Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo).

Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.

Oxidative stress among subjects with metabolic syndrome in Sokoto, North-Western Nigeria.

BACKGROUND: Oxidative stress is known to play a role in the pathophysiology of metabolic syndrome and its components. Racial differences may exist in the level of markers of oxidative stress and antioxidants in patients with metabolic syndrome. AIM: The aim of this study was to determine the oxidative stress and antioxidants status in subjects with metabolic syndrome in Sokoto, North-Western Nigeria. METHODS: A cross-sectional community-based study was carried out. Two hundred subjects (96 males and 104 females) were recruited for the study using a multi-stage sampling technique. Demographic data were obtained from the participants. Evaluation of anthropometric variables, blood pressure, blood glucose levels, lipid profiles, plasma insulin levels, total antioxidant status, and oxidative stress markers was performed. RESULTS: The subjects with metabolic syndrome had significantly higher malondialdehyde as compared to those without metabolic syndrome (236.4 [92.2] vs. 184 [63.2] nmol/l). The antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) were significantly lower in subjects with metabolic syndrome than in those without metabolic syndrome (11.3 [4.2] vs. 13.9 [4.1] U/ml, 160[42] vs. 220[32] U/ml, and 2.12 [0.2] vs. 2.42 [0.2] U/ml, respectively). Similarly, the antioxidant Vitamins (A, C, and E) levels were significantly lower in subjects with metabolic syndrome than in those without metabolic syndrome (7.1 [4.1] vs. 7.7 [4.2] µmol/L, 225 [55.3] vs. 227.6 [62.3] µmol/L, and 75.9 [13.9] vs. 82.8 [18.6] mg/dl, respectively). There was a positive correlation between components of metabolic syndrome and free radicals. CONCLUSION: Significantly increased oxidative stress and diminished antioxidant defenses were found among Nigerians with metabolic syndrome.

Effect of Aqueous Stem Bark Extract of Khaya senegalensis on Some Biochemical, Haematological, and Histopathological Parameters of Rats.

The subchronic effect of aqueous stem bark extract of Khaya senegalensis on some biochemical, haematological, and histopathological parameters of rats was investigated. The rats were divided into six groups of five rats per group. Groups I to VI were administered graded doses of 0, 400, 800, 1200, 1600, and 2000 mg/kg bw, respectively. The result of study revealed that administration of the Khaya senegalensis for twenty-eight days at the experimental dose resulted in significant (P < 0.05) increase in urea, electrolytes (Na(+), K(+)), and creatinine levels. The extract also significantly (P < 0.05) increased serum activity of ALT, AST, and ALP. The levels of protein, albumin, and bilirubin were significantly changed when compared to their control values, but they were not dose dependent. The hematological indices assayed in this study were not significantly affected at the experimental dose when compared to the control values. Histological studies of the liver showed cellular degeneration and necrosis and bile duct hyperplasia and fibrosis with lymphocytic infiltration of the hepatocyte, providing supportive evidence for discussing the biochemical findings, indicative of functional derangement. The histological architecture of the kidney and that of the heart were however preserved. The result of this study indicates that the aqueous stem bark extract of K. senegalensis may affect the cellular integrity of vital organs of the body.

Effect of antioxidant mineral elements supplementation in the treatment of hypertension in albino rats.

Oxidative stress has been implicated in various pathologies, including hypertension, atherosclerosis, diabetes, and chronic renal disease. The current work was designed with the aim of investigating the potentials of antioxidants copper, manganese, and zinc in the treatment of hypertension in Wistar rats. The rats were fed 8% NaCl diet for 5 weeks and treatment with supplements in the presence of the challenging agent for additional 4 weeks. The supplementation significantly decreased the blood pressure as compared with hypertensive control. The result also indicated significant decreased in the levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol and very low-density lipoprotein cholesterol, malondialdehyde, insulin and increase in the high-density lipoprotein cholesterol, total antioxidant activities, and nitric oxide of the supplemented groups relative to the hypertensive control. The average percentage protection against atherogenesis indicated 47.13 ± 9.60% for all the supplemented groups. The mean arterial blood pressure showed significant positive correlation with glucose, total cholesterol, triglyceride, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, atherogenic index, insulin resistance and malondialdehyde while high density lipoprotein-cholesterol and total antioxidant activities showed negative correlation. The result therefore indicated strong relationship between oxidative stress and hypertension and underscores the role of antioxidant minerals in reducing oxidative stress, dyslipidemia, and insulin resistance associated with hypertension.

Effect of vitamins a, C, and e supplementation in the treatment of metabolic syndrome in albino rats.

Obesity and metabolic syndrome increase the risk of cardiovascular morbidity and mortality. Oxidative stress seems to be involved in the path physiology of cardiovascular complications of metabolic syndrome. In this study we investigated the effects of vitamins A, C, and E in the management of metabolic syndrome traits condition in albino rats fed with high salt diet. The rats were placed on 8% NaCl diet for 5 weeks and then supplemented with these vitamins for additional 4 weeks in the presence of salt diet. Supplementation with vitamins significantly (P < 0.01 ) decreased blood pressure of the rats as compared with the control. Supplementation also significantly (P < 0.05) reduced serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, and very-low-density lipoprotein cholesterol and increased high-density lipoprotein cholesterol, and total antioxidant status as compared with untreated group. The percentage protection of the supplemented groups against atherogenesis indicated 55.50 ± 3.75%. Percentage weight gain indicated significant positive correlation with triglyceride, insulin resistance, and malondialdehyde while total antioxidant status and nitric oxide showed significant negative correlation. Salt diet significantly (P < 0.05) induced features of metabolic syndrome. The result, therefore, indicated strong relationship between obesity and metabolic syndrome and underscores the role of these vitamins in the management of metabolic syndrome.

Salt taste perception and relationship with blood pressure in type 2 diabetics.

Patients with type 2 diabetes (normotensives, n=59; hypertensives, n=56) and matched controls (n=60) had salt taste perception determined using graded NaCl solutions ( 0-400 mmol 1(-1)). Diabetic hypertensives, diabetic normotensives and controls differed significantly in taste threshold to NaCl recognition (F=4.4, P=0.01) and prevalence of NaCl taste insensitivity (P=0.003). Taste threshold to NaCl recognition correlated positively with duration of diabetes (r=0.402, P=0.04) and was associated with mean arterial pressure (P<0.001), the association being significant after adjustment for age (P<0.001), gender (P< 0.001), family history of hypertension ( P< 001), body mass index (P<0.01), antihypertensive medication ( P<0.01) and proteinuria ( P<0.04).