Inhibition of inflammatory cytokine production and protection against endotoxin toxicity by benzydamine

The present study was designed to assess the effect of N,N-dimethyl-3-[(1-benzyl-1H-indazol-3-yl)ossi]-1-propanamine (benzydamine) on in vivo and in vitro production of inflammatory cytokines. Benzydamine inhibited tumour necrosis factor-alpha (TNF-α) production in vitro by human lipopolysaccharide-stimulated monocytes with an ED₅₀ of ~25 μM (12 donors). Under the same conditions, benzydamine had modest or no effect on production of interleukin (IL-1), IL-6 and IL-8. Inhibition of TNF-α production was not restricted to LPS in that similar results were obtained using inactivated streptococci. Inhibition of TNF production was associated with a modest (about 30% at 50 μM, 7 donors) reduction of mRNA. A similar inhibition of TNF-α production was also detected with mouse peritoneal macrophages. With mouse cells benzydamine also substantially inhibited IL-1 production in vitro. In vivo treatment with benzydamine (40 mg/kg s.c.) protected mice against LPS lethality. Protection against septic shock was observed when benzydamine was administered before or concomitantly with LPS. Protection against LPS toxicity was associated with a marked reduction of serum levels of TNF-α and IL-1β, whereas IL-6 was unaffected. Inhibition of inflammatory cytokine production may play a role in the anti-inflammatory activity of benzydamine and provide suggestions for novel therapeutic applications.