Profiling age-related muscle weakness and wasting: neuromuscular junction transmission as a driver of age-related physical declineaursc20dev
Physiological changes that lead to skeletal muscle dysfunction and atrophy during aging are poorly understood and thus therapeutic interventions which
Effects of Prolonged Dietary Curcumin Exposure on Skeletal Muscle Biochemical and Functional Responses of Aged Male Ratsaursc20dev
Sarcopenia, an age-related condition involving the decline of muscle mass and function, affects 11-50% of those 80 years and older. The causes of sarcopenia are complex as the process of aging is characterized by several biological events. Skeletal muscle oxidative stress is one example and can result in disrupted cellular redox regulation and altered transcription factor activity. In this paper, the authors focus on characterizing the effects of curcumin, a compound shown to combat oxidative damage-inducing agents in aging skeletal muscle. As such, this study analyzed muscle mass and function in aged F344xBN rats exposed to long-term dietary curcumin. Rats were divided into three groups, one of which was provided a curcumin supplemented diet (CUR), the second consisting of rats given a modified amount of food to match the food consumption of CUR rats (PAIR), and a control group consuming a standard diet (CON). After four months of dietary supplementation, functional assessment of the rat plantaris muscle was assessed in situ. Contractile characteristics were measured isometrically at optimal length to determine maximum twitch and tetanic tension using the 1305A 3-in-1 Whole Animal System. The authors found that plantaris muscle mass and peak tetanic tension was significantly greater in CUR mice when compared to PAIR mice. Furthermore, both CON and CUR mice had significantly greater plantaris peak twitch tension than PAIR mice. In addition to this, molecular analysis showed that CUR mice exhibited greater levels of nuclear nrf2 and lower levels of oxidative damage markers when compared to PAIR mice. These differences in expression may mediate the increased peak twitch tension and peak tetanic tension seen in CUR mice, as oxidative stress can cause muscle contractile dysfunction and thus decreased force. In a complimentary study, CUR mice exhibited a greater peak twitch and specific tetanic tension response of the plantaris when administered curcumin via osmotic pumps. Taken together, these findings may help in elucidating the effectiveness of long-term curcumin supplementation in treating sarcopenia.