Protective effect of anisodamine against Shiga toxin-1: inhibition of cytokine production and increase in the survival of mice.

The purpose of this study was to investigate whether anisodamine could inhibit Shiga toxin-1 (Stx1)-induced cytokine production and increase the survival of Stx1-treated mice. Human monocytic cells were stimulated by Stx1 (1 to 100 ng/mL) with or without anisodamine addition (1 to 400 microg/mL). For in vivo evaluations, C57BL/6 mice were given a single intraperitoneal injection of anisodamine (1 mg) or saline solution after intraperitoneal injection of Stx1 (2.75 microg/kg). The results showed that anisodamine significantly suppressed Stx1-induced tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-8 production. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed that anisodamine suppressed Stx1-mediated TNF-alpha mRNA expression. Further study showed that this TNF-alpha inhibitory effect was via a prostaglandin E2-dependent mechanism. Anisodamine treatment prolonged the survival time of mice and decreased the lethality of Stx1 (94.5% to 44%). Because cytokines, in particular TNF-alpha, contribute to the pathologic process in Stx-producing Escherichia coli (STEC) infection, this study suggested that anisodamine could be a potential drug for treatment of STEC infection.