Inhibitory effect of green tea catechins in combination with sucralfate on Helicobacter pylori infection in Mongolian gerbils.

BACKGROUND: The occurrence of antibiotic-resistant Helicobacter pylori has been reported. It is desirable to develop an effective method to prevent the occurrence of resistant strains of Helicobacter pylori. Green tea catechins (GTCs) have been reported to have an antibacterial effect. Therefore, the possibility of eradicating Helicobacter pylori by the oral administration of GTCs was investigated. METHODS: Solutions of GTCs and solutions of GTCs adsorbed to sucralfate (GTC-scf), at concentrations of 20 mg GTCs and/or 20 mg sucralfate/ml were prepared. Then 1 ml of the GTC-scf or the GTC solution was administered daily, for 10 days to Mongolian gerbils infected with Helicobacter pylori. Then the stomachs were extirpated and homogenized. The homogenate was spread on selective medium plates. After 5-day culture, colony-forming units (CFU) of Helicobacter pylori were counted. RESULTS: The CFU of Helicobacter pylori was significantly decreased by GTC-scf. CONCLUSIONS: GTC-scf may have a bactericidal effect on Helicobacter pylori infection.

Depressive symptoms are independently correlated with lipid peroxidation in a female population: comparison with vitamins and carotenoids.

OBJECTIVE: Lipid peroxidation (LPO) is involved in oxidative tissue injuries. The present investigation examined the association between LPO and psychological depressive symptoms. METHODS: A cross-sectional study was conducted on 66 female volunteers aged 38-70. Lipid peroxides (LOOH) in serum were evaluated by hemoglobin-methylene blue (Hb-MB) method; additionally, serum antioxidants were also detected. To assess depressive symptoms, the Center for Epidemiologic Studies Depression (CES-D) Scale and a subscale in the 28-item General Health Questionnaire (GHQ) were applied. RESULTS: LOOH concentration displayed a significant positive correlation with CES-D and GHQ depression scores. Multiple regression analysis was performed in which LOOH concentration served as a dependent variable and CES-D scores and antioxidants as independent variables. Consequently, CES-D scores demonstrated significant positive correlation with LOOH. CONCLUSIONS: The positive relationship between depressive symptoms and LPO in a female population may support the hypothesis that LPO may affect depressive symptoms.

Inhibitory effects of autoimmune disease by green tea in MRL-Faslprcg/Faslprcg mice.

To investigate whether green tea has inhibitory effects on the development of autoimmune disease (AID), one-month-old MRL-Faslprcg/Faslprcg mice were fed diets containing 2% green tea powder (GTP) for 3 months. At the end of GTP feeding, the weights of body, subcutaneous (s.c.) and intraperitoneal (i.p.) lymph nodes (LN), kidneys, spleen and intraperitoneal adipose tissue (IPAT), serological abnormalities and renal lesions were compared between GTP-fed and control mice. SCLN, IPLN, kidneys and IPAT weights in both sexes, spleen weight in males and body weight increase in males were significantly lower in GTP-fed mice. Particularly, LN hyperplasia and fatty accumulation were markedly reduced by GTP. Serum levels of anti-DNA antibodies and immune complexes (IC) were significantly lowered and proteinuria and blood urea nitrogen tended to be improved by GTP. The incidence of serious glomerulonephritis was significantly lower and nephric vasculitis was almost completely prevented in GTP-fed mice. Moreover, the survival of mice was significantly prolonged by GTP feeding for 6 months. These results indicate that the progression of lupus-like syndrome including glomerulonephritis was significantly delayed by reduced production of autoantibodies and IC in GTP-fed MRL-Faslprcg/Faslprcg mice, which led to the prolonged survival.

Anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, in mice.

To elucidate the anti-obesity effects of three major components of green tea, catechins, caffeine and theanine, female ICR mice were fed on diets containing 2% green tea powder and diets containing 0.3% catechins, 0.05% caffeine and 0.03% theanine, which correspond, respectively, to their concentrations in a 2% green tea powder diet, singly and in combination for 16 weeks. Body weight and food intake were determined monthly during this period, kidneys, adrenals, liver, spleen, brain, pituitary and intraperitoneal adipose tissues (IPAT) were weighed and lipid levels in the serum and liver were measured at the end of this period. The body weight increase and weight of IPAT were significantly reduced by the diets containing green tea, caffeine, theanine, caffeine + catechins, caffeine + theanine and caffeine + catechins + theanine. Noticeably, the IPAT weight decreased by 76.8% in the caffeine + catechins compared to the control group. Serum concentrations of triglycerides (TG) and non-esterified fatty acids (NEFA) were decreased by green tea, catechins and theanine. Moreover, caffeine + catechins, caffeine + theanine and caffeine + catechins + theanine also decreased NEFA in the serum. The TG level in the liver was significantly reduced by catechins and catechins + theanine in comparison with the control. These results indicated that at least caffeine and theanine were responsible for the suppressive effect of green tea powder (GTP) on body weight increase and fat accumulation. Moreover, it was shown that catechins and caffeine were synergistic in anti-obesity activities.

Tissue distribution and intracellular localization of catechins in tea leaves.

We investigated the leaf tissue and cellular morphology of tea (Camellia sinensis). Osmiophilic material, presumably catechins, was present in mesophyll cells, but not in epidermal cells. Electron microscopy showed that catechins were localized to restricted regions within the central vacuoles. In addition, two kinds of small vacuoles of 0.5-3 microm were present in mesophyll cells. One vacuole had catechins within its whole lumen, while the other had an electron-lucent lumen. We found fusion profiles between a large central vacuole and these small vacuoles. We propose that after catechins are synthesized, they are incorporated into small vacuoles and transported to the large central vacuoles.