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Periodontal disease is related to aging, smoking habits, diabetes mellitus, and systemic inflammation. However, there remains limited evidence about causality from intervention studies. An effective diet for prevention of periodontal disease has not been well established. The current study was an intervention study examining the effects of a high-fiber, low-fat diet on periodontal disease markers in high-risk subjects. Forty-seven volunteers were interviewed for recruitment into the study. Twenty-one volunteers with a body mass index of at least 25.0 kg/m(2) or with impaired glucose tolerance were enrolled in the study. After a 2- to 3-week run-in period, subjects were provided with a test meal consisting of high fiber and low fat (30 kcal/kg of ideal body weight) 3 times a day for 8 weeks and followed by a regular diet for 24 weeks. Four hundred twenty-five teeth from 17 subjects were analyzed. Periodontal disease markers assessed as probing depth (2.28 vs 2.21 vs 2.13 mm; P < .0001), clinical attachment loss (6.11 vs 6.06 vs 5.98 mm; P < .0001), and bleeding on probing (16.2 vs 13.2 vs 14.6 %; P = .005) showed significant reductions after the test-meal period, and these improvements persisted until the follow-up period. Body weight (P < .0001), HbA1c (P < .0001), and high-sensitivity C-reactive protein (P = .038) levels showed improvement after the test-meal period; they returned to baseline levels after the follow-up period. In conclusion, treatment with a high-fiber, low-fat diet for 8 weeks effectively improved periodontal disease markers as well as metabolic profiles, at least in part, by effects other than the reduction of total energy intake.

必須脂肪酸のリノール酸は, 培養メラノーマ細胞のメラニン生成を抑制する作用をもつ。メラニン生成酵素であるチロシナーゼの活性はリノール酸により抑制された。しかしながら, チロシナーゼmRNA量はほとんど変化せず, リノール酸のメラニン生成抑制作用はチロシナーゼ遺伝子転写後の調節によると考えられた。さらに, リノール酸はチロシナーゼの分解を促進することが明らかとなり, その結果としてメラニンの生成を抑制していることが示唆された。また, リノール酸はリポソーム化することによって水溶性製剤中でも安定に存在し, 経時的に角層下へ浸透することが確認された。リポソーム化リノール酸配合製剤を用いて肝斑を対象とした使用試験を実施したところ, 高い有用率が認められた。リポソーム化リノール酸は皮膚美白剤として有用であることが示唆された。

Since the liposomal formulation of linoleic acid (LA) exhibited an enhanced skin-whitening effect, the influence of liposomalization on the cutaneous absorption of LA was examined using a three-dimensional (3D) reconstructed skin model. Liposome entrapped [(14)C]-LA was applied on the skin model, and the permeation of LA through the skin was monitored. The permeation rate of LA in the liposomal formulation was found to be lower than that in the conventional formulation without liposomes, suggesting the increased retention time of LA in the skin by the liposomal formulation. Next, to investigate the dependence of the LA permeation on melanocyte conditions and intactness of the reconstructed skin model, the effect of UV irradiation on LA permeation was examined. Low-dose UVB irradiation (0.03 J/cm(2) for 3 times), which activated melanocytes in the skin, did not influence the extent of LA permeation, while high-dose irradiation (0.30 J/cm(2) for 3 times) enhanced the permeation of LA in both the conventional and liposomal formulation. The present results suggest the importance of skin intactness for LA permeation and that the 3D reconstructed skin model would be useful for evaluating the characteristics of skin-oriented cosmetics and drugs.

Linoleic acid (LA) is known to have a whitening effect on hyperpigmented skin, and is encapsulated in liposomes for topical application because of its low solubility in aqueous solution, although the effect of liposomalization of LA on the whitening activity has not been evaluated. In the present study, we evaluated the effect of liposomalization on the whitening activity of LA by using LA in ethanol, hydrogel containing LA, and hydrogel containing liposomal LA towards the UV-stimulated hyperpigmented dorsal skin of brownish guinea pigs. The whitening effect was far greater for hydrogel containing liposomal LA (0.1% w/w as a final concentration of LA) than for free LA in ethanol or hydrogel containing LA. Next, the whitening effect of LA was examined with UV-stimulated hyperpigmented human upper arm skin by using a hydrogel containing liposomal LA (0.1% LA) and non-liposomal LA (3.0, 10.0% LA). Liposomal LA (0.1%) showed a whitening effect comparable to 10.0% non-liposomal LA and was far more effective than 3.0% non-liposomal LA. These results indicate that liposomal formulations are favorable for the transdermal application of LA.

1-Stearoyl-2–[15′-(S)-hydroperoxyicosatetraenoyl]-phospho-serine was synthesized for the first time by utilizing lipoxygenase-catalyzed hydroperoxidation, protection of the hydroperoxy group, DCC-mediated esterification and phospholipase D-catalyzed transphosphatidylation. A hydroxy form of this hydroperoxide was prepared by reducing the hydroperoxy group with triphenylphos-phine. Unoxidized phosphatidylserine was also prepared as a reference compound.

In a sodium deoxycholate micellar solution with calcium chloride, a synthetic phospholipid hydroperoxide was hydrolyzed by porcine pancreatic phospholipase A2 (PLA2) and the reactivity observed for the hydroperoxide was demonstrated to be higher than the case with the unoxidized form. In these systems, it was found that the hydroperoxy group did not directly activate the PLA2.