Gut microbial composition of elderly women born in the Japanese longevity village Ogimi.

Ogimi is one of Japan's longevity villages and is located in Okinawa Prefecture. In this study, we focused on the elderly women living in the village, classified them into two groups based on whether or not they lived in Ogimi during the first 3 years of their lives, and compared the gut microbiota between the two groups. There were no differences in alpha and beta diversity; however, we found that the elderly women who lived in Ogimi during the first 3 years of their lives had a higher rate of Akkermansia muciniphila colonization in their guts.

Quantitative Analysis of Glycosylinositol Phosphoceramide and Phytoceramide 1-Phosphate in Vegetables.

Previously, we found an unidentified sphingolipid in cabbage, and determined it as phytoceramide 1-phosphate (PC1P). PC1P is found to be produced from glycosylinositol phosphoceramide (GIPC) by the action of phospholipase D (PLD) activity. Although GIPC is abundant sphingolipid, especially in cruciferous vegetables, amount of daily intake, digestibility and nutritional activity of GIPC are not well understood. Here, we investigated amounts of GIPC and PC1P in vegetables. GIPC was found in all vegetables examined (13 kinds) at levels 3-20 mg/100 g (wet weight). On the other hand, PC1P was present in limited vegetables which show higher GIPC-PLD activity, such as inner cabbage leaves (5.2 mg/100 g). Because PC1P is formed during homogenization by activated GIPC-PLD, level of PC1P in boiled cabbage leaves was very low. Although digestibility of GIPC is unknown at present, a portion of dietary GIPC is considered to be converted to PC1P during mastication by plant-derived GIPC-PLD activity in some vegetables.

Glycosylinositol phosphoceramide-specific phospholipase D activity catalyzes transphosphatidylation.

Glycosylinositol phosphoceramide (GIPC) is the most abundant sphingolipid in plants and fungi. Recently, we detected GIPC-specific phospholipase D (GIPC-PLD) activity in plants. Here, we found that GIPC-PLD activity in young cabbage leaves catalyzes transphosphatidylation. The available alcohol for this reaction is a primary alcohol with a chain length below C4. Neither secondary alcohol, tertiary alcohol, choline, serine nor glycerol serves as an acceptor for transphosphatidylation of GIPC-PLD. We also found that cabbage GIPC-PLD prefers GIPC containing two sugars. Neither inositol phosphoceramide, mannosylinositol phosphoceramide nor GIPC with three sugar chains served as substrate. GIPC-PLD will become a useful catalyst for modification of polar head group of sphingophospholipid.

[Hybrid liposomes as a drug carrier for the oral administration of insulin in diabetic rats].

It is known that hybrid liposomes composed of dimyristoylphosphatidylcholine (DMPC) and micellar surfactant (Tween 20) are effective for encapsulating drugs and for the treatment of meningeal gliomatosis in vivo without toxicity. In this study, we attempted to use these hybrid liposomes as a drug carrier system for the oral administration of insulin using diabetic model rats. The noteworthy aspects were as follows: (a) The hybrid liposomes of 90 mol% DMPC/10 mol% Tween 20 were stable and uniform for more than 4 weeks. (b) The blood glucose level of diabetic model rats decreased after the oral administration of hybrid liposomes including insulin. These results suggest that the oral administration of hybrid liposomes including insulin should be effective for the treatment of diabetes.

Enzymatic and hyperglycemia stability of chemically modified insulins with hydrophobic acyl groups.

The acylated insulins were synthesized by the reaction of insulin protected by p-methoxybenzoxy carbonyl azide at Gly-A1 site with N-hydroxysuccinimide ester of caproic acid or benzoic acid (Cap-insulin and Bz-insulin). The noteworthy aspects are as follows: (a) the acylated insulins were more stable to the decomposition by various digestive enzymes as compared with native insulin in vitro. (b) Animal experiments using normal rats in vivo revealed that the Bz-insulin had an effective hypoglycemia activity almost similar to that of native insulin.