Transmembrane G protein-coupled receptor 5 signaling stimulates fibroblast growth factor 21 expression concomitant with up-regulation of the transcription factor nuclear receptor Nr4a1.

Fibroblast growth factor 21 (FGF21) acts as an endocrine factor, playing important roles in the regulation of energy homeostasis, glucose and lipid metabolism. It is induced by diverse metabolic and cellular stresses, such as starvation and cold challenge, which in turn facilitate adaptation to the stress environment. The pharmacological action of FGF21 has received much attention, because the administration of FGF21 or its analogs has been shown to have an anti-obesity effect in rodent models. In the present study, we found that 3-O-acetyloleanolic acid, an active constituent isolated from the fruits of Forsythia suspensa, stimulated FGF21 production concomitant with the up-regulation of a transcription factor, nuclear receptor Nr4a1, in C2C12 myotubes. Additionally, significant increases in mFgf21 promoter activity were observed in C2C12 cells overexpressing TGR5 receptor in response to 3-O-acetyloleanolic acid treatment. Treatment with the p38 MAPK inhibitor SB203580 was effective at suppressing these stimulatory effects of 3-O-acetyloleanolic acid. Pretreatment with SB203580 also significantly repressed FGF21 mRNA abundance and FGF21 secretion in C2C12 myotubes after 3-O-acetyloleanolic acid stimulation, suggesting that p38 activation is required for the induction of FGF21 by ligand-activated TGR5 in C2C12 myotubes. These findings collectively indicated that TGR5 receptor signaling drives FGF21 expression via p38 activation, at least partly, by mediating Nr4a1 expression. Thus, the novel biological function of 3-O-acetyloleanolic acid as an agent having anti-obesity effects is likely to be mediated through the activation of TGR5 receptors.

3-O-Acetyloleanolic acid inhibits angiopoietin-1-induced angiogenesis and lymphangiogenesis via suppression of angiopoietin-1/Tie-2 signaling.

Tumor angiogenesis and lymphangiogenesis are important processes in tumor progression and metastasis. The inhibitory effects of 3-O-acetyloleanolic acid (3AOA), a pentacyclic triterpenoid compound isolated from Vigna sinensis K., on tumor-induced angiogenesis and lymphangiogenesis in vitro and in vivo were studied. Angiopoietin-1 is an important angiogenic and lymphangiogenic factor secreted from colon carcinoma CT-26 cells under hypoxia conditions. 3AOA inhibited proliferation, migration, and tube formation of angiopoietin-1-treated human umbilical vein endothelial cells (HUVEC) and human lymphatic microvascular endothelial cells (HLMEC). 3AOA reduced angiogenesis and lymphangiogenesis in angiopoietin-1-stimulated Matrigel plugs. Also, 3AOA inhibited tumor growth and tumor-induced angiogenesis and lymphangiogenesis in an angiopoietin-1-induced CT-26 allograft colon carcinoma animal model. 3AOA inhibited activation of the angiopoietin-1 receptor Tie-2 and activation of the downstream signaling factors FAK, AKT, and ERK1/2 that are involved in the angiopoietin-1/Tie-2-signaling pathway. Thus, 3AOA has an inhibitory effect on angiogenesis and lymphangiogenesis induced by angiopoietin-1 both in vitro and in vivo, and the inhibitory effect of 3AOA is probably due to suppression of angiopoietin-1/Tie-2 signaling in HUVEC and HLMEC.

3-O-Acetyloleanolic acid inhibits VEGF-A-induced lymphangiogenesis and lymph node metastasis in an oral cancer sentinel lymph node animal model.

BACKGROUND: Sentinel lymph node metastasis is a common and early event in the metastatic process of head and neck squamous cell carcinoma (HNSCC) and is the most powerful prognostic factor for survival of HNSCC patients. 3-O-acetyloleanolic acid (3AOA), a pentacyclic triterpenoid compound isolated from seeds of Vigna sinensis K., has been reported to have potent anti-angiogenesis and anti-tumor activities. However, its effects on tumor-related lymphangiogenesis and lymph node metastasis are not yet understood. METHODS: The in vitro inhibitory effects of 3AOA on VEGF-A-induced lymphangiogenesis were investigated via in vitro experiments using mouse oral squamous cell carcinoma (SCCVII) cells and human lymphatic microvascular endothelial cells (HLMECs). The in vivo inhibitory effects of 3AOA on VEGF-A-induced lymphangiogenesis and sentinel lymph node metastasis were investigated in an oral cancer sentinel lymph node (OCSLN) animal model. RESULTS: 3AOA inhibited tumor-induced lymphangiogenesis and sentinel lymph node metastasis in an OCSLN animal model, and reduced expression of VEGF-A, a lymphangiogenic factor in hypoxia mimetic agent CoCl2-treated SCCVII cells. 3AOA inhibited proliferation, tube formation, and migration of VEGF-A-treated HLMECs. The lymphatic vessel formation that was stimulated in vivo in a by VEGF-A Matrigel plug was reduced by 3AOA. 3AOA suppressed phosphorylation of vascular endothelial growth factor (VEGFR) -1 and - 2 receptors that was stimulated by VEGF-A. In addition, 3AOA suppressed phosphorylation of the lymphangiogenesis-related downstream signaling factors PI3K, FAK, AKT, and ERK1/2. 3AOA inhibited tumor growth, tumor-induced lymphangiogenesis, and sentinel lymph node metastasis in a VEGF-A-induced OCSLN animal model that was established using VEGF-A overexpressing SCCVII cells. CONCLUSION: 3AOA inhibits VEGF-A-induced lymphangiogenesis and sentinel lymph node metastasis both in vitro and in vivo. The anti-lymphangiogenic effects of 3AOA are probably mediated via suppression of VEGF-A/VEGFR-1 and VEGFR-2 signaling in HLMECs, and can be a useful anti-tumor agent to restrict the metastatic spread of oral cancer.

Simultaneous determination of 3-O-acetyloleanolic acid and oleanolic acid in rat plasma using liquid chromatography coupled to tandem mass spectrometry.

3-O-Acetyloleanolic acid (OAA) is a triterpenoid compound, and exerts an apoptosis in cancer cell lines, an inhibition of both atopic and allergic contact dermatitis in murine model, and a suppression of inflammatory bone loss in mice. OAA can be converted into oleanolic acid (OA) by hydrolysis in vivo, and OA exhibits several pharmacological effects as well. A liquid chromatographic method using tandem mass spectrometry (MS/MS) was developed for the simultaneous determination of OAA and OA in rat plasma. After liquid-liquid extraction with ethylacetate, both substances were chromatographed on a reversed phase column with a mobile phase of 0.1% formic acid aqueous solution and acetonitrile (1:9, v/v). The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of both substances over time following an intravenous administration of OAA in rats.

Chemical constituents of Lonicera japonica roots and anti-inflammatory activity / 中草药

Objective: To research the chemical composition from the roots of Lonicera japonica and their anti-inflammatory activities. Methods: The compounds were isolated and purified by chromatography on silica gel column, Sephadex LH-20 column, preparative thin-layer, and semi-preparative HPLC, etc. Their structures were identified on the basis of spectroscopic data, and parts of the isolated compounds were tested for their anti-inflammatory activities against zebrafish. Results: Fourteen compounds were isolated and elucidated as 3,13-dihydroxystemodan-2-one (1), chrysophanol (2), palmarumycin CP2 (3), β-sitosterol (4), stigmasterol (5), stigmast-4,6,8(14), 22-tetraen-3-one (6), erythrinassinate D (7), lanosterin (8), 3-O-acetyloleanolic acid (9), protocatechuin aldehyde (10), daucosterol (11), (E)-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)-2(3H)-furanone (12), lomacarinoside B (13), and (2E,6S)-8-(α-L-arabinopyranosyl-(1″→6')-β-D-glucopyranosyloxy)-2,6-dimethyloct-2-eno-1,2″-lactone (14). Conclusion: Compound 1 is a new compound, and compounds 2, 3, 6, 7-9, and 13 are isolated from L. japonica for the first time. Compounds 9 and 10 show the significant anti-inflammatory activities at 100 μg/mL.

Low-polarity chemical constituents from Scrophularia dentata grown in Tibet / 中草药

Objective: To study the low-polarity chemical constituents from the whole plants of Scrophularia dentata grown in Tibet. Methods: The compounds were isolated and purified by various column chromatography. Their structures were elucidated by means of spectral analyses (MS, 1H-NMR, and 13C-NMR). Results: Fifteen compounds were isolated and identified as oleanolic acid (1), 3-O-acetyloleanolic acid (2), stigmast-4-en-3-one (3), stigmast-4, 22-dien-3-one (4), 2, 6-dimethoxybenzoquinone (5), cerevisterol (6), cinnamic acid (7), spinasterol (8), β-sitosterol (9), 2-tritriacontanone (10), 2-(4-hydroxyphen-yl)-ethyl 1-dodecyloctadecanoate (11), apigenin (12), chrysoeriol (13), medioresinol (14), and syringaresinol (15). Conclusion: All the compounds are firstly isolated from this plant and compounds 2-6 and 10-15 are isolated from the plants of this genus for the first time.