New records of potent in-vitro antidiabetic properties of Dalbergia tonkinensis heartwood and the bioactivity-guided isolation of active compounds

[[abstract]]Alpha-glucosidase inhibitory activity has been commonly used for the evaluation of antidiabetic property in vitro. The aim of this study is to investigate and characterize Dalbergia tonkinensis as a potential source of antidiabetic compounds. The screening of the active parts used, such as trunk bark, heartwood, and the leaves of Dalbergia tonkinensis indicated that all these extracted parts used with methanol demonstrated potent α-glucosidase inhibitory activity. The in vitro antidiabetic property of Dalbergia tonkinensis was notably recorded for the first time and showed activity (EC50 = 0.17–0.78 mg/mL) comparable to those of reported potent herbal extracts (EC50 = 0.25–4.0 mg/mL) and higher activity than that of acarbose, a commercial antidiabetic drug (EC50 = 1.21 mg/mL). The stability tests revealed that the heartwood of Dalbergia tonkinensis extract (HDT) possesses high pH stability with relative activity in the range of 80–98%. Further bioassay-guided purification led to the isolation of 2 active compounds identified as sativanone and formononetin from the ethyl acetate fraction and water fraction of HDT, respectively. These α-glucosidase inhibitors (aGIs) show promising inhibition against various types of α-glucosidases. Remarkably, these inhibitors were determined as new mammalian aGIs, showing good effect on rat α-glucosidase. The results suggest that Dalbergia tonkinensis is a potent source of aGIs and suggest promise in being developed as functional food with antidiabetic efficacy. The results of this study also enrich our knowledge concerning current biological activity and constituents of Dalbergia tonkinensis species.[[sponsorship]]科技部[[notice]]補正完

Designing for Diabetes Decision Support Systems with Fluid Contextual Reasoning

Type 1 diabetes is a potentially life-threatening chronic condition that requires frequent interactions with diverse data to inform treatment decisions. While mobile technolo- gies such as blood glucose meters have long been an essen- tial part of this process, designing interfaces that explicitly support decision-making remains challenging. Dual-process models are a common approach to understanding such cog- nitive tasks. However, evidence from the first of two stud- ies we present suggests that in demanding and complex situations, some individuals approach disease management in distinctive ways that do not seem to fit well within existing models. This finding motivated, and helped frame our second study, a survey (n=192) to investigate these behaviors in more detail. On the basis of the resulting analysis, we posit Fluid Contextual Reasoning to explain how some people with diabetes respond to particular situations, and discuss how an extended framework might help inform the design of user interfaces for diabetes management

The Mediterranean coral Cladocora caespitosa; a proxy for past climate fluctuations?

Sclerochronology was applied to recent, Holocene and Pleistocene samples of Cladocora caespitosa. Late Pliocene samples were recrystallised and thus unsuitable for sclerochronology. Quaternary samples showed a clear, alternating banding pattern as in the living coral, confirming a marked seasonality of past climate. The computed mean annual growth rates ranged from 2.1 to 6.9 mm year(-1) , with highest growth rates during the warmer phase (isotope stage 5e) of the first climate cycle. It is hypothesised that the largest fossil banks of C. caespitosa grew in a coastal environment with considerable alluvial inputs and warmer temperatures than today. (C) 2003 Elsevier B.V. All rights reserved