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.

Immunological and parasitological parameters in Schistosoma mansoni-infected mice treated with crude extract from the leaves of Mentha x piperita L.

Schistosomiasis is a chronic disease caused by an intravascular trematode of the genus Schistosoma. Praziquantel is the drug used for treatment of schistosomiasis; nevertheless failure of treatment has been reported. Consequently, the identification of new effective schistosomicidal compounds is essential to ensure the effective control of schistosomiasis in the future. In this work we investigated the immunomodulatory and antiparasitic effects of the crude leaves extract of Mentha x piperita L. (peppermint) on murine Schistosomiasis mansoni. Female Balb/c mice were infected each with 50 S. mansoni cercariae and divided into three experimental groups: (I) untreated; (II) treated daily with M. x piperita L. (100mg/kg) and III) treated on 1/42/43 days post-infection with Praziquantel (500mg/kg). Another group with uninfected and untreated mice was used as a control. Subsequently, seven weeks post-infection, S. mansoni eggs were counted in the feces, liver and intestine. Worms were recovered by perfusion of the hepatic portal system and counted. Sera levels of IL-10, IL-5, IL-13, IFN-γ, IgG1, IgE and IgG2a were assayed by ELISA. Animals treated with a daily dose of M. x piperita L. showed increased sera levels of IL-10, IFN-γ, IgG2a and IgE. Besides, M. x piperita L. treatment promoted reduction in parasite burden by 35.2% and significant decrease in egg counts in the feces and intestine.