Icariin (Ieariline) belongs to the flavonol glycoside group of natural products, can inhibit PDE5 and PDE4 activity (IC50=432/73.50 μM), is also a PPARα activator. Icariin can increase cardiovascular and cerebrovascular blood flow, promote hematopoiesis, immunity and bone metabolism.

Astragaloside IV (AS-IV), an active component isolated from Astragalus membranaceus, suppresses the activation of ERK1/2 and JNK, and downregulates matrix metalloproteases (MMP)-2, (MMP)-9 in MDA-MB-231 breast cancer cells. Astragaloside IV is a bioactive saponin first isolated from the dried plant roots of the genus Astragalus, which is used in traditional Chinese medicine.1 It dose-dependently inhibits human adenovirus type 3 (HAdV-3) in A549 cells (IC50 = 23 μM; LC50 = 865 μM).It inhibits replication of HAdV-3 and decreases HAdV-3-induced apoptosis. It has diverse protective effects for the cardiovascular, immune, digestive, and nervous systems. In particular, it reduces myocardial infarct size in dogs when administered prior to coronary ligation and reduces reperfusion arrhythmias in isolated rat hearts.

Theophylline monohydrate (Quibron) appears to inhibit phosphodiesterase and prostaglandin production, regulate calcium flux and intracellular calcium distribution, and antagonize adenosine. Theophylline monohydrate is a natural alkaloid derivative of xanthine isolated from the plants Camellia sinensis and Coffea arabica. Physiologically, this agent relaxes the bronchial smooth muscle, produces vasodilation (except in cerebral vessels), stimulates the CNS, stimulates the cardiac muscle, induces diuresis, and increases gastric acid secretion; it may also suppress inflammation and improve contractility of the diaphragm.

Theophylline (1,3-Dimethylxanthine) is a methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac, and central nervous system stimulant activities. It inhibits the 3', 5'-cyclic nucleotide phosphodiesterase that degrades cyclic AMP, thus potentiating the actions of agents that act through adenylyl cyclases and cyclic AMP.

Indomethacin (Indomethacin) is a COX1 and COX2 inhibitor (IC50=18/26 nM) with blood-brain barrier permeability and non-selectivity. Indomethacin is a non-steroidal anti-inflammatory agent with anti-tumor and anti-infective activity.

Isoprenaline hydrochloride (NCI-c55630) is a potent beta-adrenergic agonist with the peripheral vasodilator, bronchodilator, and cardiac stimulating properties.

Roflumilast (APTA 2217) is an orally available, long-acting inhibitor of phosphodiesterase (PDE) type 4 (PDE4), with anti-inflammatory and potential antineoplastic activities. Upon administration, roflumilast and its active metabolite roflumilast N-oxide selectively and competitively bind to and inhibit PDE4, which leads to an increase of both intracellular levels of cyclic-3', 5'-adenosine monophosphate (cAMP) and cAMP-mediated signaling.

Vardenafil hydrochloride is a New Phosphodiesterase Type 5(PDE5) Inhibitor, in the Treatment of Erectile Dysfunction in Men With Diabetes