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Diabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia. Although the clear mechanisms of DM and insulin resistance are still to be cleared, it has been well documented that reactive oxygen species (ROS) play a pivotal role in DM and multiple types of insulin resistance. For the past few years, natural substances have been shown to have the potential to treatment DM. Attention has been especially focused on plants rich in triterpenoids, which generally show antioxidant and antiglycation effect. In our previous studies, it was shown that oleanolic acid (OA), a natural triterpenoid and an aglycone of many saponins, is a potent antioxidant acting as not only a free radical-scavenger through direct chemical reactions but also as a biological molecule, which may enhance the antioxidant defenses. The present study aimed to investigate the potential antidiabetic effect of OA. Oleanolic acid showed a significant blood glucose-lowering and weight-losing effect in diabetic animals induced by streptozotocin (STZ). In the insulin resistant model, it was also shown that OA may promote insulin signal transduction and inhibit oxidative stress-induced hepatic insulin resistance and gluconeogenesis, in which process the phosphorylation of ERK and the protective effect on mitochondrial function may be involved. These findings may significantly better the understanding of the pharmacological actions of OA and advance therapeutic approaches to DM. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Aging is accompanied by a marked decline in muscle strength and ability to maintain steady submaximal force. Studies have shown that exercise programs can improve age-related regression of hand function in elderly individuals. The purpose of this study was to train elderly subjects to perform skilled finger movements and to evaluate the changes in hand function involving skillful use of finger pinch.Methods: Grip strength, maximum pinch force (MPF), steadiness of pinch force at 5%, 10%, and 20% MPF, M wave, and Hoffman (H) reflex were measured. Fourteen elderly subjects were trained with skilled finger movements, and their performance involving finger pinch was measured.Results: Compared with untrained elderly subjects, the trained older adults significantly (p <.05) improved their ability to control submaximal pinch force, to maintain a steady hand posture, and to relocate a small object quickly with finger grip. The amplitude of H reflex increased significantly for the trained group.Conclusions: Skilled finger movement training improves the ability to control submaximal pinch force, hand steadiness, and manual speed in elderly subjects; these improvements may be due to training-induced adaptations in the central and peripheral nervous systems. [ABSTRACT FROM AUTHOR]