Tandem mass tag-based quantitative proteomics analyses of a chicken-original virulent and its attenuated Histomonas meleagridis strain in China.

Introduction: Histomonas meleagridis can cause histomonosis in poultry. Due to the prohibition of effective drugs, the prevention and treatment of the disease requires new strategies. Questions about its pathogenic mechanisms and virulence factors remain puzzling. Methods: To address these issues, a tandem mass tag (TMT) comparative proteomic analysis of a virulent strain and its attenuated strain of Chinese chicken-origin was performed. Results: A total of 3,494 proteins were identified in the experiment, of which 745 proteins were differentially expressed (fold change ≥1.2 or ≤0.83 and p < 0.05), with 192 up-regulated proteins and 553 down-regulated proteins in the virulent strain relative to the attenuated strain. Discussion: Surface protein BspA like, digestive cysteine proteinase, actin, and GH family 25 lysozyme were noted among the proteins up regulated in virulent strains, and these several proteins may be directly related to the pathogenic capacity of the histomonad. Ferredoxin, 60S ribosomal protein L6, 40S ribosomal protein S3, and NADP-dependent malic enzyme which associated with biosynthesis and metabolism were also noted, which have the potential to be new drug targets. The up-regulation of alpha-amylase, ras-like protein 1, ras-like protein 2, and involucrin in attenuated strains helps to understand how it is adapted to the long-term in vitro culture environment. The above results provide some candidate protein-coding genes for further functional verification, which will help to understand the molecular mechanism of pathogenicity and attenuation of H. meleagridis more comprehensively.

Evaluation of Origanum vulgare Essential Oil and Its Active Ingredients as Potential Drugs for the Treatment of Toxoplasmosis.

Toxoplasma gondii is a serious hazard to public health and animal husbandry. Due to the current dilemma of treatment of toxoplasmosis, it is urgent to find new anti-T. gondii drugs to treat toxoplasmosis. In this study, the anti-T. gondii activity of Origanum vulgare essential oil (Ov EO) was firstly studied, and then, carvanol (Ca), the main ingredient of Ov EO was evaluated using the MTT assay on human foreskin fibroblast (HFF) cells in vitro. The cytotoxicity was evaluated using the MTT assay on HFF cells. The CC50 of Ov EO and Ca was 134.9 and 43.93 µg/ml, respectively. Both of them exhibited anti-parasitic activity, and inhibited the growth of T. gondii in a dose-dependent manner. For the inhibition effect, Ca was better than Ov EO at the same concentration, the IC50 of Ov EO and Ca was 16.08 and 7.688 µg/ml, respectively. In addition, treatment with Ca, was found to change the morphology of T. gondii tachyzoites and made their shapes curl up. These results showed that Ca was able to inhibit the proliferation of T. gondii by reducing invasion, which may be due to its detrimental effect on the mobility of tachyzoites. Our results indicated that Ca could be a potential new and effective drug for treating toxoplasmosis.

In Vitro Evaluation of Lavandula angustifolia Essential Oil on Anti-Toxoplasma Activity.

The current methods of treating toxoplasmosis have a number of side effects, and these therapies are only effective against the acute stage of the disease. Thus, development of new low toxicity and efficient anti-Toxoplasma drugs is extremely important. Natural products are important sources for screening new drugs; among them, essential oils (EOs) have efficacy in anti-bacterial, anti-inflammatory, anti-insect, and other aspects. In this study, 16 EOs were screened for their anti-T. gondii activity. Lavandula angustifolia essential oil (La EO)was found to have an anti-parasitic effect on T. gondii. The cytotoxicity of La EO was firstly evaluated using the MTT assay on human foreskin fibroblast (HFF) cells, and then the anti-T. gondii activity was evaluated by plaque assay. Finally, the invasion experiment and electron microscope observation were used to study the mechanism of La EO in anti-toxoplasma activity. The results indicated that the CC50 of La EO was 4.48 mg/ml and that La EO had activity against T. gondii and the inhibition was in a dose-dependent manner under safe concentrations. La EO was able to reduce T. gondii invasion, which may be due to its detrimental effect on changes of the morphology of tachyzoites. These findings indicated that La EO could be a potential drug for treating toxoplasmosis.

In vitro Anti-parasitic Activity of Pelargonium X. asperum Essential Oil Against Toxoplasma gondii.

Toxoplasmosis is a global zoonotic disease, and one-third of the human population is chronically infected by Toxoplasma gondii. Due to the limited effectiveness and prominent side effects of the existing drugs, there is a dire need for the discovery of new therapeutic options in the treatment of toxoplasmosis. In this study, five essential oils (EO) were screened for their anti-parasitic activity against T. gondii. The cytotoxicity of essential oils was evaluated using the MTT assay on human foreskin fibroblast cells. The CC50 values of Eucalyptus globulus EO, Cupressus sempervirens EO, Citrus aurantifolia EO, Melaleuca alternifolia EO, and Pelargonium X. asperum (Pa) EO were found to be 22.74, 7.25, 15.01, 6.26, and 4.77 mg/mL, respectively. Only PaEO exhibited anti-parasitic activity, and inhibited the growth of T. gondii in a dose-dependent manner. In addition, treatment with PaEO, was found to reduce the volume of T. gondii tachyzoites and make their membrane surfaces rough. These results showed that PaEO was able to inhibit the growth of T. gondii by reducing invasion, which may be due to its detrimental effect on the ability of tachyzoites to move. These findings suggest that PaEO could be a potential anti-T. gondii drug, which may facilitate the development of new and effective treatments against toxoplasmosis.