Effects of Citrus depressa Hayata Fruit Extract on Thigh Muscles Mass and Composition in Subacute Stroke Patients: A Double-Blind, Randomized, Controlled Pilot Trial.

Objective: This pilot study evaluated the effects of Citrus depressa Hayata fruit extract (CFEx) on thigh muscle cross-sectional area (CSA) and composition in subacute stroke patients with hemiparesis who were undergoing rehabilitation. Design and Intervention: This double-blinded, placebo-controlled, randomized pilot trial included 40 subacute stroke patients with moderate-to-severe hemiparesis, and they were randomly assigned to receive CFEx or placebo supplements for 12 weeks. The thigh muscle CSA was measured by computed tomography as total muscle area defined by Hounsfield units (HU) values of -29 to 150 HU. The total muscle area was divided into muscle area with fat infiltration and normal muscle area to evaluate muscle composition (-29 to 29 and 30 to 150 HU, respectively). Results: At baseline, the total muscle area and normal muscle area in the paretic thigh were lower than those in the nonparetic thigh. The nonparetic normal muscle area was significantly higher in the CFEx group than in the placebo group at 12 weeks, whereas the total muscle area was not different. Conclusions: The thigh muscle CSA and composition in the paretic side have already deteriorated in patients with moderate-to-severe hemiparesis at the subacute stroke stage. CFEx supplementation during rehabilitation might improve the nonparetic thigh muscle composition in subacute stroke patients. Findings of this study are needed to be verified by a large-scale randomized trial since this study was a pilot study with a small sample size. Trial registration: UMIN Clinical Trial Registry (UMIN ID: UMIN000012902).

Effects of Glucose with Casein Peptide Supplementation on Post-Exercise Muscle Glycogen Resynthesis in C57BL/6J Mice.

Numerous studies have reported that post-exercise ingestion of carbohydrates with protein supplementation can enhance glycogen recovery. However, few reports have focused on the degrees of degradation of the ingested proteins due to post-exercise glycogen resynthesis. Accordingly, the aim of this study was to clarify the effects of differences in protein degradation on muscle glycogen recovery. Male seven-week-old C57BL/6J mice performed a single bout of 60-min treadmill running exercise and were then orally administered glucose (Glu; 1.5 mg/g body weight (BW)), glucose with casein peptide (Glu + Pep; 1.5 + 0.5 mg/g BW) or its constituent amino acid mixture (Glu + AA; 1.5 + 0.5 mg/g BW). At 120 min after supplementation, the soleus muscle glycogen content in the Glu and Glu + AA groups was significantly higher than that immediately after exercise; however, no such difference was observed in the Glu + Pep group. Blood substrate concentration and insulin signaling did not differ among the three groups. Furthermore, energy expenditure during the recovery period in the Glu + Pep group was significantly higher than that in the Glu and Glu + AA groups. These findings suggest that post-exercise co-ingestion of glucose and casein peptide might delay glycogen resynthesis, at least in part through increased energy expenditure caused by casein peptide ingestion.

Comparison between pre-exercise casein peptide and intact casein supplementation on glucose tolerance in mice fed a high-fat diet.

We hypothesized that along with exercise, casein peptide supplementation would have a higher impact on improving glucose tolerance than intact casein. Male 6-week-old ICR mice were provided a high-fat diet to induce obesity and glucose intolerance. The mice were randomly divided into 4 treatment groups: control (Con), endurance training (Tr), endurance training with intact casein supplementation (Cas+Tr), and endurance training with casein peptide supplementation (CP+Tr). The mice in each group were orally administrated water, intact casein, or casein peptide (1.0 mg/g body weight, every day), and then subjected to endurance training (15-25 m/min, 60 min, 5 times/week for 4 weeks) on a motor-driven treadmill 30 min after ingestion. Our results revealed that total intra-abdominal fat was significantly lower in CP+Tr than in Con (p < 0.05). Following an oral glucose tolerance test, the blood glucose area under the curve (AUC) was found to be significantly smaller for CP+Tr than for Con (p < 0.05). Moreover, in the soleus muscle, glucose transporter 4 (GLUT4) protein levels were significantly higher in CP+Tr than in Con (p < 0.01). However, intra-abdominal fat, blood glucose AUC, and GLUT4 protein content in the soleus muscle did not alter in Tr and Cas+Tr when compared with Con. These observations suggest that pre-exercise casein peptide supplementation has a higher effect on improving glucose tolerance than intact casein does in mice fed a high-fat diet.