Toxicological assessment of niga-ichigoside F1 and 2β,3β-19α-trihydroxyursolic acid derived from <i>Rubus imperialis</i> (Rosaceae): determining the safety using human peripheral blood mononuclear cells (PBMC)

<i>Rubus imperialis</i> Chum. Schl. (Rosaceae) is used in traditional medicine as a remedy to treat diabetes and other diseases. However, there are reports that the extract of this plant and others of the <i>Rubus</i> genus may produce cellular and/or genetic toxicity. Niga-ichigoside F1 (NIF1) and 2β,3β-19α-trihydroxyursolic acid (2B) are major compounds found in <i>R. imperialis</i> extract known to exert pharmacological effects which may be responsible for the observed toxicity. Thus, this study was aimed to examine the cytogenotoxic potential of NIF1 and 2B in human peripheral blood mononuclear cells (PBMC) following acute exposure. Cytotoxicity was determined by trypan blue staining and genotoxicity by micronucleus and comet assays. Data obtained showed that both compounds, at concentrations ranging from 0.1 and 20 µg/ml, did not markedly affect cell viability. In addition, genetic toxicity testing (comet assay) detected no evidence of DNA damage or chromosomal mutations by the micronucleus test. Under these experimental conditions and considering that both compounds exhibit biological effects at low concentrations, it may be concluded that NIF1 and 2B did not induce cytogenotoxic effects in primary human PBMC.