Punica granatum and amygdalin extracts plus cobalamin combined with albendazole reduce larval burden and myositis in experimental trichinosis / Extratos de Punica granatum e amígdalina mais cobalamina combinado com albendazol reduzem a carga larvar e a miosite na triquinose experimental

Abstract Trichinellosis is a zoonosis results from eating raw or semi-cooked meat of infected animals. Medicinal plants have been used lately as alternatives and/or combined therapies to resolve some drawbacks of the current regimens. This work analyzed the effect of albendazole monotherapy on Trichinella spiralis experimental infection (group A), in comparison to P. granatum and amygdalin extracts +cobalamin (group B), plus its combination with albendazole (group C). The study revealed that the extracts alone or combined with albendazole had an inferior effect to albendazole monotherapy regarding number of adult worms (40.83 ±3.82, 18.67 ±1.86 and 16.83 ±2.32, respectively). However, their effect was more obvious in muscle phase combined with albendazole, achieving the lower number of larvae/mL tissue homogenate (22.33 ±3.27 in comparison to 39.67 ±2.58 achieved by albendazole monotherapy). The extracts exerted a significant immunomodulatory effect by reducing the local CD4+ expression in the intestine as well as in muscle phase (1.15 ±0.25 and 3.80 ±0.65 in comparison to 4.97 ±0.37 and 12.20 ±0.87 with albendazole monotherapy, respectively). So, these extracts improved the therapeutic efficacy of albendazole, specifically in muscle phase and counteracted the inflammatory reaction caused by albendazole monotherapy, thus extensively alleviating the resulting myositis.

Resumo Trichinellosis é uma zoonose resultante da ingestão de carne crua ou semicozida de animais infectados. As plantas medicinais têm sido usadas, ultimamente, como alternativas e/ou terapias combinadas, para resolver algumas desvantagens dos regimes atuais. Este trabalho analisou o efeito da monoterapia albendazole na infecção experimental por Trichinella spiralis (grupo A), em comparação com extratos de P. granatum e amígdalina +cobalamina (grupo B), além de sua combinação com albendazol (grupo C). O estudo revelou que os extratos sozinho ou combinado com albendazol teve efeito inferior à monoterapia albendazol em relação ao número de vermes adultos (40,83 ±3,82, 18,67 ±1,86 e 16,83 ±2,32, respectivamente). No entanto, seu efeito foi mais óbvio na fase muscular combinado com o albendazol, alcançando o menor número de larvas/mL homogeneizado de tecido (22,33 ±3,27 em comparação com 39,67 ±2,58 obtidos pela monoterapia albendazol). Os extratos exerceram um efeito imunomodulatório significativo, ao reduzir a expressão local CD4+ no intestino, bem como na fase muscular (1,15 ±0,25 e 3,80 ±0,65 em comparação com 4,97 ±0,37 e 12,20 ±0,87 com monoterapia albendazol, respectivamente). Assim, esses extratos melhoraram a eficácia terapêutica do albendazol, especificamente na fase muscular e neutralizaram a reação inflamatória causada pela monoterapia albendazol, aliviando extensivamente a miosite resultante.

Activation and Recruitment of Regulatory T Cells via Chemokine Receptor Activation in Trichinella spiralis-Infected Mice

As most infections by the helminth parasite elicit the recruitment of CD4+CD25+Foxp3+ T (T(reg)) cells, many scientists have suggested that these cells could be used for the treatment of immune-mediated inflammation and associated diseases. In order to investigate the distribution and alteration of activated T(reg) cells, we compared the expression levels of T(reg) cell activation markers in the ileum and gastrocnemius tissues 1, 2, and 4 weeks after infection. The number of T(reg) cells was monitored using GFP-coded Foxp3 transgenic mice. In mice at 1 week after Trichinella spiralis infection, the number of activated T(reg) cells was higher than in the control group. In mice at 2 weeks after infection, there was a significant increase in the number of cells expressing Foxp3 and CTLA-4 when compared to the control group and mice at 1 week after infection. At 4 weeks after infection, T. spiralis was easily identifiable in nurse cells in mouse muscles. In the intestine, the expression of Gzmb and Klrg1 decreased over time and that of Capg remained unchanged for the first and second week, then decreased in the 4th week. However, in the muscles, the expression of most chemokine genes was increased due to T. spiralis infection, in particular the expression levels of Gzmb, OX40, and CTLA-4 increased until week 4. In addition, increased gene expression of all chemokine receptors in muscle, CXCR3, CCR4, CCR5, CCR9, and CCR10, was observed up until the 4th week. In conclusion, various chemokine receptors showed increased expressions combined with recruitment of T(reg) cells in the muscle tissue.

Toll-Like Receptor Gene Expression during Trichinella spiralis Infection

In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T (T(reg)) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and T(reg) cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/TIRAP-/- MEF cells, and quite substantially decreased in TRIF-/- MEF cells. In contrast, IL-10 and TGF-beta expression levels were not elevated in MyD88/TIRAP-/- MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and T(reg) cell mediated immune responses, although additional data are needed to convincingly prove this observation.