ABSTRACT
Aim: Long term consumption of dietary oils has been implicated in the etiology of hypertension. This study seeks to compare the effects of long term consumption of fresh palm oil (FPO) and thermoxidized palm oil (TPO) on baroreceptor reflex sensitivity (BRS), which is responsible for short term regulation of blood pressure. Methodology: The design of this study involved the use of eighteen, male, five month old New Zealand rabbits weighing 750 – 1000 g. They were divided into three groups (n = 6) as follows; control group (received normal animal feed only), FPO diet – fed group (received animal feed mixed with fresh palm oil in the ratio 85:15, respectively) and TPO diet – fed group (received animal feed mixed with thermoxidised palm oil in the ratio 85:15, respectively). The animals were fed for 6 months, after which they were used for the various experiments. Results: Mean daily food and water intake in FPO and TPO fed groups was significantly (p<0.001) lower compared with control. Heart rate for FPO group was significantly higher than the control (p<0.001) and TPO (p<0.01) group. Basal systolic and diastolic blood pressures were significantly higher in TPO group than in the FPO and control (p<0.05) group. The FPO group also had a significantly lower basal systolic (p<0.01) and diastolic pressure (p<0.001) than the control group. The basal pulse pressure was significantly lower in the FPO group than the control (p<0.001) and the TPO group (p<0.01). The mean arterial pressure (MAP) for TPO group was significantly higher (p<0.001) than that of control and FPO groups. The baroreflex sensitivity for FPO group was significantly reduced compared with control (p<0.01) and TPO group (p<0.05). The TPO group showed a significantly lower (p<0.01) baroreflex sensitivity, compared with control. Conclusion: This study observed that chronic consumption of both fresh and thermoxidised palm oil diets caused a significant reduction in carotid baroreceptor reflex sensitivity. However, reduction in BRS was more in fresh palm oil – diet fed group, than the thermally oxidized palm oil diet – fed.
ABSTRACT
Aims: Garcinia kola is used in West African countries for the treatment of various ailments such as cough, tooth decay, asthma and menstrual cramps. The inhibitory effect of Garcinia kola seed extract (GKE) on drug-induced contractions was studied on iliac smooth muscle preparations of guinea pig to ascertain the validity of the use of Garcinia kola in traditional medicine and to elucidate its possible mechanism of action. Place and Duration of Study: The study was done in Post Graduate Laboratory, Department of Pharmacology, College of Medical Sciences, University of Calabar, Calabar-Nigeria, between November 2013 and April 2014. Methodology: The antispasmodic influence of GKE (0.02 – 1 mg/ml) on acetylcholine, histamine and potassium chloride -induced contractions were carried out. The effect of GKE in a Ca2+-free Tyrode medium and in the presence of adrenergic antagonists was also investigated. Results: The results revealed that GKE inhibited or attenuated the spasmogenic effects of histamine and potassium chloride in a dose-dependent manner and shifted their log. doseresponse curves to the right, with pA2 values of 2.09±0.06 and 3.25±0.07 respectively. Preadministration of propranolol, prazosin or labetalol had no attenuating influence on the antispasmodic effect of GKE. Iliac smooth muscle responses to cumulative increased [Ca2+] in a depolarizing bathing medium and in a Ca2+- free Tyrode solution were also blocked. Comparative antispasmodic potencies indicated that papaverine and aminophylline were more potent than the extract. Conclusion: These findings suggest that Garcinia kola seed extract acts neither via cholinergic nor adrenergic receptor mediation, but may involve interference with Ca2+ mobilization, thus sharing with papaverine and/or aminophylline similar mechanism(s) of action.
ABSTRACT
Diabetes mellitus (DM)is a multi-factorial disease which is characterized by hyperglycaemia, lipoprotein abnormalities and oxidative stress. This study evaluated effect of oral vitamin C administration on basal metabolic rate and lipid profile of alloxan-induced diabetic rats. Vitamin C was administered at 200 mg/kg body wt. by gavage for four weeks to diabetic rats after which the resting metabolic rate and plasma lipid profile was determined. The results showed that vitamin C administration significantly (p less than 0.01) reduced the resting metabolic rate in diabetic rats; and also lowered plasma triglyceride, total cholesterol and low-density lipoprotein cholesterol. These results suggest that the administration of vitamin C in this model of established diabetes mellitus might be beneficial for the restoration of basal metabolic rate and improvement of lipid profile. This may at least in part reduce the risk of cardiovascular events seen in diabetes mellitus.