Biological activities of leaf extracts from selected species and their relationship with bufadienolides content.

Context: species (Crassulaceae) are widely used in traditional medicine as remedies in infectious diseases and cancer treatment.

Objective: Cytotoxic and antimicrobial activities of Raym.-Hamet & H. Perrier, (Lam.) Pers., and Poelln. extracts were determined. The relationship between biological activities and the extracts bufadienolides content was also investigated.

Materials And Methods: Fresh leaves of species were macerated with 95% ethanol or water. The quantitative analysis of bufadienolides in the extracts was carried out with mass spectrometry. Cytotoxicity tests were performed on human cancer cell lines - HeLa, SKOV-3, MCF-7, and A375 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and Real-Time Cell Analysis system. The microbiological study was done using a few bacteria strains (β-hemolytic , , , , , ) and .

Results: The ethanol extract and water extract exhibited the most potent cytotoxic activity (IC < 19 µg/mL for HeLa and SKOV-3 cells). The strongest antibacterial effects showed ethanol extract of and (MIC values were 8.45, 8.45, 0.25 and <33.75 µg/mL for , , and respectively). The highest total amount of bufadienolides was in ethanol extract. In contrast, ethanol extract did not show the presence of these compounds.

Conclusions: ethanol extract is a potential candidate for cancer and bacterial infection treatment. Additionally, the biological effects of extracts are not dependent on the presence and amount of bufadienolides in the plant extracts.