Thirteen compounds were isolated from the Canavalia lineata pods and their inhibitory activities against human monoamine oxidase-A (hMAO-A) and -B (hMAO-B) were evaluated. Among them, compounds 8 (medicarpin) and 13 (homopterocarpin) showed potent inhibitory activity against hMAO-B (IC₅₀ = 0.45 and 0.72 µM, respectively) with selectivity index (SI) values of 44.2 and 2.07, respectively. Most of the compounds weakly inhibited MAO-A, except 9 (prunetin) and 13. Compounds 8 and 13 were reversible competitive inhibitors against hMAO-B (K_i = 0.27 and 0.21 µM, respectively). Structurally, the 3-OH group at A-ring of 8 showed higher hMAO-B inhibitory activity than 3-OCH3 group at the A-ring of 13. However, the 9-OCH3 group at B-ring of 13 showed higher hMAO-B inhibitory activity than 8,9-methylenedioxygroup at the B-ring of 12 (pterocarpin). In cytotoxicity study, 8 and 13 showed non-toxicity to the normal (MDCK) and cancer (HL-60) cells and moderate toxicity to neuroblastoma (SH-SY5Y) cell. Molecular docking simulation revealed that the binding affinities of 8 and 13 for hMAO-B (−8.7 and −7.7 kcal/mol, respectively) were higher than those for hMAO-A (−3.4 and −7.1 kcal/mol, respectively). These findings suggest that compounds 8 and 13 be considered potent reversible hMAO-B inhibitors to be used for the treatment of neurological disorders.

In this study, we investigated the physiological responses and particulate matter (PM) abatement and adsorption of three plants: Ardisia crenata, Ardisia japonica, and Maesa japonica, to determine their effectiveness as indoor air purification. When compared to control (without plants), PM was significantly and rapidly decreased by all three plants. The reduction in PM varied by species, with A. crenata being the most effective, followed closely by A. japonica, and finally M. japonica. M. japonica showed the highest rate of photosynthesis and transpiration, generating the greatest decrease in CO₂ and a large increase in relative humidity. We hypothesize that the increased relative humidity in the chamber acted in a manner similar to a chemical flocculant, increasing the weight of PM via combination with airborne water particles and the creation of larger PM aggregates, resulting in a faster sedimentation rate. A. crenata had a stomatal size of ~20 μm or larger, suggesting that the PM reduction observed in this species was the result of direct absorption. In the continuous fine dust exposure experiments, chlorophyll fluorescence values of all three species were in the normal range. In conclusion, all three species were found to be suitable indoor landscaping plants, effective at reducing indoor PM.

We aimed to develop a horticultural therapy program to prepare adolescents at the Dae san juvenile detention center (D-JDC) for their return to society. The effects of the program on emotional stability and career exploration were investigated. Adolescents who wished to participate in the horticultural therapy program were recruited from the D-JDC. Data were collected using various questionnaires before and after the program was implemented. Thirty-five (mean age, 15.74 ± 1.65 years; 11 males, 24 females) students were enrolled. The program mainly consisted of plant cultivation activities, such as seeding, transplanting plants, cutting, harvesting, and post-harvest utilization. To evaluate emotional health, the ego-resiliency scale was used. To evaluate social behavior, the inventory of parent and peer attachment, peer attachment scale, and social skills scale were used. Career exploration was assessed using the career preparation behavior scale and the career decision-making self-efficacy-short form. Peer attachment, social skills, and career preparation behavior showed significant improvements after the program, with the students responding positively in the post-program surveys. Our horticultural therapy program helped improve the career exploration and social skills of D-JDC students and positively affected their emotional stability. Based on our findings, horticultural therapy can be used as a correctional program for adolescents in D-JDC to help them return to society.

The bioactive components of Canavalia lineata (Thunb.) DC pods were investigated using bioactivity-guided isolation, and the chemical structures of flavonoids 1–3, isoflavonoid derivatives 4–11, and phenolic compounds 12 and 13 were identified by comparing NMR, MS, and CD spectral data with previously reported spectroscopic data. Compounds 1–13 were evaluated for their anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages. Among these compounds, the isoflavonoid derivative cajanin (7) exhibited the most potent anti-inflammatory activity (IC₅₀ of NO = 19.38 ± 0.05 µM; IC₅₀ of IL-6 = 7.78 ± 0.04 µM; IC₅₀ of TNF-α = 26.82 ± 0.11 µM), exerting its anti-inflammatory effects by suppressing the activation and nuclear translocation of the transcription factor NF-κB by phosphorylating IκB and p65. These results suggested that cajanin (7) may be a potential candidate for improving the treatment of inflammatory diseases.

Astragalus sikokianus is a rare Japanese perennial of the seashore that was reported to be extinct in the wild. The small seed size and deep dormancy of A. sikokianus make it difficult for direct seeding restoration in aspects of seed handling, transport, planting, and seedling establishment. For the large-scale economic restoration of dormant small-seeded species, seed pelleting combined with the breaking of dormancy was studied. Physiological (prechilling and plant hormones) and physical (hot water, hydrochloric acid, and sulfuric acid) seed dormancy break treatments were evaluated. The dormant broken seeds were used for pelleting. The effects of the substrate, pellet sizes, and their interactions on germination were measured. The scarification of five rubs of seeds placed between sandpapers completely broke the physical dormancy of A. sikokianus. Seed coat impermeability inhibited germination. Pelleted seeds ranging from 2.0 to 4.0 mm in diameter showed more than 90% germination on filter paper. The germination of the pelleted seeds was measured in commercial, field, and sand soil conditions. The highest germination was shown in sand (70–74% GP), regardless of the pellet size, whereas unpelleted scarified seeds germinated only 48%. These results suggest that small-seeded species with physical dormancy can be used for seed-based restoration after seed pelleting.

A better understanding of seed dormancy and germination temperature requirements is necessary for successful propagation of rare and endangered plant species. Here, we describe suitable methods to improve the germination of Dysophylla yatabeana seeds. Seeds pre-soaked in 1000 mg L^-1 GA₃ solution for 24 hours were incubated at 15, 20, 25, 30 and 35°C. Germination of over 70% was obtained at 30 and 35°C, but only 50% germination was attained at 15, 20 and 25°C. Seeds incubated at 30°C after soaking in 400, 800 and 1000 mg L^-1 GA₃ solutions showed > 50% germination, but lower GA₃ concentrations (0 and 200 mg L^-1) resulted in < 10% germination. Endogenous abscisic acid (ABA) levels showed a greater decrease in seeds treated with 400, 800 and 1000 mg L^-1 GA₃ compared with seeds treated with 0 and 200 mg L^-1 GA₃, indicating that endogenous ABA is responsible for dormancy in D. yatabeana seeds. Dysophylla yatabeana seeds have strong dormancy and can hardly germinate at low temperature regimes even after GA₃ treatment.