Titanium Dioxide Nanoparticle (TiO2 NP) Induces Toxic Effects on LA-9 Mouse Fibroblast Cell Line.

BACKGROUND/AIMS: Titanium dioxide nanoparticles (TiO2 NPs) are extensively applied in the industry due to their photocatalytic potential, low cost, and considerably low toxicity. However, new unrelated physicochemical properties and the wide use of nanoparticles brought concern about their toxic effects. Thereby, we evaluated the cytotoxicity of a TiO2 NP composed of anatase and functionalized with sodium carboxylate ligands in a murine fibroblast cell line (LA-9). METHODS: Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), and ATR-FTIR spectroscopy were applied to determine nanoparticle physicochemical properties. The cell viability (MTT assay) and clonogenic survival were analyzed in fibroblasts exposed to TiO2 NP (50, 150, and 250 µg/mL) after 24h. Moreover, oxidative stress, proinflammatory state, and apoptosis were evaluated after 24h. RESULTS: TiO2 NP characterization showed an increased hydrodynamic size (3.57 to 7.62 nm) due to solvent composition and a heterogeneity dispersion in water and cell culture media. Also, we observed a zeta potential increased from -20 to -11 mV in function of protein adsorption. TiO2 NP reduced fibroblast cell viability and induced ROS production at the highest concentrations (150 and 250 µg/mL). Moreover, TiO2 NP reduced the fibroblasts clonogenic survival at the highest concentration (250 µg/mL) on the 7th day after the 24h exposure. Nevertheless, TiO2 NP did not affect the fibroblast proinflammatory cytokines (IL-6 and TNF) secretion at any condition. Early and late apoptotic fibroblast cells were detected only at 150 µg/mL TiO2 NP after 24h. CONCLUSION: Probably, TiO2 NP photocatalytic activity unbalanced ROS production which induced apoptosis and consequently reduced cell viability and metabolic activity at higher concentrations.

Cytotoxic Effects and Production of Cytokines Induced by the Endophytic Paenibacillus polymyxa RNC-D In Vitro.

BACKGROUND: Prominent among all the organisms that have a potential value for the production of new medicines, are endophytes, fungi and bacteria that live inside plants without harming them. In this study, a total lyophilized extract (TLE) of Paenibacillus polymyxa RNC-D was used. The P. polymyxa lineages are known for their capacity to segregate a large number of extracellular enzymes and bioactive substances. METHODS: The TLE of Paenibacillus polymyxa RNC-D was tested in cell viability assays for cytotoxicity and cytokine production in BALB/3T3 and J774A.1 cell lineages. RESULTS: A 50% mortality rate of fibroblasts (BALB/3T3) was observed in the 1.171±0.161 mg/mL and 0.956±0.112 mg/mL doses after 48 and 72 hours, respectively, as well as a 50% mortality rate of macrophage cells (J774A.1) in the 0.994±0.170 mg/mL and 0.945±0.280 mg/mL doses after 48 and 72 hours, respectively. The ≈1 mg/mL concentration significantly affected the kinetic of growth in all the measured periods. The extract induced apoptosis and necrosis 24 hours after the ≈1 mg/mL concentration in both tested lineages. The treatment with the ≈1 mg/mL concentration led to the production of TNF-α and IFN-γ cytokines in 24 hours. IL-12 and IL-10 began to be detected as a result of the treatment with 0.1 mg/mL. However, with the 0.5 mg/mL dose in 24 hours, a significant reduction in IL-10 was observed. CONCLUSION: Our data suggest that the TLE of P. polymyxa RNC-D modulated the production of cytokines with different patterns of immune response in a dose-dependent way.

Menthol and Menthone Associated with Acetylsalicylic Acid and Their Relation to the Hepatic Fibrosis in Schistosoma mansoni Infected Mice.

Schistosomiasis is an important parasitic disease caused by Schistosoma mansoni, an intravascular trematode. Schistosomiasis treatment is limited to just one drug, Praziquantel (PZQ). Thus, studies on new antischistosomal compounds are of fundamental importance to disease control. Here we report on the effects of Mentha piperita L. compounds - menthol and menthone - in association with acetylsalicylic acid (ASA) in the regulation of hepatic fibrosis caused by schistosomiasis granulomas. Six different groups of Swiss rats were infected with 80 cercariae. Two groups received only menthol and menthol treatment at different concentrations (30 and 50 mg/kg); two groups received treatment with the same concentration of menthol and menthol, but associated the ASA. All groups received treatment for 14 consecutive days from the 35 days after the parasitic infection. In addition, three other groups were used: uninfected and untreated group, infected and untreated group and infected group treated with the commercial drug (single dose). Parasitological, cytological and histological analyses were performed. Results showed a significant reduction on the number of eosinophils found in the peritoneal cavity lavage (LPC) in all treated groups and on the number of eosinophils found in the blood of PZQ treated group, in the blood of the group treated with 30 mg/kg of Mentaliv® and in the blood of group treated with 50 mg/kg Mentaliv® + ASA when compared to the infected group. All treated groups presented a reduction in the parasite load, represented by the number of S. mansoni eggs, in the experimental group treated with 30 mg/kg of menthol and menthone a 62.80% reduction was observed and in the experimental group treated with 50 mg/kg of menthol and menthone + ASA a reduction of 64.21% was observed. In the liver histological analysis we observed that all Mentaliv® treated groups expressed a unique cytological profile, with diffused cells through the granuloma. In the experimental group treated with 50 mg/kg of Mentaliv® + ASA it was possible to observe the formation of type III collagen fibers, a typical wound healing characteristic. Our data strongly suggest that both the hepatic fibrosis and the inflammatory process were regulated through the schistosomiasis granulomatous process after treatment with menthol and menthone associated with ASA.

Anti-Inflammatory Properties of Menthol and Menthone in Schistosoma mansoni Infection.

Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is believed that more than 261 million people are affected worldwide. New drug development has become essential because there is a risk of the parasite becoming resistant to Praziquantel, the only drug available for this infection. This study evaluated parasitological, immunological and histological parameters in mice infected with Schistosoma mansoni and treated with an herbal commercial medicine. This drug consists of menthol (30-55%) and menthone (14-32%). A 60 day treatment regimen with the herbal medicine decreased the number of S. mansoni eggs in the feces, liver, and intestine and reduced the number of hepatic granulomas. We observed a reduction of 84% in blood eosinophilia and a decrease in the IL-4 and IL-10 blood levels after treatment. Therefore, we propose that schistosomiasis treatment with this herbal medicine for 60 days has an immunomodulatory and anti-inflammatory action in this animal model for schistosomiasis thus contributing to the decrease in physio pathological effects caused by S. mansoni infection.