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.

Antioxidant and Chemopreventive Effects of Azadirachta indica on Lead Acetate-induced Hepatotoxicity in Male Wistar Rats.

Toxic metals such as lead (Pb) cause severe liver damage in humans and animals, with oxidative stress prominently implicated in the pathogenesis of lead acetate­induced liver injury. Azadirachta indica is hepatoprotective due to its antioxidative effect. This study investigated the antioxidative role of A. indica (AI) and its chemopreventive effect on lead acetate (LA)-induced hepatocellular dysfunction with seventy adult male rats classified into group A- Control (distilled water), group B 0.1% LA only, group C and D- 0.1% LA + 100 mg/kg and 0.1% LA + 200 mg/kg AI respectively, group E- 0.2% LA, group F and G- 0.2% LA + 100 mg/kg and 0.2% LA + 200 mg/kg AI. Oxidative stress markers (MDA and H2O2), antioxidant parameters (GSH, SOD, CAT, GPx, GST), inflammatory markers (MPO and NO), alanine aminotransferase (ALT) and histopathological studies of the liver were evaluated. The results showed that LA administration caused a decrease in GSH, GPx, and GST while AI co-administration increased the activities of the antioxidants. Moreover, LA administration increased MPO, NO, MDA, and H2O2 levels whereas AI significantly reduced (P<0.05) these parameters. Histopathological examination revealed necrosis and mild infiltration by inflammatory cells in LA administered rats, whereas these lesions were absent in AI administered rats. In conclusion, A. indica demonstrates a protective role in lead acetate-induced hepatotoxicity, mainly via oxidative stress inhibition.

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.

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.

Bioremediation treatment improves water quality for Nile tilapia (Oreochromis niloticus) under crude oil pollution.

Despite favorable publicity of bioremediation as an affordable technology for cleanup of crude oil, public concerns on ecological safety in the presence of residual oil remain a global challenge. In this study, effects of crude oil exposure at sublethal concentration (0.25% v/v) and bioremediation treatment were investigated on histology and biochemical parameters of organs (gills, liver, kidney, and brain) of juvenile Nile tilapia (Oreochromis niloticus). Ten percent (10%) of mixed bacterial culture was used for bioaugmentation treatment. Ninety juvenile fish were used for study, and experiments were carried out in triplicates for three different groups. Malondialdehyde (MDA), an index of lipid peroxidation, was assayed as biomarker for oxidative stress. Activities of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)), level of non-enzymatic antioxidant (reduced glutathione (GSH)), and activity of brain acetylcholinesterase (AChE) were assayed in selected fish organs as markers for environmental stressor. Histological examination of fish organs was done for all groups. Results of treated groups were compared with those of the control. Levels of MDA significantly increased with significant inhibition of antioxidant enzyme activities in the polluted group. Activities of SOD, CAT, and AChE and levels of GSH in fish organs in the bioaugmentation group were similar to results obtained in the control. Remarkably, the bioaugmentation group showed minimal or no lesions which suggested the efficacy of bioremediation technique in alleviating crude oil toxicity and preserving normal physiology of fish. This study provides deeper insights into the ecosafety of bioremediation treatment and can be extrapolated to other species of fish.

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-NG-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.

Clofibrate, a PPAR-α agonist, abrogates sodium fluoride-induced neuroinflammation, oxidative stress, and motor incoordination via modulation of GFAP/Iba-1/anti-calbindin signaling pathways.

Fluoride is an environmental contaminant that is ubiquitously present in air, water, and soil. It is commonly added in minute quantity to drinking water, toothpaste, and mouth rinses to prevent tooth decay. Epidemiological findings have demonstrated that exposure to fluoride induced neurodevelopmental toxicity, developmental neurotoxicity, and motor disorders. The neuroprotective effect of clofibrate, a peroxisome proliferator-activated receptor alpha agonist, was investigated in the present study. Forty male Wistar rats were used for this study and randomly grouped into 10 rats per group as control, sodium fluoride (NaF) alone (300 ppm), NaF plus clofibrate (250 mg/kg), and NaF plus lisinopril (10 mg/kg), respectively, for 7 days. NaF was administered in drinking water while clofibrate and lisinopril were administered by oral gavage. Markers of neuronal inflammation and oxidative stress, acetylcholinesterase activity, and neurobehavioral (hanging wire and open field) tests were performed. Immunohistochemistry was performed on brain tissues, and they were probed with glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, and cerebellar Ca2+ -binding protein calbindin-D28k. The results showed that NaF significantly increased of oxidative stress and neuroinflammation and inhibited AChE activity. Immunostaining showed reactive astrocytes, microgliosis, loss of dendritic spines, and arborization in Purkinje cells in rats administered only NaF. Neurobehavioral results showed that cotreatment of NaF with clofibrate improved muscular strength and locomotion, reduced anxiety, and significantly reduced astrocytic count. Overall, cotreatment of NaF with either clofibrate or lisinopril showed neuroprotective effects by mitigating neuronal inflammation and oxidative and motor incoordination. Hence, clofibrate could be seen as a novel drug candidate against neurodegeneration and motor disorders.

Antihypertensive Effect of Polyphenol-Rich Fraction of Azadirachta indica on Nω-Nitro-L-Arginine Methyl Ester-Induced Hypertension and Cardiorenal Dysfunction.

Azadirachta indica (AI) is a medicinal plant with reported antioxidant and cardio-protective properties. The use of plant-based polyphenols has become greatly increased in the last one decade. The present study investigated the protective effect of the polyphenol-rich fraction (PRF) of the methanol-extract of Azadirachta indica against Nω-Nitro-L-Arginine Methyl Ester (L-NAME) induced hypertension and cardiorenal dysfunction in rats. Fifty (50) Wistar albino rats were grouped into five groups. Group A, the control, was administered potable water. Groups B-E received orally, 40 mg/kg of L-NAME only, 40 mg/kg of L-NAME and 100 mg/kg of AI extract, 40 mg/kg of L-NAME and 200 mg/kg of AI extract, and 40 mg/kg of L-NAME and 25 mg/kg of captopril, respectively for 21 days. The results of the present study revealed that L-NAME administration led to a significant increase in systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure. Markers of oxidative stress (malondialdehyde,protein carbonyl) increased significantly while there was reduction in reduced glutathione level, activities of superoxide dismutase, glutathione peroxidase and glutathione-S-transferase as well nitric oxide bioavailability. Immunohistochemistry revealed higher expressions of nuclear factor kappa beta (NF-kB) and kidney injury molecule 1(Kim-1) and lower expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) in hypertensive rats. Our results indicated that with PRF of AI restored high blood pressure, reduced markers of oxidative stress, normalized serum NO bioavailability and increased the expressions of Nrf2. Hence, PRF of Azadirachta indica could be used for the treatment of hypertension.

The ethanol leaf extract of Andrographis paniculata blunts acute renal failure in cisplatin-induced injury in rats through inhibition of Kim-1 and upregulation of Nrf2 pathway.

Background Cisplatin (CP) is a novel drug of choice in the treatment of cancer but its major limitation is nephrotoxicity, which is dose limiting. Andrographis paniculata (AP) is a common Indian dietary component. It is well known for its medicinal properties. This present study investigated the nephroprotective effect of ethanol leaf extract of Andrographis paniculata (EEAP) on CP-induced nephrotoxicity. Methods CP was used to induce nephrotoxicity in male Wistar rats to study the effect of EEAP on renal damages using hematological parameters, biochemical parameters, histology, and immunohistochemistry studies. Results The effects of EEAP were determined by CP-induced changes in different kidney tissue on antioxidant enzymes, markers of oxidative stress, serum creatinine, and urine parameters. Administration of EEAP (200 mL/kg and 400 mg/kg orally), prior to and following a single dose CP treatment (10 mg/kg i.p), significantly mitigated the CP-induced decrease in antioxidant enzymes, and increase in markers of oxidative stress, serum creatinine, and urinary protein. On histopathological examination of the kidney tissue, there was severe glomerular degeneration and infiltration of inflammatory cells in CP only treated rats, mild glomerular degeneration, and infiltration of inflammatory cells in EEAP pre-treated rats. Furthermore, EEAP activated Nrf2 and mitigated Kim-1 pathways in CP-induced nephrotoxicity. Conclusions The results showed the protective effect of EEAP against CP-induced nephrotoxicity.

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.

Quercetin attenuates hypertension induced by sodium fluoride via reduction in oxidative stress and modulation of HSP 70/ERK/PPARγ signaling pathways.

Hypertension is one of the silent killers in the world with high mortality and morbidity. The exposure of humans and animals to fluoride and/or fluoride containing compounds is almost inevitable. This study investigated the modulatory effects of quercetin on sodium fluoride (NaF)-induced hypertension and cardiovascular complications. Forty male rats were randomly separated into four groups (n =10). Group A animals served as the control, rats in Group B were exposed to 300 ppm of NaF, Groups C and D animals were exposed to 300 ppm of NaF along with quercetin orally at 50 mg/kg and 100 mg/kg orally by gavage, while NaF was administered in drinking water, respectively, for a week. Administration of NaF caused severe hypertension as indicated with significant increases in the systolic, diastolic, and mean arterial blood pressure, together with prolonged ventricular depolarization (QRS) and the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle (QT) intervals when compared with controls. NaF significantly decreased the activities of antioxidant enzymes, caused increase in markers of oxidative stress and renal damage when compared with controls. Immunohistochemical staining revealed lower expressions of Hsp70, ERK, and PPARγ in the heart, kidney, and aorta of rats-administered NaF relative to the controls. Together, quercetin co-treatment with NaF restored blood pressure, normalized QRS interval, and improved antioxidant defense system. © 2018 BioFactors, 44(5):465-479, 2018.

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.

Kolaviron attenuated arsenic acid induced-cardiorenal dysfunction via regulation of ROS, C-reactive proteins (CRP), cardiac troponin I (CTnI) and BCL2.

Arsenic acid is one of the abundant environmental pollutants present in soil, water and the air. Undoubtedly, it has found its way to the food chain in which humans and animals are the final targets thereby causing arrays of disease conditions including cardiovascular and renal dysfunction. Hence, the use of phytochemicals present in medicinal plants has gained global acceptance as chemotherapeutic agents that can prevent, ameliorate, reverse or treat diseases. From our study, arsenic acid intoxication led to significant increase in heart rate (HR), QRS, together with prolonged QT and QTc interval. However, Kolaviron (KV) at the dosage of 100 and 200 mg/kg body weight reversed the aforementioned electrocardiographic (ECG) changes. KV pre-treatment also ameliorated cardiorenal dysfunction via significant reduction in cardiac and renal markers of oxidative stress such as malondialdehyde, hydrogen peroxide generation, myeloperoxidase activity and nitric oxide contents. Immunohistochemistry revealed expressions of renal C-reactive proteins (CRP) and expressions of anti-apoptotic protein BCL2 in KV treated rats. Furthermore, cardiac troponin I (CTnI) expressions were lower in KV treated rats. Taken together, KV mitigated arsenic-acid induced cardiovascular dysfunction via up-regulation of antioxidant defense system and down-regulation of inflammatory and apoptotic signaling pathways.

The Protective Effect of the Ethanol Leaf Extract of Andrographis Paniculata on Cisplatin-Induced Acute Kidney Injury in Rats Through nrf2/KIM-1 Signalling Pathway.

The ethanol leaf extract of Andrographis paniculata was used to ameliorate the renal toxicity induced by cisplatin in 28 rats divided into four groups of seven rats per group. Group A received normal saline for the duration of the experiment. Group B animals were treated with cisplatin (10 mg/kg i.p) on day 1 and 3 days after received normal saline for the next 7 days while groups C and D animals also received 10 mg/kg dose of cisplatin on day 1 but after 3 days were then respectively treated with 200 and 400 mg/kg doses of the extract of Andrographis paniculata for the remaining 7 days through oral administration. Serum chemistry was used for the determination of markers of oxidative stress, anti-oxidant enzymes, serum biomarkers etc. Histopathology and immunohistochemistry were also carried out. Results showed that all oxidative stress markers assayed were significantly increased in group B animals but reverse is the case for groups C and D. On the other hand, antioxidant enzymes assayed experienced significant increase for groups C and D while these parameters experienced significant decrease for group B animals. Histopathology showed severe infiltration of inflammatory cells into renal tissues of group B animals whereas for groups C and D animals, only moderate glomerular degeneration was noted. In immunohistochemistry, while there is higher expression of KIM-1 for group B, there was a lower expression in groups C and D. Again, there was lower expression of Nrf2 for group B but higher expressions in groups C and D animals.

Telferia Occidentalis and Vitamin C Attenuate Phenylhydrazine-Induced Haemolytic Anaemia and Associated Cardio-renal Dysfunctions via Inhibition of Oxidative Stress and Proapoptotic -Protein (Bax) Expressions.

BACKGROUND: The study investigated the modulatory roles of the aqueous leaf extract of Telferia occidentalis, a traditional haematinic, and vitamin C on cardiovascular dysfunction associated with subchronic Phenylhydrazine exposure. METHODS: Fifty adult male rats were randomly selected and divided into one of five groups of ten animals each: Control; 40 mgkg-1 Phenylhydrazine (PHZ); PHZ with 100 mgkg-1 T.occidentalis; PHZ with 200 mgkg-1 T.occidentalis; and PHZ with 100 mgkg-1 vitamin C. RESULTS: Oral exposure of rats to PHZ, without T. occidentalis or vitamin C treatment, resulted in a significant (p<0.05) decrease in the haematological parameters, but increased the blood pressure parameters of rats However, treatment with vitamin C and T. occidentalis leaf extract significantly (p<0.05) ameliorated the aforementioned PHZ-induced alterations of rats haemogram, and blood pressure. Biochemical analysis revealed significant (p<0.05) reduction in the activities of superoxide dismutase and catalase of untreated PHZ-exposed rats, but the levels of malondialdehyde, hydrogen peroxide and myeloperoxidase of the rats were significantly (p<0.05) increased compared with those of the extract treated rats. Immunohistochemical analysis revealed a greater expression of Bax-protein in the cardiac and renal tissues of the untreated PHZ exposed rats, compared with the extract and vitamin C treated groups. CONCLUSIONS: The mitigation of oxidative stress and inhibition of Bax-protein expression are probable mechanisms of action of T. occidentalis in the amelioration of haemolytic anaemia, and its use as adjunct medication in the management of some diseases is justifiable.

Ameliorative effect of gallic acid on doxorubicin-induced cardiac dysfunction in rats.

BACKGROUND: The use of doxorubicin (DOX) as an antineoplastic agent has been greatly limited because of the myriad of toxic sequelae associated with it. The aim of this study was to assess the protective effects of gallic acid (GA) on DOX-induced cardiac toxicity in rats. METHODS: Sixty male rats (Wistar strain) were used in this study. They were divided into six groups (A-F) each containing 10 animals. Group A was the control. Rats in Groups B, C, and D were treated with DOX at the dosage of 15 mg/kg body weight i.p. Prior to this treatment, rats in Groups C and D had been treated orally with GA for 7 days at the dosage of 60 and 120 mg/kg, respectively. Animals from Groups E and F received only 60 and 120 mg/kg GA, respectively, which were administered orally for 7 days. RESULTS: The exposure of rats to DOX led to a significant (p<0.05) decrease in the cardiac antioxidant defence system and elevation of creatine kinase myocardial band and lactate dehydrogenase. The electrocardiography results showed a significant decrease in heart rate, QRS, and QT-segment prolongation. GA alone improved the antioxidant defence system. CONCLUSIONS: The GA pretreatment significantly alleviated GA-associated ECG abnormalities, restored the antioxidant status and prevented cardiac damage.

Ameliorative effect of Azadirachta indica on sodium fluoride-induced hypertension through improvement of antioxidant defence system and upregulation of extracellular signal regulated kinase 1/2 signaling.

BACKGROUND: Toxicities due to fluoride exposure from natural and industrial sources occur commonly in man and animals with severe consequences ranging from mild cardiac derangements to sudden death. In this study, we investigated the protective effects of the methanol extract of Azadirachta indica (AI) against sodium fluoride (NaF)-induced hypertension and genotoxicity in rats. METHODS: Sixty rats were divided into six groups of ten rats each as follows: Group A, the control group received distilled water; Group B rats were administered NaF at 600 ppm in drinking water; Groups C and D rats were pre-treated with the methanol extract of AI and thereafter administered NaF at 600 ppm in drinking water for 7 consecutive days; Groups E and F rats were co-administered with AI and NaF. RESULTS: The administration of NaF caused significant (p<0.05) increases in the blood pressure, markers of oxidative stress, serum myeloperoxidase, xanthine oxidase values in NaF-alone treated rats, compared with the control. Significant (p<0.05) decreases were observed in cardiac and renal antioxidant defence system in rats administered NaF alone compared with the control group. NaF treatment also resulted in a reduction in the expressions of extracellular signal-regulated kinase (ERK) 1/2 in cardiac and renal tissues of NaF-treated rats. Moreover, NaF treatment elicited an increase in the frequency of micronucleated polychromatic erythrocytes when compared with the control group. CONCLUSIONS: This study shows the protective effect of AI on NaF-induced hypertension and genotoxicity through antioxidant and ERK 1/2 signaling in rats.

Polyphenol-Rich Fraction of Parquetina nigrescens Mitigates Dichlorvos-Induced Cardiorenal Dysfunction Through Reduction in Cardiac Nitrotyrosine and Renal p38 Expressions in Wistar Rats.

Parquetina nigrescens is commonly used to treat diseases in humans and animals in developing countries, including Nigeria. This study evaluates the effects of its polyphenol-rich fraction (prf) on dichlorvos-induced cardio- and renal toxicity. There were several factors assessed during this study, including cardiac and renal markers, serum myeloperoxidase and xanthine oxidase, and electrocardiograph (ECG) changes. The changes in electrocardiograph (ECG) were recorded. Immunohistochemistry of cardiac and renal p38 and nitrotyrosine was determined. Dichlorvos exposure caused a significant decrease in L-glutathione (reduced glutathione) and other antioxidant enzymes with increases in malondialdehyde, myeloperoxidase, advanced oxidation protein products, and protein carbonyl levels. It also brought about alterations in microanatomy of the heart and kidneys accompanied by increases in serum creatinine and urea levels. Exposure to dichlorvos induced prolonged QRS interval and shortened QT durations in rats. Immunohistochemistry revealed lower expressions of cardiac nitrotyrosine and renal p38 (mitogen-activated protein kinase; MAPK) in rats treated with prf of P. nigrescens. Combining all, prf of P. nigrescens demonstrated antioxidant as well as protective properties in the heart and kidneys of rats exposed to dichlorvos. It ameliorated dichlorvos-induced cardio- and nephrotoxicity giving credence to its use in ethnomedicine.

Protective Effect of Azadirachta indica and Vitamin E Against Arsenic Acid-Induced Genotoxicity and Apoptosis in Rats.

Sodium arsenite (NaAsO2) is one of the major environmental toxicants with severe toxicological consequences in some developing and developed countries. Rats in Group A received normal saline. Genotoxicity and apoptosis were induced by single intraperitoneal injection of 10 mg/kg sodium arsenite to rats in Groups B-F. Rats in Groups C and D had earlier been pretreated with Azadirachta indica (100 and 200 mg/kg) or E and F with vitamin E (50 and 100 mg/kg), respectively. Markers of oxidative stress, inflammation, hepatic damage, genotoxicity, and apoptosis were assessed. Pretreatment of rats with either Azadirachta indica or vitamin E led to a significant (p <.05) increase in the activities of glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH) in the liver compared to the group that received NaAsO2 alone. Markers of oxidative stress and inflammation, malondialdehyde (MDA), hydrogen peroxide (H2O2) generation, nitric oxide (NO), and myeloperoxidase (MPO), were significantly (p <.05) lowered in rats pretreated with Azadirachta indica or vitamin E. The frequency of micronucleated polychromatic erythrocytes (MNPCEs) and expression of caspase-3 were significantly (p <.05) reduced in rats pretreated with either Azadirachta indica or vitamin E compared to rats intoxicated with arsenite. Histopathology of the liver showed areas of infiltration of inflammatory cells with deaths of numerous hepatocytes in NaAsO2-intoxicated rats, and these were reversed by Azadirachta indica. Together, we report for the first time the genoprotective and antiapoptotic effect of Azadirachta indica by a significant reduction in the frequency of micronuclei-induced apoptosis and oxidative stress by arsenic intoxication.