Effects of type II pyrethroid cyhalothrin on rat innate immunity: A flow cytometric study

Effect of cyhalothrin on Ehrlich tumor growth and macrophage activity in mice

“…Increased phagocytosis and respiratory burst rates with the consequent generation and release of reactive oxygen intermediates such as H 2 O 2 , characterize macrophage activation (35). In this respect, the present results on Ehrlich tumor-activated macrophage phagocytosis in mice agree with and support those previously reported by our laboratory for onco BCGactivated peritoneal macrophages in rats (15). Contrary to our previous data, no differences were found here in the effects of cyhalothrin on percent macrophage phagocytosis (number of macrophages presenting phagocytosis).…”

“…A 3.0-mg/kg dose of cyhalothrin present in the Grenade formulation was prepared in distilled water (3.0 mg/mL) and administered to the mice by gavage, once daily for 7 days. This formulation dose was chosen based on our previous studies suggesting that it produced no overt clinical signs or symptoms of intoxication but induced stress-like symptoms in rats (11), decreased macrophage and neutrophil activities (14,15) and increased c-fos immunoreactivity in the paraventricular nucleus of the rat hypothalamus (16). The LD 50 calculated for mice of cyhalothrin present in this formulation was reported to be 37-62 mg/kg (22).…”

“…Thus, cyhalothrin (3.0 mg·kg -1 ·day -1 for 7 days) induced no overt signs or symptoms of intoxication in rats, but did produce behavioral effects in the open field and plus-maze apparatuses similar to those induced by anxiogenic-like drugs such as picrotoxin (11). Further analysis of the effects of cyhalothrin showed that this pesticide increased serum corticosterone levels (11), decreased peritoneal macrophage activity in rats (14,15), and increased c-fos immunoreactivity in the paraventricular nucleus of the hypothalamus, but not in the basolateral amygdala of rats (16). Ehrlich tumor cells have been reported to elicit a strong host immune response (17,18), a fact that, together with other properties, makes this tumor an interesting model for analysis of the effects of drugs or external environmental agents on tumor growth.…”

Evaluation of the Immunotoxic Effects of Sub-Chronic Doses of Lambda-Cyhalothrin in Murine Model

“…In this respect several in vivo and in vitro studies have been done to evaluate the effect of cyhalothrin and LCT on phagocytic cells. Cyhalothrin decreased oxidative burst, nitric oxide production, the intensity, and percentage of phagocytosis in peritoneal macrophages [11,21,50].…”

“…In this respect several in vivo and in vitro studies have been done to evaluate the effect of cyhalothrin and LCT on phagocytic cells. Cyhalothrin decreased oxidative burst, nitric oxide production, the intensity, and percentage of phagocytosis in peritoneal macrophages [11,21,50].In a dose-dependent way, LCT-induced macrophage cell line RAW 264.7 cytotoxicity, decreased the cells viability and enhanced its apoptosis, through LCT estrogenic activity or its ability to increase reactive oxygen species (ROS) and DNA damage [36,51].Besides the ability of LCT to alter the immune response through its neurological and endocrine responses, different scenarios could also explain the immunological alteration that resulted from the exposure to LCT. One scenario based on the direct genotoxicity of the LCD.…”