Peripheral effects induced in BALB/c mice infected with DENV by the intracerebral route.

The lack of an immunocompetent animal model for dengue mimicking the disease in humans is a limitation for advances in this field. Inoculation by intracerebral route of neuroadapted dengue strains in mice is normally lethal and provides a straightforward readout parameter for vaccine testing. However, systemic effects of infection and the immune response elicited in this model remain poorly described. In the present work, BALB/c mice infected by the intracerebral route with neuroadapted DENV2 exhibited several evidences of systemic involvement. DENV-inoculated mice presented virus infective particles in the brain followed by viremia, especially in late stages of infection. Infection induced cellular and humoral responses, with presence of activated T cells in spleen and blood, lymphocyte infiltration and tissue damages in brain and liver, and an increase in serum levels of some pro-inflammatory cytokines. Data highlighted an interplay between the central nervous system commitment and peripheral effects under this experimental condition.

Single dose toxicity study of beta-myrcene, a natural analgesic substance

The present study was undertaken to provide date on acute toxicity of ß-myrcene, a peripheral analgesic substance found in the essential oils of several plants. Although myrcene has long been used in perfumes and as a food additive, there is almost no information on its toxicological hazards. The acute oral toxicity of myrcene was low in rodents, with with approximate lethal doses (ALD) of 5.06g/Kg body weight for mice and greater than 11.39 g/Kg body weight for rats. Necropsy data did not reveal any relevant alteration in rats but histophatology findings in mice suggested that the liver and stomach may be target organs for myrcene toxicity after oral administration. Myrcene is highly irritant to the peritoneum, and deaths after intraperitoneal injection of this monoterpene in rats (ALD 5.06 g/Kg body weight) and in mice (ALD 2.25 g/Kg body weight) were probably due to drug-induced chemical peritonitis