Effect Of Vitamins C And E On Memory In Adult Mice
Effect Of Vitamins C And E On Memory In Adult Mice
ABSTRACT
Vitamins C and E are naturally present in some foods and are available as dietary supplements. While vitamin C is also known as L-ascorbic acid, vitamin E is a generic name for tocopherols and tocotrienols each with α, β, γ, and δ subunits.
Neurobehavioural models have been used to study behavior in animals with models specific for each animal species and behavior.
The aim of the study was to investigate the effect of vitamins C and E on memory and serum biochemical changes in adult mice. Twenty male and twenty female mice weighing 16-35 g were divided into 5 groups of eight mice each.
The first group served as the control and received distilled water (1 ml/kg); mice in the second group served as the positive control and received soya oil (1 ml/kg), animals in group three received vitamin C (100 mg/kg), group four received vitamin E (100 mg/kg) and the last group received both vitamins C and E (100 mg/kg).
The drugs were given once daily orally for a period of 21 days. Learning and memory were assessed using the elevated plus maze (EPM), object recognition, and location models for memory (ORT and OLT) at the end of the experimental period. Memory index was calculated.
The mice were sacrificed on day 22 and serum estrogen and testosterone levels and catalase, superoxide dismutase, and glutathione peroxidase activities were also evaluated. Lipid peroxidation was determined by measuring the malondialdehyde concentration in the brain sample.
The relationship between the gonadal hormone levels and the performance of animals in each of the neurobehavioural models for memory was positive. There was no significant difference in the malondialdehyde concentration (P < 0.05) of all groups in the males but in females between the control and vitamin C-treated group.
The activities of superoxide dismutase showed no significant difference in the males but showed significance (P < 0.05) between control and treatment groups in the females, catalase showed no significant difference in the females,
but showed significant difference (P < 0.05) between control and all groups and glutathione peroxidase showed no significant difference between all groups (P < 0.05) of both males and females. The memory index for the EPM also showed a significant difference (P < 0.05) between the vitamin E-treated group,
and the soya oil and vitamin C-treated groups on the first day and between vitamin E and C-treated groups on the second day in the females.
In the males, a significant difference was observed between the control and treatment groups on both days. In the ORT model, discriminatory and recognition indexes showed a significant (P < 0.05) difference in the vitamin E and E+C treated groups.
In the OLT model, discriminatory and cognitive indices showed a significant difference (P < 0.05) in the vitamin E and vitamins C+E treated groups. In conclusion, administration of vitamin C and E improved memory indices and there was a positive relationship between endogenous gonadal hormones and recognition.
TABLE OF CONTENTS
Title page – – – – – – – – – i
Declaration – – – – – – – – – ii
Certification – – – – – – – – – iii
Dedication – – – – – – – – – iv
Acknowledgements – – – – – – – – v
Abstract – – – – – – – – – vii
Table of Contents – – – – – – – – viii
List of Tables – – – – – – – – xii
List of Figures – – – – – – – – xiii
List of Abbreviations – – – – – – – – xv
CHAPTER ONE
1.0 Introduction – – – – – – – – 1
1.1 Statement of Research Problem – – – – – 6
1.2 Justification of Study – – – – – – – 7
1.3 General Aim of the Study – – – – – – 7
1.3.1 Specific Objectives of the Study – – – – – 7
1.4 Research Hypothesis – – – – – – – 8
CHAPTER TWO
2.0 Literature Review – – – – – – – 9
2.1 Oxidative Stress and the Nervous System – – – – 9
2.2 Vitamin C in the Nervous System – – – – – 11
2.3 Vitamin E and Memory – – – – – – 12
2.4 Sex hormones and Memory – – – – – – 13
2.4.1 Neurobiology of Oestrogen – – – – – – 14
2.4.2 Oestrogen and Cognition – – – – – – 16
2.4.3 Oestrogen and Learning and Memory – – – – – 17
2.4.4 Testosterone and Cognition – – – – – – 20
2.4.5 Gonadal Hormones and the Cholinergic system – – – 22
2.5 Cognition – – – – – – – – 22
2.6 Memory – – – – – – – – 22
2.6.1 Classification of Memory – – – – – – 23
2.7 Learning – – – – – – – – 26
2.8 Sex Differences in Cognitive functions- – – – – 27
CHAPTER THREE
3.0 Materials and Methods – – – – – – – 28
3.1 Site of experiment – – – – – – – 28
3.2.1 Experimental Animals – – – – – – – 28
3.2.2 Housing and grouping – – – – – – – 28
3.3 Drugs and soya oil preparation – – – – – – 29
3.3.1 Drugs and preparation – – – – – – – 29
3.4 Neurobehavioural Assessments- – – – – – 30
3.4.1 Elevated Plus Maze for Memory – – – – – 30
3.4.2 Object Recognition Test – – – – – – 30
3.4.3 Object Location Test – – – – – – – 33
3.5 Biochemical Tests – – – – – – – 37
3.5.1 Effect of Drugs on Brain Lipid Peroxidation – – – – 37
3.5.2 Evaluation of Brain Catalase Activity – – – – – 40
3.5.3 Evaluation of Brain Glutathione Peroxidase Activity – – – 40
3.5.4 Evaluation of Brain Superoxide Dismutase Activity – – – 41
3.6 Determination of Gonadal Hormone Levels – – – – 41
3.6.1 Determination of testosterone – – – – – – 41
3.6.2 Determination of Estrogen level – – – – – 43
3.7 Statistical Analysis – – – – – – – 44
CHAPTER FOUR
4.0 RESULTS – – – – – – – – 45
4.1 Neurobehavioural Assessments – – – – – 45
4.2 Elevated Plus Maze for Memory – – – – – – 48
4.3 Object Recognition Test – – – – – – – 51
4.4 Object Location Test – – – – – – – 51
4.5 Lipid Peroxidation Assessment – – – – – – 54
4.6 Gonadal Hormone Assay – – – – – – 57
4.7 Relationship between Serum Gonadal Hormones and Memory indices in mice 59
CHAPTER FIVE
5.1 Discussion – – – – – – – – 66
CHAPTER SIX
6.1 Summary – – – – – – – – 74
6.2 Conclusion – – – – – – – – 74
6.3 Recommendations – – – – – – – 74
References – – – – – – – – – 75
INTRODUCTION
Vitamin C, also known as L-ascorbic acid, is a water-soluble vitamin that is naturally present in some foods, added to others, and available as a dietary supplement and is destroyed by heat or reduced by prolonged storage (Weinstein et al., 2001).
Humans, unlike most animals, are unable to synthesize vitamin C endogenously, so it is an essential dietary component (Naidu, 2003; Li, 2007).
Sex steroids are hormones produced mainly by the reproductive glands, either the ovaries or testes, which share a similar basic structure of three hexane rings and a pentane ring (Gasbarri, 2010).
The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes, including cognition, neural development, and neural plasticity (Dohanich, 2002).
The hippocampal system plays an important role in memory function. Neurohormones like androgens and estrogens are present in the hippocampus and have important roles in learning and memory (Talebi et al., 2010).
Oestrogens act on the central nervous system (CNS) both through genomic mechanisms, modulating synthesis, release, and metabolism of neurotransmitters, neuropeptides, and neurosteroids, and through non-genomic mechanisms, influencing electrical excitability, synaptic function, and morphological features.
Therefore, estrogen’s neuroactive effects are multifaceted and encompass a system that ranges from the chemical to the biochemical to the genomic mechanisms, protecting against a wide range of neurotoxic insults (Genazzani et al., 2007).
REFERENCES
Abdulwahab, A., Mabrouk, M. A., Ayo, J. O., Ambali, S.F., Muftau, S., Adenkola, A.Y. and Salawu, E. A. (2010). Effects of co-administration of antioxidants on erythrocyte osmotic fragility of Wistar rats during the hot-dry season. European Journal of Scientific Research, 46: 73-79.
Adiga, V.S., Bhat, P., Chaturvedi, A., Bhair, K.L. and Kamath, S. (2012). Evaluation of the effect of ferula asafetida Linn. gum extract on learning and memory in wistar rats. Indian Journal of Pharmacology, 44 (1): 82-87.
Aiguo, W., Zhe, Y. and Gomez-Pinilla, F. (2010). Vitamin E protects against oxidative damage and learning disability after mild traumatic brain injury in rats. Neurorehabilitation and Neural Repair, 24 : 290-298.
Akpa, G.N., Asiribo, O.O., Alawa, J. P., Dim, N. L., Osinowo, O.A. and Abubakar, B.Y. (2002). Milk production by agropastoral Red Sokoto goats in Nigeria. Tropical Animal Production, 34: 526-533.
Antunes, M. and Biala, G. (2012). The novel object recognition memory, test procedure and its modifications. Cognition Process. 13: 93-110.
Arnold, A.P., Burk, J.A., Hodgson, E.M., Sarter, M., and Bruno, J.P. (2002). Differential acetylcholine release in rats performing a sustained attention task versus behavioural control tasks that do not task attention. Neuroscience, 114: 451-460.
Arque, G., Fotaki, V., Fernandez, D., Martinez de Lagram, M. and Arbones, M.L. (2008). Impaired spatial learning in mice haptoin sufficient for the dual specificity tyrosine-regulated kinase-1A (Dyrk1A). PLoS ONE Open access Journal, 3(7):e2575-2587.
Baddeley, A. (1992). Working memory. Science. 255: 556-559.
Baddeley, A.D. and Warrington, E.K. (1970). Amnesia and the distinction between long term and short term memory. Journal of Verbal Learning and Verbal Behaviour. 9: 176-189.
Baddeley, A. (1998). Working memory. Academy of Science III; 321:167-173.
Baddeley, A., Logie, R., Bressi, S., Della Salla, S. and Spinnler, H. (1986). Dementia and working memory. Journal of Experimental Psychology A, 38: 603-618.
Benfenati, F. (2007). Synaptic plasticity and the neurobiology of learning and memory. Acta Biomedica Brasiliensia, 78(1): 58-66.xiii
Bettis, T.J. and Jacobs, L.F. (2009). Sex-specific strategies in spatial orientation in C57BL/6J mice. Behavioural Processes, 82:249-255.
Black, S.H. (2004). Mechanisms of pro- and antioxidation. Journal of Nutrition, 134:3169S-3170S.
Blatt, D.H., Leonard, S.W. and Traber, M.G. (2001). Vitamin E kinetics and the function of tocopherol regulating proteins. Nutrition, 17 : 799-805.
Blatt, S.L., and Takahashi, R.N. (1998). Memory impairing effects of local anesthetics in an Elevated Plus Maze test in mice. Brazilian Journal of Medical and Biological Research, 31:555-559.
Bourre, J.M. (2006). Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients. Journal of nutrition heath and ageing, 10(5): 377-85.
Bowman, R.E., Zull, M.C., Lui ne, V.N. (2001). Object restraint stress enhances radial arm maze performance in female rats. Brain Research, 904: 279-289.
