Preclinical Evaluation of Antidiabetic Effect of Pedilanthus tithymaloides Extracts in Streptozotocin (STZ) Induced Diabetic Rats

 

S. Adhikary1*, C.C. Kandar1, P.K. Haldar2, A. Basu1 and S. Choudhury1

1Department of Pharmaceutical Chemistry; Institute of Pharmacy, Jalpaiguri; West Bengal; India – 735 101 2Division of Pharmacology, Department of Pharmaceutical Technology, Jadavpur University, Kolkata – 700 032

*Corresponding Author E-mail: sadhikari101@rediffmail.com

 

ABSTRACT:

Dried and powdered leaves of the plant Pedilanthus tithymaloides was extracted successively with chloroform and methanol using shoxlet extractor and the extracts were dried under reduced pressure at a temperature not exceeding 40°C. These extracts were subjected to different phytochemical tests and in the evaluation of antidiabetic potential on streptozotocin induced diabetic rats. Both the extract showed significant antidiabetic activity.

 

KEYWORDS: Antidiabetic activity, streptozotocin induced diabetes, Pedilanthus tithymaloides

 


INTRODUCTION:

There is growing awareness of the role and practice of integrated medicine in the field of metabolic disorders. This is based in part on a flood of scientific data reported about medicinal plants including those with antidiabetic potential1 and partly on the support provided for its practice by Governmental agencies as well as the WHO (World Health Organisation)2. Diabetes mellitus becomes a real problem of public health in developing country where its prevalence is increasing steadily and adequate treatment is often expensive and unavailable3. Alternative strategies to the current modern pharmacotherapy of diabetes mellitus are urgently needed4, because of the inability of existing modern therapies to control all the pathological aspects of the disorders, as well as the enormous cost and poor availability of the modern therapies for many rural populations in developing countries. Plants used in traditional medicine to treat diabetes mellitus represent a valuable alternative for the control of this disease. The plant Pedilanthus tithymaloides (L.) Poit. belonging to the family Euphorbiaceae  is commonly known as Rangchita and Plant of Hawaii in Bengali and English respectively.

 

The plant is a low tropical succulent shrub with milky juice, stems green, widespread, ranging from southern Florida and Maxico to northern South America, the Caribbean to India. It is reported wide range of healing properties, namely emetic, anti-inflammatory, antidiabetic, antibacterial, antiseptic, antihemorrhagic, antiviral, antitumoral, and abortive5-6.

 

In the present study, the hypoglycemic effect of chloroform and methanolic extracts of Pedilanthus tithymaloides in Streptozotocin induced diabetic rats was evaluated.

 

MATERIALS AND METHODS:

Plant Material:

The leaves of the plant were collected from the district of Jalpaiguri, India. Botanical Survey of India, Howrah, authenticated the herbarium of the plant.

 

Extraction Procedure:

The dried leaves of Pedilanthus tithymaloides were successively extracted with chloroform and methanol by continuous hot extraction process using Soxhlet apparatus. The solvent was completely removed under reduced pressure at a temperature not exceeding 40°C and stored in vacuum desiccator. The average percentage yield of chloroform (CEPT) and methanol (MEPT) extracts were found to be 2.12% and 3.35% w/w respectively.

 

Animals:

Male albino Wister rats weighing 180 – 200 g collected from North Bengal Medical College, Siliguri, India, were placed in wire netted cages in a controlled room temperature 22° ± 1°C, relative humidity 60 - 70% and with 12 h light and dark cycle. The animals were maintained with pellet diet and water ad libitum. The animals were deprived of food for 12 hours before testing for blood glucose level or injection of STZ to induce diabetes but allowed free access to drinking water throughout. Diet pellet was obtained from Hindustan Lever Ltd. All studies were carried out using six rats in each group.

 

 


Table- I: Effect of CEPT, MEPT and Standard drug on body weight (gm) of STZ induced diabetic rats.

Group/ Treatment

Days after STZ injection

0 days

20 days

Normal Control

138.0±1.94

142.2±2.52

Diabetic Control

125.5±0.22

125.6±0.33

STZ + Glipizide (5mg/kg)

147.2±1.13

146.2±2.32

STZ + CEPT (250 mg/kg)

145.5±0.99

146.0±1.77

STZ + CEPT (500 mg/kg)

128.2±1.16

129.3±1.47

STZ + MEPT (250 mg/kg)

130.8±1.99

128.3±1.25

STZ + MEPT (500 mg/kg)

135.5±2.69

134.5±2.76

Values are expressed as mean ± SEM (N=6)

 

Table-II: The effect of CEPT, MEPT and Standard drug on fasting blood glucose level of STZ induced diabetic rats

Group/ Treatment

Days after STZ injection

5 days

10 days

15 days

20 days

Normal Control

116.3±0.76

119.5±2.07

118.3±1.38

120.3±1.14

Diabetic Control

356.2±3.53

362.6±2.15

365.8±2.24

370.5±2.81

STZ+ Glipizide (5mg/kg)

338.6±8.03

312.5±4.08

235.2±4.26

170.5±3.75

STZ+CEPT (250 mg/kg)

364.2±6.28

340.6±4.47

215.5±3.83

290.6±4.32*

STZ+CEPT (500 mg/kg)

340.3±6.04

305.3±5.44

282.3±6.57

235.2±5.28*

STZ+MEPT (250 mg/kg)

343.6±7.09

314.6±8.36

270.2±6.70

225.2±5.78*

STZ+MEPT (500 mg/kg)

362.3±7.88

308.1±5.37

240.6±5.81

195.0±4.72*

Values are expressed as mean ± SEM (N=6). * p< 0.001

 


Experiments Conducted:

The preliminary phytochemical analyses of the extracts were carried out as per the methods reported in standard literature7.

 

Antidiabetic activity study:

For induction of diabetes the rats were kept on fasting prior to STZ injection. On the day of administration, STZ was freshly dissolved in citrate buffer (pH 4.5) and intraperitoneal injection was given at the dosage of 60 mg/ kg body weight. Fasting Blood sugar (FBS) level was measured using Accu-Chek Active Blood Glucose Monitor of Roche Diagnostic India Pvt. Ltd. bearing the serial No. GN02303293. Rats were divided into 7 (seven) groups each containing 6 (six) rats8, namely,

Group-I – Normal Control rats

Group-II – Diabetic Control rats

Group-III – Diabetic rats received standard drug, Glipizide (5 mg/ kg B.W)

Group-IV - Diabetic rats received CEPT (250 mg /kg B.W)

Group-V - Diabetic rats received CEPT (500 mg /kg B.W)

Group-VI - Diabetic rats received MEPT (250 mg /kg B.W)

Group-VII - Diabetic rats received MEPT (500 mg /kg B.W)

 

Fasting Blood sugar level was measured at 5 days, 10 days, 15 days and 20 days after STZ injection.

Statistical analysis: ANOVA was used to compare the difference between the observations of different groups. The level of significance was set at p< 0.05.

 

RESULTS AND DISCUSSION:

The body weight of rats treated with standard drug and extracts in STZ induced diabetes is summarized in table-I. There is no significant change in body weights of treated rats.

 

The effect of CEPT, MEPT and Standard drug on fasting blood glucose level of STZ induced diabetic rats was summarized in Table II. The FBS was increased upto 3.5 times of normal control value on the day zero of treatment in group-II, III, IV, V, VI and VIII and was significantly reduced in all treatment groups after 20 days of treatment. In the normal control and treatment groups, 20 days after treatment, the blood glucose level were reduced to nearly fasting level. From the table II, it is clear that the hypoglycemic effect methanolic extract is better than that of chloroform extract.

 

REFERENCES:

1.       Grover JK, Yadav S and Vats V (202). Medicinal plant of India with antidiabetic potential. Journal of Ethnopharmacology, 81: 81-100.

2.       World Health Organization (1980). WHO Expert Committee on Diabetes Mellitus Second Report. Technical Report Series. 646:61.

3.       DjroloF, Hounge H, Avode G, Addra B, Kodjoh N, Avinadje M and Monterio B (1998). Le diabete lie a la mal nutrition (Diabetic tropical). Medicine Afrique Noire 45 (8/9): 538-542.

4.       WHO (2002). WHO launches the first global strategy on traditional medicine: Press release WHO/38.

5.       Caceres, A., Menendez, H., Mendez, E., Cohobon, E., Samayoa, B.E., Jauregui, E., Peralta, E. and Carrillo, G. (1995) Antigonorrhoeal activity of plants used in Guatemala for the treatment of sexually transmitted diseases. Journal of Ethnopharmacology., 48, 85–88.

6.       Renne, E.P. (1996) The pregnancy that doesn’t stay: the practice and perception of abortion by Ekiti Yoruba women. Social Science and Medicine. 42, 483– 494.

7.       Kokate CK, Practical Pharmacognosy, Pub. Vallabh Prakashan, India, 2000

8.       Sridhar S.B, Sheetal U.D, Pai M.R.S.M and Shastri M.S. (2005). Preclinical evaluation of anti-diabetic effect of Eugenia jambolana seed powder in Streptozotocin-diabetic rats. Brazilian Journal of Medical and Biological Research, 38: 463 – 468.

 

 

 

Received on 09.04.2010       Modified on 12.05.2010

Accepted on 29.05.2010      © RJPT All right reserved

Research J. Pharm. and Tech.3 (4): Oct.-Dec.2010; Page 1132-1133