Physiological Variations in Cucurbita moschata Duch. Ex. Poir Due to a Nigerian Strain of Moroccan Watermelon Virus: Lagenaria breviflora Isolate

Aim: Physiological variations in Cucurbita moschata due to infection with a Nigerian strain of Moroccan watermelon virus (MWMV): Lagenaria breviflora isolate was studied. Study Design: Randomized block design was used. Place and Duration of Study: Botany Department, University of Calabar, Calabar, Nigeria between March and May, 2015. Methodology: Seeds of C. moschata were sown, on germination inoculated with the virus and analyzed for possible variations between healthy and inoculated plants. Results: Results analysis revealed increase in all amino acids investigated. Highest significant (P=0.05) percentage variation in amino acids of inoculated and healthy were -40.0% for aspartic acid, -36.1% (histidine), -29.7% (proline), -28.8% (lysine), -23.3% (glysine), -16.6% (phenylalanine) and -12.6% (glutamic acid). Infection of C. moschata with a Nigerian Strain of MWMV: Lagenaria breviflora isolate caused significant decrease in leaf nitrogen and relative water content of inoculated plants compared to the healthy. Highest percentage decrease in leaf nitrogen was 40.7% at 2 weeks after inoculation (WAI) and lowest of 25.0% at 10 WAI. The virus caused decrease in relative water content of 29.6% at 6 WAI. Activity of oxidative stress enzymes: peroxidase (POD) and polyphenol oxidase (PPO) and enzymes of the oxidative pentose phosphate pathway: glucose-6-phosphate dehydrogenase (6PGdH) and 6-phosphogluconic acid dehydrogenase (G6PdH) were significantly (P=0.05) increased in infected C. moschata- MWMV plant. Enzymes activity was significantly higher in inoculated than in healthy plants at all stages of growth with decrease at later periods for both inoculated and healthy plants. Percentage increase in POD, PPO, G6PdH and 6PGdH activity due to infection at 8 WAI had values of -40.5%, -46.7%, -98.9% and -89.1% respectively. Conclusion: The Nigerian strain of MWMV: Lagenaria breviflora isolate caused significant variations with increase and decrease in biochemical and physiological components of C. moschata affecting its growth and yield.

In vitro Antiplasmodial Activity and Cytotoxicity of Vincadifformine and Its Semisynthetic Derivatives

An indole alkaloid with aspidospemane structure possessing a potential antiplasmodial activity,vincadifformine, has been isolated from Aspidosperma pyrifolium Mart. Moreover, 10 derivatives were preparedfrom the vincadifformine. The study was conducted to evaluate the in vitro antiplasmodial and cytotoxic activity ofthe vincadifformine and their semisynthetic derivatives. The in vitro antiplasmodial activity was evaluated onPlasmodium falciparum chloroquine-resistant (FcM ) and –sensitive (Nigerian) strains after 24-h and 72-h incubation, 29while cytotoxic activity was estimated on Hela cells and Cytotoxicity Index (CI = IC on HeLa cells/IC on FcM strain) 50 50 29was calculated to evaluate the safety of tested compounds. Experiment results showed that two compounds (4 and 8)exhibited good antiplasmodial activities in comparison with parent compound, vincadifformine and other testedcompounds with IC ranging from 5.3 to 12.8 μM on FcM strain and 11.4 to 24.0 μM on Nigerian strain. In addition, 50 29the CI of two compounds were also lower after 24-h incubation (CI, 2.0 and 4.8) than that of after 72-h incubation (CI,9.5 and 11.5). Further study will be conducted to evaluate quantitative structure-activity relationship (QSAR) in orderto design new antimalarial drugs.Keywords : vincadifformine - antiplasmodial – Plasmodium falciparum – cytotoxic - HeLa

The Structure of Maize Streak Virus: Are Two Heads Better Than One?

The geminiviruses are a group of plant DNA viruses characterized by having one or two copies of a single-stranded, circular DNA genome and frequent occurrence of geminate, quasi-isometric particles as observed by transmission electron microscopy. The Geminiviridaefamily is classified into three genera (Mastrevirus, Curtovirus and Begomovirus)based on the number of DNA components, the plant hosts, and the transmission vectors. Maize streak virus (MSV), the type member of the Mastrivirusgenus, is transmitted by the leafhopper and infects Gramineaespecies. Wheat dwarf virus, Digitaria streak virus, and Chloris striate mosaic virus (CSMV) are examples of other members of the Mastrivirusgenus. The Nigerian strain of MSV (MSV-N) contains one copy of a singlestranded, circular DNA molecule (2687 nucleotides). Two protein products, VI and V2, are coded by the MSV-N genome.2 V2 (244 amino acids) is the only coat protein found in virions.

Schistosoma haematobium: the effect of Astiban on the cell composition and ultrastructure of the vitelline gland and the ultrastructure of the tegument and gastrodermis

ABSTRACTTreatment of Schistosoma haematobium (Nigerian strain) in hamsters with a single dose of 40 mg/kg of Astiban caused a reduction in the number of S1, S2, and S3 vitelline cells and an increase in S4 cells. Following seven daily doses of the drug, a marked reduction in S1 cells and a complete loss of S2 and S3 cells occurred such that 95% of the cells were S4 cells, all of which were structurally abnormal. Coagulation and disintegration of the protein granules of the vitelline droplets occurred with increase in lipid droplets, swelling of the nuclear membrane and an increase in cytosegresomes. Blebbing of the tegument in both sexes occurred following a single treatment and vacuolation of the basal infolds and alterations to the mitochondria also resulted, but severe erosion of the tegument was rare even following repeated drug treatment. Damage to the gastrodermis was severe with the development of autophagic vacuoles containing whorls of myelin and sequestered portions of damaged tissue. The degree of damage increased with the number of drug treatments.