Effect of Nigella sativa and wheat germ oils on scopolamine-induced memory impairment in rats

Sterubin protects against chemically-induced Alzheimer's disease by reducing biomarkers of inflammation- IL-6/ IL-β/ TNF-α and oxidative stress- SOD/MDA in rats

Sterubin, a flavanone is an active chemical compound that possesses neuroprotective activity. The current investigation was intended to assess the sterubin effect in scopolamine-activated Alzheimer's disease. The rats were induced with scopolamine (1.5 mg/kg) followed by treatment with sterubin (10 mg/kg) for 14 days. Behavioural analysis was predictable by the Y-maze test and Morris water test. Biochemical variables like nitric oxide acetylcholinesterase, Choline acetyltransferase, antioxidant markers like superoxide dismutase, glutathione transferase, malondialdehyde, catalase, and myeloperoxidase activity, neuroinflammatory markers such as tumor necrosis factor-alpha, nuclear factor kappa B, interferon-gamma, interleukin (IL-1β), and IL-6 were measured. The result stated that sterubin reversed the oxidative stress parameters, increased motor performance, and lowered the inflammatory markers in scopolamine-induced rats. The study demonstrated that sterubin possesses neuroprotective, anti-inflammatory, and antioxidant properties which can be used as a beneficial medication in AD.

Neuroprotective Effects of the Ethanolic Leaf Extract of Crassocephalum crepidioides (Asteracaeae) on Diazepam-Induced Amnesia in Mice

This study aimed to evaluate the neuroprotective effects of the ethanolic leaf extract of Crassocephalum crepidioides (Cc) on diazepam-induced amnesia in mice. Thirty mice distributed into six groups of five mice each were used. The normal control and negative control groups received 2% ethanol per os, the positive control group received piracetam (150 mg/kg, p.o), and three experimental groups were treated with three doses of ethanolic leaf extract of Cc (100, 200, and 400 mg/kg, p.o). All groups except the normal control group were co-treated with diazepam (3 mg/kg, i.p) daily for 14 days. The memory effects were evaluated using the Radial Arm Maze (RAM) and the Novel Object Recognition (NOR) tests, while the anti-depressive effects were evaluated using the tail suspension test. All animals were sacrificed at the end of the study. Hippocampi, isolated from the right hemisphere, were used to prepare a homogenate for the determination of oxidative stress biomarkers. The ethanolic leaf extract of cc significantly (p < 0.001) decreased the number of working and reference memory errors in the RAM test and induced a significant (p < 0.01) increase in the time spent exploring the novel object in the NOR test. The extract also induced a significant (p < 0.001) increase in the mobility time in tail suspension. Moreover, compared to the negative control group, the extract significantly (p < 0.01) increased superoxide dismutase activity and significantly (p < 0.01) decreased malondialdehyde levels. The histopathological analysis of hippocampi showed that the cc extract increased cell density when compared with the negative control. These results suggest that the ethanolic left extract of cc could have neuroprotective properties, which could be attributed to its antioxidant properties.

Neuroprotective role of medicinal plant extracts evaluated in a scopolamine-induced rat model of Alzheimer's disease

BackgroundAlzheimer's disease is a debilitating neurological brain disease with memory impairment among the first signs. Scopolamine (SCO), a muscarinic receptor antagonist that disrupts cognition and memory acquisition, is considered a psychopharmacological AD model. We investigate the effectiveness of medicinal plants in mitigating the SCO-induced neurobehavioural damage in rats.Materials and MethodsAnimals were injected with Scopolamine hydrobromide trihydrate (2.2 mg/kg IP.) daily for 2 months. Each treatment group was administered one of four medicinal spice extracts (Nigella sativa, 400 mg/kg; rosemary, 200 mg/kg; sage, 600 mg/kg and ginseng;200 mg/kg 90 minutes after SCO injection. Animals were subjected to cognitive-behavioral tests (NOR, Y-maze, and MWM). After the experiment, we extracted the brains for histopathological examination and biochemical assessment for oxidative stress (levels of TT, CAT and TBARS) and gene expression of acetylcholinesterase and brain monoamines.ResultsAs expected, SCO treatment impaired memory and cognition, increased oxidative stress, decreased neurotransmitters, and caused severe neurodegenerative changes in the brain.ConclusionSurprisingly, these effects were measurably moderated by the administration of all four plant extracts, indicating a neuroprotective action that we suggest could alleviate AD disease manifestations.

Thymol ameliorated neurotoxicity and cognitive deterioration in a thioacetamide-induced hepatic encephalopathy rat model; involvement of the BDNF/CREB signaling pathway

In the present study, we aimed to delineate the neuroprotective potential of thymol (THY) against neurotoxicity and cognitive deterioration induced by thioacetamide (TAA) in an experimental model of hepatic encephalopathy (HE). Rats received TAA (100 mg kg^-1, intraperitoneally injected, three times per week) for two weeks. THY (30 and 60 mg kg^-1), and Vit E (100 mg k^-1) were administered daily by oral gavage for 30 days after HE induction. Supplementation with THY significantly improved liver function, reduced serum ammonia level, and ameliorated the locomotor and cognitive deficits. THY effectively modulated the alteration in oxidative stress markers, neurotransmitters, and brain ATP content. Histopathology of liver and brain tissues showed that THY had ameliorated TAA-induced damage, astrocyte swelling and brain edema. Furthermore, THY downregulated NF-kB and upregulated GFAP protein expression. In addition, THY significantly promoted CREB and BDNF expression at both mRNA and protein levels, together with enhancing brain cAMP level. In conclusion, THY exerted hepato- and neuroprotective effects against HE by mitigating hepatotoxicity, hyperammonemia and brain ATP depletion via its antioxidant, anti-inflammatory effects in addition to activation of the CREB/BDNF signaling pathway.

Antioxidant and Anticholinesterase Properties of the Aqueous Extract of Balanites aegyptiaca L. Delile Fruit Pulp on Monosodium Glutamate-Induced Excitotoxicity in Swiss Mice

Balanites aegyptiaca L. Delile (B. aegyptiaca) is used in traditional medicine for the treatment of memory impairment. This work aims to evaluate the antioxidant and anticholinesterase potential of BA fruit pulp extract on excitotoxicity induced by monosodium glutamate (MSG). MSG was administered 30 minutes after treatment with B. aegyptiaca aqueous fruit pulp extract (50, 125, 250, and 500 mg/kg) and vitamin C (100 mg/kg) for 30 days. The negative control group received only MSG, while the control group was given distilled water daily. Behavioral tests parameters (using the novel object recognition, Y-maze, and Barnes maze tests), oxidative stress biomarkers (malondialdehyde, superoxide dismutase, and catalase), nitric oxide, and acetylcholinesterase activity and hippocampal architecture were evaluated. Results obtained revealed that different doses of B. aegyptiaca significantly reversed the deleterious effect of MSG on memory. This was displayed by a significant ( $p<0.05$ ) increment in the percentage of spontaneous alternation in the Y-maze test and a significant ( $p<0.001$ ) increase in discrimination index in novel object recognition observed with 500 mg/kg extract dose. Moreover, the extract (250 and 500 mg/kg doses) significantly ( $p<0.001$ ) increased direct search strategy and significantly decreased ( $p<0.01$ ) the time taken to find the target hole in the Barnes maze. A modulation of hyperactivity was observed after administration of all extract doses compared to the negative control group in the open arena. Furthermore, the highest dose of the extract caused a significant ( $p<0.001$ ) improvement in antioxidant enzymes activity, associated with a significant ( $p<0.001$ ) decrement in nitric oxide and malondialdehyde concentrations and a significant ( $p<0.01$ ) decrease in acetylcholinesterase activity. Treatment with the extract also restored normal hippocampal cell architecture. B. aegyptiaca fruit pulp extract could thus confer neuroprotection through its antioxidant and anticholinesterase potential.

Thymoquinone: Review of Its Potential in the Treatment of Neurological Diseases

Thymoquinone (TQ) possesses anticonvulsant, antianxiety, antidepressant, and antipsychotic properties. It could be utilized to treat drug misuse or dependence, and those with memory and cognitive impairment. TQ protects brain cells from oxidative stress, which is especially pronounced in memory-related regions. TQ exhibits antineurotoxin characteristics, implying its role in preventing neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease. TQ’s antioxidant and anti-inflammatory properties protect brain cells from damage and inflammation. Glutamate can trigger cell death by causing mitochondrial malfunction and the formation of reactive oxygen species (ROS). Reduction in ROS production can explain TQ effects in neuroinflammation. TQ can help prevent glutamate-induced apoptosis by suppressing mitochondrial malfunction. Several studies have demonstrated TQ’s role in inhibiting Toll-like receptors (TLRs) and some inflammatory mediators, leading to reduced inflammation and neurotoxicity. Several studies did not show any signs of dopaminergic neuron loss after TQ treatment in various animals. TQ has been shown in clinical studies to block acetylcholinesterase (AChE) activity, which increases acetylcholine (ACh). As a result, fresh memories are programmed to preserve the effects. Treatment with TQ has been linked to better outcomes and decreased side effects than other drugs.

Effect of Sanguisorba minor on scopolamine-induced memory loss in rat: involvement of oxidative stress and acetylcholinesterase

Sanguisorba minor (S. minor) has neuroprotective and antioxidant activities. However, its potential benefits in ameliorating learning and memory functions have been explored in no studies up to now. So, in the current study, rats were treated with S. minor hydro-ethanolic extract (50, 100, and 200 mg/kg, intraperitoneal (i.p.)) as well as rivastigmine (0.5 mg/kg, i.p.) for 21 consecutive days. Thereafter, their behavioral performance was assessed using Morris water maze (MWM) and passive avoidance (PA) tasks. Notably, 30 min before conducting the tasks, scopolamine was injected. Finally, the biochemical assessments were done using the brain tissue. The extract characterization was performed by liquid chromatography-mass spectrometry, which confirmed the presence of quercetin, myricetin, kaempferol, catechin, ellagic acid, and gallic acid derivatives. In the MWM test, the extract reduced both escape latency and the travelled distance, compared to the scopolamine group. Moreover, in the PA test, the latency to enter the dark chamber significantly increased by the extract, compared to the scopolamine group (p < 0.05-p < 0.001). Notably, the beneficial effects of S. minor on cognitive performance of the scopolamine-treated rats appeared to be similar or even better than rivastigmine in behavior performance. Similar to rivastigmine, it was observed that the extract attenuated both AChE activity and oxidative injury in the brain as evidenced by the increased antioxidant enzymes and total thiol content; however, it decreased malondialdehyde level (p < 0.05-p < 0.001). In conclusion, the results suggested the effectiveness of S. minor in preventing cognitive dysfunction induced by scopolamine. Accordingly, these protective effects might be produced by the regulation of cholinergic activity and oxidative stress. S. minor could be considered as a potential alternative therapy in cognition disorders.

Protective Effects of Two Halophilic Crude Extracts from Pseudomonas zhaodongensis and Bacillus stratosphericus against Memory Deficits and Anxiety- and Depression-Like Behaviors in Methionine-Induced Schizophrenia in Mice Focusing on Oxidative Stress Status

Recently, the implication of oxidative stress in behavioral-like disorders has received a lot of attention. Many studies were interested in searching for new natural compounds with protective effects on behavioral-like disorders by focusing on oxidative stress as the main causal factor. Here, we assess the potential effect of cell-free extracts from halophilic bacteria on memory, anxiety, and depression-related behaviors in mice, as well as on cognitive deficits, negative symptoms, and some oxidative stress biomarkers in methionine-induced mice models of schizophrenia. Firstly, crude extracts of bacteria isolated from the Dead Sea were screened for their effects on memory and anxiety- and depression-like behaviors through Y-maze, elevated plus maze, and forced swimming test, respectively, using two doses 60 mg/kg and 120 mg/kg. Then, 120 mg/kg of two bacterial crude extracts, from two strains designated SL22 and BM20 and identified as Bacillus stratosphericus and Pseudomonas zhaodongensis, respectively, with significant contents of phenolic and flavonoid-like compounds, were selected for the assessment of cognitive and negative symptom improvement, as well as for their effects on oxidative stress status in methionine-induced mice models of schizophrenia using six groups (controls, methionine, crude extracts solely, and combinations of crude extracts and methionine). Results showed that the administration of the crude extracts caused a significant increase in the spontaneous alternations in the Y-maze task, the time spent in open arms of the elevated plus maze, and a decrease in immobility time in the forced swimming test in comparison with the control group. Furthermore, the administration of bacterial extracts seemed to diminish disorders related to cognitive and negative symptoms of schizophrenia and to improve the oxidative state in the temporal lobes, in comparison with the methionine group. Our findings suggest substantial antioxidant and anti-neuropsychiatric effects of the crude extracts prepared from Pseudomonas zhaodongensis strain BM20 and Bacillus stratosphericus strain SL22 and that further studies are needed to purify and to determine the active fraction from the extracts.

Ethanolic Extract of Orthosiphon stamineus Improves Memory in Scopolamine-Induced Amnesia Model

Alzheimer’s disease (AD) is a chronic neurodegenerative brain disease which is characterized by impairment in cognitive functioning. Orthosiphon stamineus (OS) Benth. (Lamiaceae) is a medicinal plant found around Southeast Asia that has been employed as treatments for various diseases. OS extract contains many active compounds that have been shown to possess various pharmacological properties whereby in vitro studies have demonstrated neuroprotective as well as cholinesterase inhibitory effects. This study, therefore aimed at determining whether this Malaysian plant derived flavonoid can reverse scopolamine induced learning and memory dysfunction in the novel object recognition (NOR) test and the elevated plus maze (EPM) test. In the present study, rats were treated once daily with OS 50 mg/kg, 100 mg/kg, 200 mg/kg and donepezil 1 mg/kg via oral dosing and were given intraperitoneal (ip) injection of scopolamine 1 mg/kg daily to induce cognitive deficits. Rats were subjected to behavioral analysis to assess learning and memory functions and hippocampal tissues were extracted for gene expression and immunohistochemistry studies. All the three doses demonstrated improved scopolamine-induced impairment by showing shortened transfer latency as well as the higher inflexion ratio when compared to the negative control group. OS extract also exhibited memory-enhancing activity against chronic scopolamine-induced memory deficits in the long-term memory novel object recognition performance as indicated by an increase in the recognition index. OS extract was observed to have modulated the mRNA expression of CREB1, BDNF, and TRKB genes and pretreatment with OS extract were observed to have increased the immature neurons against hippocampal neurogenesis suppressed by scopolamine, which was confirmed by the DCX-positive stained cells. These research findings suggest that the OS ethanolic extract demonstrated an improving effect on memory and hence could serve as a potential therapeutic target for the treatment of neurodegenerative diseases like AD.

Neuropharmacological Potential and Delivery Prospects of Thymoquinone for Neurological Disorders

Thymoquinone (TQ) is an active ingredient isolated from Nigella sativa and has various pharmacological activities, such as protection against oxidative stress, inflammation, and infections. In addition, it might be a potential neuropharmacological agent because it exhibits versatile potential for attenuating neurological impairments. It features greater beneficial effects in toxin-induced neuroinflammation and neurotoxicity. In various models of neurological disorders, it demonstrates emergent functions, including safeguarding various neurodegenerative diseases and other neurological diseases, such as stroke, schizophrenia, and epilepsy. TQ also has potential effects in trauma mediating and chemical-, radiation-, and drug-induced central nervous system injuries. Considering the pharmacokinetic limitations, research has concentrated on different TQ novel formulations and delivery systems. Here, we visualize the neuropharmacological potential, challenges, and delivery prospects of TQ, specifically focusing on neurological disorders along with its chemistry, pharmacokinetics, and toxicity.

Fish oil and wheat germ oil supplementation modulates brain injury in streptozotocin-induced diabetic rats

BACKGROUND

Uncontrolled diabetes mellitus causes neuronal damage because of increased intracellular glucose. Natural products as complementary therapy may reduce neuronal complications. This study investigated whether fish oil (FO) and wheat germ oil (WGO) supplementation protects the brain in streptozotocin (STZ)-induced diabetic rats by estimating lipid peroxidation and the inflammatory and anti-oxidant status of the brain.

METHODS

Diabetes was induced in male Wistar rats by a single i.p. injection of STZ (60 mg/kg). Four weeks after diabetes induction, rats were divided into an untreated group and a group supplemented with 0.4 g/kg per day FO +WGO mix, p.o., for 4 weeks. Brain oxidant status was assessed by measuring nitric oxide (NO), malondialdehyde (MDA), reduced glutathione (GSH), the GSH/oxidized glutathione (GSSG) ratio, and superoxide dismutase (SOD) and catalase (CAT) activity. Inflammatory biomarkers (tumor necrosis factor [TNF]-α levels and nuclear factor (NF)-κβ immunoreaction) were measured in brains, combined with histological studies. Cholinergic function was assessed on the basis of acetylcholine (ACh) levels and acetylcholinesterase (AChE) activity.

RESULTS

Supplementation with FO + WGO reduced MDA and NO ( P  < 0.001) in diabetic rat brains and enhanced brain antioxidant capacity, as evidenced by increased GSH, GSH/GSSG ratio ( P  < 0.01), and SOD and CAT activity ( P  < 0.01). In addition, FO + WGO supplementation suppressed NF-κB immunoreaction and TNF-α levels ( P  < 0.001). Cholinergic function was improved by FO + WGO as a result of increased ACh levels and reduced AChE activity ( P  < 0.001).

CONCLUSIONS

Supplementation of the diet with the FO + WGO mix modulated diabetic brain injury and this mix could potentially be used for preventing diabetic neurodegenerative sequelae.

The effects of Nigella sativa extract on hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats

OBJECTIVES

It has been shown that hypothyroidism-induced oxidative damage in brain tissue is involved in its adverse effects on learning and memory. Nigella sativa (N. sativa) has been suggested to have antioxidant and neuroprotective effects. The objective of this study was to investigate the effects of hydroalcoholic extract of N. sativa on hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats.

METHODS

Thirty pregnant rats were kept in separate cages. After delivery, the mothers and their offspring were randomly divided into six groups including: (1) control, (2) PTU (propylthiouracil), (3) PTU-NS 100, (4) PTU-NS 200, (5) PTU-NS 400, and (6) PTU-Vit C (vitamin C). All dams except the control group received 0.005% PTU in their drinking water during lactation. Besides PTU, dams in groups 3, 4, 5, and 6 received 100, 200, and 400 mg/kg N. sativa extract, or 100 mg/kg Vit C, respectively. After lactation period, pups continued to receive same experimental treatment for the first 8 weeks of their life. Then, 10 male offspring of each group were randomly selected and assessed for the learning and memory abilities by using Morris water maze (MWM) and passive avoidance (PA) tests. Blood samples were collected for thyroxine assessment, animals were euthanized, and the brain tissues were removed and analyzed for total thiol groups and malondialdehyde (MDA) concentrations.

RESULTS

PTU exposure significantly increased the time latency in MWM test, while reduced the time spent in target quadrant, and decreased the latency for entering the dark compartment in PA test. These effects were associated with significant reduction in serum thyroxine levels and brain levels of thiol groups, and significant elevation in hippocampal MDA. Administration of 400 mg/kg N. sativa extract and 100 mg/kg Vit C reduced the time latency, while increased the time spent in target quadrant compared to the PTU group in MWM test. Treatment by 100-400 mg/kg of N. sativa extract and also Vit C significantly increased the time latency for entering the dark compartment in PA test. The serum thyroxine concentrations of the animals treated by all doses of the N. sativa extract as well as by Vit C were higher than that of the PTU group. Two hundred and four hundred milligrams/kilogram of NS extract and 100 mg/kg Vit C decreased the MDA concentration in hippocampal tissues, while increased thiol contents compared to the PTU group.

DISCUSSION

The results of this study demonstrate that the hydroalcoholic extract of N. sativa have protective effects on hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats. The effects were comparable to Vit C and might be due to the protective effects of N. sativa extract against brain tissues' oxidative damage.

Feeding of Nigella sativa during neonatal and juvenile growth improves learning and memory of rats

The positive roles of antioxidants on brain development and learning and memory have been suggested. Nigella sativa (NS) has been suggested to have antioxidant and neuroprotective effects. This study was done to investigate the effects of feeding by the hydro-alcoholic extract of NS during neonatal and juvenile growth on learning and memory of rats. The pregnant rats were kept in separate cages. After delivery, they were randomly divided into four Groups including: (1) control; (2) NS 100 mg/kg (NS 100); (3) NS 200 mg/kg (NS 200); and (4) NS 400 mg/kg (NS 400). Rats in the control group (Group 1) received normal drinking water, whereas Groups 2, 3, and 4 received the same drinking water supplemented with the hydro-alcoholic extract of NS (100 mg/kg, 200 mg/kg, and 400 mg/kg, respectively) from the 1st day after birth through the first 8 weeks of life. After 8 weeks, 10 male offspring from each group were randomly selected and tested in the Morris water maze (MWM) and passive avoidance (PA) test. Finally, the brains were removed and total thiol groups and malondialdehyde (MDA) concentrations were determined. In the MWM, treatment by 400 mg/kg extract reduced both the time latency and the distance traveled to reach the platform compared to the control group (p < 0.05-p < 0.01). Both 200 mg/kg and 400 mg/kg of the extract increased the time spent in the target quadrant (p < 0.05-p < 0.01). In the PA test, the treatment of the animals by 200 mg/kg and 400 mg/kg of NS extract significantly increased the time latency for entering the dark compartment (p < 0.05-p < 0.001). Pretreatment of the animals with 400 mg/kg of NS extract decreased the MDA concentration in hippocampal tissues whereas it increased the thiol content compared to the control group (p < 0.001). These results allow us to propose that feeding of the rats by the hydro-alcoholic extract of NS during neonatal and juvenile growth has positive effects on learning and memory. The effects might be due to the antioxidant effects.

The Role of Nigella sativa and Its Active Constituents in Learning and Memory

The loss of the ability for learning and memory is a prominent feature of dementia, which affects millions of individuals all over the world, due to either neurodegenerative diseases or brain injury. Although a lot of information is known about the pathology involved, treatment remains elusive at best. The Black Seed of Nigella sativa has been historically and religiously used for thousands of years for preventing and treating many different kinds of diseases. This review article looks at Nigella sativa and its potential role in facilitating learning and memory. The possible use of this seed's extract or compounds isolated from it, such as thymoquinone, for treating damaged brain neural tissue is discussed. The evidence presented in this paper appears to be supporting the hypothesis that this plant and/or its bioactive constituents can enhance learning and memory in health and disease in animals and humans.

Emilia coccinae (SIMS) G Extract improves memory impairment, cholinergic dysfunction, and oxidative stress damage in scopolamine-treated rats

BACKGROUND

E. coccinae (SIMS) G. (Asteraceae) is an annual plant commonly found throughout the plain of the Central Africa and widely used in Cameroonian folk medicine for the treatment of fever and convulsions in children. We previously reported that the methanolic extract of this plant improved spatial memory. However no underlying mechanism was explored. The present study was undertaken to investigate the effects of the hydroalcoholic extract of Emilia coccinae on memory in scopolamine treated rats and to propose possible mechanisms of action.

METHODS

Novel object recognition and Y-maze paradigm were used to test memory while oxidative profile, AChE and ACh level of the whole brain were assessed to outline the mechanism of nootropic activity of the extract. 200 and 400 mg/kg of the extract were chronically administrated during 14 consecutive days in separate groups of scopolamine intraperitoneal treated rats (1.5 mg/kg).

RESULTS

The hydroalcoholic extract of Emilia coccinae (HEEC) at the dose of 200 mg/kg significantly improved the memory of rats and reversed the amnesia induced by scopolamine. In addition, we showed that this extract is decreasing the acetyl cholinesterase activity while also increasing the acetylcholine levels in the brain. HEEC (200 and 400 mg/kg) significantly increased antioxidant enzyme activities (SOD, GSH and CAT) and reduced lipid peroxidation (MDA level) in the rat whole brain homogenates.

CONCLUSIONS

Taken together, our results suggested that the hydroalcoholic extract of Emilia coccinae ameliorated the cognitive dysfunction in scopolamine treated rats through the blockage of the oxidative effect of scopolamine and inhibition of AChE activity.

Nigella sativa Oil Enhances the Spatial Working Memory Performance of Rats on a Radial Arm Maze

Nigella sativa, an established historical and religion-based remedy for a wide range of health problems, is a herbal medicine known to have antioxidant and neuroprotective effects. This present study investigated the effect of Nigella sativa oil (NSO) administration on the spatial memory performance (SMP) of male adult rats using eight-arm radial arm maze (RAM). Twelve Sprague Dawley rats (7–9 weeks old) were force-fed daily with 6.0 μL/100 g body weight of Nigella sativa oil (NSO group; n = 6) or 0.1 mL/100 g body weight of corn oil (control) (CO group; n = 6) for a period of 20 consecutive weeks. For each weekly evaluation of SMP, one day food-deprived rats were tested by allowing each of them 3 minutes to explore the RAM for food as their rewards. Similar to the control group, the SMP of the treated group was not hindered, as indicated by the establishment of the reference and working memory components of the spatial memory. The results demonstrated that lesser mean numbers of error were observed for the NSO-treated group in both parameters as compared to the CO-treated group. NSO could therefore enhance the learning and memory abilities of the rats; there was a significant decrease in the overall mean number of working memory error (WME) in the NSO-treated group.