Antihyperglycemic Effect of Constituents fromHintonia standleyanain Streptozotocin-Induced Diabetic Rats

Abstract

An extract (100 mg/kg) of the stem bark of Hintonia standleyana caused a significant decrease in blood glucose levels in both normal and streptozotocin (STZ)-diabetic rats when compared with vehicle-treated groups (p < 0.05). From the active extract, 3- O- beta- D-glucopyranosyl-23,24-dihydrocucurbitacin F ( 1), 5- O-beta- D-glucopyranosyl-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin ( 2) and 5- O-[ beta- D-apiofuranosyl-(1-->6)- beta- D-glucopyranosyl]-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin ( 3) were isolated. Coumarin 3 is a new natural product and was identified by spectroscopic methods. Compounds 1 and 3 did not decrease blood glucose levels in normal rats. However, in two different long-term subacute experiments, using animals with a developing diabetes condition and with STZ-induced diabetes, both compounds at daily doses of 10 mg/kg (developing diabetes condition) or 30 mg/kg (STZ-induced diabetes condition) provoked a significant antihyperglycemic activity (p < 0.05). Furthermore, compound 3 restored normal blood glucose levels in STZ-induced diabetic rats. In all cases, the groups treated with the active principles and the extract showed less body weight lost than the glibenclamide-treated and diabetic control groups (p < 0.05). These results showed that the antihyperglycemic active principles of H. standleyana are both 4-phenylcoumarins and cucurbitacin glycosides.

Antihyperglycemic, Antihyperlipidemic and Antiapoptotic Activities of Micromelum minutum Seeds in Diabetic Rats

“…The administration of both Micromelum minutum seeds extract and Microminutinin coumarin Micromelum minutum seeds extract and Microminutinin coumarin to diabetic rats decrease body weight. These results are in agreement with that of Pari and Rajarajeswari [42] and Guerrero-Analco et al [35] who reported that the administration of coumarin to diabetic rats resulted in alterations in the metabolism of glucose with subsequent reduction in plasma glucose levels and body weight.…”

“…Coumarins also inhibited lipid peroxidation and increased the activity of antioxidants, superoxide dismutase and catalase [34]. Micromelum minutum seeds extract significantly reduced the blood glucose levels of diabetic rats indicating that the mechanism of action may be due to coumarin ingredient; where coumarin inhibits hyperglycemia [34,35]. Hyperglycemia inhibits antioxidants and its cellular transport.…”

Development and Validation of Liquid Chromatography Method for Quantification of the Active Markers ofHintonia standleyana. andHintonia latiflora. Crude Drugs

“…1) were isolated from the stem-bark of H. standleyana and H. latiflora, respectively, as previously described (Guerrero-Analco, et al, 2005. Their purity was verified by HPLC and RMN.…”

“…Recently, we have studied the antidiabetic potential of H. standleyana and demonstrated that the extracts (50 mg/kg) or active compounds (15 mg/kg each time), twice a day during 30 days, provoked a significantly antihyperglycemic effect in streptozotocin-diabetic rats, restoring blood glucose levels near to or to normal values (Guerrero-Analco et al, 2005. Furthermore, this work demonstrated that the active principles of the Mexican copalchis were not only 4-phenylcoumarin glycosides but also cucurbitacins (Guerrero-Analco et al, 2005).…”

“…Recently, we have studied the antidiabetic potential of H. standleyana and demonstrated that the extracts (50 mg/kg) or active compounds (15 mg/kg each time), twice a day during 30 days, provoked a significantly antihyperglycemic effect in streptozotocin-diabetic rats, restoring blood glucose levels near to or to normal values (Guerrero-Analco et al, 2005. Furthermore, this work demonstrated that the active principles of the Mexican copalchis were not only 4-phenylcoumarin glycosides but also cucurbitacins (Guerrero-Analco et al, 2005). Other pharmacological studies have demonstrated the antimicrobial (Rojas et al, 1992), antiplasmodial (Noster & Kraus, 1990;Köler et al, 2001), and antinociceptive (Déciga-Campos et al, 2006) properties of different extracts and metabolites from H. latiflora and H. standleyana.…”