Toshiharu Gomyo

Improvements in Seasonal Allergic Disease with Lactobacillus plantarum No. 14

We conducted two randomized, placebo-controlled, double-blind studies of Lactobacillus plantarum No. 14 (LP14) in female students with seasonal allergic diseases. We also examined the mitogenic activity and cytokine inducibility of LP14 using Peyer’s patch cells and mesenteric lymph node cells of swine. For subjects who took 8.7×108 of LP14, a significant improvement in ocular symptom-medication score was observed. In the placebo group, the T helper type 1 (Th1)/T helper type 2 (Th2) ratio tended to decrease after a 6-week intake period, while in the LP14 group, the percentage of Th1 cells significantly increased. Post-intake eosinophil counts significantly increased in comparison to those at intake cessation in the placebo group, but it appeared to be suppressed in the LP14 group. There were no changes in fecal microflora. LP14 strongly induced the gene expression of Th1-type cytokines. This study indicates the clinical effects of LP14 on seasonal allergic diseases.

Low-dose arachidonic acid intake increases erythrocytes and plasma arachidonic acid in young women

Arachidonic acid (ARA) is considered to be a minor contributor to the diet. Previous reports regarding the effect of ARA supplementation on the composition of long-chain polyunsaturated fatty acids (LCPUFA) in the blood of humans are extremely limited. In the present study, we conducted a crossover double-blind, placebo-control study. Twenty-three young Japanese women consumed one capsule containing triacylglycerol enriched with 80 mg ARA, equivalent to the amount in one egg, daily for 3 weeks. Blood samples were drawn before and after treatment periods, and the compositions of the LCPUFA in blood lipid fractions were measured. The supplementation of ARA increased the composition of ARA, but did not decrease the composition of n-3LCPUFA in erythrocyte phospholipids and plasma phospholipids, esterified cholesterol, and triacylglycerol. We found that dietary ARA increased the ARA level in all lipid fractions of the blood, even at a very low dose.

Kinetic Analysis of the Inhibition by Melanoidin of Trypsin

The inhibition by melanoidin of trypsin was investigated in a kinetic approach. Melanoidin was prepared by the Maillard reaction between D-glucose and glycine, and BANA was used as a substrate. The inhibition was found to follow a non-competitive mode with a Ki of 5.8% and to be exerted through an electrostatic interaction between melanoidin and trypsin. Approximately 20% of the activity of trypsin survived even at a greatly increased concentration of melanoidin. The inhibiting mechanism of melanoidin might be due to an allosteric effect, which was probably different from a proteinaceous inhibitor such as ovoinhibitor diminishing trypsin-activity completely. The melanoidin molecule was thought to trap a great number of trypsin molecules, binding them and reducing their activity.

The gastrointestinal transit tolerance of Lactobacillus plantarum strain No. 14 depended on the carbon source.

This study aimed to assess variations in the human gastrointestinal transit tolerance of Lactobacillus plantarum strain No. 14 after culture with glucose and with fructose. Transit tolerance was determined at 37 °C against simulated gastric juices at pH values of 2.5, 3.0, and 3.5, and against simulated small intestinal juices containing 0%, 0.2%, or 0.4% oxgall. The simulated gastrointestinal transit tolerance of Lactobacillus plantarum strain No. 14 varied with the carbon source. Hence we compared the amounts of exopolysaccharide from Lactobacillus plantarum strain No. 14 cultured in various carbon sources. The exopolysaccharide levels were 146.5±8.1 mg/l (culture) with glucose, and 20.1±17.0 mg/l (culture) with fructose. When exopolysaccharide was removed by centrifugation, the simulated gastric tolerance of Lactobacillus plantarum strain No. 14 cultured with glucose decreased markedly, but that with fructoce did not decrease. These results suggest that the gastrointestinal transit tolerance of Lactobacillus plantarum strain No. 14 is related to exopolysaccharide contents.

Inhibiting effect of browned processed foods on trypsin

Inhibition of proteases was examined in browned foods including soy pastes, soy sauces, fish sauce, sauces, teas, coffees, and others in association with melanoidin, a Maillard product, which had been found to be a potent inhibitor of trypsin. Most of the foods were effective in restraining trypsin activity based on hydrolysis of N-α-benzoyl-DL-arginine-p-nitroanilide, while being ineffective on chymotrypsin except for black tea and cola. Especially, teas were noted for their strong inhibitory effect on trypsin. The color intensity of the foods in terms of optical density at 400 nm appeared not to correlate with the extent of inhibition except for soy sauces.

A Tentative Measurement of Brown Pigments in Various Processed Foods.

A tentative method for measuring brown pigment in food was proposed and applied to 25 items of commercial browned foods. The principle was based on the assumption that any brown pigment with general absorption in the visible wave-length spectrum is quantitatively equivalent to melanoidin prepared from a model system of the Maillard reaction. The spectral curve for general absorption was represented by the equation dE/dλ=-kE (E, absorbance; λ = wave length; k = constant > 0), of which the value k w as found to correlate with the molecular weight and the molar extinction coefficient and to serve as an empirical parameter for the measurement of brown substances in different foods.