RNA and a cell wall component of Enterococcus faecalis IC-1 are required for phagocytosis and interleukin 12 production by the mouse macrophage cell line J774.1.

Enterococcus faecalis is a resident lactic acid bacterium in the human intestine. Its immunostimulatory action was reported to be enhanced by heat sterilization. To investigate its beneficial actions, we evaluated the ability of 10 E. faecalis strains to induce interleukin-12 (IL-12) production in a mouse macrophage cell line, J774.1 and found that the strain, E. faecalis IC-1, had a potent IL-12-inducing ability. Furthermore, we investigated the underlying mechanism by treating IC-1 cells with RNase or lysozyme. Its activity almost disappeared and an antagonist of Toll-like receptor (TLR) 7 inhibited this activity. Moreover, lysozyme-treated IC-1 bacteria were not phagocytized by J774.1 cells, and did not induce IL-12 production. Based on our results, we propose that macrophages recognize the cell wall components of IC-1, leading to phagocytosis. The IC-1 RNA is then recognized by TLR7, which induces the production of IL-12.

Phase 2 trial of daily, oral epigallocatechin gallate in patients with light-chain amyloidosis.

Previous studies have suggested that an increase in mitochondrial reactive oxygen species may cause organ damage in patients with light-chain (AL) amyloidosis; however, this damage can be decreased by antioxidant-agent treatment. Epigallocatechin gallate (EGCG), the major natural catechin in green tea, has potent antioxidant activity. Because EGCG has recently been reported to have a favorable toxicity profile for treating amyloidosis, we sought to examine the clinical efficacy and toxicity of EGCG in patients with AL amyloidosis. Fifty-seven patients were randomly assigned to the EGCG and observation groups and observed for six months. There were no increases in grade 3-5 adverse events and EGCG therapy was well tolerated. Although a decrease in the urinary albumin level was found in the EGCG group in patients with obvious albuminuria after treatment initiation, its antioxidant activity may not be sufficient to clarify the potential effect of EGCG in patients with AL amyloidosis. Because some of the biological markers responsible for organ damage were well correlated to the level of antioxidant potential in patients' plasma, the status of oxidative stress in the blood may indicate the extent of organ damage in clinical situations.

Effects of green tea consumption on cognitive dysfunction in an elderly population: a randomized placebo-controlled study.

BACKGROUND: Green tea is a beverage with potential effects on cognitive dysfunction, as indicated by results of experimental studies. However, its effects in humans, especially at real-world (typical) consumption levels, are unclear. METHODS: A double-blind, randomized controlled study was conducted to assess the effects of green tea consumption on cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score <28) in Japan. Participants were randomly allocated to the green tea or placebo group, and consumed either 2 g/day of green tea powder (containing 220.2 mg of catechins) or placebo powder (containing 0.0 mg of catechins), respectively, for 12 months. Cognitive function assessments were performed every 3 months using the MMSE-J and laboratory tests. RESULTS: Thirty-three nursing home residents with cognitive dysfunction were enrolled (four men, 29 women; mean age ± SD, 84.8 ± 9.3; mean MMSE-J score ± SD, 15.8 ± 5.4), of whom 27 completed the study. Changes of MMSE-J score after 1 year of green tea consumption were not significantly different compared with that of the placebo group (-0.61 [-2.97, 1.74], least square mean (LSM) difference [95 % CI]; P = 0.59). However, levels of malondialdehyde-modified low-density lipoprotein (U/L), a marker of oxidative stress, was significantly lower in the green tea group (-22.93 [-44.13, -1.73], LSM difference [95 % CI]; P = 0.04). CONCLUSIONS: Our results suggest that 12 months green tea consumption may not significantly affect cognitive function assessed by MMSE-J, but prevent an increase of oxidative stress in the elderly population. Additional long-term controlled studies are needed to clarify the effects. TRIAL REGISTRATION: UMIN000011668.

Green tea catechins prevent low-density lipoprotein oxidation via their accumulation in low-density lipoprotein particles in humans.

Green tea is rich in polyphenols, including catechins which have antioxidant activities and are considered to have beneficial effects on cardiovascular health. In the present study, we investigated the effects of green tea catechins on low-density lipoprotein (LDL) oxidation in vitro and in human studies to test the hypothesis that catechins are incorporated into LDL particles and exert antioxidant properties. In a randomized, placebo-controlled, double-blind, crossover trial, 19 healthy men ingested green tea extract (GTE) in the form of capsules at a dose of 1 g total catechin, of which most (>99%) was the gallated type. At 1 hour after ingestion, marked increases of the plasma concentrations of (-)-epigallocatechin gallate and (-)-epicatechin gallate were observed. Accordingly, the plasma total antioxidant capacity was increased, and the LDL oxidizability was significantly reduced by the ingestion of GTE. We found that gallated catechins were incorporated into LDL particles in nonconjugated forms after the incubation of GTE with plasma in vitro. Moreover, the catechin-incorporated LDL was highly resistant to radical-induced oxidation in vitro. An additional human study with 5 healthy women confirmed that GTE intake sufficiently increased the concentration of gallated catechins, mainly in nonconjugated forms in LDL particles, and reduced the oxidizability of LDL. In conclusion, green tea catechins are rapidly incorporated into LDL particles and play a role in reducing LDL oxidation in humans, which suggests that taking green tea catechins is effective in reducing atherosclerosis risk associated with oxidative stress.

Green tea beverages enriched with catechins with a galloyl moiety reduce body fat in moderately obese adults: a randomized double-blind placebo-controlled trial.

Objective To determine whether ingesting a green tea beverage enriched with catechins with a galloyl moiety during a meal reduces body fat in moderately obese adults. Design Randomized double-blind placebo-controlled study. Subjects A total of 126 obese subjects (25 ≤ body mass index < 30 kg m(-2)) were randomly assigned to a group receiving green tea beverages without catechins (placebo), or a group receiving green tea beverages with a low or high content of catechins with a galloyl moiety. Each subject ingested 500 mL bottled green tea beverages containing 25, 180, or 279.5 mg green tea catechins (0, 149.5, or 246.5 mg catechins with a galloyl moiety, respectively), at mealtimes for 12 weeks; the subjects were instructed to ingest the beverage during the meal that had the highest fat content on that day. Methods Anthropometric measurements and blood chemistry analysis were performed during the run-in period; at weeks 0, 4, 8, and 12 of the intake period; and at the end of the withdrawal period. Abdominal fat area was measured by computed tomography at weeks 0, 8, and 12 of the intake period and at the end of the withdrawal period. Results Both the low- and high-dose groups exhibited significant reductions in visceral and subcutaneous fat areas compared to the control group at 12 weeks post-intervention. Conclusion Ingestion of a green tea beverage enriched with catechins with a galloyl moiety during a high-fat meal reduces body fat in moderately obese adults.

Green tea consumption affects cognitive dysfunction in the elderly: a pilot study.

Green tea is known to have various health benefits for humans. However, the effect of green tea consumption on cognitive dysfunction remains to be clinically verified. We conducted a clinical study to investigate the effects of green tea consumption on cognitive dysfunction. Twelve elderly nursing home residents with cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score: <28) participated in the study (2 men, 10 women; mean age, 88 years). The participants consumed green tea powder 2 g/day for 3 months. After three months of green tea consumption, the participants' MMSE-J scores were significantly improved (before, 15.3 ± 7.7; after, 17.0 ± 8.2; p = 0.03). This result suggests that green tea consumption may be effective in improving cognitive function or reducing the progression of cognitive dysfunction; however, long-term large-scale controlled studies are needed to further clarify the effect.

Oral administration of the extract from Hatakeshimeji (Lyophyllum decastes sing.) mushroom inhibits the development of atopic dermatitis-like skin lesions in NC/Nga mice.

We examined whether the extract from Hatakeshimeji (Lyophyllum decastes, LD) mushrooms suppresses the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of LD extract to NC/Nga mice inhibited the development of AD-like skin lesions based on lower total skin severity scores and serum immunoglobulin E (IgE) levels. Splenic lymphocytes were stimulated with the T cell mitogen concanavalin A, and secretion of a Th1 cytokine (IFN-gamma) and a Th2 cytokine (IL-4) was determined by ELISA. IFN-gamma production was not inhibited by treatment with LD extract. On the other hand, IL-4 production was significantly decreased by treatment with LD extract. These results suggest that LD extract exerts anti-allergic actions by suppressing the serum IgE and Th2-type immune responses.

Radioprotective effect of Lyophyllum decastes and the effect on immunological functions in irradiated mice.

In this study, to explore the radiation protection effects of Lyophyllum Decastes Sing (LDS), a hot distilled-water extract of LDS was orally administered at a dosage of 250mg/kg every other day for a period of 2 weeks in irradiated mice. An automatic blood cell counter was used to measure white blood cells (lymphocytes, monocyte, and granulocytes) one day before X-ray irradiation, and 3 hours, 12 hours, 24 hours, 3 days, 7 days, 15 days and 30 days after irradiation. The Dunnett test was used to examine statistical significance of differences. The peripheral blood cell counts in the Lyophyllum-administered non-irradiation group revealed an increase in the numbers of leukocytes, lymphocytes and monocytes. For 2 Gy whole body radiation, a significant statistical difference was found between the X-ray group and the Lyophyllum plus X-ray group in the numbers of leukocytes, lymphocytes and monocytes. The results suggest that Lyophyllum restrains blood cell-count falling after irradiation, which is probably mediated at least in part by hemopoietic function, and NK and LAK activities seems to play a role in preventing secondary infections associated with irradiation.

Antidiabetic activity of Lyophyllum decastes in genetically type 2 diabetic mice.

The antidiabetic activity of Lyophyllum decastes (Tricholomataceae) was investigated in KK-Ay mice, an animal model of genetically type 2 diabetes with hyperinsulinemia. The water extract of Lyophyllum decastes (LD) (500 mg/kg body weight) reduced the blood glucose of KK-Ay mice 7 h after a single oral administration (p<0.05) when compared with control. LD reduced the blood glucose of KK-Ay mice 3 weeks after repeated administration (p<0.05), and also significantly lowered the serum insulin of KK-Ay mice under similar conditions (p<0.01). However, LD did not affect the blood glucose in normal mice. LD tended to decrease of the blood glucose in an insulin tolerance test. In addition, the muscle content of facilitative glucose transporter isoform 4 (GLUT4) protein content in the plasma membrane fraction from muscle significantly increased in the orally LD-treated KK-Ay mice when compared to that of the controls (p<0.01). These results suggest that the antidiabetic activity of LD is derived, at least in part, from a decrease in insulin resistance, due to the increase of GLUT4 protein content in the plasma membrane of the muscle.

Effect of Hatakeshimeji (Lyophyllum decastes Sing.) Mushroom on serum lipid levels in rats.

The effect of Hatakeshimeji (Lyophyllum decastes Sing.) mushroom on serum lipid levels was investigated in rats. When the mushroom (fruit body) powder or its hotwater extract was added at a level of 10% to a cholesterol-containing diet, the serum total cholesterol levels of rats fed the fruit body or the hot-water extract were markedly lower than that of controls, though there was no significant difference in serum HDL-cholesterol among the three groups. On a cholesterol-free diet, the addition of fruit body powder at a level of 5% significantly decreased serum total cholesterol. Serum triglycerides and phospholipids were significantly decreased in both the fruit body and hot-water extract groups. Furthermore, Hatakeshimeji in the diet significantly increased the activity of cholesterol 7a-hydroxylase, which converts cellular cholesterol to bile acids, as well as the fecal excretion of bile acids.