In vivo treatment with nitazoxanide induces anaerobic metabolism in experimental intraperitoneal cysticercosis

In vitro metabolic stress induced by nitazoxanide and flubendazole combination in Taenia crassiceps cysticerci

Taenia crassiceps is often used as experimental model for T. solium cysticercosis studies. Currently cysticercosis antiparasitic treatment is based on albendazole and praziquantel which may present side effects and parasitic resistance. The search for other antiparasitic drugs is necessary. Nitazoxanide (NTZ) and flubendazole (FLB) are broad spectrum antiparasitic drugs that present anti-cysticercosis effect. Metabolic analyses help to determine the impact of these drugs on parasites. The aim of this study was to determine the impact on the production and excretion of organic metabolites in T. crassiceps cysticerci after in vitro exposure to NTZ and FLB, isolated or in combination. T. crassiceps cysticerci were culture in RPMI medium and exposed to 10μg/mL of NTZ, 10μg/mL of FLB or 10μg/mL of NTZ +10μg/mL of FLB. 24h after exposure, the parasites were chromatographic analyzed to determine the impact of these drugs on glycolysis, homolactic fermentation, tricarboxylic acid cycle, fatty acids oxidation and proteins catabolism. It was possible to determine that the drugs combination induced greater metabolic impact on cysticerci in comparison to the isolated drugs exposure. The drugs combination induced gluconeogenesis, metabolic acidosis, increase in tricarboxylic acid cycle and in proteins catabolism. While the NTZ isolated exposure induced metabolic acidosis and protein catabolism and the FLB isolate exposure induced gluconeogenesis and protein catabolism. These results show that the combination of drugs with different modes of action increase the antiparasitic effect and may be indicated as alternative cysticercosis treatments.

Intraperitoneal and intracranial experimental cysticercosis present different metabolic preferences after treatment with isolated or combined albendazole and nitazoxanide

Cysticercosis is a zoonotic public health issue especially severe when the parasite is in the central nervous system although it may be found all over the human organism. Taenia crassiceps cysticerci inoculated in mice is the experimental model used to study cysticercosis. The most used cysticercosis treatment is with albendazole (ABZ). Nitazoxanide (NTZ) has been experimentally tested against this parasite. Metabolic analysis has been used to determine drugs impact on the parasite. The aim of this study was to determine the in vivo metabolic impact of the ABZ-NTZ combination in T. crassiceps cysticerci inoculated in mice peritoneal and intracranial cavities. Mice were experimentally inoculated with T. crassiceps cysticerci in the intraperitoneal cavity or in the intracranial one. Thirty days after the infection they were treated with NaCl 0.9% (control group), 50 mg/kg of ABZ, 50 mg/kg of NTZ or 50 mg/kg of NTZ and ABZ (ABZ/NTZ combination). 24 h after treatment the animals were euthanized and the cysticerci analyzed through high performance chromatography and spectrophotometry in order to detect the glycolytic, mitochondrial and protein catabolism pathways. The intracranial parasites used more intensely the homolactic fermentation while the intraperitoneal ones presented a greater use of the mitochondrial pathways and protein catabolism. Regarding the glycolytic pathways, it was possible to observe a significant impact induced by the drugs used, both isolated or in combination. It was possible to detect an increase in the fumarate reductase pathway after the drugs exposure and no impact in the protein's catabolism. Therefore, the cysticerci showed different uses of metabolic pathways regarding the site of inoculation due to the availability of nutrients inherent of each environment. This study showed the parasite metabolic resilience and capability of use of different biochemical pathways in order to ensure survival in spite of a hostile environment.

In Vivo Treatment with the Combination of Nitazoxanide and Flubendazole Induces Gluconeogenesis and Protein Catabolism in Taenia crassiceps cysticerci

PURPOSE

Cysticercosis is the presence of Taenia solium larvae in humans or swines tissues. It is a public health problem related to bad hygienic habits and consumption of infected pork. T. crassiceps is a widely used cysticercosis experimental model. The combination of two effective drugs such as nitazoxanide (NTZ) and flubendazole (FBZ) may potentialize their effect. The aim of this study was to use biochemical analysis to determine the metabolic impact of the combination of NTZ and FBZ on cysticerci inoculated intraperitoneally in mice.

METHODS

Balb/c mice intraperitoneally infected with T. crassiceps cysticerci received a single oral dose NTZ/FBZ (50 mg/kg). 24 h after the treatment the cysticerci were removed, frozen and analyzed by high performance liquid chromatography regarding the detection of the following metabolic pathways: glycolysis, gluconeogenesis, homolactic fermentation, tricarboxylic acid cycle, proteins catabolism and fatty acids oxidation.

RESULTS

The treatment with the drugs combination induced a statistically significant increase in gluconeogenesis and in protein catabolism when compared to the control groups.

CONCLUSION

The drugs combination is potentialized and capable of causing greater metabolic stress than the separate treatment with NTZ or FBZ, showing its potential for an alternative cysticercosis treatment.

Nanodelivery of nitazoxanide: impact on the metabolism of Taenia crassiceps cysticerci intracranially inoculated in mice

Aim: To formulate nanocapsules and nanoemulsions of nitazoxanide (NTZ) and evaluate the metabolic effect on Taenia crassiceps cysticerci inoculated intracranially into mice. Materials & methods: NTZ nanosystems were formulated through solvent diffusion methodology. These nanoformulations were administered perorally and their impact on glycolysis, the tricarboxylic acid cycle and fatty acid metabolism in T. crassiceps cysticerci was investigated. Results: Gluconeogenesis and protein catabolism were significantly increased by the nanoformulations when compared with the control group and the NTZ-treated group. All the other metabolic pathways were inhibited by the nanoformulation treatments. Conclusion: The remarkable metabolic modifications that occur in this in vivo model through the application of these developed nanosystems confirm their capability to deliver NTZ into targeted tissues.

Metabolic effects of anthelminthic drugs in the larval stage of the cestode Taenia crassiceps, cysticercosis experimental model - A review

Taenia crassiceps is an experimental model used for cysticercosis studies and has suffered metabolic analyzes regarding the effect of anthelminthic drugs. The metabolic analyses are useful tools to determine the drugs mode of action and the parasite`s survival mechanisms. The energetic pathways are good candidates for this kind of approach as they are essential for the parasite`s survival and adaptation to the environment. In this review we discuss the anthelminthic drugs mode of action and its metabolic impact on Taenia crassiceps cysticerci.

In vitro nitazoxanide exposure affects energetic metabolism of Taenia crassiceps

Nitazoxanide (NTZ) is a broad-spectrum drug used in intestinal infections, but still poorly explored in the treatment of parasitic tissular infections. This study aimed to evaluate the in vitro responses of the energetic metabolism of T. crassiceps cysticerci induced by NTZ. The organic acids of the tricarboxylic acid cycle, products derived from fatty acids oxidation and protein catabolism were analyzed. These acids were quantified after 24 h of in vitro exposure to different NTZ concentrations. A positive control group was performed with albendazole sulfoxide (ABZSO). The significant alterations in citrate, fumarate and malate concentrations showed the NTZ influence in the tricarboxylic acid (TCA) cycle. The non-detection of acetate confirmed that the main mode of action of NTZ is effective against T. crassiceps cysticerci. The statistical differences in fumarate, urea and beta-hydroxybutyrate concentrations showed the NTZ effect on protein catabolism and fatty acid oxidation. Therefore, the main energetic pathways such as the TCA cycle, protein catabolism and fatty acids oxidation were altered after in vitro NTZ exposure. In conclusion, NTZ induced a significant metabolic stress in the parasite indicating that it may be used as an alternative therapeutic choice for cysticercosis treatment. The use of metabolic approaches to establish comparisons between anti parasitic drugs mode of actions is proposed.

Partial inhibition of the main energetic pathways and its metabolic consequences after in vivo treatment with benzimidazole derivatives in experimental neurocysticercosis

Benzimidazole derivatives such as albendazole (ABZ) and mebendazole are important molecules used in helminthic treatment. Neurocysticercosis is the main cause of acquired epilepsy throughout the world and is currently treated with ABZ. New molecules have been studied in order to aid in the treatment of this neglected tropical disease, among them RCB15 and RCB20. The aim of this study was to evaluate the metabolic impact of RCB15 and RCB20 on Taenia crassiceps cysticerci intracranially inoculated in Balb/c mice. Thirty days after the inoculation the mice were treated with 50 mg kg−1 of RCB15, RCB20, ABZ or NaCl 0.9%. The euthanasia and cysticerci removal were performed 24 h after the treatment. The cysticerci were analysed through high performance liquid chromatography. After the treatments, there was an impairment in the main energetic pathways such as glycolytic pathway, homolactic fermentation or in mitochondrion energy production detected through the decrease in pyruvate, lactate, oxaloacetate, malate and fumarate concentrations. This induced the parasite to resort to alternative energetic pathways such as proteins catabolism, propionate fermentation and fatty acids oxidation. Therefore, benzimidazole derivatives are a promising alternative to ABZ use as they also reach the brain tissue and induce a metabolic stress in the cysticerci.

Oral nitazoxanide treatment of experimental neurocysticercosis induces gluconeogenesis in Taenia crassiceps cysticerci

Neurocysticercosis is the most frequent helminthiasis of the central nervous system and is caused by the presence of Taenia solium cysticerci. Nitazoxanide (NTZ) is an antifolate containing the pyrrolopyrimidine-based nucleus that exerts its antiprotozoal activity due to interference with the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme which is essential to anaerobic energy metabolism. The aim of this work was to determine the effect of NTZ on the energetic metabolism of Taenia crassiceps cysticerci intracranially inoculated BALB /c mice. The infected animals were treated with a single oral dose of NTZ 30 days after the inoculation. Analysis of the organic acids was performed through high performance liquid chromatography. Glucose was detected only in the treated groups, alongside with a significant decrease in lactate, pyruvate and oxaloacetate concentrations which indicate an increase in gluconeogenesis. The non-detection of alpha-ketoglutarate indicated the use of the fumarate reductase pathway in all groups. It was possible to confirm the drugs mode of action due to the non-detection of acetate in the treated groups. There was an increase in the fatty acids oxidation. Therefore it was possible to observe that NTZ induces gluconeogenesis as well as the increase of alternative energetic pathways such as fatty acids oxidation in T. crassiceps cysticerci.