Dietary galacto-oligosaccharides improve skin health: a randomized double blind clinical trial.

BACKGROUND AND OBJECTIVES: To study the effects of galacto-oligosaccharides (GOS) on the skin, we investigated skin-related parameters in healthy adults who received GOS for 12 weeks. METHODS AND STUDY DESIGN: This double-blind, randomized, placebo-controlled study included subjects divided into two groups (control and GOS) by stratified block randomization. The GOS group received 1.0 g of GOS twice a day, whereas the control group received only vehicle. RESULTS: The results showed that the increase in corneometer values from baseline to week 12 was significantly greater in the GOS group than in the control group (6.91 vs 2.88 arbitrary units, p<0.05). The transepidermal water loss (TEWL) in the GOS group was reduced significantly after 12 weeks of GOS treatment (20.1 g/h/m2 at baseline vs 17.5 g/h/m2 at week 12, p<0.05). The differences in total and percentage of wrinkle areas between the two groups were statistically significant after 12 weeks of GOS treatment (p<0.05). CONCLUSION: Our findings support that oral treatment with GOS is beneficial to the skin and present the possibility of new nutritional strategies for skin care.

L-ascorbic acid addition to chitosan reduces body weight in overweight women.

Previously, we have found that the addition of L-ascorbic acid to chitosan enhanced the reduction in body weight gain in guinea pigs fed a high-fat diet. We hypothesized that the addition of L-ascorbic acid to chitosan would accelerate the reduction of body weight in humans, similar to the animal model. Overweight subjects administered chitosan with or without L-ascorbic acid for 8 weeks, were assigned to three groups: Control group (N=26, placebo, vehicle only), Chito group (N=27, 3 g/day chitosan), and Chito-vita group (N=27, 3 g/day chitosan plus 2 g/day L-ascorbic acid). The body weights and body mass index (BMI) of the Chito and Chito-vita groups decreased significantly (p<0.05) compared to the Control group. The BMI of the Chito-vita group decreased significantly compared to the Chito group (Chito: -1.0 kg/m2 vs. Chito-vita: -1.6 kg/m2, p<0.05). The results showed that the chitosan enhanced reduction of body weight and BMI was accentuated by the addition of L-ascorbic acid. The fat mass, percentage body fat, body circumference, and skinfold thickness in the Chito and Chito-vita groups decreased more than the Control group; however, these parameters were not significantly different between the three groups. Chitosan combined with L-ascorbic acid may be useful for controlling body weight.

Tannase-converted green tea catechins and their anti-wrinkle activity in humans.

BACKGROUND: This study was performed to investigate the anti-wrinkle effects of topical applications of green tea extract with high antioxidant activity by tannase treatment. Increases in gallic acid (GA), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC) were observed in the green tea extract after tannase treatment. OBJECTIVES: This study was performed to investigate the anti-wrinkle effects of topical applications of green tea extract exhibiting high antioxidant activity after tannase treatment. METHODS: Subjects, randomly divided into two groups, received the application of either tannase-converted green tea extract (TGE) or normal green tea extract (NGE) on their crow's feet for 8 weeks. The anti-wrinkle effects were evaluated with two methods: (i) self-assessment; and (ii) average roughness of skin surface (R(a), R(z), and R(t) value) using skin replica and Skin-Visiometer SV 600. RESULTS: The scavenging abilities of TGE against radicals were significantly higher compared to NGE. The evaluation of skin wrinkle index values after 8 weeks of treatment showed that reductions of R(a), R(z), and R(t) values in the TGE group were significantly greater than in the NGE group, which indicated that tannase treatment improved the anti-wrinkle effects of green tea extract. According to the overall ratings for wrinkle treatment by applying the formulations, most of the TGE group (63.60%) reported marked or moderate improvement in wrinkles compared with only 36.30% of the NGE group. CONCLUSION: Tannase treatment can improve the antioxidant activity of green tea extract, conferring anti-wrinkle activities. These results suggest that TGE may have beneficial properties as an anti-wrinkle agent.

Enzymatic improvement in the polyphenol extractability and antioxidant activity of green tea extracts.

This study describes increases in extraction efficiency and the bioconversion of catechins after treatment with several commercial enzymes. Tannase was also used to improve the anti-radical activities of green tea extracts. Enzymatic treatment with various commercial enzymes was introduced to improve the extraction efficiency of polyphenols. The total polyphenol, flavonoid, and catechin contents and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the green tea extract treated with Viscozyme (VG) were significantly higher than those treated with other commercial enzymatic extractions (p<0.05). More than 95% of the epigallocatechingallate (EGCG) and of the epicatechingallate (ECG) was hydrolyzed to epigallocatechin (EGC) and to epicatechin (EC) in successive 20 min treatments with Viscozyme and tannase (TG). Due to its hydrolytic activity, treatment involving tannase resulted in a significant release of gallic acid (GA), EGC, and EC, leading to greater radical scavenging activities. Regarding the IC(50) values of the DPPH and 2,2-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, the green tea extract treated with TG showed values of 131.23 and 28.83 µg/mL, VG showed values of 224.70 and 32.54 µg/mL, and normal green tea extract (NG) showed values of 241.11 and 66.27 µg/mL, respectively. These results indicate that successive treatment with Viscozyme and tannase improves the extraction efficiency of polyphenols and increases radical scavenging activities.

Fermenting red ginseng enhances its safety and efficacy as a novel skin care anti-aging ingredient: in vitro and animal study.

The objective of this study was to evaluate the anti-aging potential and skin safety of red ginseng (RG) and fermented red ginseng (FRG) using Lactobacillus brevis for use as cosmetic ingredients. Concentrations of uronic acid, polyphenols, and flavonoids, and antioxidant activities were greater in FRG compared to RG. The contents of total ginsenosides were not significantly different. However, the ginsenoside metabolite content was higher in FRG (14,914.3 µg/mL) compared to RG (5697.9 µg/mL). The tyrosinase inhibitory activity (IC(50)) of FRG was 27.63 µg/mL, and more potent compared with RG (34.14 µg/mL), (P<.05). The elastase inhibitory activity (IC(50)) of FRG was 117.07 µg/mL also higher compared with RG (157.90 µg/mL). In a primary skin irritation test, 10% RG and 10% FRG were classified as practically nonirritating materials. In a skin sensitization test, the RG group showed a sensitization rate of 100% and its mean evaluation score of irritation was 1.4, whereas the FRG group showed 20% and 0.2%, respectively. By fermentation of RG, FRG has increased contents of ginsenoside metabolites, such as Rg3, Rg5, Rk1, compound K, Rh1, F2, Rg2, and flavonoids content. Therefore, FRG offers increased anti-wrinkle efficacy, whitening efficacy, and reduced toxicological potency compared to RG.

Physical stability, antioxidative properties, and photoprotective effects of a functionalized formulation containing black garlic extract.

When garlic is fermented, certain aspects of its bioactivity are changed. Black garlic is a type of fermented garlic used as a food ingredient in Asian cuisine. Black garlic's popularity has spread around the world as it has become a sought-after ingredient used in high-end cuisine. The formulations containing 10% black garlic extract or 10% normal garlic extract showed stable pH, color, precipitation, and organoleptic features, although these characteristics changed slightly. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the black garlic formulation were significantly (p<0.05) higher compared to those of the base formulation and normal garlic formulation. Mice treated with the black garlic formulation (119.63 µM/g) had significant (p<0.05) decreases in thiobarbituric acid reactive substance (TBARS) levels by lipid peroxidation compared to ultraviolet B (UVB)-control mice (142.37 µM/g). Moreover, significant (p<0.05) prevention of glutathione reduced form (GSH) depletion was observed in the black garlic formulation treated mice (vehicle: 3.46 mM/g vs. black garlic: 5.60mM/g). The formulation containing 10% black garlic extract retained physical stability and had high anti-radical efficiencies. Furthermore, it is possible to suggest that this formulation may be effective in protecting skin from UVB photodamage.

Anti-obesity effects of chitosan and psyllium husk with L-ascorbic acid in guinea pigs.

The aim of this study was to investigate whether L-Ascorbic acid would facilitate the anti-obesity effects of chitosan and psyllium husk in vivo. The study was carried out with male Hartley guinea pigs for 5 weeks. The results show that chitosan itself did not influence body weight gain and food efficiency ratio (FER). However, the addition of L-Ascorbic acid to chitosan decreased these parameters; the body weight gain and FER in the chitosan-2 group (high-fat diet group with 5 % chitosan containing 0.5 % L-Ascorbic acid) was significantly (p < 0.05) lower than that in F-controls (high-fat diet group), and was similar to that in controls (normal diet group). L-Ascorbic acid enhanced significantly (p < 0.05) the increases of total fecal weight and fecal fat excretion by chitosan. The addition of L-Ascorbic acid to psyllium husk did not differ from psyllium husk alone in terms of changes in weight gain, plasma lipid levels, and fat pad weight. We found that the addition of L-Ascorbic acid to chitosan influenced the reduction in body weight gain and FER, and the increase in total fecal weight and fecal fat excretion in guinea pigs fed a high-fat diet.

Photoprotective effects of a formulation containing tannase-converted green tea extract against UVB-induced oxidative stress in hairless mice.

Ultraviolet B (UVB) irradiation may induce the acceleration of skin aging. The purpose of this study was to develop an effective formulation containing tannase-converted green tea extract (FTGE) to inhibit UVB-induced oxidative damage. Significant (p<0.05) prevention of the reduced form of glutathione (GSH) depletion was observed in mice treated with FTGE. The hydrogen peroxide levels of mice treated with FTGE were similar to those of UVB non-irradiated mice. No significant difference was observed between No UVB control and FTGE mice. Also, mice treated with FTGE had significant (p<0.05) decreases in thiobarbituric acid-reactive substance levels by lipid peroxidation compared with No UVB control mice. Our data suggest that this formulation may be effective in protecting skin from UVB photodamage.

Uncooked rice of relatively low gelatinization degree resulted in lower metabolic glucose and insulin responses compared with cooked rice in female college students.

Cooking processes that gelatinize granules or disrupt structure might increase the glucose and insulin responses because a disruption of the structure of starch by gelatinization increases its availability for digestion and absorption in the small intestine. We hypothesized that the uncooked form of rice, which has a relatively low degree of gelatinization even though in powder form, would result in lower metabolic glucose and insulin responses compared with cooked rice (CR). To assess the effects of the gelatinization of rice on metabolic response of glucose and insulin, we investigated the glucose and insulin responses to 3 rice meals of different gelatinization degree in female college students (n = 12): CR (76.9% gelatinized), uncooked rice powder (UP; 3.5% gelatinized), and uncooked freeze-dried rice powder (UFP; 5.4% gelatinized). Uncooked rice powders (UP and UFP) induced lower glucose and insulin responses compared with CR. The relatively low gelatinization degree of UPs resulted in low metabolic responses in terms of the glycemic index (CR: 72.4% vs UP: 49.7%, UFP: 59.8%) and insulin index (CR: 94.8% vs UP: 74.4%, UFP: 68.0%). In summary, UPs that were less gelatinized than CR induced low postprandial glucose and insulin responses.

Effects of yeast hydrolysate on neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) immunoreactivity in rats.

To investigate the appetite regulation mechanism of low and high molecular weight yeast hydrolysate, neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) expressions were analyzed in the brains on rats using immunohistochemical method; normal diet (control), 0.1 g/kg (BY-1) or 1.0 g/kg (BY-2) of yeast hydrolysate below 10 kDa, 0.1 g/kg (AY-1) or 1.0 g/kg (AY-2) of yeast hydrolysate of 10-30 kDa. Body weight gain was lower in the BY-2 (133.0 g) than in the control (150.1 g) (p < 0.05). Triacylglyceride, total cholesterol, and LDL-cholesterol levels were lower in the BY-2 as compared to control, BY-1 and AY-2 (p < 0.05). NPY staining intensities at paraventricular nucleus (PVN) were lower in the BY groups (BY-1: 96.1, BY-2: 88.6) as compared to the control (105.6) and AY groups (AY-1: 110.5, AY-2: 114.1) (p < 0.05). NPY expression at lateral hypothalamic area (LHA) was lower in the BY-2 (92.3) than in the control (98.9) (p < 0.05). The BY groups (BY-1: 143.9, BY-2: 154.6) had higher TPH staining intensities at dorsal raphe (DR) than the AY-2 (115.9) (p < 0.05). In conclusion, the results indicate that administering yeast hydrolysate of below 10 kDa to normal diet-fed rats reduced body weight gain and serum lipids by altering NPY and TPH expressions.

Epigallocatechin gallate stimulates glucose uptake through the phosphatidylinositol 3-kinase-mediated pathway in L6 rat skeletal muscle cells.

The effect of epigallocatechin gallate (EGCG) on glucose uptake was studied in L6 rat skeletal muscle cells. Glucose uptake assay revealed that EGCG increased glucose uptake >70% compared to control. EGCG-stimulated glucose uptake was blocked by LY294002, an inhibitor of phosphatidylinositol (PI) 3-kinase, which is a major regulatory molecule in glucose uptake pathways. However, AMP-activated protein kinase (AMPK), which is another crucial mediator in independent glucose uptake pathways, did not inhibit EGCG-stimulated glucose uptake by SB203585, a specific inhibitor of the AMPK downstream mediator, p38 mitogen-activated protein kinase (MAPK). We also found that EGCG increased the phosphorylation level of protein kinase B and PI 3-kinase activity, when assessed by PI 3-kinase assay, whereas no increase in the phosphorylation level of AMPK and p38 MAPK was observed. Taken together, these results suggest that EGCG might stimulate glucose uptake, not AMPK-mediated but PI 3-kinase-mediated, in skeletal muscle cells, thereby contributing to glucose homeostasis.

Melatonin enhances NADPH-diaphorase activities in the hypothalamus of maternally-separated rats.

Maternal separation or social isolation is a risk factor in the development of mammalian species affecting both physical and mental growth, and food intake regulation. Melatonin has been known to regulate body weight on various species including rodents. We investigated the effect of melatonin treatment on the expression of nitric oxide synthase, which may involved in food intake regulation, in the brain of maternally separated-rats using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Melatonin (10 mg/kg i.p.) was injected to 14-day-old maternally-separated rats for 7 days. Maternally-separated rats with melatonin administration showed significantly higher staining intensities of NADPH-d-positive neurons in the paraventricular nucleus (PVN) and in lateral hypothalamic area (LHA) than maternally-separated without melatonin administration (P < 0.05). Body weight of melatonin treated rats significantly increased at the 6th and 7th day compared to that of rats without melatonin treatment (P < 0.05). These results indicate that melatonin may be associated with increase body weight via NOS in the hypothalamic areas in maternally-separated or socially isolated rats.

Dissimilarity in Fos and Jun immunoreactivity in hypothalamic regions between obese and lean Zucker rats.

The obese Zucker rat, whose genotype is transmitted in an autosomal recessive fashion, is an animal model widely used in the field of obesity. The expression of the nuclear transcription factors c-Fos and c-Jun in the paraventricular nucleus (PVN) and arcuate nucleus (ARC) of the hypothalamus of obese Zucker rats was studied using immunohistochemical methods. PVN and ARC in the hypothalamus are known as centers for the control of food intake. It was observed that the numbers of c-Fos-positive and c-Jun-positive neurons in these regions decreased in obese rats compared to lean rats, and that difference was more evident in the ARC than in the PVN which has to do with the regulation of body weight. The reduction in expression in the ARC of obese rats was greater for c-Jun than for c-Fos. These results suggest a possible difference in Fos immunoreactivity in hypothalamic resistance to circulating satiety factors in genetically obese Zucker rats.