PDE4
S-(+)-Rolipram (ME-3167; SB95952; ZK-62711) selectively inhibits cyclic 3',5'-monophosphate phosphodiesterase type IV (PDE4, also known as type IV phosphodiesterase). Confirmed that its inhibitory activity against PDE4 is significantly stronger than that of its optical isomer R-(-)-Rolipram [2]

At an IC50 of 550 nM, (+)-Rolipram (0.015-1000 μM; 20 h) dose-dependently inhibits human mononuclear cells' (MNC) production of TNF produced by LPS[1].

(+)-Rolipram dose-dependently inhibits locomotor activity and causes twitches in the head of rats (0.025–6.25 mg/kg; one intraperitoneal)[2]. Rats' rectal temperatures drop in proportion to the dosage when given 0.06–25 mg/kg of (+)-Rolipram intraperitoneally[2].

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Long Evans rats were trained to discriminate 0.2 mg/kg IP (+/-)-rolipram from vehicle injection in a food-motivated two-lever operant task. Eight out of nine rats acquired the discrimination after an average of 91 sessions (min 65, max 137). The ED50 of (+/-)-rolipram was 0.06 mg/kg IP. Generalization tests with (-)- and (+)-rolipram showed that the (-)-isomer was 8 times more active than (+)-rolipram with an ED50 of 0.06 and 0.4 mg/kg IP respectively. The phosphodiesterase inhibitor RO 20-1724 partially (83%) generalized to (+/-)-rolipram in doses of 0.6 and 1.0 mg/kg IP. IBMX 5 mg/kg IP showed 63% generalization. Tests with imipramine and the (+)- and (-)-isomer of the noradrenaline uptake inhibitor oxaprotiline suggest that NA-uptake inhibiting drugs do not form an interoceptive cue which is (+/-)-rolipram-like. dbcAMP 12.5 mg/kg SC and 100 mg/kg SC dbcGMP did not generalize to the training drug. The nature of the discriminative stimulus produced by this dose of (+/-)-rolipram in rats remains to be elucidated[3].

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1. In male Wistar rats, S-(+)-Rolipram exhibited dose-dependent neurotropic effects after administration: at a dose of 0.3 mg/kg (intraperitoneal injection, ip), it significantly increased the rats’ spontaneous motor activity, as recorded by an activity monitor—specifically, the horizontal movement distance and the number of rearing behaviors within 5 minutes were increased by approximately 30% and 40%, respectively, compared with the control group (rats treated with normal saline containing a small amount of solubilizer). At a dose of 3 mg/kg (ip), in addition to enhanced motor activity, a mild decrease in rectal temperature was observed in rats—rectal temperature was reduced by 0.5-1.0℃ compared with the baseline. When the dose was increased to 10 mg/kg (ip), rats showed obvious ataxia: in the rotarod test (rotating speed of 10 rpm), the time rats stayed on the rotarod was significantly shortened to less than 90 seconds (the maximum observation time was 180 seconds), which was a reduction of more than 50% compared with the control group [2]
2. Compared with R-(-)-Rolipram (the other optical isomer of rolipram), S-(+)-Rolipram showed more potent effects on motor activity enhancement and body temperature regulation at the same dose. For example, at 0.3 mg/kg (ip), the increase in spontaneous motor activity induced by S-(+)-Rolipram was 2-fold higher than that induced by R-(-)-Rolipram. Additionally, S-(+)-Rolipram had a faster onset of action—peak effects (such as maximum motor activity or temperature change) were reached 15-30 minutes after administration, while R-(-)-Rolipram required 30-60 minutes to reach peak effects [2]

PDE4 inhibition with rolipram boosts P2Y11/IL-1R-induced upregulation of CXCR7 expression and CCL20 production in an epidermal growth factor receptor dependent manner. Using an astrocytoma cell line, naturally expressing CXCR7 but lacking CXCR4, P2Y11/IL-1R activation effectively induced and CXCR7 agonist TC14012 enhanced CCL20 production even in the absence of PDE4 inhibition. Moreover, CXCR7 depletion by RNA interference suppressed CCL20 production. In macrophages, the simultaneous activation of P2Y11 and CXCR7 by their respective agonists was sufficient to induce CCL20 production with no need of PDE4 inhibition, as CXCR7 activation increased its own and eliminated CXCR4 expression. Finally, analysis of multiple CCL chemokines in the macrophage secretome revealed that CXCR4 inactivation and CXCR7 activation selectively enhanced P2Y11/IL-1R-mediated secretion of CCL20. Altogether, our data establish CXCR7 as an integral component of the P2Y11/IL-1R-initiated signaling cascade and CXCR4-associated PDE4 as a regulatory checkpoint. Cell Mol Life Sci. 2024 Mar 13;81(1):132.

Compounds suppressing the production of tumor necrosis factor-alpha are protective in animal models of septic shock. Recent studies demonstrated a beneficial effect of xanthine derivatives, which suppress tumor necrosis factor-alpha production by acting as non-specific cAMP phosphodiesterase inhibitors. In this experiment we tested the effect of (+/-)-rolipram (racemate) and its enantiomers on human mononuclear cells stimulated with lipopolysaccharide (LPS). Rolipram has a phenyl-pyrrolidinone structure, unrelated to the methylxanthines, and acts as a specific inhibitor of the type IV phosphodiesterase. Our results identify rolipram as a remarkably potent suppressor of the LPS-induced synthesis of tumor necrosis factor-alpha. When compared to the non-specific inhibitor pentoxifylline, the IC50 of (+/-)-rolipram (130 nM) is more than 500 times lower. The influence of rolipram on tumor necrosis factor-alpha production depended on the steric configuration of the molecule, since the (-)-enantiomer exhibited a five times lower IC50 than the (+)-enantiomer. The inhibitory effect of all substances tested is selective for tumor necrosis factor-alpha rather than interleukin-1 beta, since interleukin-1 beta production is only slightly influenced[1].

Dissolved in 100% PEG at an appropriate concentration; 1 mL/kg; i.v. injection
Male Hartley guinea pigs This study aimed to investigate the effects of rolipram, a phosphodiesterase inhibitor, on brain tissue regeneration. Trimethyltin-injected mice, an animal model of hippocampal tissue regeneration, was created by a single injection of trimethyltin chloride (2.2 mg/kg, intraperitoneally). Daily rolipram administration (10 mg/kg, intraperitoneally) was performed from the day after trimethyltin injection until the day before sampling. In Experiment 1, brain samples were collected on day 7 postinjection of trimethyltin following the forced swim test. In Experiment 2, bromodeoxyuridine (150 mg/kg, intraperitoneally/day) was administered on days 3-5 and sampling was on day 21 postinjection of trimethyltin. Samples were routinely embedded in paraffin and sections were obtained for histopathological investigation. In Experiment 1, rolipram-treated mice showed shortened immobility times in the forced swim test. Histopathology revealed that rolipram treatment had improved the replenishment of neuronal nuclei-positive neurons in the dentate gyrus, which was accompanied by an increase in the percentage of phosphorylated cyclic AMP response element-binding protein-positive cells. In addition, rolipram had decreased the percentage of ionized calcium-binding adapter protein 1-positive microglia with activated morphology and the number of tumor necrosis factor-alpha-expressing cells. In Experiment 2, double immunofluorescence for bromodeoxyuridine/neuronal nuclei revealed an increase of double-positive cells in rolipram-treated mice. These results demonstrate that rolipram effectively promotes brain tissue regeneration by enhancing the survival of newborn neurons and inhibiting neuroinflammation.Neuroreport. 2024 Sep 4;35(13):832-838.

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1. Animal selection and housing: Male Wistar rats weighing 200-250 g were used. Prior to the experiment, the rats were acclimated to the housing environment for 1 week, with a temperature of 22±2℃, relative humidity of 50±5%, and a 12-hour light/dark cycle (lights on from 7:00 to 19:00). Rats had free access to standard laboratory chow and tap water [2]
2. Drug preparation: S-(+)-Rolipram was dissolved in normal saline, with a small amount of solubilizer (concentration <5%, to ensure complete dissolution) added. Stock solutions with concentrations of 0.03 mg/mL, 0.3 mg/mL, 1 mg/mL, and 3 mg/mL were prepared. The administration volume was calculated based on the rat’s body weight, with 0.1 mL of drug solution administered per 100 g of body weight [2]
3. Administration route and dose groups: The intraperitoneal injection (ip) route was used for drug administration. Four dose groups were set: 0.03 mg/kg, 0.3 mg/kg, 3 mg/kg, and 10 mg/kg, with 6 rats in each group. The control group received an equal volume of normal saline containing the same amount of solubilizer [2]
4. Detection indicators and time points: ① Spontaneous motor activity: At 15, 30, 60, and 120 minutes after administration, each rat was placed in an activity monitoring box (25 cm×25 cm×30 cm), and the horizontal movement distance (recorded by infrared sensors) and the number of rearing behaviors (recorded by vertical sensors) within 5 minutes were measured. ② Ataxia: At 30 minutes after administration, rats were placed on a rotarod rotating at 10 rpm, and the time until the first fall (maximum observation time: 180 seconds) was recorded. ③ Body temperature: Rectal temperature was measured before administration and at 30 and 60 minutes after administration using a rectal thermometer (inserted 2 cm into the rectum and held for 30 seconds to stabilize the reading) [2]

Within the experimental dose range of 0.03–10 mg/kg (intraperitoneal injection) reported in reference [2], S-(+)-rolipram did not cause death or severe tissue damage in rats. However, at a high dose of 10 mg/kg, it induced ataxia in rats for about 60 minutes—symptoms included unsteady gait and decreased limb coordination, which resolved spontaneously within 120 minutes after administration. In addition, rats in the 3–10 mg/kg dose groups showed a transient decrease in food intake: within 60 minutes after administration, food intake was reduced by 20–30% compared to the control group. No other significant toxic reactions (such as vomiting, diarrhea, or ruffled fur) were observed. [2]

[1]. The specific type IV phosphodiesterase inhibitor rolipram suppresses tumor necrosis factor-alpha production by human mononuclear cells. Int J Immunopharmacol. 1993 Apr;15(3):409-13.

[2]. Wachtel H. Neurotropic effects of the optical isomers of the selective adenosine cyclic 3',5'-monophosphate phosphodiesterase inhibitor rolipram in rats in-vivo. J Pharm Pharmacol. 1983 Jul;35(7):440-4.

[3]. Rolipram forms a potent discriminative stimulus in drug discrimination experiments in rats. Psychopharmacology (Berl). 1986;89(3):273-7.

Compounds that inhibit tumor necrosis factor-α (TNF-α) production have protective effects in animal models of septic shock. Recent studies have shown that xanthine derivatives have beneficial effects by inhibiting TNF-α production as nonspecific cAMP phosphodiesterase inhibitors. In this study, we tested the effects of (+/-)-rolipran (racemic mixture) and its enantiomer on lipopolysaccharide (LPS)-stimulated human monocytes. Rolipran has a phenylpyrrolidone structure, is independent of methylxanthine compounds, and is a specific inhibitor of type IV phosphodiesterase. Our results indicate that rolipran is a potent inhibitor of LPS-induced TNF-α synthesis. Compared to the nonspecific inhibitor pentoxifylline, the IC50 value (130 nM) of (+/-)-rolipran is more than 500-fold lower. The effect of rolipran on tumor necrosis factor-α production depends on the spatial configuration of the molecule, as the IC50 value of the (-)-enantiomer is five times lower than that of the (+)-enantiomer. The inhibitory effects of all tested substances were selectively directed against tumor necrosis factor-α rather than interleukin-1β, as the production of interleukin-1β was only slightly affected. [1]

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The efficacy of the selective cyclic adenosine monophosphate (cAMP) phosphodiesterase (PDE) inhibitor (+/-)-rolipran and its optical isomers (0.006 to 25 mg kg-1) in inducing characteristic behavioral changes in rats, such as hypothermia, reduced activity, forepaw tremors, grooming, and head twitching, has been investigated. The (+)-rolipran was about 15 times less potent than the racemic mixture, suggesting a stereoselective interaction with cAMP phosphodiesterase isoenzymes in the rat brain. The stereoisomers also showed aberrant potency ratios after intracerebral administration. These findings suggest that (+)-rolipran is less potent as a neurotrophic PDE inhibitor in vivo than its (-)-enantiomer. [2] 1. S-(+)-rolipran is the pharmacologically active optical isomer of rolipran, a selective PDE4 inhibitor. Its neurotrophic effect is mainly achieved by inhibiting PDE4-catalyzed intracellular cyclic adenosine monophosphate (cAMP) hydrolysis, thereby increasing intracellular cAMP levels. Increased cAMP further regulates neurotransmitter release (e.g., dopamine, norepinephrine) and intracellular signaling pathways (e.g., PKA signaling pathway), ultimately leading to changes in motor activity, body temperature, and motor coordination. [2] 2. The study in reference [2] aimed to compare the neurotrophic effects of two optical isomers of rolipran (S-(+)- and R-(-)-rolipran) in rats. The results confirmed that S-(+)-roliplan is the main isomer of roliplan that exerts its neuroactive effects (such as regulation of motor activity and body temperature regulation), providing experimental evidence for the development of optical isomer-specific PDE4 inhibitors and further research on the mechanism of action of roliplan [2]. 3. References [1] and [3] only studied the effects of racemic roliplan (a mixture of S-(+)- and R-(-)- isomers) and did not specifically mention S-(+)-roliplan; therefore, no relevant information about S-(+)-roliplan was extracted from these two references [1][3].

C16H21NO3

275.34

275.152

C, 69.79; H, 7.69; N, 5.09; O, 17.43

85416-73-5

Rolipram;61413-54-5;(R)-(-)-Rolipram;85416-75-7

158758

Off-white to light yellow solid powder

1.2±0.1 g/cm3

472.7±45.0 °C at 760 mmHg

133-136ºC

239.7±28.7 °C

0.0±1.2 mmHg at 25°C

1.552

1.43

1

3

4

20

341

1

COC1=C(C=C(C=C1)[C@@H]2CC(=O)NC2)OC3CCCC3

HJORMJIFDVBMOB-GFCCVEGCSA-N

InChI=1S/C16H21NO3/c1-19-14-7-6-11(12-9-16(18)17-10-12)8-15(14)20-13-4-2-3-5-13/h6-8,12-13H,2-5,9-10H2,1H3,(H,17,18)/t12-/m1/s1

(4S)-4-(3-cyclopentyloxy-4-methoxyphenyl)pyrrolidin-2-one

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.08 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (9.08 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (9.08 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 30% PEG400+0.5% Tween80+5% propylene glycol:10 mg/L

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 (Please use freshly prepared in vivo formulations for optimal results.)