Febuxostat (ULORIC) is a novel, xanthine oxidase/dehydrogenase (XO/XDH) inhibitor being developed by Teijin, TAP Pharmaceuticals, and Ipsen for the treatment of gout. The currently available XO inhibitor, allopurinol, has been associated with serious instances of severe hypersensitivity, in some cases leading to fatalities. There is some suggestion that febuxostat is less prone to excacerbate systemic inflammatory events in animal studies. Febuxostat, a xanthine oxidase inhibitor, achieves its therapeutic effect by decreasing serum uric acid. Febuxostat is not expected to inhibit other enzymes involved in purine and pyrimidine synthesis and metabolism at therapeutic concentrations. Febuxostat is used for the treatment of hyperuricemia in patients with gout.

Allopurinol is a xanthine oxidase inhibitor used to decrease high blood uric acid levels. Allopurinol is specifically used to prevent gout, prevent specific types of kidney stones, and for the high uric acid levels that can occur with chemotherapy. Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation. Allopurinol is a structural analog of the natural purine base, hypoxanthine. It is an inhibitor of xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and of xanthine to uric acid, the end product of purine metabolism in man. Allopurinol is metabolized to the corresponding xanthine analog, oxypurinol (Allopurinol), which also is an inhibitor of xanthine oxidase. Allopurinol is taken by mouth or injected into a vein. Common side effects, when used by mouth, include itchiness and rash. Common side effects when used by injection include vomiting and kidney problems.

Secoisolaricircsinol is one of the most abundant dietary lignans in various foods, such as plant seeds, whole grains, legumes, vegetables, and fruits. Secoisolariciresinol is the major lignin found in flaxseed and is present in a polymer that contains Secoisolariciresinol diglucoside. Secoisolariciresinol and Secoisolariciresinol diglucoside are known to have a number of health benefits, including reduction of the serum cholesterol levels, delaying of the onset of type 2 diabetes, and reduction of the formation of hormone-sensitive cancers such as breast, prostate, and colon cancers. Following the consumption of Secoisolariciresinol diglucoside, it is further converted by the bacteria in the colon of humans and other animals into aglycone Secoisolariciresinol and the mammalian lignans, enterodiol and enterolactone. The structures of enterodiol and enterolactone are similar to that of estradiol, an endogenous estrogen. This structural similarity accounts for the ability of these compounds to bind to estrogen receptors and to exert weak estrogenic or anti-estrogenic effects, depending on the presence of stronger estrogen. It is well known that Secoisolariciresinol has an estrogen-like activity and stimulates the cell growth of human breast cancer MCF-7 cells.

Y-700 (Niraxostat or 1-[3-Cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid) is an inhibitor of xanthine oxidoreductase. Y-700 demonstrated high oral bioavailability being predominantly eliminated via the liver. It potently reduces serum uric acid levels. Y-700 was in clinical trials for the treatment of gout.

D-(+)-Neopterin (D-monapterin, Monapterin) is a pteridine derivative, naturally found in Dictyostelium discoideum and in the urine of cancer patients.

(1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) is a β-carboline indole alkaloid naturally occurring in plants, foods, insects, and endogenously in mammals and humans. It exerts antioxidant and antithrombotic properties. MTCA is thought to be a possible causative substance of eosinophilia-myalgia syndrome associated with ingestion of L-tryptophan.

Isoacteoside (2-(3′,4′-dihydroxyphenyl)ethyl 6-O-caffeoyl-3-O-(α-l-rhamnopyranosyl)-β-d-glucopyranoside), a phenylethanoid glycoside isomeric to acteoside, exists in various plants, such as Cistanches spp., Castilleja spp. and Plantago spp. It exerts wide range of pharmacological activity including anti-inflammatory and cytoprotective actions.