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Acer tegmentosum, a deciduous tree belonging to Aceraceae, has been used in traditional oriental medicine for treating hepatic disorders, such as hepatitis, cirrhosis, and liver cancer. We evaluated the estrogen-like effects of A. tegmentosum using an estrogen receptor (ER)-positive breast cancer cell line, namely MCF-7, to identify potential phytoestrogens and found that an aqueous extract of A. tegmentosum promoted cell proliferation in MCF-7 cells. Five phenolic compounds (1–5) were separated and identified from the active fraction using bioassay-guided fractionation of crude A. tegmentosum extract and phytochemical analysis. The chemical structures of the compounds were characterized as vanillic acid (1), 4-hydroxy-benzoic acid (2), syringic acid (3), isoscopoletin (4), and (E)-ferulic acid (5) based on the analysis of their nuclear magnetic resonance spectra and liquid chromatography-mass spectrometry data. All five compounds were evaluated using an E-screen assay for their estrogen-like effects on MCF-7 cells. Among the tested compounds, only 4-hydroxy-benzoic acid (2) promoted the proliferation of MCF-7 cells, which was mitigated by the ER antagonist, ICI 182,780. The mechanism underlying the estrogen-like effect of 4-hydroxy-benzoic acid (2) was evaluated via western blotting analysis to determine the expression levels of extracellular signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K), serine/threonine kinase (AKT), and ERα. Our results demonstrated that 4-hydroxy-benzoic acid (2) induced the increase in the protein expression levels of p-ERK, p-AKT, p-PI3K, and p-Erα, concentration dependently. Collectively, these experimental results suggest that 4-hydroxy-benzoic acid (2) is responsible for the estrogen-like effects of A. tegmentosum and may potentially aid in the control of estrogenic effects during menopause. [ABSTRACT FROM AUTHOR]

Extraction from edible plants is a highly important process that has various biological functions. To maximize biological activity, extraction methods should facilitate optimal extraction of functional phytochemicals. In this study, the optimal hydrothermal extraction conditions of Acer tegmentosum were determined using response surface methodology (RSM), and HepG2 cells were treated with optimized extract and hydrogen peroxide. In a central composition design, the independent variables were extraction temperature (X1: 70–90 °C), extraction time (X2: 2–6 h), and solvent-to-solid ratio (X3: 50–150). The maximum total phenolic contents (276.70 ± 10.11 mg GAE/g) and DPPH (2,2-diphenyl-1-pictylhydrazyl) activity (33.45 ± 2.20%) of A. tegmentosum were estimated at optimized extraction conditions, as follows: X1: 89.34 °C, X2: 7.36 h, X3: 184.09. Using the calculated extraction conditions, functional phytochemicals were extracted by hydrothermal extraction and freeze-dried. A. tegmentosum treatment (>10 μg/mL) of HepG2 cells remarkably attenuated hydrogen-peroxide-inducible hepatic cellular death and reactive oxygen species production in vitro. [ABSTRACT FROM AUTHOR]

Acer tegmentosum (ATM) has antioxidant and anti-adipogenic activity. However, few studies have investigated the pharmacological activity or mechanism of ATM as an antidepressant agent. We assessed the antidepressant effect of ATM in modulating menopausal depressive symptoms and its mechanisms in ovariectomized (OVX) and repeatedly stressed (RS) female rats. The female rats were randomly divided into four groups: (1) naïve normal (normal) group, (2) OVX + repeated stress + saline-treated (control) group, (3) OVX + repeated stress + ATM (100 mg•kg−1)-treated (ATM100) group and (4) OVX + repeated stress + ATM (400 mg•kg−1)-treated (ATM400) group. We performed a battery of tests, such as the forced swimming test (FST), the sucrose intake test, and social exploration. After behavior testing, serum corticosterone levels were examined, followed by immunohistochemical determination of c-Fos, tyrosine hydroxylase (TH), and interleukin-1 beta (IL-1β) expression in the brain. ATM administration was associated with significantly decreased immobility time in the FST. Also, the control group tended to have decreased sucrose intake and social exploration compared with the normal group. However, ATM treatment was associated with markedly increased sucrose intake and active social exploration. In the paraventricular nucleus, c-Fos and IL-1β expression were significantly decreased in the ATM400 group compared with the control group. Compared with the control group, high-dose ATM administration was also associated with markedly decreased expression of TH-immunoreactive neurons in the locus coeruleus. The study findings demonstrated that ATM treatment effectively decreased behavioral and pathophysiological depression-like responses. [ABSTRACT FROM AUTHOR]

Determination of bioactive chemicals in Acer tegmentosum is essential for its industrial application. Twelve phenolic compounds were isolated from A. tegmentosum. Specific seven compounds in the plant were simultaneously analyzed by high performance liquid chromatography- UV. The content of bioactive chemicals in the branch extract was determined to be 3.38 mg/g of (−)-epigallocatechin, 66.95 mg/g of salidroside, 39.61 mg/g of tyrosol, 17.04 mg/g of catechin, 7.39 mg/g of 1,2,4-tri- O-galloyl-β- d-glucose, 8.88 mg/g of 6- O-galloylsalidroside, and 4.61 mg/g of scopoletin. The method was validated with linearity ( R2 > 0.9947), as well as intra- and inter-day precision (0.07-2.77%) and accuracy (>97.0%). This analytical method is expected to be applied for standardization of dietary food containing A. tegmentosum. [ABSTRACT FROM AUTHOR]

The stem of Acer tegmentosum has been widely used in Korea for the treatment of hepatic disorders. In this study, we investigated the bone protective effect of water extract of the stem of Acer tegmentosum (WEAT). We found that WEAT inhibits osteoclast differentiation induced by receptor activator of nuclear factor-κB ligand (RANKL), an essential cytokine for osteoclast differentiation. In osteoclast precursor cells, WEAT inhibited RANKL-induced activation of JNK, NF-κB, and cAMP response element-binding protein, leading to suppression of the induction of c-Fos and nuclear factor of activated T cells cytoplasmic 1, key transcription factors for osteoclast differentiation. In addition, WEAT inhibited bone resorbing activity of mature osteoclasts. Furthermore, the oral administration of WEAT reduced RANKL-induced bone resorption and trabecular bone loss in mice. Taken together, our study demonstrates that WEAT possesses a protective effect on bone destruction by inhibiting osteoclast differentiation and function. [ABSTRACT FROM AUTHOR]

The chromatographic separation of the MeOH extract from the twigs of Acer tegmentosum led to the isolation of ten phenolic compounds. The structures of these compounds were determined using spectroscopic methods as 3,7,3′,4′-tetramethyl-quercetin ( 1), 5,3′-dihydroxy-3,7,4′-trimethoxy flavone ( 2), 2,6-dimethoxy- p-hydroquinone ( 3), (-)-catechin ( 4), morin-3-O-α-L-lyxoside ( 5), p-hydroxy phenylethyl-O-ß-D-glucopyranoside ( 6), 3,5-dimethoxy-4-hydroxy phenyl-1- O-ß-D-glucoside ( 7), fraxin, ( 8), 3,5-dimethoxy-benzyl alcohol 4- O-ß-D-glucopyrano-side ( 9) and 4-(2,3-dihydroxy propyl)-2,6-dimethoxy phenyl ß-D-glucopyranoside ( 10). The compounds were examined for their cytotoxic activity against five cancer cell lines. Compound 3 exhibited good cytotoxic activity against five human cancer cell lines with ED50 values ranging from 1.32 to 3.85 μM. [ABSTRACT FROM AUTHOR]

Methanol extracts of domestic plants of Korea were evaluated as a potential inhibitor of neutral pH optimum and membrane-associated 60 kDa sphingomyelinase ( N-SMase) activity. In this study, we partially purified N-SMase from bovine brain membranes using ammonium sulfate. It was purified approximately 163-fold by the sequential use of DE52, Butyl-Toyopearl, DEAE-Cellulose, and Phenyl-5PW column chromatographies. The purified N-SMase activity was assayed in the presence of the plant extracts of three hundreds species. Based on the in vitro assay, three plant extracts significantly inhibited the N-SMase activity in a time- and concentration-dependent manner. To further examine the inhibitory pattern, a Dixon plot was constructed for each of the plant extracts. The extracts of Abies nephrolepis, Acer tegmentosum, and Ginkgo biloba revealed a competitive inhibition with the inhibition constant (K i) of 11.9 μg/mL, 9.4 μg/mL, and 12.9 μg/mL, respectively. These extracts also inhibited in a dose-dependent manner the production of ceramide induced by serum deprivation in human neuroblastoma cell line SH-SY5Y. [ABSTRACT FROM AUTHOR]

The aim of the present study was to sequence and analyze the complete plastid genome (i.e. plastome) of Acer tegmentosum Maxim. The plastome of A. tegmentosum was 156,435 bp in length and included both large (86,265 bp) and small (18,102 bp) single-copy regions, which were separated by a pair of identical inverted repeats (26,034 bp). The plastome contained 77 unique protein-coding genes, 30 tRNA genes, and four rRNA genes. In addition, the gene order and organization of the A. tegmentosum plastome were consistent with those of plastomes from other members of the Sapindaceae, and the overall GC content of the plastome was 37.8%. A phylogenetic tree that was based on 76 protein-coding genes demonstrated a sister relationship within genus Acer. [ABSTRACT FROM AUTHOR]

In our ongoing research to discover natural products with neuroprotective effects, hyperoside (quercetin 3-O-galactoside) was isolated from Acer tegmentosum, which has been used in Korean traditional medicine to treat liver-related disorders. Here, we demonstrated that hyperoside protects cultured dopaminergic neurons from death via reactive oxygen species (ROS)-dependent mechanisms, although other relevant mechanisms of hyperoside activity remain largely uncharacterized. For the first time, we investigated the neuroprotective effects of hyperoside on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in neurons, and the possible underlying mechanisms. Hyperoside significantly ameliorated the loss of neuronal cell viability, lactate dehydrogenase release, excessive ROS accumulation and mitochondrial membrane potential dysfunction associated with 6-OHDA-induced neurotoxicity. Furthermore, hyperoside treatment activated the nuclear erythroid 2-related factor 2 (Nrf2), an upstream molecule of heme oxygenase-1 (HO-1). Hyperoside also induced the expression of HO-1, an antioxidant response gene. Remarkably, we found that the neuroprotective effects of hyperoside were weakened by an Nrf2 small interfering RNA, which blocked the ability of hyperoside to inhibit neuronal death, indicating the vital role of HO-1. Overall, we show that hyperoside, via the induction of Nrf2-dependent HO-1 activation, suppresses neuronal death caused by 6-OHDA-induced oxidative stress. Moreover, Nrf2-dependent HO-1 signaling activation represents a potential preventive and therapeutic target in Parkinson′s disease management. [ABSTRACT FROM AUTHOR]

Phytoestrogens derived from plants have attracted the attention of the general public and the medical community due to their potentially beneficial role in relieving menopausal symptoms. The deciduous tree Acer tegmentosum Maxim (Aceraceae) has long been utilized in Korean folk medicine to alleviate many physiological disorders, including abscesses, surgical bleeding, and liver diseases. In order to explore structurally and/or biologically new constituents from Korean medicinal plants, a comprehensive phytochemical study was carried out on the bark of A. tegmentosum. One new phenolic compound with a 1,4-benzodioxane scaffold, isoamericanoic acid B (1), as well as with nine known phenolic compounds (2–10), were successfully isolated from the aqueous extracts of the bark of A. tegmentosum. A detailed analysis using 1D and 2D NMR spectroscopy, electronic circular dichroism (ECD) spectral data, and LC/MS afforded the unambiguous structural determination of all isolated compounds, including the new compound 1. In addition, compounds 2, 4, 5, and 9 were isolated and identified from the bark of A. tegmentosum for the first time. All isolated compounds were tested for their estrogenic activities using an MCF-7 BUS cell proliferation assay, which revealed that compounds 1, 2, and 10 showed moderate estrogenic activity. To study the mechanism of this estrogenic effect, a docking simulation of compound 1, which showed the best estrogenic activity, was conducted with estrogen receptor (ER) -α and ER-β, which revealed that it interacts with the key residues of ER-α and ER-β. In addition, compound 1 had slightly higher affinity for ER-β than ER-α in the calculated Gibbs free energy for 1:ER-α and 1:ER-β. Thus, the present experimental evidence demonstrated that active compound 1 from A. tegmentosum could be a promising phytoestrogen for the development of natural estrogen supplements. [ABSTRACT FROM AUTHOR]