Alnus hirsuta (Spach) Rupr. Attenuates Airway Inflammation and Mucus Overproduction in a Murine Model of Ovalbumin-Challenged Asthma

Alnus hirsuta (Spach) Rupr. (AH), a member of the Betulaceae family, is widely used in Eastern Asia of as a source of medicinal compounds for the treatment of hemorrhage, diarrhea, and alcoholism. In this study, we investigated the protective effects of a methanolic extract of AH branches against airway inflammation and mucus production in tumor necrosis factor (TNF)-α-stimulated NCI-H292 cells and in an ovalbumin (OVA)-challenged allergic asthma mouse model. Female BALB/c mice were injected with OVA (40 μg) and aluminum hydroxide (2 mg) on days 0 and 14 to induce allergic airway inflammation. The mice were then challenged with 1% OVA from days 21–23. Mice were treated with AH (50 and 100 mg/kg/day; 2% DMSO) or dexamethasone (positive control; 3 mg/kg/day) from days 18–23. AH treatment effectively attenuated airway resistance/hyperresponsiveness and reduced levels of T helper type 2 (Th2) cytokines, eotaxins, and number of inflammatory cells in bronchoalveolar lavage fluid, and immunoglobulin E in serums of OVA-challenged mice. In histological analysis, AH treatment significantly inhibited airway inflammation and mucus production in OVA-challenged mice. AH treatment downregulated the phosphorylation of I kappa B-alpha, p65 nuclear factor-kappa B (p65NF-κB), and mitogen-activated protein kinases with suppression of mucin 5AC (MUC5AC) in lung tissue. Moreover, AH treatment decreased the levels of pro-inflammatory cytokines and Th2 cytokines, as well as MUC5AC expression, and inhibited the phosphorylation of p65NF-κB in TNF-α-stimulated NCI-H292 cells. These results indicate that AH might represent a useful therapeutic agent for the treatment of allergic asthma.

Root Responses of Five Japanese Afforestation Species to Waterlogging

The increase of waterlogged environments is of recent concern due to changes in precipitation regimes and the frequent occurrence of extreme rainfall events. Therefore, it is necessary to comprehend the effects and responses of waterlogging for a better understanding of forests and urban afforestation under changing environments. We investigated root responses of five Japanese afforestation species (Pinus thunbergii, Acer mono, Quercus serrata, Alnus hirsuta and Fraxinus mandshurica) to waterlogging. Potted seedlings grown under natural conditions were waterlogged at soil-surface level for 2.5 months during the growing season. The in-growth core method was used to distinctively measure root growth. As a result, fine root growth during the waterlogging period was significantly decreased for P. thunbergii, A. mono and Q. serrata. Furthermore, root tissue density (RTD) of pre-existing roots was decreased, which suggests root damage such as partial root death and root decay. On the other hand, for A. hirsuta and F. mandshurica, fine root growth was not decreased under waterlogging. For A. hirsuta, although fine root growth continued at the top half, it was decreased at the bottom half. Root damage such as a decrease in RTD was observed for pre-existing roots. For F. mandshurica, root growth continued at the top and bottom half, and root damage of pre-existing roots was not observed at either the top or the bottom. From our results, it was suggested that P. thunbergii was most sensitive, followed by A. mono and Q. serrata. A. hirsuta and F. mandshurica were relatively tolerant; however, the most tolerant was F. mandshurica, as pre-existing roots were not damaged by waterlogging. Overall, root responses could be grouped into three groups: (1) P. thunbergii, A. mono, Q. serrata; (2) A. hirsuta; (3) F. mandshurica. The observed responses may reflect the species’ natural distributions.

Activation of JNK and p38 in MCF-7 Cells and the In Vitro Anticancer Activity of Alnus hirsuta Extract

JNK and p38 are important mitogen-activated protein kinases (MAPKs) that respond to stress stimuli. The stress-activated MAPKs associated with apoptotic cell death play vital roles in mammalian cells. Alnus hirsuta, which contains abundant diarylheptanoids derivatives, is a valuable medicinal plant. The CHCl3 extract (AHC) containing platyphyllenone (1) and platyphyllone (3) as main compounds showed in vitro anticancer effects. We report the biological activities of A. hirsuta extract associated with the regulation of apoptosis and JNK and p38 in MCF-7 breast cancer cells. Levels of phospho-JNK and phospho-p38 by AHC treatment were evaluated by enzyme-linked immunosorbent assay (ELISA). ROS production, apoptotic effect, and DNA contents of the cells were measured by flow cytometry. The two diarylheptanoids 1 and 3 and the AHC extract exhibited cytotoxic effects on MCF-7 cells in MTT assay, with IC50 values of 18.1, 46.9, 260.0 μg/mL, respectively. AHC induced ROS generation and elevated the endogenous levels of phospho-JNK and phospho-p38. AHC resulted in apoptosis and cell cycle arrest. We suggest that the antitumor effect of A. hirsuta extract is achieved by apoptosis promotion and cell cycle arrest mediated by the activation of JNK and p38 signaling pathway via ROS generation.

CONTENTS OF HEAVY METALS IN THE PLANTS OF PETROPAVLOVSK-KAMCHATSKY (KAMCHATKA TERRITORY) IN 2017–2018

Results of determining the content of zinc, copper, lead and cadmium in the leaves of Alnus hirsuta, Artemi-sia vulgaris kamtschatica, Betula ermanii, Rosa amblyotis, Salix udensis collected from the territories of Petropavlovsk-Kamchatsky in 2017–2018 summer period are discussed. In the summer of 2017, the copper content in the plants from studied areas varied in the range from 5.5 to 22.5 mg/kg, in 2018 – from 7.7 to 36.6 mg/kg. Its highest content in 2017 and 2018 was found in A. vulgaris, and the lowest in R. amblyotis. In 2017, the concentration of zinc varied from 12.9 to 281 mg/kg, in 2018 – from 20.8 to 246 mg/kg, the high-est concentration in 2017 and 2018 is typical for S. udensis, the lowest for R. amblyotis. In 2017, the range of lead content in plant samples was from 0.3 to 3.0 mg/kg, in 2018 – from 1.2 to 3.8 mg/kg. In the summer of 2017, the cadmium content in studied plant samples varied in the range from 0.2 to 2.7 mg/kg, in 2018 – from 0.1 to 3.6 mg/kg. The lowest concentration of cadmium was found in 2017 in R. amblyotis, in 2018 – B. ermanii, the highest in the leaves of S. udensis in 2017 and 2018. Our results allowed identifying species – indicators of metal pollution for the territories of Petropavlovsk-Kamchatsky: A. vulgaris kamtschatica from the representatives of the herbaceous-shrub layer and S. udensis from the tree layer.

Three new species of parasitaphelenchids, Parasitaphelenchus frontalis n. sp., P. costati n. sp. and Bursaphelenchus hirsutae n. sp. (Nematoda: Aphelenchoididae), isolated from bark beetles from Japan

Summary Three parasitaphelenchid species, Parasitaphelenchus frontalis n. sp., P. costati n. sp. and Bursaphelenchus hirsutae n. sp., are described. Parasitaphelenchus frontalis n. sp. was isolated from the body cavity of Scolytus frontalis emerging from dead logs of Zelkova serrata collected from Kanagawa, Japan, and characterised by its four-lined lateral field in the adults and dome-shaped lip region of the parasitic juveniles. Whereas the two first-mentioned species were isolated from Alniphagus costatus, B. hirsutae n. sp. emerged from dead logs of Alnus hirsuta collected from Nagano, Japan. Parasitaphelenchus costati n. sp. and B. hirsutae n. sp. were recovered from the body cavity and the underside of the elytra of their host/carrier beetle, respectively. Parasitaphelenchus costati n. sp. is characterised by its three-lined lateral field in adults and the presence of a ventrally-directed hook on the lip region of the parasitic juvenile. Bursaphelenchus hirsutae n. sp. belongs to the eggersi group of the genus and is characterised by its three-lined lateral field, dorsally truncate condylus and pointed rostrum of males, and long, smoothly tapering and strongly ventrally recurved, female tail. Molecular characterisation is provided for all three new species and their phylogenys discussed.