Submitted by Oliveira Flávia (flavia@sisbin.ufop.br) on 2014-02-11T17:39:07Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação_AtividadeFarmacológicaExtrato.pdf: 2357007 bytes, checksum: fc52b6484708f5d0470468f1916fe99e (MD5) / Approved for entry into archive by Gracilene Carvalho (gracilene@sisbin.ufop.br) on 2014-02-13T11:49:03Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação_AtividadeFarmacológicaExtrato.pdf: 2357007 bytes, checksum: fc52b6484708f5d0470468f1916fe99e (MD5) / Made available in DSpace on 2014-02-13T11:49:19Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação_AtividadeFarmacológicaExtrato.pdf: 2357007 bytes, checksum: fc52b6484708f5d0470468f1916fe99e (MD5) Previous issue date: 2013 / No Brasil, o acidente vascular cerebral e a doença arterial coronariana constituem as principais causas de mortalidade cardiovascular. Estudos clínicos de intervenção com hipolipemiantes mostraram que o controle do colesterol reduz a incidência não só da doença arterial coronariana, mas também do acidente vascular cerebral. Nesse contexto, extratos vegetais contendo antioxidantes ou substâncias isoladas capazes de reverter o estresse oxidativo, presente na hipercolesterolemia, podem ser promissores, reduzindo os riscos de doenças cardiovasculares. O objetivo desse estudo foi avaliar o potencial do extrato hidroalcoólico dos frutos de Hovenia dulcis e do flavonóide dihidromiricetina na redução do colesterol em ratos hipercolesterolêmicos. Para o experimento in vivo, 48 ratos Wistar machos, foram distribuídas em 8 grupos de 6 animais, que receberam dieta suplementada com 1,0% de colesterol e 0,3% de ácido cólico, a exceção do grupo controle que recebeu ração convencional. Os animais foram então tratados com suspensões orais contendo: atorvastatina 1,0 mg/Kg; extrato de H. dulcis (50,0 e 100,0 mg/kg); dihidromiricetina (25,0 e 50,0 mg/kg) e veículo inerte (grupo controle). Foram avaliados os parâmetros bioquímicos colesterol total, HDL-c, LDL-c, triglicérides, transaminases e fosfatase alcalina. Os tratamentos com as duas doses do extrato de H. dulcis mostraram-se eficazes como hipocolesterolemiantes, já que foram capazes de reduzir substancialmente os níveis séricos de colesterol total e LDL-c (até 33,3 e 51,5%, respectivamente), sem alterar significativamente os demais parâmetros bioquímicos. Já os grupos tratados com a dihidromiricetina, apesar de apresentarem reduções significativas no colesterol total e LDL-c, tiveram aumento nos parâmetros hepáticos e triglicérides, resultado indesejável no âmbito das hipercolesterolemias. Estudos farmacológicos com outras espécies animais devem ser realizados para comprovar a eficácia do extrato de H. dulcis na hipercolesterolemia, a segurança na sua utilização (estudos de toxicidade), as dosagens terapêuticas mais eficazes e os mecanismos de ação. _____________________________________________________________________________ / ABSTRACT: In Brazil, the principal causes of cardiovascular mortalities are strokes and cerebrovascular accidents. Clinical studies of intervention with hypolipidemic agents show that controlling cholesterol reduces not only the incidence of coronary artery disease, but also that of stroke. In this context, plant extracts containing antioxidants, or isolated substances capable of reverting oxidative stress under hypercholesterolemia, show promise in reducing the risks of cardiovascular diseases. The objective of this study was to evaluate the potential of the hydroalcoholic extract of the fruit of H. dulcis and of dihydromyricetin in cholestrol reduction in hypercholesterolemic rats. Forty-two Wistar male rats were distributed into seven groups of six animals that received diets supplemented with 1% cholesterol and 0.3% cholic acid, with the exception of the control group which received conventional rations. Animals were treated with oral suspensions containing: atorvastatin 1.0 mg/Kg; H. dulcis extract at 50.0 and 100.0 mg/kg and dihydromyricetin at 25.0 and 50.0 mg/kg vehicle (control group). The following biochemical parameters were evaluated; total cholesterol, HDL-c, LDL-c, trigycerides, AST, ALT, and alkaline phosphatase. The treatments with two doses of the extract proved to be promising hypocholesterolemic agents, as they were able to substantially reduce total cholesterol and LDL-c (up to 33.3 and 51.5%, respectively), without significantly altering the other biochemical parameters. As for the groups treated with the flavonoid dihydromyricetin, although they showed a significant reduction in total cholesterol and LDL-c, they showed increases in triglycerides and hepatic parameters, which is undesirable within the context of hypercholesterolemia. Pharmacological studies with other animal species should be conducted to prove the effectiveness of the extract of H. dulcis in hypercholesterolemia, safe use (toxicity studies), the most effective therapeutic dosages and mechanisms of action.