Nigerian Journal of Physiological Sciences最新文献

Tobacco, which is a product of Nicotiana tabacum, has nicotine as its principal phytochemical. Nicotine has been reported to be an addictive drug and the leading cause of tobacco addiction worldwide with consequent renal implications. Therefore, this study was conducted to investigate the effect of the aqueous extract of Nicotiana. tabacum on serum electrolytes, urea and creatinine levels as indices of renal function in male rats. A total of 18 male wistar rats weighing 140-230g were used for this study. The animals were randomly divided into three groups (A, B and C), containing 6 rats each. Group A served as control while Group B and C were orally administered sublethal doses of 20 and 30 mg/kg body weight of the Nicotiana. tabacum extract respectively once per day for three weeks. At the end of the experimental period, all the animals were sacrificed. Blood samples were collected for biochemical assay. The results showed a significant increase (p<0.05) in the serum concentration of sodium, potassium and urea levels of rats treated with the extract when compared with the control. However, serum concentrations of chloride, bicarbonate and creatinine showed no significant appreciable differences between the treated groups and the control group (p<0.05). In conclusion, the study showed that aqueous extract of Nicotiana tabacum is associated with renal dysfunction with consequent hypernatremia and hyperkalemia, and may also suggest impaired urea clearance by the kidneys in male wistar rats.

Background: Parkinson disease (PD) and Alzheimer's disease (AD) are progressive neurodegenerative disorders characterized by loss of selective neurons in discreet part of the brain. The peptide angiotensin II (Ang II) plays significant role in hippocampal and striatal neurons degeneration through the generation of reactive oxygen species. Blockade of the angiotensin converting enzyme or ATI receptors provides protection in animal models of neurodegenerative diseases. In the present study, the neuroprotective effect of captopril was investigated in Drosophila melanogaster model using the UAS-GAL4 system to express the synuclein and Aβ42 peptide in the flies' neurons.

Methods: The disease causing human Aβ42 peptide or α-syn was expressed pan-neuronally (elav-GAL4) or dopamine neuron (DDC-GAL4) using the UAS-GAL4 system. Flies were either grown in food media with or without captopril (1, 5, or 10µM). This was followed by fecundity, larva motility, negative geotaxis assay (climbing) and lifespan as a measure of neurodegeneration.

Results: Elav-Gal4

The present study was designed to investigate the effects of caffeine and adrenaline administration on memory and anxiety in male rats. Rats weighing about 140-200g were used for the study. They were divided into three groups (4 animals per group). Study groups 1; a,b,c,d were healthy rats administered normal saline, 5,10 and 15mg/kg bw caffeine intraperitoneally (i.p.), respectively for 6 weeks. Study groups 2; a,b,c,d administered normal saline, 0.1, 0.2 and 0.31mg/kg bw adrenaline (i.p.), respectively for 6 weeks. Study groups 3; a,b,c,d administered normal saline, 5mg/kg caffeine (i.p.) + 0.1mg/kg adrenaline (i.p.), 10mg/kg Caffeine (i.p.) + 0.2mg/kg Adrenaline (i.p.) and 15mg/kg Caffeine (i.p.) + 0.3mg/kg Adrenaline (i.p.) respectively for 6 weeks. The result showed no significant difference in spatial memory across all animals in study groups 1: b,c,d when compared to control (a). Study groups 2: (b, c) showed increase in spatial memory when compared to control (a). 2(d) showed a significant (p<0.05) decrease. Study groups 3: b, c, d showed no significant difference in spatial memory when compared to control (a). Study groups 1: b, c showed significant (p<0.05) reduction in duration for the short and long term memory test when compared to control. Study groups 2 showed reduction in duration for both the long and short term memory test when compared to control Study groups 3 no significant (p<0.05) difference in short and long term memory test across all animals in the group. It was also observed that adrenaline enhanced short and long term memory and only high dose of adrenaline distorted spatial memory. Study groups 1; (b,c) showed significant (p<0.05) increase in the number of entries to the open arm of the elevated plus maze when compared to control (a). Study groups 2; (b), showed significant (p<0.05) increase in the frequencies of entries to the closed arm of the elevated plus maze when compared to control (a). Study groups 2; (d), showed a significant (p<0.05) decrease in the frequency of entries to the open and closed arm when compared to control (a). The study revealed that co- administration of caffeine and adrenaline led to elevation of mood, increased activity and reduction of anxiety in Wistar rats. In addition, it was observed that only high dose of adrenaline increased anxiety. It was also observed that caffeine and adrenaline enhanced short and long term memory and only high dose of adrenaline distorted spatial memory.

Maternal lifestyle has been implicated as a predisposing factor in the development of metabolic disorders in adulthood. This lifestyle includes the immediate environment, physical activity and nutrition. Maternal nutrition has direct influence on the developmental programming through biochemical alterations and can lead to modifications in the fetal genome through epigenetic mechanisms. Imbalance in basic micro or macro nutrients due to famine or food deficiency during delicate gestational periods can lead to onset of metabolic syndrome including obesity. A major example is the Dutch famine which led to a serious metabolic disorder in adulthood of affected infants. Notably due to gene variants, individualized responses to nutritional deficiencies are unconventional, therefore intensifying the need to study nutritional genomics during fetal programming. Epigenetic mechanisms can cause hereditary changes without changing the DNA sequence; the major mechanisms include small non-coding RNAs, histone modifications and most stable of all is DNA methylation. The significance association between obesity and DNA methylation is through regulation of genes implicated in lipid and glucose metabolism either directly or indirectly by hypomethylation or hypermethylation. Examples include CPT1A, APOA2, ADRB3 and POMC. Any maternal exposure to malnutrition or overnutrition that can affect genes regulating major metabolic pathways in the fetus, will eventually cause underlying changes that can predispose or cause the onset of metabolic disorder in adulthood. In this review, we examined the interaction between nutrition during gestation and epigenetic programming of metabolic syndrome.

Alzheimer's disease (AD) is the most common cause of dementia that affects one patient every seven seconds, with over 35 million people currently affected worldwide. The aim of the study was to investigate the modulation of memory and neurochemical responses by resveratrol and environmental enrichment (EE) in aluminium chloride (AlCl3) model of Alzheimer's disease in mice. Male mice used for the study were divided into nine groups, of seven animals each. Group I (negative control): 0.2 ml normal saline/kg, Group II: 0.2 ml CMC/kg. Group III: resveratrol (200 mg/kg/), Group IV: CMC and kept in EE, Group V: AlCl3 at dose of 50 mg/kg, Group VI: resveratrol at dose of 200 mg/kg and kept in EE, Group VII: AlCl3 (50 mg/kg) + resveratrol (200 mg/kg), Group VIII: AlCl3 (50 mg/kg) and kept in EE, Group IX: AlCl3 (50 mg/kg) + resveratrol (200 mg/kg) and kept in enriched environment. All treatments were oral and lasted for 8 weeks. Assessments of memory was carried out before treatment, and at weeks 4 and 8, after the first treatment. The mice were sacrificed and hippocampal samples collected for neurochemical analysis. The findings of the study suggest that AlCl3 induced contextual fear memory deficit over time (p < 0.05), which was improved by resveratrol. Both Aβ and Nrf2 significantly (p < 0.05) increased in AlCl3 + EE + resveratrol group. In conclusion, Individual treatment with either resveratrol or EE improved memory over the combined treatment in AlCl3 model of AD by decreasing Aβ protein concentration.

This study was designed to investigate the modulatory role of Luteolin (Lut), a flavonoid phytochemical, on haemodynamic parameters and the potential mechanisms involving renal Angiotensin II (AT2R) and Mineralocorticoid (MCR) receptors in renal toxicity induced by co-exposure to Diclofenac (Dcf) and sodium fluoride (NaF) in rats.Male Wistar rats were administered with either vehicle (control), Dcf only (9 mg/kg orally) or concurrently with NaF (300 ppm in drinking water). Other groups were treated with LutA (100 mg/kg) or LutB (200 mg/kg) along with Dcf and NaF exposures. All treatments lasted 8 days, following which blood pressure indices were measured using tail-cuff plethysmography. Renal expressions of AT2R and MCR were studied with immunohistochemistry, while biomarkers of oxidative and antioxidant status were also measured in the kidneys. Systolic, diastolic and mean arterial pressures were significantly (p<0.05) reduced in Dcf-treated rats, compared to control values. However, co-treatment with NaF or Lut restored these parameters. While the expression of AT2R and MCR was high in the Dcf and Dcf+NaF groups, treatment with Lut caused obvious reduction in the renal expression of these receptors. Increased lipid peroxidation (Malondialdehyde) and protein oxidation (protein carbonyls) with a lowering of reduced glutathione levels contributed to the renal toxicity of Dcf, and these were significantly ameliorated in Lut-treated rats. In conclusion, the preservation of haemodynamic indices by Lutin the experimental ratsprobably included mechanisms involving down-regulation of renal expressions of AT2R and MCR, reduction of oxidative stress and an improvement of renal antioxidant status.

Diabetes mellitus is one of the most widespread diseases affecting the world's population causing substantial morbidity, mortality and long-term complications. This study was designed to investigate possible hypoglycemic, hypolipidemic and antioxidant effect of ethanolic stem bark extract of Anacardium occidentale in streptozotocin (STZ)-induced diabetic rats. Twenty-eight STZ (60 mg/kg body weight)-induced diabetic, male albino rats were randomly distributed into Groups II-V (7 rats each) and orally administered with water, metformin (14.2 mg/kg), 200 mg/kg Anacardium occidentale extract and 400 mg/kg Anacardium occidentale extract respectively daily for 15 days. Group I rats were untreated with STZ and serves as control all under the same sham handling. Blood samples were taken for measurement of fasting blood glucose (FBG) and lipid profile. Liver and kidney tissue samples were taken for determination of glycemic indices (glucose and glycogen), as well as redox status markers such as malondialdehyde (MDA), total glutathione (GSH), activities of superoxide dismutase (SOD) and glutathione-s-transferase (GST). Results showed that treatment with 200 and 400 mg/kg Anacardium occidentale stem bark extract reversed hyperglycemia and hyperlipidemia induced by STZ similar to what was observed with the standard drug, metformin. Similarly, both extract concentration produced a significant reduction in MDA while the activity of SOD and GST, as well as concentration of GSH were elevated. This study suggested that ethanolic stem bark extract of Anacardium occidentale at 200 and 400 mg/kg can ameliorate diabetes and its associated complications via its hypoglycemic, hypolipidemic, antioxidant and free radical scavenging properties.

Hibiscus sabdariffa (HS) has gained attention as an anti-hypertensive agent. In the present study, we hypothesized that anthocyanins from HS may attenuate salt-induced hypertension in rats by suppressing the components of renin-angiotensin-aldoslestrone system (RAAS). Hypertension was induced in the rats by adding 8% NaCl in their diet for six weeks. Wistar rats (n=5 each) were randomly divided into seven groups. Group 1 was the normentensive control group and was fed with normal rat chew and water ad libitum; groups 2 and 3 served as hypertensive control (negative untreated and positive treated with captopril 30mg/kg respectively); groups 4, 5, and 6 served as treatment groups and were administered with graded doses of anthocyanins( 50, 100, 200mg/kg respectively) while group 7 received both 100mg anthocyanins and 30mg captopril per day for 4 weeks. Using HPLC, anthocyanins were isolated from HS calyx following standard protocol. Anthocyanins significantly (p<0.05) reduced blood pressure and heart rate in hypertensive rats in a dose dependent manner. The blood pressure reduction by anthocyanins was associated with a reduction in serum ACE and plasma aldosterone in the hypertensive rats. The effects of anthocyanins on blood pressure and on biomarkers of RAAS were similar to those of captopril, a reference anti-hypertensive drug. The results suggest that anthocyanins exerts a significant (p<0.05) anti-hypertensive potency on rats, probably mediated by the reduction in components of the RAAS. Keywords: hypertension, anthocyanins, renin, aldosterone, rats.

Impaired male reproductive function is a major complication associated with diabetes mellitus (DM). Whether or not insulin, when co-administered with zinc will reverse or ameliorate reproductive dysfunction in male diabetics is not known. This study thus sought to establish if co-administration of insulin and zinc reverses or ameliorates male reproductive dysfunction in DM better than either insulin or zinc. Five (5) normal and twenty (20) diabetic sexually mature rats were assigned into five groups of five animals each. Group A consisted of normal rats and had access to only food and water. Group B consisted of diabetic animals with no treatment and served as DM control. Groups C and D consisted of diabetic animals and received insulin and zinc respectively. Group E consisted of diabetic animals and received both insulin and zinc. All diabetic animals had free access to food and water. Insulin in all cases was given subcutaneously twice daily in the morning and evening at 1 unit and 4 units respectively. Zinc (10mg/kg) was given orally once daily. Treatments in all cases commenced two weeks after DM was confirmed. The treatment lasted ten days. Samples were thereafter collected for analyses. DM decreased sperm count, sperm motility, sperm viability, normal sperm cells, semen pH, serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone, while increasing sperm cells with defective tails. DM also impaired testicular morphology. Insulin and zinc co-administration improved sperm viability, sertoli cell count, Johnsen's score, serum FSH, LH and testosterone. Co-administration also improved semen pH towards normal. Insulin or zinc ameliorated several aspects of DM-induced male sexual dysfunction. However, the co-administration of insulin and zinc provided better results.