Browsing by Author "Areola, Emmanuel Damilare"

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    Endoglin inhibition by sodium acetate and flutamide ameliorates cardiac defective G6PD-dependent antioxidant defense in gestational testosterone exposed rats
    (Elsevier, 2018-08-25) Olatunji, Lawrence Aderemi; Areola, Emmanuel Damilare; Badmus, Olufunto
    Gestational androgen excess has been implicated in the development of cardiac dysfunction with poor me chanistic delineation. The role of sodium acetate on cardiac uric acid (UA) production and glucose-6-phosphate dehydrogenase (G6PD)-dependent antioxidant defense in pregnancy is not known. The study therefore sought to test the hypothesis that rats exposed to elevated testosterone in late pregnancy would have increased cardiac UA production and defective G6PD-dependent antioxidant defense. We also hypothesized that sodium acetate (SAc) or androgen receptor blocker, flutamide (Flu) would ameliorate these effects through endoglin inhibition. Twenty-four pregnant Wistar rats were treated (sc) with olive oil, testosterone propionate (0.5 mg/kg) singly or in combination with SAc (200 mg/kg; po) or Flu (7.5 mg/kg; po) in the late gestation between gestational day 14 and 19. The results showed that in the late gestation, testosterone exposure led to increased plasma and cardiac endoglin. In the heart of rats exposed to gestational testosterone there were elevated lactate dehydrogenase, adenosine deaminase, xanthine oxidase, uric acid (UA), cardiac injury markers and decreased G6PD-dependent antioxidant defense. However, either SAc or Flu comparably ameliorated these testosterone-induced effects. The data from the present study revealed that testosterone exposure in the late gestation causes elevated cardiac Eng that is accompanied by increased UA production and defective G6PD-dependent anti-oxidant defenses. Besides, the findings also suggest that the inhibitory effect of SAc or Flu on endoglin attenuates UA production and enhances the G6PD-dependent anti-oxidant barrier, thereby implying that endoglin may be a potentially novel therapeutic intervention for cardiac dysfunction particularly in pregnancy
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    Enhanced hepatic glycogen synthesis and suppressed adenosine deaminase activity by lithium attenuates hepatic triglyceride accumulation in nicotine exposed ra
    (Elsevier, 2018-10-12) Dangana, Elizabeth; Michael, Olugbenga; Omolekulo, Tolulope; Areola, Emmanuel Damilare; Olatunji, Lawrence Aderemi
    Reduced liver glycogen synthesis might signify increased glucose flux towards fat synthesis and triggers hepatic triglyceride accumulation and dysmetabolism. Adenosine deaminase (ADA) reduces adenosine content which increases glycogenolysis. In the present study, we evaluate the effect of modulating glycogen synthesis and ADA by lithium chloride (LiCl) on nicotine-induced dysmetabolism. Twenty four male Wistar rats (n = 6/group) were allotted into four groups namely; vehicle-treated (po), nicotine-treated (1.0 mg/kg; po), LiCl-treated (5.0 mg/kg; po) and nicotine + LiCl-treated groups. The treatments lasted for 8 weeks. Nicotine exposure resulted in reduced body weight gain, liver weight, visceral adiposity, glycogen content and synthase. Along with increased insulin resistance (IR), fasting plasma glucose, lactate, plasma and hepatic ADA, XO, UA, and triglyceride (TG), total cholesterol (TC), free fatty acid, lipid peroxidation and liver injury markers. However, plasma and hepatic glucose-6-phosphate dehydrogenase-dependent antioxidant defenses were not affected by nicotine exposure. Concurrent treatment with LiCl normalizes all alterations with exception of hepatic TC. This result shows that enhancement of hepatic glycogen synthesis and suppression of ADA/XO/uric acid pathway by lithium can salvage the liver from nicotine-induced TG accumulation.
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    Sildenafil ameliorates leptin resistance and normalizes lipid handling in the hypothalamic and adipose tissues of testosterone-exposed pregnant rats
    (Elsevier, Cell Press, 2021-07-12) Areola, Emmanuel Damilare; Sabinari, Isaiah Woru; Usman, Taofeek Olumayowa; Abayomi, Faith Ifeoluwa; Onyezia, Onyeka; Onaolapo, Bisola; Adetokunbo, Phebe Oluwaseun; Adebanjo, Olympus Oyewole; Oladipupo, Funmilayo Rebecca; Olatunji, Lawrence Aderemi
    Leptin and hypothalamic-adipose lipid handling are relevant in determining the shift of metabolic activities. There are scanty findings connecting glucose dysregulation as a result of hyperandrogenism during gestation to hypothalamic-adipose axis and leptin resistance. Sildenafil has recently gained attention in the prevention of intra-uterine growth restriction. The present study aimed at demonstrating the effect of sildenafil on leptin resistance and hypothalamic-adipose lipid handling in testosterone-exposed pregnant rats. Three groups of pregnant Wistar rats (n ¼ 5/group) received olive oil (Ctr, S.C.) or testosterone propionate (Tes, 3.0 mg/kg; sc)or testosterone propionate (3.0 mg/kg; sc) and sildenafil (Tes þ PDE5, 50 mg/kg; po)from gestational day 14–19. Blood samples, hypothalamus and adipose tissue were excised for biochemical analysis on day 20. Adipose and body weights, plasma leptin and adiponectin, adipose and hypothalamic leptin and triglyceride, adipose uric acid, hypothalamic Nrf2, catalase and nitric oxide were reduced following gestational testosterone exposure. Also, fasting insulin, plasma triglyceride, uric acid, leptin-adiponectin ratio, hypothalamic free fatty acid, total cholesterol, uric acid, aspartate transaminase and cyclic guanine monophosphate were elevated by testosterone exposure to pregnant animals. Sildenafil ameliorated leptin resistance and normalized hypothalamic-adipose lipid handling. Therefore, sildenafil protects against testosterone-induced leptin resistance and adverse hypothalamic adipose lipid handling in pregnant rats.
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    Sildenafil augments fetal weight and placental adiponectin in gestational testosterone-induced glucose intolerant rats
    (Elsevier, 2021-06-14) Areola, Emmanuel Damilare; Adewuyi, Ifeoluwa Jesufemi; Usman, Taofeek Olumayowa; Tamunoibuomi, God’sgift; Arogundade, Lucy Kemi; Olaoye, Barakat; Matt-Ojo, Deborah Damilayo; Jeje, Abdulrazaq Olatunji; Oyabambi, Adewumi Oluwafemi; Afolayan, Enoch Abiodun; Olatunji, Lawrence Aderemi
    Testosterone induces intra-uterine growth restriction (IUGR) with maternal glucose dysregulation and oxidant release in various tissues. Adiponectin, which modulates the antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is expressed in the placenta and affects fetal growth. Sildenafil, a phosphodiesterase type 5 inhibitor (PDE5i), used mainly in erectile dysfunction has been widely studied as a plausible pharmacologic candidate in IUGR. Therefore, the present study sought to determine the effect of PDE5i on placental adipo nectin/Nrf2 pathway in gestational testosterone-induced impaired glucose tolerance and fetal growth. Fifteen pregnant Wistar rats were allotted into three groups (n = 5/group) receiving vehicles (Ctr; distilled water and olive oil), testosterone propionate (Tes; 3.0 mg/kg; sc) or combination of testosterone propionate (3.0 mg/kg; sc) and sildenafil (50.0 mg/kg; po) from gestational day 14–19. On gestational day 20, plasma and placenta homogenates were obtained for biochemical analysis as well as fetal biometry. Pregnant rats exposed to testosterone had 4-fold increase in circulating testosterone compared with control (20.9 ± 2.8 vs 5.1 ± 1.7 ng/mL; p < 0.05) whereas placenta testosterone levels were similar in testosterone- and vehicle-treated rats. Exposure to gestational testosterone caused reduction in fetal and placental weights, placental Nrf2 and adiponectin. Moreover, impaired glucose tolerance, elevated plasma triglyceride-glucose (TyG) index, placental triglyceride, total cholesterol, lactate, malondialdehyde, and alanine aminotransferase were observed in testosterone-exposed rats. Treatment with sildenafil improved glucose tolerance, plasma TyG index, fetal and placental weights and reversed placental adiponectin in testosterone-exposed pregnant rats without any effect on placental Nrf2. Therefore, in testosterone-exposed rats, sildenafil improves impaired glucose tolerance, poor fetal outcome which is accompanied by augmented placental adiponectin regardless of depressed Nrf2.
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    Sodium acetate ameliorated systemic and renal oxidative stress in high-fructose insulin-resistant pregnant Wistar rats
    (Springer, 2021-02-27) Oyabambi, Adewumi Oluwafemi; Michael, Olugbenga Samuel; Areola, Emmanuel Damilare; Saliu, Salam Babatunde; Olatunji, Lawrence Aderemi
    Pregnancy is an insulin-resistant condition, especially at near term predisposing maternal kidneys to hyperinsulinemia-induced oxidative stress. The impact of fructose on renal metabolic dysregulation and oxidative stress in pregnancy requires elucidation. Short-chain fatty acids (SCFAs) are known for protective roles in oxidative stress conditions. Therefore, the study aimed at investigating fructose-induced glucose dysregulation and renal oxidative stress in pregnant and non-pregnant rats and the possible preventive role of SCFA, acetate. Thirty female Wistar rats were grouped (n = 5/group). Three groups were made pregnant (P); the other three remained non-pregnant (NP). Both pregnant and non-pregnant rats received drinking water (control), 10% fructose (w/v) (NP+F or P+F), and 10% (w/v) fructose plus sodium acetate (200 mg/kg) (NP+F+A or P+F+A) for 3 weeks. Renal and plasma glutathione antioxidant index (GSH/GSSG), G6PDH, and adenosine were significantly lower in NP+F and P+ F groups compared with control while renal and plasma adenosine deaminase (ADA), xanthine oxidase (XO), uric acid (UA), lactate dehydrogenase (LDH), and malonaldehyde (MDA) were significantly elevated in NP+F and P+F groups compared with controls. HOMA-IR showed marked impairment in both NP+F and P+F groups. The P+F group revealed greater suppression in plasma and renal G6PDH-dependent antioxidant index, adenosine, and aggravation of LDH, MDA compared with the NP+F group (p < 0.05). Sodium acetate reduces plasma and renal surrogate oxidative stress markers, improved G6PD-dependent antioxidant index, and HOMA-IR in NP+F and P+F groups. Pregnancy exacerbates fructose-induced insulin resistance and renal oxidative stress whereas acetate ameliorated fructose-induced redox and glucose dysregulation in pregnant and non pregnant rats.
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    Sodium acetate and androgen receptor blockade improve gestational androgen excess-induced deteriorated glucose homeostasis and antioxidant defenses in rats: Roles of adenosine deaminase and xanthine oxidase activities
    (Elsevier, 2018-08-29) Usman, Taofeek Oluwamayowa; Areola, Emmanuel Damilare; Badmus, Olufunto; Kim, InKyeom; Olatunji, Lawrence Aderemi
    Nutritional challenges and androgen excess have been implicated in the development of gestational diabetes and poor fetal outcome, but the mechanisms are not well delineated. The effects of short chain fatty acid (SCFA) on glucose dysmetabolism and poor fetal outcome induced by gestational androgen excess is also not known. We tested the hypothesis that blockade of androgen receptor (AR) and suppression of late gestational androgen excess prevents glucose dysmetabolism and poor fetal outcome through suppression of adenosine deaminase (ADA)/xanthine oxidase (XO) pathway. Twenty-four pregnant Wistar rats were treated (sc) with olive oil, testosterone propionate (0.5 mg/kg) singly or in combination with SCFA (sodium acetate; 200 mg/kg; po) or AR blocker (flutamide; 7.5 mg/kg; po) between gestational days 14 and 19. The results showed that late gestational androgen excess led to glucose deregulation, poor fetal outcome, increased plasma and hepatic free fatty acid and lactate dehydrogenase, liver function marker enzymes, malondialdehyde, uric acid, ADA and XO activities. Conversely, gestational androgen excess resulted in reduced body weight gain, visceral adiposity, plasma and hepatic anti-oxidant defenses (glutathione peroxidase, reduced glutathione/glutathione disulphide ratio, glucose-6-phosphate dehydrogenase, adenosine and nitric oxide). However, all these effects were ameliorated by either sodium acetate or flutamide treatment. The study demonstrates that suppression of testosterone by SCFA or AR blockade protects against glucose deregulation and poor fetal outcome by improvement of anti-oxidant defenses and replenishment of hepatic oxidative capacity through suppression of ADA/XO pathway. Hence, utility of SCFA should be encouraged for prevention of glucose dysmetabolism and poor fetal outcome.
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    Treatment with acetate during late pregnancy protects dams against testosterone-induced renal dysfunction
    (Elsevier, 2021-01-05) Olatunji, Lawrence Aderemi; Areola, Emmanuel Damilare; Usman, Taofeek Oluwamayowa; Badmus, Olufunto; Olaniyi, Kehinde Samuel
    Cardiometabolic diseases are complicated by renal damage. Gestational hyperandrogenism causes gestational metabolic dysfunction that is associated with fetal and maternal tissue derangements as well as post-partum maternal androgen excess. Acetate (Ace) conferred hepatoprotection in pregnant rats exposed to excess testos terone (Tes). The effect of excess androgenic exposure on maternal kidney during and after pregnancy is not clear. Therefore, this study investigated the effect of late gestational and post-gestational testosterone exposure on renal functions and plausible renoprotective role of gestational Ace treatment in dams. Thirty pregnant Wistar rats were grouped (n ¼ 10/group) and treated (sc) with olive oil, testosterone propionate (0.5 mg/kg) with or without acetate (200 mg/kg sodium acetate; p.o) between gestational days 14 and 19. Data were obtained from half of the animals on gestational day 20. Data were also obtained from the other half (dams) after treatment of animals which received Tes with or without prior gestational acetate treatment with post-gestational Tes (sc; 0.5 mg/kg) for the last 6 days of an 8-week postpartum period. Biochemical and statistical analyses were performed with appropriate methods and SPSS statistical software respectively. Late gestational excess Tes led to low placental weight (p ¼ 0.0001, F ¼ 205.7), poor fetal outcomes, creatinine (p ¼ 0.0001, F ¼ 385.4), urea (p ¼ 0.0001, F ¼ 300.9) and renal uric acid (UA) (p ¼ 0.0001, F ¼ 123.2), gamma-glutamyl transferase (GGT) (p ¼ 0.004, F ¼ 26.9), malondialdehyde (p ¼ 0.0001, F ¼ 45.96), and lactate dehydrogenase (LDH) (p ¼ 0.0002, F ¼ 150.7). Postpartum Tes exposure also caused elevated plasma testosterone (p ¼ 0001, F ¼ 22.15), creatinine (p ¼ 0.0002, F ¼ 15.2), urea (p ¼ 0.01, F ¼ 13.8) and renal UA (p ¼ 0.0001, 226.8), adenosine deaminase (p ¼ 0001, F ¼ 544.7), GGT (p ¼ 0.0002, F ¼ 401.4) and LDH (p ¼ 0.01, F ¼ 23.7). However, gestational acetate treatment ameliorated the renal effects of gestational and post-gestational Tes exposure. Taken together, gestational acetate would pre-programme dams against renal dysfunction caused by Tes exposure.
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    Uric acid is a key player in salt-induced endothelial dysfunction: the therapeutic role of Stigma maydis (corn silk) extract
    (Canadian Journal Publishing, 2019-06-03) Oyabambi, Adewumi Oluwafemi; Areola, Emmanuel Damilare; Olatunji, Lawrence Aderemi; Soladoye, Ayodele Olufemi
    Hyperuricemia has been implicated in the pathogenesis and complications of cardiovascular diseases with associated elevated oxidant events. There is evidence that excessive salt intake results in cardiometabolic disturbances but the mechanism is elusive. Also, Stigma maydis (corn silk) is noted for its antioxidant properties among other beneficial roles. This study, therefore, aimed to establish the effect of high-salt diet (SD) on uric acid (UA) production and the role of S. maydis in salt-induced phenotypes. Four groups of randomly selected rats (n = 5) were fed with normal rat feed, corn silk extract (500 mg/kg), SD (8%) and corn silk extract plus high-salt feed. After 6 weeks of the experimental procedure, each animal was anesthetized by exposure to chloroform vapor and blood samples collected by cardiac puncture. Data were expressed in means ± SEM and p values <0.05 were accepted as significant. SD resulted in reduced plasma superoxide dismutase (SOD), nitric oxide (NO), and glutathione peroxidase (GPx) but not endothelial nitric oxide synthase. Also, plasma UA and vascular cell adhesion molecule-1 (VCAM-1) increased in the SD group compared with control. However, S. maydis extract in the SD-exposed group increased NO and GPx and not SOD. Also, S. maydis extract attenuated UA and VCAM-1. In conclusion, high-salt intake may initiate deleterious cardiovascular events through UA-dependent mechanism and S. maydis extract has therapeutic potential in high-salt-induced oxidative damage and/or UA-dependent endothelial pathologies.