ANTIDIABETIC ACTIVITY OF METHANOLIC EXTRACT OF MEMECYLON MALABARICUM COGN (MELASTOMATACEAE) LEAVES

Memecylon malabaricum cogn (Melastomataceae) is an indigenous medicinal plant used in ethno medicine for the treatment of bacterial infections, inflammation and skin diseases including herpes, chickenpox. It’s also a root ecbolic. The methanolic extract of Memecylon malabaricum leaves is subjected to antidiabetic activity using experimental model of alloxan induced diabetes. The results showed that the methanolic extract at the dose of 400 mg/kg body weight showed significantly decreased (P<0.01) of the raised blood glucose level, comparable to reference standard, gliclazide. The preliminary phytochemical analysis reveals that the plant possessing steroids, saponins, flavonoids, tannins, and alkaloids. The antidiabetic activity of the plant may be due to the presence of the above said category of compounds. It is therefore worth study further to isolate the pure molecules responsible for antidiabetic activity. In conclusion, the results of this study explicate justification of the use of this plant in the treatment of diabetes.


IJPP VOL 2 ISSUE 1
Memecylon malabaricum has considerable reputation for its traditional use in the treatment of diabetes, various bacterial infections, inflammatory and skin disorders including herpes, chicken pox. It is also used as a root ecbolic like ergot 14, 15 . Although this herb has many useful claims, no specific scientific study has been carried out to examine the antidiabetic activity of the plant, that's why the current study was designed.

Material and methods Experimental Animals:
Wistar albino rats of either sex (200-250 g) procured from National Institute of Nutrition, Hyderabad, Andhra Pradesh, India, and were used to study the antidiabetic activity. The rats were randomly distributed into groups and housed in cages (5 per cage). The animals were maintained under standard laboratory conditions (light period of 12h/day and temperature 22 0C±20C), with free access to standard rodent pellet diet (Amrut, India) and water ad libitium. The experiment was cleared by Institutional Animal Ethical Committee.

2.3Plant Material:
Fresh leaves of Memecylon malabaricum were collected from Western Ghats of India in November 2008 and were authenticated from Prof. M. Venkaiah, Taxonomist, Department of Botany, Andhra University, Visakhapatnam, India. The leaves were shade dried at a temperature between 21-30 0 C for 15-30 days, after which these leaves were chopped and ground. Finally extraction was carried out by the following procedure 2.4 Preparation of the Extract: The powdered crude drug (700 g) was extracted with methanol in Soxhlet apparatus for 24 hours. The extract thus obtained was concentrated under vacuum (50 0 C) dried completely and weighed. The yield was found to be approximately 16% w/w.  16: Albino rats of either sex were fasted for 18h before injection with alloxan. Alloxan monohydrate was dissolved in saline. A dose of 100 mg/kg body weight injected immediately after preparation through intraperitoneal route. Since alloxan is capable of producing fatal hypoglycaemia as a result of massive insulin release from the pancreas, animals were treated with 10% dextrose orally to combat the immediate hypoglycaemia. Blood sugar was measured after 24-48 h of alloxan treatment to evaluate induction of diabetes.

Collection of Blood Samples:
The animal was restrained (un anaesthetized) in such a way that loose skin of the neck was tightened while handling the head with the left hand. With the help of the index finger the eye was pressed just behind the angle of the jaw resulting in the engorgement of the retro orbital plexus. Then tip of the capillary was inserted at the medial canthus into the retro-orbital plexus with gentle rotation by the other hand. As the vessels are ruptured, blood wells up in the periorbital space. The tip of the capillary was then slightly withdrawn, so that the blood flows into the capillary, which was collected in micro centrifuge tube containing small quantity of potassium oxalate and sodium fluoride as anticoagulant. Blood samples were collected from retro-orbital plexus at 0, 1, 2, 4, 6, 8, 10, and 12 hour. Blood glucose levels were estimated by GOD-POD method.

Statistical analysis
Results of the study were expressed as Mean ± S.E.M. ANOVA followed by Dennett's test were used to determine significant differences between groups. P-Values less than 0.05 and 0.01 were considered as indicative of significance

Results
The antidiabetic activity of methanolic extract of Memecylon malabaricum leaves against alloxan induced diabetic rats was presented in table 02 and fig. 01. Memecylon malabaricum which showed antidiabetic activity and the results are comparable to that of Gliclazide. The extract at 400 mg/kg, p.o, showed maximum reduction of raised blood glucose level as that of 100 and 200 mg/kg. The results obtained indicates that the extract found to have significant (P<0.01) antidiabetic activity in rats.

Discussion
The crude methanol extract showed presence of multiple chemical constituents with the presence of flavonoids, saponins, tannins. The extract showed dose dependent antidiabetic activity, which was found to be statistically significant at higher concentration in alloxan induced diabetes. However this activity was less potent as compared to Gliclazide.

Conclusion
Memecylon malabaricum extract possesses an antidiabetic activity. Further studies are required to identify the active fractions that are responsible for antidiabetic activity and to clarify mechanisms of their actions.