title: In vivo biochemical and gene expression analyses of the antioxidant activities and hypocholesterolaemic properties of Tamarindus indica fruit pulp extract.
abstract: BACKGROUND
  Tamarindus indica (T. indica) is a medicinal plant with many biological activities including anti-diabetic, hypolipidaemic and anti-bacterial activities. A recent study demonstrated the hypolipidaemic effect of T. indica fruit pulp in hamsters. However, the biochemical and molecular mechanisms responsible for these effects have not been fully elucidated. Hence, the aims of this study were to evaluate the antioxidant activities and potential hypocholesterolaemic properties of T. indica, using in vitro and in vivo approaches.
  
  
  RESULTS
  The in vitro study demonstrated that T. indica fruit pulp had significant amount of phenolic (244.9 ± 10.1 mg GAE/extract) and flavonoid (93.9 ± 2.6 mg RE/g extract) content and possessed antioxidant activities. In the in vivo study, hamsters fed with high-cholesterol diet for ten weeks showed elevated serum triglyceride, total cholesterol, HDL-C and LDL-C levels. Administration of T. indica fruit pulp to hypercholesterolaemic hamsters significantly lowered serum triglyceride, total cholesterol and LDL-C levels but had no effect on the HDL-C level. The lipid-lowering effect was accompanied with significant increase in the expression of Apo A1, Abcg5 and LDL receptor genes and significant decrease in the expression of HMG-CoA reductase and Mtp genes. Administration of T. indica fruit pulp to hypercholesterolaemic hamsters also protected against oxidative damage by increasing hepatic antioxidant enzymes, antioxidant activities and preventing hepatic lipid peroxidation.
  
  
  CONCLUSIONS
  It is postulated that tamarind fruit pulp exerts its hypocholesterolaemic effect by increasing cholesterol efflux, enhancing LDL-C uptake and clearance, suppressing triglyceride accumulation and inhibiting cholesterol biosynthesis. T. indica fruit pulp has potential antioxidative effects and is potentially protective against diet-induced hypercholesterolaemia.
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Chor Yin
authors.initials: CY
authors.lastname: Lim
authors.forename: Sarni
authors.initials: S
authors.lastname: Mat Junit
authors.forename: Mahmood Ameen
authors.initials: MA
authors.lastname: Abdulla
authors.forename: Azlina
authors.initials: A
authors.lastname: Abdul Aziz
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D006224:Cricetinae; D005419:Flavonoids / Q000032:analysis; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry*; D050356:Lipid Metabolism / Q000187:drug effects; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D059808:Polyphenols / Q000032:analysis; D029861:Tamarindus / Q000737:chemistry*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000924:Anticholesteremic Agents; D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D010936:Plant Extracts; D059808:Polyphenols; D017392:Thiobarbituric Acid Reactive Substances
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