(S)-(+)-Rolipram ((+)-Rolipram) inhibits human monocyte cyclic AMP-specific PDE4 with an IC50 of 0.75 μM and exhibits anti-inflammatory and anti-depressant activity in the central nervous system, though it is less potent than its R enantiomer.

PDE4:0.75 μM

S-(+)-Rolipram suppresses LPS-induced TNFα expression from human monocyte through inhibiting PDE4 with IC50 about 2 μM. [1] 1 μM S-(+)-Rolipram significantly antagonizes ovalbumin (OA) induced concentration-related contractions of tracheal rings which are isolated from OA-sensitized guinea pigs. [2] S-(+)-Rolipram inhibits PDE4 activity in a CHO-K1 cell line which stably expresses a recombinant full length human PDE-4a with IC50 at 450 nM. [3] Treatment of the human glioma cell line A-172 with Rolipram (including both R- and S-enantiomers of Rolipram) results in increased expression of the cell cycle inhibitors p21 [Cip1] and p27 [Kip1], and decreased activity of cdk2, a cyclindependent kinase essential for cell cycle progression. As a result, the proliferation of A-172 cells is inhibited, with induction of a G1 block. Eventually, Rolipram-treated A-172 cells undergo differentiation, which is followed by apoptotic cell death. [4]

In anesthetized, ventilated OA-sensitive guinea pigs, S-(+)-Rolipram reduces OA-induced bronchoconstriction with ID50 values of approximately 0.25 mg/kg i.v. Histamine- and leukotriene D4-induced bronchoconstriction are not affected by doses of S-(+)-Rolipram which abolishes the response to OA. Higher doses (3-10 mg/kg) reduce histamine-, but not the leukotriene D4-induced bronchoconstriction. In conscious OA-sensitive guinea pigs, intragastric pretreatment with S-(+)-Rolipram dose-dependently reduces both the OA-induced decreases in specific conductance as well as the corresponding pulmonary eosinophil influx as assessed by both bronchoalveolar lavage and histological evaluation. [2]