Study on the Phototoxicity and Antitumor Activity of Plant Extracts from Tanacetum vulgare L., Epilobium parviflorum Schreb., and Geranium sanguineum L.

Our country is rich in medicinal plants with a thousand-year tradition of use for therapeutic and cosmetic purposes. World Health Organization estimates that around 70% of population is using traditional (folk) medicine to cure various ailments. In many cases, herbal preparations prove to be useful, but some of them can also exert toxic effects. Therefore, herbal extracts should be tested both as curatives and for safety application. The aim of the present work was to investigate extracts from Tanacetum vulgare (TVA), Epilobium parviflorum (EPE) and Geranium sanguineum (GSA), obtained by different organic solvents, for their phototoxicity and anticancer activity. The standard BALB/c 3T3 Neutral Red Uptake phototoxicity/cytotoxicity assay was used to evaluate the possible phototoxic properties of the extracts. The antitumor activity of the extracts was studied in vitro on a panel of human tumor cell lines in comparison to the non-tumorigenic MCF-10A cells. The selectivity indices and the photo-irritancy factors were determined. The results show that the studied extracts are not phototoxic at concentration range from 4 to 1000 μg/ml. Determined photo-irritancy factors (PIF) for the extracts was < 2 (PIF for EPE = 1.72, GSA = 1.04, TVA = 1.43), which assigns them to the category of non-phototoxic substances. In addition, at concentrations lower than < 60 μg/ml, no statistically significant cytotoxicity was observed. The selectivity index was calculated relative to the IC50 value for non-tumorigenic MCF-10A cells. The highest selective index obtained with respect to the HT-29 cells was shown by all testing extracts (selective index (SI) for EPE = 2.6, GSA = 2.4 and TVA = 2.5), to the HeLa cells by extract GSA (SI = 2.0) and to the PC3 cells by extracts GSA (SI = 2.6) and TVA (SI = 2.0). Presented data shows that the studied extracts have a high level of photosafety with a promising antitumor activity in certain cell lines