IN VITRO STUDY ON CYTOTOXIC EFFECTS OF THE ORGANOPHO SPHOROUS PESTICIDE PROFENOFOS ON THE GILL CELL LINE, FG-9307, OF THE FLOUNDER (PARALICHTHYS OLIVACEUS)

The FG 9307 cell line derived from the gill of flounder Paralichthys olivaceus was used in the present study to determine the acute cytotoxic effects of the organophosphorous pesticide, profenofos. It was found that the cell growth rate was markedly reduced by profenofos at the concentrations of 2.5, 5 and 7.5 mg/L tested; and that the fine structures of the cells were also altered by profenofos, as evidenced by dilation of nuclear membranes and mitochondria cristae, and presence of enlarged lysosomes with engulfed organelles and numerous vacuoles in the cytoplasm. Probably, mitochondria, the cell energy generating sites, are the most prominent sites of profenofos cytotoxity in the cells. This seems to be the first report of the use of marine fish cell line for evaluation of the acute in vitro cytotoxicity of organophosphorus pesticide.

Isolation and characterization of a profenofos degrading bacterium

Profenofos, a well known organophosphate pesticide, has been in agricultural use over the last two decades for controlling Lepidopteron pests of cotton and tobacco crops. In this study, a bacterial strain, OW, was isolated from a long term profenofos exposed soil by an enrichment technique, and its ability to degrade profenofos was determined using gas chromatography. The isolated strain OW was identified as Pseudomonas aeruginosa according to its physiological and biochemical properties, and the analysis of its 16S rRNA gene sequence. The strain grew well at pH 5.5-7.2 with a broad temperature profile. Bioremediation of profenofos-contaminated soil was examined using soil treated with 200 μg/g profenofos, which resulted in a higher degradation rate than control soils without inoculation. In a mineral salt medium （FTW）, removal in the level of profenofos of 86.81% was obtained within 48 h of incubation. The intermediates of profenofos metabolism indicated that the degradation occurred through a hydrolysis mechanism, and one of the metabolites was found to be 4 bromo-2-cholorophenol （BCP） which in turn was also mineralized by the strain. The results of this study highlighted the potentiality of P. aeruginosa as a biodegrader which could be used for the bioremediation of profenofos contaminated soil.

Efficiency of Botanical and Chemical Pesticides on the Control of Field Insect Pests under Cowpea Production

The pulse cowpea [Vigna unguiculata (L.) Walp] holds a significant agricultural position in Uganda, ranking fourth among legume crops, following common beans, groundnuts, and soybeans. Known for its versatility, cowpeas are consumable at various developmental stages, from early seedling to maturity. However, the crop faces persistent pest challenges at each stage, leading to substantial yield losses. In Uganda, chemical insecticides are the primary pest control means, but their increased and excessive use raises environmental, health, and economic concerns. This has prompted a quest for alternative and sustainable solutions, prompting an exploration of botanical insecticides. This study, conducted at Makerere University Agricultural Research Institute (MUARIK), aimed to evaluate the effectiveness of three selected botanical insecticides versus four established chemical insecticides for managing cowpea insect pests under field conditions. The treatments included: Carbofuran, Cypermethrin 10% EC, Dimethoate, Pestwin, Pyrethrum ewc , Pyrethrum 5ew, Profenofos 40% Cypermethrin 4% EC mix, and Untreated, arranged in a randomized complete block design with three replications. The significant pests studied were aphids, thrips, pod-sucking bugs, and legume pod borer. Results indicated substantial impacts of the treatments on pest infestation, with Profenofos 40% Cypermethrin 4% EC being the most effective against most pests. The plant parameter, plant height, was significantly affected by treatments in 2016B, while the number of pods was impacted in 2017A. Pestwin, a botanical insecticide blend (containing Azadirachtin indica, Pongamia pinnata, and Ricinus communis extracts) demonstrated superior efficacy against cowpea aphids. Moreover, it positively influenced plant height, number of pods, and pod biomass, surpassing many chemical insecticides. Pestwin’s environmental friendliness positions it as a potential contributor to reducing environmental pollution, making it a promising candidate for inclusion in IPM programs. Overall, the study underscores the importance of exploring botanical alternatives to chemical insecticides for sustainable pest management in cowpea cultivation.

Detection of oxidative stress and DNA damage in freshwater snail Lymnea leuteola exposed to profenofos

Extensive production and use of organophosphate pesticide in agriculture,has risen concerned about its ecotoxicity and risk assessment of insecticides,which are more important.Therefore,the present investigation was aimed to study the induction of oxidative stress and DNA damage by organophosphate insecticide profenofos(PFF)in freshwater snail Lymnea luteola(L.luteola).The median lethal value(96 h LC50)of PFF was estimated as 1.26 mg/L for L.luteola in a semi-static system and on the basis of LC50 value three concentrations viz.,0.126(1/10 of LC50,Sublethal I),0.63(1/2 of LC50,Sublethal II)and 0.84 mg/L(2/3 of LC50,Sublethal III)were determined.Snails were exposed to above-mentioned concentrations of PFF along with solvent control(acetone)and negative control for 96 h.The haemolymph was collected at 24 and 96 h of after treatment.In heamolymph of PFF exposed snail,lipid peroxide,glutathione reduced glutathione S transferase and superoxide dismutase activities at the tested concentrations significantly differ from those in the control.The genotoxicity induced in hemocytes of treated snails was measured by alkaline single cell gel electrophoresis assay.The data of this experiment demonstrated significantly enhancement of oxidative stress and DNA damage in the treated snails as compared to controls.Also,we observed statistically significant correlations of ROS with DNA damage(%tail DNA)(R^(2)=0.9708)for 24 h and DNA damage(R^(2)=0.9665)for 96 h.Results of the current experiment can be useful in risk evaluation of PFF among aquatic organisms.The study confirmed the use of comet assay for in vivo laboratory experiments using freshwater snail for selecting the toxic potential of industrial chemicals and environmental contaminants.

Fluorescent Aptamer-Polyethylene Glycol Functionalized Graphene Oxide Biosensor for Profenofos Detection in Food

A biosensor based on self-assembled ssDNA(aptamer)and polyethylene glycol functionalized graphene oxide(GO-PEG)has been designed for sensing profenofos in food.The sensor has employed the fluorescence"on/off"switching strategy in a single step iii homogeneous solution.Compared to traditional detection methods,the strategy proposed here is simple,convenient,fast and sensitive.Furthermore,compared with the general aptamer-GO structure,this aptamer-GO-PEG stmcture is in possession of a better detection performance,wliich is largely attributed to the improvement of the biocompatibility and the adjustment of the adsorption capacity of GO by grafting the blocking agent PEG onto the surface of GO.Additionally,the improved biocompatibility of GO shows better stability in salt solutions and physiological solutions,which is more conducive to its practical application in foods.In this project,profenofos had been detected with the proposed strategy,and the limit of detection has been controlled to be 0.21 ng/mL.This aptasensing assay has been applied to detemiining profenofos in(spiked)tap water,cabbage and milk with the recovery values ranging from 93.1% to 108.5%,from 90.8% to 113.2% and from 105.9% to 114.2%,respectively.