Trichinella spiralis Larval Extract as a Biological Anti-Tumor Therapy in a Murine Model of Ehrlich Solid Carcinoma.

Trichinella spiralis (T. spiralis) is an immunomodulating parasite that can adversely affect tumor growth and extend host lifespan. The aim of this study was to elucidate the mechanisms by which T. spiralis larval antigens achieve this effect using Ehrlich solid carcinoma (ESC) murine model. Assessment was done by histopathological and immunohistochemical analysis of caspase-3, TNF-α, Ki-67 and CD31. Additionally, Bcl2 and Bcl2-associated protein X (Bax) relative gene expression was assessed by molecular analysis for studying the effect of T. spiralis crude larval extract (CLE) antigen on tumor necrosis, apoptosis, cell proliferation and angiogenesis. We found that both T. spiralis infection and CLE caused a decrease in the areas of necrosis in ESC. Moreover, they led to increased apoptosis through activation of caspase-3, up-regulation of pro-apoptotic gene, Bax and down-regulation of anti-apoptotic gene, Bcl2. Also, T. spiralis infection and CLE diminished ESC proliferation, as evidenced by decreasing Ki-67. T. spiralis infection and CLE were able to suppress the development of ESC by inhibiting tumor proliferation, inducing apoptosis and decreasing tumor necrosis, with subsequent decrease in tumor metastasis. T. spiralis CLE antigen may be considered as a promising complementary immunotherapeutic agent in the treatment of cancer.

Lentinula edodes extract increases goblet cell number and Muc2 expression in an intestinal inflammatory model of Trichinella spiralis infection.

AHCC® is a standardized extract of cultured mushroom (Lentinula edodes) mycelia with a wide variety of therapeutic effects including anti-inflammatory, antitumor and antiviral effects. Trichinellosis, a food-borne parasitic zoonosis is caused by the nematode Trichinella spp. Infection with Trichinella is characterized by the induction of a Th1-type response at the beginning of the intestinal phase, followed by a dominant Th2-type response which is essential for parasite expulsion. The aim of this study was to evaluate the immunomodulatory effect of AHCC® in a murine model of Trichinella spiralis infection. Swiss CD1 mice were infected with T. spiralis larvae and treated with AHCC®. Standard treatment with albendazole (ABZ) was used as control in the assessment of parasite burden. The small intestine was taken out and the proximal segment was evaluated for several parameters: gene expression of immune and stress-reticulum mediators, histological damage score, goblet cell count and Mucin 2 (Muc2) gene expression. AHCC® modulated expression levels of both Th1 and Th2 cytokines and reduced histological damage score. In addition, AHCC® diminished the number of adults of T. spiralis in treated animals. AHCC® treatment anticipates T. spiralis expulsion and increases goblet cell number and Muc2 gene expression.

Sanguinarine has anthelmintic activity against the enteral and parenteral phases of trichinella infection in experimentally infected mice.

Trichinellosis is a zoonotic parasitic disease caused by Trichinella spiralis, and it is also a widely prevalent foodborne parasitic disease. At present, albendazole and benzimidazole are the most commonly used therapeutic drugs for the clinical treatment of trichinellosis, but they have many side effects. Sanguinarine is a benzophenanthridine alkaloid that has biological activity, such as antibacterial, antitumour and antiparasitic activities. Therefore, the present study aimed to evaluate the anti-Trichinella effect of sanguinarine in vivo and in vitro. The results showed that sanguinarine had a lethal effect on muscle larvae, adults and new-borne larvae in vitro. The damage to adults treated with sanguinarine was observed by scanning electron microscopy. Sanguinarine could significantly reduce the burden of worms in mice during the pre-adult, migrating larva and encysted larva stages. The ratio of intestinal villus to crypt (V/C) in mice treated with sanguinarine was significantly higher than that in non-treated control mice. Compared with the non-treated control group, the sanguinarine-treated group exhibited a significantly increased number of small intestine goblet cells. The level of reactive oxygen species (ROS) in the serum of mice treated with sanguinarine was significantly higher than that of the control group mice in the pre-adult and encysted larva stages. This study suggests that sanguinarine is a potential drug against trichinellosis.

Isolation of a Novel Flavanonol and an Alkylresorcinol with Highly Potent Anti-Trypanosomal Activity from Libyan propolis.

Twelve propolis samples from different parts of Libya were investigated for their phytochemical constituents. Ethanol extracts of the samples and some purified compounds were tested against Trypanosoma brucei, Plasmodium falciparum and against two helminth species, Trichinella spiralis and Caenorhabditis elegans, showing various degrees of activity. Fourteen compounds were isolated from the propolis samples, including a novel compound Taxifolin-3-acetyl-4'-methyl ether (4), a flavanonol derivative. The crude extracts showed moderate activity against T. spiralis and C. elegans, while the purified compounds had low activity against P. falciparum. Anti-trypanosomal activity (EC50 = 0.7 µg/mL) was exhibited by a fraction containing a cardol identified as bilobol (10) and this fraction had no effect on Human Foreskin Fibroblasts (HFF), even at 2.0 mg/mL, thus demonstrating excellent selectivity. A metabolomics study was used to explore the mechanism of action of the fraction and it revealed significant disturbances in trypanosomal phospholipid metabolism, especially the formation of choline phospholipids. We conclude that a potent and highly selective new trypanocide may be present in the fraction.

Killing the muscular larvae of Trichinella spiralis and the anti-fibrotic effect of the combination of Wortmannilatone F and recombinant G31P in a murine model of trichinellosis.

Although trichinosis is one of the global food-borne parasitic diseases and is considered an emerging/re-emerging disease that has been reported in 66 countries, the drugs for its prevention and treatment have not been thoroughly investigated. Wortmannilactone F (WF) has been reported as a blocker of the helminth mitochondria respiratory chain by inhibiting NADH-fumarate reductase in the mitochondrial inner membrane. CXCL8 (3-73) K11R/G31 P(G31 P) has been reported as a CXCL8 analogue that has the affinity to CXCR1 and CXCR2. Male BALB/c mice were orally fed with 150 infective Trichinella spiralis (T. spiralis) larvae. Then, T. spiralis-infected mice were treated with WF and G31 P. The number and morphological analysis of encapsulated T. spiralis, collagen fiber accumulation, and the expression of angiogenic factors were investigated. WF and G31 P dramatically decreased the numbers of encapsulation, decreased collagen fibers, and suppressed angiogenesis. These findings indicate that the combination of WF and G31 P is a potential therapeutic strategy of Trichinellosis.

Effect of two recombinant Trichinella spiralis serine protease inhibitors on TNBS-induced experimental colitis of mice.

Inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease (CD), is a chronic autoimmune disease. Parasitic infections and their products have been shown to have protective effects on autoimmune diseases, including IBD. In this experiment, 96 male BALB/c mice aged 6-8 weeks were divided randomly into two large groups: prevention and therapy. The changes in the various indicators of colitis were detected to demonstrate that Trichinella spiralis serine protease inhibitors can relieve the inflammatory severity of 2,4,6-trinitrobenzenesulphonic acid solution (TNBS)-induced colitis and to explore possible immunological mechanisms. Results showed that the disease activity index (DAI) score, myeloperoxidase (MPO) activity, macroscopic and microscopic damage degrees of colon all decreased significantly, interferon (IFN)-γ expression decreased, interleukin (IL)-4 expression increased, nuclear factor kappa B (NF)-κB expression decreased and the percentage of CD4+ CD25+ forkhead box protein 3 (FoxP3+ ) regulatory T cells (Treg ) cells in the spleen. MLN increased significantly compared to the phosphate-buffered saline (PBS)/2,4,6-trinitrobenzenesulphonic acid solution (TNB) group. We found the same results with the T. spiralis Kazal-type serine protease inhibitors (TsKaSPI)+TNBS and TsAdSPI+TNBS groups in the large prevention group and the large therapy group, compared to the TNBS+PBS group with the TNBS+TsKaSPI and TNBS+TsAdSPI groups. Immunization with TsKaSPI and TsAdSPI on the CD models showed an intervention effect, possibly because TsKaSPI and TsAdSPI induced a T helper type 2 (Th2)-type immune response and balanced the TNBS-induced Th1-type immune response.

Biodegradable Chitosan Decreases the Immune Response to Trichinella spiralis in Mice.

The purpose of this study was to evaluate the potential of chitosan units released during natural degradation of the polymer to activate the immune system against T. spiralis infection. High molecular weight chitosan was injected intraperitoneally into C57BL/6 mice. Flow cytometry and cytokine concentration, measured by ELISA, were used to characterize peritoneal cell populations during T. spiralis infection. The strong chemo-attractive properties of chitosan caused considerable infiltration into the peritoneal cavity of CD11b⁺ cells, with reduced expression of MHC class II, CD80, CD86, Dectin-1 or CD23 receptors in comparison to T. spiralis-infected mice. After prolonged chitosan biodegradation, cell populations expressing IL-4R, MR and Dectin-1 receptors were found to coexist with elevated IL-6, IL-10, TGF-ß and IgA production. IgA cross-reacted with T. spiralis antigen and chitosan. It was found that chitosan treatment attracted immune cells with low activity, which resulted in the number of nematodes increasing. The glucosamine and N-acetyl-D-glucosamine residues were recognized by wheat germ agglutinin (WGA) lectin and therefore any biodegradable chitosan units may actively downregulate the immune response to the parasite. The findings are relevant for both people and animals treated with chitosan preparations.

Atorvastatin and metformin administration modulates experimental Trichinella spiralis infection.

The host-parasite interaction can be altered by the changes in the host environment that may be or may not be in favor of successful invasion by the nematode parasite Trichinella spiralis. Metformin and atorvastatin are applied on a wide scale, to the degree that they could be considered as part of the host biochemical environment that can affect the parasite. Therefore, this study aimed to investigate the impact of alteration of the host's biochemical environment by these commonly used drugs upon the course of T. spiralis infection. Mice were divided into three groups: (1) received atorvastatin, (2) received metformin, and (3) untreated, then after one week, animals were infected with T. spiralis. The treatment continued until the end of the experiment. From each group, small intestines and muscles were removed for histopathological, immunohistochemical, and biochemical analyses as well as total muscle larval counts. We found that the oxidative stress and the expression of vascular endothelial growth factor (VEGF) in the muscles were significantly reduced in both drug-receiving groups, while the total larval counts in muscles were only significantly reduced in atorvastatin-receiving group as compared to the infected control group. Moreover, marked reduction in the inflammatory cellular infiltration, cyclooxygenase-2 (COX-2) expression, and oxidative stress was noted in the small intestines of the treated groups as compared to the infected control group. In conclusion, this study provides many insights into the different biochemical changes in the host that the parasite has to face. Moreover, the anti-inflammatory and anti-angiogenic effects should be taken into consideration when treating infections in patients on therapy with atorvastatin or metformin.

Effect of myrrh and thyme on Trichinella spiralisenteral and parenteral phases with inducible nitric oxide expression in mice

Trichinellosis is a serious disease with no satisfactory treatment. We aimed to assess the effect of myrrh (Commiphora molmol) and, for the first time, thyme (Thymus vulgaris L.) against enteral and encysted (parenteral) phases of Trichinella spiralis in mice compared with albendazole, and detect their effect on inducible nitric oxide synthase (iNOS) expression. Oral administration of 500 mg/kg of myrrh and thyme led to adult reduction (90.9%, 79.4%), while 1,000 mg/kg led to larvae reduction (79.6%, 71.3%), respectively. Administration of 50 mg/kg of albendazole resulted in adult and larvae reduction (94.2%, 90.9%). Positive immunostaining of inflammatory cells infiltrating intestinal mucosa and submucosa of all treated groups was detected. Myrrh-treated mice showed the highest iNOS expression followed by albendazole, then thyme. On the other hand, both myrrh and thyme-treated groups showed stronger iNOS expression of inflammatory cells infiltrating and surrounding encapsulated T. spiralis larvae than albendazole treated group. In conclusion, myrrh and thyme extracts are highly effective against both phases of T. spiralis and showed strong iNOS expressions, especially myrrh which could be a promising alternative drug. This experiment provides a basis for further exploration of this plant by isolation and retesting the active principles of both extracts against different stages of T. spiralis.

[In vitro killing of Trichinella spiralis muscle larvae by exogenous nitric oxide from SNP].

OBJECTIVE: To study the lethal effect of exogenous nitric oxide donor sodium nitroprusside (SNP) on the muscle larvae of Trichinella spiralis in vitro cultivation. METHODS: T. spiralis muscle larvae isolated from the infected BALB/c mice were formulated into a 1,000 larva/ml suspension with RPMI 1640 medium, and 0.1 ml suspension per orifice was cultured with SNP at 37°C in a humidified 5% CO2 atmosphere. The final concentrations of SNP were 0.02, 0.05, 0.10, 0.20, 0.50 and 1.00 mmol/L, respectively, and then the experiments were divided into 5 groups:1.00 mmol/L SNP (control group, Group A), 0.15 mmol/L FeSO4+ 1.00 mmol/L SNP (Group B), 1.00 mmol/L L-cysteine + 1.00 mmol/L SNP (Group C), 0.15 mmol/L FeSO4+ 1.00 mmol/L L-cysteine + 1.00 mmol/L SNP (Group D) and 0.15 mmol/L Hemoglobin + 1.00 mmol/L SNP (Group E). All the groups were incubated with T. spiralis muscle larvae in RPMI 1640 medium. The survivability of the muscle larvae was observed by steromicroscope and the differences of inhibition ratio among these groups were analyzed 4 d after the incubation. Results SNP 0.02 mmol/L was not cytotoxic to the muscle larvae with an inhibition of (5.50 ± 1.80) %. The mortality rates of SNP 0.05, 0.10, 0.20, 0.50, 1.00 mmol/L groups were (20.19±2.71)%, (29.21±2.12)%, (41.81±2.03)%, (47.85±3.79)%, (60.98±5.19)%, respectively, significantly higher than that of the control group[(4.93±0.25) %, all P < 0.051]. There was a positive liner correlation between the mortality of muscle larvae and SNP concentrations in the range of 0.02-1.00 mmol/L. Next, Group A, B, C, D and E led to the mortalities from (60.98±5.19)% to (49.48±1.34)%, (47.29±2.79)%, (26.28±1.37)%, (17.93±3.49)%, respectively, and all the differences between Group A and the other four groups were statistically significant (all P < 0.05). CONCLUSIONS: Exogenous nitric oxide released from SNP can kill the muscle larvae of T. spiralis. However, hemoglobin, L-cysteine, and FeSO4 can reverse the lethal effect on the parasites. The best inhibitor was hemoglobin.

[In vitro killing of adult Trichinella spiralis by exogenous nitric oxide].

OBJECTIVE: To investigate the lethal effect of exogenous nitric oxide on adult worms of Trichinella spiralis in vitro. METHODS: Adult worms of T. spiralis isolated from the small intestine of Trichinella-infected BALB/c mice were cultured in RPMI 1640 medium with sodium nitroprusside (SNP) in different final concentration of 0, 0.02, 0.05, 0.10, 0.20, 0.50, and 1.00 mmol/L, 1.00 mmol/L SNP+0.15 mmol/L hemoglobin (Hb), 1.00 mmol/L SNP+0.15 mmol/L FeSO4, 1.00 mmol/L SNP+1.00 mmol/L L-cysteine (L-cyst), 1.00 mmol/L SNP+0.15 mmol/L FeSO4 +1.00 mmol/L L-cyst, respectively, and incubated at 37 degrees C in a humidified 5% CO2 atmosphere. On the 4th day after incubation, the adult worms were stained with safranin, and observed under light microscope. The worm mortality in the groups was analyzed. RESULTS: Under concentration of 0.02 and 0.05 mmol/L, SNP was not cytotoxic to adult T. spiralis with an inhibition of (1.4 +/- 1.2)% and (3.2 +/- 1.0)%, respectively. The worm mortality in the groups of SNP 0.10, 0.20, 0.50, and 1.00 mmol/L was (9.9 +/- 1.8)%, (37.7 +/- 2.5)%, (50.1 +/- 3.5)%, and (80.8 +/- 1.1)%, respectively, significantly higher than that of negative control group [(1.9 +/- 0.2)%, P < 0.05]. There was a positive linear correlation between the worm mortality and SNP concentration in the range of 0.02-1.00 mmol/L. Combination of hemoglobin, L-cyst, FeSO4 and FeSO4+L-cyst with 1.00 mmol/L SNP led to a decrease of the mortality from (80.8 +/- 1.1)% to (56.5 +/- 3.7)%, (69.8 +/- 2.3)%, (74.8 +/- 2.4)%, (72.7 +/- 5.6)%, respectively. CONCLUSION: Exogenous nitric oxide released from SNP can kill adult worms of Trichinella spiralis. However, hemoglobin and L-cysteine+FeSO4 can reverse its lethal effect on the parasites.

Sex steroids effects on the molting process of the helminth human parasite Trichinella spiralis.

We evaluated the in vitro effects of estradiol, progesterone, and testosterone on the molting process, which is the initial and crucial step in the development of the muscular larvae (ML or L1) to adult worm. Testosterone had no significative effect on the molting rate of the parasite, however, progesterone decreased the molting rate about a 50% in a concentration- and time-independent pattern, while estradiol had a slight effect (10%). The gene expression of caveolin-1, a specific gene used as a marker of parasite development, showed that progesterone and estradiol downregulated its expression, while protein expression was unaffected. By using flow citometry, a possible protein that is recognized by a commercial antiprogesterone receptor antibody was detected. These findings may have strong implications in the host-parasite coevolution, in the sex-associated susceptibility to this infection and could point out to possibilities to use antihormones to inhibit parasite development.

Parasite challenge as host resistance models for immunotoxicity testing.

Identification of potentially immunosuppressive compounds typically involves assessing a combination of observational endpoints as surrogates for functional endpoints and functional endpoints as surrogates for resistance to infectious or neoplastic disease. Host resistance assays are considered to be the "gold standard" against which suppression of immune function at the molecular or cellular level can be judged, because resistance to infection, regardless of the actual pathogen, involves multiple pathways of effector function to neutralize or eliminate pathogens. Resistance to infection with the parasitic nematode Trichinella spiralis has been used to assess immune function following exposure to a variety of immunotoxicants at the whole animal level. The various immunological mechanisms that are responsible for resistance to different phases of the life cycle are well documented, as are the effects of immunosuppression on the outcome of infection. This chapter describes methods to assess elimination of adult parasites from the small intestine, body burdens of larvae, as well as antibody responses and lymphocyte responses to parasite antigens.

[Diagnosis and treatment of trichinellosis].

Lack of specific symptoms and signs makes clinical diagnosis of trichinellosis difficult. Epidemiological information is important, such as a history of ingesting raw or undercooked meat. An outbreak can be traced to a group of people dining together. Usual manifestations include abdominal pain or diarrhea with general discomfort in the enteric stage, and fever, eyelid or facial edema, muscle pain in acute stage. Complications, such as myocarditis, pneumonia, encephalitis, may develop in severe cases. Eosinophilia appears between 2 and 5 weeks after infection. Enzyme-linked immunosorbent assay (ELISA) using the excretory-secretory (ES) antigens of the muscle larvae or synthetic tyvelose as antigen is sensitive and specific, the serological method ,of choice as a screening test. Western blotting is needed to confirm the positive ELISA. Definitive diagnosis depends on the finding of larvae in a muscle biopsy specimen. Albendazole is the drug of choice for its treatment, 20-30 mg/(kg x d), two times daily for 5-7 days. Glucocorticosteroids are given only to severe cases and always be used in combination with albendazole, since they could prolong the intestinal phase of the infection and increase the muscle larval burdens.

In vitro and in vivo effects of progesterone on Trichinella spiralis newborn larvae.

We have previously demonstrated that during pregnancy there exists an increased parasiticide activity against Trichinella spiralis newborn larvae (NBL) in infected rats. In this work we analysed the contribution of peritoneal cells from noninfected pregnant rats to the mortality of the NBL in cytotoxicity assays, and evaluated the role of progesterone in this effector mechanism. Our findings suggest that progesterone can induce activation of effector peritoneal cells to destroy the NBL in a rapid and antibody-independent manner. The administration of progesterone to ovariectomized rats also led to a significant decrease in the parasite load of the animals, thus demonstrating that progesterone induces the increase of the parasiticide activity of the leukocytes involved in the mechanisms of NBL death.

Anthelminthic and antiallergic activities of Mangifera indica L. stem bark components Vimang and mangiferin.

This study investigated the antiallergic and anthelmintic properties of Vimang (an aqueous extract of Mangifera indica family stem bark) and mangiferin (the major polyphenol present in Vimang) administered orally to mice experimentally infected with the nematode, Trichinella spiralis. Treatment with Vimang or mangiferin (500 or 50 mg per kg body weight per day, respectively) throughout the parasite life cycle led to a significant decline in the number of parasite larvae encysted in the musculature; however, neither treatment was effective against adults in the gut. Treatment with Vimang or mangiferin likewise led to a significant decline in serum levels of specific anti-Trichinella IgE, throughout the parasite life cycle. Finally, oral treatment of rats with Vimang or mangiferin, daily for 50 days, inhibited mast cell degranulation as evaluated by the passive cutaneous anaphylaxis test (sensitization with infected mouse serum with a high IgE titre, then stimulation with the cytosolic fraction of T. spiralis muscle larvae). Since IgE plays a key role in the pathogenesis of allergic diseases, these results suggest that Vimang and mangiferin may be useful in the treatment of diseases of this type.

Cystatin capture-dot-enzyme-linked immunosorbent assay for immunodiagnosis and assessment of cure of experimental trichinellosis in mice.

Cystatin capture dot enzyme-linked immunosorbent assay (CC-dot ELISA) was evaluated as a new version of ELISA for diagnosis of trichinellosis by the detection of anti-Trichinella spiralis cysteine proteinase (CyP) IgG, using nitrocellulose membrane sensitized with cystatin as a capture reagent for CyP from T. spiralis muscle larvae excretory secretory products (ESP) without purification, compared to the detection of anti-T. spiralis IgG by conventional (conv.) ELISA, using whole ESP. Experimentally infected mice with light (100 larvae/mouse) and heavy (300 larvae/mouse) infections by T. spiralis larvae at 7, 14, 21 and 56 days post infection, and after flubendazole treatment were examined. As early as one week post infection CC-dot ELISA gave high positive rates of 86.6% and 100% in light and heavy infections, respectively, in contrast to negative results by conv. ELISA. CC-dot ELISA showed in light and heavy trichinellosis a higher efficiency in comparison to conv. ELISA (97.7% versus 67.7% and 98.8% versus 80%, respectively) and a higher overall sensitivity (96.6% versus 55% and 98.3% versus 73.3%, respectively). No cross reactions with sera of other parasitic infected or non infected control mice were recorded by CC-dot ELISA giving 100% specificity compared to 93.3% by conv. ELISA. After treatment, CC-dot ELISA gave positive results only in uncured mice with remaining muscle larvae, while conv. ELISA was positive in mice with and without remaining muscle larvae. CC-dot ELISA used lower quantities of antigen, was performed at room temperature, and read by naked eye in less than 2.5 hours.

Failure of mebendazole in the treatment of humans with Trichinella spiralis infection at the stage of encapsulating larvae.

Trichinella spiralis larvae infective for laboratory mice were collected from muscle biopsies performed at different times (from 1 day to 16 months) following the end of treatment, indicating the failure of mebendazole to kill Trichinella parasites when they are encapsulating in muscles.

Modulation by Anapsos (Polypodium leucotomos extract) of the antibody responses against the nematode parasite Trichinella spiralis.

The immunomodulant effects of Anapsos, an extract of the naturally occurring fern Polypodium leucotomos was assessed in Balb/c mice immunized with a crude soluble extract (CSE) of Trichinella spiralis L1 larvae. Treatment from day 10 to 1 prior to immunization caused a significant reduction (p < 0.05) in total antibody levels (IgG + M) that was evident from week 2 onwards. Suppression of the IgG1 response was transient, as serum levels were significantly (p < 0. 01) decreased in treated animals during weeks 2 and 3 post-immunization, afterwards increasing to values similar to those in the control group. An opposite pattern was observed in the IgG2a and IgG 2b profiles where, following a brief increase in weeks 3 and 1, respectively, the values fell below those of the control and remained for the whole observation. Anapsos potentiates the IgG3 response against T. spiralis CSE. Deglycosylation of the CSE used in the ELISA assay significantly reduces the IgG3 recognition capacity in both control and treated mice. This treatment did not affect the time-course of an intestinal infection by T. spiralis.