Inhibition of 7,12-dimethylbenz[a]anthracene induced mouse skin carcinogenesis by Artemisia capillaris.

Anticarcinogenic activity of medicinal herbs (Artemisia capillaris, Taxus cuspidata, Anthriscus sylveatris, and Curcuma longa) was examined for 7,12-dimethylbenz[a]anthracene (DMBA)-induced mouse skin carcinogenesis. Four types of solvent fractions (hexane, chloroform, ethyl acetate, and butanol) were prepared from the methanolic extract of medicinal herbs. The cytotoxicity and anticarcinogenic activities of solvent fractions were examined for mouse leukemia L1210 cancer cells and for female ICR mouse epidermal carcinogenesis induced by DMBA, respectively. The chloroform fraction of Artemisia capillaris, Taxus cuspidata, and Anthriscus sylveatris was more toxic to L1210 cells than other solvent fractions. The chloroform fraction of Artemisia capillaris markedly reduced the number of tumors/mouse and tumor incidence relative to that of other medicinal herbs tested. Major active chemical constituents in the chloroform fraction of Artemisia capillaries were found to be camphor, 1-borneol, coumarin, and achillin when analyzed by TLC and GC-MS. These results suggest that Artemisia capillaris was the most effective anticarcinogenic medicinal herb for DMBA-induced mouse epidermal carcinogenesis among 4 medicinal herbs tested, and the effect might be attributed to chemical compounds of camphor, 1-borneol, coumarin, and achillin.

Growth inhibition of osteosarcoma cell MG-63 by a mixture of trans,trans conjugated linoleic acid isomers: possible mechanistic actions.

The growth inhibitory effect of a mixture of t,t conjugated linoleic acid isomers (t,t CLA) was investigated in the human osteosarcoma cell MG-63, with references to c9,t11 and t10,c12 CLA isomers. The t,t CLA effectively induced a cytotoxic effect in a time-dependent (0 to 6 d) and concentration-dependent (0 to 40 microM) manner, as compared to the reference and control treatments. The apoptosis and cell cycle related parameters were measured on the cells treated with 40 microM t,t CLA for 4 d. Flow cytometric analysis revealed that the t,t CLA treatment effectively increased the proportion of apoptotic cells with a low DNA content (sub G0/G1) and a marked loss of cells from the G0/G1 phase of the cell cycle, relative to other treatments. The occurrence of the characteristic morphological changes and DNA fragmentation confirmed the apoptosis. The level of Bax protein was increased, whereas the Bcl-2 expression was reduced. In addition, cytochrome c was released from the mitochondria into the cytosol, and the activation of caspase-3 led to the cleavage of poly (ADP-ribose) polymerase (PARP). Moreover, the composition of linoleic and arachidonic acids in membrane was decreased by increase in t,t CLA. These findings suggest that t,t CLA incorporation in membrane activates a mitochondria-mediated apoptosis pathway that can enhance the antiproliferative effect of t,t CLA in the osteosarcoma cells.