Rubimetide (Met-Arg-Trp) derived from Rubisco exhibits anxiolytic-like activity via the DP1 receptor in male ddY mice

In this study, we found that Met-Arg-Trp (rubimetide), which had been isolated as a hypotensive peptide from a pepsin–pancreatin digest of spinach ribulose bisphosphate carboxylase/oxygenase (Rubisco), has anxiolytic-like activity in the elevated plus-maze test at a dose of 0.1 mg/kg (i.p.) or 1.0 mg/kg (p.o.) in mice with p < 0.01 and p < 0.05, respectively. The anxiolytic-like activity of rubimetide (0.1 mg/kg, i.p.) was blocked by BW A868C (60 μg/kg, i.p.), an antagonist for the DP1 receptor, suggesting the anxiolytic-like activity of rubimetide is mediated by prostaglandin D2 and the DP1 receptor.