Evaluation of vaccinal effectiveness of preparations containing membrane antigens of Leishmania (L.) amazonensis in experimental cutaneous leishmaniasis model.

American tegumentary leishmaniasis (ATL) is considered a neglected disease, for which an effective vaccine or an efficient diagnosis is not yet available and whose chemotherapeutic arsenal is threatened by the emergence of resistance by etiological agents such as Leishmania amazonensis. ATL is endemic in poor countries and has a high incidence in Brazil. Vaccines developed from native parasite fractions have led to the identification of defined antigenic subunits and the development of vaccine adjuvant technology. The purpose of the present study was to develop and compare preparations based on membrane antigens from L. amazonensis, as a biotechnological prototype for the immunoprophylaxis of the disease in a murine experimental model. For this purpose, batches of biodegradable polymeric micro/nanoparticles were produced, characterized and compared with other parasite's antigens in solution. All preparations containing membrane antigens presented low toxicity on murine macrophages. The in vivo evaluation of immunization efficacy was performed against a challenge with L. amazonensis, along with an evaluation of the immune response profile generated in BALB/C mice. The animals were followed for sample processing and quantification of serum-specific cytokines, nitrites and antibodies. The sera of animals immunized with the non-encapsulated antigen formulations showed higher intensities of nitrites and total IgGs. This approach evidenced the importance of the biological studies involving the immune response of the host against the parasite being interconnected and related to the subfractionation of its proteins in the search for more effective vaccine candidates.

Therapeutic potential of biodegradable microparticles containing Punica granatum L. (pomegranate) in murine model of asthma.

OBJECTIVE AND DESIGN: Among the options for treatment of diseases affecting the respiratory system, especially asthma, drug delivering systems for intranasal application represent an important therapeutic approach at the site of inflammation. The present study aimed to evaluate the therapeutic effect of biodegradable microparticles formed by poly lactic-co-glycolic acid (PLGA) containing encapsulated pomegranate extract on a murine model of asthma. MATERIAL: The extract was acquired from the leaves of P. granatum and characterized qualitatively by HPLC. A w/o/w emulsion solvent extraction-evaporation method was chosen to prepare the microparticles containing pomegranate encapsulated extract (MP). TREATMENT: OVA-sensitized BALB/c mice were used as asthma model and treated with dexamethasone and P. granatum extract in solution form or encapsulated into microparticles. RESULTS: MP were able to inhibit leukocytes' recruitment to bronchoalveolar fluid, especially, eosinophils, decreasing cytokines (IL-1ß and IL-5) and protein levels in the lungs. CONCLUSIONS: This approach can be used as an alternative/supplementary therapy based on the biological effects of P. granatum for managing inflammatory processes, especially those with pulmonary complications.