Propolis is a resinous substance that honeybees collect from plant resins and store inside their hives, where it is used as a supporting material for the nest structure. It has been used as a folk medicine in European and African countries, and in recent times it has attracted popular attention worldwide. In Japan, propolis is used as a supplementary health food and drink supplement. However, the chemical composition of propolis varies greatly according to its geographical and plant origin. The chemical profiles of propolis differ according to plant origin, and the biological activities also tend to differ accordingly. In this paper, we review some representative plant sources of propolis, such as poplar and Baccharis species, and their components. Studies of the anti-microorganism, antioxidant and anti-tumor properties of propolis and its components, as well as the induction of beige adipocyte formation, are also described.

Propolis, a bee product, has antibacterial and antioxidant properties and has been used in folk medicine since ancient times. Brazilian green propolis (BGP), produced in southeastern Brazil, has been reported to demonstrate numerous biological activities in clinical studies. BGP characteristically contains cinnamic acid derivatives such as artepillin C and drupanin. Although these compounds are expected to be active components of BGP, there have been few reports on their pharmacokinetics and metabolism in vivo. We have investigated the blood absorption and metabolism of BGP components after BGP administration in humans and rats, and found that the plasma concentration of total artepillin C, the major component of BGP, was lower than that of total drupanin, which was present at a lower level. Furthermore, it was shown that both the native forms and their hydroxylated metabolites were detected in plasma as their conjugated and unconjugated forms, indicating that their metabolic conversion affected their apparent absorption efficiency. Based on our studies, this review focuses on the pharmacokinetics and metabolism of BGP components, particularly cinnamic acid derivatives, and outlines the prospects for bioavailability studies that will contribute to a better understanding of the functional mechanisms of BGP.

Alzheimer's disease (AD) is an irreversible, progressive neurodegenerative disease characterized by memory loss and cognitive dysfunction, which interferes with independent activities of daily living. AD has been ranked low in terms of both the satisfaction level with the treatment outcomes and the contribution of relevant drugs. For this reason, discovery of effective multifunctional agents with disease-modifying capability is required for successful management of AD. Brazilian green propolis (propolis) is a natural resinous substance produced by Apis mellifera honey bees from the buds of Baccharis dracunculifolia DC (Asteraceae). Propolis mainly consists of caffeoylquinic acid and multiple derivatives of cinnamic acid, including artepillin C, p-coumaric acid, baccharin, and drupanin. Several studies have reported that propolis is effective for treatment of cognitive dysfunction, depressed mood, anxiety, and pain. However, the potential molecular mechanism by which propolis might prevent or ameliorate AD pathology remains unclear. In this review, we summarize current strategies for AD and the potent beneficial effect of propolis on AD pathology.

Propolis has been used for medicinal purposes since ancient times, and recently it has become well established as a health food with a variety of benefits, including anti-inflammatory effects through activation and control of the immune system. We have established a cell lineage-specific calcium biosensor mouse line and a system for real-time visualization of not only immune cell dynamics but also activation using intravital imaging, as well as intestinal sensing of food signals. This facilitates highly sensitive evaluation of the effects of food. Using this system, we have shown that propolis directly stimulates dendritic cells and B cells and exhibits adjuvant activity. In addition, propolis intake increased the activation of dendritic cells in Peyer's patches of the small intestine. It was also suggested that propolis may induce a food signal in small-intestinal epithelial cells, and exert an anti-inflammatory effect via the brain-gut axis mediated by the vagus nerve.

L-Ornithine has recently received considerable attention as a functional amino acid in the fields of nutrition science and health science due to its potential as an anxiolytic-like and/or antifatigue agent. In this study, we used socially isolated mice as a high-stress animal model and investigated whether long-term oral administration of L-ornithine had antistress effects on group-housed or socially isolated mice. For this purpose, we used behavioral and pharmacological methods including the elevated plus maze test, the open field test, the stress-induced hyperthermia test, and the pentobarbital-induced sleep test. In group-housed mice, no effect of L-ornithine treatment was observed in any behavioral test. In the isolated mice, however, the treatment decreased locomotor activity and increased the time spent in the central circle in the open field test. In addition, it increased sleep duration in the pentobarbital-induced sleep test. Performance in the elevated plus maze test and stress-induced hyperthermia test was not affected by the treatment. These findings suggest that long-term oral administration of L-ornithine ameliorates antistress effects on highly stressed socially isolated mice.

The purpose of this study was to compare the values calculated using the Japanese Standard Tables of Food Composition 2015 (7th revision) and 2020 (8th revision) for energy and each nutrient in the menu offered at a special nursing home for the elderly, and to encourage use of the 8th revision in their nutritional management. The data used for analysis were menus, each consisting of 3 meals (breakfast, lunch and a snack) served over 96 days with the energy and nutrient values calculated using the 7th and 8th revisions of the Japanese Standard Tables of Food Composition. The total energy values per day as calculated using the 8th revision were 5.1％ lower than those calculated using the 7th revision. In the case of protein, an important nutrient for energy production, the value based on the 8th revision, calculated from the amino acid composition, was 14.1％ lower than that calculated from the nitrogen content using the 7th revision. These findings suggest that this special nursing home for the elderly underestimated the protein values for the dietary goal. However, as this study was limited to a single facility, further detailed examination using a wider range of subjects will be necessary.