Genetic diversity and population structure of Striga hermonthica populations from Kenya and Nigeria

Article purchasedStriga hermonthica is a parasitic weed that poses a serious threat to the production of economically important cereals in sub-Saharan Africa. The existence of genetic diversity within and between S. hermonthica populations presents a challenge to the successful development and deployment of effective control technologies against this parasitic weed. Understanding the extent of diversity between S. hermonthica populations will facilitate the design and deployment of effective control technologies against the parasite. In the present study, S. hermonthica plants collected from different locations and host crops in Kenya and Nigeria were genotyped using single nucleotide polymorphisms. Statistically significant genetic differentiation (FST = 0.15, P = 0.001) was uncovered between populations collected from the two countries. Also, the populations collected in Nigeria formed three distinct subgroups. Unique loci undergoing selection were observed between the Kenyan and Nigerian populations and among the three subgroups found in Nigeria. Striga hermonthica populations parasitising rice in Kenya appeared to be genetically distinct from those parasitising maize and sorghum. The presence of distinct populations in East and West Africa and in different regions in Nigeria highlights the importance of developing and testing Striga control technologies in multiple locations, including locations representing the geographic regions in Nigeria where genetically distinct subpopulations of the parasite were found. Efforts should also be made to develop relevant control technologies for areas infested with ‘rice-specific’ Striga spp. populations in Kenya

Sub-acute toxicity study of ethylene glycol monomethyl ether on the antioxidant defense system of the testes and epididymes of wistar rats

Summary: Ethylene glycol monomethyl ether is a toxicant with wide industrial applications. This study is aimed at investigating its effect on the antioxidant system of the reproductive organs of male rats. Fifty male Wistar rats were distributed into five groups. Group I received distilled water, Groups II-V received EGME at 100, 200, 300 and 400 mg/kg body weight respectively. All administrations were done orally for fourteen days and the weight was monitored weekly. On day fifteen, the animals were sacrificed and reproductive organs were collected and weighed. The testes and epididymes were processed for the biochemical estimations, histopathology and spermatozoa analysis. The percentage body weight gained weekly and the relative weight of the testes reduced significantly (p < 0.05) in the treatment groups. The spermatozoa analysis showed decreases in the treatment groups. In the testis and epididymis, various antioxidant parameters such as superoxide dismutase and glutathione-S-transferase were affected. The histopathology results confirmed the biochemical findings. The study suggests that EGME exerts deleterious effects on the testes and epididymes by increasing the oxidative load in rats.Keywords: Ethylene glycol monomethyl ether, Antioxidant defense, Spermatozoa, epididymes, testesNiger. J. Physiol. Sci. 33(December 2018) 195-20

Evaluation of days-dependent chloramphenicol dosage on rat liver microsomal lipid peroxidation and catalase activity

Drugs and chemical agents can alter the cellular functions associated with the oxidative metabolism, thereby stimulating ROS production. The objective of the this study was the in vivo study of the inhibitory effect of chloramphenicol on hepatic microsomal enzyme system and the effect on lipid peroxidation using the thiobarbituric acid (TBA) reactive as index of peroxidation damage was investigated. The rats were randomly divided into 3 groups; group 1 serves as the control receiving saline water, group 2 receive chloramphenicol at a dose of 28.6 mg/kg body weight/day for 5 days and group 3 for 7 days. Liver protein content, lipid hydroperoxides and catalase activity were all determined. TBARS concentration increased statistically significantly with time of exposure. After 5 days of treatment, the level of TBARS increased by 103.56% with exogenous oxidant and by 141.54% for without oxidant, as compared to the respective control. On day 7, TBARS level in the liver was approximately 90.75% higher than in the control group with oxidant and 117.03% higher than the control without oxidant. The antibiotic elicited significant increase in rat liver lipid peroxidation compared to control. There were decreases in microsomal protein content of the liver in the drug-treated rats when compared with the control rats. It also showed that chloramphenicol treatment affects cytosolic catalase activities. It decreases catalase levels by 15.75% in 5 days dosage treatment and 17.81% in 7 days dosage treatment respectively. There were significance difference (P<0.05) in the treated and control irrespective of the days of dosage. The catalase level in hepatocyte in 5 days and 7 days group was significance at p<0.01. In conclusion, it was evident that treatment of rats for 5 days and 7 days with the therapeutic doses of Chloramphenicol altered antioxidant system and the intensity of effects was concentration/dosage days dependent, it resulted in membrane lipid peroxidation, protein damage, and inhibition of microsomal catalase due to increased generation of free radicals, reactive oxygen species and reactive nitrogen speciesKeywords: Chloramphenicol, rat liver, lipid peroxidation, catalase activity, antioxidan