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Introduction: Methomyl (MET) is a carbamate insecticide, used in agriculture and public health to eliminate harmful insects. Besides its advantages in agriculture, it causes neurotoxic effects. The aim of this study was to evaluate the effect of MET on Spatial Working Memory (SWM), oxidative stress parameters, and histopathological changes in the hippocampus, as well as the possible protective role of Pelargonium graveolens Essential Oil (EO). Methods: Male Wistar rats were randomized into four groups of six animals: group I as the control that received the vehicle; group II received EO (75 mg/kg b.w), group III received MET (2 mg/kg b.w); and group IV received both MET and EO. The rats were administered the respective doses orally by gavage for 28 days. SWM was assessed using Y-maze on the day before the first treatment and day 28 after the last dose. They were sacrificed by decapitation and their brains were taken for assessing oxidative stress parameters and histopathological analysis. Results: MET treatment caused SWM deficits. Furthermore, drastic changes were observed in aspartate transaminase, alanine aminotransferase, and alkaline phosphatase activities. The level of malondialdehyde significantly increased, whereas antioxidant (glutathione-S-transferase and catalase) enzyme activities significantly decreased. The CA1 region of the hippocampus of rats exposed to MET revealed severe histological alterations. However, supplementation with EO improved SWM and partially restored the activities of antioxidant systems and prevented neuronal cell damage. Conclusion: P. graveolens EO has the potential in mitigating most of the adverse effects in the hippocampus and prevents SWM impairment induced by MET toxicity.

The aim of the present study was to estimate the potential toxic effects of a subacute and a subchronic exposure to methomyl (MET) on some parts of the digestive system in male albino rats. Wistar rats were exposed daily by oral gavage to 4 mg/kg body weight (b.w.) of MET over 28 days in subacute experiments and to 1 mg/kg b.w. of MET for 90 consecutive days in subchronic exposure. Plasma levels of liver function indicators (ALT, AST, ALP and LDH) were significantly elevated after administration of MET to rats. MET had significant pro-oxidative effects on the intestines, as indicated by decreases in nonenzymatic (GSH) and enzymatic antioxidant (GPx, GST and CAT) parameters and significant increases in TBARS levels in both the duodenum and colon of rats. Microscopically, the duodenum and colon of rats exposed to MET showed severe pathological changes. It could be concluded that MET profoundly altered the structure and antioxidant status of intestinal rat tissue, which might lead to intestinal and digestive dysfunctions. [ABSTRACT FROM AUTHOR]

Aspergillus fumigatus is a ubiquitous fungus that grows in decaying organic matter. It can cause disease in both immunodeficient and immunocompetent patients by using virulence factors to escape the host defenses. Some of these factors, such as a diffusate, released from the spores of A. fumigatus, have previously been described. This diffusate was demonstrated to inhibit oxidative burst and phagocytosis of coated red blood cells. The present study has shown that this substance can inhibit the phagocytosis of A. fumigatus spores by murine alveolar macrophages (MALU) and evaluated the action of this substance. We quantified phagocytosis by MALU cells with and without diffusate and evaluated the inhibition of phagocytosis by testing diffusates from different strains. We conclude that the spore diffusate of some strains of A. fumigatus can reversibly decrease the ability of alveolar macrophages to ingest A. fumigatus spores. [Copyright &y& Elsevier]