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ABSTRACT: The effect of dried fruit extract from Xylopia aethiopica (Annonaceae) (XA) and vitamin C (VC) against γ-radiation-induced liver and kidney damage was studied in male Wistar rats. XA and VC were given orally at a dose of 250 mg/kg, orally for 6 weeks prior to and 8 weeks after radiation (5 Gy). The rats were sacrificed after 1 and 8 weeks of single exposure to radiation. Results showed that all animals in un-irradiated group survived (100%), while 83.3% and 66.7% survived in XA- and VC-treated groups, respectively, and 50% survived in irradiated group. The levels of serum, liver and kidney lipid peroxidation (LPO) were elevated by 88%, 102% and 73% after 1 week of exposure, and by 152%, 221% and 178%, after 8 weeks of exposure, respectively. Treatment with XA and VC significantly (p<0.05) decreased the levels of LPO in the irradiated animals. Also, γ-radiation caused significant decreases (p<0.05) in the levels of liver glutathione (GSH), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), kidney GSH and SOD by 41%, 60%, 81%, 79%, 72% and 58% after 1 week of exposure. Similarly, γ-radiation caused significant increases (p<0.05) in the levels of serum alanine (ALT) and aspartate aminotransferases (AST) after 8 weeks of exposure. Precisely, ALT and AST levels were increased by 69% and 82%, respectively. These changes were significantly (p<0.05) attenuated in irradiated animals treated with XA and VC. These results suggest that XA and VC could increase the antioxidant defence systems in the liver and kidney of irradiated animals, and may protect from adverse effects of whole body radiation.
Experimental and toxicologic pathology: official journal of the Gesellschaft fur Toxikologische Pathologie 11/2011; 63(7-8):635-43. · 1.43 Impact Factor
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ABSTRACT: The antimalarial and antioxidant activities of methanolic extract of Nigella sativa seeds (MENS) were investigated against established malaria infection in vivo using Swiss albino mice. The antimalarial activity of the extract against Plasmodium yoelli nigeriensis (P. yoelli) was assessed using the Rane test procedure. Chloroquine (CQ)-treated group served as positive control. The extract, at a dose of 1.25 g/kg body weight significantly (p<0.05) suppressed P. yoelli infection in the mice by 94%, while CQ, the reference drug, produced 86% suppression when compared to the untreated group after the fifth day of treatment. P. yoelli infection caused a significant (p<0.05) increase in the levels of red cell and hepatic malondialdehyde (MDA), an index of lipid peroxidation (LPO) in the mice. Serum and hepatic LPO levels were increased by 71% and 113%, respectively, in the untreated infected mice. Furthermore, P. yoelli infection caused a significant (p<0.05) decrease in the activities of superoxide dismutase, catalase, glutathione-S-transferase and the level of reduced glutathione in tissues of the mice. Treatment with MENS significantly (p<0.05) attenuated the serum and hepatic MDA levels in P. yoelli-infected mice. In addition, MENS restored the activities of red cell antioxidant enzymes in the infected mice to near normal. Moreover, MENS was found to be more effective than CQ in parasite clearance and, in the restoration of altered biochemical indices by P. yoelli infection. These results suggest that N. sativa seeds have strong antioxidant property and, may be a good phytotherapeutic agent against Plasmodium infection in malaria.
Parasitology Research 12/2010; 108(6):1507-12. · 2.15 Impact Factor
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ABSTRACT: Ionizing radiation is one of the environmental factors that may contribute to reproductive dysfunction by a mechanism involving oxidative stress. We investigated the possible ameliorative effects of kolaviron (KV) (a biflavonoid from the seeds of Garcinia kola) on sperm characteristics, testicular lipid peroxidation (LPO) and antioxidant status after a whole body γ-irradiation in Wistar rats. Vitamin C (VC) served as standard antioxidant in this study. The study consists of four groups of 6 rats each. Group I received corn oil, whereas group II received a single dose of γ-radiation (5 Gy). The animals in groups III and IV were pretreated with KV (250 mg/kg) and VC (250 mg/kg) by oral gavage five times in a week, respectively, for 6 weeks prior to and 8 weeks after exposure to γ-radiation. Gamma-irradiation resulted in a significant (p<0.05) decrease in body weight and relative testes weight. Also, γ-irradiation significantly (p<0.05) decreased the activities of superoxide dismutase, catalase and glutathione S-transferase as well as glutathione level, but markedly elevated malondialdehyde levels in the serum and testes. Irradiated rats showed testicular degeneration with concomitant decrease in sperm motility and viability. Although sperm abnormalities significantly increased, it has no effect on the epididymal sperm count. KV and VC significantly (p<0.05) decreased the body weight loss and increased relative testes weights of the rats. Furthermore, supplementation of KV and VC ameliorated radiation-induced toxicity by increasing the activities of antioxidant enzymes, decreased LPO and abrogated testicular degeneration. Taken together, γ-irradiation caused reproductive dysfunction by depleting the antioxidant defence system in the rats, while administration of KV or VC ameliorated the radiation-induced testicular toxicity.
Experimental and toxicologic pathology: official journal of the Gesellschaft fur Toxikologische Pathologie 10/2010; 64(4):379-85. · 1.43 Impact Factor
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ABSTRACT: The antioxidant and scavenging properties of kolaviron, a flavonoid extract of Garcinia kola seeds, were evaluated in a series of in vitro assays involving free radicals and reactive oxygen species. Kolaviron exhibited markedly reducing power and antioxidant activity by inhibiting the peroxidation of linoleic acid. Kolaviron exhibited 57% scavenging effect on superoxide at a concentration of 1 mg/ml and 85% scavenging effect on hydrogen peroxide at a concentration of 1.5 mg/ml. Similarly, kolaviron, at a concentration of 2 mg/ml, elicited an 89% scavenging effect on a,a-diphenyl-ß-picrylhydrazyl radical, indicating that the extract has effective activities as a hydrogen donor and as a primary antioxidant to react with lipid radicals. Kolaviron reacted with hydroxyl radical (·OH) by inhibiting deoxyribose oxidation induced by a Fenton-type reaction system (Fe 3+ + EDTA/H 2 O 2 /ascorbic acid). The second-order rate constant for the reaction with ·OH was approximately 1.1 × 10 10 M -1 sec -1. Kolaviron was effective at preventing microsomal lipid peroxidation induced by iron/ascorbate in a concentration dependent manner. The overall antioxidant activity of kolaviron on lipid peroxidation might be attributed to its properties of scavenging free radicals and active oxygen species and may relate directly to prevention of propagation of in vivo lipid peroxidation.
09/2008; 40(2):107-116.
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ABSTRACT: The present study reports the protective effects of kolaviron, a Garcinia biflavonoid from the seeds of Garcinia kola widely consumed in some West African countries against oxidative damage to molecular targets ex-vivo and in vitro. Treatment with hydrogen peroxide (H2O2) at a concentration of 100 micromol/L increased the levels of DNA strand breaks and oxidized purine (formamidopyrimidine glycosylase (FPG) and pyrimidine (endonuclease III (ENDO III) sites) bases in both human lymphocytes and rat liver cells using alkaline single cell gel electrophoresis (the comet assay). Kolaviron was protective at concentrations between 30-90 micromol/L and decreased H2O2-induced DNA strand breaks and oxidized bases. Neither alpha-tocopherol nor curcumin decreased H2O2-induced DNA damage in this assay. In lymphocytes incubated with Fe3+/GSH, Fe3+ was reduced to Fe2+ by GSH initiating a free radical generating reaction which induced 11.7, 6.3, and 4.9 fold increase respectively in strand breaks, ENDO III and FPG sensitive sites compared with control levels. Deferoxamine (2 mmol/L), an established iron chelator significantly inhibited GSH/Fe3+-induced strand breaks and oxidized base damage. Similarly, kolaviron at 30 and 90 micromol/L significantly attenuated GSH/Fe3+-induced strand breaks as well as base oxidation. Kolaviron (100 mg/kg bw) administered to rats for one week protected rat liver cells against H2O2-induced formation of strand breaks, ENDO III, and FPG sensitive sites, Fe3+/EDTA/ascorbate-induced malondialdehyde formation and protein oxidation using gamma-glutamyl semialdehyde (GGS) and 2-amino-adipic semialdehyde (AAS) as biomarkers of oxidative damage to proteins. We suggest that kolaviron exhibits protective effects against oxidative damage to molecular targets via scavenging of free radicals and iron binding. Kolaviron may therefore be relevant in the chemoprevention of oxidant-induced genotoxicity and possibly human carcinogenesis.
Cell Biology and Toxicology 04/2004; 20(2):71-82. · 2.51 Impact Factor
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ABSTRACT: The antioxidant activities of the leaf and root extracts of Alchornea laxiflora, a plant used locally for the preservation of food items in Nigeria, were evaluated using the ferric thiocyanate method, horseradish peroxidase catalysed oxidation of 2,2 azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), beta-carotene linoleate model system and Fe(2+)/ascorbate/H(2)O(2)-induced rat liver microsomal lipid peroxidation. The crude hexane root (HR), methanol root (MR), methanol leaf (ML) and hexane leaf (HL) extracts from A. laxiflora were tested for antioxidant activities. Antioxidant activity decreased in the following order: HR (76.4%), MR (63%), ML (40%) and HL (38%) at a concentration of 0.05% v/v. The antioxidant activity of HR compared to that of butylated hydroxyanisole (BHA) (80%), a standard antioxidant. The total antioxidant activity (TAA) of the crude extracts suggests that activity is highest in the HR compared with the others. The TAA value was estimated to be 8.0 measured as mm of vitamin C equivalent. Six column chromatographic fractions (FI-FVI) from HR showed antioxidant activity to varying extents in the beta-carotene model system in the order of FII > FI > FVI > FIII > FIV > FV. FII exhibited the highest antioxidant activity in all model systems utilized, it recorded a higher antioxidant activity than BHA and quercetin in the beta-carotene linoleate and Fe(2+)/ascorbate/H(2)O(2). TLC analysis of fraction II revealed the presence of terpenoid compounds (radiant green coloration with 2,4 dinitrophenylhydrazine). Our results suggest that A. laxiflora contains potent natural antioxidants and may therefore be relevant in the preservation of lipid food products, which are prone to oxidation and rancidity.
Phytotherapy Research 08/2003; 17(7):713-6. · 2.09 Impact Factor
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ABSTRACT: It is known that malaria infection is accompanied by increased production of reactive oxygen species (ROS) and that malaria parasites are sensitive to oxidative damage. This has been proved by the efficacy of some antimalarial drugs that are known to act via generation of ROS when administered clinically or experimentally.
There is lack of information on the effect of chloroquine on the antioxidant defense systems of normal and malaria infected humans. Since chloroquine has remained the mainstay of therapeutic regimen in malaria endemic zones, the present investigation was therefore undertaken to study the status of blood antioxidant defense mechanism, and oxidative stress following chloroquine treatment in normal and plasmodium infected humans.
Ten healthy persons (5 males and 5 females) with the same age range (18-35 years) were taken as control group. Ten other individuals were treated with 25 mg/kg body with chloroquine over three days. Ten patients with malaria, not under antimalarial therapy were taken as another group, while another set of 10 patients with malaria were treated with 25 mg/kg body weight over three days.
The activity of superoxide dismutase was increased by 23% in individuals treated with chloroquine compared to controls while the activity of the enzyme decreased by 26% in malaria patients and by 43% in malaria patients treated with chloroquine. In all the treatment groups, the activities of catalase and glutathione peroxidase were lowered (P < 0.001). Similarly the levels of vitamins A, C, and beta-carotene were decreased in the treatment groups while plasma ceruloplasmin was increased in the groups. Glutathione and cholesterol levels were decreased while malondialdehyde level was increased significantly.
Chloroquine treatment mediated oxidative stress in the host and this effect was exacerbated in Plasmodium falciparum infected patients administered with the drug.
Drug and Chemical Toxicology 02/2003; 26(1):59-71. · 1.08 Impact Factor
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ABSTRACT: The effects of chloramphenicol and antioxidant vitamins on in vivo and in vitro indices of microsomal drug oxidizing system were examined in rats. Chloramphenicol at doses of 28 mg/kg, 57 mg/kg and 86 mg/kg body weight administered for 10 consecutive days resulted in a dose-dependent decrease in body weight, liver weight, relative liver weight and protein content compared to control. Chloramphenicol treatment also resulted in a dose-dependent decrease in microsomal phospholipid and a significant increase in cholesterol content causing an increase in cholesterol/phospholipid molar ratio. The drug produced a significant reduction in the activity of aniline hydroxylase, aminopyrine N-demethylase, p-nitroanisole O-demethylase and ethoxyresorufin O- deethylase. Activity of ethoxyresorufin O-deethylase was little affected by the drug. Chloramphenicol ranging from 10-4-10-6 M similarly produced a concentration dependent inhibition in the activities of the enzymes. Kinetic studies revealed that chloramphenicol inhibited the enzymes non-competitively. alpha-Tocopherol, beta-carotene and ascorbic acid decreased the chloramphenicol inhibition of the enzymes within the range of 70 to 81%, 45-63% and 55 to 75% respectively. Also, the antioxidant vitamins attenuated the chloramphenicol-induced formation of malondialdehyde by 60%, 53% and 56% and lipid hydroperoxide by 60%, 54%, and 54% respectively The results indicate that the effect of chloramphenicol on cytochrome P450 drug oxidizing enzyme components is related to the action of the drug presumably, via free radical mechanism and that co-administration with antioxidant vitamins can attenuate its toxic action.
Pharmacology & Toxicology 10/2002; 91(3):129-34.
