chicoric-acid and Diabetes-Mellitus

Ocimum gratissimum and Ocimum basilicum are plants ethnopharmacologically used to treat diabetes mellitus, a life-threatening disease that affects millions of people worldwide. In order to further understand their antidiabetic potential, which has been previously demonstrated in animal models, we aimed to investigate the acute and chronic effects of major phenolic substances from both plants on insulin secretion and gene expression in pancreatic islets isolated from NMRI mice. Insulin secretion was measured after acute (1 h) and long-term (72 h) incubation of islets with one of four cinnamic acid derivatives (caftaric, caffeic, chicoric, and rosmarinic acids) or a C-glucosylated flavonoid (vicenin-2). All substances acutely enhanced glucose-stimulated insulin secretion (GSIS) from islets at concentrations from 10

Topics: Animals; Biological Transport; Cinnamates; Diabetes Mellitus; Female; Flavonoids; Gene Expression; Glucose; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Ocimum basilicum; Plant Extracts

Ocimum gratissimum L. is popularly used to treat diabetes mellitus. The hypoglycemic activity of this medicinal species has been confirmed by in vivo studies. The present study conducted a chemical investigation of a leaf decoction (10% p/v) of O. gratissimum monitored by in vivo hypoglycemic activity assays. Four phenolic substances were identified: L-caftaric acid (1), L-chicoric acid (2), eugenyl-β-D-glucopyranoside (3) and vicenin-2 (4). The acute hypoglycemic activity of the O. gratissimum decoction fractions Og1-S (300 mg/kg), Og1-A (240 mg/kg) and Og1-B (80 mg/kg) was evaluated intraperitoneally in normal and streptozotocin-induced diabetic mice. They reduced glycemia by 63%, 76% and 60% (in 120 min), respectively, in the diabetic mice. Subfractions of Og1-A were also evaluated under the same conditions: Og1-AS (200 mg/kg) and Og1-AP (40 mg/kg) produced a decrease of only 37% and 39%, respectively. Among the major phenolic substances, only chicoric acid (2; 3 mg/kg) reduced significantly the glycemic levels of diabetic mice by 53%, 120 min after treatment. This is the first study describing the hypoglycemic activity of chicoric acid in an animal model of diabetes mellitus. In addition, we suggest that there may be other substances contributing to this activity. Thus, for the first time, a correlation is established between the hypoglycemic activity of O. gratissimum and its chemical composition.

Topics: Animals; Caffeic Acids; Diabetes Mellitus; Drug Evaluation, Preclinical; Hypoglycemic Agents; Male; Mice; Ocimum; Phytotherapy; Plant Extracts; Plant Leaves; Succinates