The protective effect of
Kangen-karyu extract and its mechanisms against
fructose-induced
metabolic syndrome have been investigated using a rat model. Male Wistar rats were fed a high
fructose (65%) diet or standard chow for one week, and for two subsequent weeks were treated with 50 or 100 mg kg(-1)
body weight/day
Kangen-karyu extract or vehicle. Serum
glucose,
glycosylated protein,
triglyceride (TG), total
cholesterol, and blood pressure levels of high-
fructose-fed rats were increased compared with those of normal rats. However,
Kangen-karyu extract ameliorated the high-
fructose-induced
metabolic syndrome including hyperglycaemia and hypertriglyceridaemia. In addition, the increase of hepatic TG content in rats given the high
fructose diet was significantly inhibited with the regulation of
sterol regulatory element-binding protein (SREBP)-1 expression by
Kangen-karyu extract. On the other hand,
peroxisome proliferator-activated receptor alpha and SREBP-2
protein levels were not affected by the feeding of the high
fructose diet or
Kangen-karyu extract. Moreover,
Kangen-karyu extract administration to high-
fructose-fed rats markedly reduced the
thiobarbituric acid-reactive substance levels in serum, hepatic homogenate, and mitochondria. Furthermore, it inhibited the increase of
cyclooxygenase (COX)-2 with the regulation of nuclear factorkappa B (
NF-kappaB) and bcl-2
proteins in the liver, suggesting that the protective potential of
Kangenkaryu extract against
metabolic syndrome would be attributed to the regulation of COX-2,
NF-kappaB, and bcl-2 signalling pathways. This study indicated that
Kangen-karyu extract significantly improved high-
fructose-induced
metabolic syndrome such as hyperglycaemia, hyperlipidaemia, and
hypertension through the reductions of TG and
cholesterol contents with the regulation of hepatic SREBP-1
protein and the
NF-kappaB signalling pathway.