Inhibitory Effect of α-Glucosidase Inhibitors Varies According to Its Origin

Abstract

The inhibitory effect of alpha-glucosidase (AGH) inhibitors against its origins (baker's yeast and rat, rabbit, and pig small intestines) was investigated. All inhibitors used in this study showed quite different inhibitory activities according to AGH origins. Voglibose, acarbose and glucono-1,5-lactone strongly inhibited mammalian AGHs, whereas no or less inhibition was observed in yeast AGH. On the contrary, (+)-catechin, a good inhibitor against yeast AGH (IC(50) = 1.3 x 10(-)(1) mM) as well as voglibose (IC(50) = 2.6 x 10(-)(2) mM), did not retard the mammalian AGH activity. Subsequent inhibition study with various food components revealed that all of foods except for green (IC(50) = 0.735 mg/mL) and oolong teas (IC(50) = 1.34 mg/mL) showed no inhibitory activity against rat AGH, whereas they inhibited yeast AGH. Consequently, the magnitude of AGH inhibition was greatly affected by its origin, and more attention relating to AGH origin would be needed to evaluate in vitro AGH inhibitory effect.

Hypoglycemic and Antioxidative Effects of <i>Glossogyne tenuifolia</i> on Streptozotocin-Nicotinamide-Induced Diabetic Rats

“…Type-I α-glucosidase, derived from yeast, is usually of higher purity, while α-glucosidase, derived from rat small intestine, Type-II, mimics mammals more [27]. Inhibition ability of acarbose for type-II α-glucosidase is superior to that of type-I [17]; similar results were found in our experiment.…”

“…The inhibition for α-glucosidase from yeast and rat intestine were measured according to Kim et al [16] and Oki et al [17], respectively as modified by Elya et al [18]. Alternatively, test samples (the extracts and acarbose) were dissolved in 0.1 M phosphate buffered saline (PBS) (pH 6.8), after filtration, 600 µL of each solution were added to 120 μL 0.2 U/mL α-glucosidase and 120 μL 0.1 M PBS (pH 6.8).…”

Alpha glucosidase inhibitory effect and enzyme kinetics of coastal medicinal plants

“…Earlier studies, most mammalian -glucosidase inhibitors did not effectively inhibit microbial -glucosidases (Oki et al, 1999), because plants and mammalian enzymes are maltostructure, it hydrolyze homogeneous substrate whereas bacterial, yeast, and insect enzymes are maltooligosaccharides show higher activity toward heterogeneous substrates such as sucrose and pNPG, and no activity toward homogeneous substrates (Kimura, 2002;Kimura et al, 2004). Our present result exhibits the strong enzymatic inhibitory activity against yeast -glucosidases shown by three plant extracts (A. marmelos, C. colocynthis and I. pes-caprae) is obviously enhanced than the commercial inhibitor acarbose at low concentration.…”

Tryptophan-containing milk protein-derived dipeptides inhibit xanthine oxidase

“…Trp has been described for its central role as a precursor of biomolecules such as melatonin, serotonin and dynorphin [22,39] and for its antioxidant properties [48,60]. Similarly, Val-Trp has been associated with various bioactive properties including angiotensin-converting enzyme (ACE) inhibition [6,37,64,67,74,89,91,93,94] and for -glucosidase inhibition [58,66]. The reverse peptide Trp-Val has also been described as an ACE inhibitor [67] and an anti-oxidant [31].…”