Department of Clinical Pharmacy and Pharmacology, University of Dhaka, Bangladesh.
J Ethnopharmacol. 2013 Jul 30;148(3):780-6. doi: 10.1016/j.jep.2013.05.004. Epub 2013 May 21.
Experimental evidences have demonstrated that Nigella sativa Linn. seed (NS) has positive modulation effects on aged rats with memory impairments, prevents against hippocampal pyramidal cell loss and enhances consolidation of recall capability of stored information and spatial memory in rats. NS has neuroprotective, nephroprotective, lung protective, cardioprotective, hepatoprotective activities as established by previous studies on animals. Several clinical trials with NS on human have also demonstrated beneficial effect.
The present study was designed to investigate the effects of NS on memory, attention and cognition in healthy elderly volunteers. Furthermore, safety profile of NS was assessed during the nine-week study period.
Forty elderly volunteers were recruited and divided randomly into group A and group B--each consisting of 20 volunteers. The treatment procedure for group A was 500 mg NS capsule twice daily for nine weeks and Group B received placebo instead of NS in the similar manner. All the volunteers were assessed for neuropsychological state and safety profile twice before treatment and after nine weeks. The neuropsychological tests were logical memory test, digit span test, Rey-Osterrieth complex figure test, letter cancellation test, trail making test and stroop test. Safety profile was assessed by measuring biochemical markers of Cardiac (total cholesterol, triglycerides and high density lipoprotein cholesterol, very low density lipoprotein, low density lipoprotein cholesterol, creatine kinase-MB); Liver (aspartate aminotransferase, alanin aminotransferase, alkaline phosphatase, total protein, albumin, bilirubin) and Kidney (creatinine and blood urea nitrogen) through using commercial kits.
There was significant difference (p<0.05) in the score of logical memory test-I and II, total score of digit span, 30 min delayed-recall, percent score in Rey-Osterrieth complex figure test, time taken to complete letter cancellation test, time taken in trail making test-A and test-B, score in part C of stroop test due to ingestion of NS for nine weeks. There were not statistically significant changes (p>0.05) in any of the biochemical markers of cardiac, liver, kidney function during this nine-week study period.
The current study demonstrates the role of NS in enhancing memory, attention and cognition. Therefore, whether NS could be considered as potential food supplement for preventing or slow progressing of Alzheimer disease needs further investigations. However, study with Alzheimer's patients with large population size for longer period of time is recommended before using NS daily and extensive phytochemical investigations are recommended for novel drug discovery from NS for treating cognitive disorders.
实验证据表明，黑种草子（NS）对记忆障碍的老年大鼠具有积极的调节作用，可防止海马锥体神经元丢失，并增强大鼠对存储信息的回忆能力和空间记忆的巩固。先前的动物研究表明，NS 具有神经保护、肾保护、肺保护、心脏保护和肝脏保护作用。几项关于人类的 NS 临床试验也证明了其有益效果。
本研究旨在研究 NS 对健康老年人的记忆、注意力和认知的影响。此外，还在九周的研究期间评估了 NS 的安全性概况。
招募了 40 名老年人志愿者，并将他们随机分为 A 组和 B 组，每组各 20 名志愿者。A 组的治疗程序是每天服用 500 毫克 NS 胶囊两次，共九周；B 组则以类似的方式服用安慰剂代替 NS。所有志愿者在治疗前和九周后两次接受神经心理学状态和安全性评估。神经心理学测试包括逻辑记忆测试、数字跨度测试、 Rey-Osterrieth 复杂图形测试、字母删除测试、连线测试和 Stroop 测试。通过使用商业试剂盒，测量心脏（总胆固醇、甘油三酯和高密度脂蛋白胆固醇、极低密度脂蛋白、低密度脂蛋白胆固醇、肌酸激酶-MB）、肝脏（天门冬氨酸氨基转移酶、丙氨酸氨基转移酶、碱性磷酸酶、总蛋白、白蛋白、胆红素）和肾脏（肌酐和血尿素氮）的生化标志物来评估安全性概况。
服用 NS 九周后，逻辑记忆测试 I 和 II 的得分、数字跨度总分、30 分钟延迟回忆、 Rey-Osterrieth 复杂图形测试的百分比得分、字母删除测试完成时间、连线测试 A 和 B 的时间、Stroop 测试 C 部分的得分均有显著差异（p<0.05）。在这九周的研究期间，心脏、肝脏、肾脏功能的任何生化标志物均无统计学意义上的变化（p>0.05）。
本研究表明 NS 具有增强记忆、注意力和认知的作用。因此，NS 是否可以被认为是预防或减缓阿尔茨海默病进展的潜在食品补充剂，还需要进一步研究。然而，建议在每天使用 NS 之前，用更大的人群进行更长时间的研究，并建议进行广泛的植物化学研究，从 NS 中发现治疗认知障碍的新药。
