Cytotoxic activity of methanol extracts from Basidiomycete mushrooms on murine cancer cell lines.

Crude methanol extracts of 58 mushroom species were screened for their cytotoxic activities against two murine cancer cell lines, L1210 and 3LL, using the tetrazolium assay. A majority of extracts (74%) exhibited IC50 > 100 microg/ml against both cell lines. A most marked activity against one of the cell lines was noted for nine species (14% of the tested species). While Amanitales and Russulales tested were not found active, Polyporales and Boletales gave better results. Four species exhibited a significant cytotoxic activity (IC50 < or = 20 microg/ml) against at least one of the two murine cancer cell lines (Ganoderma lucidum, Meripilus giganteus, Suillus granulatus, S. luteus). The last one had never been investigated for its cytotoxic compounds before.

Cytotoxic activity of some lichen extracts on murine and human cancer cell lines.

Eight lichens were extracted successively with n-hexane, diethyl ether and methanol using a Soxhlet process. The cytotoxic activity of the 24 lichen extracts was evaluated in vitro using two murine (the L1210: lymphocytic leukaemia, and the 3LL: Lewis lung carcinoma) and four human (the K-562: chronic myelogenous leukaemia, the U251: glioblastoma, the DU145: prostate carcinoma, and the MCF7: breast adenocarcinoma) cancer cell lines and non-cancerous cells, the Vero cell line (African green monkey kidney cell line). The MTT assay revealed significant cytotoxicity (IC50 < or = 20 microg/ml) on one of the tested cancer cell lines for at least one extract of each lichen species. Some extracts of Cladonia convoluta, Cladonia rangiformis, Parmelia caperata, Platismatia glauca and Ramalina cuspidata demonstrated interesting activities particularly on human cancer cell lines as good selectivity indices were recorded (SI > 3).

In vitro antiviral activity of thirty-six plants from La Réunion Island.

Methanol extracts of 36 medicinal plants from La Réunion Island were evaluated against two viruses: Herpes simplex type 1 (HSV-1) and poliovirus type 2 (PV). Five of them showed an effect against HSV-1 and five against PV, Senecio ambavilla being inhibitor for both viruses.

Antiviral and cytotoxic activities of some Indonesian plants.

Ten methanolic extracts from eight Indonesian medicinal plants were phytochemically screened and evaluated for antiviral (HSV-1 and Poliovirus) and cytotoxic activities on murine and human cancer lines (3LL, L1210, K562, U251, DU145, MCF-7). Besides Melastoma malabathricum (Melastomataceae), the Indonesian Loranthaceae species among which Elytranthe tubaeflora, E. maingayi, E. globosa and Scurrula ferruginea exhibited attractive antiviral and cytotoxic activities. Piper aduncum (Piperaceae) was found active on Poliovirus. S. ferruginea was selected for further studies because of its activity on the U251 glioblastoma cells.

A prenyloxycoumarin from Psiadia dentata.

A new coumarin identified as 5-hydroxy-6-methoxy-7-(3-methyl-but-2-enyloxy)-2H-1-benzopyran-2-one (isoobtusitin) was isolated from Psiadia dentata. This compound showed, in vitro, a moderate inhibitory activity against poliovirus and a very weak activity against (HIV), whereas it was inactive against (HSV1), (VSV), and murine tumoral cell lines (3LL, L1210).

Antipoliovirus flavonoids from Psiadia dentata.

The search for antiviral agents against vesicular stomatitis virus, herpes simplex virus type 1 and poliovirus type 2 in plants extracts, led to the isolation of two antipoliovirus flavonoids from the medicinal plant Psiadia dentata (Cass.) DC, Asteraceae: 3-methylkaempferol and 3,4'-dimethylkaempferol. The antipoliovirus activity of both compounds was estimated by comparison with 3-methylquercetin, guanidine and Ro-090179. The most potent inhibitor of poliovirus replication was 3-methylkaempferol, and therefore we investigated its mechanism of action. We showed, using the inhibition of [3H]uridine incorporation in viral RNA and performing a dot-blot with one RNA probe specific for the poliovirus genomic strand RNA, that 3-methylkaempferol inhibits the genomic RNA synthesis of poliovirus.

Antipoliovirus structure-activity relationships of some aporphine alkaloids.

A series of 18 aporphinoids have been tested in vitro against human poliovirus. The aporphines (+)-glaucine fumarate (1), (+)-N-methyllaurotetanine (4), (+)-isoboldine (7), and (-)-nuciferine, HCl (10) were found to be active with selectivity indices > 14. The nature of the 1, 2-substituents of the isoquinoline moiety appeared to be critical for antipoliovirus activity. An SAR study demonstrated the importance of a methoxyl group at C-2 on the tetrahydroisoquinoline ring for the induction of antipoliovirus activity. Molecular modeling of some compounds in this series revealed the close similarities between the three-dimensional conformational features of the inactive 1,2-substituted derivatives (+)-boldine (6) and (+)-laurolitsine (5) with derivatives containing the 1,2-(methylenedioxy) moiety, which were generally found to be inactive as exemplified by (+)-cassythicine (9).

Anti-herpes virus activity of aporphine alkaloids.

We evaluated, in cell cultures, the action of a series of 19 aporphine alkaloids against Herpes simplex virus type 1 (HSV-1). On the basis of viral titre reduction, six alkaloids were found to be active. The mode of action of the three most potent inhibitors, oliverine HCl, pachystaudine, and oxostephanine, was studied. These compounds did not have any virucidal or prophylactic effect but they were shown to interfere with the viral replicative cycle. Although DNA synthesis was reduced, their exact target remains to be elucidated. In the discussion, some structure-activity relationships are considered.

Comparison of the anti-herpes simplex virus activities of propolis and 3-methyl-but-2-enyl caffeate.

The in vitro activity against herpes simplex virus type 1 of 3-methyl-but-2-enyl caffeate isolated from poplar buds or prepared by synthesis was investigated. Under conditions of one or multiple multiplication cycles, this compound, which is a minor constituent of propolis, was found to reduce the viral titer by 3 log10, and viral DNA synthesis by 32-fold.