Preclinical study of the medicinal plants for the treatment of malignant melanoma.

Melanoma is the most aggressive type of skin cancer and originates from pigment-containing cells called melanocytes. The incidence of melanoma has been increasing worldwide. In the current study, the cytotoxic and photo-cytotoxic activities of different medicinal plants from Lamiaceae (Salvia cedronella, Salvia chionantha, and Salvia adenophylla), Asteraceae (Klasea kurdica, Klasea bornmuelleri, and Achillea millefolium), Apiaceae (Cuminum cyminum, and Anethum graveolens), and Polygonaceae (Rumex crispus) families were studied against HT 144 (Human malignant melanoma) cancer cell lines. The activities were performed by employing the MTT assay. Moreover, the apoptotic effects of the plant extracts were investigated by flow cytometry with annexin V/PI dual staining technique. The production of intracellular ROS by DCFH-DA technique and the effects of TNF-α secretion on apoptosis were also investigated. All plant extracts exhibited cytotoxic, and photo-cytotoxic effects against HT 144 cancer cells. Salvia species and Klasea species induced apoptosis via intracellular ROS generation secreted by TNF-α. On the other hand, A. millefolium, C. cyminum, A. graveolens, and R. crispus extracts induced apoptosis due to the intracellular generation of ROS, but, via the different pathway. In conclusion, this study indicates that the tested medicinal plant extracts have the potential in the treatment of melanoma.

The anticancer activity of visnagin, isolated from Ammi visnaga L., against the human malignant melanoma cell lines, HT 144.

Melanoma is a cancer of melanocyte cells and has the highest global incidence. There is a need to develop new drugs for the treatment of this deadly cancer, which is resistant to currently used treatment modalities. We investigated the anticancer activity of visnagin, a natural furanochromone derivative, isolated from Ammi visnaga L., against malignant melanoma (HT 144) cell lines. The singlet oxygen production capacity of visnagin was determined by the RNO bleaching method while cytotoxic activity by the MTT assay. Further, HT 144 cells treated with visnagin were also exposed to visible light (λ ≥ 400 nm) for 25 min to examine the illumination cytotoxic activity. The apoptosis was measured by flow cytometry with annexin V/PI dual staining technique. The effect of TNF-α secretion on apoptosis was also investigated. In standard MTT assay, visnagin (100 µg/mL) exhibited 80.93% inhibitory activity against HT 144 cancer cell lines, while in illuminated MTT assay at same concentration it showed lesser inhibitory activity (63.19%). Visnagin was induced apoptosis due to the intracellular generation of reactive oxygen species (ROS) and showed an apoptotic effect against HT 144 cell lines by 25.88%. However, it has no effect on TNF-α secretion. Our study indicates that visnagin can inhibit the proliferation of malignant melanoma, apparently by inducing the intracellular oxidative stress.

Effect of Sideritis leptoclada against HT-144 human malignant melanoma.

Sideritis leptoclada O. Schwarz et P.H. Davis extracts were evaluated for its singlet oxygen production capacity using spectrophotometric method. The extracts producing singlet oxygen were then evaluated for cytotoxicity against malignant melanoma cancer (HT-144) and fibroblast (3T3) cell lines using the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. The photocytotoxicity against the HT-144 human melanoma cell line in the presence of illumination (∼≥400 nm) was also evaluated. In the standard MTT assay, the ethanol extract of S. leptoclada (100 µg/ml) showed 83.49±3.33% inhibition of HT-144 cancer cells, whereas in the illuminated MTT assay, it showed 77.46±1.97% inhibition of HT-144 cancer cells. The effects of ethanol extract on reactive oxygen species production, apoptosis, and tumor necrosis factor-α secretion were also evaluated on HT-144 cell lines. The extract triggered an increase in intracellular reactive oxygen species production and tumor necrosis factor-α secretion compared with the respective controls. Thus, the ethanol extract may cause apoptosis. The LC-MS/MS analyses of S. leptoclada ethanolic extract showed that it has quinic acid (137213±11.25 µg/g extract), malic acid (1468±0.16 µg/g extract), chlorogenic acid (881.7±0.06 µg/g extract), and apigetrin (223.2±0.13 µg/g extract) as major constituents. The ethanolic extract of S. leptoclada should be further investigated as a potential treatment for malignant melanoma cancer.