Inhibitory Effect of Hemiscorpius lepturus Scorpion Venom Fractions on Tachyzoites of Toxoplasma gondii.

Background: The present study determined the effect of the fractions obtained from Hemiscorpius lepturus scorpion venom on the tachyzoite of Toxoplasma gondii. Methods: The fractions of dried venom of He. lepturus scorpion of Khuzestan Province, southern Iran in 2019 were isolated through gel filtration chromatography, and then tachyzoites were exposed to fractions of venom at different concentrations. Trypan blue counting and MTT were applied to assay tachyzoite viability, and the inhibition of the cellular growth of fractions in Vero cells was evaluated. Results: The maximum effect on tachyzoite was observed in fraction 5 of venom. To further separate the protein, fraction 5 was used in high-performance liquid chromatography assay to purify its proteins. Based on the results of HPLC of fraction 5, among which the second peak, a peptide with <10 KDa representing a more potent effect in eliminating the tachyzoite of T. gondii. Conclusion: The scorpion venom-purified fractions possess anti-parasitic activity against the tachyzoite of T. gondii and can be used in parasite-controlling studies.

The potential therapeutic effect of adipose-derived mesenchymal stem cells in the treatment of cutaneous leishmaniasis caused by L. major in BALB/c mice.

Leishmaniasis is one of the most neglected tropical infectious diseases in the world. The emergence of drug resistance and toxicity and the high cost of the available drugs with a lack of new anti-leishmanial drugs highlight the need to search for newer therapies with anti-leishmanial activities. Due to the mesenchymal stem cell (MSC) immunomodulatory capacity, they have been applied in a wide variety of disorders. In this study, the potential effects of adipose-derived MSC (AD-MSCs) therapy and its combination with glucantime were evaluated in a murine model of cutaneous leishmaniasis induced by L. major. The results showed that AD-MSCs improved wound healing and decreased parasite burden. The real-time PCR results obtained from mice treated with AD-MSCs showed that IL-12 and TNF-α genes were upregulated. IL-10, arginase, and FOXP3 genes were downregulated whereas no differences in expression of the IL-4 gene were found. Overall, it seems that AD-MSCs therapy enhances Th1 immune response in L. major infected BALB/c mice. Unexpectedly, our results showed that the association of glucantime to AD-MSCs treatments did not lead to an increment in the anti-leishmanial activity.

In vitro antileishmanial activity of fisetin flavonoid via inhibition of glutathione biosynthesis and arginase activity in Leishmania infantum.

With the increasing emergence of drug resistant Leishmania sp. in recent years, combination therapy has been considered as a useful way to treat and control of Leishmaniasis. The present study was designed to evaluate the antileishmanial effects of the fisetin alone and combination of fisetin plus Meglumine antimoniate (Fi-MA) against Leishmania infantum. The IC50 values for fisetin were obtained 0.283 and 0.102 µM against promastigotes and amastigote forms, respectively. Meglumine antimoniate (MA, Glucantime) as control drug also revealed IC50 values of 0.247 and 0.105 µM for promastigotes and amastigotes of L. infantum, respectively. In order to determine the mode of action of fisetin and Meglumine antimoniate (MA, Glucantime), the activities of arginase (ARG), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) were measured. Moreover, intracellular glutathione (GSH) and nitric oxide (NO) levels in L. infantum-infected macrophages and L. infantum promastigotes which were treated with IC50 concentrations of fisetin, MA and Fi-MA were investigated. Our results showed that MA decreased CAT and SOD activity and increased NO levels in L. infantum-infected macrophages. In promastigotes, MA inhibited parasite SOD activity and reduced parasite NO production. The decreased levels of most of the antioxidant enzymes, accompanying by the raised level of NO in treated macrophages with MA, were observed to regain their normal profiles due to Fi-MA treatment. Furthermore, fisetin could prevent the growth of promastigotes by inhibition of ARG activity and reduction of GSH levels and NO production. In conclusion, these findings showed that fisetin improves MA side effects.

Amiodarone triggers induction of apoptosis in cutaneous leishmaniasis agents.

Leishmaniasis is a parasitic disease that is an important problem of public health worldwide. The aim of this study was to assess the cytotoxic effects of amiodarone (AMD) on Leishmania tropica (MHOM/AF/88/KK27) and L. major (MRHO/IR/75/ER) promastigotes and to observe the programmed cell death features. The colorimetric MTT assay was used to find L. tropica and L. major viability and the obtained results were expressed as 50% inhibitory concentration (IC50). Annexin-V FLUOS staining was performed to study the cell death properties of AMD using fluorescence-activated cell-sorting analysis. Qualitative analysis of the total genomic DNA fragmentation was performed by agarose gel electrophoresis. Furthermore, to observe changes in cell morphology, promastigotes were examined using light microscopy. The IC50 was achieved at 55 and 81 µM for L. tropica and L. major after 48 h of incubation, respectively. In both strains, AMD induced death with features of apoptosis, including externalization of phosphatidylserine, DNA laddering, and cell shrinkage. Our findings indicate that AMD may induce apoptosis on the causative agents of cutaneous leishmaniasis.

Detection of Sarcocystis spp. in cattle (Bos taurus) and water buffaloes (Bubalus bubalis) in Iran by PCR-RFLP.

Sarcocystis species are cyst-forming intracellular protozoan parasites. Cattle are mainly infected with Sarcocystis cruzi, Sarcocystis hominis and Sarcocystis hirsuta. Water buffaloes are intermediate hosts for Sarcocystis fusiformis, Sarcocystis levinei (S. cruzi-like species), Sarcocystis dubeyi, Sarcocystis sinensis (S. hominis-like species) and Sarcocystis buffalonis (S. hirsuta- like species). The aim of this study was Identification of Sarcocystis spp. in slaughtered cattle and water buffaloes in Ahvaz, Khuzestan province by PCR-restriction fragment length polymorphism. Meat inspection was done on 124 cattle and 147 water buffaloes. From each animal tissue samples (each 50 g) from heart, esophagus, diaphragm and intercostal muscle were collected during meat inspection. Samples examined with digestion method. Genomic DNA of 80 positive samples was extracted and their 18S rRNA gene was amplified. PCR products were digested by restricted enzymes (FokI, SspI and DraI). S. cruzi in cattle and S. fusiformis in water buffaloes were identified. Our study clarified that sarcocystosis in cattle in Ahvaz district may be results acute infection according to determined species, but in buffaloes as S. fusiformis was detected we may expect only economic loss follow up slaughterhouse inspection.

Designing and evaluation of Dot-ELISA for diagnosis of Fasciola infection in cattle.

Fasciolosis is a disease caused by liver fluck of the genus of Fasciola. Diagnosis of fasciolosis has been challenging for a long period due to low sensitivity of the coprological diagnostic method. In this study, an in-house Dot-ELISA method; using excretion-secretory (ES Ag) and Crude (Cr Ag) antigens of Fasciola was described for diagnosis of fasciolosis in cattle. For this purpose, the sera specimens of slaughtered cattle were taken and examined for Fasciola infection. Sera from two groups of cattle, one infected with Fasciola (n = 60) and the other non-infected with Fasciola (n = 60), were used in the Dot- ELISA test. All sera were tested and evaluated. Except specificity, other parameters such as, sensitivity, accuracy, positive and negative predictive values of Dot- ELISA with ES Ag were better than those of Dot- ELISA with Cr Ag. In conclusion, excretory-secretory antigen dependent Dot-ELISA can be used as a reliable sero-diagnostic test for Fasciola infection in cattle.

Seroprevalence of Toxoplasma gondii in water buffaloes (Bubalus bubalis) in South-West of Iran.

The prevalence of antibodies to Toxoplasma gondii was conducted in 300 buffaloes from Ahvaz, Kouzestan province, southwest of Iran. Blood sera were screened using a Modified agglutination test (MAT) incorporating 2-mercaptoethanol. Positive reactions in sera dilutions above 1:25 were considered as indicative for the presence of T. gondii antibodies. The overall prevalence of infection in the animals was 14.33% with titers of 1:25 in 21, 1:50 in 12, 1:100 in 6, 1:200 in 2 and 1:400 in 2. The prevalence was different in relation to the sex with buffaloes with 19.7% and 7% in females and males respectively. These results indicate that T. gondii infection in water buffaloes of Khouzestan is relatively high and consumption of buffalo meat may be a risk factor for humans in Ahvaz, southwest of Iran.

Occurrence of anti-Toxoplasma gondii antibodies in female cattle in south-west of Iran.

Toxoplasmosis, caused by Toxoplasma gondii, is a significant disease in livestock and humans. In Iran, studies shows that T. gondii infection in humans is relatively high and prevalence is associated mainly with consumption of undercooked meat or meat products. We have examined 450 serum samples from female cattle distributed over all Ahvaz, the center of Khouzestan province, south-west of Iran. IgG antibodies to T. gondii were assayed by the modified agglutination test using whole tachyzoites of T. gondii, and found in 71 (15.77%) of 450 cattle with titers of 1:25 in 38, 1:50 in 18, 1:100 in 11, 1:200 in three and 1:400 in one. Titers of antibodies were decreased in cattle over 2 years old. These results indicate that T. gondii infection in cattle of Khouzestan is relatively considerable, but not very high and consumption of beef may be a source of infection for humans in south-west of Iran.