L-Canavanine sulfate is a selective inducible NO synthase inhibitor.

L-Canavanine sulfate,which is hardly toxic alone, potentiated the cytotoxicity of VIN and PTX in HeLa and hepatocellular carcinoma cells[1].

Intravenous infusion of L-canavanine (100 mg/kg), a selective inhibitor of inducible NO synthase in vitro, 60 min and 180 min after lipopolysaccharide challenge, produced an increase in mean arterial pressure and reversed the lipopolysaccharide induced hypotension. However, in lipopolysaccharide challenged animals protected from hypotension by administration of L-canavanine (60 min post challenge), intravenous infusion of NG-nitro-L-arginine methyl ester at 180 min post challenge caused an immediate rise in mean arterial pressure, followed by a rapid fall in blood pressure and heart rate, and sudden death. In contrast, a second dose of L-canavanine at 180 min post challenge maintained blood pressure for the duration of the experiment. Inhibition of both constitutive and inducible NO synthase during endotoxaemia is lethal[2].

The following cancer cells grown in arginine-rich and arginine-free media were employed: HeLa, Hep G2 and SK-HEP-1. Drug combination experiment used a method based on the median-effect principle and mass-action law[1].