Amelioration of bowel movement by daily ingestion of Kumaizasa (Sasa. senanensis) powder: A placebo-controlled, randomized, double-blind, parallel-group comparison study

Background: Kumaizasa (Sasa. senanensis (Franchet et Savatier) Rehder) is a bush-type bamboo grown in Hokkaido, Japan and has traditionally been used as a material for herbal medicine and health food. The purpose of this study was to investigate the effect of daily ingestion of Kumaizasa powder (4.2g/day) for 2 weeks for improvement of constipation. We conducted a placebo-controlled, randomized, double-blind, parallel-group comparison study on 80 healthy Japanese men and women between the ages of 20 and 65 who complained of chronic constipation. Results: The stool frequency per week as the primary outcome showed a significant increase after 2-week ingestion of the active food (Kumaizasa powder) compared with the placebo (starch). The stool odor was also significantly improved after 2-week ingestion of Kumaizasa powder compared with the placebo. Abdominal condition was also significantly improved by visual analogue scale (VAS) evaluation. Conclusions: We concluded that daily ingestion of Kumaizasa powder is useful for improvement of constipation.

Search of Neuroprotective Polyphenols Using the “Overlay” Isolation Method

Previous studies of the neuroprotective activity of polyphenols have used ununiform culture systems, making it difficult to compare their neuroprotective potency. We have established a new and simple method for preparing differentiated PC12 cells by removing the toxic coating step. Cells were induced to differentiate with the nerve growth factor (NGF) in a serum-free medium, without a medium change, but with a one-time overlay supplementation of NGF. The optimal inoculation density of the cells was 6–12 × 103 cells/cm2, and the presence of serum inhibited the differentiation. Neuroprotective activity could be quantified by the specific index (SI) value, that is, the ratio of the 50% cytotoxic concentration to the 50% effective concentration. Alkaline extract from the leaves of Sasa senanensis Rehder (SE), having had hormetic growth stimulation, showed the highest SI value, followed by epigallocatechin gallate. The SI value of curcumin and resveratrol was much lower. This simple overly method, that can prepare massive differentiated neuronal cells, may be applicable for the study of the differentiation-associated changes in intracellular metabolites, and the interaction between neuronal cells and physiological factors.

Modeling the effects of individual-tree size, distance, and species on understory vegetation based on neighborhood analysis

Quantifying how understory vegetation responds to individual neighboring trees is critical to understanding forest dynamics. To do so, we used a spatial neighborhood approach to quantify the competitive effect of individual trees on the density and height of dwarf bamboo (Sasa senanensis (Franch. et Savat.) Rehder) in a mixed conifer–broadleaf forest on the island of Hokkaido, northern Japan. Using hierarchical Bayesian models, we analyzed how the effect of neighboring trees varies with stem size, distance to the dwarf bamboo, and tree species. The effect of neighbors peaked when the tree reached a medium size (33.0–45.0 cm in diameter at breast height) and decreased for larger trees. The effect of neighbors decreased with increasing distance to the dwarf bamboo. The slope of the decrease was gentler for larger trees. Conifers exerted an average of 7.2 times the effect of broadleaved trees. Species with higher shade tolerance exerted larger effects. Species with late leaf flush and early defoliation tended to exert smaller effects. Our results provide evidence that neighborhood analysis is an effective approach for quantifying the effects of individual trees on understory vegetation and represents a critical step toward understanding how fine-scale interactions between understory vegetation and trees influence overall forest dynamics.