Antitumor and antiviral activities of Magnolia grandiflora L. leaves growing in Egypt
Magnolia grandiflora L. (Magnoliaceae) is used in traditional medicine for treatment of fever, diarrhea, rheum and arthritis. A number of biologically active alkaloids, sesquiterpenes, phenolic compounds, neolignans have been isolated from this species. Bioassay guided fractionation of methanol extract of Magnolia grandiflora L. leaves led to isolation and characterization of four aporphine alkaloids, magnoflorine, lanuginosine, liriodenine and anonaine. The structure of these compounds was determined on the basis of spectroscopic studies. Cytotoxicity of pure compounds magnoflorine and lanuginosine were determined in tumor cell lines, Hela (cervix tumor cell line), HEPG2 (hepatocellular carcinoma cell line) and U251(brain tumor cell line). The cell viability tests were performed as described previously . Magnoflorine and lanuginosine displayed a significant activity in vitro against (HEPG2) cancer cell line. Magnoflorine was more cytotoxic (IC50 0.4µg/ml) than lanuginosine (IC50 2.5µg/ml) against (HEPG2). In addition, the activity of Magnoflorine was comparable with those of standard doxorubicin (IC50 0.27µg/ml). Furthermore, magnoflorine and lanuginosine exhibited cytotoxicity against brain tumor cell line U251 with IC50 7µg/ml and 4µg/ml, respectively. The two compounds were found to be inactive against Hela cancer cell. On the other hand, the antiviral activity of methanol extract was investigated against two viruses: Herpes simplex virus type -1 (HSV-1) and Poliovirus type-1 (PV-1) using Plaque reduction assay . Methanol extract showed high inhibition of herpes simplex virus (HSV-1) (76.7%) at 1.1µg/ml whereas the extract exhibited a moderate antiviral activity against Poliovirus type 1 (47%) at same concentration. In conclusion, magnoflorine and lanuginosine might be valuable antitumor promoting agent and methanol extract is potent antiviral agent against HSV-1 virus that can be exploited for development of an alternative remedy for HSV-1 infection.
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