Origanum majorana essential oil improves the rat's sexual behavior and testicular oxidative damage induced by imidacloprid via modulating the steroidogenesis pathways.

The neonicotinoid insecticide imidacloprid has been linked to significant reproductive damage in mammals. Origanum majorana essential oil (OME) is a natural herbal product used in the management of many diseases due to its strong antioxidant effects. The oil was hydrodistilled from O. Majorana and analyzed using GC/MS then its possible protective mechanisms against IMI-induced reprotoxicity in male rats were investigated. 28-adult male Wistar rats were divided into 4 groups as follows: group (1) control group, group (2) OME, group (3) IMI, and group (4) IMI + OME. The treatments were applied daily via oral gavage for 60 days. Remarkable abnormalities in both territorial aggressive and sexual behaviors were observed in IMI-treated rats with a significant elevation of serum FSH and LH as well as altered testicular redox status. Along with inhibition of the testicular expression of StAR and aromatase genes and serum total testosterone in addition to abnormal sperm count, viability, motility, and morphology. Histopathological examination showed severe degeneration and necrosis in both germ cells and Leydig cells with atrophy in most of the seminiferous tubules. Co-administration of OME with IMI notably improved all the above-mentioned studied parameters, and restored rats' spermatogenesis, sexual behavior, and favorably modulates the levels of both testosterone and gonadotropic hormones via its potent antioxidant effect. These findings support the use of OME as a fertility enhancer and suggest that it could be used to manage pesticide-induced male infertility.

A comprehensive review on the pretreatment and detection methods of neonicotinoid insecticides in food and environmental samples.

In recent years, the residues of neonicotinoid insecticide in food and environmental samples have attracted extensive attention. Neonicotinoids have many adverse effects on human health, such as cancer, chronic disease, birth defects, and infertility. They have substantial toxicity to some non-target organisms (especially bees). Hence, monitoring the residues of neonicotinoid insecticides in foodstuffs is necessary to guarantee public health and ecological stability. This review aims to summarize and assess the metabolic features, residue status, sample pretreatment methods (solid-phase extraction (SPE), Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), and some novel pretreatment methods), and detection methods (instrument detection, immunoassay, and some innovative detection methods) for neonicotinoid insecticide residues in food and environmental samples. This review provides detailed references and discussion for the analysis of neonicotinoid insecticide residues, which can effectively promote the establishment of innovative detection methods for neonicotinoid insecticide residues.

Imidacloprid exposure cause the histopathological changes, activation of TNF-α, iNOS, 8-OHdG biomarkers, and alteration of caspase 3, iNOS, CYP1A, MT1 gene expression levels in common carp (Cyprinus carpio L.).

Imidacloprid (IMI) is a neonicotinoid that is widely used for the protection of crops and carnivores from insects and parasites, respectively. It is well known that imidacloprid exposure has a harmful effect on several organisms. However, there is little information about imidacloprid toxicity in aquatic animals, particularly fish. Thus, in the current study, we assessed the histopathological changes; activation of iNOS, 8-OHdG and TNF-α; and expression levels of caspase 3, iNOS, CYP1A and MT1 genes in the common carp exposed to imidacloprid. For this purpose, fish were exposed to either a low dose (140 mg/L) or a high dose (280 mg/L) of imidacloprid for 24 h, 48 h, 72 h and 96 h. After IMI exposure, we detected hyperplasia of secondary lamellar cells and mucous cell hyperplasia in the gills, as well as hydropic degeneration in hepatocytes and necrosis in the liver. Moreover, 8-OHdG, iNOS and TNF-α activation was found particularly in the gills and liver but also moderately in the brain. Transcriptional analysis showed that caspase 3 expression was altered low dose and high doses of IMI for 72 h and 96 h exposure (p < 0.05), iNOS expression was up-regulated with both low and high doses of IMI and in a time-dependent manner (p < 0.05, p < 0.01, p < 0.001), CYP1A expression was not significantly changed regardless of the dose of IMI and exposure time (p > 0.05) except with low and high doses of IMI for 96 h (p < 0.05), and lastly, MT1 gene expression was up-regulated only in the brain with low doses of IMI for 96 h and high doses of IMI for 48 h, 72 h and 96 h exposure (p < 0.05, p < 0.01). Our results indicated that acute IMI exposure moderately induce apoptosis in the brain but caused severe histopathological lesions, inflammation, and oxidative stress in the gills, liver, and brain of the common carp.