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Journal of Ethnopharmacology 127 (2010) 565–567

Contents lists available at ScienceDirect

Journal of Ethnopharmacology

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thnopharmacological communication

ntidiabetic activity of aqueous fruit extract of Cucumis trigonus Roxb. intreptozotocin-induced-diabetic rats

d. Salahuddin ∗, Sunil S. JalalpureLE University, Nehru Nagar, Belgaum, Karnataka, India

r t i c l e i n f o

rticle history:eceived 7 November 2008eceived in revised form 9 September 2009ccepted 15 October 2009vailable online 23 October 2009

eywords:ucumis trigonusntidiabeticerum levelipid profile

a b s t r a c t

Ethnopharmacological relevance: Cucumis trigonus Roxb. (Cucurbitaceae) fruit is used in the Indian tra-ditional medicine for the treatment of diabetes. Based on a number of reports on the blood glucoselevel reduction and the other complications of diabetes associated with some Cucurbitaceae plants, theantidiabetic effect of Cucumis trigonus fruit was investigated.Aim of the study: To investigate the antidiabetic action of the aqueous extract of Cucumis trigonus fruitsin the different models of rats.Materials and methods: The antidiabetic activity of aqueous extract of Cucumis trigonus fruit was evaluatedby using normal and streptozotocin-induced-diabetic rats. The acute effect of aqueous extract was eval-uated by administering 500 mg/kg p.o. to normoglycemic rats. In the chronic model, the aqueous extractwas administered to normal and STZ-induced-diabetic rats at dose of 500 mg/kg p.o. per day for 21 days.Blood glucose levels and body weights were monitored at specific intervals and different biochemical

libenclamideparameters were also carried out.Results: The statistical data indicated the significant increase in the body weight, liver glycogen andserum insulin level and decrease in the blood glucose, glycosylated hemoglobin levels, total cholesteroland serum triglycerides. HDL cholesterol level was significantly increased when treated with the extract.Conclusion: The aqueous fruit extract of Cucumis trigonus has had beneficial effects in reducing the elevated

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blood glucose level and li

. Introduction

Cucumis trigonus Roxb. a tendrillar herb belongs to the fam-ly Cucurbitaceae has been used as a thermogenic, anthelmintic,ebrifuge, expectorant, liver tonic, stomachic, appetizer, purga-ive and as an intellect promoting (Kirtikar and Basu, 1935).he fruit of Cucumis trigonus is reported to be useful in treat-ng conditions such as leprosy, fever, jaundice, diabetes, cough,ronchitis, anaemia, constipation and other abdominal disordersKirtikar and Basu, 1935; Arya, 1994). Reports suggest that, alco-olic extract of Cucumis trigonus fruit is shown to possess variousctivities such as anabolic activity (Mainkar et al., 1986), anal-

esic, anti-inflammatory and diuretic activity (Naik et al., 1980,981). However, the literature indicates that there is no scien-ific evidence to support the antidiabetic effect of Cucumis trigonus.he present study investigates the action of aqueous extract ofucumis trigonus fruits in the different models of rats to ascertain

∗ Corresponding author at: Department of Pharmacognosy and Phytochemistry,LE University, JNMC Campus, Nehru Nagar, Belgaum 10, Karnataka, India.el.: +91 9986409304; fax: +91 8312472387.

E-mail address: salahuddin md08@rediffmail.com (Md. Salahuddin).

378-8741/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved.oi:10.1016/j.jep.2009.10.018

rofile of STZ-induced-diabetic rats.© 2009 Elsevier Ireland Ltd. All rights reserved.

the scientific basis for the use of these plants in the treatment ofdiabetes.

2. Materials and methods

2.1. Collection of plant material

The fruits of Cucumis trigonus were collected during November2007 from the Western ghats, Karnataka, India. The leaves wereidentified by Dr. Harsha Hegde, Research Officer, RMRC, ICMR, Bel-gaum, Karnataka, India. A voucher specimen (SA-02) has been keptin herbarium in the Department of Pharmacognosy, KLE University,Belgaum, Karnataka, India.

2.2. Preparation of the test samples

Cucumis trigonus fruits were cut into small pieces and were

allowed to dry in the shade. About 100 g of the dried material washot extracted at 60 ◦C for 6 h using 1 L of water, and the waterextract was filtered, and evaporated for dryness under vacuum,which yielded a sticky material (yield: 26.1%, w/w) (Jain, 1968;Latha and Pari, 2004; Aslan et al., 2007).

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66 Md. Salahuddin, S.S. Jalalpure / Journal

.3. Preliminary phytochemical screening

Preliminary phytochemical screening (Kokate, 1994; Harborne,998) revealed the presence of carbohydrates, proteins and aminocids.

.4. Animals

Healthy Wistar rats between 2 and 3 months of age, and weigh-ng 180–200 g were used for the study. The study was approvedy the Institutional Animal Ethical Committee of Jawaharlal Nehruedical College, Belgaum, India (Resolution No. 1/16/2007).

.5. Acute toxicity studies

The acute oral toxicity study was carried out according to theuidelines set by OECD. Starting dose was selected to be 2000 mg/kg.w. and finally a dose of 5000 mg/kg b.w. was evaluated for toxicity.

.6. Effect of aqueous extract in normoglycemic rats (NG)

Animals in the control group received normal saline (orally).he test group of animals was treated with the aqueous extractf Cucumis trigonus fruits at a predetermined therapeutic dose of00 mg/kg per oral. Blood samples were collected at 30, 60 and20 min, after the administration (Shirwaikar and Rajendran, 2006;slan et al., 2007).

.7. Oral glucose tolerance test in normal rats (OGTT)

Rats were divided into two groups (n = 6) and were adminis-ered normal saline and dose of 500 mg/kg per oral of aqueousxtract. Glucose solution 2 g/kg was administered 30 min after thedministration of the extract. Blood samples were withdrawn frometro-orbital at intervals of 30, 60 and 120 min of glucose adminis-ration (Shirwaikar and Rajendran, 2006; Aslan et al., 2007).

.8. Evaluation of antidiabetic activity

.8.1. Induction of diabetesDiabetes was induced in rats by intraperitoneal (i.p.) injection

f STZ at a dose of 70 mg/kg body weight, dissolved in 0.1 M colditrate buffer (pH = 4.5) (Brain et al., 1997; Kadnur and Goyal, 2005).

.8.2. Chronic treatment modelRats were divided into four groups of six rats (n = 6) each.

roups 1 & 2 served as control and diabetic untreated controlespectively. Group 3 served as standard and was treated with.25 mg/kg/day glibenclamide (Sun Pharmaceuticals Ltd., India).

roup 4 was treated with the aqueous extract of Cucumis trigonus

ruits at of 500 mg/kg per oral/day for 21 days. Blood glucose lev-ls and body weight were measured on day 1, 7, 14 and 21 of thetudy. Finally on day 21, blood was collected to perform variousarameters (Latha and Pari, 2004; Chakrabarti et al., 2005).

able 1ffect of aqueous extract of Cucumis trigonus fruit on serum glucose level.

Group (n = 6) Treatment Fasting pla

1st day

I Normal control 77.5 ± 4.II Diabetic control 259.3 ± 7.III Diabetic + glibenclamide (0.25 mg/kg) 294.5 ± 11IV Diabetic + aqueous extract (500 mg/kg) 431.3 ± 20

alues are given as mean ± S.E.M. from six rats in each group.*** P < 0.001 significant from normal and diabetic control animals.

nopharmacology 127 (2010) 565–567

2.9. Statistical analysis

The results are expressed as mean ± S.E.M. Statistical differencewas tested by using one-way analysis of variance (ANOVA) fol-lowed by Student’s t-test. A difference in the mean P value <0.05was considered as significant.

3. Results

3.1. Acute toxicity study

The various observations showed the normal behaviour of thetreated rats. No toxic effects were observed at a higher dose of5 g/kg body weight. Hence, there were no lethal effects in any ofthe groups.

3.2. Hypoglycemic effect of aqueous extract

The results from the study clearly indicated that the aqueousextract exhibited significant hypoglycemic activity in STZ-diabeticrats, whilst there was no significant effect observed on normo-glycemic rats. However, at the end of 21 days of treatment, therewas a 56.39% decrease (P < 0.001) of serum glucose levels with theaqueous extract (Table 1). The standard drug glibenclamide alsoindicated a significant decrease (28.13%) of serum glucose levels.

3.3. Changes in body weight

At the end of 21 days treatment, the body weight of normalrats, aqueous extract and standard drug treated group, increasedsignificantly (P < 0.001) by 24.35%, 15.10% and 35.12% whereas thebody weight of diabetic control group decreased by 27.82%.

3.4. Changes of serum insulin, liver glycogen and glycosylatedhemoglobin

After 21 days treatment period, it was observed that the ani-mals treated with aqueous extract showed a significant increasein the serum insulin level (50%), liver glycogen level (130%) andglycosylated hemoglobin level (41%).

3.5. Changes of creatinine, hemoglobin and urea

The results of the study have indicated that there was no signif-icant increase in the serum creatinine level in the aqueous extracttreated group. However, when compared to the diabetic control,the aqueous extract treatment indicated a significant increase of16% in hemoglobin level and a significant decrease (P < 0.001) of30% in the urea level.

3.6. Lipid profile

When compared to the diabetic control rats, significant(P < 0.001) reductions of 37.99% CHL (cholesterol), 57.21% LDL (low

sma glucose concentration (mg/dl)

7th day 14th day 21st day

3 86.1 ± 3.8 91.5 ± 1.2 89.5 2 ± 4.34 355.5 ± 18.1 400.7 ± 10.0 390.0 ± 6.3.0 378.0 ± 32.9 308.2 ± 2.6 212.2 ± 6.8***

.5 267.7 ± 13.5 219.5 ± 26.3 188.3 ± 20.3***

Md. Salahuddin, S.S. Jalalpure / Journal of Eth

Fig. 1. Effect of aqueous extract of Cucumis trigonus fruit on serum lipid profile.Tlf*

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Shirwaikar, A., Rajendran, K., 2006. Effect of aqueous bark extract of Garuga pinnataRoxb. in streptozotocin–nicotinamide induced type-II diabetes mellitus. Journal

GL: triglycerides; CHL: cholesterol; HDL: high density lipoprotein; LDL: low densityipoprotein; VLDL: very low density lipoprotein. Values are given as mean ± S.E.M.rom six rats in each group. * P < 0.05 significant, **P < 0.01 most significant,*P < 0.001 highly significant from diabetic.

ensity lipoprotein), 34.46% VLDL (very low density lipoprotein)nd 28.18% TGL (triglyceride) were found after treatment of aque-us extract of Cucumis trigonus fruit. Also, there was a significantP < 0.05) increase of HDL (high density lipoprotein) cholesterol inhe treated diabetic rats. In the case of untreated diabetic rats, thereas a fall in HDL level (Fig. 1).

. Discussion and conclusion

The present manuscript discusses about the hypoglycemic andntidiabetic effects of the aqueous fruit extract of Cucumis trigonusn normal and streptozotocin-induced-diabetic rats. Acute toxicitytudies revealed the non-toxic nature of the aqueous fruit extractf Cucumis trigonus. There was no lethality or any toxic reactionsound with the selected dose until the end of the study period. Theose of the test drug has been selected on the basis of dose calibra-ion curve. The results of the study have shown that the aqueousxtract of fruit at a dose of 500 mg/kg body weight has a markedypoglycemic activity by improvement of the glucose tolerance test

n normoglycemic rats and by lowering the blood glucose levels inTZ-induced-diabetic rats.

The results of the study have shown a significant (P < 0.001) dif-erence between the initial and final fasting plasma glucose levelsf aqueous fruit extract Cucumis trigonus and glibenclamide treatedroups (Table 1). Induction of diabetes by STZ leads to loss of bodyeight due to the increased muscle wasting and loss of tissue pro-

eins (Swanston-Flat et al., 1990; Chatterjee and Shinde, 2002). Theesults obtained with the aqueous extract treatment in chronic dia-etic model further clarified the antidiabetic effect of the extract.fter 21 days of aqueous extract treatment, gain in the body weightas observed in diabetic rats and the results were comparable with

hat of the standard drug glibenclamide.Aqueous extract of Cucumis trigonus showed significant increase

n serum insulin level. A marked decrease in triglycerides, totalholesterol, LDL and VLDL was observed, while increase in HDLholesterol has been observed in aqueous fruit extract treated dia-etic rats which suggest that HDL is inversely related to the totalody cholesterol (Fig. 1) (Reshma and Sushma, 2002). The possi-

le mechanism of antidiabetic action of aqueous extract may be by

ncreasing the pancreatic secretion of insulin from the existing betaells, by its release from the bound form.

Animals treated with aqueous extract indicated a significantecrease in the glycosylated hemoglobin level which could be

nopharmacology 127 (2010) 565–567 567

due to an improvement in insulin secretion, whereas glycosy-lated hemoglobin level increased significantly in untreated diabeticcontrol group, which confirms the antidiabetogenic action of theextract (Hall et al., 1984). The significant increase was observed inglycogen levels of the aqueous fruit extract treated diabetic ani-mals. The extract did not produce any significant effects on normalanimals.

In conclusion, it can be stated, that the aqueous fruit extractof Cucumis trigonus has beneficial effects, in reducing the elevatedblood glucose level and lipid profile of STZ-induced-diabetic rats,but has no effect on normal rats. Thus, justifying the claim made byAyurvedic classics.

Acknowledgements

The authors sincerely thank Dr. F. V. Manvi, Principal, KLE Uni-versity’s College of Pharmacy for providing the necessary facilitiesand U.G.C. New Delhi for financial assistance provided (10-26/2005(SA-I)) for this work.

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