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Planta medica [journal]
- Meroterpenes with Toll-Like Receptor 3 Regulating Activity from the Endophytic Fungus Guignardia mangiferae. [JOURNAL ARTICLE]
- Planta Med 2014 Dec 17.
The endophytic fungus Guignardia mangiferae isolated from Ilex cornuta leaves was shown to produce a family of meroterpenes with toll-like receptor 3 regulating activity (1-9), of which 1-3 possessed new structures. The absolute stereochemistry of 1-3 was assigned through a combination of nuclear magnetic resonance experiments, chemical derivation, CD spectra, and single-crystal X-ray diffraction analyses (CuK α ). The precursor labeled cultivation suggests that these meroterpenes are most likely assembled through terpenoid-shikimate pathways. Moreover, meroterpenes 1-3, 5-7, and 9 selectively upregulate, but 4 and 8 downregulate the toll-like receptor 3 expression in mouse dendritic cells at 10.0 µM.
- Modulation of Calcium Signaling of Angiotensin AT1, Endothelin ETA, and ETB Receptors by Silibinin, Quercetin, Crocin, Diallyl Sulfides, and Ginsenoside Rb1. [JOURNAL ARTICLE]
- Planta Med 2014 Dec 17.
Angiotensin II and endothelin-1 are potent vasoconstrictive peptides that play a central role in blood pressure regulation. Both peptides exert their pleiotropic effects via binding to their respective G-protein-coupled receptors, i.e., angiotensin AT1 and endothelin type A and type B receptors. In the present study, we have selected six structurally different plant-derived compounds with known cardioprotective properties to evaluate their ability to modulate calcium signaling of the above-mentioned receptors. For this purpose, we used and validated a cellular luminescence-based read-out system in which we measured intracellular calcium signaling in Chinese hamster ovary cells that express the calcium sensitive apo-aequorin protein. Firstly, silibinin, a flavanolignan that occurs in milk thistle (Silybum marianum), was investigated and found to be an antagonist for the human angiotensin AT1 receptor with an affinity constant of about 9 µM, while it had no effect on endothelin type A or type B receptor activation. Quercetin and crocin partially impeded intracellular calcium signaling resulting in a non-receptor-related reduction of the responses recorded for the three investigated G-protein-coupled receptors. Two organosulfur compounds, diallyl disulfide and diallyl trisulfide, as well as the triterpene saponin ginsenoside Rb1 did not affect the activation of the angiotensin AT1 and endothelin type A and type B receptors. In conclusion, we were able, by using a nonradioactive cellular read-out system, to identify a novel pharmacological property of the flavanolignan silibinin.
- HPLC Quantification of All Five Ginkgolic Acid Derivatives in Ginkgo biloba Extracts using 13 : 0 Ginkgolic Acid as a Single Marker Compound. [Journal Article]
- Planta Med 2015 Jan; 81(1):71-8.
An HPLC quantification method for ginkgolic acid derivatives in Ginkgo biloba leaf extracts was developed. Using 13 : 0 ginkgolic acid as a marker compound, the relative correlation factors of the four other ginkgolic acid derivatives - namely, 15 : 0 ginkgolic acid, 15 : 1 ginkgolic acid, 17 : 1 ginkgolic acid, and 17 : 2 ginkgolic acid - to 13 : 0 ginkgolic acid were determined by HPLC and subsequently used for calculating their contents in ten hydro-ethanolic refined extract samples. In other words, the content of 13 : 0 ginkgolic acid in the extracts was determined using the isolated compound as an external standard. Subsequently the now known concentration of this compound functioned as an internal standard for the quantification of the other four ginkgolic acid derivatives via the described correlation factors. This HPLC method was validated by two independent control measurements, one with an external standard for every individual compound and one based on the present method with the single marker compound alone. The results did not differ significantly in any of the 10 tested extract samples. The protocol presented here thus not only uses the same reference substance for G. biloba extracts as the current Chinese Pharmacopoeia method but also incorporates the advantages of the current European Pharmacopoeia approach. It is simple, reproducible, and can be used to determine the total contents of ginkgolic acid derivatives in G. biloba leaf extracts.
- Isolation and Identification of Twelve Metabolites of Isocorynoxeine in Rat Urine and their Neuroprotective Activities in HT22 Cell Assay. [Journal Article]
- Planta Med 2015 Jan; 81(1):46-55.
Isocorynoxeine, one of the major alkaloids from Uncaria Hook, shows the effects of lowering blood pressure, vasodilatation, and protection against ischemia-induced neuronal damage. In this paper, the metabolism of isocorynoxeine was investigated in rats. Twelve metabolites and the parent drug were isolated by using solvent extraction and repeated chromatographic methods, and determined by spectroscopic methods including UV, MS, NMR, and CD experiments. Seven new compounds were identified as 11-hydroxyisocorynoxeine, 5-oxoisocorynoxeinic acid-22-O-β-D-glucuronide, 10-hydroxyisocorynoxeine, 17-O-demethyl-16,17-dihydro-5-oxoisocorynoxeine, 5-oxoisocorynoxeinic acid, 21-hydroxy-5-oxoisocorynoxeine, and oxireno[18, 19]-5-oxoisocorynoxeine, together with six known compounds identified as isocorynoxeine, 18,19-dehydrocorynoxinic acid, 18,19-dehydrocorynoxinic acid B, corynoxeine, isocorynoxeine-N-oxide, and corynoxeine-N-oxide. Possible metabolic pathways of isocorynoxeine are proposed. Furthermore, the activity assay for the parent drug and some of its metabolites showed that isocorynoxeine exhibited a significant neuroprotective effect against glutamate-induced HT22 cell death at the maximum concentration. However, little or weak neuroprotective activities were observed for M-3, M-6, M-7, and M-10. Our present study is important to further understand their metabolic fate and disposition in humans.
- Bornyl Cinnamate Inhibits Inflammation-Associated Gene Expression in Macrophage Cells through Suppression of Nuclear Factor-κB Signaling Pathway. [Journal Article]
- Planta Med 2015 Jan; 81(1):39-45.
Formosan sweetgum (Liquidamber formosana) is an endemic tree species. Various parts of this tree are used as a traditional Chinese medicine for treating pain, inflammation, and rheumatic disorders. In this study, we investigated the anti-inflammatory potential of bornyl cinnamate, a cinnamic acid derivative from the essential oil of L. formosana. Pretreatment with bornyl cinnamate significantly inhibited lipopolysaccharide-induced proinflammatory molecules, including nitric oxide, prostaglandin-E2, tumor necrosis factor α, and interleukin-1β production, in murine macrophage RAW 264.7 cells. RT-PCR and immunoblotting analysis revealed that the inhibition of the proinflammatory molecules occurred through the downregulation of their corresponding mediator genes. Immunofluorescence and luciferase reporter assays revealed that the inhibition of proinflammatory genes by bornyl cinnamate was caused by the suppression of nuclear translocation and transcriptional activation of the redox-sensitive transcription factor nuclear factor κB. In addition, bornyl cinnamate increased the protein stability of the inhibitor of nuclear factor κB, an endogenous repressor of nuclear factor κB, through inhibition of its phosphorylation and proteasomal degradation. Furthermore, bornyl cinnamate significantly blocked the lipopolysaccharide-induced activation of I-κB kinase α, an upstream kinase of the inhibitor of nuclear factor κB α. Taken together, these results suggest that bornyl cinnamate could inhibit proinflammatory molecules through the suppression of the redox-sensitive nuclear factor κB signaling pathway.
- Antitumour Efficacy of Piper tuberculatum and Piplartine Based on the Hollow Fiber Assay. [Journal Article]
- Planta Med 2015 Jan; 81(1):15-9.
Piper tuberculatum, popularly known in Brazil as "jaborandi falso" and "pimenta darta", is widely used in folk medicine for the treatment of several diseases. In this study, the in vivo hollow fiber assay was used to investigate the antitumour efficacy of the crude extract and piplartine obtained from P. tuberculatum roots. Human glioblastoma (SF-295) and colon carcinoma (HCT-8) cell lines were used. In vitro cytotoxicity was assayed by the MTT assay. In the hollow fiber assay, nude mice implanted with tumour cells in hollow fibers were treated for four consecutive days via the intraperitoneal route, and tumour cell populations were assessed by the MTT assay. Both the crude extract and piplartine displayed cytotoxicity. In the hollow fiber assay, tumour growth inhibition rates were 24.6-54.8 % for the crude extract and 33.7-62.2 % for piplartine. No signal of toxicity was noticed. In conclusion, the crude extract and piplartine obtained from P. tuberculatum roots displayed in vitro and in vivo anticancer efficacy.
- Acknowledgement. [Journal Article]
- Planta Med 2015 Jan; 81(1):4-9.
- Editorial. [Journal Article]
- Planta Med 2015 Jan; 81(1):1.
- Simultaneous Determination of Twenty-Two Components in Asari Radix et Rhizoma by Ultra Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry. [Journal Article]
- Planta Med 2014 Dec; 80(18):1753-62.
Asari Radix et Rhizoma is a herbal medicine for the treatment of common cold, rhinitis, etc. An ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method has been established for the rapid analysis of 22 components in 27 samples from the raw materials of Asari Radix et Rhizoma and an adulterant. A total of 5 lignans, 5 essential oils, 3 aristolochic acids, 4 alkamides, and 5 flavanoids were identified by co-chromatography of samples extracts and comparison of the retention time, UV spectra, characteristic molecular ions, and fragment ions with those of authentic standards, or tentatively identified by MS/MS determination along with MassFragment software. Moreover, the method was validated for the simultaneous quantification and semi-quantification of 20 components. The samples from Asarum heterotropoides var. mandshuricum differed in the quantity of 2-methoxyl-4,5-methylenedioxypropiophenone and kakuol from those of Asarum sieboldii var. seoulense, and the chemical difference was supported by principal component analysis and orthogonal partial least squared discriminant analysis based on dataset obtained from UHPLC-QTOF/MS. In comparison with the samples from the two medicinal Asarum species mentioned above, those from A. himalaicum differed in the quality and quantity of major compounds and contained higher amounts of aristolochic acid I.