Dimedone nanoparticle as a promising approach against toxoplasmosis: In vitro and in vivo evaluation

Toxoplasma gondii, an intracellular parasite, has shown drug resistance and therapeutic failure in recent years. Dimedone (DIM) has been introduced as a new chemical compound with anti-bacterial and anti-cancer properties. The aim of this study was to investigate the potential protective role of DIM nanoparticles in an animal model of toxoplasmosis. Cytotoxicity of DIM on Vero cell line assessed using MTT, and the effect of DIM on Toxoplasma gondii was evaluated by counting the number of parasites compared to the control group in vitro. The rate of pathogenesis and virulence of the parasite was checked on the liver cells of the animal model using hematoxylin-eosin staining. Furthermore, various parameters indicating oxidative stress were compared in mouse liver tissue in different groups. The release of the nanoparticle form was significantly longer than the free drugs. The IC50 of Nano-DIM was 60 µM and the reduction of intracellular parasite proliferation in the group Nano-DIM and Nano-PYR (Nano-primethamine) was significantly lower than the free drugs in vitro. Histopathology examination in the groups treated with dimedone nanomedicine showed that the degree of disintegration of the epithelium of the central vein of the liver and infiltration and vacuolization of liver cells were lower compared to the toxoplasmosis group. Additionally, the level of some oxidative stress indicators was observed to be lower in the nano-treated groups compared to other groups. The results of this study showed DIM can be used as a promising compound for anti-T. gondii activity and can prevent the proliferation of it in cells.

Toxoplasma gondii attenuates the ethidium bromide induced demyelination lesions in multiple sclerosis model rats

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease. Since the modulation of the immune system by parasites has been proven, and there have been reports of a reduction in the clinical symptoms of MS in people with toxoplasmosis, this study aimed to investigate the effect of toxoplasmosis on MS in an animal model. MS model was induced by the ethidium bromide injection in the areas specified in the Rat's brain in the stereotaxic device and Toxoplasma gondii RH strain injection of the rat's peritoneal for creation of toxoplasmosis. The effect of acute and chronic toxoplasmosis on the MS model was evaluated by examining the development of clinical symptoms of MS, body weight, changes in the levels of inflammatory cytokines, inflammatory cell infiltration, cell density, and spongy tissue in the brain. The body weight in the acute toxoplasmosis with MS was the same as the MS group, and a significant decrease was observed, but no weight loss was observed in the chronic toxoplasmosis with MS. In the chronic toxoplasmosis, the progress of clinical signs such as Immobility of limbs, including tail, hands, and feet, was observed less compared to other groups. The histology results in the group of chronic toxoplasmosis showed high cell density and inhibition of spongy tissue formation, and the infiltration of inflammatory cells in this group was less. TNF-α and INF-γ decreased in MS with chronic toxoplasmosis compared to the MS group. Our findings showed that chronic toxoplasmosis with inhibition of spongy tissue formation and prevention of cell infiltration and. As a result, the reduction of inflammatory cytokines could reduce clinical symptoms in MS in the animal model.

Sarcocystis bovifelis in Raw Hamburgers Marketed in Hamadan City, Western Iran

Background: We aimed to evaluate Sarcocystis contamination in conventional and industrial raw beef burger samples from butcheries and retail stores in Hamadan, western Iran. Methods: Overall, 80 samples including 30 conventional and 50 industrial hamburgers were randomly obtained from different butcheries and supermarkets. All specimens were studied by digestion method following microscopic examination. Samples` genomic ribosomal DNA were amplified and nucleotide sequences were analyzed by BLAST for comparison with the sequences in the gene bank of the NCBI. Results: Sarcocystis bradyzoites were detected in 46 of 80 (57.6%) samples. Positive specimens were included as 46 (57.6%) and 30 (37.5%) by digestion and molecular method, respectively. Differences between two studied (digestion and molecular) methods was statistically significant (P=0.00). Twenty-six (86.5 %) of 30 conventional beef burgers and 20 (40%) of 50 industrial burgers were positive for Sarcocystis sp. by digestion method. There was a significant difference between Sarcocystis infested conventional and industrial beef burgers (P=0.01). Conclusion: The parasitic contamination of beef burgers implied a high level of infection in cattle. Felids as the definitive hosts for S. bovifelis urged on the improvement of the hygienic conditions of keeping and feeding livestock in order to reduce the infection. Molecular techniques confirm species in meat products with high sensitivity and distinguish it from human species.

Co Expression of GMFβ, IL33, CCL2 and SDF1 Genes in the Acute Stage of Toxoplasmosis in Mice Model and Relation for Neuronal Impairment

Background

Toxoplasma gondii is an obligate intracellular parasite that migrates through macrophages or dendritic cells to neurons and nerve cells. Glia Maturation Factor (GMF) is a pre-inflammatory protein that is expressed in the central nervous system (CNS). GMFβ expression is related to IL33 and CCL2 and SDF1 in some neurodegenerative diseases. According to the importance of GMFβ in neurodegenerative diseases and its association with IL33, CCL2 and SDF1 genes, this study was designed to determine the level of expression of these genes in the brains of mice with acute toxoplasmosis.

Methods

Tachyzoites of T. gondii RH strains were injected to 5 Swiss Albino mice. At the same time, healthy mice were inoculated with the Phosphate-buffered saline (PBS). Their brains were removed and kept at -70 °C in order to RNA extraction, cDNA syntheses and Real Time PCR performance. The level of gene expression was investigated with SYBR Green Quantitative Real-Time PCR.

Results

GMFβ gene expression increased significantly (P=0.003) 3.26 fold in Toxoplasma infected mice in comparison to the control. GMFβ gene expression was associated with increased expression level of IL33, CCL2, and SDF1 genes.

Conclusion

Considering the prominent role of GMFβ in CNS as well as the immune system, the elevation of GMFβ, IL33, CCL2 and SDF1 genes expression in the early stage of toxoplasmosis is associated with the occurrence of neuropathological alterations. Detection of these genes as an indication of brain damage in the early stages of Toxoplasma infection can prevent neurodegenerative disorders following acquired toxoplasmosis.

Toxoplasma gondii induced sperm DNA damage on the experimentally infected rats

Toxoplasma gondii, as an obligate protozoan parasite, can infect a wide variety of animals as well as human. As some studies have shown, toxoplasmosis decreases the fertility potency in different hosts, so there is a necessity for studies to determine the effects of T. gondii on reproductive system. Therefore, this project was aimed to investigate the effect of toxoplasmosis on the male reproductive system and sperm DNA integrity. In this experimental study, 80 Wistar male rats were divided into two groups as follows: infected group (inoculated by T.gondii tachyzoites) and control group [injected by Phosphate-buffered saline (PBS)]. Afterward, data were collected in every 10 days interval. The detailed description of the sperm parameters were recorded, and then, chromatin integrity of the epididymal sperm was analyzed using Aniline blue (AB), Acridine orange (AO), Chromomycin A3 (CMA3), and Toluidine blue (TB) staining. Sperm parameters (motility, viability, count, and normal sperm) significantly decreased in the infected rats. Sperm stained by AO staining showed a higher percentage in the infected rats compared to the control group on day 70 (P = 0.03). The mean percentages of AB stained sperm on days 30 (P = 0.01) and 50 (P = 0.02) were higher than the healthy group. Also, the significant rising of the stained sperm was observed in the infected group on day 20 (P = 0.01). Sperm stained with TB in the infected group has significantly increased on days 30 to 60 [day 30 (P = 0.001), 40 (P < 0.001), 50 (P = 0.014), and 60 (P = 0.001)]. T. gondii infection leads to the diminished fertility parameters as well as the damaged DNA sperm. The parasite could temporarily interfere with the male reproductive system.

Toxoplasma gondii: A Possible Inducer of Oxidative Stress in Reproductive System of Male Rats

Background:

Toxoplasmosis is suspected to have adverse effects on the male reproductive system. We aimed to determine the possible role of Toxoplasma gondii in oxidative stress in reproductive system of male rats.

Methods:

This study was performed from 2018 until 2019 at the Parasitology Research Laboratory of Hamadan University of Medical Sciences, Hamadan, Iran. Eighty male Wistar rats were randomly divided to control and test groups. The animals in the test group were inoculated by 10⁷T. gondii RH strain tachyzoites and the control group were injected by 0.2 ml of phosphate-buffered saline. The both groups were following every 10 days until day 80 post inoculation. Oxidative stress markers (OSMs) including antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and nonenzymatic markers including malondialdehyde (MDA), reduced glutathione (GSH) and total antioxidant capacity (TAC) were assessed in testis and serum of T. gondii infected rats.

Results:

After post inoculation, the variations of the OSMs in the testis tissue of infected rats were as follows: a significant decrease of SOD on day 80 (P=0.03), and CAT activity were detected on day 60 and 80 (P=0.04 and P=0.01) respectively. In addition, GSH (P =0.01) and TAC (P =0.03) concentration were significantly reduced on day 80. On the contrary, the concentration of MDA (P =0.01) was increased 70 days after infection. In addition, consistent changes with the tissue testis were observed in the serum OSMs of infected rats.

Conclusion:

T. gondii infection caused oxidative stress in testis tissue. Thus, the adverse effects of oxidative stress may affect the male rat reproductive system.

FML-ELISA a novel diagnostic method for detection of feline leishmaniasis in two endemic areas of Iran

Although canids are regarded as major reservoir hosts for Leishmania infantum, feline leishmaniasis are reported sporadically from different endemic foci of Mediterranean visceral leishmaniasis (VL). Despite the risk of parasite transmission between human and other animals, most of the studies are limited to dogs and few studies are focused to investigate Leishmania sp. among other mammals. This project was aimed to detect L. infantum antibodies of cats in two VL endemic regions of Iran by Fucose Mannose Ligand (FML) and soluble L. infantum antigen (SLA) ELISA. Forty nine stray cats of different age and sex, from Fars and Ardabil provinces (two VL endemic loci of Iran) were sampled, then tested for L. infantum by FML and SLA-ELISA. Sixteen percent (8/49) of cat sera were reported positive by FML-ELISA. SLA-ELISA showed 18.3% (9/48) positive cases in cats. Sensitivity of FML-ELISA was calculated 57% and SLA ELISA 25%. Specificity of FML and SLA ELISA were assessed 78% and 68% respectively. Kappa coefficient of agreement between FML and SLA-ELISA was detected on 0.45. As feline leishmaniasis could be a potential risk in endemic areas, FML-ELISA could be considered as an appropriate examination to detect leishmaniasis in cats.

Leishmania infantum FML pulsed-dendritic cells induce a protective immune response in murine visceral leishmaniasis

AIM

To investigate the efficacy of FML loaded dendritic cells (DCs) in protection against visceral leishmaniasis.

MATERIALS & METHODS

Mice were immunized with FML- or soluble Leishmania antigen-loaded DCs as well as FML or soluble Leishmania antigen in saponin and challenged with parasite. The levels of cytokines before and after challenge were detected by ELISA. Parasite burden (total Leishman-Donovan unit) was determined after parasite challenge.

RESULTS

FML-saponin induced the highest IFN-γ/IL-4 ratio among vaccinated groups, though this ratio was higher in FML-loaded DCs group subsequent to challenge with Leishmania infantum. Moreover, the greatest reduction in parasite number was detected in mice vaccinated with FML-loaded DCs compared with phosphate-buffered saline-treated mice (p = 0.002).

CONCLUSION

FML-loaded DCs are one of the promising tools for protection against murine visceral leishmaniasis.