Toshiaki Takano

Transepithelial transport of the bioactive tripeptide, Val-Pro-Pro, in human intestinal Caco-2 cell monolayers.

Some of the food-derived tripeptides with angiotensin converting enzyme (ACE)-inhibitory activity have been reported to be hypotensive after being orally administered. The mechanism for the intestinal transport of these tripeptides was studied by using monolayer- cultured human intestinal Caco-2 cells which express many enterocyte-like functions including the peptide transporter(PepT1)-mediated transport system. Val-Pro-Pro, an ACE-inhibitory peptide from fermented milk, was used as a model tripeptide. A significant amount of intact Val-Pro-Pro was transported across the Caco-2 cell monolayer. This transport was hardly inhibited by a competitive substrate for PepT1. Since no intact Val-Pro-Pro was detected in the cells, Val-Pro-Pro apically taken by Caco-2 cells via PepT1 was likely to have been quickly hydrolyzed by intracellular peptidases, producing free Val and Pro. These findings suggest that PepT1-mediated transport was not involved in the transepithelial transport of intact Val-Pro-Pro. Paracellular diffusion is suggested to have been the main mechanism for the transport of intact Val-Pro-Pro across the Caco-2 cell monolayer.

Producibility and digestibility of antihypertensive beta-casein tripeptides, Val-Pro-Pro and Ile-Pro-Pro, in the gastrointestinal tract: analyses using an in vitro model of mammalian gastrointestinal digestion.

Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) are antihypertensive tripeptides isolated from milk fermented with Lactobacillus helveticus and inhibit angiotensin-converting enzyme (ACE). We investigated whether these peptides were generated from beta-casein by digestive enzymes and whether they were resistant to enzymatic hydrolysis, using an in vitro model. VPP and IPP were not generated from beta-casein by gastrointestinal enzymes; instead, a number of longer peptides including VPP and IPP sequences were detected. The fermentation step would therefore be necessary to produce these antihypertensive tripeptides. VPP and IPP themselves were hardly digested by digestive enzymes, suggesting that orally administered VPP and IPP remain intact in the intestine, retaining their activity until adsorption. The present study also demonstrated that various functional peptide sequences in beta-casein were resistant to gastrointestinal enzymes. There may be a strong correlation between the resistance of peptides to gastrointestinal digestion and their real physiological effects after oral administration.

Oral intake of Lactobacillus helveticus-fermented milk whey decreased transepidermal water loss and prevented the onset of sodium dodecylsulfate-induced dermatitis in mice.

We investigated the effects of oral intake of Lactobacillus helveticus-fermented milk whey on the intact and sodium dodecylsulfate (SDS)-exposed skin of Hos:HR-1 hairless mice. The mice were allowed to drink 10% L. helveticus-fermented milk whey in distilled water ad libitum for 5 weeks. SDS solution was topically applied to the dorsal skin at 4 weeks, leading to the development of dermatitis. The skin moisture content, transepidermal water loss, and sizes of the dermatitis areas were periodically measured. Compared with oral intake of water alone, oral intake of water containing L. helveticus-fermented milk whey for 4 weeks significantly lowered transepidermal water loss from intact skin, significantly reduced in size the areas of early SDS-induced dermatitis, and ameliorated both the SDS-induced decrease in moisture content and the increase in transepidermal water loss. These results suggest that oral intake of L. helveticus-fermented milk whey might be effective in promoting the epidermal barrier function and in preventing the onset of dermatitis.

Cell transfer printing from patterned poly(ethylene glycol)-oleyl surfaces to biological hydrogels for rapid and efficient cell micropatterning.

Cell transfer printing from patterned poly(ethylene glycol)‐oleyl surfaces onto biological hydrogel sheets is investigated herein, as a new cell stamping method for both cell microarray and tissue engineering. By overlaying a hydrogel sheet on the cells immobilized on the poly(ethylene glycol)‐oleyl surface and successively peeling it off, the immobilized cells were transferred onto a hydrogel sheet because the adhesive interaction between the cells and the hydrogel was stronger than that between the cells and the poly(ethylene glycol)‐oleyl surface. Four types of human cell could be efficiently transferred onto a rigid collagen sheet. The transfer printing ratios, for all cells, were above 80% and achieved within 90 min. A cell microarray was successfully prepared on a collagen gel sheet using the present stamping method. We have also demonstrated that the transferred pattern of endothelial cells is transformed to the patterned tube‐like structure on the reconstituted basement membrane matrix. Finally, the patterns of two types of endothelial cell are shown to be easily prepared on the matrix, and the desired tube‐like structures, including the orderly pattern of the two different cells, were formed spontaneously. Thus, the present poly(ethylene glycol)‐oleyl coated substrates are useful for rapid and efficient cell stamping, in the preparation of multi‐cellular pattern on extracellular matrices. Biotechnol. Bioeng. 2012;109: 244–251.

The Japanese Nutritional Health Beverage Market

The beverage market in postwar Japan started with carbonated and fruit-flavored drinks, following the trend of Western countries. More recently, several innovative beverage products have been developed, including fermented milk-flavored drinks, canned coffee, and teas. Today, Japan is recognized as leading the market in these categories. Nutritional/health beverages started with drinks that offered nourishment and tonic properties and/or nutrient supplements. In 1991, legislation was passed, Foods for Specified Health Uses (FOSHU), that approves labels that make health claims. As a result, many products have appeared and the market is continuing to develop rapidly and uniquely. The latest trends in the nutritional/health beverage market and the present situation of regulation on health claims are summarized in this chapter, with a focus on the Foods with Health Claims system, which started in 2001.