Neurochemical and behavioral effects of Nigella sativa and Olea

Nutritional Neuroscience An International Journal on Nutrition, Diet and Nervous System

ISSN: 1028-415X (Print) 1476-8305 (Online) Journal homepage: http://www.tandfonline.com/loi/ynns20

Neurochemical and behavioral effects of Nigella sativa and Olea europaea oil in rats M. Atif Raza Cheema, Shazia Nawaz, Sumera Gul, Tabinda Salman, Sabira Naqvi, Ahsana Dar & Darakhshan J. Haleem To cite this article: M. Atif Raza Cheema, Shazia Nawaz, Sumera Gul, Tabinda Salman, Sabira Naqvi, Ahsana Dar & Darakhshan J. Haleem (2018) Neurochemical and behavioral effects of Nigella sativa and Olea europaea oil in rats, Nutritional Neuroscience, 21:3, 185-194, DOI: 10.1080/1028415X.2016.1257417 To link to this article: https://doi.org/10.1080/1028415X.2016.1257417

Published online: 21 Nov 2016.

Submit your article to this journal

Article views: 93

View related articles

View Crossmark data

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ynns20

Neurochemical and behavioral effects of Nigella sativa and Olea europaea oil in rats M. Atif Raza Cheema 1, Shazia Nawaz 1, Sumera Gul1, Tabinda Salman 1, Sabira Naqvi2, Ahsana Dar2, Darakhshan J. Haleem 1 1

Neuroscience Research Lab, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan, 2Pharmacology Section, HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan Objectives: In the last few decades, therapeutic uses of medicinal compounds present in food as a normal constituent has risen substantially, largely because of their fewer side effects and adequate efficacy. This study is designed to investigate a role of brain serotonin (5-HT) and dopamine (DA) in the potential nootropic, anxiolytic, and other beneficial effects of Nigella sativa (NS) and Olea europaea (OE) oil in rat models. Methods: Animals were treated with NS and OE oil orally at doses of 0.1 ml/kg and 0.25 ml/kg for 5 weeks. Food intake and body weight change, anxiety-like effects in elevated plus maze and activity in a novel and familiar environment were monitored weekly. Effects on learning and memory after 5 weeks treatment were monitored using Morris water maze test. Neurochemical analysis was carried using HPLC-ECD method. Results: NS and OE oil administration enhanced learning and memory in Morris water maze test and the effects were greater in NS than OE oil-treated animals. Low dose of OE oil increased exploration in an open field, higher dose of OE oil and both doses of NS oil produced no consistent effect on open field exploration. Effects of both oils on anxiety-like behavior, food and water intake, and activity in activity box were either not consistent or did not occur. The treatment increased homovanillic acid (HVA). 5-HT levels increased in high dose of NS oil and low dose of OE oil-treated groups. Low dose NS oil decreased 5-HT. Discussion: The present study suggests that active components in NS and OE oil may prove useful in treating impaired cognition. OE oil may produce psychostimulant-like effect. Modulation of DA and serotonin neurotransmission seems important in the pharmacological effect of these oils.

Keywords: Nigella sativa, Olea europaea, Anxiety, Learning, Memory, Motor activity, Dopamine, Serotonin

Introduction In the last few decades, therapeutic uses of medicinal compounds present in food as a normal constituent has risen substantially. It is largely because of their fewer side effects and adequate efficacy. There is growing need of drugs to improve cognition because the currently available drugs for improving cognition such as psychostimulants not only have abuse potential but also produce psychosis.1 Treatments for stress-related disorders such as anxiety and depression are also not adequate and remission rate are not satisfactory.2 In this context, there is growing interest in the use of traditional natural compounds for treating anxiety and improving cognition.

Correspondence to: M. A. R. Cheema, Neuroscience Research Lab, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan. Email: [email protected]

© 2016 Informa UK Limited, trading as Taylor & Francis Group DOI 10.1080/1028415X.2016.1257417

Nigella sativa L. (NS) is a medicinal plant (family: Ranunculaceae) commonly known as Black cumin or Black seed. The seeds of NS have been traditionally used for the treatment of diabetes, bronchial asthma, hypertension, and other diseases.3–5 The oil and extracts of NS have been shown to produce neuroprotective, anticonvulsant, analgesic, anti-inflammatory, and anticancer effects.6–10 Olea europaea L. (OE) (family: Oleaceae) is commonly called olive. The oil of OE has been used in folk medicine due to its cardioprotective and antihypertensive effects.11 It has been also shown to have neuroprotective, analgesic, anti-inflammatory, and anticancer properties.12 Despite a number of acceptable beneficial effects and reported antioxidant effects,13–15 only few studies have been performed on the effects of NS and OE oil for improving cognition.16–18 Moreover, the effects of these oils on brain monoamine

Nutritional Neuroscience

2018

VOL.

21

NO.

3

185

Cheema et al.

Neurochemical and behavioral effects of NS and OE oil in rats

metabolism have not been reported. We performed a comprehensive study on the long term effects of NS and OE oil on food intake and body weight change, anxiety-like effects in elevated plus maze and activity in a novel and familiar environment. Effects on learning and memory are also monitored using Morris water maze test. In view of a role of brain 5-HT and DA in these behaviors, associated effects on brain monoamine metabolism are also determined.

Methods Animals Male Wistar rats, weighing 180–230 g were obtained from Animal Research Facility of Dr Panjwani Center for Molecular Medicine and Drug Research. These animals were housed individually under standard conditions of temperature (22 ± 2°C) and humidity (55 ± 10%) with 12-h light/dark cycle. They were provided standard rodent food and water ad libitum during the entire study period. Animal handling and study protocol was conducted in accordance with international guidelines for ethical care and use of animals for research, which included the National Institute of Health Guidelines for Care and Use of Laboratory Animals. This study was approved by Institutional Animal Care and Use Committee, International Center for Chemical and Biological Sciences, University of Karachi.

Monitoring food and water intakes and body weights Each animal was provided with pre-weighed food in the hopper of the cage. Cumulative food intake (g) was monitored between 08:30 and 09:30 h by weighing the food left in the hopper and is reported as cumulative 5 weeks intake. Tap water was filled in the feeding bottles of each animal. Cumulative water intake (ml) was also monitored between 08:30 and 09:30 h by measuring the water left in the bottles and is reported as cumulative 5 weeks water intake. Percentage change in body weight was calculated as: (body weight after 5 weeks treatment/body weight before treatment) × 100 as reported earlier.19

Chemicals and reagents

Activity in an activity box

Mature dried seeds of NS procured from a specialized local herbal store of Karachi were identified and authenticated by Dr Anjum Perveen, Director, Centre for Plant Conservation, University of Karachi (G.H. No. 90080), Karachi (Pakistan). Crude oil of NS was extracted by pressing whole seeds according to AlOkbi et al, (2013). OE oil (100% pure) was purchased from a local market ( packed by Sasso® via L. Da Vinci, 31 Tavarnelle Val di Pesa (Firenze) Italy). 5-hydroxyindole acetic acid (5-HIAA), dihydroxyphenyl acetic acid (DOPAC), dopamine (DA), homovanillic acid (HVA), serotonin (5-hydroxytryptamine, 5-HT), and sodium octyl sulfate (SOS) were procured from Sigma (St. Louis, Mo, USA). All chemicals and reagents used in HPLC were of HPLC grade. While all other chemicals and reagents were also of highest purity grade.

Activity in the familiar environment of activity box was monitored as described before.20 Specially designed transparent activity cages with a small area (26 × 26 × 26 cm) with sawdust-covered floor were used. The experiment was conducted in a quiet room. The animals were placed in the activity box 10 minutes before monitoring activity test and number of cage crossing counted for another 10 minutes. Activity box was carefully cleaned with an ethanolsoaked cloth after removal of each rat. Water-, NS-, and OE oil-treated rats were tested in a balanced design to avoid order effect.

Experimental protocol Thirty five rats were randomly divided in to five groups: (i) Water (0.1 ml/kg), (ii) NS oil 10 (0.1 ml/ kg), (iii) NS oil 25 (0.25 ml/kg), (iv) OE oil 10 (0.1 ml/kg), and (v) OE oil 25 (0.25 ml/kg) each containing seven animals. NS and OE oil were administered orally at 09:30 to 10:00 h daily for 5 weeks. Control animals received water by the same route.

186

Change in body weight gain, cumulative food and water intake during 5 weeks treatment were monitored. Activity in an activity box and open field were monitored weekly from 10:30 to 11:00 h and 11:30 to 12:00 h, respectively. Performance in elevated plus maze test was also conducted weekly from 12:30 to 13:00 h. After 5 weeks of treatment animals were trained in Morris water maze from 10:30 to 11:30 h. Learning acquisition was monitored 2 h after training from 12:30 to 13:30 h. The retention of memory was assessed next day from 09:00 to 10:00 h. Afterwards animals were decapitated at 11:00 to 12:00 h to collect brain samples. Which were stored at −80°C for neurochemical analysis by HPLC-ECD.


2018

VOL.

21

NO.

3

Activity in an open field The procedure was essentially same as reported previously.21, 22 The open field consisted of a square area (76 × 76 cm) with opaque walls of 42 cm height. Floor of this apparatus was divided by lines into 25 squares of equal size (15 cm). To monitor activity, a rat was placed in the center sqaure of the open field, immediately after which number of squares crossed with all four paws were counted for a period of 5 minutes. Open field was carefully cleaned with an ethanol-soaked cloth after removal of each animal. Water- and oil-treated rats were tested in a balanced design to avoid order effect.

Cheema et al.

Elevated plus maze Elevated plus maze test was used to monitor anxietylike behavior of water- and oils-treated rats as reported earlier.23 The maze was made up of white acrylic with 50 cm long and 10 cm wide four arms arranged in shape of a ‘plus’ sign and elevated (60 cm) from the floor. Two arms of the maze had no sides or end walls ‘ the open arms’, the other two arms ‘the closed arms’ had 15 cm high side and end walls but were open at the top. A central area (10 cm × 10 cm) of square platform at the intersection of open and closed arms provided access to all arms. To monitor elevated plus maze activity, a rat was placed in the central area facing the corner between a closed and an open arm. The rat was allowed to explore the open and closed arms and time spent in the open arm was monitored for total period of 5 minutes exposure to the elevated plus maze. Elevated plus maze apparatus was carefully cleaned with a damp cloth after removal of each animal. Water- and oil-treated animals were tested in a balanced design to avoid order effect.

Morris water maze The apparatus for water maze test consisted of a white circular pool made up of plastic with a diameter of 90 cm and height of 37 cm and a white rigid square platform (10 × 10 cm2).24 The pool was filled with water (24 ± 2°C) to depth of 30 cm and rendered opaque by the addition of a small quantity of pure milk. Escape from the water was provided by means of a hidden platform which was typically submerged 2 cm below the water surface in a fixed location (north quardrant). Water maze was positioned in a room surrounded by local visual cues (cabinets, window, equipments, etc.) which remained invariant with the maze during the entire experiment. The pool area was arbitrarily divided into four equal quadrants: North (N), South (S), East (E), and West (W). In the training session, each animal was given a series of three trials using three different start position, one from each quadrant (other than the one containing the platform). The inter-trial interval was 60 s. During each trial, rat was placed in the maze, facing the pool wall and given a standard trial limit of 120 s to find and mount onto the platform. If the rat succeeded it was allowed to stay on the platform for 10 s. If an animal failed to find the platform within the time limit, it was guided gently on the platform. After a trial, rats were placed in a cage and dried with towels. In the test phase, animals were tested for learning acquisition and memory retention by placing the rat in the S quadrant and monitoring latency time to reach the hidden platform. Learning acquisition was monitored after 2 hours of the training between


12:30 and 13:30 h. While memory retention was assessed next day between 09:00 and 10:00 h.

Neurochemical analysis Biogenic amines: i.e., 5-HT and DA, as well as their metabolites, 5-HIAA, DOPAC, and HVA were estimated in the whole brain by HPLC-ECD (High Performance Liquid Chromatography with Electrochemical Detector) as previously reported.20,25 Aliquots of 20 μL of sample were injected on the top of the column via auto-sampler/injector. Biogenic amines and their metabolites were detected in a single sample by reversed phase HPLC with LEC 6A electrochemical detector (Shimadzu, Kyoto, Japan) at an operating potential of + 0.8 to + 1.0 V. Message from the detector was recorded by computer software (Shimadzu’s LCsolution). Each component of sample was identified and quantified by comparing its retention time and area under the peak with that of the standard. A commercially available 5 μm separation column of 0.6 mm internal diameter and 250 mm length packed with C-18 Octadecylsilane (ODS) (Schimadzu CLC-ODS) was used as the stationary phase. Separation was achieved by a mobile phase (containing methanol (14%), sodium octyl sulfate (SOS) (0.023%), and EDTA (0.005%) in 0.1 M sodium phosphate buffer at pH 2.9) at operating pressure of 2000–3000 psi on electrochemical detector.

Statistical analysis Effects of treatment on food and water intakes, body weights, and serotonin and DA metabolism were analyzed by one-way ANOVA. Effects on activity, elevated plus maze and Morris water maze performance, monitored weekly, were analyzed by two-way ANOVA (repeated measure design). IBM SPSS Statistics version 19 was used for the statistical analysis. Post hoc comparison were made by Tukey’s test. P values 0.05), water intake (F = 1.900; df = 4, 30 P > 0.05), and body weight (F = 2.157; df = 4, 30 P > 0.05) were not significant.

Effects on activity and elevated plus maze performance Figure 2 shows effects of treatment on activity in activity box, open field, and elevated plus maze performance. Analysis of the data on activity in activity


2018

VOL.

21

NO.

3

187

Cheema et al.


Figure 1 Effects of repeated administration of NS and OE oil (0.1 and 0.25 ml/kg) for 5 weeks on cumulative food and water intake and body weight change. Values are means ± SD (n = 7). Differences between groups by one-way ANOVA were not significant.

box (Fig. 2A) by two-way ANOVA (repeated measure design) showed significant repeated measure (weeks) (F = 4.764; df = 4, 30 P < 0.01) and treatment (F = 7.950; df = 4, 30 P < 0.01) effects. Interaction between weeks and treatment (F = 4.297; df = 16, 30 P < 0.01) was also significant. Data on open field activity (Fig. 2B) showed significant effects of weeks

188


2018

VOL.

21

NO.

3

(F = 18.499; df = 4, 30 P < 0.01) and treatment (F = 53.162; df = 4, 30 P < 0.01). Interaction between weeks and treatment (F = 3.556; df = 16, 30 P < 0.01) was also significant. Data on elevated plus maze activity (Fig. 2C) also showed significant effects of weeks (F = 4.055; df = 4, 30 P < 0.01) and treatment (F = 6.040; df = 4, 30 P < 0.01) and a

Cheema et al.


Figure 2 Effects of repeated administration of NS and OE oil (0.1 and 0.25 ml/kg/day) for 5 weeks on weekly changes of activity in activity box, open field, and elevated plus maze performance. Values are means ± SD (n = 7). Significant differences by Tukey’s test: *P < 0.05, **P < 0.01, +P < 0.01 from respective water or week1 rats following two-way ANOVA (repeated measure design).

significant interaction between weeks and treatment (F = 6.598; df = 16, 30 P < 0.01). Post hoc analysis by Tukey’s test showed that 5 weeks administration of higher doses of both NS and

OE oil decreased motor activity in the activity box. Animals treated with higher dose of NS oil for 3 weeks also exhibited a decrease in motor behavior. Conversely, animals treated with lower dose of NS


2018

VOL.

21

NO.

3

189

Cheema et al.


oil for 4 weeks exhibited an increase in activity. Other differences were not significant. Exploratory activity in an open field was also enhanced in animals treated with lower dose of NS for 2 and 3 weeks. A consistent increase in open field exploration occurred in rats treated with lower dose of OE oil for 1, 2, 3, 4, and 5 weeks. The results, in general, tend to show that higher doses of NS as well as OE oil administered for 5 weeks decrease motor behavior in the familiar environment of activity box, while lower dose of OE oil administered for 1 week increases exploratory activity in the novel arena of open field which persisted till 5 weeks treatment. Moreover, repeated monitoring resulted in a decrease in exploratory activity in water treated animals after 1 week which persisted till 5 weeks treatment, suggesting habituation effect. These habituation effects delayed in low dose NS oiltreated animals; did not appear in high dose NS oiltreated animals. The high dose olive oil-treated animals also exhibited habituation effects but these were less apparent in low dose OE oil-treated animals. The results tend to suggest modulation of habituation due to motor effect of the oils.

Effects of treatment on elevated plus maze performance were largely not significant over 5 weeks treatment. An increase in time spent in open arm showing anxiolytic-like effect of low dose of NS oil in rats treated for 1 week did not occur after 2–5 weeks treatment. Lower dose of OE oil-treated animals exhibited anxiolytic effect after 5 weeks treatment, effects after 1–4 weeks treatment were not significant.

Morris water maze Figure 3 shows effects of the treatment on water maze performance. Analysis of the data by two-way ANOVA (repeated measure design) showed that effects of repeated measure (F = 12.693; df = 1, 30 P < 0.01), treatment (F = 17.966; df = 4, 30 P < 0.01), and interaction between repeated measure and treatment (F = 12.881; df = 4, 30 P < 0.01) were significant. Post hoc analysis by Tukey’s test showed that administration of higher dose of NS oil improved learning acquisition. Effects of OE oil and lower dose of NS oil were not significant. Memory retention was

Figure 3 Effects of repeated administration of NS and OE oil (0.1 and 0.25 ml/kg) for 5 weeks on learning acquisition and memory retention. Values are means ± SD (n = 7). Significant differences by Tukey’s test: *P < 0.01 following two-way ANOVA (repeated measure design).

190


2018

VOL.

21

NO.

3

Cheema et al.

improved in rats treated with both doses of NS oil and lower but not higher dose of OE oil.

Neurochemical analysis Figure 4 shows effects of treatment on DA metabolism. Analysis of the data by one-way ANOVA showed that effects of treatment (df = 4, 30) were significant for DOPAC (F = 3.218; P < 0.05), DA (F =


3.110; P < 0.05), and HVA (F = 46.726; P < 0.01). Post hoc analysis by Tukey’s test showed that administration of both low and high dose of NS and OE oil increased HVA levels. Administration of both oils had no effect on DA and DOPAC levels. Figure 5 shows effects of treatment on serotonin metabolism. Analysis of the data by one-way ANOVA showed that effects of treatment (df = 4, 30)

Figure 4 Effects of administration of NS and OE oil (0.1 and 0.25 ml/kg) for 5 weeks on DA metabolism. Values are means ± SD (n = 7). Significant differences by Tukey’s test: *P < 0.05, **P < 0.01, following one-way ANOVA.


2018

VOL.

21

NO.

3

191

Cheema et al.


Figure 5 Effects of administration of NS and OE oil (0.1 and 0.25 ml/kg) for 5 weeks on serotonin metabolism. Values are means ± SD (n = 7). Significant differences by Tukey’s test: *P < 0.05, **P < 0.01, following one-way ANOVA.

were significant for 5-HT (F = 14.210; P < 0.01) but not for 5-HIAA (F = 1.371; P > 0.05). Post hoc analysis by Tukey’s test showed that administration of higher dose of NS oil and lower dose of OE oil increased while lower dose of NS oil decreased 5-HT levels. Higher dose of OE oil did not alter the 5-HT levels.

Discussion The present study was designed to monitor effects of long term administration of NS and OE oil on brain DA and serotonin metabolism and to relate it with their potential effects on anxiety and memory. A consistent finding of the present study is an increase in HVA concentration by both NS and OE oils. Serotonin levels decreased and increased respectively by low and high doses of NS oil. The OE oil treatment increased serotonin but the increases were not significant at higher dose. Both of these oils improved performance in water maze but the effect was not significant in higher dose OE oil-treated animals. Moreover, animals treated with low dose OE oil also exhibited an increase in exploratory activity in an open field. The results suggest a potential nootropic

192


2018

VOL.

21

NO.

3

effect of active components present in NS and OE oil, and a role of DA as well as serotonin in these effects (Table 1). Other authors have reported that hydro-alcoholic extract of NS26 or feeding NS during neonatal and juvenile growth,27 improves learning and memory of rats. Long term oral administration of NS oil also improved performance in Morris water maze17 as the animals exhibited better performance than corn oiltreated animals. That long term administration of olive oil improves performance in object recognition task and T-maze test in mice has also been shown.16 We report improved performance in Morris water maze test in rats treated with very low doses of NS as well as OE oil to suggest that long term intake of these oils can improve cognitive performance. We also show that the nootropic effects of NS oil are greater than OE oil (Fig. 3). The nootropic effects of NS as well as OE are often explained in terms of potent antioxidant properties of active components.16,27 This is the first study to relate nootropic effects of NS and OE oil with brain DA and serotonin. A consistent increase in HVA concentration in all treated groups despite no effect on DA and

Cheema et al.


Table 1 Neurochemical and behavioral effects of NS and OE oil NS oil

OE Oil

Parameter

Low dose (0.1 ml/kg)

High dose (0.25 ml/kg)

Low dose (0.1 ml/kg)

High dose (0.25 ml/kg)

Food intake Water intake Body weight Activity in an activity box Open field Elevated plus maze Learning acquisition Memory retention DOPAC DA 5-HIAA HVA 5-HT

– – – ↑ ↑ ↑ – ↑ – – – ↑ ↓

↓* – – ↓ – ↓ ↑ ↑ – – – ↑ ↑

– – – – ↑ ↑ – ↑ – – – ↑ ↑

– – – ↓ – – – – – – – ↑ –

Key: *(P = 0.06); ↑ = increase in response; ↓ = decrease in response; – = no response; 5-HIAA = 5-hydroxyindoleacetic acid; 5-HT = serotonin; DA = dopamine; DOPAC = 3,4-dihydroxyphenylacetic acid; HVA = homovanillic acid.

DOPAC concentration can be explained in terms of greater DA metabolism and/or neurotransmission (Fig. 4). We suggest that these oils produce a moderate facilitatory effect on DA neurotransmission to improve cognitive performance. Previously, it has been shown that rats treated with NS oil in doses of 0.4 ml/kg for 4 weeks exhibited an increase in open field exploration, and reduced anxiety level, which was associated with an increase in brain 5-HT but lower 5-HIAA concentration in the brain.28 In the present study, doses much smaller than reported previously were used. We find that oral administration of 0.1 and 0.25 ml/kg NS oil for 5 weeks produces no effect on anxiety level or exploratory activity (Fig. 2B–C). 5-HT levels decrease with lower doses of NS oil while higher doses increase it. The results tend to suggest that low doses of NS and OE oil, though nootropic, have little effect on anxiety level. This is also relevant that a dose-related effect of NS and OE oil is not produced on brain 5HT levels (Fig. 5). That administration of NS oil in doses of 0.1 ml/kg for 4 weeks increases brain 5-HT levels, but 5-HIAA concentration is decreased has been shown previously.29 We find an increase in brain 5-HT concentration in rats treated with 0.25 ml/kg NS oil for 5 weeks. Animals treated with 0.1 ml/kg NS oil exhibited reduced 5-HT levels. The 5-HT levels also increased in rats treated with low dose OE oil (Fig. 5). More dose-related studies are required to establish a potential role of serotonin if any, in the behavioral effects of NS and OE oils. Our finding on an increase in HVA concentration in rats treated with OE oil, though consistent with previous study,30 do not support an anxiolytic-like effect of OE oil. An increase in exploratory activity in an open field, indicative of CNS stimulatory effect1 with lower dose of OE oil (Fig. 2B) is explainable in terms of greater increase in DA metabolism in the rats.

In conclusion, the present study supports therapeutic use of NS and OE oil in improving cognition but not in reducing anxiety. Moreover, this study shows that particularly lower dose of OE increases exploratory activity. The effects of both of these oils on behavior seem to be associated via an increase in DA neurotransmission. Further studies on the effects of higher doses of these oils may help to explain inconsistency in the present and previously reported studies particularly on the effect of these oils on anxiety and serotonin neurotransmission. The present study raises the possibility that active components in NS and OE oil can facilitate DA neurotransmission to produce beneficial effects on cognition.

Acknowledgments The authors would like to thank Dr. Panjwani Center for Molecular Medicine and Drug Research (PCMD), University of Karachi for providing faculty research grants.

Disclaimer statements Contributors M. Atif Raza Cheema performed all the experiments and wrote major part of the manuscript. Shazia Nawaz helped in animal dissection. Sumera Gul helped in statistical analysis. Tabinda Salman helped in animal dissection. Sabira Naqvi helped in HPLC work. Ahsana Dar helped in HPLC work. Darakhshan J. Haleem designed the experiment and supervised the entire research. Funding None. Conflicts of interest None. Ethics approval Animal handling and study protocol was conducted in accordance with international guidelines for ethical care and use of animals for research, which included the National Institute of Health Guidelines for Care and Use of Laboratory Animals. This study was approved by Institutional Animal


2018

VOL.

21

NO.

3

193

Cheema et al.


Care and Use Committee, International Center for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, Pakistan.

ORCID M. Atif Raza Cheema 0710-8554

15

16

http://orcid.org/0000-000217

References 1 Haleem DJ. Extending therapeutic use of psychostimulants: focus on serotonin-1A receptor. Prog Neuro-Psychopharmacol Biol Psychiatry 2013;46:170–80. 2 Masi G, Liboni F, Brovedani P. Pharmacotherapy of major depressive disorder in adolescents. Expert Opin Pharmacother 2010;11(3):375–86. 3 Salem ML. Immunomodulatory and therapeutic properties of the Nigella sativa L. seed. Int Immunopharmacol 2005;5(13– 14):1749–70. 4 Butt MS, Sultan MT. Nigella sativa: reduces the risk of various maladies. Crit Rev Food Sci Nutr 2010;50(7):654–65. 5 Khader M, Eckl PM. Thymoquinone: an emerging natural drug with a wide range of medical applications. Iran J Basic Med Sci 2014;17(12):950–7. 6 Kanter M, Coskun O, Kalayci M, Buyukbas S, Cagavi F. Neuroprotective effects of Nigella sativa on experimental spinal cord injury in rats. Hum Exp Toxicol 2006;25(3):127–33. 7 Ilhan A, Gurel A, Armutcu F, Kamisli S, Iraz M. Antiepileptogenic and antioxidant effects of Nigella sativa oil against pentylenetetrazol-induced kindling in mice. Neuropharmacology 2005;49(4):456–64. 8 Bashir MU, Qureshi HJ. Analgesic effect of Nigella sativa seeds extract on experimentally induced pain in albino mice. J Coll Physicians Surg Pak 2010;20(7):464–7. 9 Bourgou S, Pichette A, Marzouk B, Legault J. Antioxidant, antiinflammatory, anticancer and antibacterial activities of extracts from Nigella sativa (Black cumin) plant parts. J Food Biochem 2012;36(5):539–46. 10 Ait Mbarek L, Ait Mouse H, Elabbadi N, Bensalah M, Gamouh A, Aboufatima R, et al. Anti-tumor properties of blackseed (Nigella sativa L.) extracts. Brazilian J Med Biol Res 2007;40 (6):839–47. 11 Fezai M, Senovilla L, Jemaà M, Ben-Attia M, Ben-Attia M. Analgesic, anti-inflammatory and anticancer activities of extra virgin Olive oil. J Lipids 2013;2013:1–7. 12 González-Correa JA, Muñoz-Marín J, Arrebola MM, Guerrero A, Narbona F, López-Villodres JA, et al. Dietary virgin olive oil reduces oxidative stress and cellular damage in rat brain slices subjected to hypoxia-reoxygenation. Lipids 2007;42(10):921–9. 13 Fitó M, Cladellas M, de la Torre R, Martí J, Alcántara M, Pujadas-Bastardes M, et al. Antioxidant effect of virgin olive oil in patients with stable coronary heart disease: a randomized, crossover, controlled, clinical trial. Atherosclerosis 2005;181(1): 149–58. 14 Erkan N, Ayranci G, Ayranci E. Antioxidant activities of rosemary (Rosmarinus Officinalis L.) extract, blackseed (Nigella sativa L.)

194


2018

VOL.

21

NO.

3

18

19 20 21

22 23 24 25

26

27

28 29

30

essential oil, carnosic acid, rosmarinic acid and sesamol. Food Chem 2008;110(1):76–82. Pitozzi V, Jacomelli M, Zaid M, Luceri C, Bigagli E, Lodovici M, et al. Effects of dietary extra-virgin olive oil on behaviour and brain biochemical parameters in ageing rats. Br J Nutr 2010;103(11):1674–83. Farr SA, Price TO, Dominguez LJ, Motisi A, Saiano F, Niehoff ML, et al. Extra virgin olive oil improves learning and memory in SAMP8 mice. J Alzheimers Dis 2012;28(1):81–92. Sahak MKA, Mohamed AM, Hashim NH, Hasan Adli DS. Nigella sativa oil enhances the spatial working memory performance of rats on a radial arm maze. Evid Based Complement Alternat Med 2013;2013. Article id 180598. Bin Sayeed MS, Asaduzzaman M, Morshed H, Hossain MM, Kadir MF, Rahman MR. The effect of Nigella sativa Linn. seed on memory, attention and cognition in healthy human volunteers. J Ethnopharmacol 2013;148(3):780–6. Haleem DJ, Kennett G, Curzon G. Adaptation of female rats to stress: shift to male pattern by inhibition of corticosterone synthesis. Brain Res 1988;458(2):339–47. Ikram H, Ahmad S, Haleem DJ. Effects of apomorphine on locomotive activity and monoamine metabolism: a dose related study. Pak J Pharm Sci 2011;24(3):315–21. Kennett GA, Dickinson SL, Curzon G. Central serotonergic responses and behavioural adaptation to repeated immobilisation: the effect of the corticosterone synthesis inhibitor metyrapone. Eur J Pharmacol 1985;119(3):143–52. Ikram H, Haleem DJ. Attenuation of apomorphine-induced sensitization by buspirone. Pharmacol Biochem Behav 2011;99(3): 444–50. Haleem DJ, Haque Z, Inam Q-A, Ikram H, Haleem MA. Behavioral, hormonal and central serotonin modulating effects of injected leptin. Peptides 2015;74:1–8. Morris R. Developments of a water-maze procedure for studying spatial learning in the rat. J Neurosci Methods 1984;11(1):47–60. Haleem DJ, Shireen E, Haleem MA. Somatodendritic and postsynaptic serotonin-1A receptors in the attenuation of haloperidol-induced catalepsy. Prog Neuropsychopharmacol Biol Psychiatry 2004;28(8):1323–9. Vafaee F, Hosseini M, Hassanzadeh Z, Edalatmanesh MA, Sadeghnia HR, Seghatoleslam M, et al. The effects of Nigella sativa hydro-alcoholic extract on memory and brain tissues oxidative damage after repeated seizures in rats. Iran J Pharm Res 2015;14(2):547–57. Beheshti F, Hosseini M, Vafaee F, Shafei MN, Soukhtanloo M. Feeding of Nigella sativa during neonatal and juvenile growth improves learning and memory of rats. J Tradit Complement Med 2016;6(2):146–52. Perveen T, Haider S, Kanwal S, Haleem DJ. Repeated administration of Nigella sativa decreases 5-ht turnover and produces anxiolytic effects in rats. Pak J Pharm Sci 2009;22(2):139–44. Perveen T, Haider S, Zuberi NA, Saleem S, Sadaf S, Batool Z. Increased 5-HT levels following repeated administration of Nigella sativa L.(black seed) oil produce antidepressant effects in rats. Sci. Pharm 2014;82:161–170. Perveen T, Hashmi BM, Haider S, Tabassum S, Saleem S, Siddiqui MA. Role of monoaminergic system in the etiology of olive oil induced antidepressant and anxiolytic effects in rats. ISRN Pharmacol 2013;2013. Article id 615685.