Bioatividades do extrato da folha da mangueira (Mangifera indica, variedade Ubá) e da mangiferina em camundongos ApoE-/-

• Autor(a) principal: Araújo, Bruna Moraes
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/322
• topic: Mangifera indica; Camundongos ApoE-/-; Mangifera indica; ApoE-/- mice; CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::METABOLISMO E BIOENERGETICA

Mangifera indica L. leaf extracts are an important source of phenolic compounds, especially mangiferin, a compound that exhibits antidiabetic, hypolipidemic, anti-oxidant and anti-inflammatory activities. This study aimed to characterize M. indica leaf extract, comparing it with stem bark extract and to evaluate the bioactivities of mangiferin and ethanolic extract of M. indica leaf in ApoE-/- mice. Dried extracts of M. indica leaf and stem bark were obtained by percolation with etanol. Mangiferin was obtained by extraction and purification process carried out from M. indica leaves, been identified by HPLC and diode array spectroscopy. The detection of secondary metabolites classes in M. indica leaf and stem bark extracts were performed by thin layer chromatography. Total phenols and flavonoids contents were estimated by spectrophotometry, respectively, at 760 nm, using Folin-Ciocalteu reagent, and at 420 nm, using metanolic solution of aluminium chloride hexahydrate. The both extracts antioxidant activities in vitro were determined by colorimetric method of free stable radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH). The quantification of mangiferin in the M. indica leaf extract were performed by high performance liquid chromathography (HPLC).Fifteenweek old ApoE-/- mice were divided in4 groups according to the treatment: control - vehicle (dimethyl sulfoxide); E200 - 200 mg/kg/day M. indica leaf extract; E400 - 400 mg/kg/day M. indica leaf extract, M40 - 40 mg/kg/day mangiferin. Administrations of vehicle, extracts and mangiferin were performed every day by gavage during 8 weeks. Blood parameters were measured using enzymatic kits and atherosclerotic lesions were evaluated by en face method, measuring the lipid deposition area stained with Sudan IV. Hepatic and renal catalase activities were evaluated by H2O2decomposition rate measured spectrophotometrically from changes in absorbance at 240 nm. Hepatic and renal superoxide dismutase activities were measured by the method that involves generation of superoxide by pyrogallol autoxidation and the inhibition of superoxide-dependent reduction of 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). Hepatic gene expression of fat-specific protein 27 (FSP-27) were quantified by RT-PCR. Liver and renal fragments were fixed in Karnowsky solution and submitted to a routine histologic processing and 3&#956;m-sections were stained with hematoxylin and eosin. Volumetric density of micro and macrovesicular steatosi, macrophages and necrosis were measured in liver. Volumetric density of glomerulus and average glomerular area were measured in kidney. Statistical analysis were performed using Neuman-Keuls multiple comparisons test (p<0.05). The M. indica leaf extract presented the following values of total phenols, flavonoids and mangiferin: 212,7 ± 10,0 mg EAG/ g dry extract, 90,3 ± 1,32 mg ERT/ g dry extract and 120 mg/ dry extract, respectivily. In the DPPH assay, the M. indica leaf extract presented a IC50 5,2. In the bioassay using apoE-/- mice, M. indica leaf extract and isolated mangiferin treatments had no effect on blood levels of glucose, total cholesterol, HDL cholesterol, triglycerides and alanine aminotransferase, as well as on the percentage of aortic lipid deposition, on SOD and CAT activities and on FSP-27hepatic gene expression. Only the isolated mangiferin treatment increased the serum levels of aspartate aminotransferase and increased the glomerular volumetric density and the average area of the glomeruli. Mangiferin and M. indica leaf extract treatments promoted reduction in volumetric density of macro-lipid droplets, macrophages and necrosis in liver. It was concluded that the M. indica and mangiferin treatments, in this experimental condition, were ineffective in retarding the progression of atherosclerotic lesions, but they could minimize liver histopathological features, regardless of changes in the antioxidant enzymes activities and in the FSP-27 hepatic gene expression.