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SummaryAlthough hesperidin lowers serum total cholesterol (TC) or triglyceride (TG) in animal models, its effect in humans remains unclear. Using a soluble hesperidin derivative, glucosyl hesperidin (G-hesperidin), as a hesperidin source, we examined the efficacy on hyperlipidemic subjects. G-Hesperidin was administered to the subjects at 100 or 500mg/d for 6wk. The percentage of subjects who had a change in serum cholesterol levels was less than 20%. However, 45-55% of the total subjects showed a reduction in serum TG level. The subjects were classified into normal (TC<230mg/dL, TG<150mg/dL), high-TC (TC>230mg/dL, TG<150mg/dL) and high-TG (TG>150mg/dL) types. While serum cho lesterol levels scarcely changed in any phenotype, TG level was significantly reduced by administration in the high-TG type. In this phenotype, serum apolipoprotein (apo) C-II and E levels decreased by the administration, but non-apo B. G-Hesperidin also raised low-den sity lipoprotein (LDL)-cholesterollapo B in the high-TG type. These results indicate that G hesperidin preferentially lowers serum TG in hypertriglyceridemic subjects and that this effect is possibly caused by the facilitation of catabolism of TG-rich lipoproteins and may contribute to the reduction of small dense LDL.

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SummaryOur previous study has shown that a soluble hesperidin derivative, glucosyl hesperidin (G-hesperidin), preferentially lowers serum triglyceride (TG) level in hypertriglyceridemic subjects through the improvement of very low-density lipoprotein (VLDL) metabolic abnormality. G-Hesperidin has also been found to decrease an elevated serum apolipoprotein B (apo B) level in the hypertriglyceridemic subjects, suggesting a possibility that this compound suppresses excess VLDL secretion in the liver. In the present study, to gain a better understanding of possible mechanisms by which G-hesperidin lowers serum TG, we examined whether this derivative affects apo B secretion from HepG2 human hepatoma cells, a model of hepatic VLDL secretion. As a result, G-hesperidin significantly reduced apo B secretion from the oleate-stimulated HepG2 cells. Furthermore, G-hesperidin significantly suppressed apo B secretion only in the oleate-stimulated cells and failed to act on the cells incubated without oleate. In the oleate-stimulated cells, G-hesperidin significantly decreased cellular cholesteryl ester (CE), although it had no effect on cellular TG or free cholesterol amounts. Moreover, the oleate-stimulated cells had a decrease in cellular apo B amounts by G-hesperidin exposure. These findings indicate that G-hesperidin downregulates the assembly of apo B-containing lipoproteins via the reduction of CE synthesis augmented with oleate and results in suppressing excess apo B secretion from the cells. This effect is speculated to be associated with the improvement of VLDL metabolic abnormality in hypertriglyceridemic subjects and considered as a mechanism of lowering serum TG. Key Words glucosyl hesperidin, very low-density lipoprotein, apolipoprotein B, cholesteryl ester, HepG2 cells Hesperidin, a citrus flavonoid, is well known to decrease capillary fragility and permeability ( 1 ). This compound has also been reported to have various physiological activities including antioxidant effect ( 1 ), antihypertensive effect ( 2 ) and antiallergic effect ( 3 ). Therefore, hesperidin has attracted attention as a multifunctional food ingredient. However, the use of this flavonoid in the field of foods has been limited because of its low water solubility.To solve this problem, Hijiya and Miyake have synthesized a soluble derivative of hesperidin, glucosyl hesperidin (G-hesperidin), by regioselective transglycosylation with cyclodextrin glucanotransferase from Bacillus stearothermophilus (Fig. 1) ( 4 ). G-Hesperidin is very soluble in water, and its solubility is about 10,000 times greater than that of conventional hesperidin ( 4 ). Moreover, it has been verified that this derivative releases hesperidin through hydrolysis by brush border ␣ -glucosidases ( 4 , 5 ). Our recent studies have shown that Ghesperidin as well as hesperidin exhibits such physiological activities as decrease of serum lipid peroxide level in hyperlipidemic mice ( 6 ), antihypertensive effect on spontaneously hypertensive rats ( 7 , 8 ) and suppression of passive ...

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The mouse intestinal neuroendocrine tumor cell line STC-1 secretes cholecystokinin (CCK) and other hormones. We investigated the role of Ca2+, calmodulin (CaM), and protein kinase C (PKC) in the regulation of CCK release from STC-1 cells. Phorbol 12-myristate 13-acetate (TPA) significantly stimulated CCK release. Staurosporine significantly inhibited CCK release from STC-1 cells stimulated by TPA in a dose-dependent manner. The absence of extracellular calcium completely inhibited CCK release from TPA-stimulated STC-1 cells. Neurotensin did not stimulate CCK release from these cells. W-7, a CaM antagonist, reduced CCK release from STC-1 cells stimulated by bombesin in a dose-dependent manner. These findings suggest that CaM and PKC play an important role in the regulation of CCK release from STC-1 cells stimulated by bombesin.

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