Antioxidant and antimutagenic properties of the monoterpene indole alkaloid psychollatine and the crude foliar extract of Psychotria umbellata Vell. - Fragoso,V.; Nascimento,N.C.; Moura,D.J.; Silva,A.C.R.; Richter,M.F.; Saffi,J.; Fett-Neto,A.G. (Toxicol In Vitro, 2008)