Oxidative stress and histopathological changes induced by methylthiophanate, a systemic fungicide, in blood, liver and kidney of adult rats.

BACKGROUND: Methyl-thiophanate (MT), a fungicide largely used in agriculture throughout the world including Tunisia, protects many vegetables, fruits and field crops against a wide spectrum of fungal diseases. Oxidative stress has been proposed as a possible mechanism involved in MT toxicity on non-target organism. METHODS: In the present study, the effect of MT injected intraperitoneally to adult rats at 300 or 500 mg/kg of body weight was studied on blood, liver and kidney. RESULTS: Our results showed 3 days after MT injection, a significant decrease in hemoglobin and hematocrit values. A disruption in total white blood cells and platelets also occurred. Accordingly, an increased in malondialdehyde, H2O2 and advanced oxidation protein levels in liver and kidney were noted with the two doses. A significant change in plasma biomarkers and organ enzymatic and non-enzymatic activities were observed after MT treatment. The modifications in biochemical parameters were substantiated by histopathological data. CONCLUSION: These data confirmed the pro-oxidant effects of this fungicide. Accordingly, care must be taken to avoid mammalian and human exposure to MT.

[Pharmacokinetics and anti-Dicrocoelium activity of thiophanate and its major metabolite in ruminants]. / Pharmacocinétique et activité dicrocoelicide du thiophanate et de son métabolite majeur chez les ruminants.

After a single oral dosage of 40 mg thiophanate/kg in cattle, sheep and goats, the parent compound and its main metabolite: ethyl benzimidazol-1H-yl-2-carbamate (EBC) are evidenced in plasma by HPLC analysis for 60 to 72 hours. The rate of metabolic change of thiophanate into EBC is 34% in sheep, 52% in goats and 57% in cattle. At this dosage, thiophanate seems to be effective against Dicrocoelium in sheep. On the contrary, EBC is uneffective at 15 mg/kg while it seems undetectable in plasma at any time.