Ethnobotanical studies of medicinal plants used by Traditional Health Practitioners in the management of diabetes in Lower Eastern Province, Kenya

Abstract

Diabetes mellitus is a growing problem in many developing countries and the financial burden associated with it is enormous. In traditional African communities, majority of people relies on traditional medicines and Traditional Health Practitioners as the primary source of health care. Hence, this study was undertaken in the Lower Eastern province of Kenya to document the medicinal plants used by the traditional practitioners to treat diabetes and to assess the existing knowledge in management of this condition.
Data was collected using structured open- and close-ended questionnaires.
Thirty-nine species belonging to 33 genera and 26 families were encountered and the most frequently cited species were from Caesalpiniaceae, Ebenaceae, Solanaceae and Labiatae families. Twenty-eight percent of the plant species are reported to have hypoglycaemic activity.
Currently there is no data on medicinal plants used to treat diabetes in Kenya. Therefore, these findings are important in the management of diabetes and future research on traditional medicine in drug development.

Full text

Journal
of
Ethnopharmacology
139 (2012) 74–
80
Contents
lists
available
at
SciVerse
ScienceDirect
Journal
of
Ethnopharmacology
j
o
ur
nal
homep
age
:
www.elsevier.com/locate/jethpharm
Ethnobotanical
studies
of
medicinal
plants
used
by
Traditional
Health
Practitioners
in
the
management
of
diabetes
in
Lower
Eastern
Province,
Kenya
Lucia
K.
Ketera,∗,
Patrick
C.
Mutisob
aKenya
Medical
Research
Institute,
Centre
for
Traditional
Medicine
and
Drug
Research,
Mbagathi
Road,
P.O.
Box
54840-00200,
Nairobi,
Kenya
bUniversity
of
Nairobi,
School
of
Biological
Science,
P.O.
Box
30197-00100,
Nairobi,
Kenya
a
r
t
i
c
l
e
i
n
f
o
Article
history:
Received
26
May
2011
Received
in
revised
form
7
October
2011
Accepted
9
October
2011
Available online 14 October 2011
Keywords:
Traditional
Health
Practitioners
Diabetes
mellitus
Medicinal
plants
Ethnobotanical
survey
Kenya
a
b
s
t
r
a
c
t
Ethnopharmacological
relevance:
Diabetes
mellitus
is
a
growing
problem
in
many
developing
countries
and
the
financial
burden
associated
with
it
is
enormous.
In
traditional
African
communities,
majority
of
people
relies
on
traditional
medicines
and
Traditional
Health
Practitioners
as
the
primary
source
of
health
care.
Hence,
this
study
was
undertaken
in
the
Lower
Eastern
province
of
Kenya
to
document
the
medicinal
plants
used
by
the
traditional
practitioners
to
treat
diabetes
and
to
assess
the
existing
knowledge
in
management
of
this
condition.
Materials
and
methods:
Data
was
collected
using
structured
open-
and
close-ended
questionnaires.
Results:
Thirty-nine
species
belonging
to
33
genera
and
26
families
were
encountered
and
the
most
frequently
cited
species
were
from
Caesalpiniaceae,
Ebenaceae,
Solanaceae
and
Labiatae
families.
Twenty-eight
percent
of
the
plant
species
are
reported
to
have
hypoglycaemic
activity.
Conclusions:
Currently
there
is
no
data
on
medicinal
plants
used
to
treat
diabetes
in
Kenya.
Therefore,
these
findings
are
important
in
the
management
of
diabetes
and
future
research
on
traditional
medicine
in
drug
development.
© 2011 Elsevier Ireland Ltd. All rights reserved.
1.
Introduction
Diabetes
is
a
major
public
health
problem
currently
affecting
284.6
million
people
worldwide
and
according
to
the
latest
Inter-
national
Diabetes
Federation
estimates
it
is
expected
to
affect
438.4
million
adults
by
2030
becoming
one
of
the
world’s
main
disabler
and
killer
(IDF,
2009).
The
major
part
of
this
numerical
increase
will
occur
in
developing
countries
like
Kenya
due
to
population
ageing,
obesity
and
increase
in
sedentary
lifestyle
(IDF,
2009;
Wild
et
al.,
2004).
In
Sub-Saharan
Africa,
the
current
adult
diabetes
prevalence
stand
at
12.1
million
and
is
projected
to
rise
to
23.9
million
by
2030
(IDF,
2009).
This
proportion
is
more
than
double
the
pre-
dicted
global
increase
of
37%.
In
Kenya,
diabetes
prevalence
ranges
between
2.7%
in
rural
areas
and
10.7%
in
urban
areas
(Daily
Nation,
2010).
The
vast
majority
(90–95%)
of
diabetes
cases
fall
into
type
2
(American
Diabetes
Association,
2005)
and
the
clinical
treatment
for
type
2
targets
both
insulin
deficiency
and
resistance
and
more
recently
the
prevention
of
pancreatic
␤-cell
function
decline.
More
than
80%
of
the
population
in
Sub-Saharan
Africa
relies
on
traditional
medicines
and
Traditional
Health
Practitioners
(THPs)
as
the
primary
source
of
health
care
(WHO,
2002)
due
to
accessibil-
ity
and
cultural
acceptance.
In
Kenya,
several
medicinal
plants
are
∗Corresponding
author.
Tel.:
+254
20
2722541;
fax:
+254
20
2720030.
E-mail
addresses:
lketer@kemri.org,
lketer@yahoo.co.uk
(L.K.
Keter).
used
traditionally
to
treat
diabetes
according
to
oral
communica-
tion
with
THPs
visiting
Centre
for
Traditional
Medicine
and
Drug
Research
(CTMDR),
Kenya
Medical
Research
Institute
(KEMRI).
However,
information
on
local
medicinal
plants
used
tradition-
ally
in
Kenya
for
the
management
of
diabetes
mellitus
is
scarce.
Hence,
documentation
of
plants
used
to
treat
diabetes
and
evalu-
ation
of
the
traditional
practitioners’
understanding
of
the
causes
and
symptoms
of
diabetes
is
critical
for
proper
management.
This
study
was
therefore
carried
out
among
THPs
residing
in
Machakos
and
Kangundo
Districts
in
Machakos
County,
Kenya
to
assess
tra-
ditional
knowledge
on
diabetes
and
to
document
medicinal
plants
used
to
treat
this
condition.
2.
Methods
2.1.
Study
area
The
study
was
carried
out
in
the
districts
of
Kangundo
and
Machakos,
on
the
Lower
Eastern
Province
of
Kenya.
Lower
East-
ern
Province
is
principally
inhabited
by
the
Kamba
community
who
speak
Kikamba.
Administratively,
the
Lower
Eastern
Province
is
fur-
ther
divided
into
three
County
governments:
Kitui,
Machakos
and
Makueni
and
according
to
the
2009
National
Census,
Machakos
County
had
a
population
of
1,098,584
(Kenya
National
Bureau
of
Statistics,
2009).
The
two
study
sites
were
selected
based
on
exten-
sive
utilization
of
Traditional
Medicines
by
the
community
in
these
0378-8741/$
–
see
front
matter ©
2011 Elsevier Ireland Ltd. All rights reserved.
doi:10.1016/j.jep.2011.10.014

L.K.
Keter,
P.C.
Mutiso
/
Journal
of
Ethnopharmacology
139 (2012) 74–
80 75
districts.
Also
Kangundo
and
Machakos
Districts
provided
both
the
urban
and
rural
setup
and
its
proximity
to
Kenya’s
capital
city,
Nairobi,
makes
them
even
more
suitable.
2.2.
Data
collection
Ethnobotanical
approach
was
used
to
explore
the
knowledge,
diagnosis
and
treatment
practices
of
diabetes
by
the
Traditional
Health
Practitioners
(THPs).
A
guided
questionnaire
interview
was
administered
to
participating
THPs
who
were
identified
with
the
help
of
the
local
provincial
administration
officers
(Chief)
and
a
social
scientist.
On
the
appointed
interview
day,
the
THPs
assem-
bled
at
the
nearest
local
provincial
offices.
Each
THP
was
then
interviewed
alone
to
maintain
confidentiality
among
them.
The
interviews
educed
information
on
the
socio-demographic
infor-
mation
of
the
interviewees
such
as
age,
school
attendance
and
occupation,
the
causes
and
diagnosis
of
diabetes,
medicinal
plants,
vernacular
names,
parts
used,
source
of
the
plant
materials,
meth-
ods
of
preparation,
routes
of
administration,
duration
of
treatment
and
contraindications
in
traditional
treatment
of
diabetes.
The
medicinal
plants
mentioned
by
the
interviewees
were
identified
in
the
field
by
a
botanist
from
the
University
of
Nairobi.
Voucher
speci-
mens
of
each
plant
species
reported
were
collected
for
confirmation
and
are
deposited
at
the
University’s
Herbarium.
2.3.
Study
approval
Ethical
approval
for
this
study
was
granted
by
the
KEMRI
SSC
and
ERC
(SSC
No.
1145).
Before
the
interview
was
carried
out,
the
objectives
of
the
study
and
the
planned
use
of
the
information
were
explained
to
the
THP.
Permission
was
then
sought
and
written
consent
obtained
in
all
cases.
3.
Results
3.1.
Interviewees’
socio-demographic
characteristics
Twenty-eight
THPs
were
interviewed
(19
male,
9
female)
(Table
1).
The
mean
age
was
47.8
±
15.1
years
for
male
THPs
and
67.6
±
14.4
years
for
female
THPs.
The
majority
of
the
interviewees
had
attained
primary
level
of
education
(39.3%)
and
secondary
level
(21.4%)
while
17.8%
had
no
formal
education.
Most
of
those
with-
out
formal
education
were
women.
Ten
(35.7%)
of
the
interviewees
engaged
in
peasant
farming
as
their
source
of
livelihood
while
7
(25%)
practiced
as
herbalists
as
the
primary
occupation
(mostly
men).
The
primary
occupation
for
the
female
interviewees
(6
out
of
8)
was
peasant
farming.
3.2.
Traditional
knowledge
and
practice
Seventy-nine
percent
of
the
THPs
interviewed
acquired
the
tra-
ditional
medical
knowledge
from
members
of
the
family
mainly
grandparents
and
parents
(8
out
of
9
female
and
14
out
of
19
male
interviewees),
14%
through
apprenticeship
(4
male
interviewees)
and
7%
(1
male
and
1
female
interviewee)
through
dreams/or
God.
Most
of
the
interviewees
had
over
11
years
of
practice
with
35.7%
having
practiced
for
between
1
and
10
years,
39.3%
for
11–20
years,
17.9%
for
21–30
years
while
7.1%
had
over
41
years
of
practice.
Majority
(71.4%)
of
those
interviewed
were
practicing
from
their
residences/houses
while
14.3%
had
clinics
and
another
14.3%
were
consulting
at
the
market
place.
Only
four
(all
male)
of
the
inter-
viewees
had
their
practice
recognized
by
the
government
with
registration
from
the
Ministry
of
National
Heritage
and
Culture
while
12
out
of
28
were
affiliated
to
Traditional
Health
practition-
ers’
association.
Table
1
The
socio-demographic
characteristics
of
the
interviewees
(n
=
28).
Characteristic
Number
of
interviewees
Total
percentage
Male
Female
Sex
Male 19 67.9
Female 9 32.1
Age
(years)
20–30
3
0
10.7
31–40
3
1
14.3
41–50
6
0
21.4
51–60
2 1 10.7
61–70
4 2 21.4
≥71 1
5
21.4
Education
level
Nil/none 1
4
17.8
Adult
education
0
1
3.6
Primary
8
3
39.3
Secondary
6
0
21.4
Tertiary
colleges
3
1
14.3
University
1
0
3.6
Primary
occupation
Peasant
farmer
4
6
35.7
THP 6
1
25.0
Nurse
0
1
3.6
Driver
1
0
3.6
Laboratory
technologist
3
0
10.7
Business
3
1
14.3
Mason 1 0
3.6
Agricultural
extension
officer
1
0
3.6
Secondary
occupation
Peasant
farmer
4
0
14.3
THP
13
8
75.0
Business 2 1 10.7
3.3.
Traditional
Health
Practitioners’
knowledge
of
diabetes
The
interviewees
had
good
knowledge
of
diabetes
on
the
basis
of
acceptable
clinical
symptoms
such
as
smelly
breath
(4),
frequent
thirst
(7),
frequent
urination
(7),
body
weakness
(fatigue)
(4)
and
smelly
urine
(2).
Fainting
and
swollen
diaphragm
were
each
cited
by
three
interviewees
while
white
foamy
urine,
fast
heart
beat
and
backache
were
each
mentioned
by
one
interviewee.
Five
of
the
interviewees
had
no
idea
on
the
signs
and
symptoms.
However,
10
interviewees
acknowledged
relying
on
laboratory
or
hospital
report
and
three
on
patient
confession.
The
interviewees
believed
that
the
causes
of
diabetes
included
consumption
of
alcohol
(2),
sugary
foods
and
beverages
(10)
and
eating
of
fatty
foods/or
food
related
(9).
Red
meat,
salt,
contaminated
water
and
acid
in
the
diaphragm
are
other
causes
that
were
each
indicated
by
one
inter-
viewee.
Three
of
the
interviewees
associated
diabetes
to
family
history
while
two
associated
it
with
stress.
Six
(21%)
interviewees
did
not
know
the
possible
causes
of
diabetes
mellitus.
3.4.
Plant
species
used
to
treat
diabetes
mellitus
Thirty-nine
plant
species
distributed
between
33
genera
and
26
families
were
reportedly
used
in
herbal
preparations
for
the
treatment
of
diabetes
mellitus
by
the
interviewees.
Five
of
these
species
could
not
be
identified
to
species
level
due
to
lack
of
reproductive
features.
Table
2
shows
the
plant
species,
the
ver-
nacular
names,
the
parts
used,
the
number
of
interviewees
citing
each
species
and
mode
of
preparation.
The
families
with
the
most
reported
plant
species
were
Caesalpiniaceae
with
4
species:
Ebe-
naceae,
Solanaceae
and
Labiatae
families
had
3
species
each
while
Euphorbiaceae,
Cucurbitaceae,
Oleaceae
and
Passifloraceae
had
2
species
each
and
the
rest
had
one
species
each
(Table
2).
The
most
frequently
mentioned
medicinal
plants
were
Cassia
abbreviata
Oliv.,
Zanthoxylum
chalybeum
Engl.,
Momordica
foetida

76 L.K.
Keter,
P.C.
Mutiso
/
Journal
of
Ethnopharmacology
139 (2012) 74–
80
Table
2
Plant
species
reported
by
the
Traditional
Health
Practitioners
for
the
management
of
diabetes.
Scientific
name
Family
Local
name
(Kamba)
Collection
number
Part
used
Number
of
interviewees
citing
species
Mode
of
preparation
Tamarindus
indica
Linn. Caesalpiniaceae Kithumula
LKP
2010/003
RB/Fr
3
Decoction
Strychnos
henninggsii
Gilg. Loganiaceae
Muteta
LKP
2010/004
L
1
Decoction
Euclea
divinorum
Hiern.
Ebenaceae
Kikuthi/Mukinyei
LKP
2010/001
RB
4
Decoction
Momordica
foetida
Schumach.
Cucurbitaceae
Iphunzu
LKP
2010/002
L
5
Decoction
Cassia
abbreviata
Oliv.
Caesalpiniaceae
Malandesi
LKP
2010/005
L/Pods
7
Decoction
Zanthoxylum
chalybeum
Engl.
Rutaceae
Mukenea
LKP
2010/006
SB
6
Decoction/hot
infusion
Urtica
massaica
Mildbr. Urticaceae Kinyeleelya LKP
2010/010 L
5
Decoction
of
pounded
leaves
Ajuga
remota
Benth.
Labiatae
Wanjiru
wa
Rurii
LKP
2010/009
L/WP
4
Decoction
Aspilia
pluriseta
Schweinf
Compositae
Muti/Wuti
LKP
2010/008
L
2
Decoction
Fuerstia
africana
T.C.E.
Fries
Labiatae
Kalaku
LKP
2010/007
Aerial
parts
1
Decoction
Clerodendrum
myricoides
(Hochst.)
Vatke
Verbenaceae
Muvweia/Munguya
LKP
2010/011
L
1
Decoction
Ficus
natalensis
(Miq.)
Hochst.
Moraceae
Muuomo/Kiumo
LKP
2010/015
Fr
1
Cold
infusion
Azardiracta
indica
A.
Juss.
Meliaceae
Mwarubaine
LKP
2010/012
SB/L
6
Decoction
Cactus
spp. Cactaceae Matomoko Not
Collected L 6
Squeeze
juice
from
fresh
leaves
Bersama
abyssinica
Fres.
Melianthaceae
Mukilyulu
LKP
2010/017
RB
2
Decoction
Passiflora
spp.
passifloraceae
Makundi
Not
Collected
L
2
Decoction
Eucalyptus
spp.
Myrtaceae
Musanduku
Not
Collected
SB
4
Decoction
Aloe
spp.
Aloeaceae
Kiluma
Not
Collected
L
2
Leaves
gel
Allium
sativum
L. Alliaceae Kitunguua
kinene LKP
2010/014 Bulb
3
Hot
infusion
of
pounded
bulb
Terminalia
brownii
Fres. Combretaceae
Muuuku/Kiuuku
LKP
2010/016
SB
1
Decoction
Croton
megalocarpus
Hutch.
Euphorbiaceae
Muthulu/Kithulu
LKP
2010/018
L
1
Decoction
Senna
singueana
(Del.)
Lock
Caesalpiniaceae
Mukengeka
LKP
2010/013
L
4
Decoction
Solanum
incanum
L. Solanaceae Mukondu/Mutungu LKP
2010/022 L 2
Decoction
Senna
didymobotrya
(Fres.)
I.
&
Bar.
Caesalpiniaceae
Muthaa/Ithaa
LKP
2010/019
L
3
Hot
infusion
Steganotaenia
araliacea
Hoch.
Umbelliferae
Muvuavui
LKP
2010/023
L
1
Decoction
Ormocarpum
kirkii
S.
Moore Leguminosae
Muthii
LKP
2010/024
L
2
Decoction
Ocimum
basilicum
L.
Labiatae
Mutaa
LKP
2010/021
WP/L
2
Pounded
leaf
cold
infusion/Decoction
Oxygonium
sinuatum
(Meisn.)
Dammer
Polygonaceae
Song’e
LKP
2010/020
WP
1
Cold
infusion
of
pounded
whole
plant
Passiflora
subpeltata
Passifloraceae
Makundi
LKP
2010/025
L
1
Decoction
Withania
somnifera
(L.)
Dunal
Solanaceae
Mwianzo
LKP
2010/026
R
2
Cold
infusion
Solanum
renschii
Vatke
Solanaceae
Mukonda
Kondu
LKP
2010/027
R/L
1
Decoction
Abrus
precatorius
L. Papilionaceae Kyuma
Kyamditi LKP
2010/028 L
1
Decoction
Momordica
spp.
Cucurbitaceae
Iphunzu
Not
Collected
L
3
Decoction
Euclea
natalensis
A.
DC Ebenaceae
Mukinyei
LKP
2010/029
R
1
Decoction
Euclea
racemosa
Murr.
Ebenaceae
Mukinyei
LKP
2010/030
L/SB/RB
2
Decoction
Schrebera
alata
(Hochst.)
Welw.
Oleaceae
Mutoma
LKP
2010/031
SB/R/L
1
Cold
infusion
Garcinia
buchananii
Bak.
Guttiferae
Mukanga
LKP
2010/032
SB
1
Decoction
Olea
europaea
L.
Oleaceae
Molialundi
LKP
2010/033
SB/R
1
Decoction
Croton
macrostachyus
Del.
Euphorbiaceae
Mutundu/Kitundu
LKP
2010/034
RB
1
RB:
root
bark,
L:
leaves,
SB:
stem
bark,
WP:
whole
plant,
R:
whole
root,
and
Fr:
fruit.
Schumach.,
Urtica
massaica
Mildbr.
and
Azadirachta
indica
A.
Juss.
(Table
2).
Other
medicinal
plants
that
were
mentioned
by
at
least
four
respondents
were
Senna
singueana
Del.,
Ajuga
remota
Benth.,
Eucalyptus
spp.
and
Euclea
divinorum
Hiern.
Interviewees
reported
that
the
appropriate
plant
parts
were
collected
when
needed
with-
out
any
time
specification.
The
herbal
medicines
were
mainly
prepared
as
decoctions
which
were
orally
given
(Table
2).
It
was
noted
that
some
plant
species
shared
vernacular
names
(Table
2).
Mukinyei
could
be
referring
to
Euclea
divinorum,
Euclea
natalensis
or
Euclea
racemosa.
Any
passiflora
was
referred
to
as
Makundi
and
Momordica
spp.
as
Iphunzu.
3.5.
Plant
parts
used
The
leaves
were
the
most
frequently
used
plant
parts
(48%)
fol-
lowed
by
the
stem
bark
(16%),
roots
and
root
bark
(10%)
while
the
fruits,
whole
plant,
and
aerial
parts
accounted
for
less
than
10%
each
(Fig.
1).
3.6.
Medicine
preparation
and
administration
The
medicines
were
processed
mainly
as
mixtures
of
two
or
more
plant
species
in
the
form
of
concoctions.
To
prepare
a
con-
coction,
plant
parts
are
obtained
from
more
than
one
plant
species
and
boiled
together
in
water.
Some
of
the
commonly
cited
mix-
tures
included:
Zanthoxylum
chalybeum,
Momordica
foetida
and
Cassia
abbreviata;
Croton
megalocarpus,
Ormocarpum
kirkii
and
Senna
singueana;
Solanum
incanum,
Ocimum
basilicum
and
Senna
singueana;
Azadirachta
indica,
Zanthoxylum
chalybeum
and
Cas-
sia
abbreviata.
The
method
of
preparation
employed
primarily
for
single
plant
parts
used
were
decoction
(76%)
and
infusion
(20%)
(Table
2).
A
decoction
is
prepared
by
boiling
plant
parts
of
sin-
gle
plant
species
in
water.
Hot
and
cold
infusions
are
prepared
by
soaking
the
plant
parts
in
hot
and
cold
water,
respectively.
These
medicines
were
prepared
when
required,
thus
most
interviewees
did
not
preserve
the
medicines.
The
herbal
medicines
were
admin-
istered
orally
and
the
most
commonly
mentioned
quantities
and

L.K.
Keter,
P.C.
Mutiso
/
Journal
of
Ethnopharmacology
139 (2012) 74–
80 77
Fig.
1.
Proportions
of
plant
parts
reported
to
be
used
in
preparation
of
diabetes
treatment.
frequency
of
administration
were
one
tablespoonful
(10
ml)
three
times
daily
(4),
half
a
cup
(approximately
125
ml)
three
times
daily
(2),
one
cup
(approximately
250
ml)
twice
daily
(9)
and
one
cup
three
times
daily
(11).
The
need
for
treatment
for
4
weeks
was
indicated
by
53.6%
(15)
of
the
traditional
practitioners.
Thirty-nine
percent
(9)
recommended
treatment
for
2–3
weeks
while
only
two
recommended
treatment
for
8
weeks
and
above.
None
of
the
inter-
viewees
reported
any
toxicity
associated
with
their
medications.
However,
interviewees
admitted
to
advising
their
patients
to
avoid
alcohol
(8),
meat
(3),
sugary
foods
(3),
salt
(4),
hard
labour
(3),
sex
(4)
and
mixing
therapies
(3).
3.7.
Relevant
ethno-botanical
use
and
reported
pharmacological
activity
Literature
search
was
conducted
on
the
reported
medicinal
plants
to
find
out
if
they
are
used
traditionally
to
treat
diabetes
mellitus
in
other
cultures.
Eleven
of
the
species
cited
have
been
used
similarly
in
communities
within
Africa
and
Asia
(Table
3).
These
species
include
Tamarindus
indica,
Strychnos
henningsii,
Azadirachta
indica,
Allium
sativum,
Abrus
precatorius,
Withania
som-
nifera,
Solanum
incanum,
Zanthoxylum
chalybeum,
Senna
singueana,
Euclea
divinorum
and
Olea
europaea.
Aloe
and
Eucalyptus
species
have
also
been
used
traditionally
to
treat
diabetes.
The
hypo-
glycaemic
activity
of
some
plants
reported
in
this
study
has
been
validated
experimentally
in
the
in
vivo
and
in
vitro
diabetic
models,
clinical
and
chemical
studies
(Table
3).
These
medicinal
plants
include
Tamarindus
indica,
Momordica
foetida,
Azadirachta
indica,
Allium
sativum,
Abrus
precatorius,
Solanum
incanum,
Ocimum
basilicum,
Withania
somnifera,
Olea
europaea,
Cassia
abbreviate,
Aloe,
Cactus
and
Eucalyptus
species.
4.
Discussion
Diabetes
mellitus
is
a
metabolic
disease
characterized
by
hyper-
glycaemia
resulting
from
defects
in
insulin
secretion,
insulin
action
or
both
(American
Diabetes
Association,
2005).
The
prevalence
of
diabetes
mellitus
is
growing
worldwide
and
in
Kenya,
approxi-
mately
1.5
million
people
are
living
with
diabetes
today
and
it
is
expected
to
rise
to
2
million
by
2030
if
no
interventions
are
put
in
place
(Daily
Nation,
2010).
In
Kenya,
like
in
many
traditional
African
societies,
phytomedicines
play
a
vital
role
towards
the
well-being
of
the
rural
population
and
numerous
medicinal
plants
have
been
described
for
treatment
of
many
diseases
(Kokwaro,
2009).
How-
ever,
there
is
limited
information
on
plants
used
to
manage
diabetes
in
Kenya.
This
ethnobotanical
study
documents
medicinal
plants
used
in
the
treatment
of
diabetes
mellitus
and
the
existing
knowl-
edge
among
traditional
practitioners
in
the
Lower
Eastern
Province
of
Kenya.
The
educational
status
of
both
male
and
female
interviewees
was
very
low.
However,
the
percentage
of
the
males
with
ter-
tiary
education
was
higher
when
compared
with
that
of
the
female
interviewees.
Most
of
the
interviewees
(79%)
inherited
the
prac-
tice
from
their
grandparents
and
parents
but
few
males
learned
it
through
informal
training
and
dreams.
Similar
findings
on
the
traditional
practitioners’
socio-demographic
characteristics
such
as
educational
level,
age
and
the
source
of
the
traditional
knowledge
have
been
reported
in
other
cultures
(Adebo
and
Alfred,
2011).
The
interviewees
were
found
to
have
some
knowledge
of
dia-
betes
mellitus
based
on
their
ability
to
recognize
a
number
of
symptoms
characteristic
of
the
disease
such
as
excessive
thirst
and
frequent
urination.
Other
clinical
signs
presenting
in
diabetes
that
were
identified
include
fatigue,
fainting
spells,
general
body
weakness
and
passage
of
urine
which
attracts
bees.
Regardless
of
the
cultural
differences,
this
study
reveals
that
the
THPs
in
the
districts
of
Kangundo
and
Machakos,
Kenya
claim
to
diagnose
diabetes
mellitus
in
their
patients
the
same
way
as
the
THPs
in
Tanzania
and
South
Western
Nigeria
(Abo
et
al.,
2008;
Moshi
and
Mbwambo,
2002).
They
identified
alcohol,
high
fat
diet,
stress
and
family
history
as
some
of
the
predisposing
factors.
The
interviewees
were
generally
aware
of
possible
toxicity
from
phytomedicines,
however,
none
reported
any
toxicity
associated
with
their
medica-
tion.
They
reported
advising
their
patients
against
mixed
therapies
among
others.
Patients
who
continue
to
take
plant
remedies
along
with
conventional
medication
may
experience
adverse
effects
due
to
possibility
of
adverse
interaction
between
the
two
medicaments.
Twenty-eight
percent
of
the
plant
species
cited
in
this
study
have
been
reported
in
other
scientific
studies
to
be
used
tradi-
tionally
to
treat
diabetes
and
related
symptoms.
Tamarindus
indica
(Dieye
et
al.,
2008),
Strychnos
henningsii
(Oyedemi
et
al.,
2010),
Azadirachta
indica
(Abo
et
al.,
2008;
Modak
et
al.,
2007;
Grover
et
al.,
2002),
Allium
sativum
(Ogbera
et
al.,
2010;
Modak
et
al.,
2007;
Grover
et
al.,
2002)
Abrus
precatorius
(Attal
et
al.,
2010,
Abo
et
al.,
2008,
Moshi
and
Mbwambo,
2002),
Withania
som-
nifera
(Modak
et
al.,
2007),
Aloe
spp.
(Tahraoui
et
al.,
2007;
Grover
et
al.,
2002),
Solanum
incanum
L.,
Zanthoxylum
chalybeum,
Senna
singueana
(Moshi
and
Mbwambo,
2002),
Olea
europaea
L.
(Dieye
et
al.,
2008;
Tahraoui
et
al.,
2007)
and
Eucalyptus
spp.
(Tahraoui
et
al.,
2007;
Grover
et
al.,
2002)
have
been
used
to
manage
diabetes
mellitus
in
other
cultures
while
Euclea
divinorum
and
Withania
som-
nifera
are
used
for
general
body
weakness
(tonic)
in
East
Africa
(Kokwaro,
2009).
Though,
Senna
singueana,
Zanthoxylum
chalybeum

78 L.K.
Keter,
P.C.
Mutiso
/
Journal
of
Ethnopharmacology
139 (2012) 74–
80
Table
3
Traditional
uses
of
the
species
reported
in
this
study
and
their
reported
relevant
pharmacological
activity.
Scientific
name
Relevant
reported
traditional
uses
Relevant
pharmacological
activity/chemical
constituents
Tamarindus
indica
Linn.
Leaves,
roots,
bark
and
fruits
used
to
treat
diabetes
in
Senegal
(Dieye
et
al.,
2008)
Antidiabetic
activity
of
aqueous
seed
extracts
(Hamidreza
et
al.,
2010;
Maiti
et
al.,
2004)
Strychnos
henningsii
Gilg.
Used
for
diabetes
in
Southern
Africa
(Oyedemi
et
al.,
2010)
Antioxidant
activity
of
the
aqueous
bark
extracts
(Oyedemi
et
al.,
2010).
Antidiabetic
activity
of
related
species,
Strychnos
pseudoquina
(Honório-Franc¸
a
et
al.,
2008).
Euclea
divinorum
Hiern.
Used
as
a
tonic
in
East
Africa
(Kokwaro,
2009)
No
reports
Momordica
foetida
Schumach.
No
reports
Antidiabetic
effect
of
whole
plant
extracts
(van
de
Venter
et
al.,
2008;
Marquis
et
al.,
1977).
Hypoglycaemic
effect
of
foetidin
(Marquis
et
al.,
1977).
Cassia
abbreviata
Oliv.
No
reports
␣-Glucaosidase
inhibition
and
antioxidant
activities
of
stem
bark
extract
(Shai
et
al.,
2010).
Zanthoxylum
chalybeum
Engl.
Roots
used
to
treat
diabetes
and
related
symptoms
in
Tanzania
(Moshi
and
Mbwambo,
2002)
No
reports
Azadirachta
indica
A.
Juss.
Leaves
and
fruits
used
for
diabetes
(Abo
et
al.,
2008;
Modak
et
al.,
2007;
Grover
et
al.,
2002)
Antihyperglycaemic
and
antioxidant
effect
(Gupta
et
al.,
2004;
Biswas
et
al.,
2002;
Grover
et
al.,
2002).
Cactus
spp.
No
reports
Antidiabetic
activity
of
Prickly
Pear
Cactus
(Opuntia
streptacantha
and
Opuntia
fuliginosa)
(Cefalu
et
al.,
2008;
Trejo-González
et
al.,
1996).
Eucalyptus
spp.
Eucalyptus
spp.
leaf
decoction/infusion
used
for
diabetes
(Tahraoui
et
al.,
2007;
Grover
et
al.,
2002)
Antidiabetic
effect
of
the
leaf
extracts
of
species
Eucalyptus
globulus
(Mahmoudzadeh-Sagheb
et
al.,
2010;
Ahlem
et
al.,
2009;
Grover
et
al.,
2002;
Gray
and
Flatt,
1998;
Swanston-Flatt
et
al.,
1990).
Aloe
spp.
Aloe
vera
Burm.
leaf
exudate/aerial
part
used
for
diabetes
(Tahraoui
et
al.,
2007;
Grover
et
al.,
2002)
Hypoglycaemic
effect
of
leaves
extracts
of
species
Aloe
vera
(Jain
et
al.,
2010;
Kim
et
al.,
2009;
Rajasekaran
et
al.,
2004;
Grover
et
al.,
2002)
Aloe
arborescens
(Beppu
et
al.,
2006)
Aloe
barbadensis
(Grover
et
al.,
2002;
Ajabnoor,
1990).
Allium
sativum
L.
Raw
bulb
used
for
diabetes
(Ogbera
et
al.,
2010;
Modak
et
al.,
2007;
Grover
et
al.,
2002)
Anti-diabetic
effect
reported
(Eidi
et
al.,
2006;
Grover
et
al.,
2002)
S-allylcysteine
sulfoxide,
S-methylcysteine
sulfoxide,
and
diallyl
trisulfide
(Kook
et
al.,
2009).
Senna
singueana
(Del.)
Lock
Roots
used
to
treat
diabetes
and
related
symptoms
in
Tanzania
(Moshi
and
Mbwambo,
2002)
No
reports
Solanum
incanum
L. Roots
used
to
treat
diabetes
in
Tanzania
(Moshi
and
Mbwambo,
2002)
Hypoglycaemic
effects
of
the
fruit
extracts
(Musabayane
et
al.,
2006).
Ocimum
basilicum
L.
No
reports
Antidiabetic
effects
of
alcoholic
leaf
extract
(Vats
et
al.,
2002).
Withania
somnifera
(L.)
Dunal
Used
to
treat
diabetes
in
India
and
as
a
tonic
in
East
Africa
(Modak
et
al.,
2007;
Kokwaro,
2009)
Hypoglycaemic
effect
of
root
and
leaf
extracts
(Udayakumar
et
al.,
2009;
Adallu
and
Radhika,
2000).
Abrus
precatorius
L. Leaves
and
roots
used
to
treat
diabetes
in
S
W
Nigeria
and
Tanzania
(Abo
et
al.,
2008,
Moshi
and
Mbwambo,
2002),
used
as
a
tonic
in
India
(Attal
et
al.,
2010)
Antidiabetic
effects
of
chloroform–methanol
seed
extracts
(Attal
et
al.,
2010).
Olea
europaea
L.
Leaf
decoction
used
for
diabetes
in
some
Africa
countries
(Dieye
et
al.,
2008;
Tahraoui
et
al.,
2007)
Antidiabetic
effect
of
the
alcoholic
leaf
extract
(Eidi
et
al.,
2009).
Polyphenols:
oleuropein
and
hydroxytyrosol
(Poudyal
et
al.,
2010).
and
Euclea
divinorum
have
been
used
in
traditional
medicine
to
treat
diabetes
and
its
related
symptoms,
none
of
these
plants
has
so
far
been
reported
to
have
hypoglycaemic
activity
(Table
3).
Ocimum
sanctum,
a
related
species
to
Ocimum
basilicum
L.,
is
used
tradition-
ally
to
treat
diabetes
(Grover
et
al.,
2002).
Abrus
precatorius,
Garcinia
buchananii
and
Bersama
abyssinica
have
been
used
in
traditional
fork-medicine
as
an
aphrodisiac
while
Clerodendrum
myricoides
has
been
used
to
treat
impotence
(Kokwaro,
2009).
Impotence
is
one
of
the
manifestations
of
autonomic
neuropathy
in
diabetics.
Hence,
the
use
of
the
same
plant
species
in
different
culture
in
the
man-
agement
of
diabetes
strongly
suggests
that
these
species
may
be
effective.
Literature
review
of
the
cited
plants
confirmed
that
Tamarindus
indica
(Hamidreza
et
al.,
2010;
Maiti
et
al.,
2004),
Momordica
foetida
(van
de
Venter
et
al.,
2008;
Marquis
et
al.,
1977),
Azadirachta
indica
(Gupta
et
al.,
2004;
Biswas
et
al.,
2002;
Grover
et
al.,
2002),
Allium
sativum
(Eidi
et
al.,
2006;
Grover
et
al.,
2002),
Abrus
precatorius
(Attal
et
al.,
2010),
Solanum
incanum
(Musabayane
et
al.,
2006),
Oci-
mum
basilicum
(Vats
et
al.,
2002),
Withania
somnifera
(Udayakumar
et
al.,
2009;
Adallu
and
Radhika,
2000),
Cassia
abbreviata
(Shai
et
al.,
2010)
and
Olea
europaea
(Eidi
et
al.,
2009)
have
scientifically
demonstrated
hypoglycaemic
activity
(Table
3).
Active
principles
have
also
been
obtained
from
some
of
the
plants
cited
in
this
study.
oleuropein
and
hydroxytyrosol
Polyphenols
from
Olea
europaea
(Poudyal
et
al.,
2010),
S-allylcysteine
sulfoxide,
S-methylcysteine
sulfoxide,
and
diallyl
trisulfide
from
Allium
sativum
(Kook
et
al.,
2009)
and
foetidin
from
Momordica
foetida
(Marquis
et
al.,
1977)
are
some
of
the
phytochemical
that
have
been
obtained
and
have
demonstrated
hypoglycaemic
activity
in
diabetic
models.
Members
of
the
genera
such
as
Cactus,
Eucalyptus,
Momordica
and
Aloe,
that
were
reported
but
were
not
fully
identified
due
to
absence
of
reproductive
features
at
the
time
of
the
survey,
have
also
been
reported
to
have
hypoglycaemic
activity
(Table
3).
The
Aloe
species
with
proven
hypoglcaemic
activity
are
Aloe
vera
(Jain
et
al.,
2010;
Kim
et
al.,
2009;
Rajasekaran
et
al.,
2004;
Grover
et
al.,
2002),
Aloe
arborescens
(Beppu
et
al.,
2006)
and
Aloe
barbadensis
(Grover
et
al.,
2002;
Ajabnoor,
1990).
Antidiabetic
effect
of
the
leaf
extracts
of
Eucalyptus
globules,
Prickly
Pear
Cactus
(Opuntia
strep-
tacantha
and
Opuntia
fuliginosa)
and
the
stem
and
flowers
extracts
of
Momordica
balsamina
L.
have
also
been
experimentally
demon-
strated
(Mahmoudzadeh-Sagheb
et
al.,
2010;
Ahlem
et
al.,
2009;
Cefalu
et
al.,
2008;
van
de
Venter
et
al.,
2008;
Grover
et
al.,
2002;
Gray
and
Flatt,
1998;
Trejo-González
et
al.,
1996;
Swanston-Flatt
et
al.,
1990).
Some
related
plant
species
such
as
Ajuga
iva
which
is
related
to
Ajuga
remota
and
Strychnos
pseudoquina
a
related
species
to
Strychnos
henningsii
have
demonstrated
hypoglycaemic
effects
(Honório-Franc¸
a
et
al.,
2008;
Jaouad
El
and
Badiâa,
2002).
Increasing
evidence
in
both
experimental
and
clinical
stud-
ies
suggests
that
oxidative
stress
plays
a
major
role
in
diabetes
mellitus
development
and
pathogenesis
of
diabetic
complications.

L.K.
Keter,
P.C.
Mutiso
/
Journal
of
Ethnopharmacology
139 (2012) 74–
80 79
Increased
free
radicals
formation
or
impaired
antioxidant
defenses
occur
in
diabetic
state
(Maritim
et
al.,
2003)
and
antioxidant
ther-
apy
has
been
strongly
correlated
with
decreased
risks
for
diabetic
complications.
Both
antioxidant
nutrients
and
antioxidant
phy-
tochemicals
has
been
reported
to
alleviate
diabetes
and
diabetic
complications
(Lean
et
al.,
1999).
The
antioxidant
properties
of
some
plants
identified
in
this
study:
Cassia
abbreviata,
Azadirachta
indica
and
Strychnos
henningsii
have
been
experimentally
demon-
strated
(Oyedemi
et
al.,
2010;
Shai
et
al.,
2010;
Gupta
et
al.,
2004)
and
this
further
supports
the
use
of
these
plants
in
the
management
of
diabetes
mellitus.
Despite
the
penetration
of
conventional
medicines,
traditional
medicine
continues
to
be
a
feasible
health
care
alternative
for
the
majority
of
the
Kenyan
population.
Thus,
it
is
important
to
evaluate
the
existing
traditional
knowledge
of
the
THPs
in
the
management
of
various
diseases.
We
reported
for
the
first
time
the
medicinal
plants
used
to
treat
diabetes
in
Kenya
and
the
THPs’
existing
knowl-
edge
in
the
management
of
diabetes
mellitus.
The
widespread
comparison
between
published
information
and
claims
by
the
interviewees
justifies
pharmacological
and
toxicological
investi-
gations
to
validate
the
antidiabetic
properties
of
these
identified
plants.
Acknowledgments
This
research
was
funded
by
the
International
Foundation
for
Science
(IFS
Grants
No.
AF/18957).
We
are
grateful
to
the
THPs
who
participated
in
this
study.
We
thank
the
Director
of
KEMRI
for
allowing
publication
of
this
study.
We
also
acknowledge
Joyce
Munini
Muema,
a
social
scientist,
and
the
Office
of
the
President
Officers
(Chiefs)
of
Matungulu,
Mwala
and
Muumandu
Locations
for
helping
in
identifying
the
TMPs
to
interview.
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A.E.A.,
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Ethnobotanical
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in
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