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ABSTRACT: This study investigated the ameliorative effects of kolaviron (a biflavonoid from the seed of Garcinia kola) and vitamin C on ethylene glycol monoethyl ether (EGEE)-induced oxidative damage in boar spermatozoa in vitro. EGEE (1.0 mm) was incubated with boar spermatozoa for 3 h with or without either kolaviron (50 and 100 μm) or vitamin C (1.0 mm). Spermatozoa parameters were determined hourly during the incubation period, whereas aminotransferases and alkaline phosphatase activities and oxidative stress indices were assessed after the incubation period. Results showed a time-dependent decline in spermatozoa motility and viability with significant elevation in total abnormalities in EGEE-treated spermatozoa. Exposure to EGEE resulted in significant increase in aminotransferases, alkaline phosphatase and superoxide dismutase (SOD) activities, whereas it markedly decreased glutathione (GSH) level, catalase (CAT) and glutathione S-transferase (GST) activities with concomitant increase in hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA) levels. Pre-treatment of spermatozoa with kolaviron or vitamin C significantly decreased H2 O2 and MDA levels, improved spermatozoa characteristics and ameliorated oxidative damage in EGEE-treated spermatozoa. Taken together, EGEE exhibited its spermatotoxicity via induction of oxidative stress. The protective effects by kolaviron and vitamin C against EGEE-induced oxidative damage may be due to their intrinsic antioxidative potentials.
Andrologia 04/2013; · 1.55 Impact Factor
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ABSTRACT: The study evaluated the protective role of kolaviron (an isolated biflavonoid from the seed of Garcinia kola) and vitamin E in carbendazim-induced reproductive dysfunction in male rats. Adult male Wistar rats were orally exposed to carbendazim (200mg/kg) singly or in combination with kolaviron (100 and 200mg/kg). Exposure to carbendazim significantly decreased the activities of superoxide dismutase and catalase but markedly increased sialic acid concentration and lipid peroxidation in the testes of rats. Western blot analysis revealed that carbendazim treatment decreased the expression of steroid acute regulatory (StAR) protein and androgen binding protein (ABP) with concomitant decrease in activities of steroidogenic enzymes. Germ cell apoptosis in carbendazim-treated rats was confirmed by TUNEL assay. However, pretreatment with kolaviron and vitamin E restored the testicular antioxidant status and steroidogenesis and decreased apoptotic nuclei to near control level in carbendazim-treated rats. Kolaviron may prove useful in combating carbendazim-induced reproductive toxicity.
Environmental toxicology and pharmacology. 02/2013; 35(3):444-453.
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ABSTRACT: Endocrine disrupting chemicals cause reproductive dysfunction by interacting with intricate regulation and cellular processes involve in spermatogenesis. This study investigated the probable mechanism of action of ethylene glycol monoethyl ether (EGEE) as an antiandrogenic compound as well as the effects of kolaviron upon co-administration with EGEE in rats. Adult male rats were exposed to EGEE (200 mg kg(-1) bw) separately or in combination with either kolaviron [100 (KV1) and 200 (KV2) mg kg(-1) bw] or vitamin E (50 mg kg(-1) bw) for 14 days. Western blot analysis revealed that the administration of EGEE adversely affected steroidogenesis in experimental rats by decreasing the expression of steroid acute regulatory (StAR) protein and androgen-binding protein (ABP). EGEE significantly decreased the activities of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) but markedly increased sialic acid concentration in rat testes. EGEE-treated rats showed significant decreases in plasma levels of luteinising hormone (31%), testosterone (57.1%), prolactin (80.9%), triiodothyronine (65.3%) and thyroxine (41.4%), whereas follicle-stimulating hormone was significantly elevated by 76.9% compared to the control. However, co-administration of kolaviron or vitamin E significantly reversed the EGEE-induced steroidogenic dysfunction in rats. This study suggests that kolaviron may prove promising as a chemoprotective agent against endocrine pathology resulting from EGEE exposure.
Andrologia 06/2012; · 1.55 Impact Factor
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ABSTRACT: This study evaluated the effects of kolaviron, a biflavonoid from Garcinia kola seed, and quercetin on cadmium-induced reproductive toxicity in rats. Adult male rats were administered with either cadmium (15 mg kg(-1)) alone or in combination with kolaviron (200 mg kg(-1)) or quercetin (10 mg kg(-1)) daily for 5 days. Cadmium-treated rats showed (P < 0.05) decrease in the body weight gain, testis and epididymis weights. However, upon co-administration of kolaviron or quercetin, these changes were significantly reversed in cadmium-treated rats. Also, administration of kolaviron or quercetin significantly prevented cadmium-mediated decrease in sperm motility and epididymal sperm concentration and reversed the increased level of sperm abnormality to near control. In testes and sperm, cadmium treatment resulted in significant decrease in the activities of superoxide dismutase, catalase and glutathione peroxidase, whereas it increased glutathione S-transferase activity as well as hydrogen peroxide and malondialdehyde levels. While plasma levels of triiodothyronine and tetraiodothyronine remained unaffected, the levels of testosterone, luteinising hormone and follicle stimulating hormone were decreased in cadmium-treated rats. Cadmium treatment caused mild congestion of interstitial vessels and oedema in the testes. Taken together, kolaviron and quercetin inhibited the adverse effects of cadmium on the antioxidant enzymes, markers of oxidative stress, endocrine and testicular structure in rats.
Andrologia 02/2012; 44(4):273-84. · 1.55 Impact Factor
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ABSTRACT: The present study investigated the protective effect of kolaviron, a biflavonoid from the seed of Garcinia kola, on ethylene glycol monoethyl ether (EGEE)-induced reproductive toxicity in male rats. The protective effect of kolaviron was validated using vitamin E, a standard antioxidant. EGEE was administered at a dose of 200 mg/kg. Other groups of rats were simultaneously treated with kolaviron (100 and 200 mg/kg) and vitamin E (50 mg/kg) for 14 days. EGEE treatment resulted in significant decrease in glutathione (GSH) level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities but markedly increased the glutathione-S-transferase (GST) and lactate dehydrogenase (LDH) activities in the testes. In the spermatozoa, administration of EGEE caused significant decrease in the activities of CAT, GPx, GST and LDH as well as in the level of GSH but significantly increased SOD activity with concomitant increase in hydrogen peroxide and malondialdehyde levels in both testes and spermatozoa. EGEE-exposed rats showed marked testicular degeneration with concomitant decrease in spermatozoa quantity and quality. Overall, EGEE causes reproductive dysfunction in rats by altering antioxidant systems in the testes and spermatozoa. Kolaviron or vitamin E exhibited protective effects against EGEE-induced male reproductive toxicity by enhancement of antioxidant status and improvement in spermatozoa quantity and quality.
Human & Experimental Toxicology 10/2011; 31(5):506-17. · 1.31 Impact Factor
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ABSTRACT: Human beings are more often exposed to complex mixtures of hazardous chemicals than single toxicant. The present study investigated the effects of Olushosun municipal landfill leachate (OMLL) from Ojota in Lagos State of Nigeria on hepatic function and some biomarkers of oxidative stress in adult rats. Physicochemical characteristic analysis of OMLL showed that while total alkalinity, total acidity, total hardness, biochemical oxygen demand and chemical oxygen demand were 3-fold, 2-fold, 4-fold and 1-fold, respectively, concentrations of heavy metals analysis showed that copper, lead, cadmium, arsenic, cobalt, chromium and mercury were 9-fold, 4-fold, 21-fold, 1320-fold, 7-fold, 5-fold and 4-fold, respectively, higher than acceptable limits by regulatory authorities. The OMLL was administered at 0, 10, 20, 30 and 40% concentrations to adult male rats for 14 days. Following exposure, serum was collected for serum biochemistry assays and liver was collected to determine the antioxidant status. Exposure of animals to 10, 20, 30 and 40% OMLL resulted in 3%, 31%, 52% and 83% increase in aspartate aminotransferase activity, whereas it elevated alanine aminotransferase activity by 10%, 25%, 30% and 49%, respectively, when compared with the control. While OMLL administration significantly increased catalase activity, a sequential decrease in reduced glutathione level and in superoxide dismutase and glutathione-S-transferase activities with concomitant increase in malondialdehyde level were observed, when compared with the control. Collectively, the hepatotoxicity of OMLL could be due to the induction of oxidative stress and may suggest possible health hazards in subjects with occupational or environmental exposure.
Toxicology and Industrial Health 09/2011; 28(6):532-41. · 1.42 Impact Factor
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ABSTRACT: The study was carried out to compare the effects of quercetin (QT) at doses of 5mg/kg (Q5) and 10mg/kg (Q10) against the hematological toxicity and oxidative stress caused by atrazine (ATR). Male rats were orally gavaged with ATR at a dose of 120mg/kg for 16 days. Erythropenia, leucopenia was observed in ATR treated rats. Other hematological variables such as packed cell volume (PCV), hemoglobin concentration (HGB), mean cell hemoglobin concentration (MCHC), mean corpuscular volume (MCV), neutrophils (NEU), lymphocytes (LYM) and blood platelet (PLT) showed no significant change with respect to the control values. The activities of the antioxidant defense molecules including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and glutathione (GSH) were decreased; malondialdehyde (MDA) level increased but catalase (CAT) activity showed no change.Co-administration of Q5 did not prevent the oxidative stress and the hematological alterations caused by ATR. In these groups of animals, the values of PLT and NEUT were increased while LYM decreased indicating more pronounce hematological changes. The changes in both the biochemical and hematological variables were normalized to the control values on co-administration of Q10. We suggest that the antioxidant activities of QT at a doses of 10mg/kg could be responsible for its protective effects against ATR-induced oxidative stress and hematological toxicity.
African journal of medicine and medical sciences 12/2010; 39 Suppl:81-8.
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ABSTRACT: The protective effect of antioxidants and naturally occurring substances against oxidative stress damage has recently attracted much attention. The leaves of Mallotus oppositifolium, a shrub of the family Euphorbiacea that grows in many parts of Africa, are used in folk medicine and herbal preparations for the treatment of dysentery, worms and malaria. The study investigated the antioxidant properties of the methanolic extract of the leaves of Mallotus oppositifolium (MEMO) in comparison with butylated hydroxyl anisole (BHA) as a standard antioxidant using three free radical generators viz hydrophilic radical generator 2,2-azobis(2-amidino propane) dihydrochloride (AAPH), hydrophobic radical generator 2,2-azobis(2,4-dimethylvaleronitrile) (AMVN) and hydroxyl radical and non-specific radical generator Fe2+/ascorbate system in an in vitro, in vivo and ex-vivo model systems. Phytochemical analysis of the leaves extract was also assessed. Phytochemical analysis of the powdered leaves revealed the presence of alkaloids, tannins, cardenolides and saponins. In vitro study indicated that while MEMO failed to inhibit lipid peroxidation (LPO) induced by AAPH, while BHA offered 55.5% inhibition. In addition, while AMVN-induced LPO was inhibited by 17.7% and 29.4% by MEMO and BHA respectively, Fe2+/ascorbate system-induced LPO was inhibited by 57.9% and 78.9% by MEMO and BHArespectively. Ex-vivo studies showed that MEMO at 100mg/kg bw reduced malondialdehyde and protein carbonyl levels by 34.5% and 12.0% respectively compared with the control. In vivo, MEMO increased (P<0.05) superoxide dismutase and catalase activities by 408.0% and 295.0% respectively. Taken together, this study demonstrates that MEMO exhibits antioxidant, radical scavenging and enhancement of enzymatic antioxidant capacity and as such could intervene in toxicological processes mediated by free radical mechanisms.
African journal of medicine and medical sciences 12/2010; 39 Suppl:67-72.
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ABSTRACT: The present study investigated the effects of aflatoxin B₁ (AFB₁) and ethanol co-exposure on biomarkers of hepatic damage in mice. Four groups of adult male mice were treated for 7 consecutive days. Control mice received corn oil alone at a dose of 2 mL/kg bw. One group was treated with ethanol at a dose of 500 µL/kg bw and another group administered 9 mg/kg bw of AFB₁ dissolved in corn oil. The fourth group was co-administered with ethanol and AFB₁. The body and liver weights of treated mice decreased significantly when compared with corresponding control. Alone, ethanol and AFB(1) treatment separately increased serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP). Alcohol dehydrogenase (ALD) activity was markedly elevated in ethanol-treated mice but was unaffected by AFB₁ treatment. Co-exposure of AFB₁ and ethanol escalated the activities of these serum enzymes. Administration of ethanol and AFB₁ separately resulted in significant decrease in both non-enzymatic antioxidant glutathione (GSH) level and enzymatic antioxidant catalase (CAT) and glutathione-S-transferase (GST) activities, whereas lipid peroxidation was markedly elevated. Superoxide dismutase activity and vitamin C level remained unaffected in all treatment groups. Co-exposure of animals to ethanol and AFB₁ showed additive effects on the activities of GST and CAT as well as on the GSH level. Histopathological study revealed that these compounds interact together to exacerbate their individual effects on the liver. In summary, the data presented showed that AFB₁ and ethanol co-exposure induced severe oxidative damage to the liver of mice and as such humans consuming excessive amount of ethanol and diets contaminated with AFB₁ simultaneously may be at greater risk of the hepatotoxic effects of these compounds.
Toxicology and Industrial Health 11/2010; 26(10):717-24. · 1.42 Impact Factor
