Antidiabetic Activity of Aloe vera Leaves.

This research evaluated the potential of using the methanol extract of Aloe vera (L.) Burm.f (AVM) to prevent the formation of AGEs by means of the BSA/glucose assay, BSA-methylglyoxal assay, arginine-methylglyoxal assay, fructosamine, Nɛ-(carboxymethyl) lysine (CML), thiol groups, and carbonyl protein in vitro. The effect of AVM was also evaluated with regard to inhibiting the enzymes α-amylase, α-glucosidase, and pancreatic lipase. For this, the plant was dried, ground, and subsequently macerated with methanol. Aloe vera methanol extract (AVM) significantly decreased the formation of AGEs, as well as the formation of fructosamine, CML, and carbonyl protein. The concentration of 5 mg/ml of AVM presented the best results. AVM significantly inhibited the α-amylase and α-glucosidase enzymes. As regards the content of thiol groups, a significant increase was observed during the four weeks of the experiment. So, we can conclude that Aloe vera methanol extract decreases the formation of AGEs and may inhibit the increase in postprandial glucose, suggesting that AVM can prevent diabetes complications associated with AGE.

[Prevalence of immunologic markers (Anti-GAD and Anti-IA2) in first-degree relatives of patients with type I diabetes in the greater area of São Paulo]. / Prevalência dos marcadores imunológicos Anti-GAD e Anti-IA2 em parentes de primeiro grau de diabéticos do tipo I em amostra da população da Grande São Paulo.

BACKGROUND: Increasingly accurate prediction of Type I Diabetes Mellitus (DMI), based on analysis of autoantibody markers, has become possible in first-degree relatives of patients with diabetes (PDMI). These markers indicate autoimmune process against pancreatic islet beta-cells. Anti-GAD and anti-IA2 are considered predictive of DMI, whose prevalences are considerably variable in different populations studied. There are few data about the frequency of these markers on the Brazilian population. The aim of this study is determine the prevalence of positivity for anti-GAD and for anti-IA2 among DMI patients first-degree relatives (PDMI) in a sample of the Brazilian population of Great São Paulo City. METHODS: Forty-eight children and adolescents PDMI with median of age of 14.5 years (range 6.7 to 17.9 years). Anti-GAD and anti-IA2 was measured by radioassay (Kronus , USA). The cut-off limit for both antibodies was set at the 99th percentile from normal subjects serum samples (anti-GAD: n=194; Median of age=13.4 yrs; range 9.7 to 64 yrs; anti-IA2: n=71; Median of age=12.6; range 11.1-15.2 yrs). A subject was considered to be positive for anti-IA2 if specific binding exceeded the 99th among the analysis of 71 subjects. The limit to positivity was 1.72 U/ml to anti-GAD and 0.97 U/ml to anti-IA2. RESULTS: Five PDMI (10.4%) have showed positivity to anti-GAD, with significantly higher prevalence than controls (P<0.01). The anti-IA2 prevalence rate seems to be equivalent between PDMI and controls. CONCLUSION: The prevalence of anti-GAD has been more prevalent among the PDMI. No differences were observed between prevalences for anti-IA2 showed by PDMI and controls.

Prevalência dos marcadores imunológicos Anti-GAD e Anti-IA2 em parentes de primeiro grau de diabéticos do tipo 1 em amostra da população da Grande São Paulo / Prevalence of immunological markers (Anti-GAD and Anti-IA2) in first-degree relatives of patients with type 1 diabetes in Great São Paulo City

O diabetes tipo 1A (DM1) é causado por mecanismo auto-imune contra células beta em indivíduos com predisposição genética. Auto-anticorpos anti-GAD e anti-IA2 são considerados importantes marcadores destas alterações, cuja prevalência variam, segundo a população estudada e história familiar. Dados sobre freqüência desses marcadores na população brasileira são escassos. OBJETIVOS: Avaliar a freqüência de anti-GAD e anti-IA2 em parentes de primeiro grau de portadores de DM1 (PDM1) em amostra da população da Grande São Paulo. MÉTODOS: Quarenta e oito jovens PDM1 foram recrutados junto a 36 propósitos assistidos em ambulatórios especializados em diabetes da Grande São Paulo, apresentando mediana de idade de 14,5 anos (6,7 a 17,9 anos). Os valores de referência do anti-GAD foram obtidos utilizado-se soros de 194 voluntários normais, sem antecedentes familiares de DM1, com idade de 9,7 a 64,0 anos (mediana de 13,4). Soros de 71 indivíduos normais com idade variando de 11,1 a 15,2 anos (Mi= 12,6) foram submetidos à dosagem de anti-IA2. As dosagens dos marcadores foram através do radioensaio (KRONUS®, Idaho, USA). Valores acima do 99º percentil obtido no grupo controle foram considerados positivos. RESULTADOS: O 99º percentil correspondeu ao valor 1,72 U/ml para o anti-GAD e 0,97 U/ml para o anti-IA2. Cinco indivíduos dos PDM1 (10,4 por cento) foram positivos para o anti-GAD, contra 0,5 por cento dos controles (P<0,01). Um jovem do grupo PDM1 mostrou-se positivo para o anti-IA2 (2,1 por cento), com freqüência semelhante aos controles. CONCLUSÃO: O anti-GAD mostrou maior prevalência entre os PDM1, não havendo diferença entre o PDM1 e controles quanto à freqüência de anti-IA2