Paradoxical Effects of Methanol Extracts of RicinuscommunisSeeds on Smooth Muscle Preparations.
ABSTRACT
The biphasic pharmacological activity of the aqueous methanol extract of Ricinus communis seeds on smooth muscles was investigated in this research.
The qualitative and quantitative phytochemical analysis for bioactive compounds in the methanol extract of the fermented and unfermented Ricinus communis seeds were carried out by the method of Trease and Evans and Harborne.
The median lethal doses of the two forms of extracts were determined by the method described by Lorke.
The qualitative phytochemical screening of the extracts showed relative presence of alkaloids, flavonoids, hydrogen cyanides, steroids, soluble carbohydrates, tannins and phenol in the fermented and unfermented extracts;
while glycosides, saponins and reducing sugars were not present in the fermented extract. The quantitative phytochemical screening of the extracts showed the presence of high quantities of reducing sugars, 39.60±0.00mg/100g,
soluble carbohydrates, steroids and alkaloids for the unfermented methanol extracts of Ricinus communis while the fermented extract revealed the presence of high quantities of tannins, 15.16±0.04mg/100g; flavonoids, 4.94±0.03mg/100g; and phenolics 12.62±0.04mg/100g.
TABLE OF CONTENTS
Title Page ……… i
Certification…..… ii
Dedication…………… iii
Acknowledgement……………… iv
Abstract……………….v
Table of Contents…………… vi
List of Figures……………. ix
List of Tables……………… x
CHAPTER ONE: INTRODUCTION AND LITERATURE REVIEW
1.0 Medicinal Plants…………..1
1.1 Ricinuscommunis ………… 2
1.1.1 Morphology and classification of Ricinuscommunis seeds……… 2
1.1.2 Taxonomical classification of Ricinuscommunis seeds…… 3
1.1.3 Pharmacological uses of Ricinuscommunis ….. 6
1.2.0 Phytochemistry………. 7
1.2.1 Phytochemical constituents of plants………… 8
1.2.1.1 Alkaloids……….. 9
1.2.1.2 Flavonoids……… 10
1.2.1.3 Glycosides……… 11
1.2.1.4 1.2.1.4 Tannins…… 12
1.2.1.5 1.2.1.5 Saponins……….. 13
1.2.1.6 1.2.1.6 Steroids…………14
1.3.Depolarization…………14
1.3.1 Hyperpolarization………… 14
1.3.2 Excitation-contraction coupling……… 15
1.3.3 Action potential of cell membranes…….…16
1.4.Muscles…………17
1.4.1 Muscle contraction and relaxation…………19
1.4.2 Smooth muscles………….20
1.4.2.1 Smooth muscle structure and organization………21
1.4.2.2 Smooth muscle contraction………22
1.4.2.3 Smooth muscle relaxation………24
1.5.0 Nervous system…….…………………26
1.5.1 Autonomic nervous system……………27
1.6.0 Uterus………………………29
1.6.1 Functions of the uterus………30
1.7.0 Jejunum…………………30
1.8.0 Aim and Objectives of the research…………32
CHAPTER TWO: MATERIALS AND METHODS
2.1 Materials……………….. 33
2.1.1 Plant material……… 33
2.1.2 Animals……………. 33
2.1.3 Drugs…………… 33
2.1.4 Equipment…………. 33
2.1.5 Chemicals and reagents………. 35
2.2 Methods………… 36
2.2.1 Preparation of plant material……….. 36
2.2.2 Extraction of plant material…………. 36
2.2.3 Experimental design ………….. 36
2.2.4 Preparation of reagents for phytochemical analysis………… 37
2.2.5Drug dilutions………… 38
2.2.5.1 Composition of physiological salt solution (PSS)………… 39
2.2.6 Qualitative phytochemical analysis of Ricinuscommunisseeds ……… 40
2.2.6.1 Test for alkaloids……………. 40
2.2.6.2Test for glycosides………….. 40
2.2.6.3 Test for steroids……………40
2.2.6.4Test for flavonoids………41
2.2.6.5Test for saponin…………41
2.2.6.6 Test for tannins…………41
2.2.6.7 Test for reducing sugars………41
2.2.6.8 Test for carbohydrates………42
2.2.7Quantitative phytochemical analysis of Ricinuscommunisseeds…….. 42
2.2.7.1 Alkaloid determination………… 42
2.2.7.2 Flavonoid determination………42
2.2.7.3 Glycoside determination……………42
2.2.7.4 Hydrogen cyanide determination……43
2.2.7.5 Phenol determination………43
2.2.7.6 Saponin determination………43
2.2.7.7 Soluble carbohydrates determination……43
2.2.7.8 Steroid determination………43
2.2.8Preparation of the methanol extract of unfermentedRicinuscommunisseeds for
the acute toxicity test……44
2.2.8.1 Acute toxicity test of the methanol extract of unfermentedRicinuscommunis
seeds………44
2.2.8.2 Preparation of the methanol extract of fermentedRicinuscommunisseeds for the
acute toxicity test……44
2.2.8.3Acute toxicity test of the methanol extract of fermentedRicinuscommunisseeds .44
2.2.9Smooth muscle experiment…………45
2.2.9.1Animal preparation……………45
2.2.9.2Determination of the effects of the extracts………45
(a) On the Rabbit isolated jejunum…………45
(b) On pregnant isolated uterus…………47
CHAPTER THREE: RESULTS
3.1.Percentage yield of the methanol extracts of fermented and
unfermentedRicinuscommunisseeds……… 49
3.2.Qualitative phytochemical screening of the methanol extracts of fermented and
unfermentedRicinuscommunisseeds……… 51
3.2.1 Quantitative phytochemical constituents of the methanol extracts of fermented and
unfermentedofRicinuscommunisseeds…… 53
3.3Median Lethal Dose (LD50) test of the methanol extract of unfermentedRicinus
communisseeds. …… 55
3.3.1Median Lethal Dose (LD50) test of the methanol extract of fermentedRicinus
communisseeds……57
3.4.Effects of the extracts on the isolated rabbit jejunum ……59
3.4.1 Effects of prazosin blockade of α- adrenoceptor……61
3.4.2 Effects of Indomethacin on extract induced relaxation……63
3.4.3Effects of prazosin on the isolated rabbit jejunum ……65
3.5Effects of the extracts on the isolated pregnant rat uterus……67
3.5.1Effects of prostaglandin synthesis inhibition….69
CHAPTER FOUR: DISCUSSION
4.1Discussion.……………71
4.2 Conclusion……………76
4.3 Suggestions for further studies ……76
REFERENCES………… 77
INTRODUCTION
Plants serveas rich sources of organic compounds, many of which have been used for medicinal purposes. Medicinal plants are the plants whose parts (leaves, seeds, stems, roots, fruits, foliage etc),
extracts, infusions, decoctions or powders are used in the treatment of different diseases of humans, plants and animals (Jamil et al.,2007). In the last few decades, there has been an exponential growth in the field of herbal medicine.
It is getting popularized in developing and developed countries, owing to its natural origin and lesser side effects. One of such medicinal plant is Ricinus communis (Euphorbiaceae), which is commonly known as Castor.
It is a small tree which is found all over the India (Manpreet et al., 2012). There is a wide spectrum of trees, plants and shrubs whose seeds, roots, barks and leaves are used by humans throughout the globe due to their nutritional or medicinal value (Abayomi, 1986).
In the last few years, there has been an exponential growth in the field of herbal medicine and these drugs are gaining popularity both in the developing and developed countries because of their natural origin and less side effects (Manisha et al., 2007).
However, these complementary components give the plant as a whole, the safety and efficiency much superior to that of its isolated and pure active components (Shariff, 2001).
REFERENCES
Abayomi, S. (1986).The State of Medicinal Plants Research in Nigeria. Proceedings of
Workshop, Nigeria Society of Pharmacology, Ile Ife. Pp. 261.Abo, K.A., Ogunleye, V.O. and Ashidi J.S (1991). Antimicrobial potential of Spondias
mombin,Advances in plant cell biochemistry and biotechnology, Vol. 1 Morrison IM, ed.
JAI Press Ltd, London (UK), Pp. 151-217.Aguilar, H.N., Xiao, S., Knoll, A.H and Yuan, X. (2010). Physiological pathways and molecular
mechanisms regulating uterine contractility.Human Reproduction Update,16 (6): 725-744.Ajibesin, K.K., Ekpo, B.A., Bala, D.N., Essien, E.E. and Adesanya, S.A. (2008). Ethnobotanical
survey of Akwa Ibom State of Nigeria, Journal of Ethnopharmacology, 115 (3): 387-408.Akinmoladun, A.C., Ibukun, E.O., Afor, E., Obuotor, E.M. and Farombi, E.O. (2007).
Phytochemical constituent and antioxidant activity of extract from the leaves of Ocimum
gratissimum.Scientific Research and Essay. 2(5): 163-166.Akah, P.A., Okoli, C.O. and Ndu, O.O. (2007).Experimental Methods in Physiology and
Pharmacology.ABIC Books, Enugu. Pp. 97-114.
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