Panobinostat (NVP-LBH589) is a broad-spectrum HDAC inhibitor (IC50=5 nM) with oral activity and non-selectivity. Panobinostat has antitumor activity and induces apoptosis and autophagy.

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.

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.

Vorinostat (SAHA) is a pan-histone deacetylase (HDAC) inhibitor (IC50=10 nM) with inhibitory activity against HDAC1/2/3/6/7/11. Vorinostat has antitumor activity, induces cell differentiation, blocks the cell cycle and induces apoptosis.

Acefylline (Theophylline-7-acetic acid), a stimulant drug of the xanthine chemical class, acts as an adenosine receptor antagonist. It is combined with diphenhydramine in the pharmaceutical preparation Etanautine to help offset its stimulant effects

The inhibitory effect of Methyl L-histidinate dihydrochloride (L-Histidine methyl ester dihydrochloride) on histidine decarboxylase in Sprague-Dawley rat stomach assessed as decrease in 14CO2 production with activty value of 1.8 μM

Parthenolide ((-)-Parthenolide) is a natural sesquiterpene lactone that is an NF-κB inhibitor and also specifically inhibits HDAC1 protein, but is inactive against other class I/II HDACs. Parthenolide has anti-inflammatory, anti-tumor, and anti-viral activities.