RESUMO
Objective: Antrodia cinnamomea (AC), a medicinal mushroom indigenous to Taiwan, exerts various pharmacologic activities. This study compared and evaluated the hypoglycemic effect of treatment with electroacupuncture (EA) combined with AC in steroid-induced insulin-resistant (SIIR) rats. Materials and Methods: Rats were divided into saline, EA, AC, AC+EA, and rosiglitazone (TZD) groups. Plasma-glucose levels were measured in serial blood samples and compared before and after treatment in each group. The levels of signaling proteins-glucose transporter 4, (GLUT4), phosphoinositide 3-kinase (PI3-K), and 5' adenosine monophosphate-activated protein kinase (AMPK)-were analyzed by Western blotting to explore their mechanisms of action. Results: The AC+EA group had reduced plasma-glucose levels at 30 and 60 minutes in SIIR rats, compared to normal rats, and this was better than the EA, AC, and TZD groups at 60 minutes. Furthermore, the signaling protein (GLUT4, PI3-K, and AMPK) levels were increased significantly. Conclusions: These findings showed improved hypoglycemic activity and insulin resistance after EA combined with AC treatment. Therefore, the combined therapy might be a more-effective method than the individual therapies that elevates the expression of the signal proteins, as observed in this study.
RESUMO
BACKGROUND: Previous studies have reported that electroacupuncture (EA) induces a glucose-lowering effect by improving insulin resistance (IR) and reduces plasma free fatty acid (FFA) levels in rats with steroid-induced insulin resistance (SIIR). In addition, EA can activate cholinergic nerves and stimulate endogenous opioid peptides to lower plasma glucose in streptozotocin-induced hyperglycemic rats. The aim of this study was to investigate the glucose-lowering effects of 15 Hz EA at bilateral ST36 in combination with acarbose (ACA). We hypothesized that EA combined with ACA would produce a stronger glucose-lowering effect than ACA alone. METHODS: In this study, normal Wistar rats and SIIR rats were randomly divided into two groups: ACA and ACA + EA. To explore the potential mechanisms underlying the glucose-lowering effect, plasma FFA/insulin and insulin transduction signal pathway proteins were assayed. RESULTS: Combined ACA + EA treatment had a greater glucose-lowering effect than ACA alone in normal Wistar rats (-45% ± 3% vs -19% ± 3%, p < 0.001) and SIIR model rats (-43% ± 2% vs -16% ± 6%, p < 0.001). A significant reduction in plasma FFA levels, improvement in homeostatic model assessment of IR (HOMA-IR) index (-48.9% ± 4.0%, p < 0.001) and insulin sensitivity index (102% ± 16.9%, p < 0.001), and significant increases in insulin receptor substrate 1, glucose transporter 4, and peroxisome proliferator-activated receptor γ protein expressions in skeletal muscle, were also observed in the ACA + EA group of SIIR rats. CONCLUSION: Combined EA and ACA therapy had a greater glucose-lowering effect than ACA monotherapy; this combined therapy could be more effective at improving IR in SIIR rats, which may be related to a reduction in plasma FFA levels and an elevation of insulin signaling proteins. Whether this combined therapy has an effect in type 2 diabetes mellitus (T2DM) patients still needs to be explored.