In Vitro Cytotoxic Analysis of Ethanolic Extract from Leaves of Kalanchoe blossfeldiana Poelln (Crassulaceae)

The idea of harmlessness “Natura doesn’t hurt” is quite common, due to the lack of knowledge of the floral biology of some species, especially ornamental ones, as these studies are recent in Brazil. The present study aimed to perform an in vitro cytotoxicity analysis of the leaves of the ornamental plant Kalanchoe blossfeldiana Poelln on human red blood cells. After approval of the research project by the Brazilian Ethics Committee, identification of the plant by an Herbarium and selection of volunteers for the research by signing the TCLE and TCPE, the plant was purchased from a local florist and taken to the laboratory, since it is a plant grown in florists. The leaves were washed and 200 g were standardized, followed by grinding, maceration of the leaves in 95% ethanol and evaporation of the solvent. The cytotoxicity test was performed on red blood cells, in which the extract was diluted in six different concentrations and incubated with red blood cell washes for 1 hour. Immediately after, the samples were centrifuged and the absorbance of the supernatant was measured at 540 nm by spectrophotometry. From the results, the hemolysis percentages and statistical analysis were calculated using GraphPad Prism 7.0® software, with results at p<0.01 considered statistically significant. Hemolysis was observed in all concentrations compared to the control and that this hemolysis percentage increased proportionally to the extract concentration. It is concluded that the leaf extract shows signs of toxicity, revealing that care must be taken when cultivating the species, so that its leaves are not ingested.