The dark side of curcumin.

摘要: Dear Editor, Curcumin is a yellow–orange pigment obtained from the plant Curcuma longa. The powdered rhizome of this plant, called turmeric, common ingredient in curry powders and has long history use traditional Asian medicine for wide variety disorders. In last decade large number reports have been published on beneficial effects curcumin, it repeatedly claimed that natural product efficient safe prevention treatment several diseases including cancer. It not surprising, therefore, curcumin currently sold as dietary supplement numerous clinical trials are ongoing or recruiting participants to evaluate activity. But there accumulating evidence may be so effective safe. Because such generally acknowledged, purpose letter briefly review negative properties they can balanced against its effects. Most supports therapeutic potential mainly based vitro studies which was tested at concentrations micromolar range. Several demonstrated, however, plasma people taking relatively high oral doses compound very low, typically nanomolar range (reviewed Ref. 4). For instance, recent study examined pharmacokinetics preparation 12 healthy human volunteers 0.25–72 hr after an dose 10 g. Using high-performance liquid chromatography assay with limit detection 50 ng mL , only 1 subject had detectable free any time points assayed. fact also undergoes extensive metabolism intestine liver means cannot achieved maintained tissues ingestion. This major obstacle development agent suggests limited. low efficiency chronic Alzheimer’s disease cardiovascular discussed recently. As far cancer concerned, demonstrated cells do die unless exposed 5–50 lM hours. poor bioavailability, these outside gastrointestinal tract when taken orally. liver, hours tract. chemotherapeutic limited even cancers Accordingly, 15 patients advanced colorectal were treated daily 3.6 g up 4 months, no partial responses decreases tumor markers observed. A search website www.clinicaltrials.gov July 2009 showed 34 using diseases, particularly some trials, types receiving will receive through route. Phase II trial (NCT00094445), pancreatic 8 by mouth every day 8-week-periods. before, administration does lead cytotoxic If one assumes cell death necessary achieve response, should expect positive outcome trial. Trial test if improve efficacy standard chemotherapy gemcitabine locally metastatic adenocarcinoma pancreas (NCT00192842). rationale vivo data suggest noncytotoxic sensitize anticancer drugs gemcitabine. Although kg increased antitumor orthotopic model cancer, (e.g. 70 70-kg person) almost times higher than used testing combination (8 g). makes uncertain, either increase reduce depending concentration used. strategies proposed overcome bioavailability curcumin. One entered consists black pepper alkaloid piperine (bioperine) strategy, cautiously, potent inhibitor drug Le tt er s th e E di r