Collection, Identification, and Preservation of Medical Plants
CHAPTER ONE
Objectives Of Study
- To establish a collection of medicinal plants used in management of depression by traditional medical practitioners in Enugu, Nigeria.
- To establish the phytochemical constituents present in the plants.
- To determine the effect of most active plant on anhedonia in mice.
CHAPTER TWO
Traditional medicine
Plants have been utilized as medicines for thousands of years (Samuelsson, 2004). These medicines initially took the form of crude drugs such as tinctures, teas, poultices, powders, and other herbal formulations (Balick and Cox, 1997; Samuelsson, 2004). The specific plants to be used and the methods of application for particular ailments were passed down through oral tradition. Eventually information regarding medicinal plants was recorded in herbal phamacopoeias (Balunas, 2005).
Modern allopathic medicine has its roots in ancient medicine, and it is likely that many important new remedies will be discovered and commercialized in the future, as it has been till now, by following the leads provided by traditional knowledge and experiences. While European traditions are particularly well known and have had a strong influence on modern western pharmacognosy, almost all societies have well-established herbal traditions, some of which have hardly been studied at all. The study of these traditions will not only provide an insight into how the field has developed but it is also a fascinating example of our ability to develop a diversity of cultural practices.
In some countries, the use of medicinal plants is often associated with witchcraft and superstition, because people do not have the scientific insight to explain and predict the curative action of plants. One example of such an irrational concept is the Doctrine of Signatures, elements of which are found in many of the healing cultures of the world (Boehme, 1982). It is based on the assumption that the appearance of plants may give clues to their medicinal properties—it is interpreted as God’s signature on the plant. Red juice and sap, for example, is associated with blood and menstrual ailments; yellow flowers with bile and jaundice; the human shape of certain roots with the female form of fertility and so on. Sometimes this concept however, worked: Chelidonium majus, contains yellow flowers and a yellow alkaloid containing latex, and has been used successfully to treat jaundice (Gurib-Fakim, 2006).
African traditional medicine
African traditional medicine is ancient and perhaps the most diverse of all medicinal systems. Africa is considered to be the cradle of humankind, with a rich biological and cultural diversity and marked regional differences in healing practices. Unfortunately, even today the systems of medicines are poorly recorded. The documentation of medicinal uses of African plants is becoming increasingly urgent because of the rapid loss of the natural habitats of these plants due to human activities. The African continent is reported to have one of the highest rates of deforestation in the world. This loss is all the greater because the continent has a high rate of endemism, with Madagascar topping the list at 82% (Green and Sussman, 1990).
CHAPTER THREE
MATERIALS AND METHODS
Materials
Drugs and Chemicals
The followings are some of the chemicals used for the experiment.
Imipramine (Tofranil GSK brand USA), Diazepam (Roche, France), Methanol (FlukaAldrich), Cortisol Enzyme-linked immunosorbent assay (ELISA) kit (Wuhan Fine Biotech Co. Ltd, Catalogue No. EM1721), Brain derived neurotrophic factor enzymelinked immunosorbent assay kit (ELISA) kit (Wuhan Fine Biotech Co., Ltd., Catalogue
Equipment and other Materials
Animal cages, pestle and mortar, syringes (1 ml, 2 mls, 5 mls and 10 mls), filter paper, pair of scissors, mettler balance p165, measuring cylinders, separating funnel, beakers, test tubes, funnel, test tube holders, crucible, water drinkers, Incubator (model: DHP9035A), Spectrophotometer (model: Spectrumlab 23A) and microplate reader (RaytoRT-2100C).
Animals
Swiss Albino mice (18-22 g) of either sex were obtained from the Animal House Facility of the Department of Pharmacology and Therapeutics, Enugu state University. They were housed in improvised propylene cages and kept under natural day and light cycle. The animals were fed on standard laboratory animal diet and water ad libitum.
Methods
The research was conducted in three phases.
Phase 1: Ethnobotanical survey, plants collections and extractions, then phytochemical screening.
Phase 2: Acute and neurotoxicity studies, followed by antidepressant studies which validated the folkloric claim of the surveyed plants.
Phase 3: The most active plants was selected for further depressive and mechanistic studies.
CHAPTER FOUR
RESULTS AND DISCUSSION
Ethnobotanical Survey
Demography of Respondents in an Ethnobotanical Survey of Medicinal
Plants Commonly Used in Nigeria
A total of ten respondents made up of herb sellers 2 (20%), traditional medical practitioners 6 (60%) and herbalists 2 (20%). Majority (90%) of the respondents were males as observed from demographic information of respondents (Table 4.1).
CHAPTER FIVE
CONCLUSION AND RECOMMENDATIONS
Conclusion
The knowledge of herbal medicines for complicated treatment of diseases is confined to mostly the practicing herbalists or plant scientists with the belief that herbal medicines will lose their potency if revealed to other people. Although some herbs may have medicinal values, sometimes the medicinal preparations inflict certain side effects. The special significance of medicinal plants in treatment of diseases relates to the phytochemical present. The study showed that all the medicinal plants (in Nigeria) contain bioactive components known as phytochemicals. Therefore, the therapeutic or medicinal applications of these plants could be due to the presence of bioactive components.
The study established a collection of medicinal plants used in the management of depression by traditional medical practitioners in Enugu and their use in the management of depression was validated. Phytochemical constituents found in the chromatographic finger print may be responsible for the observed activity. The acute toxicity studies revealed the relative safety of the plants. The plant Adansonia digitata was found to be very promising which reversed the chronic mild stress induced depression and elicited antidepressant activity via the monoaminergic, neurotrophic, metabolic, nitric oxide and neuroendocrine systems.
Recommendations
- Further antidepressant studies should be conducted on the other medicinal plants.
- The activity of Adansonia digitata on inflammatory pathways and down stream mediators of depression as the possible mechanism of action should also be considered.
- Bioassay guided fractionation should be conducted to isolate and characterize the bioactive constituents responsible for the antidepressant activity of Adansonia digitata.
References
- Abdullaev, F.I. (2002). Cancer chemopreventive and tumoricidal properties of saffron (Crocus sativus L.). Experimental Biology and Medicine, 227: 20-25.
- Abe, K. and Saito, H. (2000). Effects of saffron and its constituent crocin on learning behavior
- Bevins, R.A. and Besheer, J. (2006). Object recognition in rats and mice: a one trial nonmatching-to-sample learning task to study ‘recognition memory’. Nature Protocols, 1: 1306-1311.
- Bhutani, M.K., Bishnoi, M. and Kulkari, S.K. (2008). Antidepressant-like effects of Curcumin and its combination with piperine in unpredictable chronic stressinduced behavioural, biochemical and neurochemical changes. Pharmacology, Biochemistry and Behaviour, 9(2009): 39-43.
- Bilici, M., Efe, H., Koroglu, A., Uydu, H.A., Bekaroglu, M. and Deger, O. (2001). Antioxidative enzyme activities and lipid peroxidation in major depression: alterations by antidepressant treatments. Journal of Affective Disorders; 64:3–51.
- Biology Encyclopedia (2015). Secondary Metabolites in Plants – Biology Encyclopedia, Advameg, Inc. pp. 379.
- Bockting, C.L.H., ten Doesschate, M.C., Spijker, J., Spinhoven, P., Koeter, M.W.J. and Schene, A.H. (2008). Continuation and maintenance use of antidepressants in recurrent depression. Psychotherapeutics Psychosom, 77: 17 -26.
