A cytotoxic secocycloartenoid from Abies koreana

Transcriptomic Insights into Abies koreana Drought Tolerance Conferred by Aureobasidium pullulans AK10

The conservation of the endangered Korean fir, Abies koreana, is of critical ecological importance. In our previous study, a yeast-like fungus identified as Aureobasidium pullulans AK10, was isolated and shown to enhance drought tolerance in A. koreana seedlings. In this study, the effectiveness of Au. pullulans AK10 treatment in enhancing drought tolerance in A. koreana was confirmed. Furthermore, using transcriptome analysis, we compared A. koreana seedlings treated with Au. pullulans AK10 to untreated controls under drought conditions to elucidate the molecular responses involved in increased drought tolerance. Our findings revealed a predominance of downregulated genes in the treated seedlings, suggesting a strategic reallocation of resources to enhance stress defense. Further exploration of enriched Kyoto Encyclopedia of Genes and Genomes pathways and protein-protein interaction networks revealed significant alterations in functional systems known to fortify drought tolerance, including the terpenoid backbone biosynthesis, calcium signaling pathway, pyruvate metabolism, brassinosteroid biosynthesis, and, crucially, flavonoid biosynthesis, renowned for enhancing plant drought resistance. These findings deepen our comprehension of how AK10 biostimulation enhances the resilience of A. koreana to drought stress, marking a substantial advancement in the effort to conserve this endangered tree species through environmentally sustainable treatment.

Aureobasidium pullulans Treatment Mitigates Drought Stress in Abies koreana via Rhizosphere Microbiome Modulation

The Korean fir tree Abies koreana, an endangered species in Korea, faces threats primarily from climate change-induced stress and drought. This study proposed a sustainable method to enhance A. koreana drought tolerance using a black yeast-like fungus identified as Aureobasidium pullulans (AK10). The 16S/ITS metabarcoding analysis assessed the impact of drought and AK10 treatment on the seedlings' rhizosphere microbiome. Results revealed a profound drought influence on the microbiome, particularly affecting fungal mycobiota. Drought-stressed seedlings exhibited elevated Agaricaceae levels, opportunistic fungi generally associated with decomposition. AK10 treatment significantly mitigated this proliferation and increased the relative abundance of beneficial fungi like Cystofilobasidium and Mortierella, known biocontrol agents and phosphate solubilizers. A notable reduction in the phytopathogenic Fusarium levels was observed with AK10, alongside an increase in beneficial bacteria, including Azospirillum and Nitrospirillum. Furthermore, the conducted correlation analysis shed light on microbial interrelationships within the rhizosphere, elucidating potential co-associations and antagonisms. Taken together, the isolated A. pullulans AK10 identified in this study serves as a potential biostimulant, enhancing the drought tolerance in A. koreana through beneficial alterations in the rhizosphere microbiome. This approach presents a promising strategy for the conservation of this endangered species.

Triterpenoids from the leaves of Abies koreana and their biological activities

Seven undescribed triterpenoids, abikoranes A-G, along with three known triterpenoids were isolated from the leaves of Abies koreana E. H. Wilson. The structures of compounds were elucidated by 1D and 2D NMR, HRMS, ECD, specific rotation, and DP4+ analysis. Abikorane A represents the second example of nor-3,4-seco-17,14-friedo-lanostane triterpenoid. Among the isolates, some compounds showed strong cytotoxic activities against some of four tested cancer cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-116) with the values of IC₅₀ 0.89-9.62 μM, inhibited lipopolysaccharide-stimulated nitric oxide production with IC₅₀ values of 11.57-15.16 μM, and exhibited significant nerve growth factor release effect (192.54 ± 12.33%) from C6 glioma cells.

A nostoxanthin-producing bacterium, Sphingomonas nostoxanthinifaciens sp. nov., alleviates the salt stress of Arabidopsis seedlings by scavenging of reactive oxygen species

A novel, nostoxanthin-producing, endophytic bacterium, designated as AK-PDB1-5^T, was isolated from the needle-like leaves of the Korean fir (Abies koreana Wilson) collected from Mt. Halla in Jeju, South Korea. A 16S rRNA sequence comparison indicated that the closest phylogenetic neighbors were Sphingomonas crusticola MIMD3^T (95.6%) and Sphingomonas jatrophae S5-249^T (95.3%) of the family Sphingomonadaceae. Strain AK-PDB1-5^T had a genome size of 4,298,284 bp with a 67.8% G + C content, and digital DNA-DNA hybridization and OrthoANI values with the most closely related species of only 19.5-21% and 75.1-76.8%, respectively. Cells of the strain AK-PDB1-5^T were Gram-negative, short rods, oxidase- and catalase-positive. Growth occurred at pH 5.0-9.0 (optimum pH 8.0) in the absence of NaCl at 4-37°C (optimum 25-30°C). Strain AK-PDB1-5^T contained C_14:0 2OH_, C_16:0 and summed feature 8 as the major cellular fatty acids (> 10%), while sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, phospholipids and lipids were found to be the major polar lipids. The strain produces a yellow carotenoid pigment; natural products prediction via AntiSMASH tool found zeaxanthin biosynthesis clusters in the entire genome. Biophysical characterization by ultraviolet-visible absorption spectroscopy and ESI-MS studies confirmed the yellow pigment was nostoxanthin. In addition, strain AK-PDB1-5^T was found significantly promote Arabidopsis seedling growth under salt conditions by reducing reactive oxygen species (ROS). Based on the polyphasic taxonomic analysis results, strain AK-PDB1-5^T was determined to be a novel species in the genus Sphingomonas with the proposed name Sphingomonas nostoxanthinifaciens sp. nov. The type strain is AK-PDB1-5^T (= KCTC 82822^T = CCTCC AB 2021150^T).

Synergistic Antitumor Effect of 5-Fluorouracil Combined with Constituents from Pleurospermum lindleyanum in Hepatocellular Carcinoma SMMC-7721 Cells

BACKGROUND

A Chinese folk medicine plant Pleurospermum lindleyanum possesses pharmacological activities of heat-clearing, detoxifying and preventing from hepatopathy, coronary heart disease, hypertension, and high altitude sickness. We isolated and characterized its constituents to investigate its synergistic effects against human hepatoma SMMC-7721 cells.

OBJECTIVE

The aim of this study was to explore the synergistic anti-cancer activities of isolates from P. lindleyanum with 5-FU on hepatoma SMMC-7721 cells in vitro and their primary mechanisms.

METHODS

Sequential chromatographic techniques were conducted for the isolation studies. The isolate's structures were established by spectroscopic analysis as well as X-ray crystallographic diffraction. Growth inhibition was detected by MTT assay. The isobologram method was used to assess the effect of drug combinations. Flow cytometry and western blot were used to examine apoptosis and protein expression.

RESULTS

A new coumarin (16), along with sixteen known compounds, were isolated from the whole plant of P. lindleyanum and their structures were elucidated by spectroscopic methods. Four coumarins (2, 3, 5, and 16), two flavonoids (8 and 9) and three phytosterols and triterpenes (12-14) were found to synergistically enhance the inhibitory effect of 5-FU against SMMC-7721 cells. Among them, compounds 3 and 16 exhibited the best synergistic effects with IC50 of 5-FU reduced by 16-fold and 22-fold possessing the minimum Combination Index (CI) 0.34 and 0.27. The mechanism of action of combinations might be through synergistic arresting for the cell cycle at G1 phases and the induction of apoptosis. Moreover, western blotting and molecular docking revealed that compounds 3 or 5 might promote 5-FU-induced apoptosis by regulating the expression of Caspase 9 and PARP.

CONCLUSION

Constituents from P. lindleyanum may improve the treatment effectiveness of 5-FU against hepatocellular carcinoma cells.

Selective Cytotoxicity and Antioxidant Effects of Compounds from Dioscorea membranacea Rhizomes

Bioassay-guided isolation was used to separate the active ingredients of the ethanolic extract of Dioscorea membranacea by testing cytotoxic activity against three human cancer cell lines, i.e. large cell lung carcinoma (COR-L23), colon cell line (LS-174T) and breast cancer cell line (MCF-7), and two normal human cell lines, keratinocytes (SVK-14) and normal human fibroblasts (HF), using the SRB assay. The DPPH test for antioxidant activity was also employed, as was a test for LDH release as an indicator of damage to the cell membrane. Eight compounds were isolated, two naphthofuranoxepins (dioscorealides A [1] and B [2]), a 1,4-phenanthraquinone (dioscoreanone [3]), three steroids (β-sitosterol [4], stigmasterol [5] and β-D-sitosterol glucoside [8]) and two steroid saponins diosgenin-(3- O-α-L-rhamnopyranosyl (1→2)-β-D-glucopyranoside [6] and diosgenin 3- O-β-D-glucopyranosyl (1→3)-β-D-glucopyranoside [7]). Cytotoxic activity of 2, 3 and 6 was shown against three cancer cell lines, and 2 showed selective cytotoxic activity against lung and breast cancer, but was less active against the two normal cells, and was not toxic to cell membranes in the LDH assay. The highest antioxidant activity was shown by 3.

Influence of Binasal and Uninasal Inhalations of Essential Oil of Abies koreana Twigs on Electroencephalographic Activity of Human

Objectives. The present work investigates the effect of essential oil from the twigs of Abies koreana on electroencephalographic (EEG) activity of human brain in order to understand the influence of binasal and uninasal inhalations. Methods. To accomplish this study, the essential oil from the twigs of A. koreana (AEO) was isolated by steam distillation and the EEG readings were recorded using QEEG-8 system from 8 grounding electrodes according to the International 10-20 System. Results. D-Limonene (25.29%), bornyl acetate (19.31%), camphene (12.48%), α-pinene (11.88%), β-pinene (6.45%), and eudesm-7(11)-en-ol (5.38%) were the major components in the essential oil. In the EEG study, the absolute alpha (left frontal and right parietal) and absolute fast alpha (right parietal) values significantly increased during the binasal inhalation of AEO. In the uninasal inhalation, absolute beta and theta values decreased significantly, especially in the right frontal and left and right parietal regions. The results revealed that the AEO produced different EEG power spectrum changes according to the nostril difference. Conclusion. The changes in EEG values due to the inhalation of AEO may contribute to the enhancement of relaxation (binasal inhalation) and alertness/attention (right uninasal inhalation) states of brain which could be used in aromatherapy treatments.

Epimeric spirolactone-type triterpenoids from Abies faxoniana Rehd

Phytochemical investigation of Abies faxoniana Rehd. led to the isolation of two pairs of new epimeric spirolactone-type triterpenoids (1/1' and 2/2') and 11 known terpenoids (3-13). Compounds 1/1' and 2/2' were isolated as epimeric mixtures due to the C-23 ketal tautomerism in their spirolactone structures. The dynamic HPLC manifested that the C-23 epimeric mixtures interconverted into each other in solution. Structure determinations were based on extensive NMR and HRESIMS spectroscopic analysis. Meanwhile, their cytotoxic activities were tested by MTT method. Compound 5 showed cytotoxicities against MCF-7 and A549 cells with IC50 values of 6.5 and 5.7μM, respectively. Compounds 1/1' had IC50 values of 10.0 and 12.3μM for Huh7 and SMMC7721 cells, respectively.

Miscellaneous terpenoid constituents of Abies nephrolepis and their moderate cytotoxic activities

Three monoterpenoids and two triterpenoids were isolated from Abies nephrolepis together with 53 known terpenoids. The structures of the compounds were established by 1D and 2D NMR spectroscopy. The absolute configuration of 3-hydroxycamphane-2-carboxylic acid was established as (1S,2R,3S,4R) by Cu-Kα X-ray crystallography. All 58 isolates were tested for cytotoxic activity against four tumor cells viz. A549 (human lung adenocarcinoma), Colo205 (colon adenocarcinoma), QGY-7703 (human hepatoma) and THP-1 (human monocytic leukemia). α-Cadinol exhibited the best effects on A549, Colo205 and QGY-7703 with IC(50) values of 8.6, 8.1 and 4.6 μg/mL, respectively.

Abies koreana essential oil inhibits drug-resistant skin pathogen growth and LPS-induced inflammatory effects of murine macrophage

Since acne vulgaris is the combined result of a bacterial infection and the inflammatory response to that infection, we examined whether Abies koreana essential oil (AKE) possessed anti-inflammatory and antibacterial activities against skin pathogens. In this study, AKE showed excellent antibacterial activities against drug-susceptible and -resistant Propionibacterium acnes and Staphylococcus epidermidis, which are acne-causing bacteria. In addition, AKE reduced the LPS-induced secretion of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, NO and PGE(2) in RAW 264.7 cells, indicating that it has anti-inflammatory effects. Therefore, we suggest that AKE may be an attractive candidate for promoting skin health.

Anti-inflammatory and anti-tumour effects of Abies georgei extracts

Chloroform (AGC), ethyl acetate (AGE) and n-butanol (AGB) extracts of Abies georgei were investigated for anti-tumour and anti-inflammatory activities in-vitro and in-vivo. AGC exhibited potent antiproliferative effects against A549, LOVO, QGY-7703 and 6T-CEM tumour cells, with EC50 values of 77.5, 7.8, 11.1 and 32.8 microg mL(-1), respectively. It also inhibited the growth of S180 sarcoma implanted into mice; tumour growth inhibition ratios were 46.7, 53.1 and 31.0% of controls at doses of 100, 200 and 400 mgkg(-1), respectively. AGE showed significant anti-inflammatory activities in the carrageenin-induced acute pedal oedema model in rats and dimethylbenzene-induced ear oedema in mice at doses of 140 mgkg(-1) and 200 mgkg(-1) p.o., respectively. Primary mechanism studies in-vitro showed that AGE inhibited platelet aggregation induced in rabbits by arachidonic acid (AA), with an IC50 of 14.4 microg mL(-1). Its effect on AA metabolism was also studied in mouse peritoneal macrophages stimulated by A23187. Formation of prostaglandin E(2), leukotriene B(4) and 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) was significantly inhibited in a concentration-dependent manner. In addition, AGE inhibited lipopolysaccharide-induced nitric oxide production in RAW246.7 macrophages and nuclear factor kappaB activation induced in 293 cells by tumour necrosis factor alpha.

Chemical composition and antibacterial activities of the essential oil fromAbies koreana

The essential oils from an alpine needle leaf of Abies koreana, which is a species native to Korea, was obtained by hydrodistillation with 0.9% (v/w) yield and analysed by GC and GC-MS. Sixty-eight constituents, accounting for more than 95.9% of the total oil composition, were identified. The main compounds with concentrations higher than 3% were borneol (27.9%), alpha-pinene (23.2%), beta-pinene (5.8%), terpinene-4-ol (3.8%), bornyl acetate (3.4%) and alpha-terpineol (3.1%). The antibacterial activity of the oil was evaluated against nine microorganisms using disc diffusion and broth microdilution methods. The essential oil exhibited some broad spectrum antibacterial activity against the tested organisms, including methicillin-resistant Staphylococcus aureus.

Two lanostane triterpenoids from Abies koreana

Two lanostane-type triterpenoids, namely, 24(E)-3,4-seco-9betaH-lanosta-4(28),7,24-triene-3,26-dioic acid and 24(E)-3-oxo-9betaH-lanosta-7,24-dien-26-ol were isolated from the root bark of Abies koreana. Their structures were established based on spectroscopic analyses. Compound 2 exhibited marginal cytotoxicity against human tumor cell lines.

Phytochemical constituents of Cirsium setidens Nakai and their cytotoxicity against human cancer cell lines

Five terpenes (1-5), three fatty acids (6-8), two sterols (9 and 11), and a monogalactosyldiacyl glycerol (10) were isolated from the methylene chloride extract of the aerial part of Cirsium setidens. Their chemical structures were determined to be alpha-tocopherol (1), 25-hydroperoxycycloart-23-en-3beta-ol (2), 24-hydroperoxycycloart-25-en-3beta-ol (3), mokko lactone (4), transphytol (5), 9,12,15-octadecatrienoic acid (6), 9,12-octadecadienoic acid (7), hexadecanoic acid (8), acylglycosyl beta-sitosterol (9), (2R)-1,2-O-(9z,12z,15z-dioctadecatrienoyl)-3-O-beta-D-galactopyranosyl glycerol (10) and beta-sitosterol glucoside (11) by spectral evidences. Compound 3 exhibited significant cytotoxic activity against five human cancer cell lines with its ED50 values ranging from 2.66 to 11.25 microM.