Effect of combination of chlorella intake and aerobic exercise training on glycemic control in type 2 diabetic rats

Chlorella is a type of unicellular green algae that contains various nutrients. Habitual exercise and chlorella treatment can improve insulin resistance in obese or diabetic animal models. However, the additive effects of combined chlorella intake and aerobic exercise training remain unclear. The aim of this study was to investigate whether a combination of chlorella intake and aerobic exercise training would produce greater effects on improving glycemic control in rats with type 2 diabetes.

Twenty-wk-old male rats with type 2 diabetes (Otsuka Long-Evans Tokushima Fatty [OLETF] rats) were randomly divided into four groups: sedentary control, aerobic exercise training (treadmill running for 1 h, 25m/min, 5 d/wk), chlorella intake (0.5% chlorella powder in normal diet), or combination of aerobic exercise training and chlorella intake for 8 wk (n = 7 per group).

Chlorella intake and aerobic exercise training significantly decreased fasting blood glucose, insulin levels, and total glucose area under the curve during the oral glucose tolerance test and increased the insulin sensitivity index concomitant with muscle phosphatidylinositol-3 kinase (PI3K) activity, protein kinase B (Akt) phosphorylation, and glucose transporter 4 (GLUT4) translocation levels. Furthermore, a combination of chlorella intake and aerobic exercise training significantly further improved these effects compared with aerobic exercise training or chlorella intake alone.

These results suggested that chlorella intake combined with aerobic exercise training had more pronounced effects on the improvement of glycemic control via further activation of muscle PI3K/Akt/GLUT4 signaling in rats with type 2 diabetes.