Antidiabetic Activity of Andrographis paniculata

Abstract

The hot water and ethanol extracts of Andrographis paniculata (local name Kalomegh) collected from Chittagong exhibited a significant hypoglycemic (blood glucose lowering) activity in both glucose-loaded and alloxan-induced diabetic rats. Oral administration of glucose (1.5 g/kg body weight) increased the blood sugar level while the intraperitonial (ip) administration of alloxan (40 mg/kg body weight) enhanced the blood sugar level much higher than that of the glucose-loaded rats. The hot water (0.8 g/kg b.w.) and ethanol extracts (2 g/kg b.w.) of A. paniculata reduced the elevated glucose level by 41.51 and 41.82%, respectively in glucose-loaded rats as compared to the respective diabetic control rats. On the other hand, administration of hot water and ethanol extracts of A. paniculata decreased the blood sugar level by 46.21 and 45.13%, respectively in alloxan-induced diabetic rats, when compared with that of diabetic control rats.

Full text

Antidiabetic Activity of Andrographis paniculata
Md. Alamgir Hossain1,∗, B.K. Roy2, Kabir Ahmed2,
A.M. Sarwaruddin Chowdhury1 and M.A. Rashid3
2BCSIR Laboratories Chittagong, P.O. Chittagong Cantonment, Chittagong-4220, Bangladesh
1Department of Applied Chemistry and Chemical Technology, University of Dhaka, Dhaka-1000, Bangladesh
3Center for Biomedical Research, Faculty of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh
ABSTRACT: The hot water and ethanol extracts of Andrographis paniculata (local name Kalomegh) collected from
Chittagong exhibited a significant hypoglycemic (blood glucose lowering) activity in both glucose-loaded and
alloxan-induced diabetic rats. Oral administration of glucose (1.5 g/kg body weight) increased the blood sugar level
while the intraperitonial (ip) administration of alloxan (40 mg/kg body weight) enhanced the blood sugar level much
higher than that of the glucose-loaded rats. The hot water (0.8 g/kg b.w.) and ethanol extracts (2 g/kg b.w.) of A.
paniculata reduced the elevated glucose level by 41.51 and 41.82%, respectively in glucose-loaded rats as compared
to the respective diabetic control rats. On the other hand, administration of hot water and ethanol extracts of A.
paniculata decreased the blood sugar level by 46.21 and 45.13%, respectively in alloxan-induced diabetic rats, when
compared with that of diabetic control rats.
Keywords. Andrographis paniculata, Glucose-loaded, Alloxan-induced, Rats, Antidiabetic.
INTRODUCTION
Diabetes is a disorder of metabolism due to
absolute deficiency or diminished effectiveness of
insulin. Due to lack of insulin, hyperglycemia and
glycosuria almost invariably occur.1 It is a fatal
health problem in the present world. Diabetes is the
fourth-leading cause of death.2 The diabetic
population is rapidly increasing globally, particularly
in the developing countries. South Asian region
including Bangladesh is the most vulnerable focus.
The current worldwide diabetic population is about
150 million, and this will be doubled by 2025.3 The
estimated prevalence of diabetes in Bangladesh is
Correspondence to:
Mohammad A. Rashid; Tel.: 880-2-8612069, 9661900-73,
extn.- 4363, 8137; Fax: 880-2-8612069,
E-mail address: rashidma@aitlbd.net
*On Leave from Directorate of Secondary and Higher Education,
Bangladesh
Dhaka Univ. J. Pharm. Sci. 6(1): 15-20, 2007 (June)
around 4%, which is similar to the average
prevalence in many other countries. But the
prevalence of impaired glucose tolerance (IGT) here
varies between 7.5-10% depending on urban and
rural backgrounds.4 A significant proportion of these
patients obviously fail to get proper treatment and
medication. Indigenous drugs, since long, have been
used for the treatment of diabetes.5 Hundreds of
plants are known to be useful in treating diabetes in
different corners of the world. Bangladesh is
abundant in antihyperglycemic plants. These species
may represent a source of new hypoglycemic
compounds for developing better remedies to treat
diabetic patients without serious side effects.
Andrographis paniculata (Burm. f.) Wall
(=Justicia paniculata Burm.f.), locally known as
Kalomegh (English name Creat), belonging to the
Acanthaceae family, is an annual herb that grows
wild in wastelands throughout Bangladesh
(particularly in Chittagong hill tracts) and

16 Hossain et al.
occasionally planted in gardens. Previous chemical
investigations of A. paniculata revealed the
occurrence of a resinous bitter substance, kalmeghin,
the diterpenes, andrographolide, andrographiside and
neoandrographolide. Extracts are known to contain
14-deoxy-11-oxoandrographolide, 14-deoxyandro-
grapholide, 14-deoxy-11,12-idehydroandographolide
and14-deoxy-11,14-didehydro-andrographolide, epi-
genin ethers and various flavonoids, phenols and
stigmasterol. On the other hand leaves are reported to
contain β-sitosterol glucoside, andrographolide and
panicolide, polyphenols, caffeic and chlorogenic
acids and a mixture of dicaffeoylquinic acid.6
The plant possesses hypoglycemic, cholagogue
properties and also used in spleen & liver complaints,
diarrhea, dysentery, dyspepsia, helmenthiasis, colic
and conspitation.7,8 Andrographolide and extract of
the plant have been shown to be a strong
hepatoprotective drug. Husen et al.9 and Zhang et
al.10 have reported the antihyperglycemic property of
A. paniculata in streptozotocin-induced
hyperglycemic rats but enough evidence was not
available to confirm the hypoglycemic activity of the
various extracts on different hyperglycemic
conditions. In this paper, we report the hypoglycemic
activity of hot water and ethanol extracts of the aerial
parts of A. paniculata growing in Bangladesh in
glucose-loaded hyperglycemic and alloxan-induced
diabetic rats.
MATERIALS AND METHODS
Collection of plant material. The aerial parts of
A. paniculata were collected from plantation area of
the BCSIR Laboratories, Chittagong and adjacent
hilly regions and were identified at the Plant
Taxonomy Division. The plants were cut into small
pieces and were dried at room temperature for about
20 days, followed by drying in an oven and were then
ground to a coarse powder.
Preparation of plant pxtracts
Hot Water Extract. For preparing water extract
the powder of A. paniculata (about 2 g, according to
need) was mixed with distilled water (1 : 12), boiled
for 5-7 minutes, cooled at room temperature and
filtered through a filter paper. The liquid (aqueous
extract) was then administered to rats through feeding
needle.
Calculation of solid content in water extract.
1g of the prepared powder was taken in 250 ml
beaker to which 12 ml of distilled water was added
and the mixture was heated on a burner for about 5-7
minutes, cooled and filtered through a filter paper.
The liquid extract was dried in oven to drive off
water. The solid portion thus obtained was measured
with an electronic balance.
Ethanol extract. The powder of A. paniculata
was soaked in ethanol in a closed glass bottle for 7
days. Then the extractive was filtered using a filter
paper. The extract, thus obtained was concentrated
under reduced pressure at about 45-50 ºC with a
rotary vacuum evaporator.
Animal and diet. Adult male and female albino
rats obtained from the Animal Breeding Center,
BCSIR Laboratory, Chittagong, Bangladesh
weighing 200-230 g were used for the study. The rats
were acclimatized to standard laboratory conditions
(relative humidity 55 ± 5%, temperature 24 ± 1ºC and
a 12 h diurnal photoperiod) in galvanized cages (3-6
rats/cage) with replaceable wire-meshed net lid for 7
days before the commencement of the experiment.
During the study, all animals were maintained on
normal laboratory chow, ad libitum water.
Induction of diabetes in rats. In glucose-loaded
study, rats were fasted overnight (18 h) before oral
feeding of glucose. Glucose at a concentration of 1.5
g/kg b.w. was dissolved in distilled water
immediately before administration through feeding
needle. Alloxan (40 mg/kg b.w.) was injected
intraperitonially and after that, the rats were fasted
for 18 hours.
Estimation of blood sugar level (BSL). The
level of glucose in blood samples from each of the
experimental and control rat was determined by using
standard glucose kit essentially following the glucose
oxidase-peroxidase (GOD-POD) method.11 The
blood was centrifuged to get a clear supernatant

Antidiabetic Activity of Andrographis paniculata 17
100x
groups control fromMean
groups) treatedfromMean groups control from(Mean
(serum). 2 µl of serum was taken in 2 ml test solution
in a separate test tube. The intensity of the color of
the solution was measured spectrophotometrically at
546 nm for quantification of the glucose initially
present in the blood specimen.
EXPERIMENTAL PROTOCOL
For glucose-loaded experiments. 28 rats were
randomly divided in equal number into four groups
(marked I, II, III, IV). One group (Gr-I, 7 rats)
received only distilled water and termed as vehicle
control group. The three experimental groups (Gr-II,
III, IV) were orally administered with 1.5 g/kg b.w
glucose solution. Gr-II rats were considered as
diabetic control (only glucose), while Gr-III rats
received 4 mg/kg b.w. Daonil [Glibenclamide BP
tablet, 5mg, a standard market drug for non-insulin
dependent diabetes mellitus (NIDDM, type-2)
treatment] and served as the positive control (drug
treated). Gr-IV was given with either the hot water or
ethanol extract at different experimental regimen and
was considered as sample treated.
−
Time schedule for glucose-loaded experiment.
All the animals were primarily fasted for 18 hours
(given only distilled water) and then glucose solution
was given through feeding needle. After 2 hours,
distilled water, drug solution and A. paniculata
extracts, prepared with water were given orally
according to rats of respective group. Two hours
later, all the animals were anesthetized with diethyl
ether and blood sample were collected from cardiac
vessel by syringe for every observation in each study.
For alloxan induced experiments. Rats were
grouped in an identical manner to glucose-loaded
classification. Gr-I rats received only distilled water.
Rats of groups-II, III and IV were intraperitonially
injected alloxan tetrahydrate (40 mg/kg b.w.). Gr-II
rats were considered as diabetic control (only
alloxan), Gr-III rats also received 4 mg/kg b.w.
Diactin (Glipizide BP tablet 5 mg, a standard drug
indicated as an adjunct to diet the control of
hypoglycemia in NIDDM) and termed as positive
control. Gr-IV rats were treated with hot water or
ethanol extract at different experimental observation
and were designated as the sample treated group.
Time schedule for alloxan induced
experiment. All the animals were injected with
alloxan and were fasted for 18 hours. Then standard
drug and sample extract were given orally to the rats
group wise in every experiment. Two hours later of
treatment, blood samples were collected as described
before.
Statistical analysis (Calculation). Student’s ‘t’
test was formulated for analysis of data from each
experimental group. Percentage change in glucose
level (increased or decreased) was determined by
using the formula:
RESULTS AND DISCUSSION
Effect of hot water extract of A. paniculata on
blood sugar level (BSL) of glucose-loaded rats.
The effect of hot water extract of A. paniculata on
BSL of glucose-loaded rats is presented in Table 1.
Administration of glucose increased the BSL of rats
by 89.47% as compared to vehicle-control rats while
the hot water extract of A. paniculata significantly (p
< 0.001) decreased the glucose elevated BSL by
41.51% as compared to diabetic control (glucose-
loaded) rats. In the case of standard drug, Daonil
treatment, the percent of BSL decrease was 44.70.
Effect of ethanol extract of A. paniculata on
BSL of glucose-loaded rats. The effect of ethanol
extract of A. paniculata on BSL of glucose-loaded
rats is shown in Table 2. Administration of glucose
increased the rats BSL by 87.07% when compared to
vehicle-control rat. On the other hand, rats treated
with ethanol extract of A. paniculata significantly (p
< 0.001) lowered 41.82% the enhanced BSL as
compared to diabetic control rats. In the case of drug
(daonil) treatment group, the glucose level was
lowered by 45.63%.
Effect of hot water extract of A. paniculata on
BSL of alloxan-induced rats. Table 3 depicts the

18 Hossain et al.
effect of hot water extract of A. paniculata on BSL of
alloxan-induced diabetic rats. Administration of
alloxan increased the BSL of rat by 104.69% as
compared to the vehicle control group. On the other
hand, rats treated with the hot water extract of A.
paniculata significantly (p < 0.001) lowered the
elevated BSL by 46.21% when compared to diabetic
control group. In this situation, the standard drug
reduced the BSL by 49.66%.
Effect of ethanol extract of A. paniculata on
BSL of alloxan-induced rats. Table 4 shows the
serum blood sugar level in vehicle control, diabetic
control (alloxan), standard drug and sample treated
groups. Alloxan enhanced the BSL by 104.61% when
compared with vehicle-control rats. On the other
Table 1. Effect of hot water extract of A. paniculata on blood sugar level (BSL) of glucose-loaded rats.
Group Treatment Blood sugar levela
(Mean±S.D, mg/dl)
Percent changed
(Increased/decreased)
I Vehicle control 60.77 ± 3.28 -
II Diabetic control 115.14 ± 2.36 89.47 (↑)
III Drug treated (Daonil) 63.67 ± 3.05 44.70 (↓)
IV Sample treated 67.35 ± 2.17 41.51 (↓)
aValues are Mean ± S.D. (n=7) S.D. = Standard deviation. n = number of rat
Table 2. Effect of ethanol extract of A. paniculata on BSL of glucose-loaded rats.
Group Treatment Blood sugar levela
(Mean ± S.D, mg/dl)
Percent changed
(Increased/decreased)
I Vehicle control 61.40 ± 3.34 -
II Diabetic control 114.86 ± 1.62 87.07 (↑)
III Drug treated (Daonil) 62.45 ± 4.02 45.63 (↓)
IV Sample treated 66.83 ± 2.36 41.82 (↓)
aValues are Mean ± S.D (n=7); S.D. = Standard deviation. n = number of rat
Table 3. Effect of hot water extract of A. paniculata on BSL of alloxan-induced rats.
Group Treatment Blood sugar levela
(Mean ± S.D, mg/dl)
Percent changed
(Increased/decreased)
I Vehicle control 60.22 ± 3.19 -
II Diabetic control 123.27 ± 3.68 104.69 (↑)
III Drug treated (Diactin) 62.31 ± 5.18 49.66 (↓)
IV Sample treated 66.31 ± 4.93 46.21 (↓)
aValues are Mean ± S.D (n=7); S.D. = Standard deviation. n = number of rat
Table 4. Effect of ethanol extract of A. paniculata on BSL of alloxan-induced rats.
Group Treatment Blood sugar levela
(Mean ± S.D, mg/dl)
Percent changed
(Increased/decreased)
I Vehicle control 61.21 ± 3.25 -
II Diabetic control 125.24 ± 3.19 104.61 (↑)
III Drug treated (Diactin) 61.30 ± 3.06 51.05 (↓)
IV Sample treated 68.72 ± 5.02 45.13 (↓)
aValues are Mean ± S.D (n=7); S.D. = Standard deviation. n = number of rat

Antidiabetic Activity of Andrographis paniculata 19
Table 5. Comparison of the effect of hot water and ethanol extract of A. paniculata on blood sugar of glucose-loaded rats.
Group Treatment Hot water extract
(Mean ± S.D., mg/dl)
Ethanol extract
(Mean ± S.D., mg/dl)
I Vehicle control 60.77 ± 3.28 61.40 ± 3.34
II Diabetic control 115.14 ± 2.36 114.86 ± 1.62
IV Sample treated 67.35 ± 2.17 66.83 ± 2.36
Percent decrease 41.51 41.81
Values are Mean ± S.D (n=7); S.D. = Standard deviation.
Table 6. Comparison of the effect of hot water and ethanol extract of A. paniculata on blood sugar in alloxan-induced diabetic rats.
Group Treatment Hot water extract
(Mean ± S.D., mg/dl)
Ethanol extract
(Mean ± S.D., mg/dl)
I Vehicle control 60.22 ± 3.19 61.21 ± 3.25
II Diabetic control 123.27 ± 3.68 125.54 ± 3.19
IV Sample treated 66.31 ± 4.93 68.72 ± 5.02
Percent decrease 46.21 45.13
aValuse are Mean ± S.D (n=7); S.D. = Standard deviation. n = number of rat
hand, treatment of rats with ethanol extract of A.
paniculata significantly (p < 0.001) decreased
45.13% the alloxan elevated BSL. Here, the percent
of BSL decreasing effect of the standard drug,
Diactin was 51.05.
CONCLUSION
It is clearly evident from the study that the
aqueous and ethanolic extractives of A. paniculata
are capable to exhibit significant blood sugar
lowering effects in both glucose-loaded and alloxan
induced diabetic rat (Tables 1-4). Thus the folk use of
this plant in treating diabetes is justified. Moreover,
the lowering of blood glucose levels by the aqueous
and ethanolic extracts is also comparable. Both
extractives are capable to reduce the sugar level
almost identically as evident from Tables 5 and 6.
ACKNOWLEDGEMENTS
The authors wish to thank to Dr. Md.Yusuf,
PSO, Mr. J. U. Chowdhury, PSO, Dr. Jaripa Begum,
PSO, Dr. B. K. Saha, SSO; BCSIR Laboratories,
Chittagong for their valuable suggestions,
identification of plant and for providing instrumental
facilities for the study. The authors are thankful to
Mr. Md. Mostafa, Mr. Md. Rafique Chowdhury and
Mr. Abdul Awal Khandakar for assisting in plant
collection, preparation of extracts, maintenance of
animals and in every stage related to the experiment.
We are also cordially grateful to Dean Office, Faculty
of Pharmacy, University of Dhaka for providing with
online and other facilities in this connection.
REFERENCES
1. Hyder, S., Sayeed, A., Ahmed, A. and Ashraf, R. 1998-99.
Prescriber’s Guide 10th edition SHARUPA, Dhaka, p. 42.
2. Saha, B.K., Sarker, A.K., Ahmed, K., Roy, B.K. and
Hossain, M.E. 2006. Effect of Lagerstroemia speciosa L.
(Jarul) leaves extracts on alloxan-induced diabetic rat.
Hamdard Medicus. XLIX, No-2).
3. Siddiqui, M.N.I. and Khan, A.R. 2003. Primary prevention of
Type 2 diabetes- is it really possible? Diabetes and
Endocrine Journal 31, 33
4. Samira, H.H., Lahiry, S., Rahman, H., Biswas, K.B. and
Islam R. 2003. Prevalence of Diabetes Mellitus among a
Tribal Population (Rakhaiyans) in the South-Coastal Belt of
Bangladesh. Diabetes and Endocrine Journal 31, 9
5. Said, M. 1969. Hamdard Pharmacopoeia of Eastern
Medicine. Hamdard National Foundation, Time Press,
Karachi, p. 379.
6. Ghani, A. 2003. Medicinal Plants of Bangladesh with
Chemical Constituents and Uses, 2nd edition, Asiatic Society
of Bangladesh, p. 99.

20 Hossain et al.
7. Ghani, A. 1998. Medicinal Plants of Bangladesh, Chemical
Constituents and Uses.1st edn. Asiatic Society of Bangladesh,
p.211.
8. Yusuf, M., Chowdury J.U., Wahab, M.A. and Begum J.
1994. Medicinal Plants of Bangladesh. BCSIR Lab.,
Chittagong, pp. 21-22, 319.
9. Husen, R., Pihie, A.H. and Nallappan, M. 2004. Screening
for antihyperglycemic activity in several local herbs of
Malaysia. Journal of Ethnopharmacology 95, 205-8.
10. Zhang, X.F. and Tan, B.K. 2000. Antidiabetic property of
ethanolic extract of Andrographis paniculata in
streptozotocin-diabetic rats. Acta Pharmacology Sin. 21,
1157-64.
11. Teuscher, A. and Richterich, P. 1971. Pro fotometrické
stanoveni koncentrace glukôzy v plné krvl, séru,
plazmĕ,moĕi, mozkomisnim moku metodou Glue-DH®.
Scheiz med. Wschr 101, 345 and 390.