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Insecticides
Published in Frank A. Barile, Barile’s Clinical Toxicology, 2019
The pyrethroid insecticides are derived from the naturally occurring compound pyrethrum, from the dried flower heads of the yellow flower Chrysanthemum cineriaefolium.* The synthetic acid-alcoholic esters are categorized into several classes of the active ingredients; namely, pyrethrins types I and II.† Pyrethrum flowers have been used as insecticides for centuries, particularly by Caucasian tribesmen and Armenians. The powdered form was introduced into the United States in 1855, after which its importation expanded tremendously. Type I pyrethrins include allethrine, permethrin, and cismethrin; type II pyrethrins include fenvalerate, deltamethrin, and cypermethrin. The compounds (0.17–0.33%) are combined with piperonyl butoxide or n-octyl-dicycloheptane dicarboximide (2–4%) in therapeutic nonprescription pediculocide preparations for the treatment of lice, tick, and mite infestation.‡ Pyrethrins are noted for their quick “knock-down” effect on flying insects, particularly flies and mosquitoes. The products are available in lotions, sprays, and shampoos for skin or scalp applications as well as for removal from furniture and bedding material.
Pesticides and Chronic Diseases
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
Some commercial pyrethroids are found in the following: allethrin (Pynamin), bifenthrin, bioresmethrin, cypermethrin (Ripcord), decamethrin, fenothrin, fenpropanate, fenvalerate (Belmark, Pydrin), permethrin (Ambush, Ectiban, Pounce), phthalthrin or tetramethrin (Neo-Pynamin), and resmethrin (Synthrin, Chrysron).
Restraint stress induces uterine microenvironment disorder in mice during early pregnancy through the β2-AR/cAMP/PKA pathway
Published in Stress, 2021
Jiayin Lu, Guanhui Liu, Zixu Wang, Jing Cao, Yaoxing Chen, Yulan Dong
In our previous study, restraint stress was shown to cause local immune regulation disorder in the uterus (Liu, et al., 2014). Additionally, a study showed that CD4+ T cells mediate oxidative stress to cause hypertension during preeclampsia (Wallace et al., 2014). In our study, the protein levels of p-NF-κB p65 were increased under restraint stress during early pregnancy on E3, E5 and E7 (Figure 6(D)). p-NF-κB p65 may promote inflammation, which is consistent with our previous studies. The release of TNF-α (tumor necrosis factor-alpha) is affected by increases of NF-κB and results in endothelial cell dysfunction, leading to preeclampsia (Kim et al., 2017). In addition, a study showed that fenvalerate activates the ERK/NF-κB pathway, inducing apoptosis in the liver (Qiu et al., 2019). Thus, we speculated that ERK1/2 may be involved in restraint stress. In our study, the protein levels of ERK1/2 were detected. The results showed that the protein expression of ERK1/2 was increased significantly under restraint stress during early pregnancy (Figure 6(C)). ERK1/2 participates in depression in offspring caused by prenatal stress (Guan et al., 2013). In summary, uterine development may be affected by ERK1/2/NF-κB under restraint stress during early pregnancy (Figure 9).
Effect of deltamethrin and fluoride co-exposure on the brain antioxidant status and cholinesterase activity in Wistar rats
Published in Drug and Chemical Toxicology, 2018
Adil Mehraj Khan, Rajinder Raina, Nitin Dubey, Pawan Kumar Verma
Overwhelming pro-oxidant processes produce oxidative stress which is prevented by both enzymatic and non-enzymatic components of the body’s antioxidant system. Glutathione S-transferases catalyze the conjugation of reduced glutathione (GSH), via the reaction of sulfydryl group to electrophilic centers of a wide range of substrates. The induction of GST activity has been reported by El-Banna et al. (2008) in fenvalerate-treated rats and Shivarajashankara et al. (2001) in F− treated rats. The induction of GST in the deltamethrin exposed rats could be a defensive mechanism to counter-balance the oxidative insult (Dubey et al.2012). F− has an inhibitory effect on several enzymes (Birkner et al.2006, Dubey et al.2013). Thus in F− exposed groups there is both induction of GST, in response to toxic stress, as well as, inhibition of this enzyme with F− that could account for the non-significant difference, of GST in these groups, when comparing to control group.
Pyrethroid epidemiology: a quality-based review
Published in Critical Reviews in Toxicology, 2018
Carol J. Burns, Timothy P. Pastoor
The collective evidence for male hormonal and reproductive effects was methodologically very weak. There were 15 publications (13 studies) that addressed sperm quality and/or a disruption in sperm genetic integrity (Table 2(A)). Most relied upon a single semen sample (n = 10), a spot urine sample (n = 9) that was within the range of the general population (n = 6) and all were a cross sectional design. The exposure metric was considered strong for three investigations that were among the few occupational settings. These focused on a single pyrethroid and evaluated air and dermal samples to confirm fenvalerate exposure to a group of factory workers in China (Bian et al. 2004; Xia et al. 2004; Lifeng et al. 2006).