Conservation of indigenous medicinal botanicals in Ekiti State, Nigeria

Abstract

The rapid appraisal method was used to identify the botanicals used ethnomedicinally from a total of 300 randomly selected respondents drawn from the existing three geo-political zones of Ekiti State, Nigeria. The results obtained revealed that about 40% of the 71 botanicals identified presently rare. Most of the presently abundant botanicals are species primarily cultivated for other purpose other than medicine. Most of the identified species are valued for their curative effects on malaria and fever, the predominant diseases in the study area. The need for the conservation of the rare species cannot be over emphasised as most rural dwellers in the study area depend mostly on herbs from these species. Strategies towards the attainment of this goal are proposed.

INTRODUCTION

Ekiti State (about 7000 km², Inland area) is situated between 7°25′ and 8°20′ North and 5°00′ and 6°00′ East in the rainforest belt of southwestern Nigeria (EKSG, 1997; Kayode, 1999; 2000). The state which was previously rich in botanicals is now being confronted with massive deforestation due to increase in population, urbanization, uncontrolled logging, lumber being used as fuel and developmental activities since the state was created in 1996.

Although studies on the ethnomedicinal utilization of botanicals abound in Nigeria, these studies were conducted on scattered basis usually by various ethnic groups of the country. Presently, a gross dearth of documentation abounds on the ethnomedicinal utilization of botanicals among the Ekiti, a distinct Yoruba tribe that constitutes over 98% of the 1.6 million inhabitants (EKSG, 1997) of the state.

The study being reported here is part of an ongoing project aimed at the evaluation and conservation of useful flora species in Ekiti State currently being conducted at the Department of Plant Science, University of Ado-Ekiti, Ado-Ekiti, Nigeria.

MATERIALS AND METHODS

Ekiti State was divided into three zones based on the existing political delineation (Fig.1). In each zone, 15 rural communities were randomly selected: Aye-oja (1), Akola (2), Ido-ajinare (3), Aba-obanla (4), Ita-ore (5), Irele (6), Ayebode (7), Ire (8), Ayegbaju (9), Orin (10), Orun (11), Ajegunle (12), Ogbese (13), Obada (14) and Ogotun (15). In each community, 20 respondents were randomly selected and interviewed with the aid of semi-structured matrix. The interviews were focused and conversational (Martins, 1995; Kayode et al., 1997; Kayode, 2003).

Fig. 1.

Map of Ekiti State, Nigeria showing the study sites

Medicinal botanicals used were identified and voucher specimens collected (Lipp, 1989). The parts of the plant used, doses formulation, sources of plants collections, were defined and documented. Plants identified were later confirmed and voucher specimens deposited at the Herbarium of the Department of Plant Science, University of Ado-Ekiti, Nigeria. Field information was confirmed by Balick and Cox (1996).

The relative abundance of the identified botanicals in a 10 km² land area within the identified major source(s) was defined according to Bongers et al.(1988) and Kayode (1999) as: Less than 5 individuals as ‘rare’, 5 to 10 as ‘occasional’, 11 to 30 as ‘frequent’, 31 to 100 as ‘abundant’ and over 100 individuals as ‘very abundant’.

RESULTS AND DISCUSSION

A total of 71 botanicals belonging to 41 families (Table 1) were identified as being valued for ethnomedicinal purpose in all of the study area. A considerable proportion of these species were found to be ‘rare’ on the abundance scale (Table 2). Among the common ones, very few species were found to be on the ‘very abundant’, ‘frequent’ and ‘occasional’ scales. Most of the botanicals on the ‘abundant’ scale were botanicals cultivated and those that germinated as weeds (Table 2). Although, forest and household farms constituted the major sources of the botanicals, field observations revealed that most of the rare species were still sourced from the forest.

Table 1.

Identified botanicals used ethnomedicinally in Ekiti State, Nigeria

Family	Species	Local (Ekiti) name	Part(s) used*	Major source**	Abundance	Folk medicinal uses
Ameranthaceae	Alteranthera repens	Dagunro	RT, BK, LV	FOR	Rare	Rheumatism
	Amaranthus spinosus	Tete-elegun	RT, ST, LV	FM	Abundan	Diarrhea, Dysentery, Gonorrhea
	Celosia argentea	Sokoyoto	LV	FM	Abundant	Diarrhea
Anacardiaceae	Anacardium occidentale	Kaasu	LV, BK	FM, HHA	Abundant	Malaria, Asthma, Leprosy
	Mangifera indica	Mangoro	ST, LV, BK	FM, HHA	Very abundant	Malaria, Diarrhea, Diabetics
Annonaceae	Enantia chlorantha	Oso pupa	RT	FOR	Rare	Malaria, Jaundice, Antipyretic
Apocynaceae	Alstonia boonei	Ahun	ST, BK	FOR	Rare	Malaria, Rheumatism
	Raufolfia vomitoria	Ira	RT, ST, LV	FOR	Occasional	Fever, Dysentery, Diarrhea
Asclepiadaceae	Calotropis procera	Bomubomu	RT, LV	FM	Abundant	Eczema, Leprosy, Elephantiasis, Asthma, Cough, Rheumatism
Bombaceae	Adansonia digitata	Ooshe	LV, BK, RT	FOR	Rare	Malaria, Dysentery, Diarrhea, Asthma
	Ceiba pentandra	Egigun	LV, BK	FOR	Rare	Fever, Asthma, Headache, Diabetes
Boranginaceae	Cordia melenii	Omo	BK	FOR	Rare	Fever, Cough, Stomachache
Bromeliaceae	Annas comosus	Ope-oyinbo	FR	FM	Abundant	Stomach problems
Cannaceae	Canna indica	Ido	LV	FOR	Rare	Malaria
Caricaceae	Carica papaya	Ibepe	LV	FM, HHA	Abundant	Malaria, Diabetics, Stomach disorder
Combrataceae	Terminalia ivorensis	Idigbo	ST	FOR	Rare	Stomach ache
	Terminalia superba	Afara	RT, ST	FOR	Rare	Laxative
Compositae	Chromolaena odorata	Akintola	LV	FM, HHA	Very abundant	Malaria
	Vernonia amygdalina	Ewuro	LV	FM, HHA	Abundant	Hypertension
Convolvulaceae	Ipomoea batatas	Kunkunduku	LV, RT	FM	Occasional	Asthma
Cucurbitaceae	Momodica charantia	Ejirin-wewe	LV	FOR, FM, HHA	Abundant	Vermifuge, Jaundice
Euphorbiaceae	Acalypha chiliate	Ewon-bonni	LV	FOR	Rare	Asthma, Rheumatism, Bronchitis
	Jatropa curcas	Lapalapa	LV, ST, RT, SD	FM, HHA	Occasional	Ringworm, Eczema, Ulcer
	Jatropa gossypifolia	Lapalapa-pupa	ST-Latex	FM, HHA	Occasional	Ringworm
Gramineae	Bambusa vulgaris	Oparun	LV	FOR, FM, HHA	Abundant	Gonorrhea, Worm expeller
Gutiferae	Allanblackia floribunda	Orogbo-erin	LV, BK	FOR	Rare	Malaria, Dysentery
	Garcinia kola	Orogbo	BK, SD	FOR	Occasional	Fever, Cough, Hepatitis, Headache
Hyperricaceae	Harungana madagascariensis	Elepo	BK	FOR	Rare	Fever, Cough, Cold, Dysentery, Jaundice
Labiatae	Ocimum basilicum	Efinrin-wewe	LV, ST, FR	FM, HHA	Abundant	Head ache, Cough, Gonorrhea
	Ocimum gratissimum	Efinrin-ajase	LV	FM, HHA	Abundant	Fever, Cold, Cough, Diarrhea
Leguminosae	Cajnus cajan	Otili	LV, SD	FM	Abundant	Smallpox, Chicken pox
	Desmodium gangetium	Emimo	LV, RT	FM, FOR	Frequent	Fever, Asthma, Dysentery, Diarrhea
	Parkia biglobosa	Iru	ST, LV, FR	FM	Frequent	Malaria, Fever
	Pterocarpus erinaceus	Apepe	LV, ST	FOR	Rare	Dysentery, Diarrhea
	Pterocarpus osun	Osun	LV, ST	FOR	Rare	Skin diseases
Liliaceae	Allum cepa	Alubasa	FR, SD, LV	FM	Abundant	Stimulant, Cough
Lythraceae	Lawsonia inermis	Laali	LV	FM, FOR	Rare	Jaundice, Gonorrhea
Malvaceae	Hibiscus sabdariffa	Isapa	LV	FM	Frequent	Cough
	Sida acuta	Iseketu	LV	FM, HHA	Frequent	Malaria, Ulcer, Fever
Meliaceae	Azadirachta indica	Dongoyaro	LV, BK	HHA, FM	Frequent	Malaria, Piles, Syphilis, Roundworms, Antiseptic
	Carapa procera	Urere	BK, SD, LV	FOR	Rare	Ringworm, Boils, Dressing, Rheumatism
	Entadrophragma cylindricum	Igebu	BK	FOR	Rare	Fever, Cough, Black tongue
	Kyaya senegalensis	Oganwo	ST, RT	FOR	Rare	Malaria, Jaundice
	Lovoa trichilioides	Koko-igbo	ST, BK	FOR	Rare	Cough, Yellow fever
Moraceae	Antiaris africana	Oro	ST, BK	FOR, FM	Occasional	Rheumatism
	Ficus capensis	Opoto	LV, ST, RT	FOR	Occasional	Dysentery, Leprosy, Epilepsy
	Melicia excelsa	Iroko	RT, BK	FOR	Rare	Rheumatism
Myrtaceae	Psidium guajava	Guafa	LV	FM, HHA	Frequent	Malaria, Cough, Urinary diseases, Stomach ache
Myriticaceae	Pycnanthus angolensis	Akomu	LV, ST, RT	FOR	Rare	Anthelmintic
Nyctaginaceae	Boerhaovia diffusa	Eti-elela	RT, ST, LV	FOR, FM	Abundant	Asthma, Gonorrhea
Ochnaceae	Lophira alata	Ekki	LV, BK, RT, SD	FOR	Rare	Malaria, Cough, Jaundice, Gastrointestinal disorders
Palmae	Cocos nucifera	Agbon	RT, BK, FT	FM, HHA	Frequent	Bronchitis, Dysentery
	Elaeis guineensis	Ope	RT	FM	Abundant	Malaria
Papilionaceae	Baphia nitida	Igi-osun	RT, BK	FOR	Occasional	Ulcer Boils, Dressing
Rubiaceae	Morinda lucida	Oruwo	ST, LV	FOR	Rare	Malaria, Diabetics
	Morinda morindioides	Oju-ologbo	RT, LV, FR	FOR	Rare	Fever, Jaundice
Rutaceae	Citrus aurantifolia	Orombo-wewe	LV, ST, RT, FR	FM, HHA	Occasional	Fever, Jaundice, Headache
	Citrus aurantium	Gayinganyin	RT, FR	FM, HHA	Occasional	Cough, Rheumatism, Sore throat
	Citrus sineensis	Orombo	ST	FM, HHA	Abundant	Malaria, Fever, Dysentery, Headache, Vermifuge
	Fagara zanthoxyloides	Ata	RT, BK	FOR	Rare	Gonorrhea, Sickle cell anemia
Sapindaceae	Bligha sapida	Ushin	BK	FM, HHA	Frequent	Malaria, Ulcer, Backache, Head ache
	Lecaniodiscus cupenioides	Akika	ST, RT, LV	FOR	Rare	Malaria, Fever, Dressing
Sapotaceae	Chrysophyllum albidum	Agbalumo	ST, BK	FM	Occasional	Fever
Solanaceae	Capsicum frutescens	Ata	FR	FM	Very abundant	Malaria, Fever, Dysentery
Sterculiaceae	Cola acuminata	Obi-abata	BK, SD	FM	Abundant	Stimulant, Diarrhea
	Cola nitida	Obi-gbanja	BK, SD	FM	Abundant	Stimulant, Diarrhea
Tiliaceae	Glyphaea brewis	Atori	LV	FOR, FM	Occasional	Gonorrhea, Diarrhea, Fever, Dressing
	Trumfeta cordifolia	Esua	LV	FOR	Rare	Malaria, Laxative
Ulmaceae	Trema guineensis	Ofoforo	LV	FOR	Rare	Fever, Cough, Bronchitis, Dysentery, Pneumonia
Violaceae	Hybanthus enneaspermus	Abiwere	LV, ST, RT	FOR, FM	Occasional	Painless delivery
Zingiberaceae	Afromomum melegaeta	Ata-ire	FR, SD, LV	FOR, FM	Frequent	Stimulant, Smallpox, Chicken pox

^*RT=Roots, BK=Barks, FR=Fruits, LV=Leaves, SD=Seeds, ST=Stems

^**FOR=Forest, FM=Household farm, HHA=Household area

Table 2.

Eco-demographic records of the identified botanicals in Ekiti State, Nigeria

Botanicals mostly sourced from household farms were mostly cultivated and weed species. The germinated botanicals were dominated by species whose fruits constituted a major source of income in the study area. In these species, the medicinal products were merely considered as secondary products. Thus income generation constitutes the major incentives for their cultivation. The most frequently occurring species among the weeds was C. odorata. This species occurred in large number in all the sources considered in this study. The ecological success of this weed was attributed by Kayode (1999) to its rapid dispersal by wind, its easy establishment in the study area (Etejere, 1980), the existence of a bank of its seeds in the soil of early successional area (Kamakrishnan and Mishra, 1982) and the increased longevity of its seeds due to enforced dormancy after their burial in the soil. The same attributes might be responsible for the occurrence of other weed species obtained in this study.

Most of the botanicals identified in this study were being utilized against malaria and fever, which according to Kayode (2004) are the prevalent diseases in the study area. There is therefore the need to conserve many of the species especially those that were observed to be rare. These botanicals were mostly tree species. Dependence on them is based on those growing in the wild. At present, among limiting factors against their cultivation are the fragmentations resulting from the prevailing land tenure system, the apparent lack of silviculture and biological knowledge of these botanicals and ignorance of the consequences of their loss by the local farmers in the study area. An urgent conservation strategy should be developed to preserve these species for the use of the present and future generations. Such strategy should encourage the domestication of botanicals identified, provide clues to their ecology, enlighten the populace about the dangers in the loss of biological diversity and accommodate the indigenous farmers in both planning and execution of the strategy.