In vitro inhibition of Eimeria tenella invasion of epithelial cells by phytochemicals

Synthesis and evaluation of febrifugine derivatives as anticoccidial agents

A series of new febrifugine derivatives with a 4(3H)-quinazolinone scaffold were synthesized and evaluated for their anticoccidial activity both in vitro and in vivo. The targets' in vitro activity against Eimeria tenella was studied using quantitative real-time reverse transcription polymerase chain reaction and Madin-Darby bovine kidney cells. Most of these compounds demonstrated anticoccidial efficacy, with inhibition ratios ranging from 3.3% to 85.7%. Specifically, compounds 33 and 34 showed significant inhibitory effects on the proliferation of E. tenella and exhibited lower cytotoxicity compared to febrifugine. The IC50 values of compounds 33 and 34 were 3.48 and 1.79 μM, respectively, while the CC50 values were >100 μM for both compounds. Furthermore, in a study involving 14-day-old chickens infected with 5 × 104 sporulated oocysts, treatment with five selected compounds (22, 24, 28, 33, and 34), which exhibited in vitro inhibition rate of over 50% at 100 μM, at a dose of 40 mg/kg in daily feed for 8 consecutive days showed that compound 34 possessed moderate in vivo activity against coccidiosis, with an anticoccidial index of 164. Structure-activity relationship studies suggested that spirocyclic piperidine may be a preferable substructure to maintain high effectiveness in inhibiting Eimeria spp., when the side chain 1-(3-hydroxypiperidin-2-yl)propan-2-one was replaced.

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.

In Vitro Antioxidant, Antimicrobial, Anticoccidial, and Anti-Inflammatory Study of Essential Oils of Oregano, Thyme, and Sage from Epirus, Greece

Origanum vulgare subsp. hirtum, Thymus vulgaris, and Salvia fructicosa are aromatic plants commonly found in Mediterranean countries and are traditionally used in Greece as a remedy for humans, since they are well known as potent antibacterial, antioxidant, and anti-inflammatory agents. Essential oils (EOs) derived from plants cultivated in the mountainous region of Epirus, Greece, were investigated for their inhibitory activity against key microorganisms with relevance to avian health, while also assessing their antioxidant and anti-inflammatory activity. The total phenolic content (TPC) of the EOs was estimated according to the Folin−Ciocalteu method, while the antioxidant capacity was tested through the EOs’ ability to scavenge free radicals by means of the DPPH, ABTS, and FRAP assays. Antibacterial and anti-inflammatory effects were examined by the agar disc diffusion method and the lipoxygenase (LOX) inhibition test, respectively. Furthermore, the EOs’ ability to inhibit the invasion of sporozoites of Eimeria tenella (Wisconsin strain) along with any toxic effects were assayed in Madin−Darby bovine kidney (MDBK) cells. The antioxidant activity of the EOs was observed in descending order: oregano > thyme > sage. The antimicrobial effects of thyme and oregano were equivalent and higher than that of sage, while the anti-inflammatory effect of thyme was higher compared to both sage and oregano. The intracellular invasion of sporozoites was evaluated by the detection of E. tenella DNA by qPCR from cell monolayers harvested at 2 and 24 h post-infection. Parasite invasion was inhibited by the addition of oregano essential oil at the concentration of 100 μg/mL by 83% or 93% after 2 or 24 h, respectively, and was higher compared to the addition of thyme and sage, which had similar effects, but at a less intensive level. The cytotoxic assessment of all three essential oils revealed that they had no effect on MDBK cells compared to dimethyl sulfoxide (DMSO), used as the control substance. The supplementation of oregano, thyme, and sage essential oils had a potent antioxidant, anti-inflammatory, antimicrobial, and anticoccidial in vitro effect that is comparable to synthetic substances or approved drugs, justifying the need for further evaluation by in vivo studies in broilers reared in the absence of antimicrobial and anticoccidial drugs or synthetic antioxidant and/or anti-inflammatory compounds.

In Vitro Antiparasitic Activity of Propyl-Propane-Thiosulfinate (PTS) and Propyl-Propane-Thiosulfonate (PTSO) from Allium cepa against Eimeria acervulina Sporozoites

Among the alternatives to control avian coccidiosis, alliaceous extracts stand out due to their functional properties. Despite this, most of the references are focused just on garlic. In this study, we analyze the in vitro effects of propyl-propane thiosulfinate (PTS) and propyl-propane thiosulfonate (PTSO), two organosulfur compounds from onion, on MDBK cells infected with sporozoites of Eimeria acervulina. To this aim, two different experiments were performed. In the first experiment, sporozoites were previously incubated for 1 h at 1, 5 and 10 µg/mL of PTS or PTSO and added to MDBK cells. In the second experiment, MDBK cells were first incubated for 24 h at different concentrations of PTS or PTSO and then infected with E. acervulina sporozoites. Then, 24 h after inoculation, the presence of E. acervulina was quantified by qPCR. MDBK viability was measured at 72 h post-infection. Sporozoites incubated at 10 µg/mL of PTS and PTSO inhibited the capability to penetrate the cells up to 75.2% ± 6.44 and 71.7% ± 6.03, respectively. The incubation of MDBK with each compound resulted in a preventive effect against sporozoite invasion at 1 µg/mL of PTS and 1 and 10 µg/mL of PTSO. Cells incubated with PTSO obtained similar viability percentages to uninfected cells. These results suggest that the use of PTS and PTSO is a promising alternative to coccidiosis treatment, although further in vivo studies need to be performed.

Thymol and carvacrol supplementation in poultry health and performance

BACKGROUND

Thymol and carvacrol as natural essential oils and phenol compounds are components derived from some medicinal plants, such as thyme and oregano species.

OBJECTIVES

The increasing demands in organic and healthy meat and egg consumption in human society have made it necessary to consider alternative natural compounds for the replacement of chemical compounds in poultry production. The chemical compounds can remain in meat and eggs and cause complications in human health. Therefore, these natural compounds can be fed with a higher safety in poultry production with specific effects. In this regard, the role of thymol and carvacrol as natural compounds in the poultry production has been discussed in the review.

METHODS

In this study, by searching for keywords related to thymol and carvacrol in poultry production in Google Scholar database, the articles related to different aspects of the biological effects of these two phytogenes in poultry production were selected and analyzed.

RESULTS

A review of previous studies has shown that thymol and carvacrol possess a wide range of biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, modulating of immunity response and regulating of the gut microbial population. Also, in meat type chickens can promote growth and influence feed utilization. The beneficial effect of this compound was evaluated in hepatic toxicity and demonstrated as a hepatoprotective compound in chickens. Furthermore, these compounds can affect the behavior of layers and influence egg composition, eggshell thickness, and the sensory quality of eggs.

CONCLUSION

It seems that with the increasing demand for healthy protein products, these compounds can be used to improve performance as a substitute alternative for chemical compounds in healthy poultry farms.

Curcumin, the active substance of turmeric: its effects on health and ways to improve its bioavailability

Turmeric (Curcuma longa L.) is a spice utilized widely in India, China, and Southeast Asia as an aromatic stimulant, a food preservative, and coloring material. The commonly used names of turmeric are castor saffron, turmeric, and saffron root. Turmeric is a yellow-orange polyphenolic natural substance derived from C. longa rhizomes. It has been used to treat common inflammatory diseases, tumors, biliary diseases, anorexia, cough, topical wounds, diabetic injuries, liver disorders, rheumatism, and sinusitis. Extensive studies on the biological properties and pharmacological consequences of turmeric extracts have been conducted in recent years. Curcumin, the primary yellow biocomponent of turmeric, has anti-inflammatory, antioxidant, anticarcinogenic, antidiabetic, antibacterial, antiprotozoal, antiviral, antifibrotic, immunomodulatory, and antifungal properties. Defense assessment tests showed that curcumin is tolerated well at high doses, without adverse effects. Thus, curcumin is a highly active biological material with the potential to treat different diseases in modern medicine. This review article focuses on curcumin's biological characteristics. The most popular methods for curcumin encapsulation are also discussed. Several effective techniques and approaches have been proposed for curcuminoid capsulation, including nanocomplexing, gelation, complex coacervation, electrospraying, and solvent-free pH-driven encapsulation. This review also highlights curcumin's chemical properties, allowing the readers to expand their perspectives on its use in the development of functional products with health-promoting properties. © 2021 Society of Chemical Industry.

A Systematic Review of Curcumin and its Derivatives as Valuable Sources of Antileishmanial Agents

BACKGROUND

In recent years, antimonial agents and other synthetic antileishmanial drugs, such as amphotericin B, paromomycin, and many other drugs, have restrictions in use due to the toxicity risk, high cost, and emerging resistance to these drugs. The present study aimed to review the antileishmanial effects of curcumin, its derivatives, and other relevant pharmaceutical formulations on leishmaniasis.

METHODS

The present study was carried out according to the 06-preferred reporting items for systematic reviews and meta-analyses (PRISMA) guideline and registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. Some English-language databases including PubMed, Google Scholar, Web of Science, EBSCO, Science Direct, and Scopus were searched for publications worldwide related to antileishmanial effects of curcumin, its derivatives, and other relevant pharmaceutical formulations, without date limitation, to identify all the published articles (in vitro, in vivo, and clinical studies). Keywords included "curcumin", "Curcuma longa", "antileishmanial", "Leishmania", "leishmaniasis", "cutaneous leishmaniasis", "visceral leishmaniasis", "in vitro", and "in vivo".

RESULTS

Out of 5492 papers, 29 papers including 20 in vitro (69.0%), 1 in vivo (3.4%), and 8 in vitro/in vivo (27.6%) studies conducted up to 2020, met the inclusion criteria for discussion in this systematic review. The most common species of the Leishmania parasite used in these studies were L. donovani (n = 13, 44.8%), L. major (n = 10, 34.5%), and L. amazonensis (n = 6, 20.7%), respectively. The most used derivatives in these studies were curcumin (n = 15, 33.3%) and curcuminoids (n = 5, 16.7%), respectively.

CONCLUSION

In the present review, according to the studies in the literature, various forms of drugs based on curcumin and their derivatives exhibited significant in vitro and in vivo antileishmanial activity against different Leishmania spp. The results revealed that curcumin and its derivatives could be considered as an alternative and complementary source of valuable antileishmanial components against leishmaniasis, which had no significant toxicity. However, further studies are required to elucidate this concluding remark, especially in clinical settings.

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.

Understanding the interactions between Eimeria infection and gut microbiota, towards the control of chicken coccidiosis: a review

The gastrointestinal tract in poultry harbours a diverse microbial community that serves a crucial role in digestion and protection. Disruption of the gut environment due to Eimeria spp. parasite infection causes an imbalance in intestinal homeostasis, driving the increment of pathogens such as Clostridium species. Coccidiosis infection affects the composition and integrity of gut microbiota, resulting in elevated susceptibility to diseases that pose a serious threat to the overall health and productivity of chickens. Anticoccidial drugs have proven effective in curbing coccidiosis but with concerning drawbacks like drug resistance and drug residues in meat. The exploration of natural alternative strategies such as probiotics and phytochemicals is significant in controlling coccidiosis through modification and restoration of gut microbiota, without inducing drug resistance. Understanding the interaction between Eimeria parasites and gut microbiota is crucial for the control and prevention of coccidiosis, and the development of novel alternative treatments.

Efficacy of a Dietary Polyherbal Formula on the Performance and Gut Health in Broiler Chicks after Experimental Infection with Eimeria spp

One-hundred and fifty, one-day-old Ross-308 female chicks were randomly allocated to five equal treatments: NCONTR negative control—not challenged; PCONTR positive control—challenged; PHERB1 and PHERB2 diets were supplemented with phytogenic formula (1 and 2 g/kg feed, respectively)—challenged; PSALIN diet was supplemented with salinomycin (60 mg/kg feed)—challenged. Challenge was made by oral inoculation with 3.5 × 10⁴E. acervulina, 7.0 × 10³E. maxima and 5.0 × 10³E. tenella oocysts, at 14 days of age. One week post inoculation, bloody diarrhea, oocysts numbers, and intestinal lesions were evaluated, along with intestinal microbiota, viscosity, and pH of digesta, and histopathology. PHERB2 had a comparable (p ≤ 0.001) growth performance and feed conversion ratio to PSALIN. PHERB1 and PHERB2 had similar (p ≤ 0.001) oocyst counts to PSALIN and lower than PCONTROL. PHERB2 and PSALIN had lower (p ≤ 0.001) jejunal, ileal, and cecal lesion scores compared to PCONTR. PHERB1 and PHERB2 had higher (p ≤ 0.001) jejunal and cecal lactobacilli and lower (p ≤ 0.001) coliform counts compared to other treatments. PCONTR had lower (p ≤ 0.001) jejunum villus height, height to crypt ratio, and villus goblet cells. Breast and thigh meat resistance to oxidation was improved (p ≤ 0.001) in PHERB1 and PHERB2 compared to the PCONTR. The polyherbal formula exerted a substantial improvement on growth performance and intestinal health of the Eimeria-challenged birds.

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 Study of Oregano and Garlic Essential Oils and Effects on Growth Performance, Fecal Oocyst Output, and Intestinal Microbiota in vivo

This study investigated the in vitro effects of Greek oregano and garlic essential oils on inhibition of Eimeria parasites and their in vivo effects on production performance, intestinal bacteria counts, and oocyst output. An inhibition assay was performed in vitro using Eimeria tenella Wisconsin strain sporozoites and Madin-Darby bovine kidney (MDBK) cells. Intracellular sporozoite invasion was quantified by detection of E. tenella DNA using qPCR from cell monolayers harvested at 2 and 24 h post-infection. Parasite invasion was inhibited by the oregano essential oil at the concentration of 100 μg/ml by 83 or 93% after 2 or 24 h, respectively. Garlic essential oil reached a maximum inhibition of 70% after 24 h with the 50 μg/ml concentration. Normal morphology was observed in MDBK cells exposed to concentrations of 100 μl/ml of garlic or oregano for over 24 h. In the in vivo trial, 180 male broiler chicks (45.3 ± 0.7 g) were allocated into two treatments (6 pens of 15 chicks per treatment). Control treatment was fed commercial diets without antibiotics or anticoccidials. The ORE-GAR treatment was fed the same control diets, further supplemented with a premix (1 g/kg feed) containing the oregano (50 g/kg premix) and garlic (5 g/kg premix) essential oils. At day 37, all birds were slaughtered under commercial conditions, and intestinal samples were collected. ORE-GAR treatment had improved final body weight (1833.9 vs. 1.685.9 g; p < 0.01), improved feed conversion ratio (1.489 vs. 1.569; p < 0.01), and reduced fecal oocyst excretion (day 28: 3.672 vs. 3.989 log oocysts/g, p < 0.01; day 37: 3.475 vs. 4.007 log oocysts/g, p < 0.001). In the caecal digesta, ORE-GAR treatment had lower total anaerobe counts (8.216 vs. 8.824 CFU/g; p < 0.01), whereas in the jejunum digesta the ORE-GAR treatment had higher counts of E. coli (5.030 vs. 3.530 CFU/g; p = 0.01) and Enterobacteriaceae (5.341 vs. 3.829 CFU/g; p < 0.01), and lower counts of Clostridium perfringens (2.555 vs. 2.882 CFU/g; p < 0.01). In conclusion, the combined supplementation of oregano and garlic essential oils had a potent anticoccidial effect in vitro and a growth-promoting effect in broilers reared in the absence of anticoccidial drugs.

Preliminary studies on in vitro methods for the evaluation of anticoccidial efficacy/resistance in ruminants

Ovine Eimeria spp. infections cause increased mortality, reduced welfare and substantial economic losses, and anticocccidials are important for their control. Recent reports of anticoccidial resistance against ovine Eimeria spp. necessitate the development of in vitro methods for the detection of reduced anticoccidial efficacy, especially since the in vivo methods are both expensive, time consuming and requires the use of otherwise healthy animals. The aim of the present study was therefore to approach a preliminary standardization of in vitro assays for evaluation of the efficacy of the most commonly used anticoccidials in ruminants. For this purpose, apart from the evaluation of inhibition of oocyst sporulation, most effort was concentrated on assessment of the capacity of the different anticoccidials to inhibit both the invasion and further development (up to the first schizogony) of E. ninakohlyakimovae sporozoites in bovine colonic epithelial cells (BCEC). For this purpose, infected cultures were monitored 1, 8 and 15 days post infection to determine the infection rate, number of immature schizonts and number, size and appearance of mature schizonts, respectively. No clear inhibitory effect was found with any of the anticoccidial formulations tested, and we could not identify why there were no measurable effects from the different anticoccidials. Despite the lack of positive results, further investigations should be encouraged, as this could decrease the need for animal experiments and could be used in the initial assessment of anticoccidial efficacy of new drugs.

Anti-coccidial properties and mechanisms of an edible herb, Bidens pilosa, and its active compounds for coccidiosis

Avian coccidiosis is an economically important disease in the poultry industry. In view of the disadvantages of anti-coccidial drugs in chickens, edible plants and their compounds are re-emerging as an alternative strategy to combat this disease. A previous publication reported that the edible plant B. pilosa showed promise for use against coccidiosis. Here, we first investigated into the anti-coccidial effects of B. pilosa. We found that B. pilosa at 100 ppm or more significantly suppressed E. tenella as evidenced by reduction in mortality rate, oocyst excretion and gut pathological severity in chickens and its minimum prophylactic duration was 3 days. Next, we explored the mode of action of anti-coccidial mechanism of B. pilosa. The E. tenella oocysts were not directly killed by B. pilosa; however, administration of the plant suppressed oocyst sporulation, sporozoite invasion, and schizonts in the life cycle of E. tenella. Besides, B. pilosa boosted T cell-mediated immunity. Finally, we characterized the related anti-coccidial phytochemicals and their mode of action. One of three potent polyynes present in B. pilsoa, Compound 1 (cytopiloyne), acted against coccidiosis in chickens in a similar manner to B. pilosa. These data illustrate the anti-coccidial potency and mechanism of B. pilosa and one of its active compounds, and provide a cornerstone for development of novel herbal remedies for avian coccidiosis.

Anticoccidial efficacy of Canary rue (Ruta pinnata) extracts against the caprine apicomplexan Eimeria ninakohlyakimovae

Continuous use of anticoccidial treatments against Eimeria infections has resulted in the development of drug resistance. This study aimed to evaluate the anticoccidial efficacy of a methanolic extract derived from the endemic Canary rue (Ruta pinnata) plant of the Canary Islands, Spain, against Eimeria ninakohlyakimovae using in vitro assays. Freshly unsporulated oocysts were exposed to different concentrations of R. pinnata extract and thereafter evaluated for sporulation inhibition. Additionally, anticoccidial activity was examined by testing the viability of the E. ninakohlyakimovae sporozoites and their ability to infect bovine colonic epithelial cells after incubation with different concentrations of R. pinnata plant extract. The inhibition of oocyst sporulation by the extract was both time and concentration dependent, with certain combinations affording the same levels of sporulation inhibition as formaldehyde used as positive control (P < 0.001). Moreover, concentrations >0.1 mg/mL also affected not only the viability of the sporozoites but also their cell invasion capacity (P < 0.001). Altogether, these results show that methanolic fruit extracts from R. pinnata have important anticoccidial activity against oocysts and sporozoites of Eimeria. The potential efficacy of the extracts against other animal/human parasites remains to be elucidated, and further studies are needed to better understand its mode of action against coccidian parasites.

In vitro study of anti-coccidial activity of essential oils from indigenous plants against Eimeria tenella

This study was designed to evaluate the in vitro anticoccidial properties against Eimeria tenella of different essential oils and their major active components. Efficacy of ten essential oils from different Thai indigenous plants were preliminarily screened and only those with potential were further tested for effective concentrations and identifying their active compounds. Oocysticidal property was evaluated in term of sporulation inhibition of oocysts and the percentage of unsporulated, sporulated and degenerated oocysts, after treatment with 125μg/ml of the selected essential oil, the sample was enumerated by haemocytometer, while coccidiocidal activity was assessed by the inhibition of sporozoite invasion in MDBK cell lines. Results showed that only Boesenbergia pandurata and Ocimum basilicum essential oils had strong sporulation inhibition activity by providing a higher ratio of degenerated oocysts and their IC₅₀ were 0.134 and 0.101mg/ml, respectively. GC-MS analysis of B. pandurata essential oil found trans-b-ocimene, camphor, 1,8-cineole, geraniol, camphene, methyl cinnamate, l-limonene and linalool as the major components, while methyl chavicol, α-bergamotene, 1,8-cineole and trans-β-ocimene were the main compounds of O. basilicum essential oil. Methyl cinnamate and camphor were the active components of B. pandurata oil, whereas methyl chavicol was the active component of O. basilicum oil by exhibiting the oocysticidal effect against E. tenella with IC₅₀ values of 0.008, 0.023 and 0.054mg/ml, respectively. Furthermore, B. pandurata and O. basilicum oils also showed a strong cytotoxic property against coccidia with more than 70% inhibition of sporozoite invasion in MDBK cell lines, and their IC₅₀ were 0.004 and 0.004mg/ml, respectively. Methyl cinnamate as well as camphor from B. pandurata and methyl chavicol from O. basilicum were also effective with IC₅₀ values of 0.029, 0.023, and 0.022mg/ml, respectively.

Effects of glass bead size, vortexing speed and duration on Eimeria acervulina oocyst excystation

Improved methods for efficient excystation of Eimeria should be developed and standardized for future Eimeria-related studies. Here, the effects of different glass bead sizes (0.5, 1, 2, and 2.5 mm), and various vortex speeds (1000, 2000, and 3000 rpm) and durations (30 s, 1, 3, and 5 min) have been examined for Eimeria (E.) acervulina oocyst excystation. At 3000 rpm, all glass beads, regardless of size, efficiently ruptured E. acervulina oocysts at 5 min. At 2000 and 3000 rpm, all four glass bead sizes increasingly ruptured oocysts in a time-dependent manner. In contrast, at 1000 rpm the excystation efficiency was not related with the glass bead size or with vortexing duration. It appeared that the 1mm glass beads are most efficient for E. acervulina DNA extraction at a 3000 rpm vortexing speed for 3 and 5 min. The 2 mm glass beads delicately released the highest number of intact sporocysts at 2000 rpm for 3 min. Therefore, our data can provide valuable information for the efficient mechanical excystation of E. acervulina.

Regulation of macrophage and dendritic cell function by pathogens and through immunomodulation in the avian mucosa

Macrophages (MPh) and dendritic cells (DC) are members of the mononuclear phagocyte system. In chickens, markers to distinguish MPh from DC are lacking, but whether MPh and DC can be distinguished in humans and mice is under debate, despite the availability of numerous markers. Mucosal MPh and DC are strategically located to ingest foreign antigens, suggesting they can rapidly respond to invading pathogens. This review addresses our current understanding of DC and MPh function, the receptors expressed by MPh and DC involved in pathogen recognition, and the responses of DC and MPh against respiratory and intestinal pathogens in the chicken. Furthermore, potential opportunities are described to modulate MPh and DC responses to enhance disease resistance, highlighting modulation through nutraceuticals and vaccination.