Jae-Min Chung

Prunus spachiana (Lavallée ex Ed.Otto) Kitam. f. ascendens (Makino) Kitam leaves exert natural anti-inflammatory effects by inhibiting nitric oxide formation. P. spachiana flowers bloom earlier than other Prunus spp. and thus could serve as a valuable resource for the horticulture and pharmaceutical industries. However, its seed dormancy class and germination traits remain uncharacterized. Thus, this study aimed to characterize the seed dormancy and germination of P. spachiana. Imbibition, phenological, and move-along experiments were performed, and the effects of H₂SO₄ treatment, hormone soaking, warm/cold stratification, and endocarp removal on germination were explored. Observation revealed that ripe seeds of P. spachiana contain developed embryos and are water permeable. Radicle and shoot emergence began in March and April, respectively, under natural conditions in the year following production. No seed germination was observed after 30 days of incubation at 4, 15/6, 20/10, or 25/15 °C under light/dark conditions, indicating the physiological dormancy of the seeds. Germination increased with prolonged stratification and was affected by incubation temperature. Seed scarification by H₂SO₄ and soaking with gibberellic acid (GA₃) and fluridone were ineffective in breaking dormancy. However, GA₃ soaking of the seeds after endocarp removal effectively induced germination (100%). These results indicate that P. spachiana seeds exhibit intermediate physiological dormancy.

Introduction: Magnolia kobus DC has been used as herbal medicine to treat coughs and is known to exert biological effects such as anti-inflammatory, antioxidant, and antibacterial properties. We aimed to define the pharmacological effects of M. kobus leaf ethanol extract (MLEE) on acute lung inflammation and explore the underlying mechanisms of action. Methods: For in vitro investigations, RAW 264.7 cells were pretreated with MLEE (1, 10, and 100 μg/mL) and stimulated with lipopolysaccharide (LPS). For in vivo investigations, BALB/c mice were intratracheally administered with LPS for 24 hours after injection of MLEE (0.3, 3, and 30 mg/kg). Hematoxylin and eosin staining was used for histopathology analysis of lung tissue. The phytochemical constituents of MLEE were analyzed using high-performance liquid chromatography. Results: In RAW 264.7 cells, MLEE reduced the activation of the inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-2) and the nuclear translocation of nuclear factor (NF)-κB and nuclear factor erythroid-2-related factor 2 (Nrf2). The intraperitoneal injection of MLEE (30 mg/kg) attenuated interstitial edema and immune cell infiltration in LPS-induced acute lung inflammation. MLEE also inhibited the activation of cyclooxygenase-2, NF-κB, and Nrf2 in the lung tissue. Conclusion: Taken together, MLEE exerted an anti-inflammatory effect by inhibiting inflammatory and oxidative mediators on acute lung inflammation suggesting that it might be used as a natural drug for treating acute lung inflammatory diseases.

The genetic structure of temperate plants in the northern hemisphere was significantly influenced by the Quaternary climate oscillations. A species' biological characteristics and ecological niche are significant elements that can affect its phylogeographic history. We adopted the cold-tolerant, anemophilous and anemochorous tree, Populus koreana, as a model species to examine the impact of historical climate changes and biological characteristics on the evolutionary history of vegetation in Northeast Asia throughout the Quaternary period. The results showed that there is moderate genetic differentiation and a lack of phylogeographic structure among populations of P. koreana based on nuclear microsatellite and plastid markers. Demographic analyses and ecological niche modeling suggested that P. koreana is likely to have experienced a bottleneck around the last glacial maximum (LGM), followed by a rapid and continued range expansion coupled with a northward migration from the LGM to the mid-holocene (MH), present, and 2050. Notably, there were several separate refugia present throughout the range of P. koreana in Northeast Asia during the LGM. These include two widely recognized refugia located in the Changbai Mountains and the southern Korean Peninsula. We also unexpectedly found a previously unknown one in the northern Greater Khingan Mountains. Our study contributes to the understanding of the phylogeographic history of plant species in Northeast Asia, providing novel insights into the Greater Khingan Mountains as glacial refugia for a cold-tolerant tree species. These findings provide valuable insights into the Quaternary historical patterns of temperate forests in East Asia.

Introduction: Rhododendron brachycarpum D. Don ex G. Don(RbGD) leaves have traditionally been used to treat diabetes, rheumatoid arthritis, hypertension, and skin ailments. Although RbGD leaves are used as a medicinal plant, there is no scientific evidence to support skin treatment. Therefore, the purpose of this study was to look into the anti-inflammatory effect of an ethanolic extract of RbGD on skin disease, specifically atopic dermatitis (AD). Methods: The anti-inflammatory effect of RbGD ethanol leaf extract (RbGDE) on tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-activated keratinocytes was evaluated using MTT, qPCR, ELISA, and Western blot Procedures. The therapeutic effects of RbGDE were evaluated in vivo inflammatory responses by histological observation, quantitative polymerase chain reaction (qPCR), and ELISA using the 1-chloro-2,4-dinitrobenzene (DNCB)/Dermatophagoides farina extract (DfE)-induced AD-like skin mouse model. Results: RbGDE showed the protective effect against irritating and stimulating substances (H2 O2 and TNF-α/IFN-γ) and inhibited TNF-α/IFN-γ-activated keratinocytes by inhibiting the p38 mitogen-activated protein kinase and nuclear factor-kappa B activation. Furthermore, topical RbGDE treatment reduced the AD features such as thickened skin, erythema, immune cells infiltration (eosinophils and mast cells), and AD-related cytokines (IL-12a, IL-1β, IL-4, and TSLP) in the ear tissues of DNCB/DfE-induced mice. The RbGDE also reduced histamine and immunoglobulins (Igs) levels in the serum, including DfE-specific IgE, total IgE, and IgG2a. Conclusion: RbGD leaf extract had an anti-inflammatory effect on dermatitis by reducing inflammatory mediators, indicating that it might be used to treat skin disease.

Microtube-like porous carbon (MPC) and tube-like porous carbon–sulfur (MPC-S) composites were synthesized by carbonizing milkweed pappus with sulfur, and they were used as cathodes for lithium–sulfur batteries. The morphology and uniformity of these materials were characterized using X-ray powder diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy with an energy-dispersive X-ray analyzer, thermogravimetric analysis, and X-ray photoelectron spectrometry. The electrochemical performance of the MPC-S cathodes was measured using the charge/discharge cycling performance, C rate, and AC impedance. The composite cathodes with 93.8 wt.% sulfur exhibited a stable specific capacity of 743 mAh g⁻¹ after 200 cycles at a 0.5 C.

Saussurea namhaedoana, a new endemic species narrowly restricted to Namhaedo Island of Korea, is reported in this study. It can be distinguished from other congeneric species of Saussurea in Korea by having persistent radical leaves until flowering, hastate or sagittate leaves with mucronate toothed to undulate-lobulate margins, grayish cobwebby hairs on abaxial leaf surfaces when young, and tubular involucre with grayish cobwebby hairs. Morphologically, S. namhaedoana is closely related to other species in Korea, such as S. gracilis Maxim., S. insularis Kitam., S. seoulensis Nakai and S. albifolia M. J. Nam and H. T. Im, sharing grayish or white hairs on the abaxial leaf surfaces. It, however, can be distinguished from its close relatives by having a distinct leaf shape, i.e., sagittate or hastate leaves. The phylogenetic relationship relative to congeners in East Asia is yet to be determined.

Veronicastrum sibiricum is a perennial species distributed in Korea, Japan, Manchuria, China, and Siberia. This study aimed to determine the requirements for germination and dormancy break of V. sibiricum seeds and to classify the kind of seed dormancy. Additionally, its class of dormancy was compared with other Veronicastrum and Veronica species. V. sibiricum seeds were permeable to water and had a mature embryo during seed dispersal. In field conditions, germination was prevented by physiological dormancy, which was, however, relieved by March of the next year, allowing the start of germination when suitable environmental conditions occurred. In laboratory experiments, the seeds treated with 0, 2, 4, 8, and 12 weeks of cold stratification (4 °C) germinated to 0, 79, 75, 72, and 66%, respectively. After the GA₃ treatment (2.887 mM), ≥90% of the seeds germinated during the four incubation weeks at 20/10 °C. Thus, 2.887 mM GA₃ and at least two weeks at 4 °C were effective in breaking physiological dormancy and initiating germination. Therefore, the V. sibiricum seeds showed non-deep physiological dormancy (PD). Previous research, which determined seed dormancy classes, revealed that Veronica taxa have PD, morphological (MD), or morphophysiological seed dormancy (MPD). The differences in the seed dormancy classes in the Veronicastrum-Veronica clade suggested that seed dormancy traits had diverged. The results provide important data for the evolutionary ecological studies of seed dormancy and seed-based mass propagation of V. sibiricum.

We report a previously unrecorded woody species, Stachyurus praecox Siebold & Zucc. (Stachyuraceae), in Korea. This species is considered to be endemic to Japan. Stachyurus praecox was collected for the first time in an evergreen forest on an uninhabited island of Bongsun-ri, Saengil-myeon, Wando-gun, Jeollanam-do in Korea. The inflorescence of the species was racemose and pendulous on the axils of the previous year’s branches. Flowers bloomed from March to April. They were functionally dioecy but morphologically hermaphrodite. This woody species was named ‘Wan-do-sul-kkot-na-mu’ in Korean based on the shape of its inflorescence. Morphological characteristics and illustrations of this woody species have been provided with a distribution map and photographs of the natural habitat.