Forskolin, Coleus forskohlii

A cardioactive diterpene isolated from the Indian plant Coleus forskolii. At low doses, acts as a positive inotropic agent in dogs, cats, spontaneously hypertensive and normal rats, and isolated guinea pig heart. At higher doses, acts as a hypotensive and vasodilatory agent due to its action as a smooth muscle relaxant. No major side effects are observed at effective doses. Rapid and reversible activator of adenylate cyclase (EC₅₀ = 4 µM) in membranes and intact cells. Does not affect the activity of guanylate cyclase or cyclic nucleotide phophodiesterases. The exact mechanism of forskolin′s positive inotropic effect is unknown but may be related to a cAMP-dependent increase in Na⁺ permeability, which results in indirect augmentation of Ca²⁺ release. Inhibits MAP kinase in rat renal mesangial cells (IC₅₀ = 25 µM). Also acts as a Hh pathway antagonist. Shown to inhibit apoptosis in cerebellar granule cells and to induce apoptosis in resting human B-lymphocytes.

The major cell-permeable diterpene isolated from the Indian plant Coleus forskohlii. At low doses, it acts as a positive inotropic agent. At higher doses, it serves as a hypotensive and vasodilatory agent due to its actions as a smooth muscle relaxant. No major side effects are observed at effective doses. Forskolins pharmacological activities are due to its activation of adenylate cyclase (EC₅₀ = 4 µM), resulting in increased cAMP levels. The exact mechanism of forskolins positive inotropic effect is unknown but may be related to a cAMP-dependent increase in Na⁺ permeability that results in indirect augmentation of Ca²⁺ release. Inhibits MAP kinase in rat renal mesangial cells (IC₅₀ = 25 µM). Also acts as a Hh pathway antagonist. Shown to inhibit apoptosis in cerebellar granule cells and to induce apoptosis in resting human B lymphocytes.

Cell permeable: yes

Product does not compete with ATP.

Reversible: no

Target IC₅₀: 25 µM inhibiting MAP kinase in rat renal mesangial cells; EC50 = 4 µM for activation of adenylate cyclase

Ethanol is reported to inhibit forskolin-mediated activation of adenylate cyclase. DMSO is the recommended solvent; at ≤5% DMSO final concentration, little inhibition of the adenylate cyclase activation will occur.

Toxicity: Harmful (C)

Following reconstitution, store in the refrigerator (4°C). DMSO stock solutions are stable for up to 4 months at 4°C.

D′Orazio, J.A., et al. 2006. Nature443, 340.
Noveen, A., et al. 1996. Biochem. Biophys. Res. Commun.219, 180.
Galli, C., et al. 1995. J. Neurosci.15, 1172.
Li, X., et al. 1995. Am. J. Physiol.269, C986.
Lomo, J., et al. 1995. J. Immunol.154, 1634.
Uneyama, H., et al. 1993. J. Biol. Chem.268, 168.
Laurenza, A., et al. 1989. Trends Pharmacol. Sci.10, 442.
Adashi, E.Y., and Resnick, C.E. 1986. J. Cell. Biochem.31, 217.
Seamon, K.B., and Daly, J.W. 1986. Adv. Cyclic Nucleotide Protein Phosphorylation Res.20, 1.
Huang, R., et al. 1982. Cyclic Nucleotide Res.8, 385.
Metzger, H., and Lindner, E. 1981. IRCS Med. Sci. Biochem. Cardiovasc. System Pharmacol.9, 99.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany