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Alkaloid Isolated (alkaloid + isolated)
Selected AbstractsAntifibrotic effects of tetrandrine on hepatic stellate cells and rats with liver fibrosisJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 1 2007Yi-Chao Hsu Abstract Background:, Anti-inflammation strategies are one of the proposed therapeutic approaches to hepatic fibrosis. Tetrandrine (C38H42O8N2, molecular weight: 622; Tet), an alkaloid isolated from the Chinese medicinal herb Stephania tetrandra, has been shown to exert anti-inflammatory activity in pulmonary diseases. The purpose of the present study was to investigate the in vitro and in vivo effects of Tet on hepatic fibrosis. Methods:, A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with transforming growth factor-,1 (TGF-,1) or tumor necrosis factor-, (TNF-,). The inhibitory effects of Tet on the nuclear factor ,B (NF,B) signaling cascade and molecular markers including intercellular adhesion molecule-1 (ICAM-1) and ,-smooth muscle actin (,-SMA) secretion were assessed. Fibrosis was induced by dimethylnitrosamine (DMN) administration in rats for 4 weeks. Fibrotic rats were randomly assigned to one of the four groups: vehicle (0.7% carboxyl methyl cellulose, CMC), Tet (1 mg/kg), Tet (5 mg/kg), or silymarin (50 mg/kg), each given by gavage twice daily for 3 weeks starting after 1 week of DMN administration. At the end of the study, liver tissues were scored for fibrosis and analyzed for molecular markers of fibrosis. Results:, Tetrandrine (0.5,5.0 µmol/L) concentration-dependently inhibited NF,B transcriptional activity induced by TNF-,, including I,B, phosphorylation and mRNA expressions of ICAM-1 in HSC-T6 cells. In addition, Tet also inhibited TGF-,1-induced ,-SMA secretion and collagen deposition in HSC-T6 cells. Fibrosis scores of livers from DMN-treated rats with high-dose Tet (1.3 ± 0.3) were significantly reduced in comparison with DMN-treated rats receiving saline (2.0 ± 0.2). Hepatic collagen content of DMN rats was significantly reduced by either Tet or silymarin treatment. Double-staining results showed that ,-SMA- and NF,B-positive cells were decreased in the fibrotic livers by Tet and silymarin treatment. In addition, mRNA expression of ICAM-1, ,-SMA, and TGF-,1 was attenuated by Tet treatment. Moreover, levels of plasma aspartate aminotransferase and alanine aminotransferase activities were reduced by Tet and silymarin treatment. Conclusion:, Tetrandrine exerts antifibrotic effects in both HSC-T6 cells and in rats with DMN-induced fibrosis. [source] Studies on search for bioactive natural products targeting TRAIL signaling leading to tumor cell apoptosisMEDICINAL RESEARCH REVIEWS, Issue 5 2008Masami Ishibashi Abstract Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many transformed cells but not in normal cells and, hence, has been expected as a new anticancer strategy. During our studies on search for bioactive natural products from various natural resources such as plants and microorganisms, we recently identified several natural products which exhibited activities related to TRAIL signaling. Dimeric sesquiterpenoids isolated from Zingiberaceous plant, Curcuma parviflora, showed enhancement activity of gene expression of TRAIL-receptor and TRAIL-receptor protein level. Several new isoflavone natural products, named brandisianins, were isolated from Leguminosaeous plant, Millettia brandisiana, by our screening study targeting TRAIL-receptor expression enhancement activity. A dihydroflavonol (BB1) that was extracted from Compositaeous plant, Blumea balsamifera, and fuligocandin B, a new anthranilylproline-indole alkaloid isolated from myxomycete were found to exhibit reversal effect of TRAIL resistance activity. © 2008 Wiley Periodicals, Inc. Med Res Rev, 28, No. 5, 688,714, 2008 [source] Cyclic Adenosine Monophosphate Inhibits Quinolone Alkaloid Evocarpine-Induced Apoptosis via Activation of Protein Kinase A in Human Leukaemic HL-60 CellsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2000Na-Young Kim Evocarpine, an isoquinolone alkaloid isolated from the fruit of Evodia rutaecarpa, was found to induce apoptotic cell death in promyelocytic leukaemia HL-60 cells in dose- and time-dependent manners. We investigated the involvement of protein kinase A during the evocarpine-induced apoptotic cell death. Evocarpine-induced apoptosis was markedly inhibited by treatment of the cells with dibutyryl-cyclic adenosine monophosphate. Similar results were obtained with other commonly used cyclic adenosine monophosphate analogues, chlorophenylthio-cyclic adenosine monophosphate and the intracellular cyclic adenosine monophosphate-elevating agent, forskolin. In contrast, pretreatment of HL-60 cells with KT5720, an inhibitor of cyclic adenosine monophosphate-dependent protein kinase A, abrogated the protective effects of cyclic adenosine monophosphate analogues and forskolin on evocrpine-induced apoptosis. These findings suggest that cyclic adenosine monophosphate-dependent activation of protein kinase A plays a crucial role in protecting HL-60 cells from the evocarpine-induced apoptotic cell death. [source] Acetylcholinesterase inhibitors from Stephania venosa tuberJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 5 2006Kornkanok Ingkaninan Acetylcholinesterase (AChE) inhibitors have lately gained interest as potential drugs in the treatment of Alzheimer's disease. Three AChE inhibitors were isolated from tubers of a Thai medicinal plant, Stephania venosa (Bl) Spreng. They were identified as quaternary protoberberine alkaloids, stepharanine, cyclanoline and N -methyl stepholidine. They expressed inhibitory activity on AChE with IC50 values (concentration that caused 50% inhibition of activity) of 14.1K ± 0.81, 9.23 ± 3.47 and 31.30 ± 3.67 ,M, respectively. The AChE inhibitory activity of these compounds was compared with those of the related compounds, palmatine, jatrorrhizine and berberine, as well as tertiary protoberberine alkaloids isolated from the same plant, stepholidine and corydalmine. The results suggest that the positive charge at the nitrogen of the tetrahydroisoquinoline portion, steric substitution at the nitrogen, planarity of the molecule or substitutions at C-2, ,3, ,9, and ,10 affect the AChE inhibitory activity of protoberberine alkaloids. [source] Structure elucidation and NMR assignments of two new pyrrolidinyl quinoline alkaloids from chestnut honeyMAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2009Giangiacomo Beretta Abstract The complete 1H, 13C and 15N NMR spectral assignments of two new alkaloids isolated from chestnut honey and structurally related to kynurenic acid have been made using 1-D and 2-D NMR techniques, including COSY, HMQC and HMBC experiments. The new compounds have been identified as 3-(2,-pyrrolidinyl)-kynurenic acid and its ,-lactam derivative. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||