Phytother Res. 2009 Dec;23(12):1790-1.
Xanthine oxidase inhibiting effects of noni (Morinda citrifolia) fruit juice. 
Palu A, Deng S, West B, Jensen J.

Tahitian Noni Juice, noni fruit juice concentrate and noni fruit puree extract inhibited xanthine oxidase in vitro. (original abstract available at https://www.ncbi.nlm.nih.gov/pubmed/19434757).