Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters










Database
Language
Publication year range
1.
BMC Complement Altern Med ; 13: 39, 2013 Feb 20.
Article in English | MEDLINE | ID: mdl-23425283

ABSTRACT

BACKGROUND: One vital therapeutic approach for the treatment of type 2 diabetes mellitus is the use of agents that can decrease postprandial hyperglycaemia by inhibiting carbohydrate digesting enzymes. The present study investigated the effects of bioassay-guided extract and fractions of the dried fruit pericarp of Phaleria macrocarpa, a traditional anti-diabetic plant, on α-glucosidase and α-amylase, in a bid to understand their anti-diabetic mechanism, as well as their possible attenuation action on postprandial glucose increase. METHODS: Methanol extract (ME), obtained by successive solvent extraction, its most effective liquid-liquid n-butanol fraction (NBF) and the flash column chromatographic sub-fraction (SFI), were evaluated for in vitro α-glucosidase (yeast) and α-amylase (porcine) activity inhibition. Furthermore, confirmatory in vivo tests were carried out in streptozotocin-induced diabetic rats (SDRs) using oral glucose, sucrose and starch tolerance tests. RESULTS: At the highest concentration employed (100 µg/ml), NBF showed highest inhibition against α-glucosidase (75%) and α-amylase (87%) in vitro (IC50 = 2.40 ± 0.23 µg/ml and 58.50 ± 0.13 µg/ml, respectively) in a dose-dependent fashion; an effect found to be about 20% higher than acarbose (55%), a standard α-glucosidase inhibitor (IC50 = 3.45 ± 0.19 µg/ml). The ME and SFI also inhibited α-glucosidase (IC50 = 7.50 ± 0.15 µg/ml and 11.45 ± 0.28 µg/ml) and α-amylase (IC50 = 43.90 ± 0.19 µg/ml and 69.80 ± 0.25 µg/ml), but to a lesser extent. In in vivo studies with diabetic rats, NBF and SFI effectively reduced peak blood glucose (PBG) by 15.08% and 6.46%, and the area under the tolerance curve (AUC) by 14.23% and 12.46%, respectively, after an oral sucrose challenge (P < 0.05); thereby validating the observed in vitro action. These reduction effects on PBG and AUC were also demonstrated in glucose and starch tolerance tests, but to a lesser degree. CONCLUSIONS: These findings reveal that P. macrocarpa can attenuate hyperglycaemia in both in vitro and in vivo conditions by potently inhibiting carbohydrate hydrolysing enzymes, making it a viable plant for sourcing natural compounds for the management of type 2 diabetes mellitus.


Subject(s)
Diabetes Mellitus, Experimental/drug therapy , Dietary Carbohydrates/metabolism , Glycoside Hydrolase Inhibitors , Hyperglycemia/prevention & control , Plant Extracts/therapeutic use , Thymelaeaceae , alpha-Amylases/antagonists & inhibitors , Animals , Area Under Curve , Blood Glucose/metabolism , Diabetes Mellitus, Experimental/enzymology , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 2/drug therapy , Digestion/drug effects , Dose-Response Relationship, Drug , Fruit , Hyperglycemia/metabolism , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Male , Plant Extracts/pharmacology , Rats , Rats, Sprague-Dawley , Sucrose/metabolism
2.
Molecules ; 17(5): 4986-5002, 2012 Apr 30.
Article in English | MEDLINE | ID: mdl-22547320

ABSTRACT

An earlier anti-hyperglycemic study with serial crude extracts of Phaleria macrocarpa (PM) fruit indicated methanol extract (ME) as the most effective. In the present investigation, the methanol extract was further fractionated to obtain chloroform (CF), ethyl acetate (EAF), n-butanol (NBF) and aqueous (AF) fractions, which were tested for antidiabetic activity. The NBF reduced blood glucose (p < 0.05) 15 min after administration, in an intraperitoneal glucose tolerance test (IPGTT) similar to metformin. Moreover, it lowered blood glucose in diabetic rats by 66.67% (p < 0.05), similar to metformin (51.11%), glibenclamide (66.67%) and insulin (71.43%) after a 12-day treatment, hence considered to be the most active fraction. Further fractionation of NBF yielded sub-fractions I (SFI) and II (SFII), and only SFI lowered blood glucose (p < 0.05), in IPGTT similar to glibenclamide. The ME, NBF, and SFI correspondingly lowered plasma insulin (p < 0.05) and dose-dependently inhibited glucose transport across isolated rat jejunum implying an extra-pancreatic mechanism. Phytochemical screening showed the presence of flavonoids, terpenes and tannins, in ME, NBF and SFI, and LC-MS analyses revealed 9.52%, 33.30% and 22.50% mangiferin respectively. PM fruit possesses anti-hyperglycemic effect, exerted probably through extra-pancreatic action. Magniferin, contained therein may be responsible for this reported activity.


Subject(s)
Diabetes Mellitus, Experimental/drug therapy , Fruit/chemistry , Phytotherapy , Plant Extracts/administration & dosage , Thymelaeaceae/chemistry , Animals , Biological Assay , Biological Transport , Blood Glucose/analysis , Chemical Fractionation , Diabetes Mellitus, Experimental/metabolism , Female , Glucose Tolerance Test , Glyburide/administration & dosage , Glyburide/chemistry , Glyburide/therapeutic use , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/therapeutic use , Insulin/blood , Jejunum/metabolism , Male , Metformin/administration & dosage , Metformin/chemistry , Metformin/therapeutic use , Methanol/chemistry , Plant Extracts/chemistry , Plant Extracts/therapeutic use , Rats , Rats, Sprague-Dawley , Solvents/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...