Pulmonary functions and anthropometric parameters of young male and female adults participating in moderate aerobic exercise.

Respiratory disorders may be one of the adverse effects of sedentary lifestyle. This study investigated respiratory functions (FEV1, FVC and PEFR) and anthropometric parameters (body weight and body mass index) of healthy young males and females participating in moderate aerobic exercise. Forty young healthy untrained non-athletes, twenty males and twenty females (age, 25 ± 5.6 years; body weight, 65 ± 4.0 kg; body height, 176.9 ± 2.5 cm) volunteered to participate in this study. The exercise regimen was of moderate intensity lasting for 20 min daily on a treadmill consistently at the speed of 13 km/h for 14 days. The weight and height of participants were measured using medical scale and wall-mounted stadiometer respectively. The forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were assessed using digital spirometer. The results showed a significant (p < 0.05) decrease in body weight and body mass index of female participants after 14 days of exercise regimen. The FEV1, FVC and PEFR were significantly increased (p < 0.05) in both male and female subjects after exercise. The Pearson correlation showed a significant (p < 0.05) positive correlation between BMI with FEVI/FVC% in female participants. There was an increase in calories burnt from day 4 of the study in both male and female participants. It is concluded that moderate aerobic exercise improved respiratory functions (FEV1, FVC and PEFR) in both male and female subjects with greater improvement in females while reducing body weight and body mass index in females.

Identification of phytochemicals and assessment of hypoglycemic and haematological potentials of Terminalia catappa Linn leaf extract in alloxan-induced diabetic Wistar rats.

INTRODUCTION: Hypoglycemia and anemia are associated with diabetes mellitus. Medicinal plants and orthodox drugs have been used for the management of this disease. This study aimed to validate the ethnomedical claims of Terminalia catappa Linn. leaf extract in reducing hyperglycemia and hematological potentials in alloxan-induced diabetic rats and to identify likely antidiabetic compounds. MATERIALS AND METHODS: Ultra-high-performance liquid chromatography was used to identify the various phytochemical constituents. Male Wistar rats were randomly divided into five groups containing 6 rats per group. Group 1 (control) received 0.2 ml/kg of distilled water, group 2 received 130 mg/kg of T. catappa aqueous extract, groups 3-5 were diabetic and received 0.2 ml/g distilled water, 130 mg/kg T. catappa extract and 0.75 IU/kg insulin respectively for 14 days. Hematological parameters were measured and an oral glucose tolerance test was carried out using 2 g/kg body weight glucose. A histological analysis of the pancreas was done. RESULTS: Twenty-five compounds identified as flavonoids, phenolic acids, tannins, and triterpenoids were detected. The blood glucose levels were significantly (p<0.05) elevated in DM groups but were significantly (p<0.05) reduced following Terminalia catappa leaves extract to DM groups. There was s significant (p<0.05) increase in insulin levels improved hematological parameters (RBC, WBC, and platelets), and increased islet population. CONCLUSION: These results suggest that T. catappa extract has hypoglycemic, insulinogenic, and hematopoietic potentials in diabetic condition and offer protection to the pancreas which could be attributed to the phytochemical constituents thereby justifying its use in traditional therapy.

Profile of a Don - Prof. Eme Osim Retires.

Prof Eme E. Osim served Editor-in-Chief of Nigerian Journal of Physiological Sciences between 1999 and 2009. This tribute highlights his immense contributions to the development of the journal and academia.

Cardiac and Renal Protective Effect of Vitamin E in Dexamethasone-Induced Oxidative Stressed Wistar Rats.

Vitamin E has been used as antioxidant and in the treatment of various ailments due to oxidative stress. The cardio-protective effect of vitamin E in dexamethasone induced oxidative stress was studied. Forty Wistar rats were randomly assigned to four groups of 10 rats each. Control group received normal rat chow. Oxidative stress was induced using 30µg/kg body weight of dexamethasone (DEX) intraperitonealy in DEX+Vit E and DEX only groups while Vitamin E was administered orally at a dose of 300 IU/kg to Vitamin E only group and DEX+Vit E group daily for 14 days. All animals were fed ad libitum and had free access to water. Blood samples were obtained by cardiac puncture for biochemical analyses while heart and kidney were processed for histological staining.  The result shows a significant (p<0.05) decrease in serum nitric oxide, bilirubin and superoxide dismutase concentration in DEX-only group which was elevated following vitamin E treatment. The angiotensin converting enzyme and lactate dehydrogenase enzyme activities were significantly (p<0.01) elevated in DEX-only group compared with control and DEX+Vit E groups. These enzyme levels were significantly (p<0.01) reduced in DEX + vitamin E group. The histology of the heart and the kidney in DEX-only group showed cardiac hypertrophy and kidney injury but were ameliorated by vitamin E treatment. The results suggest that vitamin E has cardiac and renal protective effect and ameliorates oxidative injury to the heart and kidney due to oxidative stress.

Blood pressure-reducing activity of Gongronema latifolium Benth. (Apocynaeceae) and the identification of its main phytochemicals by UHPLC Q-Orbitrap mass spectrometry.

Background Gongronema latifolium Benth. (family Apocynaceae) leaves (GL) has interesting medicinal properties. The effects of extracts from G. latifolium on blood pressure (BP) and the possible mechanisms of action were also investigated. Methods The ultrahigh resolution liquid chromatography orbitrap MS analysis was used to identify the phytochemicals present. Normotensive Wistar rats were anesthetized with sodium pentobarbitone (40 mg/kg) intraperitoneally, and the jugular vein was cannulated for infusion of drugs while the carotid artery was cannulated for direct BP measurement. GL extract (5-20 mg) alone or with nifedipine (10 mg/kg), atropine (2 mg/kg), L-NAME (5 mg/kg), methyl blue (3 mg/kg) and propranolol (1 mg/kg) were administered intravenously to Wistar rats and direct BP measurements were carried out. Results Systolic and diastolic BP levels (128/90 mm Hg; MAP 103 ± 3 mm Hg) and heart rates were all significantly (p < 0.01) decreased after GL administration. Raised mean arterial pressure (MAP) and heart rate by atropine, L-NAME and methyl blue were significantly (p < 0.01) reduced after GL administration, while propranolol significantly (p < 0.01) inhibited hypotension caused by GL. Infusion of GL reduced MAP (95 ± 3 mm Hg) comparable with nifedipine (93 ± 2 mm Hg), a calcium channel blocker. The phytochemicals identified were 34 compounds, including oleanolic acid derivatives, flavonoids, antioxidant fatty acids, 2 coumarins and 2 iridoids. Conclusions These results suggest that G. latifolium has hypotensive properties mediated by the synergistic activity of the compounds, probably via the ß-adrenergic blockade mechanism.

Altered Potassium Ion Channel Function as a Possible Mechanism of Increased Blood Pressure in Rats Fed Thermally Oxidized Palm Oil Diets.

Intake of thermally oxidized palm oil leads to cytotoxicity and alteration of the potassium ion channel function. This study investigated the effects of fresh and thermally oxidized palm oil diets on blood pressure and potassium ion channel function in blood pressure regulation. Male Wistar rats were randomly divided into three groups of eight rats. Control group received normal feed; fresh palm oil (FPO) and thermally oxidized palm oil (TPO) groups were fed a diet mixed with 15% (weight/weight) fresh palm oil and five times heated palm oil, respectively, for 16 weeks. Blood pressure was measured; blood samples, hearts, and aortas were collected for biochemical and histological analyses. Thermally oxidized palm oil significantly elevated basal mean arterial pressure (MAP). Glibenclamide (10-5 mmol/L) and tetraethylammonium (TEA; 10-3 mmol/L) significantly raised blood pressure in TPO compared with FPO and control groups. Levcromakalim (10-6 mmol/L) significantly (p < .01) reduced MAP by 32.0% in FPO and by 5.4% in TPO. NS1619 (10 mmol/L) significantly (p < .01) decreased MAP by 19.5% in FPO and by 8% in TPO. The TPO significantly (p < 0.01) increased the tissue levels of peroxide, total cholesterol, triglyceride, and low-density lipoprotein cholesterol while catalase and superoxide dismutase activities were significantly (p < .01) decreased compared with control and FPO groups. Histological alterations were prominent in aortas and hearts of rats in the TPO group. These results suggest that prolonged consumption of repeatedly heated palm oil increases MAP probably due to the attenuation of adenosine triphosphate-sensitive potassium (KATP) and large-conductance calcium-dependent potassium (BKCa) channels, tissue peroxidation, and altered histological structures of the heart and blood vessels.

Effect of Vitamin C Supplementation on Platelet Aggregation and Serum Electrolytes Levels in Streptozotocin-Induced Diabetes Mellitus in Rats.

Diabetes mellitus (DM) is a disease condition characterised by hyperglycemia; free radical and abnormalhaematological indices. Vitamin C can reduce free radical generation and ameliorate adverse conditions of diabetes mellitus.The aim of the present study is to investigate the effect of vitamin C on platelet aggregation and electrolyte levels in Type 1DM. Male Wistar rats were divided into four groups namely control, DM, DM +Vitamin C and Vitamin C groups. Rats weremade diabetic with a single dose of streptozotocin (65 mg/kg) intraperitoneally. Vitamin C was administered orally todiabetic and normal rats at 200 mg/kg body weight for 28 days. Blood samples were analyzed for hematological parameters,platelet aggregation, and serum electrolyte levels. Blood glucose in DM+ Vitamin C group (9.9 ± 1.8 mmol/L) wassignificantly reduced (p<0.01) compared to DM group (32.2 ± 2.1 mmol/L) and significantly higher (p<0.05) than control(4.4 ± 0.8 mmol/L). Haemoglobin (Hb) concentration in DM group (12 ± 0.1 g/dL) was significantly reduced (p<0.01) whencompared with control groups (14 ± 0.24 g/dL) and significantly increased (p<0.05) in the DM+vitamin C group (13.5 ± 0.5g/dL) compared with the diabetic group. The mean corpuscular volume values in DM (68.66 ± 0.5 fL) and DM+vitamin Cgroups (68.11 ± 0.4 fL) were significantly higher (p<0.01) than the control (59.49 ± 0.5fL). Platelet count in DM group (523± 8.5 x109/L) was significantly raised (p<0.01) when compared to control (356 ± 6.2 x109/L) and significantly reduced(p<0.01) in DM+ vitamin C-treated group (385 ± 7.8 x109/L) compared with DM group. Platelet aggregation and serumsodium/potassium ratios was significantly reduced (p<0.01) in DM+vitamin C compared with DM group. These resultssuggest that oral vitamin C administration increases haemoglobin, reduced plasma glucose level, platelet count, serumsodium/potassium ion ratio and inhibits platelet aggregation in streptozotocin-induced DM in rats.

Investigation of effects of time of measurement and modes of administration on cadmium accumulation in rat liver under some medicinal plants food supplemented diet.

CONTEXT AND OBJECTIVES: Cadmium (Cd) toxicity leads to cell and organ damage, we comparatively examined the protection ability of different medicinal plants on Cd liver accumulation following different treatment interventions and modes of administration. MATERIALS AND METHODS: Rats were fed either 7% w/w Zingiber officinale, 7% w/w Allium Sativum, 10% w/w Lycopersicon esculentum, 5%, w/w Garcinia kola (all in rat chow), while Cd (200 ppm) was given in drinking water. Additives were administered together with (mode 1), a week after (mode 2) or a week before metal exposure (mode 3) for a period of six weeks. Cd liver was determined using AAS and compared using analysis of variance (ANOVA). RESULTS: All additives significantly (P <0.5) reduced the accumulation of Cd in the liver. After adjusting for time and mode of administration, mean %protection for week 4 was significantly lower by 14.1% (P=0.02) from that for week 2 but the means did not differ with respect to additive used or mode of administration, no statistically significant interaction between modes of administration and either of additives used or time of administration in their respective relationships to percentage protection from Cd. CONCLUSION: Additives significantly reduced Cd accumulation through a reduction in absorption and enhancement of metal excretion.

Attenuated vascular responsiveness to K+ channel openers in diabetes mellitus: the differential role of reactive oxygen species.

The current study examined the responsiveness of blood vessels from diabetic rats to K+ channel openers and explored whether ROS might be involved in any changes. Responses were measured in aortic rings isolated from four weeks streptozotocin (65 mg/kg)-induced diabetic rats. Relaxation to levcromakalim (ATP-sensitive potassium channel KATP opener, 10(-9)-10(-5) mol/l) and (+/-)-naringenin (large conductance calcium-activated channel BKCa opener, 10(-8)-10(-3) mol/l) were recorded in phenylephrine (1 µmol/l) pre-contracted segments in the absence and presence of superoxide dismutase (SOD, 100 µmol/l) and apocynin (an antioxidant and inhibitor of NADPH oxidase, 100 µmol/l). Contractions to phenylephrine (10(-9)-10(-5) mol/l) and relaxation to acetylcholine (ACh, 10(-9)-10(-5) mol/l) were also recorded. Relaxation curves for levcromakalim, naringenin and ACh for the diabetic group were shifted to the right (p < 0.05) compared with the control. Contractions to phenylephrine were enhanced in the diabetic group (p < 0.01). SOD restored the ACh response but not those of K+ channel openers. On the other hand, apocynin restored the relaxation to naringenin but had no effect on both levcromakalim and ACh responses. The results suggest that both KATP and BKCa activities are attenuated in diabetes mellitus and that ROS appears to contribute only to the change in BKCa function.

Comparative study on the hepatoprotection to heavy metals of Zingiber officinale.

CONTEXT: Zingiber officinale (Zingiberaceae) is a herb used for culinary and therapeutic purposes due to its anti-inflammatory and antioxidant potentials. OBJECTIVES: We examined its protective ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. MATERIALS #ENTITYSTARTX00026; METHODS: Ground Zingiber officinale (7%, w/w of feed) was administered to rats either at the same time with the exposure ofheavy metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. Animals were exposed to either of Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) in drinking water. The heavy metal accumulations in the liver were determined using AAS. RESULTS: Weight losses induced by these metals were not reversed by Zingiber officinale administration. There was a significant (P<0.01) increase in protection to Pb (97%) and Cd (63%) accumulation when compared to Hg (32%) at week 2. The protective ability was significantly (P<0.01) decreased at week 4 when compared to week 2 for Cd and Pb but not to Hg in groups 3 (50%) and 4 (52%). At week 6, hepatoprotection to Hg (44%) and Cd (85%) was significantly (P<0.01) different but not to Pb which was only significant (P<0.05) in week 2 of treatment for all groups. DISCUSSION AND CONCLUSION: Zingiber officinale affected the bioavailability, elimination and uptake of these metals in a time-dependent way with highest beneficial reducing effect to Cd followed by Hg and least protection to Pb in the liver.

Comparative analysis on the effect of palm oil (Elaeis guineensis) in reducing cadmium and lead accumulation in liver of Wistar rats.

CONTEXT: Palm oil from Elaeis guineensis is an edible nutrient substance with anti-inflammatory and antioxidant properties. We examined its protective effect against lead (Pb) and cadmium (Cd) accumulation in the liver. MATERIALS AND METHODS: 12% w/w of palm oil (PO) in rat chow concentrate was fed to rats exposed to Cd (200ppm) and Pb (100ppm) in drinking water at different feeding regimens. PO was administered either at the same time with the metals (group 2), post-treatment after exposure (group 3) or pre-treatment before exposure (group 4) for six weeks. The heavy metal accumulations in the liver were determined using AAS. RESULTS: Weight losses induced by these metals were significantly (P<0.05) reversed by PO administration. Analysis among the groups showed that post-treatment group had a significant (P<0.05) higher percentage protection to Cd, but same time treatment for Pb (P<0.05) when compared with other groups. The protective ability to PO was only significantly (P<0.05) increased for Pb at week 2, but showed a time-dependent significant (P<0.05) increase for Cd across all treatment regimens. CONCLUSION: PO is beneficial in reducing metal accumulation in the liver and has a higher hepatoprotective effect to Cd compared to Pb at the selected doses by possibly affecting the processes of uptake, assimilation and elimination of these metals.

Possible mechanisms of action of the hypotensive effect of Annona muricata (soursop) in normotensive Sprague-Dawley rats.

CONTEXT: Annona muricata Linn (Annonaceae) (soursop) is a food plant reported to have antihypertensive properties. OBJECTIVE: We investigated the blood pressure reducing effect of its aqueous leaf extract and the possible mechanisms that may be responsible. METHODS: Intravenous administration of an aqueous leaf extract (9.17-48.5 mg/kg) of A. muricata on the mean arterial pressure and heart rate were recorded invasively on anaesthetized, normotensive Sprague-Dawley rats. Contractile responses of rat aortic rings to the extract (0.5-4.0 mg/mL) were studied using standard organ bath techniques. RESULTS: A. muricata (9.17-48.5 mg/kg) caused significant (p < 0.05) dose-dependent reduction in blood pressure without affecting the heart rates. The hypotensive effects were unaffected by atropine (2 mg/kg), mepyramine (5 mg/kg), propranolol (1 mg/kg) and L-NAME (5 mg/kg). A. muricata leaf aqueous extract significantly (p < 0.05) relaxed phenylephrine (10(-9)-10(-4) M) and 80 mM KCl induced contractions in endothelium intact and denuded aortic rings; and caused a significant (p < 0.05) rightward shift of the Ca(2+) dose response curves in Ca(2+)-free Kreb's solution containing 0.1 mM EGTA. CONCLUSIONS: The hypotensive effects of A. muricata are not mediated through muscarinic, histaminergic, adrenergic and nitric oxide pathways, but through peripheral mechanisms involving antagonism of Ca(2+).

Possible mechanisms of action of the aqueous extract of Artocarpus altilis (breadfruit) leaves in producing hypotension in normotensive Sprague-Dawley rats.

CONTEXT AND OBJECTIVES: Artocarpus altilis (Parkinson) Fosberg (Moraceae) (breadfruit) leaves are used as an antihypertensive remedy. We investigated the possible mechanisms of action of its aqueous extract and its effect on cytochromes P450 (CYP) enzyme activities. MATERIALS AND METHODS: Intravenous administration of an aqueous leaf extract (20.88-146.18 mg/kg) of A. altilis on mean arterial pressure and heart rate were recorded via cannulation of the carotid artery on anaesthetized normotensive Sprague-Dawley rats. Recordings of the contractile activity of the aortic rings to the extract (0.71-4.26 mg/mL) were studied using standard organ bath techniques. Inhibitions of human CYP3A4 and CYP2D6 enzyme activities were evaluated by means of a fluorometric assay in 96 well plates using heterologously expressed microsomes. RESULTS: A. altilis caused significant (p < 0.05) hypotensive and bradycardiac responses unaffected by atropine (2 mg/kg) and mepyramine (5 mg/kg), but attenuated by propranolol (1 mg/kg) and N(G)-nitro-L-arginine methyl ester (5 mg/kg). The extract (0.71-4.26 mg/mL) significantly (p < 0.05) relaxed phenylephrine (10⁻9-10⁻4 M) and 80 mM KCl-induced contractions in endothelium intact and denuded aortic rings; and caused a significant (p < 0.05) rightward shift of the Ca²âº dose-response curves in Ca²âº-free Kreb's solution. Moderate inhibitions of cytochrome P450s (CYP3A4 and CYP2D6) enzyme activities with IC50 values of 0.695 ± 0.187 and 0.512 ± 0.131 mg/mL, respectively, were produced. CONCLUSION: A. altilis exhibits negative chronotropic and hypotensive effects through α-adrenoceptor and Ca²âº channel antagonism. Drug adversity effects are unlikely if the aqueous leaf extract is consumed with other medications reliant on CYP3A4 and CYP2D6 metabolism. This study thus provides scientific evidence for the use of the breadfruit in the treatment of hypertension.

Gastric ulceration in diabetes mellitus: protective role of vitamin C.

The effect of vitamin C administration on gastric acid secretion and ulcer in diabetic rats was studied. Vitamin C (200 mg/kg b.w.) was administered to both streptozotocin-induced diabetic and control groups orally for 28 days. Gastric acid secretion was measured and ulcer was induced using ethanol. Histological changes were observed in the stomach. Basal and stimulated acid secretion in diabetic control rat was significantly (P < 0.01) decreased when compared to vitamin C-treated diabetic group and control. Administration of vitamin C significantly (P < 0.05) increased the histamine-stimulated gastric acid secretion in diabetics than control while reduction in gastric secretion by ranitidine was similar compared with control. Vitamin C treatment significantly (P < 0.05) reduced ulcer index in diabetic group and increased mucus weight when compared with diabetic group which was also confirmed with photomicrographs. The mean body weight of diabetic rats treated with vitamin C was comparable to the control. The blood glucose level was significantly (P < 0.01) reduced in diabetic group given vitamin C (8.9 ± 1.8 mMol/L) compared to the diabetic control (32.2 ± 2.1 g). It is concluded that vitamin C is beneficial in improving gastric acid secretion and protects against ulceration in streptozotocin-induced diabetes mellitus in rats due to its antioxidant potential.

Comparative analysis on the effect of Lycopersicon esculentum (tomato) in reducing cadmium, mercury and lead accumulation in liver.

SCOPE: L. esculentum (tomato) contain compounds with anti-oxidant and anti-inflammatory properties, able to synthesize metal chelating proteins. We examined the ability of fruit extract to protect against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. METHODS AND RESULTS: Rats were fed on tomato mixed with rat chow (10% w/w), while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Tomato was administered together with the metals (group 2), a week after exposure (group 3) or a week before metal exposure (group 4) for a period of six weeks. The metal accumulations in the liver were determined using AAS. There was a significant (P<0.05) increase in protection by tomato to Cd and Hg accumulation but not to Pb (P<0.05) in weeks 2 and 4 for groups 2 and 3. The protective ability was significantly (P<0.05) increased for Pb in group 4, but was less comparable to Cd and Hg. CONCLUSION: Tomato reduces uptake while enhancing the elimination of these metals in a time dependent manner. The highest hepatoprotective effect was to Cd followed by Hg and least to Pb. Its administration is beneficial in reducing heavy metal accumulation in the liver.

Comparative study on the efficacy of Allium sativum (garlic) in reducing some heavy metal accumulation in liver of wistar rats.

SCOPE: Heavy metals are known to cause damage through indirect oxidative effects. This study was undertaken to compare the therapeutic efficacy and protective ability of garlic extracts on reducing toxicity induced by mercury, lead and cadmium in the liver. METHODS AND RESULTS: Rats were fed with rat chow mixed with raw garlic (7% w/w) while mercury (10ppm), cadmium (200ppm) and lead (100ppm) were given in drinking water. Garlic was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or a week before heavy metal exposure (group 4) for 6weeks. The heavy metal accumulations in the liver were determined using AAS. The percentage protection showed a time-dependent effect and was significantly (P<0.01) higher for cadmium compared to mercury and lead-treated groups. Analysis between the groups showed that garlic treatment after exposure had a significantly (P<0.05) higher percentage protection when compared with other modes. CONCLUSION: These results suggest that garlic offered more hepatoprotective effect to cadmium followed by mercury and least protection to lead at the selected dose of each metal in this study through the processes of uptake, assimilation and elimination of these metals.

Intestinal Fluid and Glucose Transport in Wistar Rats following Chronic Consumption of Fresh or Oxidised Palm Oil Diet.

Chronic ingestion of thermoxidized palm oil causes functional derangement of various tissues. This study was therefore carried out to determine the effect of chronic ingestion of thermoxidized and fresh palm oil diets on intestinal fluid and glucose absorption in rats using the everted sac technique. Thirty Wistar rats were divided into three groups of 10 rats per group. The first group was the control and was fed on normal rat chow while the second (FPO) and third groups (TPO) were fed diet containing either fresh or thermoxidized palm oil (15% wt/wt) for 14 weeks. Villus height and crypt depth were measured. The gut fluid uptake and gut glucose uptake were significantly (P < .001) lower in the TPO group than those in the FPO and control groups, respectively. The villus height in the TPO was significantly (P < .01) lower than that in FPO and control. The villus depth in TPO was significantly (P < .05) higher than that in FPO and control groups, respectively. These results suggest that ingestion of thermoxidized palm oil and not fresh palm oil may lead to distortion in villus morphology with a concomitant malabsorption of fluid and glucose in rats due to its harmful free radicals.