The action of polyphenols and the various metabolites on glucose uptake has been investigated [32], [43] and [45]. Tsuda et al., found that polyphenol caffeic acid, but not chlorogenic acid, stimulated activation of AMPK and increased insulin-independent glucose uptake in healthy male rat skeletal muscle in vitro [45]. Neither component affected the phosphorylation status (Ser473) of Akt [45]. Ong et al., reported that intravenous administration of chlorogenic acid decreased fasting blood glucose in db/db mice subjected to an oral glucose tolerance test and that chlorogenic acid increased glucose transport in isolated soleus muscle [32].