A meroterpene and four flavonoids were isolated from the seeds of Psoralea corylifolia as antioxidative components. Their structures were elucidated by spectral data and identified as bakuchiol (1), bavachinin (2), bavachin (3), isobavachin (4) and isobavachalcone (5). In particular, meroterpene 1 and flavonoids 4 and 5 showed broad antioxidative activities in rat liver microsomes and mitochondria. They inhibited NADPH-, ascorbate-, t-BuOOH- and CCl(4)-induced lipid peroxidation in microsomes. They also prevented NADH-dependent and ascorbate-induced mitochondrial lipid peroxidation. Bakuchiol (1) was the most potent antioxidant in microsomes and the inhibition of oxygen consumption induced by lipid peroxidation was time-dependent. Furthermore, bakuchiol (1) protected human red blood cells against oxidative haemolysis. These phenolic compounds in P. corylifolia were shown to be effective in protecting biological membranes against various oxidative stresses.

This study was performed to examine the effect of dietary polyphenols on fecal secondary bile acids, such as deoxycholic acid and lithocholic acid, the risk factors of colon cancer, in rats fed a high-fat diet. In experiment 1, rats were fed a 30% beef tallow diet containing 0.5% polyphenols for 3 weeks. Dietary curcumin and caffeic acid significantly reduced the fecal concentration of deoxycholic acid. Dietary caffeic acid, catechin, rutin, and ellagic acid significantly reduced fecal lithocholic acid. Fecal hyodeoxycholic acid, a metabolite of lithocholic acid, was markedly lowered by dietary curcumin, caffeic acid, catechin, and rutin. In experiment 2, rats were fed a 30 or 5% beef tallow diet with or without the addition of 0.5% curcumin. In the rats without receiving curcumin, the fecal level of deoxycholic acid was significantly higher in the high-fat diet group than in the low-fat diet group. Fecal deoxycholic acid was significantly reduced by dietary curcumin in the high-fat diets but not in the low-fat diets. The results suggest novel effects of some polyphenols favorable for colon health by reducing secondary bile acids in animals fed a high-fat diet.

Bakuchiol, a meroterpene isolated from Psoralea corylifolia, prevented mitochondrial lipid peroxidation. Inhibition of oxygen consumption originating in lipid peroxidation was time-dependent. Bakuchiol protected mitochondrial respiratory enzyme activities against both NADPH-dependent and dihydroxyfumarate-induced peroxidation injury. Bakuchiol was shown to be effective to protect mitochondrial functions against oxidative stress.

No abstract

No abstract

This study demonstrated that 0.5% dietary rutin, ellagic acid, or curcumin markedly increased cecal succinate levels in rats fed a high-fat diet, whereas catechin, caffeic acid, and quercetin did not. Other organic acids were modestly or hardly affected by polyphenols. To clarify the effects of succinate levels increased by polyphenols, this study examined the effects of succinate on the growth and proliferation of colon cancer cells and angiogenesis. The growth and proliferation of HT29 human colon cancer cells and angiogenesis in an ex vivo model were significantly inhibited by succinate at a dose close to that in the cecum of rats fed polyphenols. Furthermore, succinate inhibited the migration of human umbilical vein endothelial cells. These findings suggest that the consumption of some polyphenols affects the health and diseases of the large intestine by elevating succinate.

The present study investigated the effects of the dietary addition of the protease preparations derived from on the colonic luminal environment. Rats were fed a 30% beef tallow diet with or without the protease preparations, including Amano protease (protease A 'Amano SD', neutral proteases from spp.) or orientase (orientase AY, acid proteases from ) at the dose of 0.2% for 3 weeks. Cecal was significantly elevated in the dietary Amano protease group (194-fold, P<0.05), but not in the orientase group. was elevated in the two groups (P<0.05). Cecal -butyrate, propionate and lactate were higher in the Amano protease and orientase groups compared with the controls (P<0.05). Fecal immunoglobulin A and mucins were elevated in the Amano protease group (P<0.05). These results suggest the potential effect of the consumption of -derived protease preparations that are favorable for the colonic luminal environment in rats fed a high-fat diet.

Root of burdock contains high amounts of dietary fibers and polyphenols. To improve the functional properties, the root was fermented with Aspergillus awamori. Effect of the fermented burdock on alloxan-induced mouse diabetes was examined. A diet containing the 5% fermented burdock powers was prepared to examine effect of the burdock diet on alloxan-induced mouse diabetes. Mice fed the burdock diet and the control diet for 14 weeks. Then, alloxan (200 mg/kg of body weight) was administrated to each mouse. After 5 days from the administration, blood glucose assay and glucose tolerance test were carried out. Incidence of hyperglycemia decreased and the glucose metabolism was improved when mice fed the burdock diet. Insulin, C-peptide, biomarkers of oxidative stress in plasma and apoptosis in pancreas were examined and compared to those obtained from mice fed the control diet. It is deduced that alloxan-induced diabetes is caused to lower insulin concentration. The fermented-burdock diet improves the diabetes and prevents apoptosis in the pancreas.