In Vivo and in vitro antitumor activity of tomatine in hepatocellular carcinoma.

Background: There is abundant ethnopharmacological evidence the uses of regarding Solanum species as antitumor and anticancer agents. Glycoalkaloids are among the molecules with antiproliferative activity reported in these species. Purpose: To evaluate the anticancer effect of the Solanum glycoalkaloid tomatine in hepatocellular carcinoma (HCC) in vitro (HepG2 cells) and in vivo models. Methods: The resazurin reduction assay was performed to detect the effect of tomatine on cell viability in human HepG2 cell lines. Programmed cell death was investigated by means of cellular apoptosis assays using Annexin V. The expression of cancer related proteins was detected by Western blotting (WB). Reactive oxygen species (ROS) and calcium were determined by 2,7-dichlorodihydrofluorescein diacetate and Fluo-4, respectively. Intrahepatic HepG2 xenograft mouse model was used to elucidate the effect of tomatine on tumor growth in vivo. Results and Discussion: Tomatine reduced HepG2 cell viability and induced the early apoptosis phase of cell death, consistently with caspase-3, -7, Bcl-2 family, and P53 proteins activation. Furthermore, tomatine increased intracellular ROS and cytosolic Ca+2 levels. Moreover, the NSG mouse xenograft model showed that treating mice with tomatine inhibited HepG2 tumor growth. Conclusion: Tomatine inhibits in vitro and in vivo HCC tumorigenesis in part via modulation of p53, Ca+2, and ROS signalling. Thus, the results suggest the potential cancer therapeutic use of tomatine in HCC patients.

Nutritional composition, antioxidant activity and isolation of scopoletin from Senecio nutans: support of ancestral and new uses.

Continuing with our study characterising Senecio nutans Sch. Bip., we have isolated and identified a simple coumarin, scopoletin, that could be relevant for the biological properties of the species related with the ancestral medical uses. This is the first report of scopoletin from S. nutans. In addition, the extract was analysed for its antioxidant activity using the ABTS and FRAP method as well as providing the first nutritional analyses of this plant from northern Chile highlands.

The selective cytotoxicity elicited by phytochemical extract from Senecio graveolens (Asteraceae) on breast cancer cells is enhanced by hypoxia.

Breast cancer is the second cause of cancer­related deaths in woman and the incidence of the disease has increased worldwide, in part due to improvements in early detection. Several drugs with anticancer effects have been extracted from plants in the last 20 years, many of which are particularly effective against breast cancer cells. In particular, we have become interested in the ethanolic extract from Senecio graveolens (synonym of S. nutans), a plant commonly called Chachacoma, in an effort to isolate compounds that could demonstrate cytotoxic effects on breast cancer cells. Senecio (Asteraceae) is the largest gender in Chile comprising approximatly 200 species. These herbs inhabit areas over 3,500 meters above the sea level in the Andes Mountains. S. graveolens is commonly used by local communities for its medicinal properties, particularly its capacity to ameliorate high-altitude-associated sickness. The cytotoxic effect of the alcoholic extract from S. graveolens, as well as its most abundant compound 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone, were tested in the breast cancer cell lines ZR-75-1, MCF-7 and MDA-MB­231, and non-tumorigenic MCF-10F cells. We show that the phytochemical extract was able to induce cytotoxicity in cancer cells but not in MCF-10F. Importantly, this effect was enhanced under hypoxic conditions. However, 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone, the main compound, did not by itself show an effective anticarcinogenic activity in comparison to the whole extract. Interestingly, the cytotoxic effect of the phytochemical extract was dependent on the basal MnSOD protein expression. Thus, cytotoxicity was increased when MnSOD levels were low, but resistance was evident when protein levels were high. Additionally, the crude extract seems to trigger cell death by a variety of processes, including autophagy, apoptosis and necrosis, in MCF-7 cells. In summary, S. graveolens extract possess anticancer activity displaying a specific cytotoxic effect on cancer cells, thus serving as a potential source of phytochemical compounds for cancer treatment.