Nigerian Journal of Physiological Sciences最新文献

Caffeine is the most widely consumed psychoactive drug in the world, ingested as natural components of chocolate, coffee and tea and as added components to soda and energy drinks. Here we assessed behavioural changes caused by chronic caffeine administration as well as morphological changes within specific regions of the adult mice brain: the hippocampus and amygdala. Twenty-four adult male albino mice were randomly divided into three groups. Caffeine was administered daily by gavage for 8 weeks at a dosage of 20 mg/kg for low dose (LD) group and 60 mg/kg for high dose (HD) group while the third group served as control (CNT). After the period of administration, neurobehavioural tasks were carried out; Morris water maze for learning and memory open field test and elevated plus maze test for anxiety. The mice were sacrificed; their brain tissues were harvested and processed for H&E, Cresyl violet and Golgi staining, and assessed qualitatively and quantitatively. Quantitative data from the neurobehavioural tests and neuronal cell counts were expressed as means ± standard errors of means and compared across the groups using analysis of variance (ANOVA). Significance was set at p< 0.05. Mice in the high dose group learnt faster and had significantly increased number of platform crossings in the Morris water maze test. There was, however, a slightly increased level of anxiety in the caffeine-treated mice, compared to controls. Histo-morphometric analysis revealed significantly increased number of pyramidal neurons in the hippocampus in the low dose group, but a decreased neuronal count in the amydala of the low dose and high dose groups compared to controls. The pyramidal neurons in the hippocampus of the caffeine-treated mice had increased apical dendritic length compared to the controls. Our findings strengthen the available data suggesting that prolonged caffeine intake improves cognition, and this process could be mediated by promoting the growth of dendrites and increased number of neurons. However, this is coupled with an increased tendency to be anxiogenic.

Metals are natural component of the ecosystem present throughout the layers of atmosphere; their abundant expression in the brain indicates their importance in the central nervous system (CNS). Within the brain tissue, their distribution is highly compartmentalized, the pattern of which is determined by their primary roles. Bio-imaging of the brain to reveal spatial distribution of metals within specific regions has provided a unique understanding of brain biochemistry and architecture, linking both the structures and the functions through several metal mediated activities. Bioavailability of essential trace metal is needed for normal brain function. However, disrupted metal homeostasis can influence several biochemical pathways in different fields of metabolism and cause characteristic neurological disorders with a typical disease process usually linked with aberrant metal accumulations. In this review we give a brief overview of roles of key essential metals (Iron, Copper and Zinc) including their molecular mechanisms and bio-distribution in the brain as well as their possible involvement in the pathogenesis of related neurodegenerative diseases. In addition, we also reviewed recent applications of Laser Ablation Inductively Couple Plasma Mass Spectrophotometry (LA-ICP-MS) in the detection of both toxic and essential metal dyshomeostasis in neuroscience research and other related brain diseases.

Astrocytes are small star-shaped glial cells that maintain normal human brain physiology including secretion of several active compounds and the formation of blood brain barrier. Reactive astrocytes support regenerating axons and also, actuate some genes responsible for the induction of synapse formation. In this study, the effect of aqueous extract of Telfairia occidentalis seeds on hippocampal astrogliosis was probed using scopolamine-induced Alzheimer's type cognitive dysfunction Wistar rats. Thirty Wistar rats weighed between 180-200g were randomly grouped into five designated A, B, C, D and E.  Each group contained six rats. Alzheimer's type cognitive dysfunction was induced in groups B to E by administering intraperitoneally, 1 mg/kg body weight of scopolamine for seven days before Donepezil and the aqueous extract of Telfairia occidentalis seeds for fourteen days. Twenty-four hours after the last administration, the animals were sacrificed; their brain tissues perfused and stained with glial fibrillary acidic protein (GFAP) dye. Results revealed prominently stained astrocytes with their processes intact (group A). Some densely stained numerous astrogliosis with hypertrophied fibres were noticed in group B. Group C demonstrated prominent astrocytes with hypertrophied fibres, group D, moderately stained astrogliosis with hypertrophied fibres while group E showed numerous astrocytes with prominent nuclei and hypertrophied fibres. In conclusion, there was reduced hippocampal astrogliosis mostly in group D treated with Telfairia occidentalis which may neutralize oxidative stress and enhanced learning and memory in the Wistar rats of the present study.

There is increased possibility that combined herbal constituents may interact to increase toxicity and lower efficacy. Ruzu herbal bitters (RHB) is a blend of extracts from Curculigo pilosa, Uvaria chamae, and Citrullus colocynthis, each of which has been shown to possess important bio-effects. There is anecdotal evidence for efficacy of RHB in neurological disorders; however, there are no data on possible neurotoxic effects of RHB. Using behavioural, biochemical and molecular indices as surrogates of neurotoxicity, this study therefore evaluated the nervous system effects of RHB. Twenty male Wistar rats were divided into two groups - a control group and RHB group (n=10). RHB (0.5ml/kg) was administered to the RHB group twice daily while control group took water (0.5ml/kg). Treatments lasted 6 weeks after which behavioural tests were carried out. Animals were subsequently sacrificed and the expression of serotonin transporter (SERT) and dopamine transporter (DAT) was determined in the striatum by immunofluorescence while specific activities of catalase, alkaline phosphatase and gamma glutamyltransferase were determined. In the elevated plus maze and light and dark box tests which are models of anxiety, animals treated with RHB showed significant anxiety compared to control. They also showed impaired locomotor activity in the open field and wire hang tests. The activity of catalase was significantly increased in the brain of the RHB treated rats while an increase in the expression of both DAT and SERT was observed in the striatum.

Thyroid hormones have been shown to promote the generation of reactive oxygen species (ROS), consumption of antioxidants, and induction of oxidative stress, which triggers the release of heat shock proteins (HSPs) and VEGF-dependent angiogenesis. The present study investigated the effect of altered thyroid states, hypothyroidism and hyperthyroidism on hepatic and renal functions, oxidative stress biomarkers, and hepatorenal expressions of HSP70, HSP90, and VEGF. Male Wistar rats were randomized into vehicle-treated control, carbimazole-induced hypothyroidism, or levothyroxine-induced hyperthyroidism. Altered thyroid states caused impaired hepatic and renal functions accompanied by elevated malondialdehyde and reduced glutathione content and superoxide dismutase and catalase activities in the hepatic and renal tissues. These derangements were associated with down-regulation of hepatic and renal HSP70 and HSP90 and upregulation of hepatic and renal VEGF expression. Findings of histopathological examinations of the hepatic and renal tissues align with the biochemical derangements observed.   This study reveals that dysthyroidism impairs hepatorenal function via induction of oxidative stress and modulation of HSP70/HSP90/VEGF signaling.

Pandemics have claimed an estimated 414 million lives from 165 AD to present, with COVID-19 pandemic killing close to 2 million people. The best counter for pandemics has been the use of vaccines, but before it is widely available, the best strategy is to avoid being infected. COVID-19 pandemic was met by behaviours and attitudes ranging from unbelief to fear of dying and stigmatisation of those who have contracted the virus or recovered from the disease. This study aimed to investigate the knowledge, attitudes, practices (KAP), fear and stigma of the populace towards COVID-19 from state to state. This research was a cross-sectional study carried out from April to October 2020. Data was obtained through a structured questionnaire distributed to 650 individuals. Respondents who participated were 591 (males n= 335 and females n= 256) and aged 18-60 years (mean age 30.25 ± 10.45 years, range 18-60) drawn from five states in the north-central region of Nigeria. The results show that 98.3% of participants believe that COVID-19 disease exists. Still, not everyone wears face masks, avoid crowded places, practice social distancing or follow the WHO-hand-washing technique as measures to curb the spread of the disease. Only 60.5% of the participants believe that lockdown is an effective measure to reduce transmission risk. 55.6% will stigmatise those who just recovered from the disease, 75.3% are afraid to visit high-risk areas as part of the protective measures, but only about 12% believe that every infected person will die. More males (28.3%) than females (17.6%) believe that taking herbs can cure the disease (P<0.01). All government and nongovernmental organizations must develop more awareness programs to win the battle against COVID-19 disease as the second wave is emerging.

Parkinson's disease (PD) and dementia with Lewy bodies have several commonalities including neurochemical, morphological and clinical features as well as widespread of cortical and limbic α-synuclein and amyloid-β pathologies. Thus, we evaluated the action of hesperidin on α-synuclein and amyloid-β-induced neurodegeneration in Drosophila melanogaster. The disease causing human Aβ peptide or α- synuclein was expressed respectively, in Elav-GAL4 (pan-neuronally) and dopaminergic neurons (ddc-GAL4) using the UAS-GAL4 system. Flies were either grown on food media supplemented with or without hesperidin (HSD) (1, 5, or 10mM). Behavioral assays were carried to investigate the effect of treatment on fecundity, larval motility, climbing ability and lifespan. Aβ>Elav or α-syn>DDC caused significant decrease in fecundity, larva contraction, motility, survival rate, and climbing activities in flies indicative of neurodegeneration. However, supplementation of flies' media with hesperidin (1mM, 5mM and 10mM) showed a dose-dependent increase in the number of line crosses in the egg laying, larva motility, climbing activity in comparison with flies grown on food media only. Conversely, supplementation of fly feed with HSD caused no significant change in lifespan. Findings from this experiment showed that hesperidin could be a potential neuroprotective agent in the amelioration of PD and AD pathogenesis.

This study evaluates the therapeutic potentials of selected antihypertensive drugs [valsartan, amlodipine, lisinopril and their fixed-dose combinations (amlodipine + lisinopril) and (valsartan + lisinopril)] in ameliorating trastuzumab (TZM)‑induced cardiac dysfunctions in experimental rats. After an ethical clearance for the study was obtained, in-bred young adult female Wistar rats were randomly allotted into 10 groups of 6 rats per group. Group I rats were treated with 10 ml/kg/day sterile water p.o. and 1 ml/kg/day sterile water i.p.; Group II, III and IV rats were orally treated with 5 mg/kg/day VAL and 1 ml/kg/day sterile water i.p., 0.25 mg/kg/day ADP and 1 ml/kg/day sterile water i.p., 0.035 mg/kg/day LSP and 1 ml/kg/day sterile water i.p., respectively. Group V rats were orally pretreated with 10 ml/kg/day of sterile water before i.p. 2.25 mg/kg/day of TZM. Groups VI-VIII rats were equally pretreated with 5 mg/kg/day VAL, 0.25 mg/kg/day ADP, and 0.035 mg/kg/day LSP before i.p. 2.25 mg/kg/day TZM treatment, respectively. Also, Groups IX and X rats were orally pretreated with the fixed-dose combinations of 0.25 mg/kg/day ADP + 0.035 mg/kg/day LSP in dissolved in sterile water and 5 mg/kg/day VAL + 0.035 mg/kg/day LSP before 2.25 mg/kg/day TZM treatment for 7 days. Blood pressure parameters [systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP)] and electrocardiogram (ECG) of the treated rats were measured using non-invasive procedures on days 1 and 7 of the experiment, following which the treated rats were sacrificed humanely under light inhaled diethyl ether and histopathological examination was conducted on all treated rat hearts. Results show that repeated TZM treatment significantly (p<0.05) raised SBP, DBP and MAP values from 115.0 ± 17.1 mmHg, 85.1 ± 15.1 mmHg     and      94.7 ± 15.5 mmHg, respectively on day 1      to 127.7 ± 27.8 mmHg, 87.4 ± 27.3 mmHg       and 100.5 ± 26.4 mmHg, respectively, on day 7. Oral pretreatments with VAL, ADP, LSP and their fixed-dose combinations significantly (p<0.05) attenuated increases in the SBP, DBP and MAP values with the most significant attenuation mediated by the fixed-dose VAL + LSP combination at the SBP, DBP and MAP values of 103.8 ± 20.6        mmHg, 65.5 ± 18.8 mmHg, and 77.9 ± 18.7 mmHg, respectively. TZM treatment also profoundly (p<0.05) prolonged the QT and corrected QT intervals from 85.0 ± 11.5 ms and         161.6 ± 20.3 ms, respectively, on day 1 to 110.2 ± 21.5 ms and 226.5 ± 41.5 ms, respectively, on day 7. However, these QT and corrected QT interval prolongations were effectively and profoundly attenuated by oral pretreatments with VAL, ADP, LSP and their fixed-dose combinations. In addition, TZM cardiotoxicity was characterized by marked vascular and cardiomyocyte congestion and coronary artery microthrombi formation. However, these histopathological changes were reversed with oral pretreatments with ADP, LSP, VAL and fixed

The hyperglycaemia of diabetes mellitus (DM) induces oxidative stress which damages the tissues. Glibenclamide, an oral hypoglycaemic drug used in the treatment of DM has associated side effects. Natural products are considered safe in the treatment of chronic diseases. Hibiscus sabdariffa (HS) is a plant that has demonstrated antidiabetic activity. We aimed to determine the potential benefits of co-administration of HS and glibenclamide in ameliorating oxidative stress in streptozotocin (STZ)-induced diabetic rats.  A total of 25 male albino Wistar rats were divided randomly into five groups: control (Non-DM), diabetic (DM), diabetic treated with 600µg/kg BW of glibenclamide (DM + GLIB), diabetic treated with 500mg/kg BW of HS (DM + HS), diabetic treated with both 600µg/kg BW of glibenclamide and 500mg/kg BW of HS (DM + GLIB + HS). The interventions were administered for a period of 28 days. The Non-DM rats were significantly heavier (p<0.01) compared to rats in the other treatment groups. Glibenclamide or HS alone and in combination, significantly lowered (p < 0.001) the final fasting blood glucose concentration of the rats in the respective treatment groups. HS and a combination of HS+ GLIB resulted in increased (p<0.05) serum activity of catalase, glutathione peroxidase and superoxide dismutase compared to the DM untreated rats.  The serum level of malondialdehyde was significantly lowered (p=0.000) in rats that received a combination of HS + GLIB compared to the DM untreated rats. Coadministration of HS + GLIB showed beneficial regeneration of islet-cells in the pancreas. Co-administration of HS + GLIB appears to be more beneficial in the treatment of DM and associated oxidative stress than when given as single agents. Thus, a case for their incorporation as a combined therapy for DM should be considered.

COVID-19 caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) enters the host cells through attachment to the Angiotensin Converting Enzyme-2 receptors (ACE-2) on the host cells. ACE-2 is known to affect renal functions, vasoconstriction and fluid homeostasis. Thus, the impact of SARS-CoV-2 infection on renal functional parameters is worth investigating. Plasma obtained from whole blood samples collected from newly diagnosed COVID-19 patients were analysed for albumin, urea, creatinine, Na, K, Cl and HCO3 using auto analysers. All newly diagnosed patients were immediately admitted for managed at the Infectious Disease Center, Olodo in Ibadan the capital of Oyo State, South Western Nigeria. The results obtained were evaluated to determine the frequency of derangements in the renal parameters of patients with the COVID-19 disease. It was observed that 57.1%, 37.8%, 32.7%, 28.1%, 18.7%, 17.8% and 3.4% of newly diagnosed COVID-19 patients had values of Cl, creatinine, albumin, Na, K, HCO3 and urea respectively outside the reference ranges. While 43.3%, 4.7%, 2.5%, 2.5%, 2.0%, 1.7% and 1.0% of COVID-19 patients had values of Cl, creatinine, Na, K, albumin, Urea and HCO3 respectively above the reference ranges. Of all admitted patients, 33.1%, 30.7%, 25.6%, 16.8%, 16.3%, 13.8% and 1.7% had creatinine, albumin, Na, HCO3, K, Cl and urea values respectively below reference ranges. The changes in renal function parameters of newly diagnosed COVID-19 patients portend that renal failure is imminent in poorly managed COVID-19 patients and this has immunopathology implications during SAR-COV-2 infection.