ABSTRACT
Qualitative and quantitative screenings of the leaves of Eastern Nigerian mistletoe, Loranthus micranthus L., parasitic on six different plant species namely, Kola accuminata, Albizia adiantifolia, Anona cherimola, Citrus sinensis, Citrus auriantifolia and Pentaclethra macrophylla were carried out in the laboratories of Pharmacognosy and Biochemistry Departments of the University of Nigeria, Nsukka respectively. The results showed the presence of eleven phytochemicals namely: reducing sugars, terpenoids, resins, carbohydrates, saponins, proteins, alkaloids, steroids, glycosides, tannins and flavonoids and absence of oils and acidic compounds. The results also showed variations in concentrations of the phytochemicals in the leaves of L. micranthus from the various trees investigated. It is recommended that further studies be done to isolate, characterize, and identify the phytochemicals responsible for curing diseases, so as to facilitate biotechnological exploitation of the species in the production of potent orthodox drugs.
1.0 CHAPTER ONE
1.1 INTRODUCTION
In the developing countries such as Nigeria, Togo, Ghana and Cameron over 80% of the population, especially in the rural areas rely on traditional/ herbal medication for their health care delivery (Singh, 2004). Sofowora (2008) pointed out that dependence on herbal drugs for treating different ailments in rural areas was caused by the absence of orthodox medical doctors, low cost of the services rendered by the herbalists, and above all, the herbalists quickly attend to their patients, unlike in the hospitals where protocols bore down the patients before they (Patients) are given attention. Sofowora (1982) reported that every ailment has a cure in plants. The author further reported that in traditional medicinal practice, different parts of the plants are used either singly or in combination with other plant parts (The same plant or some other plant species) (Singh, 2006).
The appraisal of the roles of herbal drugs in health care delivery resulted in several declarations which led to the acceptance and encouragement of the development and use of herbal/ medicinal plants of known ethno-botanic origin by the World Health Organization (Paridhavi and Agrawal, 2007). Since the recognition of herbal drugs in treating diverse ailments, many advanced countries like; India, China, Prince Edward Island, etc. have documented the medicinal plants in their forests. Most of the identified medicinal plants have been biotechnologically exploited in the production of various types of drugs in the forms of concoctions, balms, powders, syrups, tablets, capsules and injections (Kannaiyan, 2005; Singh, 2006 and Paridhavi and Agrawal, 2007).
Singh (2004) and Singh (2006) reported that twenty best selling drugs developed and marketed globally by the United States of America were derived from plant bioactives. Currently, countless herbal drugs produced in developed countries like India and China are massively exported to the developing countries.
Nigeria is endowed with numerous medicinal plant species locally used in treating diverse ailments (Carlson et al., 1987; Adjanaboun et al., 1993; Okafor and Ham, 1999; Carlson and King, 2000; Sofowora, 2008). Several authors have reported some of the ailments/diseases that can be cured with herbal drugs (Khwaja et al 1986; Kleijnen and Knipschild, 1994; Newal et al., 1996 and Swanson-Flatt et al., 1989).
. These include: high blood pressure, diabetes, ulcer, constipation, rheumatism, hemorrhage, chest pain, blindness, acute headache, wounds, sore throat, cough, eczema, venereal diseases, infertility, low sperm count, arthritis, etc. (Osadebe and Ukwueze, 2004; Awono and Obot, 2008; Sofowora, (2008). Carlson and King (2000) revealed that plant parts used in traditional medicine include leaves, bark, wood, root and flowers. Carlson and King (2000) also reported that plant parts used in traditional medicine could be obtained from one plant or a combination of different parts of plant species. Sofowora (2008) reported that the effectiveness of the plant parts largely depends on the period and manner of collection. Several reports have shown that some plants have wide spectrum effects, thus can be used in curing many diseases. Some of such plants include; mistletoe (Osadebe and Ukwueze, 2004; Anon, 2005; Osadebe et al., 2012), Moringa oleifera (Onwuliri and Dawang, 2006) etc.
Following the contribution of medicinal plants to the socio-economy of nations, the advanced countries that biotechnologically exploited their medicinal plants have identified, documented and conserved their medicinal plants to ensure that they (Medicinal plants) can sustain industrial activities. Moran et al.,(2001) reported that biotechnological exploitation of medicinal plants and disposal of their products contribute significantly in generation of substantial revenue to nations as well as the rural dwellers on whose land the plants are found, and also to the companies that biotechnologically process the plants. Kannaiyan (2005) and Singh (2006) reported that exploitation of the medicinal plants creates a lot of job opportunities, helps to assemble intellectuals from different disciplines, and provides training opportunities for young intellectuals. It is expected that the developing countries like Nigeria can also benefit like the advanced countries when the medicinal plants in their forests are fully identified, documented, conserved, well researched upon and biotechnologically exploited. Of all the medicinal plant species in Nigerian forests that urgently need proper and extensive research attention for its biotechnological exploitation, drum stick/mistletoe (Loranthus micranthus),reported to be medicinally multipotential (Osadebe and ukwueze, 2004; Obatomi et al.,1996; Nzekwe et al.,2009; Omeje et al., 2011) quickly comes to mind hence has been chosen for this study.
1.2 DESCRIPTION AND CLASSIFICATION OF L. micranthus
CLASSIFICATION:
- Kingdom – Plantae
- Sub-kingdom – Tracheobionta
- Division – Magnoliophyta
- Class – Magnoliopsida
- Order – Santalales
- Family – Loranthaacea
- Genus –Loranthus
- Species –micranthus L.
African mistletoe (Loranthus micranthus) is commonly referred to as Eastern Nigerian mistletoe. The species is variously recognized as wonder plant, because of the wide spectrum effectiveness of its aqueous and ethanolic extracts in curing diverse ailments. The wide recognition of mistletoe as drumstick is because of the morphological shape of the basal woody portion that resembles sticks that are used in beating drum. Locally, the Ibos of the South-Eastern States of Nigeria recognize it as ‘Awuruse’ and the Yorubas of South Western States of Nigeria call it ‘Afomo’. Apart from L. micranthus, other species have been reported (Osadebe and Ukwueze, 2004). These include; Tapinanthus dodoneifolius, the Northern Nigerian species; Tipinanthus vitalus, the South African species; Pherodendron flavescens and Viscum album, American mistletoes etc.
The plant, Loranthus micranthus, has been described as a semi parasite (Obatomi et al., 1994). Nzekwe et al. (2009) described the species as an obligate parasite. Several authors have reported that the species is parasitic on a wide range of plants and is non selective of its hosts. Osadebe and Ukwueze (2004) reported that Loranthus micranthus is parasitic on Pentaclethra macrophylla, Kola accuminata, Baphia nitida, Persea americana, Azdirachta indica and Irvingia gabonensis. Nzekwe et al. (2009) reported that Treculia africana and Citrus spp. are also hosts of L. micranthus.Loranthus micranthus is an evergreen woody plant with thick, oppositely arranged obvate leaves that are green in colour. The stem is cylindrical in shape. The plant can grow to about 60cm in height. The species reproduce between November and December and produce flowers that are purple to red in color. The plant has been reported to be dependent on its host for growth. It attaches and penetrates through the branches of the hosts with the aid of its haustoria which absorbs nutrients from its host’s tissue (Water and mineral salts from the xylem and manufactured food from the phloem). Reports have shown that the species seeds are dispersed by birds that deposit them (Seeds) on tree branches where they germinate, grow and finally establish, forming a hanging bush (Plates 1 and 2) on its host (Osadebe and Ukwueze, 2004; Nzekwe et al. ,2009).
