| 1. |
- Andersson Dunstan, Christina, et al.
(författare)
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Evaluation of some Samoan and Peruvian medicinal plants by prostaglandin biosynthesis and rat ear oedema assays
- 1997
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Ingår i: Journal of Ethnopharmacology. - 0378-8741 .- 1872-7573. ; 57:1, s. 35-56
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Tidskriftsartikel (refereegranskat)abstract
- In our ongoing program to find new anti-inflammatory compounds, 58 extracts from 46 different medicinal plant species, used in treatment of inflammatory disorders - 38 plants from the traditional medicine of Western Samoa and eight originating from the indigenous medicine of the Shipibo-Conibo tribe of Peruvian Amazonia - were evaluated. The ability of all extracts to inhibit cyclooxygenase-1 catalysed prostaglandin biosynthesis in vitro was examined. Of the plant species tested 14 showed moderate to strong inhibition; including 11 Samoan and three Peruvian species. Further, 12 Samoan and all eight Peruvian species were investigated on their inhibitory activity of ethyl phenylpropiolate induced rat ear oedema in vivo Significant activity was shown by 10 of the Samoan and by all eight Peruvian species. An additional evaluation of the most active species was provided through a compilation of existing literature documenting traditional medicinal uses, pharmacological activity and chemical constituents. Several known cyclooxygenase-l inhibitors were reported to which the observed pharmacological activity can be attributed at least partly. The combination of chemical and pharmacological literature data and our experimental data may help to explain the anti-inflammatory use of these species in indigenous medicine.
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| 2. |
- Bucar, Franz, et al.
(författare)
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Amentoflavone from Biophytum sensitivum and its effect on COX-1/COX-2 catalysed prostaglandin biosynthesis
- 1998
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Ingår i: Planta Medica. - : Thieme. - 0032-0943 .- 1439-0221. ; 64:4, s. 373-374
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Tidskriftsartikel (refereegranskat)abstract
- Amentoflavone (13′, ll8-biapigenin) was isolated from the roots of Biophytum sensitivum DC. (Oxalidaceae) and proved to be a selective inhibitor of cyclooxygenase (COX)-1 catalysed prostaglandin biosynthesis when tested in vitro with an IC50 value of 12.4 µM (standard: indomethacin, IC50 = 1.1 µM). Doses of up to 37 µM showed only a slight inhibition in the corresponding COX-2 assay. Quantification of amentoflavone was carried out by reversed phase HPLC in methanolic and aqueous extracts of the roots, stems and leaves. Highest amounts of amentoflavone were detected in methanolic extracts of roots and stems (0.26-0.35%), while considerably lower amounts were detected in the corresponding water extracts.
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| 3. |
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| 4. |
- Noreen, Ylva, et al.
(författare)
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Flavan-3-ols isolated from some medicinal plants inhibiting COX-1 and COX-2 catalysed prostaglandin biosynthesis
- 1998
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Ingår i: Planta Medica. - : Georg Thieme Verlag KG. - 0032-0943 .- 1439-0221. ; 64:6, s. 520-524
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Tidskriftsartikel (refereegranskat)abstract
- Extracts from the four plant species Atuna racemosa Raf. ssp. racemosa, Syzygium corynocarpum (A. Gray) C. Muell., Syzygium malaccense (L.) Merr. & Perry and Vantanea peruviana Macbr., traditionally used for inflammatory conditions, were fractionated using a cyclooxygenase-1 catalysed prostaglandin biosynthesis in vitro assay. The flavan-3-ol derivatives (+)-catechin, (+)-gallocatechin, 4'-O-Me-ent-gallocatechin, ouratea-catechin and ouratea-proanthocynidin A were isolated as active principles. The IC50 values ranged from 3.3 mu M to 138 mu M whilst indomethacin under the same test conditions had an IC50 value of 1.1 mu M. The flavonol rhamnosides mearnsitrin, myricitrin and quercitrin were also isolated. When further tested for inhibitory effect on cyclooxygenase-2 catalysed prostaglandin biosynthesis, the five flavan-3-ol derivatives exhibited from equal to weaker inhibitory potencies, as compared to their cyclooxygenase-l inhibitory effects. The flavonol rhamnosides were inactive towards both enzymes.
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| 5. |
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| 6. |
- Noreen, Ylva, et al.
(författare)
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Two new isoflavones from Ceiba pentandra and their effect on cyclooxygenase-catalyzed prostaglandin biosynthesis
- 1998
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Ingår i: Journal of natural products (Print). - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 61:1, s. 8-12
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Tidskriftsartikel (refereegranskat)abstract
- The new isoflavone glucoside vavain 3'-O-beta-d-glucoside (1) and its aglycon, vavain (2), were isolated from the bark of Ceiba pentandra, together with the known flavan-3-ol, (+)-catechin, These novel structures were elucidated by one- and two-dimensional NMR experiments and by MS, IR, and UV spectroscopy as 5-hydroxy-7,4',5'-trimethoxyisoflavone 3'-O-beta-D-glucoside (1) and 5,3'-dihydroxy-7,4',5'-trimethoxyisoflavone (2), respectively. The compounds were isolated following bioactivity-directed fractionation, using a cyclooxygenase-1-catalyzed prostaglandin biosynthesis assay in vitro, in which compounds 1 and 2 and (+)-catechin exhibited IC50 values of 381, 97, and 80 microM, respectively (standard: indomethacin, IC50 1,1 microM). When further tested for their inhibitory effects on cyclooxygenase-2-catalyzed prostaglandin biosynthesis, 1 and 2 were found to be inactive (IC50 > 1200 and > 900 microM, respectively).
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| 7. |
- Ringbom, Therese, et al.
(författare)
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Ursolic acid from Plantago major, a selective inhibitor of cyclooxygenase-2 catalyzed prostaglandin biosynthesis
- 1998
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Ingår i: Journal of natural products (Print). - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 61:10, s. 1212-1215
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Tidskriftsartikel (refereegranskat)abstract
- A hexane extract of Plantago major was investigated by bioactivity-directed fractionation, using an in vitro cyclooxygenase-2 (COX-2) catalyzed prostaglandin biosynthesis inhibition assay, and resulted in the isolation of ursolic acid (1). This triterpenoid showed a significant COX-2 inhibitory effect, directly on the enzyme activity, with an IC50 value of 130 microM and a COX-2/COX-1 selectivity ratio of 0.6. The structural isomer oleanolic acid (2) was found to be less active than 1, with an IC50 value of 295 microM, but showed a similar selectivity ratio (0.8). Furthermore, no significant inhibition on COX-2 or COX-1 was observed by the triterpenoid, 18beta-glycyrrhetinic acid (3). The direct inhibitory effect of 1 and 2 on COX-2 catalyzed prostaglandin biosynthesis increased with preincubation, indicating a time-dependent inhibition, while the effect on COX-1 was found to be independent of preincubation time.
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