Zimvo Obasa1, Mignon Albertha van Vuuren2, Barbara Huisamen3, Shantal Lynn Windvogel4. 1. Centre for Cardio-metabolic Research in Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Email: maqeda@sun.ac.za. 2. Centre for Cardio-metabolic Research in Africa (CARMA),Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. 3. Centre for Cardio-metabolic Research in Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa; Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg, South Africa. 4. Centre for Cardio-metabolic Research in Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
Abstract
PURPOSE: Obesity is associated with the development of risk factors for cardiovascular disease (CVD) and polyphenols have been shown to possess ameliorative effects against obesity-induced CVD risk factors. Rooibos (Aspalathus linearis) is rich in polyphenols, therefore we investigated the cardioprotective effects of aspalathin-rich green rooibos (GRT) on obesity-induced CVD risk factors in obese Wistar rats. METHODS: Adult male Wistar rats (n = 20 per group) were fed a control or a high-fat diet (HFD) for 16 weeks and treated with GRT (60 mg/kg/day) for six weeks. Blood pressure was monitored throughout. Vascular reactivity was measured and Western blots of cell-signalling proteins (eNOS, AMPK and PKB) were performed in aortic tissues. Effects on oxidative stress were determined by measuring antioxidant enzyme activity and thiobarbituric reactive substance (TBARS) levels in the liver. RESULTS: HFD animals had (1) increased blood pressure, (2) impaired vasodilation, (3) attenuated PKB and AMPK expression, (4) decreased antioxidant enzyme activity, (5) increased malondialdehyde (MDA) levels, and (6) increased phosphorylated eNOS levels. Treatment with GRT extract significantly alleviated these obesity-induced CVD risk factors. CONCLUSIONS: Supplementation with GRT extract alleviated cardiovascular risk factors in the HFD animals, suggesting a therapeutic potential for GRT in obesity-induced cardiovascular risk.
PURPOSE: Obesity is associated with the development of risk factors for cardiovascular disease (CVD) and polyphenols have been shown to possess ameliorative effects against obesity-induced CVD risk factors. Rooibos (Aspalathus linearis) is rich in polyphenols, therefore we investigated the cardioprotective effects of aspalathin-rich green rooibos (GRT) on obesity-induced CVD risk factors in obese Wistar rats. METHODS: Adult male Wistar rats (n = 20 per group) were fed a control or a high-fat diet (HFD) for 16 weeks and treated with GRT (60 mg/kg/day) for six weeks. Blood pressure was monitored throughout. Vascular reactivity was measured and Western blots of cell-signalling proteins (eNOS, AMPK and PKB) were performed in aortic tissues. Effects on oxidative stress were determined by measuring antioxidant enzyme activity and thiobarbituric reactive substance (TBARS) levels in the liver. RESULTS: HFD animals had (1) increased blood pressure, (2) impaired vasodilation, (3) attenuated PKB and AMPK expression, (4) decreased antioxidant enzyme activity, (5) increased malondialdehyde (MDA) levels, and (6) increased phosphorylated eNOS levels. Treatment with GRT extract significantly alleviated these obesity-induced CVD risk factors. CONCLUSIONS: Supplementation with GRT extract alleviated cardiovascular risk factors in the HFD animals, suggesting a therapeutic potential for GRT in obesity-induced cardiovascular risk.
Authors: Sithandiwe E Mazibuko; Elizabeth Joubert; Rabia Johnson; Johan Louw; Andrew R Opoku; Christo J F Muller Journal: Mol Nutr Food Res Date: 2015-09-15 Impact factor: 5.914
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