Our group has progressively reported on the impact of bioactive compounds found in rooibos (Aspalathus linearis) and their capacity to modulate
glucose homeostasis to improve metabolic function in experimental models of
type 2 diabetes. In the current study, we investigated how the dietary
flavone,
orientin, modulates the essential genes involved in energy regulation to enhance substrate metabolism. We used a well-established hepatic
insulin resistance model of exposing C3A liver cells to a high concentration of
palmitate (0.75 mM) for 16 hrs. These
insulin-resistant liver cells were treated with
orientin (10 µM) for 3 h to assess the
therapeutic effect of
orientin. In addition to assessing the rate of metabolic activity, end point measurements assessed include the uptake or utilization of
glucose and
palmitate, as well as the expression of genes involved in
insulin signaling and regulating cellular energy homeostasis. Our results showed that
orientin effectively improved metabolic activity, mainly by maintaining substrate utilization which was marked by enhanced
glucose and
palmitate uptake by liver cells subjected to
insulin resistance. Interestingly, these effects can be explained by the improvement in the expression of genes involved in
glucose transport (Glut2),
insulin signaling (Irs1 and Pi3k), and energy regulation (Ampk and Cpt1). These preliminary findings lay an important foundation for future research to determine the bioactive properties of
orientin against
dyslipidemia or
insulin resistance in reliable and well-established models of
type 2 diabetes.