Preliminary Investigations on the Ethnomedicinal Plants of Akoko Division , South West Nigeria

An account of sixty ethnomedicinal plant species belonging to thirty two families used extensively in different parts of Akoko division of Ondo State, South West Nigeria is highlighted. The parts of the plant species used in the treatment of various diseases ranged from leaves, stem, root, and bark to fruit only, or a combination of two or more parts from a single species or with those of other species. Their mode of application has also been discussed.


Introduction
During the past decade, traditional medicinal practices have become a topic of global relevance.In many developing nations, a significant number of indigenous populations rely on medicinal plants to meet their health care needs.According to Lewis and Elvin-Lewis (2003), botanically derived medicinals have played a major role in human societies throughout history and prehistory and people have used plants as medicine since the beginning of civilization, as they were believed to have healing powers (Connie and King 2003).
The use of plants in the tropical and subtropical regions is diversified and most of the uses are for medicine, source of food, clothing and shelter.But the medicinal uses of plants are rapidly declining among the present generation of local people as a consequence of modernization and civilization (Cox 2005).The younger generation is showing little interest in learning this valuable science of healing.Usage of medicinal plants to cure diseases has also been much influenced by religious practices (Trease andEvans 1989, Wambebe 1999).
All over the world, several ethnobotanical studies focusing on medicinal plants have been documented (Ekpendu et al. 1998, Balansard and Timon 2000, Singh and Singh 2001, Wang et al. 2002, Cox 2005, Kumar et al. 2005, Pei 2005).But in Nigeria, very little information about ethnobotanical studies has been documented (Gill 1992, Sofowora 1993, Igoli et al 1999).Therefore the need for proper documentation of traditional medicinal practices among the Akoko people in Nigeria where there has been a dearth of published information is immediately called for and this accounts for the rationale to undertake the present study.

Study area
Akoko region is situated between Longitudes 5.18 0 and 5.52 0 E and Latitudes 7.18 0 and 7.47 0 N.It is characterized by a mixture of a lowland rainforest and savannah vegetation with an annual rainfall ranging 800 -1500mm and a mean annual temperature of 28 0 C -35 0 C. It covers four local government areas and occupies the Northeastern side of the present Ondo State, Nigeria.It has an area of about 1360 kilometers (Akoko North Information Division, 1978).It is bounded in the north and northeast by Kabba in Kogi State, and to the west and North-west by Ekiti central and North respectively.

Methods
Plant collection and identification: A total of 180 questionnaires were administered and interviews were conducted with the old and local traditional healers in forty villages in all the four local government areas that comprise the study area.The author accompanied some of the respondents to the field to collect the plant materials.Throughout the interviews, the local names of the plants, the parts used, method of preparation of crude drug from the plants, mode of application, dosage and duration of treatment (where specific) were recorded.Only species consistently used to treat the same illness by several healers/villages across the study area were selected.In cases where the plant species were not immediately identifiable with botanical names, they were brought to the Department of Plant Science and Biotechnology laboratory, Adekunle Ajasin University, Akungba-Akoko, where they were identified using relevant keys.
Herbarium voucher specimens were prepared following the standard techniques (Martin 1995, Lawrence 1967) and were thereafter deposited in the Herbarium of the Department of Plant Science and Biotechnology, Adekunle Ajasin University, Akungba-Akoko.

Results and discussion
Plant species belonging to sixty species and thirty-two families were identified as being used by most of the people of this area for the treatment of various common diseases.Table 1 showed the list of the species, botanical name, local name, uses and parts used.Some of these plants are cultivated by the people themselves while others grow in the wild.
Of the 32 different families which the people of this area consult for medicinals, the family Euphorbiaceae has the largest number of species (eight), followed by Asteraceae with (six) species while the families Caesalpiniaceae, Fabaceae, and Anacardiaceae recorded three species respectively.
This study has revealed that traditional medicinal practices have a wide acceptability among the Akoko people probably because they believe in its effectiveness and also due to their lack of access to modern health care delivery system.Also the unavailability and unaffordability of orthodox drugs may also have contributed largely to preference of traditional medicine over the orthodox drugs.
The medicinal uses are varied and the plant species parts that are used range from leaves, roots, stem, bark to fruits only, or a combination of two or more in a species or with those of other species.
For common diseases like cuts and wounds, Milicia excelsa, Chromolaena odorata, Aspilia africana, Manihot esculenta are used for fast healing of wounds.This may only indicate that these plants contain therapeutic compounds such as vitamins c and some amino acids which are responsible for the fast healing of wounds.Others like eye defects and ear infections are treated using Alchornea cordifolia and Bryophyllum pinnatum, Jatropha curcas respectively.Diseases such as coughs are cured using varieties of taxa such as Abrus precatorius, Ocimum gratissimum, Garcinia kola and Terminalia macroptera.Euphorbia hirta is used for the treatment of asthma while Cassia alata and Parquetina nigrescens are used as tonic (blood purifier).Cymbopogon citratus, Blighia sapida and Ocimum gratissimum are also effective in the relief of chest pains.Some plants are believed to contain chemicals which possess anti-malarial properties such as Chromolaena odorata, Mangifera indica, Citrus aurantifolia Psidium guajava, Nauclea latifolia, Bridelia ferruginea, Cymbopogon citratus, Anacardium occidentale, Alstonia boonei and Azadirachta indica.These plants are not commonly used individually to cure malaria but two or more of the plants are combined together for the treatment of malaria.Khaya senegalensis is used to cure typhoid fever while Acanthospermum hispidus is used for yellow fever.Others such as Azadirachta indica and Bridelia ferruginea are combined together for the treatment of Jaundice.
Critical ailments such as epilepsy are cured using the leaves of Bryophyllum pinnatum and Emilia sonchifolia when made as concoction and administered orally to the patient while scrotum elephantiasis is cured with the leaves of Newbouldia laevis and tuberculosis with Acanthospermum hispidus leaves.The people of Akoko also use Azadirachta indica to cure small pox and chicken pox.Diabetes is cured using the root extract of Urena lobata.Ficus capensis and Pupalia lappacea are used for the treatment of Leprosy while Cajanus cajan and Carica papaya are used for hypertension and ulcer respectively.Bridelia ferruginea and Anacardium occidentale found to be effective in the treatment for coated tongue.
Skin infections like eczema, pimples, rashes are cured by rubbing the leaves of Jatropha gossypifolia, Borreria sp., Hymenocardia acida and Allamanda cathartica on the infected parts of the skin.Acalypha hispida is known to confer anti-bacterial and anti-fungal properties and therefore leaf decoction is administered to infants for skin rashes.
For sexually transmitted diseases, the people of this area relies on Vernonia amygdalina for vagina itch and Azadirachta indica for syphilis.Plants such as Alchornea cordifolia and Carica papaya are used for the treatment of gonorrhoea.
Stomach disorders are cured using varieties of plants viz: Vernonia amygdalina, Bidens pilosa, Terminalia macroptera and Spondias mombin; Kwashiorkor and gastroenteritis are cured using Daniella oliveri while constipation and indigestion are treated using Parkia biglobosa and Ananas comosus.Momordica charantia, Nauclea latifolia and Vigna ungiculata are used as vermifuge.Diarrhoea and dysentery are treated with Ocimum gratissimum, Bidens pilosa and Allamanda cathartica.Some plants are also used for preventive purposes, for example, seven very young twigs of Annona senegalensis and seven seeds of Aframomum melegueta are eaten to prevent snake bite.Also plants such as Nicotiana tabacum and Datura metel are planted around houses to prevent and repel the snakes.The indigenous people of Akoko region believe that some plants could confer longevity (increase their life span), for example, Spondias mombin is used to bath infants because its name "iyeye" means survival and Garcinia kola is used during naming ceremonies because its name "orogbo", means long life.Bryophyllum pinnatum may also be put on window frames as it is believed that since the plant does not die easily, whoever that keeps it will live long.
The people of this area use plants such as Glyphaea brevis and Abrus precatorius to induce labour, while Alchornea cordifolia and Heliotropium indicum are used for foetal development and arrest abortion or for miscarriage respectively.

Conclusions and recommendation
This study has revealed that ethno-medicinal practices are well accepted by the people of this area.Information made available by the respondents revealed that the uses of these plants are almost unaltered as it was used in the past and may likely continue to remain in the future if properly documented and the plants are conserved.It is suggested that an enduring and sustainable conservation efforts be put in place by the community and government to safeguard these important medicinal plants.