Fermented ginseng protects streptozotocin-induced damage in rat pancreas by inhibiting nuclear factor-kappaB

In this study, we investigated the protective effects of fermented ginseng (FG) on hyperglycemia induced by streptozotocin (STZ) in Sprague Dawley rats. FG was administered orally at dose of 250 (FGL) or 500 mg/kg (FGH) for 20 days starting one week before STZ injection. FG restored the plasma insulin levels by 266% and 334% in FGL and FGH, respectively, and resulting in reduction of plasma glucose concentration. Histological observation indicated that STZ-induced destruction of pancreatic islets was protected by FG. Consistent with this observation, FG reduced protein and mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as determined by Western blotting and RT-PCR, respectively. The molecular mechanism of FG's inhibition of iNOS and COX-2 gene expressions appeared to involve the inhibition of nuclear factor-kappaB (NF-kappaB) activation via prevention of inhibitor kappaB (IkappaB) phosphorylation and degradation. The cytoprotective effects of FG were also mediated through suppression of extracelluar signal-regulated kinase (ERK) and c-JUN N-terminal kinase (JNK) pathways. Collectively, these results suggest that FG might be used to preserve functional beta-cell mass.