Active Consumption of Konjac and Konjac Products Improves Blood Glucose Control in Patients with Type 2 Diabetes Mellitus.

OBJECTIVE: Konjac is a food mainly consumed in Asian countries with high fiber and low energy. Although glucomannan, a component of konjac, have been used for several clinical studies, there is few reports using konjac itself. This study examined the effects of the active consumption of konjac in patients with type 2 diabetes mellitus (T2DM). METHODS: The study included 26 Japanese patients with T2DM. Participants were recommended to take konjac at least once a day using free konjac products (various noodles, rice, and desserts) and plate konjac for 12 weeks. RESULTS: HbA1c and fasting plasma glucose levels significantly decreased from 8.3 ± 0.9% to 8.0 ± 0.8% and from 173.2 ± 44.4 to 152.8 ± 36.7 mg/dL, respectively. No significant changes were observed in body weight and insulin resistance indices, but the index for insulin secretion significantly increased. Serum high molecular weight adiponectin levels significantly increased. Plasma ghrelin, leptin and glucagon-like peptide-1 levels tended to decrease (p = 0.084), decrease (p = 0.057) and increase (p = 0.071), respectively. Actual konjac intake positively correlated with age (r = 0.61, p = 0.001). Body weight and HbA1c significantly decreased in patients aged ≥50 years than in those aged <50 years, and the changes significantly inversely correlated with age. CONCLUSION: Active consumption of konjac and konjac products seems to be a useful dietary therapy with multifaceted action for T2DM. Further studies with greater sample size and long-term are needed to confirm these findings.

Generation of thermostable Moloney murine leukemia virus reverse transcriptase variants using site saturation mutagenesis library and cell-free protein expression system.

We attempted to increase the thermostability of Moloney murine leukemia virus (MMLV) reverse transcriptase (RT). The eight-site saturation mutagenesis libraries corresponding to Ala70-Arg469 in the whole MMLV RT (Thr24-Leu671), in each of which 1 out of 50 amino acid residues was replaced with other amino acid residue, were constructed. Seven-hundred and sixty eight MMLV RT clones were expressed using a cell-free protein expression system, and their thermostabilities were assessed by the temperature of thermal treatment at which they retained cDNA synthesis activity. One clone D200C was selected as the most thermostable variant. The highest temperature of thermal treatment at which D200C exhibited cDNA synthesis activity was 57ºC, which was higher than for WT (53ºC). Our results suggest that a combination of site saturation mutagenesis library and cell-free protein expression system might be useful for generation of thermostable MMLV RT in a short period of time for expression and selection.