The effect of piperazine on some biochemical properties of Galleria mellonella L. (Lepidoptera: Pyralidae) hemolymph tissue

Antibacterial and antifungal substances are widely added to artificial diet in order to prevent microbial contamination in insect culture and nutritional physiology studies under laboratory conditions. Recently, some new generation antibacterial, antifungal and anthelmintic substances have been used in insect rearing studies. In this study, the oxidative effect of Piperazine, a clinically important hexahydropyrazine anthelmintic, on Galleria mellonella L. hemolymph tissue by adding artificial diet were investigated. G. mellonella larvae were reared until 7th larval stage in artificial diet containing 0.001g, 0.01g, 0.1g and 1g piperazine per 100g of diet. Using hemolymph collected from 7th instar larvae, the amount of lipid peroxidation final product malondialdehyde (MDA), protein oxidation product protein carbonyl (PCO), and detoxification enzyme glutathione S-transferase (GST) activity were measured. According to the results obtained, when the piperazine concentrations tested with the control group were compared, statistically significant differences were found in the amount of MDA, PCO and GST activity in the hemolymph of the insect. While the amount of MDA was 0.01 ± 0.0021 nmol/mg protein in the control group, this amount increased approximately two-fold at the highest concentration (0.0231 ± 0.0050 nmol/mg protein). PCO amount was measured as 104.46 ± 18.95 nmol/mg protein in the control group. PCO amount increased to 179.97 ± 22.42 nmol/mg protein at the concentration of 0.1g piperazine. On the other hand, when the control group (142.63 ± 28 µmol/mg protein/min) and the highest piperazine concentration (261.16 ± 45 µmol/mg protein/min) were compared in the GST activity, it was determined that there was a statistically significant increase. This study showed that the tested piperazine concentrations caused significant changes in the detoxification capacity and oxidative stress markers in the insect's hemolymph tissue.