Immunomodulatory and antiparasitic effects of garlic extract on Eimeria vermiformis-infected mice

Garlic essential oil ameliorates depression-like behaviors in unpredictable chronic mild stress by modulating the brain NLRP3 inflammasome pathway and influencing the gut barrier and microbiota

Depression is a severe mental disorder, with approximately 300 million people suffering from it. Recent studies have demonstrated that chronic neuroinflammation is significantly associated with intestinal flora and barrier function in depression. As a therapeutic herb, garlic (Allium sativum L.) has detoxification, antibacterial activity, and antiinflammatory functions; however, its antidepressant effect through gut microbiota and barrier function has not been reported yet. The present study investigated the effect of garlic essential oil (GEO) and its active constituent diallyl disulfide (DADS) on depressive behavior by attenuating the NLRP3 inflammasome, alternating intestinal barrier function and gut microbiota in an unpredictable chronic mild stress (US) model in rats. This study found that dopamine and serotonin turnover rates were reduced significantly with a low dose of GEO (25 mg per kg bw). The GEO groups effectively reversed sucrose preference and increased the total distance traveled in the behavioral test. Moreover, 25 mg per kg bw GEO inhibited the UCMS-induced activated inflammatory response, reflected by reduced expression in the frontal cortex of NLRP3, ASC, caspase-1, and its downstream IL-1β proteins, as well as the concentration of IL-1β and TNF-α in the serum. Supplementation with GEO increased the expression of occludin and ZO-1 and the concentration of short-chain fatty acids to influence the impact of intestinal permeability in depressive conditions. The results revealed that GEO administration caused significant changes in the α and β diversity and abundance of certain bacteria. At the genus level, GEO administration significantly increased the relative abundance, particularly beneficial SCFA-producing bacteria, and may improve depression-like behavior. In conclusion, these results indicated the antidepressant effects of GEO involved in the inflammatory pathway, short-chain fatty acids, intestinal integrity, and intestinal composition.

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.

Alterations in the jejunal microbiota and fecal metabolite profiles of rabbits infected with Eimeria intestinalis

Background

Rabbit coccidiosis is a major disease caused by various Eimeria species and causes enormous economic losses to the rabbit industry. Coccidia infection has a wide impact on the gut microbiota and intestinal biochemical equilibrium. In the present study, we established a model of Eimeria intestinalis infection in rabbits to evaluate the jejunal microbiota and fecal metabolite profiles.

Methods

Rabbits in the infected group were orally inoculated with 3 × 10³E. intestinalis oocysts. On the eighth day of infection, jejunal contents and feces were collected for 16S rRNA gene sequencing and liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis, respectively. Jejunum tissues were harvested for hematoxylin and eosin (H&E), periodic acid-Schiff (PAS), and immunohistochemistry (IHC) staining.

Results

Histopathological analysis showed that the whole jejunum was parasitized by E. intestinalis in a range of life cycle stages, and PAS staining showed that E. intestinalis infection caused extensive loss of goblet cells. IHC staining revealed that TNF-α expression was higher in the E. intestinalis infection group. Moreover, both the jejunal microbiota and metabolites significantly altered after E. intestinalis infection. At the genus level, the abundances of Escherichia and Enterococcus significantly increased in the infected group compared with the control group, while those of Oscillospira, Ruminococcus, Bacteroides, Akkermansia, Coprococcus, and Sarcina significantly decreased. In addition, 20 metabolites and two metabolic pathways were altered after E. intestinalis infection, and the major disrupted metabolic pathway was lipid metabolism.

Conclusions

Eimeria intestinalis infection induced intestinal inflammation and destroyed the intestinal homeostasis at the parasitized sites, leading to significant changes in the gut microbiota and subsequent corresponding changes in metabolites.

Graphical Abstract

Eimeria infections in domestic and wild ruminants with reference to control options in domestic ruminants

Eimeria infections are commonly seen in a variety of mammalian hosts. This genus of unicellular sporozoan parasites causes significant disease (coccidiosis) in different livestock species leading to economic losses for agricultural producers. Especially the production of cattle, sheep, and goat is strongly dependent on efficient coccidiosis control. However, many other livestock hosts like, e.g., camelids, bison, rabbits, and guinea pigs may benefit from reduced parasite transmission and targeted control measures as well. Besides livestock, also wildlife and pet animals may be affected by Eimeria infections resulting in clinical or subclinical coccidiosis. Wildlife herd health is crucial to conservation efforts, and Eimeria species are a prevalent pathogen in multiple mammalian wildlife species. This review aims to highlight the epidemiology of mammalian Eimeria infections in both wild and domestic ruminants, including host specificity, transmission, survival of environmental oocysts, occurrence, and risk factors for infection. Understanding general drivers of Eimeria infection may support adequate livestock and wildlife management. Furthermore, control options for livestock with reference to management factors, drug application, and alternative approaches are discussed. The goal of Eimeria control should be to reduce pathogen transmission in different host species and to improve sustainable livestock production. Controlling Eimeria infections in livestock is important considering both their animal welfare impact and their high economic relevance.

Immunomodulatory effects of Allium Sativum L. and its constituents against viral infections and metabolic diseases

BACKGROUND

Allium sativum L., or garlic, is one of the most studied plants worldwide within the field of traditional medicine. Current interests lie in the potential use of garlic as a preventive measure and adjuvant treatment for viral infections, e.g., SARS-CoV-2. Even though it cannot be presented as a single treatment, its beneficial effects are beyond doubt. The World Health Organization has deemed it an essential part of any balanced diet with immunomodulatory properties.

OBJECTIVE

The aim of the study was to review the literature on the effects of garlic compounds and preparations on immunomodulation and viral infection management, with emphasis on SARS-CoV-2.

METHOD

Exhaustive literature search has been carried out on electronic databases.

CONCLUSION

Garlic is a fundamental part of a well-balanced diet which helps maintain general good health. The reported information regarding garlic's ability to beneficially modulate inflammation and the immune system is encouraging. Nonetheless, more efforts must be made to understand the actual medicinal properties and mechanisms of action of the compounds found in this plant to inhibit or diminish viral infections, particularly SARS-CoV-2. Based on our findings, we propose a series of innovative strategies to achieve such a challenge in the near future.

Improving the bioavailability and bioactivity of garlic bioactive compounds via nanotechnology

This review highlights main bioactive compounds and important biological functions especially anticancer effects of the garlic. In addition, we review current literature on the stability and bioavailability of garlic components. Finally, this review aims to provide a potential strategy for using nanotechnology to increase the stability and solubility of garlic components, providing guidelines for the qualities of garlic products to improve their absorption and prevent their early degradation, and extend their circulation time in the body. The application of nanotechnology to improve the bioavailability and targeting of garlic compounds are expected to provide a theoretical basis for the functional components of garlic to treat human health. We review the improvement of bioavailability and bioactivity of garlic bioactive compounds via nanotechnology, which could promisingly overcome the limitations of conventional garlic products, and would be used to prevent and treat cancer and other diseases in the near future.

Ethnoveterinary perspectives and promising future

In this review, we have discussed the recent potential effects of plants and their derivatives in treating diseases of veterinary importance in livestock. The therapeutic value of these natural products depends upon their bioactive metabolites that are developed and isolated from crude plants, thus produced a selective action on the body. The crises of drug resistance in most pathogenic bacteria and parasites that cause economic loss in animals necessitate developing new sources for drugs to overcome therapeutic failure. We summarized the different antibacterial and antiparasitic plants with their bioactive compounds that have widely used in animals. Finally, the environmental friendly feed additives that may be used as alternatives to an antibiotic growth promoter for broiler chickens were illustrated.

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.

Anticoccidial activities of Chitosan on Eimeria papillata-infected mice

Eimeria spp. multiply within the intestinal tract causing severe inflammatory responses. Chitosan (CS), meanwhile, has been shown to exhibit anti-inflammatory activities in different experimental models. Here, we investigated the effect of CS on the outcome of inflammation caused by Eimeria papillata in the mouse intestine. Investigations were undertaken into the oocyst output in feces and developmental stages and goblet cells in intestinal tissue. Assays for lipid peroxidation, nitric oxide (NO), and myeloperoxidase (MPO) were also performed. T cells in intestinal tissue were counted using immunohistochemistry while total IgA in serum or intestinal wash was assayed using ELISA. In addition, mRNA expression of tumor necrosis factor alpha (TNF-α), transforming growth factor β (TGF-β), interleukin (IL)-10, and IL-4 were detected using real-time PCR. The data indicated a reduction in both oocyst output and in the number of parasite developmental stages following CS treatment, while the goblet cell hypoplasia in infected mice was also inhibited. CS decreased lipid peroxidation, NO, and MPO but did not alter the T cell count or IgA levels in comparison to the infected group. The expression of TNF-α and TGF-β decreased but IL-10 and IL-4 increased after CS treatment in comparison to the non-treated infected group. In conclusion, CS showed anti-inflammatory and protective effects against E. papillata infection.

In vitro efficacy of allicin on chicken Eimeria tenella sporozoites

Chicken coccidiosis is a major parasitic disease caused by Eimeria spp. It is controlled and treated using chemical anticoccidial agents. Development of partial or complete resistance toward these anticoccidials is considered a major problem in poultry industry. Allicin is an organosulfur compound produced as a result of the reaction between alliin and alliinase after hacking of garlic. In this study, tenfold dilution from 180 mg/ml to 1.8 ng/ml of allicin in distilled water was tested against E. tenella in vitro. The percent of inhibition in allicin was from 99.9 to 71.53% using 180 mg/ml and 180 ng/ml, respectively. The percent of inhibition was 56.24% using 1.8 ng/ml. We used allicin as a treatment from plants against chicken coccidiosis; however, in vivo study should be performed to confirm these results.