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Ethnobotanical
Leaflets 14: 648-53. 2010. Foliar
Epidermal Morphology and Anti-Diabetic Property of Andrographis paniculata (Burm. f.) Wall ex. Nees *T. R. Fasolaa
, A. E. Ayodelea, A. A. Odetolab, and N. E.
Umotoka a Department of
Botany and Microbiology, Faculty of Science, University of Ibadan, Ibadan,
Nigeria b Department of
Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University
of Ibadan, Ibadan, Ibadan *E-mail: fasolatr@yahoo.com Issued
May 1, 2010 Abstract The leaf epidermal
features and anti diabetic property of Androgragphis
paniculata were investigated. The epidermal cells are polygonal to
irregular with curved to undulate anticlinal walls on both surfaces of the
leaf. The leaf is hypostomatic with stomata restricted to the abaxial
surface. Stomata type is axillocytic. The epidermal cells contain deposits of
crystal oxalates while cystoliths are found in a few cells. The leaf extract
was evaluated for hypoglycemic effects. There was significant hypoglycemic
effect in alloxan induced diabetic rats following administration of the leaf
aqueous extract. The result shows that the level of fasting blood sugar was
dependent on the previous level of basal blood sugar in the four groups of
rats used for this study. Treatment of the rats with A. paniculata showed a dose dependent relationship with the time
it took for the blood of the rats to return to the basal blood sugar levels.
The study supports the use of the plant in the management and treatment of diabetes. Key
words: Andrographis
paniculata; diabetes mellitus, antidiabetic
properties, foliar epidermis. Introduction Andrographis
paniculata (Burm.f.)Wall ex Nees is a small
herbaceous plant of about 30-60m high. It is a member of the family
Acanthaceae. A. paniculata is a
native of India or Sri Lanka but now introduced to Nigeria and widely
cultivated for its medicinal properties in south western Nigeria. The extract
from the leaves and the roots is traditionally and widely used to treat
various diseases such as cancer [Kumar et
al., 2004; Pajagpal et al.,
2003], upper respiratory tract infections [Poolsup et al., 2004; Coon and Ernst, 2004], filiariasis [Dutta and
Sukul, 1982] and snakebites [Martz, 1992]. A. paniculata possesses hypoglycemic properties. An aqueous
extract of A. paniculata has been
shown to have hepatoprotective effects against carbon tetrachloride induced
liver damage [Rana and Avadhoot, 1991]. The hypotensive activity of an
aqueous extract of the plant has been demonstrated in rats [Zhang and Tan,
1996]. The plant is known to
be beneficial following extracorporeal shock lithotripsy [Muangman et al., 1995]. The leaf extract of A. paniculata possesses antiplatelet
aggregation [Amroyan et al., 1999],
antifertility effect [Zoha et al.,
1989] and uterus relaxation [Burgos et
al., 2001].The main bioactive component of the plant is known to be a
labdane diterpenoid called Andrographolide (Coon and Ernst, 2004). This study was
undertaken to obtain information on the epidermal features of the leaf and to
assess the hypoglycemic effect of A.
paniculata leaf extract based on ancient reports of this property. Materials
and Methods Plant
material Samples of A. paniculata were collected from
Kabba, Kabba Local Government Area in Kogi State of Nigeria and the Botanical
Nursery of the Department of Botany and Microbiology, University of Ibadan,
Ibadan, Nigeria. The plant materials were authenticated at the Herbarium of
the Department of Botany and Microbiology, University of Ibadan, Nigeria
(UIH) where voucher specimens were also deposited. Epidermal
morphology Fresh leaves were
obtained from the nursery of the Department of Botany and Microbiology,
University of Ibadan, Ibadan, Nigeria while the dry leaves from the specimens
from Kabba, were boiled in water for about five minutes to revive the cells.
Methods of epidermal preparation follow Ayodele and Olowokudejo (1997; 2006).
Descriptive terminology is according to Dilcher (1974). Preparation of the extract Leaves of Andrographis paniculata were collected
early in the morning at about 9am. These were air dried at room temperature
and later ground into powder form with the aid of an industrial blender. An
aqueous extract was obtained by soaking 1g of the powdered leaves in 100ml of
distilled water to produce 10mg/ml of aqueous extract. Experimental
animals Thirty healthy Wistar
rats (175-250g) maintained under normal or standard conditions were obtained
from the animal house, Department of Veterinary Physiology, Faculty of
Veterinary Medicine, University of Ibadan, Ibadan. Animal feeds were obtained
from Caps Feed Mill Limited, Ibadan, Nigeria. Induction
of diabetes mellitus in the rats with intramuscular alloxan. Ten percent alloxan
dissolved in physiological saline was used to induce diabetes mellitus in the
rats. Ten grammes of fresh sample of alloxan was weighed on a Mettler’s
balance and dissolved in 100ml of 0.15M physiological saline solutions to
produce 10% alloxan. The dose administered was a standard dose of 100mg/kg
weight of the rats. The exact volume of the drug administered was obtained
using the general formula: Volume to be administered = Weight
of animal (g) x Dose of drug (mg/kg)
1000 x Concentration
of drug (mg/ml) The rats were divided into six
treatment groups of five rats per group. The first four groups of rats were
given intramuscular injection of 100mg/kg alloxan and Fasting Blood Sugar
(FBS) was checked after 48 hours. The rats with fasting blood sugar between
100 – 500mg/dl were considered to be diabetic. Effect
of plant extract on the diabetic rats The diabetic rats in
each of the four groups were subsequently treated with different doses of
(50mg/kg, 100mg/kg, 200mg/kg and 400mg/kg) of the plant extract twice daily
for two weeks. This was administered orally with the use of oral canula. The
fasting blood sugar was checked every two days by cutting a bit of the rats’
tails for a drop of blood and dropping the blood on a specified space on the
glucometer and the reading was recorded. The fifth group (nondiabetic, not
injected with alloxan had 400mg/kg of A.
paniculata administered into them and the fasting blood sugar was
recorded every two days for two weeks. The sixth group (control group) was
fed with only feeds with clean water daily and their fasting blood sugar
observed every two days and compared with the fasting blood sugar of the
fifth group. Statistical
analysis The results are
expressed as MEAN±SEM. The student’s t test was used to determine the
significance of difference between control and treated groups. The level of
significance was taken as p < 0.05. Results
and Discussion The results of this
study are summarized in Figures 1- 3 and Tables 1-3. Figure 1 shows the habit
A. paniculata as grown in the
nursery of the Department of Botany and Microbiology, University of Ibadan,
Ibadan, Nigeria, while figures 2 and 3 are photomicrographs of the adaxial
and abaxial epidermis of the leaf of the plant. The epidermal cells are
polygonal to irregular with curved to undulate anticlinal walls on both
surfaces of the leaf (Figs. 2 and 3). The leaf is hypostomatic with stomata
restricted to the abaxial surface. Stomata type is axillocytic (Fig.3) with
one cell nearly enclosing both guard cells except for one free pole which is
covered by two cells with a common anticilnal wall extending from the pole
parallel to the long axis of the guard cells. The epidermal cells contain
deposits of crystal oxalates while cystoliths are found in a few cells (Figs.
2 and 3). Table 1 shows the mean basal blood
sugar levels of the four groups of rats and the mean fasting blood sugar
levels after two days as a result of the induction of diabetes mellitus by
intramuscular administration of alloxan. The result shows that the level of
fasting blood sugar was dependent on the previous level of basal blood sugar
in the four groups of rats. Treatment of the rats with A. paniculata showed a dose dependent relationship with the time
it took for the blood of the rats to return to the basal blood sugar levels (Table
2). The maximum time was observed in Group 1 rats (i.e. those treated with
50mg/kg) which was more than 14 days. This was followed by Groups 2 and 3
(100 and 200mg/kg respectively). The shortest time of treatment was observed
in the Group 4, those treated with the highest dose (400mg/kg). The administration of
A. paniculata in normal rats showed
that at the end of the two weeks, the mean fasting blood sugar had reduced
from 51.4mg/dl to 42.0mg/dl (Table 3). In summary, the results of this study
support the hypoglycemic properties of Andrographis paniculata as well as confirm the blood sugar reducing. ReferencesAmroyan, E., Gabrielian, E., Panossian, A., Wikman, G. and Wagner, H. (1999). Inhibitory effect of andrographolide from Andrographis paniculata on PAF- induced platelet aggregation. Phytomedicine.: 6(1):27-31 Ayodele,
A.E. and Olowokudejo, J.D. (1997). Systematic importance of leaf and epidermal
characters in West African species of family Myrtaceae. Boletim da Sociedade
Broteriana 68: 35-72. Ayodele,
A. E. and Olowokudejo, J.D.
(2006). The family Polygonaceae in West Africa : Taxonomic significance of
leaf epidermal characters. South
African Journal of Botany 72 : 442 - 459 Burgos, R.A. Aguila, M. J. Santiesteban, E.T.,
Sanchez, N.S. and Hancke, J. L.
(2001). Andrographis paniculata (Ness) induces relaxation of
uterus by blocking voltage operated calcium channels and inhibits Ca(+2)
influx. Phytother-Res.:
15(3): 235-9 Coon,
J. T. and Ernst, E. (2004). Andrographis paniculata in the treatment of upper
respiratory tract infections: a systematic review of safety and efficacy. Planta
Med. 70(4):293-8. Dilcher,
D. L. (1974). Approaches to the identification of Angiosperm leaf remains. The Botanical Review 40:1-157 Dutta,
A. and Sukul, N.C. (1982). Filaricidal properties of a wild herb, Andrographis paniculata. J. Helminthol
56: 81 - 84. Kumar, R.A, Sridevi, K., Kumar N.V., Nanduri, S.
and Rajagopal, S. (2004). Anticancer
and immunostimulatory compounds from Andrographis
paniculata. J. Ethnopharmacol 92 (2-3):291-5. Martz,
W. (1992). Plants with a reputation
against snakebite. Toxicon. 30(10):1131-42. Muangman
V, Viseshsindh V, Ratana-Olarn K and Buadilok (1995). The usage of Andrographis
paniculata following extracorporeal shock wave lithotripsy ESWL). J Med
Assoc Thai: 78(6): 310-313 Pajagopal,
S., Kumar, R.A., Deevi, D.S., Satyanarayana, C. and Rajagopalan, R. (2003). Andrographolide,
a potential cancer therapeutic agent isolated from Andrographis paniculata.
J Exp Ther Oncol 3: 147-158. Poolsup, C., Suthisisang, C., Prathanturarug, S.,
Asawamekun, A. and Chanchareon, U. (2004).
Andrographis paniculata in the symptomatic treatment of uncomplicated upper
respiratory tract infection: systematic review of randomized controlled trials.
J Clin Pharm Ther 29:37-45 Rana,
A.C. and Avadhoot, Y. (1991), Hepatoprotective effects of Andrographis
paniculata against carbon tetra-chloride induced liver damage. Arch Pharm Res:14 (1):93-95 Zhang,
C.Y. and Tan, B.K. (1996), Hypotensive activity of aqueous extract of Andrographis paniculata in rats. Clin
Exp Pharmacol Physiol. 23: 675-678 Zoha,
M.S., Hussain, A.H. and Choudhury, S.A. (1989). Antifertility effect of Andrographis paniculata in mice.
Bangladesh
Med Res Counc Bull: 15(1):34-7.
Table 1. The mean values of Fasting Blood Sugar
(mg/dl) of the four groups of rats after injection of alloxan.
Table 2. The
effects of administration of different doses of different doses of A. paniculata in various groups of
diabetic rats on mean values of Fasting Blood Sugar (mg/dl) taken on
alternate days. Alternate days that
Fasting Blood Sugar levels were taken
Table 3. The mean values of Fasting Blood Sugar
(mg/dl) of Group 5 rats and Group 6 (Control group) rats taken on alternate
days. Alternate days
that Fasting Blood Sugar levels were taken
Fig.1:
Photograph showing the habit of Andrographis
paniculata.
Fig.
2: Adaxial epidermal surface of A.
paniculata.
Fig.
3: Abaxial epidermal surface of A.
paniculata. |
