Oxidative stress, hematological and biochemical alterations in farmers exposed to pesticides.

In this study, a cohort of farmers from the Mateur region in the North of Tunisia, were interviewed and examined for the biochemical effects of pesticides. We studied their haematological profile, lipid parameters, serum markers of nephrotoxicity and hepatotoxicity. We also evaluated the activities of Butyrylcholinesterase (BChE), Acetylcholinesterase (AChE) and thiolactonase-paroxonase (PON). Moreover, lipid peroxidation and activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were determined. The duration of pesticide use and the farmers' age were considered in the analysis. Our results revealed significant differences in some haematological parameters, in liver and kidney functions, in the lipidic status of the pesticide-exposed group. We also reported an increase in the index of incidence of cardiovascular risk in farmer populations. A significant decrease in AChE, BChE and PON levels was found among farmers. Lipid peroxidation, however, increased. The activities of SOD and CAT were remarkably elevated in farmer populations. There was a significant relation between changes in biological markers, the duration of pesticide use and the farmers' age. This study indicates that a long-term exposure to pesticides may play an important role in the development of vascular diseases via metabolic disorders of lipoproteins, lipid peroxidation and oxidative stress, inhibition of BChE and decrease in thiolactonase-PON levels.

Purification of a natural insecticidal substance from Cestrum parqui (Solanaceae).

Cestrum parqui is a shrub originating from Chile used in Tunisia as an ornamental plant. The toxicity of this plant was observed for the first time on the Desert Locust Schistocerca gregaria. It was shown that the toxicity of the plant is concentrated in the Crude Saponic Extract (CSE). In the present research we try to study chemically this fraction to isolate the active substances. The CSE was separated by column chromatography and the obtained fractions were biologically tested on Schistocerca larvae. We observed that only the fraction F9 was active, the separation of this fraction on preparative plates permits to isolate the active compound called S1. The tentative of structure elucidation of the natural substance S1 using 1H and 13C NMR shows that S1 is an heterosidic saponin. Structural modification of S1 structure provoke its activity lose.