姜黄素治疗老年痴呆研究困境及其对策

Dilemma and Countermeasures in the Research on Curcumin as a Drug against Senile Dementia

虽然老年痴呆病因及发病机制尚不清楚,但是许多体外、动物实验证明姜黄素能抑制导致老年痴呆发生的病理因素、保护脑神经。小样本、短期人体试验却显示姜黄素对于老年痴呆没有治疗作用。造成这个结果可能有3个原因:第一,与动物大脑比较,人的大脑容量大、结构复杂。老年痴呆对人大脑的损害会更大,更全面,因此短期的临床试验可能无法显示效果。第二,姜黄素可能只有预防而没有治疗老年痴呆的作用。第三,姜黄素在脑内的血药浓度低,起不到治疗作用。通过分析已经完成的人体试验,发现均为使用姜黄素粉末制成胶囊或者颗粒。由于姜黄素稳定性差、水溶性差、生物利用度低,因此试验结果不佳。只有使用脑靶向制剂,增加姜黄素脑内的浓度来进行长期的人体试验,才能确定姜黄素是否有治疗老年痴呆的作用。

The etiology and pathogenesis of senile dementia are still unclear,while the inhibition against pathological factors and the protection of brain nerve of curcumin has been confirmed by in vitro and animal studies. However,some human trials with small sample and short term showed the negative results. Three reasons can be responsible for the discrepancy： firstly,compared with animal brain,human brain is more complicated with larger capacity. Senile dementia is more harmful to human brain,therefore,short-term human studies can not show positive results; secondly,curcumin may only have preventive activity without therapeutic action in the treatment of senile dementia; finally,low brain concentration of curcumin can not show sufficient therapeutic effect. The finished human studies all applied capsules and granule made from curcumin raw powder and the unsatisfactory study results may be caused by the poor stability,solubility and bioavailability of curcumin. Therefore,brain-targeting preparations of curcumin should be used in the long-term human studies,which may increase the curcumin concentration in brain in order to judge the efficacy of curcumin for senile dementia.