THE HYPOGLYCAEMIC EFFECT OF OLEANONIC ACID ISOLATED FROM PILEA ELIZABETHAE IN A RAT MODEL

Objective: The objective of this study is to isolate and identify the chief hypoglycaemic component of Pilea elizabethaeMethods: The chief hypoglycaemic component of Pilea elizabethaewas isolated and identified. The bio-directed purification of the chief hypoglycaemic agents contained in Pilea elizabethae followed a sequence of steps alternating oral glucose tolerance test (OGTT) bioassay and chromatographic methods. The ethyl acetate crude extract which was most hypoglycaemic in activity was flash chromatographed on silica gel using a gradient hexane-ethyl acetate solvent system of increasing polarity. Elucidation of the chemical structures of R-E2Gii was determined using NMR and FT-IR spectroscopy, melting point determination and comparison with literature. The Pilea elizabethae extracts were tested for hypoglycaemic activity in Sprague-Dawley albino rats using the oral glucose tolerance test (OGTT) method. Isolated hypoglycaemic compounds obtained after bio-directed purification were identified through nuclear magnetic resonance (NMR) spectroscopy and infra-red (IR) spectroscopy.Results: Bio-directed purification of Pilea elizabethae extracts yielded a hypoglycaemic principle that were coded R-E2Gii. By comparison of its NMR chemical shift values and physical properties with literature values, R-E2Gii found to be the triterpenoid oleanonic acid [C30H40O3; M. W=124]. The isolate R-E2Gii demonstrated significant hypoglycaemic activity. When administered intravenously, values were as low as 4.87±0.09 mmol/l thirty minutes post-load compared with 5.63±0.19 mmol/l for the control (p<0.006). An increase in dosage up to 10 mg/kg body weight amplified the post-prandial hypoglycaemic effect of R-E2Gii. Comparison of the hypoglycaemic effect of R-E2Gii with glibenclamide showed that the isolate was only mildly effective in reducing post-prandial hyperglycaemia. Hexane-ethyl acetate extracts from Pilea elizabethae was found to possess anti-hyperglycaemicactivity on OGTT.Conclusion: Bio-directed purification of the hexane-ethyl acetate extracts and using nuclear magnetic resonance (NMR) spectroscopy and infra-red (IR) spectroscopy revealed oleanonic acid, that may be responsible for the anti-hyperglycaemic properties of this extract.

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Phytochemical Screening, Physicochemical Properties, Acute Toxicity Testing and Screening of Hypoglycaemic Activity of Extracts ofEremurus himalaicusBaker in Normoglycaemic Wistar Strain Albino Rats

BioMed Research International ◽

10.1155/2014/867547 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 6

Author(s):

Ahlam Mushtaq ◽

Seema Akbar ◽

Mohammad A. Zargar ◽

Adil F. Wali ◽

Akhtar H. Malik ◽

...

Keyword(s):

Body Weight ◽

Glucose Tolerance ◽

Dose Level ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Phytochemical Screening ◽

Meoh Extract ◽

Hypoglycaemic Activity

In the present study EtOAc, MeOH, and aqueous extracts ofEremurus himalaicuswere evaluated for hypoglycaemic effect in normal rats using both oral glucose tolerance test and 14-day oral administration study. Phytochemical and physicochemical screening was also done. In oral glucose tolerance test the aqueous and MeOH extracts ofEremurus himalaicusat a dose level of 500 mg/kg body weight prior to glucose load resulted in a significant fall in blood glucose level within 150 min. of glucose administration. The aqueous extract at a dose level of 250 mg/kg body weight and 500 mg/kg body weight also showed good hypoglycaemic response (P< 0.001); this was followed by MeOH extract at a dose level of 500 mg/kg body weight (P< 0.05), while MeOH extract at dose level of 250 mg/kg body weight and ethyl acetate extract at dose level of 250 mg/kg body weight and 500 mg/kg body weight exhibited insignificant effect. Phytochemical screening of extracts revealed the presence of alkaloids, terpenoids, phenolics, tannins, saponins, cardiac glycosides, and flavonoids. The results indicate that aqueous extract possess significant hypoglycaemic activity in normoglycaemic rats which may be attributed to the above-mentioned chemical constituents.

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