scholarly journals Esterase, Glutathione S-Transferase and NADPH-Cytochrome P450 Reductase Activity Evaluation in Cacopsylla pyri L. (Hemiptera: Psyllidae) Individual Adults

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 329
Author(s):  
Dolors Bosch-Serra ◽  
Marcela A. Rodríguez ◽  
Jesús Avilla ◽  
María José Sarasúa ◽  
Xavier Miarnau
Keyword(s):  
Cytochrome P450 ◽  
Insecticide Resistance ◽  
Reductase Activity ◽  
Cytochrome P450 Reductase ◽  
Glutathione S Transferase ◽  
Factors Affecting ◽  
Cacopsylla Pyri ◽  
Nadph Cytochrome ◽  
P450 Reductase ◽  
Nadph Cytochrome P450 Reductase

Cacopsylla pyri (L.) (Hemiptera: Psyllidae) is a key pest of pear orchards in Spain. The large number of insecticide treatments necessary for control may be an important contributor to the emergence of resistance. Laboratory toxicity and biochemical assays are necessary to validate the existence of insecticide resistance and establish the underlying mechanisms. All the methodologies developed to evaluate enzyme activity in C. pyri to date have incorporated “pools” of adults to detect minimum activity ranges. In this study, we determined the optimal working conditions for evaluation of the activities of esterase, glutathione S-transferase and NADPH-cytochrome P450 reductase in individual insects via colorimetric methods using a microplate reader. The main factors affecting enzymatic analysis activity, such as enzyme source and substrate concentration, filter wavelength, buffer pH, reaction time and additives, were evaluated for optimization. Determining the frequency of resistant individuals within a population could be used as an indicator for the evolution of insecticide resistance over time. Two laboratory strains, one of them selected with cypermethrin, and two field populations were analyzed for this purpose. The data obtained revealed high values and great variation in the activity ranges of esterase (EST) in the insecticide-selected population as well as in the field populations validating the applied methodology.

scholarly journals Influence of acetaminophen and trichloroethylene on liver cytochrome P450-dependent monooxygenase system.

2000 ◽  
Vol 47 (4) ◽  
pp. 1129-1136 ◽  
Author(s):  
A Plewka ◽  
B Zielińska-Psuja ◽  
J Kowalówka-Zawieja ◽  
G Nowaczyk-Dura ◽  
D Plewka ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Reductase Activity ◽  
Monooxygenase System ◽  
Cytochrome P450 Reductase ◽  
Control Value ◽  
Liver Cytochrome ◽  
Nadph Cytochrome ◽  
P450 Reductase ◽  
Cytochrome P450 Content ◽  
Nadph Cytochrome P450 Reductase

The aim of the study was to evaluate the effect of acetaminophen (APAP) and/or trichloroethylene (TRI) on the liver cytochrome P450-dependent monooxygenase system, CYP2E1 and CYP1A2 (two important P450 isoforms), and liver glutathione (GSH) content in rats. Rats were given three different doses of APAP (250, 500 and 1000 mg/kg b...) and then the above-mentioned parameters were measured for 48 h. The lowest APAP dose produced small changes in the cytochrome P450 content of liver. At 500 mg/kg APAP increased the cytochrome P450 content to 230% of the control. The inductive effect was seen at 1000 mg/kg dose but at 24 h and later. NADPH-cytochrome P450 reductase activity was the highest after the lowest dose of APAP, while after the highest dose it was equal to the control value. TRI increased both the cytochrome P450 content and the NADPH-cytochrome P450 reductase activity. When TRI was combined with APAP, both these parameters increased in the first hours of observation, but they returned to the control values at 24 h. When APAP was given at 250 mg/kg, GSH levels decreased to 55% of the control at 8 h and returned to the control values at 24 h. The higher doses of APAP decreased GSH levels more than the lowest dose, but after 24 h GSH levels did not differ from those of the control. When TRI was given at 250 mg/kg, the GSH levels decreased to 68% of the control at 2 h and then they increased gradually and tended to exceed the control values at 48 h. The effect of TRI combined with APAP on the level of GSH was virtually the same as that of APAP alone given at 500 mg/kg.

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