Determination of glucose generation rate from various types of glycemic carbohydrates by mammalian glucosidases anchored in the small intestinal tissue.

The supernatant from rat intestinal acetone powder (RIAP) was used as a source of mammalian glucosidases to determine the digestion properties of glycemic-carbohydrates. We hypothesized that many glucosidases are still anchored to the precipitated-intestinal tissues with available enzymes, and developed a method using the RIAP suspension to optimize the in vitro carbohydrate digestion model. The glucose production from various types of glycemic ingredients by RIAP suspension showed that this carbohydrate-hydrolysis model using the entire spectrum of glucosidases can be applied in an in vitro assay to determine carbohydrate quality from glycemic food products at the mammalian level. This approach better mimics the mammalian situation compared to other assays to determine the glycemic-carbohydrate digestion properties that employ fungal/microbial glucosidases that have different hydrolytic activities compared to mammalian enzymes. The method can also be used to determine the inhibitory effects of α-glucosidase inhibitors to attenuate the post-prandial blood glucose level.

Enzymatically elongated rice starches by amylosucrase from Deinococcus geothermalis lead to slow down the glucose generation rate at the mammalian α-glucosidase level.

Amylosucrase (AS) catalyzes the transfer of a glucosyl unit from sucrose onto α-1,4-linked glucan polymers in starch. In this study, AS from Deinococcus geothermalis (DgAS) was applied to produce modified rice starches with slowly digestible properties. DgAS-treated waxy and normal rice starches showed significantly (p < 0.05) elevated degrees of polymerization, suggesting that the external chains were elongated. Additionally, the crystalline structures of starches changed from A- to B-type, and the temperature transition properties of enzymatically modified rice starches increased. The amounts of slowly digestible starch (SDS) increased remarkably (20.1% and 18.8%; waxy and normal rice starches, respectively), and the DgAS-treated rice starches were slowly hydrolyzed to glucose at the mammalian mucosal α-glucosidase level. Thus, DgAS-treated rice starches can be used to produce SDS-based ingredients that attenuate the glucose spike after glycemic food ingestion.

Different inhibition properties of catechins on the individual subunits of mucosal α-glucosidases as measured by partially-purified rat intestinal extract.

Mucosal α-glucosidases from rat intestinal powder were employed, with a step to remove α-amylase, to measure the possibility of different inhibition of catechins, particularly those found in tea, on the four α-glucosidase enzymes. Inhibition of catechins was investigated for the slowing of digestion of glycemic carbohydrates, thus regulating glucose release and absorption. The α-glucosidases were fractionated using size-exclusion chromatography. The partially purified fractions showed higher α-glucosidase activity without any α-amylase activity. Catechins had selective inhibition properties on the α-glucosidases. In particular, (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin gallate (ECG) showed comparably high inhibitory effect on all four individual α-glucosidases, while (-)-epicatechin (EC), and (+)-catechin (C) indicated a more discriminating effect with relatively higher inhibitory effects on sucrase-isomaltase. The findings suggest that catechins differently inhibit the individual subunits of the α-glucosidases, and that they could modulate postprandial blood glucose levels through slowing digestion rate of starch and other glycemic carbohydrates, including sucrose.

Effects of raw potato starch on body weight with controlled glucose delivery.

Starch digestion in the gastrointestinal tract has different properties depending on its botanical source. In this study, corn, wheat, rice, and potato starches were used to test the digestion properties of mammalian mucosal α-glucosidase in an in vitro assay, and their physiological effects were investigated in male C57BL/6 mice. The results clearly demonstrated that potato starch caused the lowest rates of glucose generation, suggesting that it can attenuate the postprandial glucose spike. Interestingly, a potato starch-based diet caused significantly (P < 0.05) lower weight gain and fat accumulation compared to diets based on other starches, through increased insulin sensitivity. This result suggests that potato starch-based products can be used to regulate postprandial blood glucose levels, aiding in the control of metabolic diseases.

Displaced fracture of the coracoid process associated with acromioclavicular dislocation: a two-bird-one-stone solution.

We describe a surgical treatment for a displaced fracture of the coracoid process associated with acromioclavicular dislocation. This treatment involves fixing the coracoid process using a cannulated screw without acromioclavicular fixation under fluoroscopic guidance. The benefits of this treatment are that fixation with a cannulated screw simultaneously reduces both the displaced fracture of the coracoid process and the acromioclavicular joint via the intact coracoclavicular ligament, thus reducing the complications associated with transacromial pin fixation.