Artesunate effect on schistosome thioredoxin glutathione reductase and cytochrome c peroxidase as new molecular targets in schistosoma mansoni-infected mice / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the possible effect of artesunate (ART) on schistosome thioredoxin glutathione reductase (TGR) and cytochrome c peroxidase (CcP) in Schistosoma mansoni-infected mice.</p><p><b>METHODS</b>A total of 200 laboratory bred male Swiss albino mice were divided into 4 groups (50 mice in each group). Group I: infected untreated group (Control group) received a vehicle of 1% sodium carbonyl methylcellulose (CMC-Na); Group II: infected then treated with artesunate; Group III: infected then treated with praziquantel, and group IV: infected then treated with artesunate then praziquantel. Adult S. mansoni worms were collected by Animal Perfusion Method, tissue egg counted, TGR, and CcP mRNA Expression were estimated of in S. mansoni adult worms by semi-quantitative rt-PCR.</p><p><b>RESULTS</b>Semi-quantitative rt-PCR values revealed that treatment with artesunate caused significant decrease in expression of schistosome TGR and CcP in comparison to the untreated group. In contrast, the treatment with praziquantel did not cause significant change in expression of these genes. The results showed more reduction in total worm and female worm count in combined ART-PZQ treated group than in monotherapy treated groups by either ART or PZQ. Moreover, complete disappearance (100%) of tissue eggs was recorded in ART-PZQ treated group with a respective reduction rate of 95.9% and 68.4% in ART- and PZQ-treated groups.</p><p><b>CONCLUSION</b>The current study elucidated for the first time that anti-schistosomal mechanisms of artesunate is mediated via reduction in expression of schistosome TGR and CcP. Linking these findings, addition of artesunate to praziquantel could achieve complete cure outcome in treatment of schistosomiasis.</p>

Artesunate effect on Schistosome thioredoxin glutathione reductase and cytochrome-C peroxidase as new molecular targets in Schistosoma mansoni infected mice

Schistosomiasis remains one of the most important parasitic diseases. Extensive use of praziquantel [PZQ] with concerns about possibility of drug resistance development, unavailability of an applicable vaccine, and absence of a reasonable alternative to PZQ, all represent a real challenge in control of schistosomiasis. Artemisinin derivatives are promising anti-schistosomal compounds, but their molecular mechanism of action on schistosomes is still not well defined. This study investigated the possible effect of artesunate [ART] on schistosome thioredoxin glutathione reductase [TGR] and cytochrome c peroxidase [CcP] in Schistosoma mansoni-infected mice. The animals used were divided into four groups. Group I: infected untreated group [control group]; group II: infected then treated with ART; group III: infected then treated with PZQ; and group IV: infected then treated with both ART and PZQ. ART was given orally in four doses, each of 300 mg/kg starting at 14th day post-infection [PI] and then every 2 weeks. PZQ was given orally in a single dose of 600 mg/kg at 42nd day PI. Then all mice were subjected to the following: adult S. mansoni worm count at 10 weeks PI, tissue egg count in liver and estimation of TGR and CcP mRNA expression in S. mansoni adult worms by semi-quantitative real time-PCR [rt-PCR]. Semi-quantitative rt-PCR values revealed that treatment with ART caused significant decrease in expression of schistosome TGR and CcP in contrast to PZQ which did not cause significant change in their expression. In addition, there was more reduction in total and female worm counts in ART-PZQ treated group than in other treated groups. Moreover, complete disappearance [100%] of tissue eggs was recorded in ART-PZQ treated group with a respective reduction rate of 95.9% and 68.4% in ART- and PZQ-treated groups. The current study elucidated for the first time that anti-schistosomal mechanism of action of ART is mediated via reduction in expression of schistosome TGR and CcP. Linking these findings, the addition of ART to PZQ could achieve complete cure outcome in treatment of schistosomiasis

Potential effect of Curcuma longa extract on infectivity and pathogenicity of Schistosoma mansoni cercariae

Batch of freshly shed cercariae from infected laboratory bred Biomphalaria alexandrina were exposed to different sub-lethal concentrations of turmeric extract for an hour and divided into two groups. The first one was to study the ultrastructural changes induced in them using scanning electron microscopy [SEM]. The second group was to study infectivity and pathogenicity of the exposed cercariae. One hundred and fifty mice were divided into 5 groups: GI: Infected by normal cercariae and served as controls; GII, GIII, GIV and GV infected by cercariae exposed to 2.5, 5, 7.5 and 10 ppm, respectively. Ten weeks post infection all animals were sacrificed and subjected to parasitologic, histopathologic and immunologic assays. SEM showed cercariae exposed to 5ppm with minimal destruction of head spines and tail. The degenerative changes were progressively severe by increasing extract concentration to reach complete destruction of both at 10 ppm. Infectivity decreased with the increase in concentration to reach highest significance at 10 ppm. Pathogenicity or mean number of egg deposited, mean diameter of liver granulomas and level of IL-10 gene expression significantly decreased in Gs IV and V

Effect of organochlorine [DDT] exposure on experimental giardiasis

This work studied the effect of sub-chronic DDT exposure on the course of experimental giardiasis and efficacy of its treatment. A total of 160 mice were divided into six groups: G1: 30 mice received DDT and infected with Giardia lamblia. G2: 30 mice received DDT, infected and treated with tinidazole [TNZ]. G3: 30 mice infected with Giardia. G4: 30 mice infected and treated with TNZ. G5: 30 mice received DDT only. G6: 10 mice served as normal control. Mice were sacrificed at 7, 14, 21 and 28 days P.I. All groups were subjected to cyst count/2 hours collected stool, trophozoite count in intestine, histopathological examination of small intestinal section and avidin biotin peroxidase technique for local IgA staining. Also, IFN-gama was measured in sera. DDT caused early shedding of many cysts and increase in trophozoite counts for a long time, decreased intra epithelial lymphocytes, low levels of IgA and IFN-gama and severe histopathological changes in intestinal sections in G1 as compared to G3. Also, DDT reduced the efficacy of TNZ treatment in G2 as compared to G4. The results strongly support the immunomodulating effect of DDT on experimental giardiasis that might be responsible for persistence of infection, resistance to treatment and re-infection in DDT exposed persons

Experimental study on concurrent infection with giardia lamblia and hymenolepis nana in mice

Many individuals are infected with more than one intestinal parasite. The presence of dual infection is a common incidence especially by parasites causing autoinfection or direct infection. Therefore, this work was planned to study the effect of concurrent infection with Giardia lamblia and Hymenolepis nana on the course of infection and local inflammatory reaction and immunity. Materials and methods: 170 Swiss albino mice, 18-20 gm each were used and divided into five groups; G [1] infected with G. lamblia [100, 000 cysts orally] only, G [2] infected with H. nana [500 shell free eggs orally] only, G [3] infected with G. lamblia then H. nana, G [4] infected with H. nana then G. lamblia and G [5] control non infected. Animals were sacrificed weekly after the last infection for 4 weeks. The intestines were processed for histopathological examination, stained with Alcian blue to examine the goblet cells and toluidine blue for identification of mast cells and IL-6 mRNA estimation by PCR technique in the small intestinal tissue homogenates. Two-hour cyst and trophozoite counts were performed weekly in Giardia groups and cysticercoids and adult H. nana were counted in Hymenolepis groups. There was a significant decrease in H. nana cystcercoid and adult worm counts in G [3]; and in G. lamblia cyst and trophozoite counts in G [4]. There was increased intensity of histopathological changes, lymphocytic infiltration in the lamina propria and hyperplasia of mast cells and goblet cells in Gs [3 and 4]. IL-6 mRNA was higher in the mixed infection than in the single infection groups. The presence of a preceding infection may produce a state of partial immunity against a second heterologus parasite and decrease the severity of infection by this parasite

Experimental schistosomal hepatitis: protective effect of coenzyme-Q10 against the state of oxidative stress

Schistosoma mansoni [S. mansoni] eggs trapped in the host liver elicit a chain of oxidative processes, where they not only trigger the production of reactive oxygen species, but also lead to alteration of the host antioxidant defense mechanisms. Such events may be, at least in part, responsible for the pathology and progression of fibrosis associated with schistosomal hepatitis. This study was designed to fulfill two aims; assessment of protective effect of the antioxidant Coenzyme-Q10 [Co-Q10] against the state of S. mansoni-induced oxidative stress in the liver, and evaluation of the potential role of Co-Q10 as an adjuvant to praziquantel [PZQ]. S. mansoni infected mice were divided into four main groups; group I: control non-treated group. Group II: received Co-Q10 after infection and was sacrificed 8 and 12 weeks post infection. Croup III: treated by single oral dose of PZQ 8 weeks post infection. Group IV: treated by single oral dose of PZQ 8 weeks post infection then was given Co-Q10 for four weeks. The oxidative stress and overall liver function were improved under Co-Q10 therapy as evidenced by significant reduction in oxidative stress markers, and preservation of antioxidant factors. Liver fibrosis was also reduced with a positive impact on liver function. Moreover, addition of Co-Q10 to PZQ therapy caused; significant reduction of liver egg load, significant improvement of the redox status, and lastly decreased liver fibrosis. From this study we concluded that Co-Q10: 1] ameliorated the oxidative stress status, 2] reduced the degree of liver fibrosis, and 3] enhanced the efficacy of classical therapy in experimental S. mansoni-induced hepatitis

Role Of alpha- chymotrypsin and colchicine as adjuvant therapy in experimental muscular trichinellosis : parasitological, biochemical and immunohistochemical study

Muscular trichinellosis is a crippling disease, and it is not satisfactorily treated by the anti-parasitic drug albendazole. Trichinella spiralis larvae can survive for long time in muscle phase by formation of fibrous [collagenous] capsule around it, for their protection from host immune system. Colchicine, is a well known antifibrotic that is used long time ago in different fibrotic diseases, and proved recently to be safe for use even in long durations. Also, alpha-chymotrypsin is one member of proteinase enzymes that were proved to cause degradation of extracellular matrix components. So, this study aimed to investigate the effect of adding these antifibrotic agents to albendazole during treatment of muscular trichinellosis. The study was performed on 175 albino mice comprising 7 equal groups 25 mice each. Mice from groups I to VI were infected by T.spiralis larvae orally [200larvae / mouse], group VII served as the healthy non infected group for comparison of biochemical and immunohistochemical results. Group II was treated by albendazole alone orally for three successive days, groups III, IV were given alpha-chymotrypsin intramuscularly and colchicine orally respectively, for four weeks. Groups V,VI were given combined therapy of albendazole and alpha-chymotrypsin and albendazole and colchicine respectively for four weeks. Assessment of results was achieved through; parasitological, biochemical and immunohistochemical studies. Total larval count was done to all studied infected groups, measurement of tissue markers of fibrosis'' muscle hydroxyproline and [MMP-2]'', and also immunohistochemical staining of collagen type IV and fibronectin was done to both infected groups and the non infected one for comparison. Statistical analysis was performed to determine differences between studied groups in different measured parameters. In groups treated with combination therapy [albendazole and alpha-chymotrypsin, ''group V'' and albendazole and colchicine'' group VI''], there was a marked reduction in total larval count, reduction of muscular hydroxyproline levels, elevation of muscular MMP-2 when compared to the group treated with albendazole alone ''group II'', the differences were found to be statistically significant [p<0.05]. At the same time, the differences in the previously mentioned parameters were proved to be non significant statistically between group V and group VI. There was also a decrease in staining intensity of collagen type IV and fibronectin in groups received the antifibrotics[groups III to VI] in comparison to both groups I and II and the, there was a statistical positive correlation between hydroxyproline biochemical mean value and staining intensity [p<0.05]. Addition of antifibrotic drugs [alpha- chymotrypsin and colchicine] as adjuvant therapy to antiparasitic drugs in treatment of muscular trichinellosis could be a beneficial measure to improve treatment outcome by decreasing both numbers of larvae in the muscle, and fibrous tissue formation, which form together the backbone of pathology and crippling to the patient