Genotoxicity and histopathological assessment of raw and simulated leachates exposed to mice

Indiscriminate solid waste disposal to the environment without proper treatment poses a serious threat to the public health. This study was carried out to investigate genotoxicity of the raw and simulated leachates samples collected from Amilegbe municipal dump site located in Ilorin metropolis in Nigeria. Some of the physicochemical properties of both raw and simulated leachate samples were determined. Mice were exposed to 1%, 2.5%, 5%, 10% and 25% (raw leachate) and 1%, 5% and 10% concentrations (simulated leachate) respectively for 35 days. Distilled water and colchicine were used for negative and positive control respectively. Two standard genotoxicity tests namely abnormal sperm-head morphology and micronucleus (MN) assays were used to assess possible genotoxicity of the raw and simulated leachates samples. Sperm head morphology assay showed some abnormalities (folded, amorphous, banana shaped, two tails, pin tail among others) and the frequencies of the abnormalities increases was concentrationdependent. Congestion, necrosis, degeneration and appearance of vacuolation were observed in the histopathological analysis of the liver. The histopathological changes were also more pronounced with higher concentrations of raw and simulated leachates. MN and abnormal nuclei frequencies also showed statistically significant differences (p>0.05) such that MN and other nuclear abnormalities reached the maximum at the highest concentration (25% >10% >5% >2.5%>1%). This study shows that the raw and simulated leachates contain potentially genotoxic and cytotoxic substances capable of causing DNA damage.Keywords: leachates; sperm head morphology assay; histopathology; blood; micronucleu

Role of nitric oxide and endogenous antioxidants in thyroxine facilitated healing of ischemia-reperfusion induced gastric ulcers

Background: Studies have revealed the role of thyroxine during healing of gastric ulcers with information lacking on the mechanism involved hence the focus of this study.Materials and Methods: Adult male Wistar rats (150 – 200g) were randomly divided into 4 groups (n=5 per group): Normal control (NC), Sham ulcerated (SU), Thyroidectomised ulcerated untreated (ThU) and Thyroidectomised ulcerated + Levo-thyroxine (100μg/kg/day) (ThU + T4). Animals were stabilised for 35 days following thyroidectomy and treated accordingly to experimental groupings. Weekly body weight changes were recorded, gastric ulcer was induced by ischemia-reperfusion and gastric acid secretion evaluated. They were sacrificed 1 hour, 3 and 7 days post ulcer induction, blood samples collected for haematological indices through cardiac puncture and their stomachs prepared for gross and microscopic examinations to assess gastric healing. Gastric tissue protein, malondialdehyde (MDA), Superoxide Dismutase (SOD), Catalase (CAT), and Nitric oxide (NO) were assessed as biomarkers of healing. Data were analysed using one way ANOVA and Student’s t test with p< 0.05 considered statistically significant.Results: Thyroxine treated rats showed significant weight loss compared with NC and ThU groups. Percentage healing rate was significantly increased in thyroxine treated group compared with ThU animals by 1 hour (42.45% and -42.81%), days 3 (35.14% and -59.36%), and 7 (64.29% and -115.7%). Hematological indices significantly increased in thyroxine treated group compared with other groups. Thyroxine treatment significantly reduced Neutrophil/Lymphocyte; Platelet/NO as well as lipid peroxidation index in this study. Superoxide dismutase, CAT and NO increased significantly in thyroxine treated rats compared with other groups.Conclusion: Thyroxine treatment facilitates the healing of ischeamic-reperfused  gastric ulcers possibly by increasing NO activity which in turn causes increased vasodilatation and enhanced endogenous antioxidants at the ulcer sites.Keywords: Nitric Oxide, Antioxidants, Thyroidectomy, Levo-thyroxine, Ulcer healing

Comparative studies of genotoxicity and anti-plasmodial activities of stem and leaf extracts of Alstonia boonei (De Wild) in malaria-infected mice

Drug resistance in malaria infection is a serious public health challenge. Thus, scientific search for alternative treatment measures among the local medicinal plants is exigent. We therefore investigated the anti-plasmodial efficacy and genotoxicity of the methanolic leaf and stem extracts of Alstonia plant at varying concentration (200 mg/kg, 400 mg/kg and 600 mg/kg) in mice infected with chloroquine sensitive Plasmodium berghei. The phytochemical screening of the extract revealed that leaf sample contained significantly higher secondary metabolites, except saponins (p<0.05). Anti-plasmodial activities of the two extracts were duration and dose- dependent. Stem bark extract showed higher curative potential with inhibition rate of 56.71% at 400 mg/kg whereas, leaf extract was efficient at 600mg/kg with 52.15% inhibition rate. Stem bark extract at 400 mg/kg improved the enzymatic activities of the mice; it lowered serum ALT (6.88±4.42) and increased liver ALT (41.07±5.56). Similarly, 400 mg/kg leaf extract showed highest AST (70.65±4.00) and ALT (44.65±7.83) activities in the kidney and liver respectively. Analysis of genotoxicity revealed that micronucleus and abnormal (binucleated, notched and blebbed) were prevalent among the experimental mice which increased significantly (p<0.05) at all concentrations except at 600mg/kg leaf extract. Therefore, this present study indicates that both leaf and stem bark extracts of A. boonei possess anti-plasmodial activity and are less genotoxic when compared with standard drug.Keywords: Genotoxicity; Plasmodium berghei; metabolites; micronucleus; blebbed; standard dru

Bayesian principal component analysis of Nigerian indigenous normal feather chickens' body linear measurements

The indigenous chicken is a store house of unique genes that  could be used in other parts of the world for improving other  breeds. This study was carried out using bayesian principal component analysis and aimed objectively at determining the effect of sex on Nigerian indigenous normal feather chickens' body dimension, describing their body shape, and predicting their body weights from body measurements using orthogonal  conformation traits derived from the principal components score. The parameters measured at 16 weeks of age were body weight, body length, breast girth, thigh length, shank length, shank diameter, keel length, wing length, wing span, and tail length on 233 randomly selected adult  chickens. Sexual dimorphism was observed in all the traits with higher values recorded for males. Bayesian correlations among body weight and biometric traits were positive (r = 0.09 to 0.651 and 0.017 to 0.579 in male and female chickens respectively). The descriptive statistics showed that the mean body weight was 1.8085 ± 0.263 kg for males and 1.403 ± 0.226 kg for females. The first two principal components (PCs) were extracted for the males, both PCs components account for 72.21%. For the females, three PCs were extracted and they  ccount for 77%. The first PC in each case accounted for the greatest percentage of the total variation. The use of orthogonal body shape characteristics derived from components' scoreswas more appropriate than the use of original traits in body weight prediction as multicollinearity problems were eliminated. This led to simultaneous analysis of these body measurements rather than on individual basis. These components could be used as selection criteria for improving body weight of indigenous Nigerian chickens. Keywords: Body weight, Body dimensions, Chickens, Orthogonal and biometric trait