Antioxidant and antiglycation properties of total saponins extracted from traditional Chinese medicine used to treat diabetes mellitus

Abstract

Eleven antidiabetic traditional Chinese medicine (TCM) extracts rich in saponins were examined for their antioxidant and antiglycation activities. The antioxidant activities of these extracts were evaluated by studying the inhibition of lipid peroxidation in rat liver microsomes induced by ascorbate/Fe2+, cumine hydroperoxide (CHP) or CCl4/reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH). The antioxidant capacities were also evaluated by studying the scavenging of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical. The antiglycation activities of these extracts were evaluated by hemoglobin-delta-gluconolactone (delta-Glu) assay, bovine serum albumin (BSA)-glucose assay and N-acetyl-glycyl-lysine methyl ester (GK peptide)-ribose assay. Aralia taibaiensis outperformed other extracts in most of the assays except inhibition of early glycation products formation, where Acanthopanax senticosus showed higher activity. Aralia taibaiensis was particularly potent in inhibiting the late glycation and formation of advanced glycation end products (AGEs) on proteins. The antioxidant and antiglycation activities of most extracts were correlated with the saponin content. The results demonstrate that the antidiabetic activities of most extracts could be explained, at least in part, by their combined antioxidant and antiglycation properties.

Clerodendron glandulosum Coleb., Verbenaceae, ameliorates high fat diet-induced alteration in lipid and cholesterol metabolism in rats

“…The quantitative phytochemical analysis of C. glandulosum leaves for saponins (Xi et al, 2007), phytosterols (Goad & Akihisa, 1997), ascorbic acid (Barakat et al, 1973), polyphenols (Yen & Hsieh, 1998) and flavanoids was carried out.…”

In vitro antidiabetic effects of selected fruits and vegetables against glycosidase and aldose reductase

“…Moreover, because of the significant roles of oxidation reactions in advanced glycated end products (AGE) formation, the antioxidant poses hypoglycemic effect through anti‐AGE mechanism (Xi et al. 2010). The food with high antioxidant content often recommended to the diabetic patients.…”

Production of a highly potent epoxide through the microbial metabolism of 3β-acetoxyurs-11-en-13β,28-olide by Aspergillus niger culture

“…Antiglycation activity was determined using a previously described method with appropriate modifications (Xi et al 2008). Briefly, to 250 mL of bovine serum albumin (1 mg/mL), an equal amount of 500 mM glucose was added.…”