Bin Sayeed MS, Asaduzzaman M, Morshed H, Hossain MM, Kadir MF, Rahman MR.
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.
AIM OF THE STUDY:
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.
Bin Sayeed MS, Shams T, Fahim Hossain S, Rahman MR, Mostofa A, Fahim Kadir M, Mahmood S, Asaduzzaman M.
J Ethnopharmacol. 2014 Feb 27;152(1):156-62. doi: 10.1016/j.jep.2013.12.050. Epub 2014 Jan 8.
Previous studies conducted on animals linked consumption of Nigella sativa L. seeds (NS) to decreased anxiety and improved memory. The present study, which was carried out at a boarding school in Bangladesh, was designed to examine probable effect of NS on mood, anxiety and cognition in adolescent human males.
MATERIALS AND METHODS:
Forty-eight healthy adolescent human males aged between 14 to 17 years were randomly recruited as volunteers and were randomly split into two groups: A (n=24) and B (n=24). The treatment procedure for group A and B were one capsule of 500 mg placebo and 500 mg NS respectively once daily for four weeks. All the volunteers were assessed for cognition with modified California verbal learning test-II (CVLT-II), mood with Bond-Lader scale and anxiety with State-Trait Anxiety Inventory (STAI) at the beginning and after four weeks of either NS or placebo ingestion.
RESULTS AND DISCUSSION:
No parameter showed statistically significant variation between A and B in measurements in the beginning, but after 4 weeks of one capsule of NS 500 mg intake, there was statistically significant variation of mood within group B but there was not statistically significant variation between group A and B. No significant variation was found in state anxiety within groups and between group A and B but in case of trait anxiety, significant variation was found within group B but not between group A and B. In case of CVLT II, there was significant variation within B in immediate short-term recall at trial 4 and 5 whereas this difference was found only in case of trial 5 between group A and B. Within group B, short term-free recall, long-term free recall and long-term cued recall had statistical difference whereas between group A and B long-term free recall and long-term cued recall had statistical difference. No parameters had significant variation within group A after placebo intake for 4 weeks.
Over the 4 weeks study period, the use of NS as a nutritional supplement been observed to- stabilize mood, decrease anxiety and modulate cognition positively. However, long term study is suggested before using NS extensively.
Azzubaidi MS, Saxena AK, Talib NA, Ahmed QU, Dogarai BB.
Acta Neurobiol Exp (Wars). 2012;72(2):154-65.
The fixed oil of black cumin seeds, Nigella sativa L. (NSO), has shown considerable antioxidant and anti-inflammatory activities. Chronic cerebral hypoperfusion has been linked to neurodegenerative disorders including Alzheimer’s disease (AD) and its subsequent cognitive impairment in which oxidative stress and neuroinflammation are the principal culprits. Cerebrovascular hypoperfusion was experimentally achieved by bilateral common carotid arteries occlusion (2VO) in rats. Morris water maze (MWM) test was employed to assess the effects of NSO on spatial cognitive function before and after 2VO intervention. Rats were divided into long-term memory (LTM) and short-term memory (STM) groups, each was further subdivided into 3 subgroups: sham control, untreated 2VO and NSO treated 2VO group. All subgroups were tested with MWM at the tenth postoperative week. Working memory test results for both sham control and NSO treated groups showed significantly lower escape latency time and total distance travelled than untreated 2VO group. Similarly, LTM and STM MWM tests for sham control and NSO treated groups revealed significantly better maze test performance as compared to untreated 2VO group. Sham control and NSO treated 2VO groups demonstrated superior probe memory test performance as compared to untreated 2VO group. The fixed oil of Nigella sativa seeds has demonstrated noticeable spatial cognitive preservation in rats challenged with chronic cerebral hypoperfusion which indicates a promising prospective neuroprotective effect
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