazuril 20% have no effect on the sporulation. While Sodium hypochlorite showed a significant degree of sporulation inhibition reached to 49.67%. Moreover, 70% ethanol, and 10% formalin showed 100% sporulation inhibition. It was concluded that 70% ethanol and 10% formalin are the most effective methods to inhibit Eimeria species sporulation.

Effect of Calotropis procera (madar) and amprolium supplementation on parasitological parameters of broilers during mixed Eimeria species infection

AIM

An experiment was conducted on day old 168 broiler chicks to study the effect of 0.4% as well as 0.2% Calotropis procera (madar) leaf powder and 0.0125% amprolium supplementation on parasitological parameters of broilers during mixed Eimeria species infection.

MATERIALS AND METHODS

Chicks were randomly divided into seven groups (I-VII) each with two replicates of 12 chicks. On 15^th day of experiment, broilers of Group II, IV, VI, and VII were infected with 50,000 sporulated oocysts of mixed Eimeria species. To evaluate the anticoccidial effect of different feed supplements percent fecal score, percent survival, percent weight gain, performance index (PI), average oocyst production, and percent reduction in oocyst production were calculated.

RESULTS

It was observed that amprolium supplementation had maximum anticoccidial effect as it gave the best efficacy in terms of all parameters, whereas supplementation of 0.4% madar leaf powder showed nonsignificant difference with amprolium for some parameters such as percent survival, percent weight gain, and PI.

CONCLUSION

It can be concluded that madar (C. procera) leaf powder and amprolium had comparable activity against coccidiosis. Hence, madar leaf powder may be used for the prevention and control of mixed Eimeria spp. infection prevalent in field conditions.

Anticoccidial efficacy testing: In vitro Eimeria tenella assays as replacement for animal experiments

SCOPE

Availability of an accurate in vitro assay is a crucial demand to determine sensitivity of Eimeria spp. field strains toward anticoccidials routinely. In this study we tested in vitro models of Eimeria tenella using various polyether ionophores (monensin, salinomycin, maduramicin, and lasalocid) and toltrazuril. Minimum inhibitory concentrations (MIC₉₅, MIC_50/95) for the tested anticoccidials were defined based on a susceptible reference (Houghton strain), Ref-1. In vitro sporozoite invasion inhibition assay (SIA) and reproduction inhibition assay (RIA) were applied on sensitive laboratory (Ref-1 and Ref-2) and field (FS-1, FS-2, and FS-3) strains to calculate percent of inhibition under exposure of these strains to the various anticoccidials (%I_SIA and%I_RIA, respectively). The in vitro data were related to oocyst excretion, lesion scores, performance, and global resistance indices (GI) assessed in experimentally infected chickens.

RESULTS

Polyether ionophores applied in the RIA were highly effective at MIC₉₅ against Ref-1 and Ref-2 (%I_RIA≥95%). In contrast, all tested field strains displayed reduced to low efficacy (%I_RIA<95%).%I_RIA values significantly correlated with oocyst excretion determined in the animal model (p<0.01) for polyether ionophores. However, this relationship could not be demonstrated for toltrazuril due to unexpected lack of in vitro sensitivity in Ref-2 (%I_RIA=56.1%). In infected chickens, toltrazuril was generally effective (GI>89%) against all strains used in this study. However, adjusted GI (GI_adj) for toltrazuril-treated groups exhibited differences between reference and field strains which might indicate varying sensitivity.

CONCLUSION

RIA is a suitable in vitro tool to detect sensitivity of E. tenella towards polyether ionophores, and may thus help to reduce, replace, or refine use of animal experimentation for in vivo sensitivity assays.

Herbal Remedies for Coccidiosis Control: A Review of Plants, Compounds, and Anticoccidial Actions

Coccidiosis is the bane of the poultry industry causing considerable economic loss. Eimeria species are known as protozoan parasites to cause morbidity and death in poultry. In addition to anticoccidial chemicals and vaccines, natural products are emerging as an alternative and complementary way to control avian coccidiosis. In this review, we update recent advances in the use of anticoccidial phytoextracts and phytocompounds, which cover 32 plants and 40 phytocompounds, following a database search in PubMed, Web of Science, and Google Scholar. Four plant products commercially available for coccidiosis are included and discussed. We also highlight the chemical and biological properties of the plants and compounds as related to coccidiosis control. Emphasis is placed on the modes of action of the anticoccidial plants and compounds such as interference with the life cycle of Eimeria, regulation of host immunity to Eimeria, growth regulation of gut bacteria, and/or multiple mechanisms. Biological actions, mechanisms, and prophylactic/therapeutic potential of the compounds and extracts of plant origin in coccidiosis are summarized and discussed.