Fipronil (F) a pesticide considered of second generation cause various toxic effects in target and non-target organisms including humans in which provoke neurotoxicity, having the antagonism of gamma-amino butyric acid (GABA) as their main mechanism for toxic action. GABAergic system has been involved in processes related to the memory formation and consolidation. The present work studied the importance of GABA to the mechanisms involved in the very early development of fipronil-induced memory impairment in rats. Memory behavior was assessed using new object recognition task (ORT) and eight radial arm maze task (8-RAM) to study effects on cognitive and spatial memory. Locomotor behavior was assessed using open field task (OF). The dose of fipronil utilized was studied through a pilot experiment. The GABA antagonist picrotoxin (P) was used to enhance fipronil effects on GABAergic system. Fipronil or picrotoxin decrease memory studied in ORT and 8-RAM tasks. Additionally, F and P co-exposure enhanced effects on memory compared to controls, F, and P, suggesting strongly a GABAergic effect. Weight gain modulation and fipronil in blood were utilized as animal's intoxication indicators. In conclusion, here we report that second-generation pesticides, such as fipronil, can have toxic interactions with the CNS of mammals and lead to memory impairment by modulating the GABAergic system.

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Recent reports show that fipronil affects non-target organisms, including environmental species populations and potentially humans. We aimed to examine if fipronil exposure affects the systolic blood pressure and related biomarkers. Thus, fipronil was orally administered to rats (30 mg/kg/day) during 15 days (Fipronil group) or physiological solution (Control group). While fipronil increased significantly the systolic blood pressure (158±13 mmHg), no significant changes were observed in Control group (127±3 mmHg). Significantly, higher levels of fipronil in plasma were observed in Fipronil group (0.46±0.09 μg/mL versus 0.17±0.11 μg/mL in Control group). Fipronil group showed lower weight gain compared with Control group. While fipronil resulted in higher concentrations of endothelin-1, reduced antioxidant capacity and lower levels of circulating matrix metalloproteinase 2 (MMP-2) and nitric oxide (NO) metabolites compared to Control group, no alteration was observed in serum biomarkers of renal and hepatic/biliary functional abilities. Therefore, this study suggests that fipronil causes hypertension and endothelin-1 plays a key role. Also, these findings suggest that reductions of both MMP-2 and NO may contribute with the elevation of systolic blood pressure observed with fipronil.

Objective To assess and compare circulating tissue inhibitor of metalloproteinase 3 (TIMP‐3) concentrations between women with pre‐eclampsia and healthy pregnant women. We also aimed to determine the relationships between circulating TIMP‐3 and matrix metalloproteinase 2 (MMP‐2), MMP‐9, TIMP‐1, and TIMP‐2 concentrations in pre‐eclampsia. Methods A primary case–control study included patients with pre‐eclampsia (n = 219) and gestational hypertension (n = 118), healthy pregnant women (n = 214), and non‐pregnant women (n = 66), and a replication case–control study included patients with pre‐eclampsia (n = 177) and healthy pregnant women (n = 124), all from southeastern Brazil. Plasma TIMP‐3, MMP‐2, MMP‐9, TIMP‐1, and TIMP‐2 concentrations were assessed using commercially available enzyme‐linked immunosorbent assay kits, and the relationships between them were analyzed using Spearman's correlation. Results In our primary study, patients with pre‐eclampsia and gestational hypertension exhibited increased TIMP‐3 concentrations compared with healthy pregnant women (both P < 0.0001) and non‐pregnant women (both P < 0.001). These findings were confirmed in the replication study, showing elevated TIMP‐3 concentrations in women with pre‐eclampsia versus healthy pregnant women (P < 0.001). We found no difference in TIMP‐3 concentrations between early‐onset and late‐onset pre‐eclampsia. Moreover, TIMP‐3 concentrations were significantly correlated with plasma concentrations of TIMP‐1 (r = 0.2333; P = 0.0086) and MMP‐2 (r = 0.2159; P = 0.0156) in pre‐eclampsia. Conclusions Circulating TIMP‐3 concentration is increased in women with pre‐eclampsia compared with healthy pregnant women, and it is positively correlated with plasma MMP‐2 and TIMP‐1 concentrations in pre‐eclampsia.