Chemicals & Small Molecules

HC Toxin is a reversible, cell-permeable inhibitor of HDACs. It is a cyclic tetrapeptide first isolated from C. carbonum, a maize pathogen. It up-regulates the expression of 15-lipoxygenase-1 in colorectal cancer cells and has been shown to induce fetal hemoglobin in human primary erythroid cells.

Suberohydroxamic acid (SBHA) is a competitive HDAC inhibitor. SBHA has been shown to cause cell differentiation, cell cycle arrest, and apoptosis.

LY171883 is a PDE inhibitor and a selective, potent inhibitor of the leukotriene D4 receptor. Also, LY171883 binds to the PPAR nuclear receptor at 50-100 ?M and induces adipogenesis in cultured NIH3T3 fibroblasts.

IBMX, also known as 1-Methyl-3-Isobutylxanthine and Isobutylmethylxanthine, is a widely-used inhibitor of cAMP and cGMP PDEs. It has been shown that the increase in cellular cAMP and cGMP levels, resulting from the inhibition of PDEs by IBMX, activates cyclicnucleotide-regulated protein kinases. IBMX does not inhibit PDE8A, PDE8B, or PDE9.

Quercetin is an inhibitor of PDEs of both cAMP and cGMP. It is a flavonoid found in plant and fruit bark or rinds. It is estimated that normal dietary intake of Quercetin for humans is 0.1-0.2 mg/kg. Quercetin can induce renal adenomas in male rats when fed at 2,000 mg/kg.

BAY-60-7550 is a potent inhibitor of PDE2. It is more selective for PDE2 than PDE1 by 50-fold. Similarly, it is 100-fold more selective for PDE4B, PDE5B, PDE7B, PDE8A, PDE9A, PDE10A, and PDE11A.

Milrinone, also known as WIN 47203 and Primacor®, is an inhibitor of PDE3. It is less effective against other PDE isoforms. Milrinone has positive inotropic and vasodilatory effects in vivo.

Icariin is a PDE5 inhibitor. It is the active component of the Chinese medicinal plant E. brevicornum. It can induce differentiation of cardiomyocytes and upregulates the expression of cardiac genes. Icariin increase the proliferation and differentiation of cultured human osteoblasts, which appears to be mediated in part by upregulating bone morphogenetic protein 2 mRNA.

Zaprinast is a cGMP-specific PDE inhibitor which moderately inhibits PDE5 and PDE6. It weakly inhibits PDE9, PDE10 and PDE11. Sildenafil (Viagra™) was developed from Zaprinast, which enhances the vasodilatory effects of nitric oxide in a range of vascular tissues by prolonging the cGMP-mediated activation of cGMP-dependent protein kinase. Also, GPR35 is activated by Zaprinast.