In vivo acute effects of orally administered hydro-ethanol extract of catha edulis on blood glucose levels in normal, glucose-fed hyperglycemic, and alloxan-induced diabetic rats

To investigate the blood glucose lowering effect of khat [Catha edulis] extract in normal, glucose-loaded, and alloxan diabetic rats. Three experimental protocols were used in this study. In each of the first 2 protocols, 3 groups of rats [6 rats per group] were used as control group [NS], Catha edulis [CE] treated, and glibenclamide treated groups. This study was carried out at the Physiological Laboratory of the Medical School of King Khalid University, Abha, Saudi Arabia between October and November, 2009. Normal rats were used in the first protocol while alloxan diabetic rats were used in the second protocol. Blood glucose levels were measured in all 3 groups after single dose injections of saline, CE or glibenclamide. In the third protocol, another 6 groups of rats [6 rats per group] were prepared as in the first 2 protocols and oral glucose tolerance test [OGTT] was performed on each rat after oral administration of glucose [1.5g/kg]. Oral administration of a hydro-ethanol extract of CE caused no statistically significant change in blood glucose levels in normal rats with or without glucose loading. There were slight, non significant increases in blood glucose levels of extract-treated diabetic rats, with and without glucose loading, as compared to the corresponding untreated rats. Oral administration of CE extract does not exert a hypoglycemic effect in normal, glucose-loaded, and diabetic rats

Antioxidant activity for a novel phenolic glycoside from koelreuteria elegans

Reactive oxygen species [ROS] have been implicated in the pathophysiology of many diseases such as atherosclerosis, Alzheimer's and Parkinson's diseases. Additional evidence also suggests ROS may play a role in the decline in neuronal function during normal aging. Phytochemical investigation of koelreuteria elegans resulted in isolation of a new benzoic acid monoglycoside, its structure was established as: benzoic acid 4-0-alpha-L-arabinopyranoside [compound 1] which exhibited strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generation. Three other known flavonol glycosides; quercetin-3-O-alpha-L-arabinopyranside [compound 2], kaempferol-3-O-alpha-L-arabinopyranoside [compound 3] and ombuin 3-O-alpha-L-rharnnopyranosyl-6-D-glucopyranosyl [compound 4], in addition to a triterpene saponin 3-O-beta-D-glucopyranosyl[1-2][alpha-L-rhamnopyranosyl[1-3]] beta-D-glucuronopyranosyl 28-0-angeloyl-camelliagenin A [comped 5] were also isolated