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v2n2-jpans 1351844258

Mango Modulates Blood Glucose Similar to Rosiglitazone without Compromising Bone Parameters in Mice Fed High Fat Diet
Pages 115-126
Edralin A. Lucas, Angela Brown, Wenjia Li, Sandra K. Peterson, Yan Wang, Penny Perkins-Veazie, Stephen L. Clarke and Brenda J. Smith
DOI:
http://dx.doi.org/10.6000/1927-5951.2012.02.02.1
Published: 05 June 2012Open Access


Abstract: Both consumption of high-fat diet and one of the commonly used pharmacological therapies for modulating blood glucose, rosiglitazone, are associated with negative effects on bone. Previously, we reported that a diet supplemented with freeze-dried mango modulated blood glucose similar to rosiglitazone in mice fed a high-fat (HF) diet. This study examined the effects of the addition of freeze-dried mango pulp or rosiglitazone to a HF diet on bone parameters in mice. Six week old male C57BL/6J mice were randomly assigned into one of five dietary treatment groups (n=8-9 mice/group): control (9.5% calories from fat), HF (58.9% calories from fat), HF+1% or 10% mango (w/w), and HF+rosiglitazone (50 mg/kg diet) for eight weeks. Bone parameters were assessed via dual energy x-ray absorptiometry and micro-computed tomography. Both the HF and HF+rosiglitazone groups had lower whole body, tibial, and vertebral bone mineral density compared to the HF+1% mango group. Trabecular bone volume, number, and separation as well as bone strength were also compromised by HF+rosiglitazone while the mango diets maintained these bone microarchitecture parameters to that observed in the control group. These results suggests that addition of mango to the diet may provide an alternative approach to modulating blood glucose without negatively affecting skeletal health, though human studies are needed to confirm these findings. Additionally, the bioactive component(s) in mango and the mechanisms by which it modulates blood glucose and exerts potentially osteoprotective benefits warrants further investigation.

Keywords: Mango, high fat diet, rosiglitazone, bone.
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v2n2-jpans 1351844258

Effect of Grape Seed Extract on Blood Pressure in Subjects with Pre-Hypertension
Pages 155-159
M. Robinson, B. Lu, I. Edirisinghe and C.T. Kappagoda
DOI:
http://dx.doi.org/10.6000/1927-5951.2012.02.02.6
Published: 05 June 2012Open Access


Abstract: Pre-hypertension affects approximately 31% of the adult population of the United States over the age of 18 years. It is defined in the 7th report of the Joint National Committee (JNC - 7) on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure as a systolic blood pressure of 120-139 mmHg or a diastolic blood pressure of 80-89 mmHg. JNC-7 also recommended that individuals considered to be prehypertensive require health-promoting lifestyle modifications to prevent cardiovascular disease. This study was undertaken to determine whether a grape seed extract (GSE) which is a nutraceutical containing vasodilator phenolic compounds lowers blood pressure in subjects with pre-hypertension. The subjects were randomized into a placebo or an experimental group (GSE at a dose of 300 mg/day) and treated for 8 weeks. Serum lipids and blood glucose were measured at the beginning of the study and at the end. The blood pressure was recorded using an ambulatory monitoring device at the start of the treatment period and at the end. Both the systolic and diastolic blood pressures were significantly lower after treatment with GSE. Treatment with the placebo had no effect on blood pressure. There were no significant changes in serum lipids or blood glucose values. These findings suggest that GSE could be used as a nutraceutical in a lifestyle modification program for patients with pre-hypertension.

Keywords: Grape seed extract, pre-hypertension, human, polyphenolics.
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v2n2-jpans 1351844258

Quercetin Enhances Endurance Capacity via Antioxidant Activity and Size of Muscle Fibre Type 1
Pages 160-164
M. Robinson, B. Lu, I. Edirisinghe and C.T. Kappagoda
DOI:
http://dx.doi.org/10.6000/1927-5951.2012.02.02.7
Published: 05 June 2012Open Access


Abstract: This study aimed to examine effects of quercetin on 1) endurance capacity 2) malondialdehyde (MDA) and superoxide dismutase (SOD) activity in skeletal muscle and 3) muscle fibre density and size in mice after an intense exercise. There were 5 groups: control, vitamin C (250 mg/kg body weight), quercetin 150, 300, and 450 mg/kg body weight respectively once a day for 28 days. Endurance capacity was measured by exhaustive swimming exercise test which was done 24-h after swimming at high intensity. Then muscles were analyzed for MDA, SOD activity, and muscle fibre density and size. After the 28-day treatment, endurance time in vitamin C and quercetin treated groups at dose of 150 mg/kg body weight were longer than the vehicle group (p<0.05). MDA concentration in extensor digitorum longus muscle was lower than vehicle group in vitamin C, Q150 and Q450 groups and in soleus muscle the highest was in Q300 group. SOD activity in soleus muscle in Q150 group was higher than vitamin C and Q450 groups. Significant increase in cell diameter of soleus muscle was found (p<0.05). Current findings suggest that ingestion of quercetin can improve endurance capacity, due probably to increased antioxidant activity and size of muscle fibre type 1.

Keywords: Quercetin, oxidative stress, time to exhaustion, slow twitch muscle fibre.
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v2n2-jpans 1351844258

Effect of Short Term Sibutramine Supplementation on Appetite Suppression and Related Metabolic Responses
Pages 165-171
Swati Jain, Saroj K. Verma, Vijay K. Singh and Som Nath Singh
DOI:
http://dx.doi.org/10.6000/1927-5951.2012.02.02.8
Published: 05 June 2012Open Access


Abstract: The appetite suppressing property of Sibutramine is well reported. The present study was undertaken to investigate the appetite regulatory mechanism and associated metabolic changes induced in male Sprague Dawley rats by its short term supplementation. The effect of the drug on the regulatory hormones and biochemical variables was studied at an oral dose of 10 mg/kg body weight. There was a decrease in food intake of rats by 35.5% in comparison to their basal food intake as well as untreated controls. There was an increase in plasma levels of adiponectin, serotonin and a decrease in IGF-1 and corticosterone in the treated animals. The circulating levels of ghrelin marginally decreased with a corresponding increase in leptin and CCK in case of treated rats. These may be responsible for the anorectic effect of the drug.

Keywords: Sibutramine hydrochloride monohydrate, obesity, appetite, leptin, ghrelin, adiponectin.
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