[In vitro Modulating Activity of aqueous extracts from American Plants on Chlorpyrifos-induced toxicity on Murine Splenocytes].

Background: Chlorpyrifos is an highly toxic pesticide, which can induce immunotoxicity with deleterious effects on health worldwide. On the other hand, American plants can provide derivatives with protective and immunostimulating activity. Thus, plant potential against chlorpyrifos should be assayed.

Objective: To identify bioactive aqueous extracts from Lantana grisebachii (LG), Aspidosperma quebracho-blanco (AQ), Peumus boldus (PB), and Ilex paraguariensis (IP), against chlorpyrifos-induced toxicity on female Balb/c splenocytes. Material and method: Splenocytes were treated in vitro for 72 hours with 0-35 µg/mL of chlorpyrifos, 0-100 µg/mL of each extract (LG, AQ, PB, IP), and 0-5 µg/mL of concanavalin A. Then, cellular viability and death (resazurin-based and propidium iodide stainings), hydroperoxides, lipoperoxides (xylenol orange-based assay), ?-glutamyl transpeptidase activity (Szasz method) were measured and analyzed statistically.

Results: Chlorpyrifos reduced splenocyte viability in a dose-dependent manner, which was counteracted by AQ and IP, which was less active in concanavalin A-responsive cells (p<0.05). Chlorpyrifos toxicity involved ?-glutamyltranspeptidase induction with a consequent peroxide reduction, whereas AQ and mainly IP antagonized these responses (p<0.05).

Conclusions: The extracts of Ilex paraguariensis and Aspidosperma quebracho-blanco protected splenocytes in vitro against chlorpyrifos. This effect depended on cellular type, given that concanavalin A-responsive cells were more susceptible to this toxic.