Rotundine

Rotundine is an antagonist of dopamine D1, D2 and D3 receptors with IC₅₀s of 166 nM, 1.4 μM and 3.3 μM, respectively. Rotundine is also an antagonist of 5-HT_1A with an IC₅₀ of 370 nM. IC50 & Target:IC50: 166 nM (D1 receptor), 1.4 μM (D2 receptor), 3.3 μM (D3 receptor), 370 nM (5-HT_1A)^[1] In Vivo:Rotundine (l-THP) possesses a blocking effect on dopamine D₁ and D2 receptors. On day 1 and 7, there is no difference in locomotor counts between the Rotundine groups (6.25, 12.5, and 18.75 mg/kg) and saline group. Locomotor counts are greatly increased in the oxycodone group compare with the saline group. Rotundine at doses of 6.25, 12.5, and 18.75 mg/kg antagonizes hyperactivity induced by oxycodone. Rotundine (6.25, 12.5 mg/kg) does not affect the magnitude of sensitization, but there is a marked difference between oxycodone+oxycodone group and Rotundine (18.75 mg/kg)+oxycodone+oxycodone group, indicating that Rotundine (18.75 mg/kg) greatly inhibits the development of oxycodone sensitization^[2].