Neuropathological profile of the African Giant Rat brain (Cricetomys gambianus) after natural exposure to heavy metal environmental pollution in the Nigerian Niger Delta

Pollution by heavy metals is a threat to public health because of the adverse effects on multiple organ systems including the brain. Here, we used the African giant rat (AGR) as a novel sentinel host to assess the effect of heavy metal accumulation and consequential neuropathology upon the brain. For this study, AGR were collected from distinct geographical regions of Nigeria: the rain forest region of south-west Nigeria (Ibadan), the central north of Nigeria (Abuja), and in oil-polluted areas of south Nigeria (Port-Harcourt). We found that zinc, copper, and iron were the major heavy metals that accumulated in the brain and serum of sentinel AGR, with the level of iron highest in animals from Port-Harcourt and least in animals from Abuja. Brain pathology, determined by immunohistochemistry markers of inflammation and oxidative stress, was most severe in animals from Port Harcourt followed by those from Abuja and those from Ibadan were the least affected. The brain pathologies were characterized by elevated brain advanced oxidation protein product (AOPP) levels, neuronal depletion in the prefrontal cortex, severe reactive astrogliosis in the hippocampus and cerebellar white matter, demyelination in the subcortical white matter and cerebellar white matter, and tauopathies. Selective vulnerabilities of different brain regions to heavy metal pollution in the AGR collected from the different regions of the country were evident. In conclusion, we propose that neuropathologies associated with redox dyshomeostasis because of environmental pollution may be localized and contextual, even in a heavily polluted environment. This novel study also highlights African giant rats as suitable epidemiological sentinels for use in ecotoxicological studies.

Antioxidant activity enhancement and oxidative damage inhibition by Lagenaria breviflora fruit and Xanthosoma sagittifolium corm in hypertensive Wistar rats

Cardiovascular diseases are the leading causes of mortality in the world today with hypertension being the major clinical presentation of these diseases. This study assessed the anti-hypertensive effects of Lagenaria breviflora whole fruit and Xanthsoma  sagittifolium corms in experimentally inudced hypertensive Wistar rats. The ability of the plants to ameliorate oxidative damage accompanying hypertension was evaluated using changes in oxidative stress markers as well as monitoring of cardiovascular parameters. Hypertension was induced by intraperitoneal injection of DOCA salt twice weekly and daily inclusion of NaCl (1%) in drinking water. Methanol extracts of L.breviflora or X. sagittifolium was administered to hypertensive rats for 35 days and the outcome was compared to hypertensive rats administred with lisinopril or hydrochlorothiazide and a group of normotensive rats (control). Systolic, diastolic and mean arterial pressures were determined on day 34 and blood sample collected on day 35. The rats were thereafter humanely sacrificed, and organs were harvested. This study showed that the extracts lowered blood pressure, free protein thiols but increased toal protein, gluthathione peroxidase, reduced glutathione, glutathione S-transferase, catalase and nitric oxide in the heart, kidney and liver compared to untreated hypertensive rats. However, malondialdehyde levels and hydrogen peroxide activities were reduced. L. breviflora fruit and X. sagittifloium corm exhibited antihypertensive properties and ameliorate oxidative damage associated with hypertension by enhancing the antioxidant defense sysyem and inhibiting generation of free radicals.

Ameliorative effects of glycine on cobalt chloride-induced hepato-renal toxicity in rats

BACKGROUND

The important roles of liver and kidney in the elimination of injurious chemicals make them highly susceptible to the noxious activities of various toxicants including cobalt chloride (CoCl₂ ). This study was designed to investigate the role of glycine in the mitigation of hepato-renal toxicities associated with CoCl₂ exposure.

METHODS

Forty-two (42) male rats were grouped as Control; (CoCl₂ ; 300 ppm); CoCl₂  + Glycine (50 mg/kg); CoCl₂  + Glycine (100 mg/kg); Glycine (50 mg/kg); and Glycine (100 mg/kg). The markers of hepatic and renal damage, oxidative stress, the antioxidant defense system, histopathology, and immunohistochemical localization of neutrophil gelatinase associated lipocalin (NGAL) and renal podocin were evaluated.

RESULTS

Glycine significantly reduced the markers of oxidative stress (malondialdehyde content and H₂ O₂ generation), liver function tests (ALT, AST, and ALP), markers of renal function (creatinine and BUN), and decreased the expression of neutrophil gelatinase-associated lipocalin (NGAL) and podocin compared with rats exposed to CoCl₂ toxicity without glycine treatment. Histopathology lesions including patchy tubular epithelial necrosis, tubular epithelial degeneration and periglomerular inflammation in renal tissues, and severe portal hepatocellular necrosis, inflammation, and duct hyperplasia were observed in hepatic tissues of rats exposed to CoCl₂ toxicity, but were mild to absent in glycine-treated rats.

CONCLUSION

The results of this study clearly demonstrate protective effects of glycine against CoCl₂ -induced tissue injuries and derangement of physiological activities of the hepatic and renal systems in rats. The protective effects are mediated via augmentation of total antioxidant capacity and upregulation of NGAL and podocin expression.

Naringin administration mitigates oxidative stress, anemia, and hypertension in lead acetate-induced cardio-renal dysfunction in cockerel chicks

Lead is one of the major pollutants that is harmful to both animals and humans. It is found in every aspect of the environment such as the air, water, and soil. This pollutant affects both wild and domestic birds. Naringin has an active principle called flavonoid that has been found to have medicinal properties, mostly because of its antioxidant and metal chelating properties. This study was carried out to investigate the protective effect of naringin as an antioxidant against lead-induced anemia, cardio and nephrotoxicity, and hypertension. This study also aimed at elucidating the use of naringin as a heavy metal binder in poultry feed. Thirty-six cockerel chicks were used for this study, and randomly grouped into six groups per group; group A served as the control, group B received Pb-only (300 ppm), group C (Pb and naringin; 80 mg/kg), group D (Pb and naringin; 160 mg/kg), group E (naringin 80 mg/kg), and group F (naringin 160 mg/kg), respectively, for 8 weeks. Lead (Pb) was administered via drinking water, while naringin was administered via oral gavage. Lead acetate intoxication precipitated anemia as indicated by significant reductions in the values of PCV, RBC, and Hb concentration in lead-treated chicks when compared with the controls. Also, lead administration induced hypertension together with increased oxidative stress, depletion of the antioxidant defense system, reduced nitric oxide production, and an increase in high blood pressure. Immunohistochemistry indicated high expressions of cardiac troponin, renal angiotensin-converting enzymes, and renal neutrophil gelatinase-associated lipocalin. Treatment with naringin corrected anemia, reduced oxidative stress, improved antioxidant system, reduced high blood pressure, and offered protection against lead acetate-induced cardio-renal dysfunction in cockerel chicks. We recommend that naringin should be incorporated poultry feeds as a metal binder.

Naringin abrogates angiotensin-converting enzyme (ACE) activity and podocin signalling pathway in cobalt chloride-induced nephrotoxicity and hypertension

PurposeThe persistent and alarming rates of increase in cardiovascular and renal diseases caused by chemicals such as cobalt chloride (CoCl₂) in mammalian tissues have led to the use of various drugs for the treatment of these diseases. This study aims at evaluating the nephron-protective action of Naringin (NAR), a metal-chelating antioxidant against CoCl₂-induced hypertension and nephrotoxicity.MethodsForty-two male Wistar rats were randomly distributed to seven rats of six groups and classified into Group A (Control), Group B (300 part per million; ppm CoCl₂), Group C (300 ppm CoCl₂ + 80 mg/kg NAR), Group D (300 ppm CoCl₂ + 160 mg/kg NAR), Group E (80 mg/kg NAR), and Group F (160 mg/kg NAR). NAR and CoCl₂ were administered via oral gavage for seven days. Biomarkers of renal damage, oxidative stress, antioxidant status, blood pressure parameters, immunohistochemistry of renal angiotensin-converting enzyme and podocin were determined.ResultsCobalt chloride intoxication precipitated hypertension, renal damage, and oxidative stress. Immunohistochemistry revealed higher expression of angiotensin-converting enzyme (ACE) and podocin in rats administered only CoCl₂.ConclusionTaken together, the antioxidant and metal-chelating action of Naringin administration against cobalt chloride-induced renal damage and hypertension could be through abrogation of angiotensin-converting enzyme and podocin signalling pathway.

L-arginine and lisinopril supplementation protects against sodium fluoride-induced nephrotoxicity and hypertension by suppressing mineralocorticoid receptor and angiotensin-converting enzyme 3 activity

Sodium fluoride (NaF) is one of the neglected environmental toxicants that has continued to silently cause toxicity to both humans and animals. NaF is universally present in water, soil, and atmosphere. The persistent and alarming rate of increase in cardiovascular and renal diseases caused by chemicals such as NaF in mammalian tissues has led to the use of various drugs for the treatment of these diseases. The present study aimed at evaluating the renoprotective and antihypertensive effects of L-arginine against NaF-induced nephrotoxicity. Thirty male Wistar rats (150-180 g) were used in this study. The rats were randomly divided into five groups of six rats each as follows: Control, NaF (300 ppm), NaF + L-arginine (100 mg/kg), NaF + L-arginine (200 mg/kg), and NaF + lisinopril (10 mg/kg). Histopathological examination and immunohistochemistry of renal angiotensin-converting enzyme (ACE) and mineralocorticoid receptor (MCR) were performed. Markers of renal damage, oxidative stress, antioxidant defense system, and blood pressure parameters were determined. L-arginine and lisinopril significantly (P < 0.05) ameliorated the hypertensive effects of NaF. The systolic, diastolic, and mean arterial blood pressure of the treated groups were significantly (P < 0.05) reduced compared with the hypertensive group. This finding was concurrent with significantly increased serum bioavailability of nitric oxide in the hypertensive rats treated with L-arginine and lisinopril. Also, there was a significant reduction in the level of blood urea nitrogen and creatinine of hypertensive rats treated with L-arginine and lisinopril. There was a significant (P < 0.05) reduction in markers of oxidative stress such as malondialdehyde and protein carbonyl and concurrent increase in the levels of antioxidant enzymes in the kidney of hypertensive rats treated with L-arginine and lisinopril. The results of this study suggest that L-arginine and lisinopril normalized blood pressure, reduced oxidative stress, and the expression of renal ACE and mineralocorticoid receptor, and improved nitric oxide production. Thus, L-arginine holds promise as a potential therapy against hypertension and renal damage.

Leaf extract of Anacardium occidentale ameliorates biomarkers of neuroinflammation, memory loss, and neurobehavioral deficit in N(ω)-nitro-L-arginine methyl ester (L-NAME) treated rats

PURPOSE

Anacardium occidentale commonly known as Cashew is a plant that is widely used in African traditional medicine. It is endowed with phytochemical constituents that are responsible for its medicinal properties.

METHODS

Twenty-five male Wistar rats were grouped as follows: Control (Group A), Group B (L-NAME 40 mg/kg), Group C (100 mg/kg Anacardium occidentale extract plus 40 mg/kg L-NAME), Group D (200 mg/kg extract plus 40 mg/kg L-NAME) and Group E (10 mg/kg of Lisinopril plus 40 mg/kg L-NAME). The animals were treated with oral administration of either the extracts or Lisnopril daily for 4 weeks. Neuro-behavioural tests such as the Morris Water Maze and Hanging Wire Grip tests were carried out to evaluate memory/spatial learning and muscular strength, respectively. Makers of oxidative stress, antioxidant enzymes and immunohistochemical staining of Glial Fibrillary Acidic Protein and Ionised Calcium Binding Adaptor molecule 1 were assessed.

RESULTS

L-NAME administration caused significant increases in biomarkers of oxidative stress, decreased antioxidant status, acetylcholinesterase activity, altered neuro-behavioural changes, astrocytosis, and microgliosis. However, Anacardium occidentale reversed exaggerated oxidative stress biomarkers and improved neuro-behavioural changes.

CONCLUSIONS

Combining all, Anacardium occidentale enhanced brain antioxidant defence status, improved memory and muscular strength, thus, suggesting the neuroprotective properties of Anacardium occidentale.

Supplementation of antihypertensive drug regimen with vitamin E ameliorates alterations of primary haemodynamic parameters and total antioxidant capacity in ovariectomised rats

OBJECTIVES

Ovariectomy induces heightened response to vasoconstrictors, alters vasorelaxation and consequently causes hypertension due to increased oxidative stress in rats.

METHODS

This study evaluated the ameliorative effects of ramipril and vitamin E, on primary haemodynamic parameters and cardiac antioxidant defence status, in ovariectomised rats using 64 adult female rats of the Wistar strain randomly divided as follows: Control (sham); Ovariectomised (OVX); OVX plus Ramipril; OVX plus vitamin E; and OVX plus Ramipril plus vitamin E.

RESULTS

The plasma level of oestrogen was significantly lower (p<0.05), in the ovariectomised rats compared with the sham. The systolic, diastolic and mean arterial blood pressure of ovariectomised rats increased significantly (p<0.05), but the alteration was significantly reduced by the administration of ramipril alone or in combination with vitamin E. Significant decrease (p<0.05) was observed in the serum level of nitric oxide in OVX group compared with Sham. Also, analysed markers of oxidative stress: Malondialdehyde (MDA) contents and hydrogen peroxide (H2O2) generated decreased significantly (p<0.05), but systemic antioxidants: reduced glutathione (GSH) contents; glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities increased significantly (p<0.05) in the ovariectomised rats treated with ramipril and vitamin E compared with untreated ovariectomised rats. The study concludes that alteration, in the primary haemodynamic parameters, associated with ovariectomy in rats is potently ameliorated by co-administration of the antihypertensive drug ramipril and vitamin E.

CONCLUSIONS

The supplementation of antihypertensive regimen with antioxidants such as vitamin E in the treatment of hypertension is therefore justifiable especially in ovariectomised or hypogonadal patients.

Antihypertensive action of Launaea taraxacifolia and its molecular mechanism of action

Launaea taraxacifolia has been traditionally used for the management of conditions such as cardiovascular, respiratory, and metabolic diseases. High blood pressure was established by oral administration of L-Nitro Arginine Methyl Ester (L-NAME) a non-selective inhibitor of endothelial nitric oxide synthase (eNOS). The antihypertensive action of the methanol leaf extract of L. taraxacifolia was examined. Fifty male Wistar rats were divided into 5 groups of 10 animals per group: Group A (Distilled water), Group B (Hypertensive rats; 40mg/kg L-NAME), Group C (Hypertensive rats plus 100mg/kg extract), Group D (Hypertensive rats plus 200 mg/kg extract) and Group E (Hypertensive rats plus 10mg/kg of Lisinopril). The treatments were orally administered for five weeks. Haemodynamic parameters, urinalysis, indices of oxidative stress and immunohistochemistry were determined. Findings from this study showed that blood pressure parameters, urinary sodium and indices of oxidative stress increased significantly while In-vivo antioxidant defence systems decreased significantly in hypertensive rats. Immunohistochemistry revealed significant increases in expressions of mineralocorticoid receptor, angiotensin converting enzyme activity and kidney injury molecule-1 in kidney of hypertensive rats. Treatment with Launeae taraxacifolia normalized blood pressure parameters, urinary sodium, oxidative stress indices, antioxidant defence system, and serum nitric oxide bioavailability.

Impacts of cadmium on male fertility: Lessons learnt so far

Cadmium (Cd) is one of the most dangerous heavy metals in the world. Globally, toxicities associated with cadmium and its attendant negative impact on humans and animals cannot be under-estimated. Cd is a heavy metal, and people are exposed to it through contaminated foods and smoking. Cd exerts its deleterious impacts on the testes (male reproductive system) by inducing oxidative stress, spermatogenic cells apoptosis, testicular inflammation, decreasing androgenic and sperm cell functions, disrupting ionic homeostasis, pathways and epigenetic gene regulation, damaging vascular endothelium and blood testes barrier. In association with other industrial by-products, Cd has been incriminated for the recent decline of male fertility rate seen in both man and animals. Understanding the processes involved in Cd-induced testicular toxicity is vital for the innovation of techniques that will help ameliorate infertility in males. In this review, we summed up recent studies on the processes of testicular toxicity and male infertility due to Cd exposure. Also, the usage of different compounds including phytochemicals, and plant extracts to manage Cd reprotoxicity will be reviewed.

Infused aqueous curry tea extracts ameliorate Nω -Nitro-L-Arginine Methyl Ester-induced liver dysfunction in male albino Wistar rats

BACKGROUND

Murraya koenigii (L.) Spreng. (Rutaceae) has been reported to positively affect liver function. However, the effect of M. koenigii leaves on N^ω -Nitro-L-Arginine Methyl Ester (L-NAME) induced liver dysfunction is unknown. The aim of the present study was therefore to investigate the effect of M.koenigii leaves as tea on L-NAME induced liver dysfunction.

METHODS

Two variants of curry tea were formulated; one was formulated entirely from leaves of M. koenigii, the other was formulated with thaumatin-rich aril obtained from seeds of Thaumatococcus danielii (Benn.) Benth. (Marantaceae). Group I animals served as control and were untreated. Groups II and V animals were administered curry tea (CT). Group III and VI animals received curry-thaumatin tea (CTT). Concurrently, L-NAME (40 mg/kg) was administered to groups IV-VI respectively for 21 days. Blood and liver samples were collected at the end of the study for biochemical, histological, and immunohistochemical analysis.

RESULTS

L-NAME induced liver dysfunction evidenced by liver histology, increased activities of ALT, AST, hyperlipidemia, hepatic oxidative stress and increased hepatic NF-kB expression. Administration of CT and CTT ameliorated the L-NAME induced liver dysfunction evidenced by liver histology, increased NO hepatic bioavailability, reduced activity of ALT and AST, increased hepatic antioxidant system and decreased hepatic NF-kB expression. Thaumatin taste/flavor enhancer did not significantly reduce or potentiate the hepatoprotective, antioxidant and anti-lipidemic property of aqueous curry tea extracts in rats.

CONCLUSION

L-NAME impaired liver function in rats. CT and CTT interfered with the ability of L-NAME to inhibit NO synthesis which was associated with ameliorated hepatic dysfunction.

PRACTICAL APPLICATIONS

The study reports that non-selective inhibition of nitric oxide by L-NAME in rats impairs liver function and formulated curry tea types interfered with the ability of L-NAME to inhibit NO synthesis which was associated with ameliorated hepatic dysfunction in rats.

Clofibrate, a Peroxisome Proliferator-Activated Receptor-Alpha (PPARα) Agonist, and Its Molecular Mechanisms of Action against Sodium Fluoride-Induced Toxicity

Sodium fluoride (NaF) is one of the neglected environmental pollutants. It is ubiquitously found in the soil, water, and environment. Interestingly, fluoride has been extensively utilized for prevention of dental caries and tartar formation, and may be added to mouthwash, mouth rinse, and toothpastes. This study is aimed at mitigating fluoride-induced hypertension and nephrotoxicity with clofibrate, a peroxisome proliferator-activated receptor-alpha (PPARα) agonist. For this study, forty male Wistar rats were used and randomly grouped into ten rats per group, control, sodium fluoride (NaF; 300 ppm) only, NaF plus clofibrate (250 mg/kg) and NaF plus lisinopril (10 mg/kg), respectively, for 7 days. The administration of NaF was by drinking water ad libitum, while clofibrate and lisinopril were administered by oral gavage. Administration of NaF induced hypertension, and was accompanied with exaggerated oxidative stress; depletion of antioxidant defence system; reduced nitric oxide production; increased systolic, diastolic and mean arterial pressure; activation of angiotensin-converting enzyme activity and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB); and testicular apoptosis. Treatment of rats with clofibrate reduced oxidative stress, improved antioxidant status, lowered high blood pressure through the inhibition of angiotensin-converting enzyme activity, mineralocorticoid receptor over-activation, and abrogated testicular apoptosis. Taken together, clofibrate could offer exceptional therapeutic benefit in mitigating toxicity associated with sodium fluoride.

The therapeutic potential of the novel angiotensin-converting enzyme 2 in the treatment of coronavirus disease-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of coronavirus disease 2019 (COVID-19). This virus has become a global pandemic with unprecedented mortality and morbidity along with attendant financial and economic crises. Furthermore, COVID-19 can easily be transmitted regardless of religion, race, sex, or status. Globally, high hospitalization rates of COVID-19 patients have been reported, and billions of dollars have been spent to contain the pandemic. Angiotensin-converting enzyme (ACE) 2 is a receptor of SARS-CoV-2, which has a significant role in the entry of the virus into the host cell. ACE2 is highly expressed in the type II alveolar cells of the lungs, upper esophagus, stratified epithelial cells, and other tissues in the body. The diminished expressions of ACE2 have been associated with hypertension, arteriosclerosis, heart failure, chronic kidney disease, and immune system dysregulation. Overall, the potential drug candidates that could serve as ACE2 activators or enhance the expression of ACE2 in a disease state, such as COVID-19, hold considerable promise in mitigating the COVID-19 pandemic. This study reviews the therapeutic potential and pharmacological benefits of the novel ACE2 in the management of COVID-19 using search engines, such as Google, Scopus, PubMed, and PubMed Central.

Luteolin mitigates potassium dichromate-induced nephrotoxicity, cardiotoxicity and genotoxicity through modulation of Kim-1/Nrf2 signaling pathways

Environmental and occupational exposure to chromium compounds has become potential aetiologic agent for kidney disease with excessive generation of free radicals, apoptosis, and inflammatory. These pathophysiologic mechanisms of potassium dichromate (K₂ Cr₂ O₇ ) have been well correlated with nephrotoxicity and cardiotoxicity. The cardioprotective and nephroprotective effects of Luteolin, a known potent antioxidant were evaluated in this study with 40 healthy rats in four experimental groups: Group A (normal saline), Groups B (30 mg/kg K₂ Cr₂ O₇ ), Group C (Luteolin 100 mg/kg and K₂ Cr₂ O₇ 30 mg/kg), and Group D (Luteolin 200 mg/kg and K₂ Cr₂ O₇ 30 mg/kg), respectively. Markers of antioxidant defense system, oxidative stress, blood pressure and micronucleated polychromatic erythrocytes (MnPEs), immunohistochemistry of Kidney, injury molecule (Kim-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and cardiac troponin I were determined. Administration of K₂ Cr₂ O₇ increased blood pressure parameters in systolic, diastolic and mean arterial blood pressures, markers of oxidative stress, and frequency of micronucleated polychromatic erythrocytes, together with reduction in serum nitric oxide level. Renal Kim-1 and cardiac troponin I expressions were higher, but lower expressions of renal and cardiac Nrf2 were recorded with immunohistochemical analysis. Pre-treatment with Luteolin restored blood pressure parameters, with concomitant reduction in oxidative stress indicators, augmented antioxidant mechanisms and serum Nitric oxide level, lowered the expressions of Kim-1, cardiac troponin I and up-regulated of both cardiac and renal Nrf2, reduced the frequency of micronucleated polychromatic erythrocytes. Taken together, this study therefore demonstrates the cardioprotective, nephro protective and antigenotoxic effects of Luteolin through antioxidantive and radical scavenging mechanisms.

Chrysophyllum albidum fruit ethanol extract ameliorates hyperglycaemia and elevated blood pressure in streptozotocin-induced diabetic rats through modulation of oxidative stress, NF-κB and PPAR-γ

Oxidative stress and inflammation arising from hyperglycaemia have been identified as important targets in mitigating hyperglycaemia-induced organ dysfunction in diabetics. Chrysophyllum albidum fruit is commonly consumed as fruit snacks because of its beneficial effects in diabetes management. This study aim to evaluate the protective mechanisms of Chrysophyllum albidum fruit extract (CAFE) in streptozotocin-induced rats involving attenuation of oxidative stress, nuclear factor-kappa B (NF-κB) and peroxisome proliferator-activated receptor-gamma (PPAR-γ). CAFE was investigated for in vitro antioxidant and alpha amylase inhibitory activity. Male Wistar rats were made diabetic by single intraperitoneal injection of streptozotocin (60 mg/kg). The rats were then treated with CAFE (100 and 200 mg/kg) and pioglitazone (10 mg/kg) for two weeks. Fasting blood sugar (FBS), blood pressure parameters, lipid profile, oxidative stress parameters, NF-κB and PPAR-γ were determined. The extract showed antioxidant and alpha amylase inhibitory activities. CAFE significantly reduced STZ-induced hyperglycaemia after 7 and 14 days of treatment. CAFE also reduced STZ-induced elevation of diastolic blood pressure and mean arterial pressure and as well reduced atherogenic index in diabetic rats. It significantly decreased lipid peroxidation but increased the enzymatic and non-enzymatic antioxidant markers in the plasma, liver, kidney and pancreas. The immunohistochemical analysis revealed that CAFE significantly decreased hepatic and renal tissues NF-κB while increasing PPAR-γ gene expressions. The results of this study collectively showed the protective effect of Chrysophyllum albidum fruit extract in streptozotocin-induced diabetic rats via modulation of oxidative stress and NF-κB/ PPAR-γ expressions.

Compensatory depression of arterial pressure and reversal of ECG abnormalities by Annona muricata and Curcuma longa in hypertensive Wistar rats

OBJECTIVES

Increasing hypertension incidence in Sub-Sahara Africa and the current cost of management of the metabolic disorder has necessitated research on medicinal plants employed in African Traditional Medicine for hypertension. Thus, this study evaluated antihypertensive effect of Annona muricata leaves or Curcuma longa rhizomes in experimentally-induced hypertensive male Wistar rats (n=70) which were unilaterally nephrectomized and daily loaded with 1% salt. Cardiovascular and haematological changes, as well as urinalysis were determined.

METHODS

Rats were uninephrectomized and NaCl (1%) included in drinking water for 42 days. Extract-treated hypertensive rats were compared to normotensive, untreated hypertensive and hypertensive rats treated with lisinopril (5 mg/70 kg) or hydrochlorothiazide (12.5 mg/70 kg). A. muricata extract or C. longa extract were administered at 100, 200 or 400 mg/kg. Blood pressure (systolic, diastolic and mean arterial) and electrocardiogram was measured on day 41. Twenty-four-hour urine samples were collected from day 42. Blood samples were collected on day 43 for haematology (PCV, red cell indices, WBC and its differentials, and platelets).

RESULTS AND CONCULSIONS

A. muricata or C. longa extracts caused a decline in elevated blood pressure of hypertensive rats. Heart rate and QT segment reduction coupled with prolonged QRS duration were reversed in extract-treated rats, with significant increases in hemogram parameters indicating increased blood viscosity. Also, leukocyturia, proteinuria and ketonuria with increased urine alkalinity, urobilinogen and specific gravity which are classical indicators of poor prognostic outcomes in hypertension were reversed in extract-treated rats. In conclusion, A. muricata and C. longa have cardioprotective effect with reversal of derangements in haemogram and urinalysis associated with hypertension.

Assessment of water quality of selected rivers in the Niger Delta region of Nigeria using biomarkers in Clarias gariepinus

Petroleum exploration has continued to impact negatively the Niger Delta region of Nigeria. Oil spills from petroleum exploration contaminate both the aquatic and non- aquatic environments and destroy the ecosystem which makes people in these regions to be prone to diseases such as cancer, cardiovascular diseases, neurodegenerative disease, infertility, and sterility and also poverty. Some oxidative stress markers of the liver and muscle of fish (Clarias gariepinus) from Apata, Araromi, and Mahin rivers (located in the Niger Delta region) were compared with those of fish samples from a clean fish farm (control) in order to assess the level of pollution of the rivers. A significant increase in malondialdehyde level and myeloperoxidase (MPO) activity as well as alterations in antioxidant status (glutathione peroxidase, superoxide dismutase, reduced glutathione, and glutathione S-transferase) was observed in the organs of fish samples from Apata, Araromi, and Mahin rivers compared with the control. A significant increase in the frequency of micronucleated polychromatic erythrocytes (MnPCEs) was also observed in the fish samples from these rivers in comparison with the control. Based on results of our research, we can conclude that these rivers are polluted mainly by oil spillage and other industrial activities; therefore, the consumption of aquatic organisms from these rivers and the use of water from the rivers for domestic activities might be unsafe.

Potential health benefits of zinc supplementation for the management of COVID-19 pandemic

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent for the Coronavirus Disease 2019 (COVID-19). The COVID-19 pandemic has created unimaginable and unprecedented global health crisis. Since the outbreak of COVID-19, millions of dollars have been spent, hospitalization overstretched with increasing morbidity and mortality. All these have resulted in unprecedented global economic catastrophe. Several drugs and vaccines are currently being evaluated, tested, and administered in the frantic efforts to stem the dire consequences of COVID-19 with varying degrees of successes. Zinc possesses potential health benefits against COVID-19 pandemic by improving immune response, minimizing infection and inflammation, preventing lung injury, inhibiting viral replication through the interference of the viral genome transcription, protein translation, attachment, and host infectivity. However, this review focuses on the various mechanisms of action of zinc and its supplementation as adjuvant for vaccines an effective therapeutic regimen in the management of the ravaging COVID-19 pandemic. PRACTICAL APPLICATIONS: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent for the Coronavirus Disease 2019 (COVID-19), has brought unprecedented untold hardship to both developing and developed countries. The global race for vaccine development against COVID-19 continues with success in sight with attendant increasing hospitalization, morbidity, and mortality. Available drugs with anti-inflammatory actions have become alternative to stem the tide of COVID-19 with attendant global financial crises. However, Zinc is known to modulate several physiological functions including intracellular signaling, enzyme function, gustation, and olfaction, as well as reproductive, skeletal, neuronal, and cardiovascular systems. Hence, achieving a significant therapeutic approach against COVID-19 could imply the use of zinc as a supplement together with available drugs and vaccines waiting for emergency authorization to win the battle of COVID-19. Together, it becomes innovative and creative to supplement zinc with currently available drugs and vaccines.

Ramipril blunts glycerol-induced acute renal failure in rats through its antiapoptosis, anti-inflammatory, antioxidant, and renin-inhibiting properties

OBJECTIVES

Acute kidney injury (AKI) is a malady with a sudden onset resulting in buildup of waste matters in the body, but a specific cure hasn't been found as a lasting solution to AKI. In this study, ramipril was evaluated for its potential therapy in glycerol-induced AKI in rats.

METHODS

Twenty animals were divided into four groups of five animals each. Group I was the control while group II was given glycerol on day 8 only, groups III and IV were administered with pioglitazone (reference drug) and ramipril for seven days respectively and on day 8 received glycerol. On the ninth day, blood and tissue samples were taken to assay for serum indicators of oxidative damage, enzymatic and nonenzymatic antioxidants, and creatinine and blood urea nitrogen. Animals were sacrificed thereafter; kidney was harvested for histological and immunohistochemical analysis. Expressions of caspase 3, renin receptor, NK-KB, and KIM-1 were carried out.

RESULTS

Ramipril significantly inhibited indicators of oxidative damage while also significantly increasing levels of enzymatic and nonenzymatic antioxidant markers. These drugs also significantly lowered the levels of creatinine and blood urea nitrogen. Histology also indicated that while there were massive infiltration of leucocytes and congestion of the kidney in toxicant group, the ramipril-treated group showed a milder condition. In immunohistochemistry, the two drugs significantly inhibited the expressions of the four proteins, which were highly expressed in the toxicant group.

CONCLUSIONS

The study showed that ramipril and pioglitazone have nephroprotective effect and thus have the ability to blunt AKI through their anti-inflammatory, antiapoptosis, antirenin, and antioxidant properties.

Luteolin supplementation ameliorates cobalt-induced oxidative stress and inflammation by suppressing NF-кB/Kim-1 signaling in the heart and kidney of rats

Cobalt-induced cardiomyopathy and renal toxicity have been reported in workers in processing plants, hard metal industries, diamond polishing and manufacture of ceramics. This study was designed to investigate the influence of Luteolin supplementation on cobalt-induced cardiac and renal toxicity in rats. Exposure of rats to cobalt chloride (CoCl₂) alone caused significant (p < 0.05) increases in cardiac and renal H₂O₂, malondialdehyde (MDA) and nitric oxide (NO), along with increased serum myeloperoxidase (MPO) activity. In addition, there were significant (p < 0.05) reductions in cardiac and renal glutathione peroxidase (GPx), glutathione S-transferase (GST) and reduced glutathione (GSH). CoCl₂ induced higher immuno-staining of nuclear factor kappa beta (NF-κB) in the heart and kidneys, and the kidney injury molecule (Kim-1) in the kidneys. Treatment with Luteolin or Gallic acid produced significant reversal of the oxidative stress parameters with reductions in NF-κB and Kim-1 expressions, leading to suppression of histopathological lesions observed in the tissues.

Novel antihypertensive action of rutin is mediated via inhibition of angiotensin converting enzyme/mineralocorticoid receptor/angiotensin 2 type 1 receptor (ATR1) signaling pathways in uninephrectomized hypertensive rats

Hypertension is the most common cardiovascular disease that affects approximately 26% of adult population, worldwide. Rutin is one of the important flavonoids that is consumed in the daily diet, and found in many food items, vegetables, and beverages. Uninephrectomy (UNX) of the left kidney was performed, followed by induction of hypertension. The rats were randomly divided into four groups of 10 rats: group 1-Sham-operated rats; group 2-UNX rats, group 3-UNX-L-NAME (40 mg/kg) plus rutin (100 mg/kg bwt), and groups 4-UNX-L-NAME plus lisinopril (10 mg/kg bwt), orally for 3 weeks. Results revealed significant heightening of arterial pressure and oxidative stress indices, while hypertensive rats treated with rutin had lower expressions of angiotensin converting enzyme (ACE) and mineralocorticoid receptor in uninephrectomized rats. Together, rutin as a novel antihypertensive flavonoid could provide an unimaginable benefits for the management of hypertension through inhibition of angiotensin converting enzyme and mineralocorticoid receptor. PRACTICAL APPLICATIONS: Hypertension has been reported to be the most common cardiovascular disease, affecting approximately 26% of the adult population worldwide with predicted prevalence to increase by 60% by 2025. Recent advances in phytomedicine have shown flavonoids to be very helpful in the treatment of many diseases. Flavonoids have been used in the treatment and management of cardiovascular diseases, obesity and hypertension. The study revealed that rutin, a known flavonoid inhibited angiotensin converting enzyme (ACE), angiotensin 2 type 1 receptor (ATR1), and mineralocorticoid receptor (MCR), comparable to the classic ACE inhibitor, Lisinopril, indicating the novel antihypertensive property of rutin. Therefore, flavonoids such as rutin found in fruits and vegetables could, therefore, serve as an antihypertensive drug regimen. Combining all, functional foods rich in flavonoids could be used as potential therapeutic candidates for managing uninephrectomized hypertensive patients.

Luteolin Attenuates Glycerol-Induced Acute Renal Failure and Cardiac Complications Through Modulation of Kim-1/NF-κB/Nrf2 Signaling Pathways

Acute renal failure (ARF) has been documented as a life-threatening disease with high morbidity and mortality. We investigated the protective effect of Luteolin against ARF. In this study, forty-male Wistar albino rats were randomly divided into four groups (n = 10). Group A received normal saline. Group B received glycerol (10 ml/kg BW, 50% v/v in sterile saline, i.m.). Groups C and D were pretreated with Luteolin 100 and 200 mg/kg for 7 days, and thereafter administered Glycerol (10 ml/kg BW, 50% v/v in sterile saline, i.m.). Administration of glycerol significantly increased systolic blood pressure, diastolic blood pressure and mean arterial pressure. Renal protein carbonyl and xanthine oxidase increased significantly while significant reduction in the activity of renal glutathione peroxidase, glutathione S-transferase and glutathione reductase was observed in the glycerol intoxicated rats. Furthermore, administration of glycerol led to significant increases in serum creatinine and blood urea nitrogen together with reduction in nitric oxide (NO) bioavailability. Immunohistochemistry revealed that glycerol intoxication enhanced expressions of kidney injury molecule 1, nuclear factor kappa beta and cardiac troponin (CTnI). However, Luteolin pretreatment normalized blood pressure, reduced markers of oxidative stress, renal damage, and improved NO bioavailability. Luteolin also downregulated the expressions of kidney injury molecule 1, nuclear factor kappa beta and cardiac troponin. Together, Luteolin might open a novel therapeutic window for the treatment of acute renal failure and cardiac complication.

Methanol leaf extract of Momordica charantia protects alloxan-induced hepatopathy through modulation of caspase-9 and interleukin-1β signaling pathways in rats

Background and Aim:

Momordica charantia is a highly valued plant, widely distributed in the tropical and subtropical regions. The plant is reported to have a wide range of medicinal uses. This study was designed to explore the ameliorative potential of M. charantia methanol leaf extract in alloxan-induced diabetic animal model with a particular focus on the liver.

Materials and Methods:

Hepatoprotective effect of methanol leaf extract of M. charantia was assessed in alloxan-induced toxicity in 50 rats divided into five groups (A-E) (n=10). Group A normal control, Group B was toxicant group, and Group C animals received glibenclamide treatment while Groups D and E received extracts at 200 and 400 mg/kg doses, respectively. The experiment lasted for 28 days. Histopathological changes, blood glucose level, and serum enzymes such as aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase, oxidative status and caspase-9, and interleukin-1β (IL-1β) were evaluated.

Results:

Extract-treatment caused a decreased blood glucose level, markers of oxidative stress such as malondialdehyde and hydrogen peroxide (H₂O₂). Treatment of rats with leaf extract of M. charantia resulted in increased levels and activities of protein thiols, non-protein thiols, glutathione (GSH), glutathione peroxidase, glutathione S-transferase, and superoxide dismutase indicating its antioxidant potential. The liver section revealed mild distortion of the hepatic architecture compared to the toxicant group, while decreased expressions of caspase-9 and IL-1β in extract-treated groups was observed.

Conclusion:

The plant extract exhibited antioxidant, anti-apoptotic, and anti-inflammatory effects, thus showing its hepatoprotective property.

Effects of caffeine and caffeic acid on selected biochemical parameters in L-NAME-induced hypertensive rats

Biologically active compounds such as caffeine and caffeic acid can be obtained in plants especially cocoa and coffee. Hence, the combinatory effect of caffeine and caffeic acid as well as their individual effect were assessed on the activities of arginase, angiotensin-1-converting enzyme (ACE) as well as nitric oxide (NOx), and malondialdehyde (MDA) level in the Nω-Nitro-L-arginine-methylester (L-NAME)-induced hypertensive rats. The individual and combinatory effect of caffeine and caffeic acid were investigated in L-NAME-induced rats. Animals were grouped into eleven containing six animals each. Hemodynamic parameter was determined by tail-cuff plethysmography. Furthermore, the result showed a notable rise in ACE and arginase activities of L-NAME-induced group compared with the control group. However, pretreatment with test compounds lowered ACE, arginase activities, and MDA content with rise in NOx. This study supports that caffeine and caffeic acid combinations demonstrated antihypertensive properties by lowering the systolic blood pressure in L-NAME-induced rats. PRATICAL APPLICATIONS: This duo bioactive compounds; caffeine (alkaloid) and caffeic acid (phenolic acid) are lavishly distributed in coffee. Their cardiopotective and cardiomodulatory roles have been investigated due to their biological activities. As far as we are aware, this could be foremost in-depth study on the antihypertensive and cardioprotective effect of the combinations of caffeine and caffeic acid targeting the key enzymes system relevant to hypertension. Decreased ACE and arginase activities as well as high nitric oxide (NOx) and low MDA level may be associated with its antihypertensive effect. This present study suggests that the combinations of this phenolics and alkaloid compound might proffer a therapeutic strategy in the management of hypertension.

Antihypertensive power of Naringenin is mediated via attenuation of mineralocorticoid receptor (MCR)/ angiotensin converting enzyme (ACE)/ kidney injury molecule (Kim-1) signaling pathway

Hypertension is a condition with chronic elevation of blood pressure and a common preventable risk factor for cardiovascular disease with attendant global morbidity and mortality. The present study investigated the novel antihypertensive and neuroprotective effect of Naringenin on L-N^G-Nitro arginine methyl ester (L-NAME) induced hypertension together with possible molecular mechanism of action. Rats were divided into four groups. Rats in Group A were normotensive. The hypertensive group (Group B) received 40 mg/kg) of L-NAME alone while Groups C and D were concurrently administered Naringenin (50 mg/kg) or Lisinopril (10 mg/Kg) together with L-NAME orally for 3 weeks. Blood pressure parameters, markers of oxidative stress and renal damage were measured. The immunohistochemistry of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme were also determined. Results indicated significant increases in malondialdehyde, advanced oxidation protein products, protein carbonyl contents and decrease in serum nitric oxide bioavailability in hypertensive rats. Furthermore, there were significant increases in serum myeloperoxidase, urinary creatinine, albumin and blood urea nitrogen in hypertensive rats in comparison to hypertensive rats treated with either Naringenin or Lisinopril. Immunohistochemistry reveal significant expressions of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme in hypertensive rats. However, co-treatment with either Naringenin or Lisinopril mitigated both renal and neuronal oxidative stress, normalized blood pressure and lowered the expressions of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme. Collectively, Naringenin offered a novel antihypertensive and neuroprotective effect through down regulation of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme.

Anti-lipidemic Effect of Fractions of Peristrophe bivalvis Leaf in NG-nitro-L-arginine Methyl Ester (L-NAME) Treated Rats

PURPOSE

The reduction in nitric oxide (NO) bioavailability accelerates atherosclerosis development, augments lipolysis, elevates blood pressure and upregulate leukocyte level. This study was designed to examine the biochemical constituents of fractions of Peristrophe bivalvis (PB) leaf, their effect on blood pressure, serum lipid contents and complete blood count in NG-nitro-L-arginine methyl ester (L-NAME) hypertensive rats.

METHOD

Male Wistar rats were grouped into control and hypertensive groups. The hypertensive group was pretreated with 60 mg/kg b.w of L-NAME (L-NAME60) daily for two weeks. They were then randomly sub-grouped into: Hypertensive (H), Hypertensive+n-hexane fraction (HHF), Hypertensive+dichloromethane fraction (HDF), Hypertensive+ethyl acetate fraction (HEF) and Hypertensive+aqueous fraction (HAF) groups. These were orally gavaged with L-NAME60 and L-NAME60+200 mg/kg b.w of fractions of PB respectively, daily for two weeks.

RESULT

The biochemical components analysis of the fractions of PB identified numerous polar and non polar compounds like alkaloids, organic acids and esters. The results showed a significant increase in NO level in HHF and HEF groups compared to H. Total cholesterol, triglyceride, low density lipoprotein cholesterol (LDL-C) and very LDL-C were significantly decreased in HAF group compared to H. High density lipoprotein cholesterol (HDL-C) increased significantly and atherogenic indices decreased significantly in HHF, HDF and HAF groups compared to H, while reduced glutathione level increased significantly in HHF group compared to H. White blood cells count effectively decreased in HEF group compared to H.

CONCLUSION

In brief, the fractions of PB leaf increased HDL-C and NO, and decrease atherogenic indices in L-NAME treated rats.

Ameliorative effects of Annona muricata Linn. (Annonaceae) against potassium dichromate-induced hypertension in vivo: involvement of Kim-1/p38 MAPK/Nrf2 signaling

Background Recently, the incidences of hypertension and environmental pollution have increased significantly. This study investigates the antihypertensive effect of Annona muricata extract against K2Cr2O7-induced hypertension. Methods Fifty rats were used for this study, which were divided into five groups of 10 rats each. Rats in Group A received normal saline, and those in Groups B, C, D, and E were treated with A. muricata extract alone at 250 mg/kg, K2Cr2O7 at 30 mg/kg, pretreated with the extract at 250 mg/kg, and pretreated with gallic acid at 60 mg/kg for 14 days, respectively, and thereafter administered with a single intraperitoneal injection of K2Cr2O7 at 30 mg/kg. Results Administration of K2Cr2O7 significantly increased systolic, diastolic, and mean arterial pressure and caused prolonged QT and QTc intervals. Further, pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg significantly reduced high blood pressure to near-normal values. K2Cr2O7 intoxication led to significant increases in serum advanced oxidative protein products, myeloperoxidase, and xanthine oxidase, while serum nitric oxide (NO) also reduced significantly. Immunohistochemistry of the renal kidney injury molecule (Kim-1) and p38 MAPK showed increased expressions following the administration of K2Cr2O7 together with the downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). Pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg also increased the expressions of Nrf2 and downregulated Kim-1 and p38. Conclusion Together, we found that pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg normalized the blood pressure, reduced the markers of oxidative stress, and improved the antioxidant defense system and serum NO bioavailability.

Effect of cocoa powder on hypertension and antioxidant status in uninephrectomized hypertensive rats

BACKGROUND AND AIM

High salt diet and uninephrectomy are associated with high blood pressure with attendant cardiovascular disease conditions such as hypertension, renal damage, myocardial infarction, and stroke. The aim of this study was to investigate the beneficial effects of consumption of cocoa and cocoa-containing products in the management of high blood pressure in uninephrectomized hypertensive rats.

MATERIALS AND METHODS

The effect of cocoa powder on blood pressure, markers of inflammation, oxidative stress, and histopathology were investigated in uninephrectomized animals fed with cocoa feed alone or in combination with a high salt diet. Male rats were randomly divided into five groups: Group A was the control group and fed with normal feed alone, Group B was fed with cocoa feed alone, Group C was fed with high salt diet (8% salt), GroupD was fed with cocoa-feed compounded with 8% salt for 4weeks after uninephrectomy, and GroupE was uninephrectomized rats on a normal diet. The left kidneys of animals in GroupsC, D, and E were removed by surgery. After 4weeks of treatment, the systolic, diastolic, and mean arterial blood pressure was measured. The serum markers of renal damage and oxidative stress were determined. Histological examination was also performed on renal and cardiac tissues.

RESULTS

Results showed significant increases in biomarkers of oxidative stress, inflammation, and renal damage with a concomitant decrease in antioxidant status in hypertensive uninephrectomized rats. Cocoa feed, however, significantly improved blood pressure and nitric oxide bioavailability, antioxidant status and reduced markers of inflammation and oxidative stress.

CONCLUSION

These findings show that cocoa powder could be used to maintain blood pressure levels in hypertensive rats through its antioxidant capacity.

Cobalt chloride toxicity elicited hypertension and cardiac complication via induction of oxidative stress and upregulation of COX-2/Bax signaling pathway

Cobalt is a ferromagnetic metal with extensive industrial and biological applications. To assess the toxic effects of, and mechanisms involved in cobalt chloride (CoCl₂)-induced cardio-renal dysfunctions. Male Wistar rats were exposed orally, daily through drinking water to 0 ppm (control), 150 ppm, 300 ppm, and 600 ppm of CoCl₂, respectively. Following exposure, results revealed significant ( p < 0.05) rise in markers of oxidative stress, but decreased activities of catalase, glutathione peroxidase, glutathione-S-transferase, and reduced glutathione content in cardiac and renal tissues. There were significant increases in systolic, diastolic, and mean arterial blood pressure at the 300- and 600-ppm level of CoCl₂-exposed rats relative to the control. Prolongation of QT and QTc intervals was observed in CoCl₂ alone treated rats. Also, there were significant increases in the heart rates, and reduction in P wave, and PR duration of rats administered CoCl₂. Histopathology of the kidney revealed peritubular and periglomerular inflammation, focal glomerular necrosis following CoCl₂ exposure. Further, cyclooxygenase-2 and B-cell associated protein X expressions were upregulated in the cardiac and renal tissues of CoCl₂-exposed rats relative to the control. Combining all, results from this study implicated oxidative stress, inflammation, and apoptosis as pathologic mechanisms in CoCl₂-induced hypertension and cardiovascular complications of rats.

Ameliorative effect of Rutin on sodium fluoride-induced hypertension through modulation of Kim-1/NF-κB/Nrf2 signaling pathway in rats

Sodium fluoride is one of the neglected environmental contaminants. Inorganic fluorides in the environment are found in the air, water, and land. In the study, forty-male Wistar albino rats were randomly divided into four groups with 10 rats in a group. Group A was the control group which was given normal saline, Group B was exposed to 300 ppm of NaF in drinking water, while Groups C and D received NaF along Rutin (100 mg/kg and 200 mg/kg) orally daily for a week. Administration of NaF alone led to significant increases in blood pressure, and deceased serum nitric oxide. Immunohistochemistry revealed higher expressions of kidney injury molecule I (Kim-1), nuclear factor kappa beta (NF-κB), and down regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) in rats administered NaF. Rutin co-treatment with NaF normalized blood pressure, lowered Kim-1 and NF-κB expressions, and improved nitric oxide bioavailability.

Cardio-protective and antioxidant properties of caffeic acid and chlorogenic acid: Mechanistic role of angiotensin converting enzyme, cholinesterase and arginase activities in cyclosporine induced hypertensive rats

Caffeic acid (CAA) and chlorogenic acid (CHA) are important members of hydroxycinnamic acid with natural antioxidant and cardio-protective properties. The present study aimed to determine the effect of CAA and CHA on systolic blood pressure, heart rates (HR) as well as on the activity of the angiotensin-1-converting enzyme (ACE), acetylcholinesterase (AChE), butrylcholinesterase (BChE) and arginase in cyclosporine-induced hypertensive rats. Experimental rats were distributed into 7 groups (n = 6): normotensive control rats; hypertensive rats (induced rats) as well as hypertensive- treated groups with captopril (10 mg/kg/day), CAA (10 and 15 mg/kg/day) and CHA (10 and 15 mg/kg/day), respectively. The experiment lasted for 7 days and the systolic blood pressure (SBP) and heart rates were recorded using tail-cuff method. Oral administration of captopril, caffeic acid and chlorogenic acid normalized hypertensive effect caused by cyclosporine administration. CAA and CHA significantly (P < 0.05) reduced SBP and HR, activity of ACE, AChE, BChE and arginase in the treated hypertensive rats compared with cyclosporine induced-hypertensive rats. Likewise, CAA and CHA improved nitric oxide (NO) bioavailability, increased catalase activity and reduced glutathione content while malondialdehyde (MDA) level was reduced compared with cyclosporine hypertensive rats. Findings from this study shows that CAA and CHA exhibited blood pressure lowering properties and reduced activities of key enzymes linked to the pathogenesis of hypertension in cyclosporine-induced rats. These might be some of the possible mechanisms of action by which their cardio-protective properties are exhibited.

Luteolin-mediated Kim-1/NF-kB/Nrf2 signaling pathways protects sodium fluoride-induced hypertension and cardiovascular complications

The use of sodium fluoride (NaF) as a major ingredient for tooth paste, mouth wash, and mouth rinse has become inevitable in our day-to-day life. However, flavonoids such as Luteolin might be of great value in the prevention of toxicity associated with accidental or inevitable ingestion of NaF. In the study, 40 male Wistar albino rats were randomly divided into four groups with 10 rats in a group. Group A was the control group and received normal saline, Group B was exposed to NaF at 300 ppm (300 mg/L) in drinking water daily for a week, Groups C and D were exposed to 300 ppm (300 mg/L) of NaF and coadministered with Luteolin orally daily at a dosage of 100 mg/kg and 200 mg/kg for the same time point. Our results indicated that NaF caused significant increases in systolic blood pressure, diastolic blood pressure, mean arterial pressure, malondialdehyde, protein carbonyl, myeloperoxidase, advanced oxidative protein products, together with significant reductions in glutathione peroxidase, superoxide dismutase, catalase, glutathione reductase, reduced glutathione, and nitric oxide (NO) bioavailability. The electrocardiogram results showed that NaF alone caused significant prolongation of QT and QTc intervals. Immunohistochemistry revealed that NaF caused increase expressions of Kidney injury marker 1 (Kim-1), nuclear factor kappa bet (NF-κB), nuclear factor erythroid 2-related factors 2 (Nrf2), and cardiac troponin I (CTnI). Together, Luteolin coadministration with NaF improved NO bioavailability, reduced high blood pressure, markers of oxidative stress, reversed prolongation of QT and QTc intervals, and lowered the expressions of Kim-1, NF-κB, and CTnI. © 2018 BioFactors, 44(6):518-531, 2018.

Nephroprotective properties of the methanol stem extract of Abrus precatorius on gentamicin-induced renal damage in rats

Background The use of plants for the treatment and prevention of diseases in man and his animals has led to a renewed scientific interest in the use of medicinal plants for therapeutic purposes. The nephroprotective properties of methanol stem bark extract of Abrus precatorius against gentamicin-induced renal damage in rats was evaluated in this study. Methods Thirty male Wistar rats were divided into five equal groups. Group A was the negative control group while B was the positive control group which received gentamicin 100 mg/kg intra-peritoneally for 6 days. Group C were pretreated with 100 mg/kg extract for the 3 days and then concurrently with gentamicin 100 mg/kg for 3 days and group D were pretreated with 200 mg/kg extract for 3 days and then concurrently with gentamicin 100 mg/kg for 3 days. Group E received gentamicin intraperitoneally for 6 days followed by administration of 200 mg/kg of the extract for 3 days. Blood samples, kidneys and kidney homogenates were collected for haematological, biochemical, histopathological and immunohistochemical analysis. Results The results showed that no significant haematological changes were noted. The groups treated with extract exhibited significant increase in body weight gain. While group B significantly exhibited focal areas of inflammation, fatty degeneration, congestion of vessels, tubular necrosis and glomerular atrophy, the lesions were mild with the treated groups. Treated groups exhibited a dose dependent significant decrease in serum creatinine, urea, XO, NO and Myeloperoxidase, AOPP, Protein carbonyl, H2O2 generated and MDA levels when compared with group B. There were significant dose dependent improvements in SOD, GST, GSH, Protein thiol, and non-protein thiol levels in the treated groups when compared with group B. In immunohistochemistry, Group B exhibited over expression of CRP and NF-κB levels, and marked reduction in expression of Bcl-2 while the reverse was seen in the groups treated with methanol extracts of Abrus precatorius. Conclusion The methanol extract of Abrus precatorius plays a vital role against gentamicin induced renal damage by reducing levels of renal markers of oxidative stress, inflammation and apoptosis, enhancing enzymatic and non enzymatic renal antioxidant system, alongside an increase in Bcl-2 and a decrease in NF-κB and CRP expressions.

Lassa fever outbreak in adolescents in North Central Nigeria: report of cases

BACKGROUND

Lassa fever (LF) is a viral haemorrhagic fever endemic to West Africa. The clinical presentation and course is variable, making diagnosis difficult.

AIM

To report the outbreak and identify the common clinical presentations of LF in paediatric patients in Jos, Plateau State, North Central, Nigeria.

METHODS

This was a retrospective review of patients managed for LF during the June-August 2017 outbreak. LF was suspected in cases with: fever of less than 3 weeks' duration that had not responded to antimalarials or antibiotics, myalgia, abdominal pain, prostration and history of contact with any person diagnosed with LF. LF was confirmed by a positive reverse transcriptase polymerase chain reaction test (RT-PCR).

RESULTS

Ten adolescents were studied. The common presenting complaints were fever (100%), prostration (90%) and headache (70%) while the commonest clinical signs were pyrexia (temperature >38.0^oC; 90%), prostration (80%) and abdominal tenderness (80%). Leukocytes were present in urine in 60%. Eight individuals recovered fully, one adolescent died and one developed intestinal perforation necessitating laparotomy.

CONCLUSION

In settings such as North Central Nigeria, LF should be suspected in any patient with fever that is unresponsive to antimalarials and antibiotics, especially in the presence of prostration, tachypnoea, tachycardia or abdominal tenderness. Early diagnosis and treatment is needed to reduce mortality from the disease and protect against transmission to health personnel.