Ethnobotanical Survey of antimalarial plants used in Ogun State, Southwest Nigeria

Abstract

An ethnobotanical survey of herbal medicine used for treatment of malaria fever in 17 communities in Ogun State, Southwest Nigeria was carried out. According to the results, 38 plant species belonging to 24 families were used in herbal antimalarial recipes. Among the plants mentioned, the most frequently used were Morinda lucida (7.87%), Lawsonia inermis (7.41%), Citrus medica (6.94%), Sarcocephalus latifolius (6.48%) and Morinda morindiodes (6.48%). Investigations were carried out on the plant part (leaf, stem or root) used, method of preparing herbal antimalarial remedies and how it is administered. Result showed that irrespective of plant and part (leave, fruit, stem bark or root bark) or combinations of the plant parts, water and aqueous extract from fermented maize were the main medium of herbal antimalarial preparations. Treatment regimens of malaria generally included drinking, bathing and steam inhalation of the aqueous herbal preparations for 4 -10 days or until symptoms of malaria disappear. About 65% of all the plants mentioned in the survey have been documented to have toxic effect on the liver and kidney of experimental mice. Continuous consumption of these plants could therefore have pathological effects on the consumers. Hence, this show the need for more research in order to identify lead compounds in indigenous antimalarial plants with less or no toxicity.

Full text

African Journal of Pharmacy and Pharmacology, Vol. 4(2) pp. 055-060, February 2010
Available online http://www.academicjournals.org/ajpp
ISSN 1996-0816 © 2010 Academic Journals
Full Length Research Paper
Ethnobotanical survey of antimalarial plants used in
Ogun State, Southwest Nigeria
O. A. Idowu, O. T. Soniran, O. Ajana and D. O. Aworinde
Department of Biological Sciences, University of Agriculture, Abeokuta, Ogun State, Nigeria.
Accepted 18 December, 2009
An ethnobotanical survey of herbal medicine used for treatment of malaria fever in 17 communities in
Ogun State, Southwest Nigeria was carried out. According to the results, 38 plant species belonging to
24 families were used in herbal antimalarial recipes. Among the plants mentioned, the most frequently
used were Morinda lucida (7.87%), Lawsonia inermis (7.41%), Citrus medica (6.94%), Sarcocephalus
latifolius (6.48%) and Morinda morindiodes (6.48%). Investigations were carried out on the plant part
(leaf, stem or root) used, method of preparing herbal antimalarial remedies and how it is administered.
Result showed that irrespective of plant and part (leave, fruit, stem bark or root bark) or combinations
of the plant parts, water and aqueous extract from fermented maize were the main medium of herbal
antimalarial preparations. Treatment regimens of malaria generally included drinking, bathing and
steam inhalation of the aqueous herbal preparations for 4 - 10 days or until symptoms of malaria
disappear. About 65% of all the plants mentioned in the survey have been documented to have toxic
effect on the liver and kidney of experimental mice. Continuous consumption of these plants could
therefore have pathological effects on the consumers. Hence, this show the need for more research in
order to identify lead compounds in indigenous antimalarial plants with less or no toxicity.
Key words: Survey, ethnobotanical, antimalarial, herb.
INTRODUCTION
Malaria is one of the major tropical parasitic diseases
responsible for significant morbidity and mortality
especially among children and pregnant women. It is
estimated that 1 - 2 million people die yearly as a result of
malaria (Sudhanshu et al., 2003). Africa faces the
greatest impact of this disease (Parija, 2008). Malaria is
becoming more resistant to a number of current drugs
and is on the increase because of the global warming
process (Martin and Lefebvre, 1995). Thus, many com-
munities who live in endemic areas, have started to look
for malaria remedies in plants in their local environments
(Miliken, 1997). It is believed strongly that if the herbs
used to treat malaria by our ancestors in Africa hundred
of years ago were not effective, malaria would have
destroyed Africa. More so, Missionaries that came to
Africa would not have met a single person on the
continent of Africa (Elujoba, 2005). The two main groups
of modern antimalarial drugs – artemisinin and quinine
derivatives are known to have their source from herbs.
*Correspondence author. E-mail: tomiwo2@gmail.com
Studies have documented over 1,200 plant species from
160 families used in the treatment of malarial or fever
(Willcox and Bodeker, 2004). Ethnobotanical survey is an
important step in the identification, selection and
development of the therapeutic agents from medicinal
plants. In ethnobotany and natural products chemistry,
the mode of preparation and administration of herbal
preparations are often crucial variables in determining
efficacy in pharmacological evaluation (Levine, 1981;
Lewis et al., 1998; Albers–Schonberg et al., 1997). In
Southwestern Nigeria, studies have been carried out to
document utilization of phytomedicines for treatment of
fevers (Ajaiyeoba et al., 2003). Etkin (1997) also docu-
mented antimalarial plant used by the Hausa in Northern
Nigeria. But these plants are taken orally by indigenes
without any consideration of possible toxic effect of
components in such plants. There is no record of the indi-
genous antimalarial herbs commonly used in Ogun State,
their modes of preparation and consumption pattern.
The objective of the present study was to obtain
information on the use of herbs in the treatment of
malarial fever, the plant part(s) used, method of preparing
herbal antimalarial remedies and how it is administered.

056 Afr. J. Pharm. Pharmacol.
The overall contribution is to document potential
antimalarial herbs from the Nigerian flora.
MATERIALS AND METHODS
Study areas
The study was conducted in the Southwest of Nigeria. A total of 17
communities were visited consisting of 6 urban and 11 rural com-
munities from 3 local government areas (Odeda, Abeokuta South
and Sagamu Local Government Areas (LGAs).
Odeda local government is a rural community. The residents are
mostly farmers. Majority of the town lacks the usual social amenities
and has a low – density population. The community links Ogun
State to Oyo state. Abeokuta South and Sagamu Local Govern-
ment Areas on the other hand, are communities of civil servants
and traders, and densely populated. The community has social
amenities such as electricity supply and pipe borne water. The
residents of these areas belong majorly to the Yoruba ethnic group.
Informed consent
The purpose of the study was explained to the local traditional herb
sellers, farmers, mothers and community and opinion leaders in the
local government areas. Consent to conduct the study was given by
the traditional herbs sellers and community leaders. Informed con-
sent was obtained from each of the participants. An approval for the
study was obtained from the traditional heads of the communities.
General questionnaire
A semi – structured questionnaire was administered randomly to
farmers, mothers, herb sellers, community leaders and elders in the
community to obtain information on commonly used herbs and
parts frequently used for antimalarial remedies. Questions on
methods of herbal preparation, method of administration and
duration of use were also asked.
Sampling method
The study covered a period of three months from March 2008 to
June 2008. Systematic random sampling method was employed in
which only odd numbered respondents were chosen.
Data analysis
Data obtained from the questionnaires were entered into the
computer and analysed using Epi6-info version 6.04 (CDC, Atlanta
GA, USA) (Dean et al., 1994).
RESULT
Demography
A total of 104 randomly selected respondents were
interviewed which include farmers, mothers, herb sellers,
community leaders and elders. The ages of respondents
ranged between 40 – 90 years. Majority of the respon-
dents were females (64.42%) including mothers, herb
sellers and farmers, while the males (35 – 58%) were
community leaders, elders and farmers (Table 1).
Table 1. Demography structure of survey
respondents showing age and sex.
Age (Years) N (%)
40-50 21 (20.2)
51-60 26 (25.0)
61-70 33 (31.7)
71-80 18 (17.3)
81-90 6 (5.8)
Total 104
Sex N (%)
Male 37 (35.58)
Female 67 (64.42)
Total 104
The plant parts frequently used and mentioned in this
study are stated in Table 3. The frequency of occurrence
of various herbs mentioned during the botanical survey is
presented in Table 2. The most commonly mentioned
plants were Morinda lucida (7.87%), Lawsonia inermis
(7.41%), Citrus medica (6.94%), Sarcocephalus latifolius
(6.48%) and Celastrus indica (6.43 %). Among the top
frequently mentioned plants, three plants belong to the
family RUBIACEAE (Morinda lucida, Rytigynia nigerica
and S. latifolius). Other families in this category are
Anarcardiaceae, Zingibercenae, Compositae, Apocyn-
aceae, Fabaceae and Meliaceae. Level of toxicity was
based on reports of documented studies.
Herbal preparation
Herbal remedies can either be prepared from dry plant
“ingredients” or freshly collected samples from the field.
Respondents however affirmed that either plant material
is efficient depending on accessibility to plant species as
some plants are not easily seen within the locality.
Hence, they are collected fresh or bought and preserved
dry. In rural communities, it is common practice for
dwellers to prepare herbal remedies in local clay pots.
This is strongly preferred to aluminum pots.
Arrangement of plant part(s) ingredient
When remedies consisted of more than 2 plant parts and
recipes, seeds, fruits and stem barks were placed at the
bottom of the cooking pots followed by the fragile part like
leaves on the top.
Traditional solvent of choice
The various solvents for herbal preparations mentioned
are water, aqueous extract from fermented maize and
alcohol.

Idowu et al. 057
Table 2. Responses on common antimalarial plants and parts used in Ogun State.
S/N Vernacular name Botanical name Plant pt(s) Frequency (%) Antim. activity Toxicity
1 Oruwo Morinda lucida L. S.B., L. 7.87 Significant Toxic
2 Laali Lawsonia inermis L. L 7.41 Minimal Toxic
3 Osan were Citrus medica L., F. 6.94 Slightly sign. Not toxic
4 Egbesi Sarcocephalus latifolius (Smith) Bruce S.B., L. 6.48 Significant Toxic
5 Ponju owiwi Morinda morindiodes Bark. A.P.,R.B. 6.48 Significant No info.
6 Ewe tea Cymbopogon citrates (DC) Stapf L 6.48 Slightly sign. Not toxic
7 Ahun Alstonia boonei De Wild. S.B., L 5.56 Significant Minimal
8 Awopa Petivera alliacea L. S.B. 4.17 Significant Toxic
9 Mangoro Mangifera indica L. S.B., L 4.17 Significant Minimal
10 Ata ile pupa Zingiber officinale Roscoe. U. S. 3.44 Slightly sign. Negligible
11 Oganwo Khaya grandifolia S.B. 3.32 Significant Minimal
12 Koko Theobroma cacao L. S.B. 3.32 Slightly sign. Minimal
13 Owu Gossypium arboretum L. L 3.32 Slightly sign. Minimal
14 Dangoyaro Azadirachta indica A. Juss L 3.32 Significant Negligible
15 Oparun Bambosa vulgaris L 3.32 No activity Negligible
16 Akintola Chromolaena odorata L. A.P. 2.85 Slightly sign. Not toxic
17 Orinbo arinka Lecaniodiscus cupanioides Planch. L., S.B. 2.85 Slightly sign. Toxic
18 Orogbo Garcinia kola (Heckel) S.B. 1.39 Slightly sign. Toxic
19 Goba Psidium guajava L. L 1.39 Minimal Minimal
20 Aridan tooro Cassia fistulosa Lam. S.B 1.39 Slightly sign. Minimal
21 Efinrin Ocimum gratissium L 1.39 Minimal Negligible
22 Furuntu Terminalia catappa L. L 1.39 No info. No info.
23 Otili Cajanus cajan Millsp. L 1.39 Significant Not toxic
24 Alubosa Allium cepa L. L., S. 1.39 Minimal Not toxic
25 Elegun oko Rytigynia nigerica (S.Moore) R.B. 1.39 Minimal Minimal
26 Ehin olobe Phyllantus amarus L 0.93 Slightly sign. Not toxic
27 Afon Treculia Africana De Wild. S.B. 0.93 Minimal Minimal
28 Ewuro Vernonia anygdalina Del. L 0.93 Significant Negligible
29 Asofeyeje Rauvolfia vomitoria Afzel. L 0.93 Slightly sign. Negligible
30 Ibepe Carica papaya L. L 0.93 Minimal Minimal
31 Mafowokon Argermone mexicana Linn. L 0.46 Significant Toxic
32 Irosu Baphia nitida Lodd. S.B., L 0.46 No info. Not toxic
33 Atare Aframonium melegueta S.B 0.46 No info. Not toxic
34 Piya Persea americana S.B., L 0.46 No info. Toxic
35 Olorin Xylopia aethiopica Dunal. Seed 0.46 Minimal Toxic
36 Ponhan Lophira alata S.B. 0.46 Minimal Toxic
37 Oju ologbo Abrus precatorius L. L 0.46 Minimal Toxic
38 Iyeye Spondias mombin L., S.B. 0.46 Minimal Not toxic
L- leaf, S.B- stem bark, R.B- root bark, A.P- aerial parts, U.S- underground stem, No info.- no information, Freq.- frequency. Toxicity of plants as reported by
Ajaiyeoba et al. (2006); Davis (1978); Bird (1991); Robert (2009); Uko et al. (2001); Yemitan and Adeyemi (2005); Aguwa (1987); Oze et al. (2007); Adedapo
et al. (2005); Bakhiet and Adam (2004); U.S. Department of Health and Human Services (2006); Raintree Nutrition (2008).
A higher percentage of those interviewed especially in
rural communities showed preference to aqueous extract
from fermented maize (98%) followed by water (90%)
and alcohol (20%) (Figure 1). This notion was further
confirmed in the interview with herbs sellers in urban
communities. All the respondents generally believe that
alcohol is only used for the preparation of remedies
consisting mainly hardy plant parts like stem bark, root
and seeds.
Traditional extraction methods
The two main preparation methods are boiling in water or
aqueous extract from fermented maize and steeping/
soaking in the solvents mentioned or alcohol. More

058 Afr. J. Pharm. Pharmacol.
Table 3. Frequency of Plant Parts commonly used for
antimalarial remedy.
Plant part Frequency N (%)
Leaf 120 (71.0)
Stem 81 (48.0)
Root bark 13 (7.6)
Fruits 4 (2.5)
Seed 4 (2.5)
Underground stem 4 (2.5)
Total 226 (134.1)
0
20
40
60
80
100
120
Fermented Maize
Water
Water Alcohol
Solvent of extraction
Perce nta g e of r e spo nde nts
Figure 1. Medium of herbal extraction as commonly used by respondents.
preference was shown to boiling than soaking. Boiling is
usually done using either water or aqueous extract from
fermented maize starch but more preference was given
to aqueous extract from fermented maize as this is
believed to be more efficient. Alcohol was never used as
solvent when boiling herbal “ingredients”. Duration of
boiling ranged from 1 - 2 h on burning fire wood or
cooking stove till a change in color of the solvent is
observed indicating “full dissolution of active ingredients
into the solvents” as some stated.
Soaking, a second choice of preparation was given less
preference unlike boiling.
Solvents used can either be water, aqueous extract from
fermented maize or alcohol. This method is preferred by
its users as they believe that the ingredients will be
extracted without the “ingredients” from the plant been
exposed to heat which they believe could somehow have
effect on the efficacy of the herbal recipes. Plant part are
cut into small piece and soaked in corked bottles or
containers for 2 to 3 days.
Soaked herbal remedies are always available in house-
holds irrespective of obvious symptoms of malaria and
most times are used for prophylactics than treatments.
Method of administration
All the respondents preferred drinking a cup-full (about 5
cl) of aqueous alcoholic preparations 2 to 3 times daily or
as much as possible till symptoms of malaria disappear.
About 40% of respondents suggested bathing and steam
inhalation of the aqueous preparations for 4 – 10 days
especially when high fever is observed in patients. It was
also observed that majority of those interviewed use
antimalarial herbal remedies as prophylactics and the
frequency of consumption depends on the severity of
infection.
DISCUSSION
From the list of herbs frequently used and the plant parts
in Table 1, M. lucida is a widely known plant possessing
antimalarial properties attributed to anthraquinones and
anthranquinols isolated from the plant. (Koumaglo et al.,

1992; Sittie et al., 1999; Adewunmi and Adesogan,
1984). L. inermis is also used by some respondents as
‘blood tonic’, thus believing that it has a dual effect.
Studies also confirmed that S. latifolius, Alstonia boonei,
Petivera alliacea, Mangifera indica and Khaya grandifolia
have significant antimalarial properties (Guede et al.,
2005; Awe et al., 1998; Pedro and Antonio, 2001;
Agbedahunsi et al., 1998), but little is known about
Morinda morindiodes which was also frequently
mentioned and has a frequency of 6.48% as shown in
Table 1. The combination of different plants and parts in
the preparation of antimalarial herbal remedy is not
uncommon among respondents and it is believed that
some plants enhance the action of other herbs. This can
indicate an increase on permeability of the Plasmodium
membrane to antiparasitic substances or an inhibition of
pump mechanism of eliminating the drugs (Alexandros,
2007).
The use of either freshly collected herbal recipes or
preserved (dry) plant parts seems not to make any
difference in its perceived efficacy to the respondents.
This was confirmed in the study as respondents showed
no peculiar preference to one. However, studies had
shown that there were quantitative and qualitative
differences in the essential oil components of fresh and
dry plant materials (Okoh et al., 2008; Fatemeh et al.,
2006) Thus, dry plant materials might not be as potent as
freshly collected herbs. Pharmacological laboratory
studies have also employed the drying of plant parts
during the preparation of plant extracts.
There is no scientific reason backing the preference to
the use of clay pots for herbal preparations, but some of
the respondents said that preference is given to the use
of clay pots because clays pots have been in use before
the advent of aluminum pots and even cheaper than
aluminum pots.
Respondents also showed preference for the arrange-
ment of plants parts in cooking pots although this has not
been studied in relation to plant / herb efficacy. However,
respondents believe that plant ‘ingredients’ are soaked
better in that arrangement especially when boiling is to be
employed.
Preference for solvent of herbal remedy is because of
the belief that some solvents are efficient than others and
depending on the plant parts. However, aqueous extract
form fermented maize was shown more preference than
water and alcohol. Laboratory studies had also confirmed
the efficacy of one solvent over another as solvent of
extraction in relation to the antimalarial property of the
plant. For example, the methanolic extracts of Flueggea
virosa, Maytenus undata and Maytenus putter lickioides
had higher percentage of chemosuppression of parasi-
taemia in vivo than the water extract of the plants. While
the water extracts of Harungana madagascariensis and
Warburgia stuhlmannii had higher chemosuppression of
parasitaemia than the methanolic extracts in vivo (Muthaura
et al., 2007).
Boiling as a method of preparation was frequently men-
Idowu et al. 059
tioned than soaking (Figure 1). This is partly because of
the choice of solvent and the type of plant parts to be
used in preparing the herbal remedy. From this study, it
was also observed that the dose of the herbal remedy
used is dependent on disappearance of symptoms of
malarial fever. Most of the respondents believe that
herbal remedies can be consumed as much as possible,
even as prophylactics but they are ignorant of the toxic
affects of most of these herbs. Studies had however
proved that some antimalarial herbs have dose
dependent effect, for example high levels of chemosup-
pression were produced at high doses of the leaf and
root-bark extracts of Vernonia amygdalina (Abosi and
Raseroka, 2003). Studies had also shown that some
plants are highly toxic despite their high chemosup-
pression of parasitaemia. Morinda lucida for example,
which is top on the list of frequently used plants was
observed for its in vitro cytotoxicity and the stem bark
was found to be extremely toxic (Ajaiyeoba et al., 2006).
The seeds of Lawsonia inermis have also been found to
be toxic in molluscs (Singh and Singh, 2001). However,
our search on published studies on the level of antima-
larial activity and toxicity of the 38 plants in this study
showed that 80% have been documented to have
antimalarial property but suppressive and none
clearance, while about 65% have toxic effects. Extract of
the stem bark of Alstonia boonei could be potentially
nephrotoxic especially when dose is high and duration of
use extended (Panda, 1999). The toxicity of S. latifolius is
moderately high while Cymbopogon citratus is
insignificant respectively (Iwu, 1993).
Conclusion
This study and similar studies shows the need for the
enlightenment of traditional medicine practitioners and
the public in general on selective use of herbs for the
treatment of malaria.
However, study on the effectiveness of aqueous extract
from fermented maize (as observed in practice) as
solvent of extraction in laboratory test extracts had not
been documented.
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