Uricase (urate oxidase) is an enzyme that stimulates the oxidation of uric acid to allantoin. The lack of this enzyme in humans results in high uric acid blood levels (hyperuricemia) and gout. Uric acid levels in humans can be 10 times high as in other animals.
Reduced urate oxidase activity in humans is due to a genetic mutation, which occurred in our ancient ancestors. This results in reduced metabolism of uric acid and hyperuricemia. Usually, elevated uric acid levels have been avoided in humans by a second mutation responsible for the production of xanthine oxidoreductase (xanthine oxidase), an enzyme that regulates the production of uric acid from purines. In some people this balance is not maintained and elevated hyperuricemia results.
Uric acid is a strong antioxidant and may protect the human body from oxidative damage, which could have strong antioxidant protection for the human brain. It may also increase the human life span and reduce cancer rates.
CONCLUSION: Uric acid levels are delicately balanced in humans. Uric acid elevations are shown to be the result of ancient DNA mutations changing the expression of the enzyme that metabolizes uric acid (uricase). Gouty arthritis and other problems of hyperuricemia, such as vascular disease, can result. This genetic elevation is balanced, to some extent, by co-evolution of the down-regulation of a gene responsible for production of an enzyme that regulates uric acid production (xanthine oxidase).
NOTE: Certain herbs have been shown to reduce uric acid levels by reducing xanthine oxidase activity. Flavonoids, black tea, astragulus, cocoa polyphenols and white mulberry twigs have been shown to have xanthine oxidase inhibitor activity, reducing uric acid production and preventing gout.