Neuroprotection and enhanced neurogenesis by extract from the tropical plant Knema laurina after inflammatory damage in living brain tissue.

Inflammatory reactions in the CNS, resulting from a loss of control and involving a network of non-neuronal and neuronal cells, are major contributors to the onset and progress of several major neurodegenerative diseases. Therapeutic strategies should therefore keep or restore the well-controlled and finely-tuned balance of immune reactions, and protect neurons from inflammatory damage. In our study, we selected plants of the Malaysian rain forest by an ethnobotanic survey, and investigated them in cell-based-assay-systems and in living brain tissue cultures in order to identify anti-inflammatory and neuroprotective effects. We found that alcoholic extracts from the tropical plant Knema laurina (Black wild nutmeg) exhibited highly anti-inflammatory and neuroprotective effects in cell culture experiments, reduced NO- and IL-6-release from activated microglia cells dose-dependently, and protected living brain tissue from microglia-mediated inflammatory damage at a concentration of 30 microg/ml. On the intracellular level, the extract inhibited ERK-1/2-phosphorylation, IkB-phosphorylation and subsequently NF-kB-translocation in microglia cells. K. laurina belongs to the family of Myristicaceae, which have been used for centuries for treatment of digestive and inflammatory diseases and is also a major food plant of the Giant Hornbill. Moreover, extract from K. laurina promotes also neurogenesis in living brain tissue after oxygen-glucose deprivation. In conclusion, extract from K. laurina not only controls and limits inflammatory reaction after primary neuronal damage, it promotes moreover neurogenesis if given hours until days after stroke-like injury.

Phenolic constituents from the wood of Morus australis with cytotoxic activity.

A new methylated flavonol, 5,7,2',4'-tetrahydroxy-3-methoxyflavone (1), had been isolated from the methanol extract of the wood of Morus australis, along with nine known compounds, kuwanon C (2), morusin (3), morachalcone A (4), oxyresveratrol (5), 4'-(2-methyl-2-buten-4-yl)oxyresveratrol (6), moracins M (7) and C (8), alboctalol (9), and macrourin B (10). The structures of these compounds were determined based on spectral evidence, including UV, IR, NMR, and mass spectra. Cytotoxic properties of compounds 1-10 were evaluated against murine leukemia P-388 cells. The prenylated stilbene 6 and 2-arylbenzofuran 8, and morusin (3) were found to have strong cytotoxic effects with IC50 values of 6.9, 8.7, and 10.1 microM, respectively.

Cytotoxic properties of oligostilbenoids from the tree barks of Hopea dryobalanoides.

A new modified stilbene dimer, diptoindonesin D (1), was isolated from the acetone extract of the tree bark of Hopea dryobalanoides, together with seven known compounds, parviflorol (2), (-)-balanocarpol (3), heimiol A (4), hopeafuran (5), (+)-alpha-viniferin (6), vaticanol B (7) and (-)-hopeaphenol (8). Cytotoxic properties of compounds 1-8 were evaluated against murine leukemia P-388 cells. Compound 8 was found to be the most active with IC50 of 5.7 microM.

A 2-arylbenzofuran derivative from Hopea mengarawan.

A new 2-arylbenzofuran derivative (diptoindonesin G) (1), along with nine known oligostilbenes, have been isolated and identified from the acetone extract of the tree bark of Hopea mengarawan. The structures of these compounds were determined based on spectroscopic data, including 2D NMR and HREIMS spectra. On cytotoxic evaluation of the isolated compounds against murin leukemia P-388 cells, compound 1 was the strongest in inhibiting the growth of the cells.

Oligostilbenoids from Shorea gibbosa and their cytotoxic properties against P-388 cells.

A new oligostilbenoid derivative, diptoindonesin F (1), along with five known oligostilbenoids, (-)-ampelopsin A (2), (-)-alpha-viniferin (3), ampelopsin E (4), (-)-vaticanol B (5), and (-)-hemsleyanol D (6), were isolated from the methanol extract of the tree bark of Shorea gibbosa. The structure of the new compound was determined based on the analysis of spectroscopic data, including UV, IR, NMR 1-D and 2-D, and mass spectra. Cytotoxic properties of the isolated oligostilbenoids were evaluated against murine leukemia P-388 cells with the result that compounds 2 and 4 showed the highest cytotoxicity.

Two new methyl chanofruticosinates from Kopsia flavida blume.

Two new indole alkaloids with the methyl chanofruticosinate skeletal system viz., methyl 3-oxo-12-methoxy-N1-decarbomethoxy-14,15-didehydrochanofruticosinate (1) and methyl 3-oxo-11,12-methylenedioxy-N-decarbomethoxy-14,15-didehydrochanofruticosinate (2), together with four known compounds, methyl 12-methoxy-N1-decarbomethoxychanofruticosinate, methyl 12-methoxychanofruticosinate, methyl 11,12-dimethoxychanofruticosinate and methyl 11,12-methylenedioxy-N1-decarbomethoxychanofruticosinate, were isolated in continuing studies on the leaves of Kopsia flavida Blume. The structures of the new indole alkaloids were assigned by NMR spectral data using various 2D-techniques.