[Inhibitory effects of "Goishi-tea" as a post-fermented-tea on dietary-induced hypercholesteremia and atherosclerosis in rabbits]

Improvement of blood lipid profiles by Goishi tea polyphenols in a randomised, double-blind, placebo-controlled clinical study

Dyslipidaemia is a risk factor for arteriosclerosis. Recent studies have shown that dyslipidaemia is effectively prevented by various polyphenols. In this clinical study (UMIN trial: 000024028), we evaluated the beneficial effects of polyphenols contained in Goishi tea on blood lipid profiles. Seventy-seven subjects with LDL cholesterol (CHO) ≧120 mg/mL were randomly divided into two groups for 12 weeks of polyphenol intake as follows: the Goishi tea group for daily consumption of Goishi tea containing 122 mg of polyphenols and the placebo group for the corresponding consumption of a placebo drink containing 12.2 mg of polyphenols. Intake of Goishi tea polyphenols tended to increase HDL CHO and suppress the elevation of triglycerides. These effects were particularly notable among the subjects with a body mass index <25 kg/m². These findings suggest that Goishi tea polyphenols may suppress arteriosclerosis and reduce cardiovascular event risk by improving blood lipid profiles and thereby preventing dyslipidaemia.

Application of Natural Ingredients to Preventive Medicine

The super-aging society in Japan is currently experiencing growing demand for treatments that improve health and longevity. To develop new high-functional foods and search for pharmaceutical candidates among foods and natural products, it is necessary to promote organic collaboration among researchers in pharmacy, medicine, nutrition, and other fields to encourage joint utilization of their technologies. Recently, attempts have been made to use numerous foods and natural products to prevent or treat diseases based on scientific evidence. We have been endeavoring to develop preventive medicines from foods and natural ingredients by engaging in relevant activities such as screening these substances to determine the structures of their effective ingredients, verifying pharmacological activities, and conducting clinical trials. In this study, the effectiveness of Goishi tea (postfermented tea) and Flos Lonicerae (Japanese honeysuckle) for metabolic syndrome and hepatic disorders, respectively, was explored. Multicomponent foods and natural ingredients have diverse effects produced by the actions of individual components as well as the interactions among different components. Additionally, when using natural ingredients and similar materials, it is necessary to consider the different extraction efficiencies of various methods and their absorption, deposition, metabolism, and excretion after consumption. The influence of intestinal bacteria and other factors is also critical. In our study, the administration of Goishi tea and Flos Lonicerae in animal models of disease demonstrated high functionality. Based on these findings, we plan to conduct further investigations, including clinical studies in human participants, focusing on the potential usefulness of Goishi tea and Flos Lonicerae as functional foods.

Goishi tea consumption inhibits airway hyperresponsiveness in BALB/c mice

Background

Airway hyperresponsiveness (AHR) is one of the important traits that characterize bronchial asthma. Goishi tea is a post-heating fermented tea that has been reported to have higher free radical scavenging activity. In this study, we evaluated the prophylactic effects of Goishi tea on AHR in BALB/c mice.

Results

The number of inflammatory cells in BAL fluid was considerably reduced in Goishi tea/Der f and Gallic acid/Der f groups as compared with Tap water/Der f group. Regarding inflammatory cells in BAL, a significant reduction of eosinophils and neutrophils was observed in Goishi tea-treated mice (p < 0.01), as well as in the Gallic acid/Der f group (p < 0.05), as compared with Tap water/Der f group. In asthmatic mice (Tap water/Der f group), the intensity of airway resistance increased simultaneously with the increase in acetylcholine concentration in a dose-dependant way. AHR was significantly inhibited in Goishi tea/Der f and Gallic acid/Der f (p < 0.01) groups as compared with the Tap water/Der f group. Regarding serum specific-IgG₁, significantly lower levels of this antibody were observed in Goishi tea/Der f and Gallic acid/Der f groups as compared with the Tap water/Der f group (p < 0.05). In addition, adiponectin level was significantly higher in the Goishi tea group as compared with the Tap water treated mice (p < 0.01).

Conclusions

The results suggest that Goishi tea consumption exerted an inhibitory effect on eosinophilic and neutrophilic infiltration in the lung, attenuated the increase in airway resistance and increased the production of adiponectin; thus reducing Der f induced allergic inflammatory process in mice.