Lethal and sublethal effects of a methomyl-based insecticide in <i>Hoplobatrachus rugulosus</i>

Abstract

The aim of this study was to investigate the lethal and sublethal toxicity of a methomyl-based insecticide in Hoplobatrachus rugulosus, as methomyl-based insecticides are applied in massive amounts and agrochemicals have effects on the decline in amphibian populations. To evaluate the toxic effects of methomyl from agricultural application, a methomyl-based insecticide containing 40% methomyl was selected. The median lethal concentration of 96 hours of methomyl exposure was 8.69 ppm for H. rugulosus tadpoles. The lethal concentration also produced severe histological damage in the livers and kidneys of the exposed tadpoles. The sublethal concentration used for methomyl was 144 ppb during the metamorphosis period. It was found that the sublethal concentration of the methomyl compound could decrease growth, metamorphosis time, and size, disturb biochemical parameters, and produce histological damage. In livers, methomyl effects increased oxidative stress and dramatically decreased the glycogen level of the treated froglets. Mononuclear infiltration, blood congestion, amorphous substances, and hepatocytes vacuolization were observed throughout liver tissue. The methomyl-based insecticide also increased oxidative stress and decreased nitric oxide levels in the kidneys of the exposed froglets. Renal tissue damage including blood congestion, amorphous substances, and Bowman’s capsule spaces reduction were found in the methomyl exposure group. The methomyl compound also produced vacuoles in various stages of oocytes, but no histological damage was found in testicular tissue. Our results indicated strong toxic effects of the methomyl-based insecticide on H. rugulosus, a broadly tolerant anuran.

The Antioxidant Role of a Taurine-Enriched Diet in Combating the Immunotoxic and Inflammatory Effects of Pyrethroids and/or Carbamates in Oreochromis niloticus

“…These findings could be attributed to the metabolic changes in protein and carbohydrate metabolism of fish induced by toxic stress, which led to the consumption of energy storage to detoxify the toxicant or repair mechanisms; hence, little energy was available for growth. A reduction in growth has previously been reported for LCT exposed in O. niloticus [ 30 ]; likewise for cypermethrin (a member of pyrethroids family) given to common carp [ 50 ], and MTM given to Hoplobatrachus rugulosus [ 25 ].…”

“…MTM exposures pose a significant health risk and result in toxicity for various aquatic species, including common carp [ 23 , 24 ]. MTM—which is essential in numerous vertebrate biomass ecosystems and substantial as a bioindicator for agrochemical pollution by, for example, insecticides—is extremely toxic to non-target organisms, including amphibians [ 25 ]. This insecticide is highly soluble in water and has low to moderate solubility in soil [ 26 ].…”

Green Tea Attenuates methomyl-Induced Cardiac Toxicity Through Modulating Oxidative Stress and Nuclear Factor kappa B Up- Regulation in Mice

“…It may be the result of reduced production of reactive oxygen species as catechins exhibit the strong property of scavenging reactive oxygen species [29]. Administration of ME increases ROS production and oxidative stress, leading to lipid peroxidation and depletion of antioxidant capacity [30,31]. The results of the present study showed an increase in MDA concentration and decreased activity of the level of SOD and GSH.…”

Evaluation The Effect of The Aqueous Extract of Green Tea on Renal Toxicity Induced by-Methomyl in Experimental Animals Model تقییم تاثر المستخلص المائی للشای الاخضر علی تسمم الکلی المستحدث بواسطه المیثومایل فی حیوانات التجارب

“…It is known that carbamates can stimulate the formation of reactive oxygen species (ROS) and thus alterations in antioxidant enzymes, resulting in oxidative stress (Ott et al .,2007). Lipid peroxidation (LPO) is considered as one of the important molecular mechanisms through which carbamate can induce toxicity (Heikal et al, 2013, Trachantong et al, 2017, Mansour et al, 2019. Methomyl (MET) [S-methyl N-(methyl carbamoyloxy) thioacetimidate; C 5 H 10 N 2 O 2 S] is considered as an oxime carbamate insecticide which found to be highly toxic to all living organisms.…”