Chronic toxicity and carcinogenicity evaluation of fenvalerate in rats

Abstract

Groups of 93 male and 93 female Sprague-Dawley rats were fed diets containing 1, 5, 25, and 250 ppm fenvalerate for up to 2 yr. The control group consisted of 183 males and 183 females. Approximately 10 treatment and 20 control rats/sex . group were killed at intervals of 3, 6, 12, and 18 mo. When body weights, food consumption, hematology, clinical chemistry and organ weights did not reveal a treatment effect, two additional groups of 50 males and 50 female rats were placed on 0 or 1000 ppm fenvalerate diets and maintained for 2 yr. Body weight was decreased and organ/body weight ratios were increased in brain, liver, spleen, kidneys (females), heart (females), and testes (males) in the 1000 ppm group. Mammary and pituitary tumors were commonly observed, along with a variety of other tumors occurring randomly among all control and treatment groups. No statistically significant differences in the number and type of neoplasms were observed except for mammary tumors in females in the main study. These effects were judged not to be toxicologically significant, since mammary tumor incidences did not exceed expected incidences in aged female Sprague-Dawley rats, time to tumor appearance was unchanged, and no shift in percent benign versus malignant tumors occurred. Sarcomas identified in the subcutis and dermis in 5/51 1000-ppm-treated males were also identified in 2% (1/50), 2% (2/102), and 0-6% of concurrent, original, and historical controls, respectively. Microscopic examination did not reveal any treatment-related lesions. The no-observable-effect level was determined to be 250 ppm.

Efectos toxicológicos del uso prolongado e intenso de emisiones de espirales contra mosquitos en ratas y sus implicaciones sobre el control de la malaria

“…The reduction of oxygen stimulates erythropoietin which in turn stimulates the bone marrow to produce RBC. These findings are in agreement with earlier workers (Parker et al 1984, Schoeinig 1995, Shakouri et al 1992, Garba et al 2007a which similarly observed increase in RBC and PCv in rats exposed to pyrethrins however it is contrary to work of Saka et al (2011) which demonstrated no significant increase in haematological parameters (WBC, RBC and PLT) when they exposed rats for one to three daily hours; however, the present study exposed the rats for eight hours daily mimicking daily exposure of man to mosquito coil in normal setting. Since the study further reveals the RBC and PCv levels dropped and became insignificant compared with control at 16 weeks exposure to both transfluthrin and d-allethrin insecticide, it can be concluded that haematological parameters observed do not suggest anemia as a risk factor in mosquito coil exposure.…”

Effects of Sublethal Doses of Fenvalerate (A Synthetic Pyrethroid) Administered Continuously for Four Weeks on the Blood, Liver, and Muscles of a Freshwater Fish, Ctenopharyngodon idella

“…Parker et al (1984) reported increase in hepatic AkP activity in dog exposed to Fenvalerate, which may be due to toxic effect on the liver function. GOT inhibition shows that oxaloacetate and glutamate are not available to Kreb's cycle through this route of transamination but through GPT, which accounts for its increased activity.…”

Protective effect of lycopene on oxidative stress and antioxidant status inCyprinus carpioduring cypermethrin exposure

“…Lipid peroxidation has been shown to increase in plasma and some tissues in CYP and other insecticides toxicities (Parker et al,; Akhtar et al,; Gupta et al,; Aldana et al,). In addition, Üner et al () demonstrated that MDA increased in fish liver and kidney following CYP exposure.…”