Anti-cancer volatile constituents from the flowers of lonicera japonica thunb. Cultivated in Egypt
The volatile constituents of the flowers of Lonicera japonica Thunb. (Japanese honeysuckle), obtained by two methods [viz., floral absolute volatiles (FAV) and hydrodistilled/hexane extracted volatiles (HHV)], were comparatively investigated as regards composition and cytotoxicity. Hydrodistillation/hexane extraction was performed in Likens-Nickerson apparatus. The volatile constituents were identified and quantitated using GC/MS. Sixty compounds, 44 of which have not been previously reported in L. japonica, were identified among the volatiles prepared by the two methods. Linalool was the major constituent in both cases. However, its percentage is higher in the floral absolute volatiles (47.92%). On the other hand, 4-terpineol, nerolidol, cis-jasmone, cis-3-hexenyl tiglate, methyl palmitate and trans-linalool oxide, were detected in lesser but appreciable quantities in both samples. The volatiles prepared by the two methods were tested for their cytotoxic activities against four human cancer cell lines. The floral absolute showed a notable cytotoxic activity on the brain cancer cell line U251 (IC50 value of 7.92 μg/ml (and was found to be more potent than cisplatin reference drug (IC50 =8.66 μg/ml). Meanwhile, the volatiles prepared by hydrodistillation/hexane extraction showed a considerable cytotoxic activity on the liver cancer cell line Hepg2 with IC50 value of 7.58 μg/ml.
Egyptian Journal of Biomedical Sciences Vol. 23 (1) 2007: pp. 135-145