Chinese prescription kangen-karyu ameliorates the development of diabetic hepatic damages via regulating oxidative stress and inflammation in the liver of db/db mice.

The prevention and treatment of diabetic complications are considered to be the most important for the general care of diabetic patients. We have been conducting pre-clinical animal experiments related to diabetes using kangen-karyu, a Chinese prescription, to examine its therapeutic potential. In the present study, we further studied the anti-diabetic mechanism of kangen-karyu, especially on the regulation of hyperglycemia-induced hepatic oxidative stress and inflammation in db/db mice. Kangen-karyu (100 or 200 mg/kg body weight/day, per os (p.o.) was administered every day for 18 weeks to db/db mice, and its effect was compared with vehicle-treated db/db and m/m mice. The administration of kangen-karyu decreased the elevated serum and hepatic glucose concentration in db/db mice. The elevated expressions of p22(phox) and Nox-4 proteins (reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits) were significantly decreased after kangen-karyu treatments. The oxidative stress-related markers in hepatic tissue (reactive oxygen species, reduced glutathione/oxidized glutathione ratio, and thiobarbituric acid-reactive substance) were also significantly ameliorated by the kangen-karyu treatments. The db/db mice exhibited the up-regulation of nuclear factor-κBp65, cyclooxygenase-2, and inducible nitric oxide synthase levels in the liver; however, kangen-karyu treatment significantly reduced those expressions. Taking these into consideration, our findings support the therapeutic evidence for kangen-karyu ameliorating the development of diabetic hepatic damages via regulating oxidative stress and inflammation.