Accumulating evidence indicates that uncontrolled diabetes leads to the progression of
diabetic complications such as liver disorder. The present study was carried out to elucidate the protective role of
loganin extracted from Corni Fructus against hepatic oxidative stress caused by
type 2 diabetes.
Loganin (20 or 100mg/kg
body weight/day, p.o.) was administered every day for 8 weeks to db/db mice, and its effect was assessed on comparison with vehicle-treated db/db and m/m mice. The administration of
loganin led to a decrease in
glucose and elevation of
leptin in serum. The diabetic oxidative stress was attenuated by
loganin through inhibitions of
reactive oxygen species production and lipid peroxidation in the serum and liver. The expression of
proteins induced by oxidative stress was significantly up-regulated in the liver of diabetic db/db mice; however, the expressions of both Nox-4 and p22(
phox) were decreased significantly by
loganin administration.
Loganin showed a crucial effect in the
inflammation-activated signaling pathway through the regulation of NF-κB, COX-2, and iNOS. It was also found to regulate the anti-inflammatory factors Nrf-2 and HO-1 in hepatic tissue. Moreover, expression of MCP-1 was significantly down-regulated in the
loganin-treated db/db mice. Furthermore,
loganin administration showed a protective effect against apoptosis by the regulation of Bcl-2 and
cytochrome c. The present study demonstrated that the administration of
loganin isolated from Corni Fructus had a protective effect against hepatic oxidative stress under
type 2 diabetes through regulations of
protein expressions related to oxidative stress,
inflammation, and apoptosis.