ABSTRACT
Disobulbin-D (DBD), a hepatotoxic furano norclerodane diterpenoid, was isolated by bio-guided fractionation from the rhizome of Dioscorea bulbifera L. In working toward elucidating the cellular and molecular mechanisms of DBD toxicity, we treated normal human liver cell line L-02 cells with DBD in vitro and evaluated its toxicity in terms of cell viability, morphologic changes, induction of apoptosis/necrosis, and caspase 3 activity. The viability of L-02 cells was inhibited by DBD in a concentration and time-dependent manner. Apoptosis was supported by the Annexin V and propidium iodide assay, Hoechst 33258 staining, and the occurrence of a sub-G(1) peak. DBD can cause an increase in caspase 3 activity, and pretreatment with Ac-DEVD-CHO blocked cell death and attenuated the apoptosis, showing that DBD-induced L-02 cell apoptosis is caspase 3-dependent. These results suggest that the effects of DBD on the growth of normal human liver L-02 cells may be due to its induction of cell apoptosis, which may also explain the toxicity observed in the plants containing furano clerodane diterpenoids.
Subject(s)
Apoptosis/drug effects , Diterpenes/toxicity , Drugs, Chinese Herbal/toxicity , Liver/drug effects , Plant Extracts/toxicity , Cell Line , Cell Survival/drug effects , Dioscorea , Diterpenes/chemistry , Drugs, Chinese Herbal/chemistry , Humans , Liver/pathology , Plant Extracts/chemistry , Rhizome/chemistry , Rhizome/toxicityABSTRACT
Three new compounds, debilitriol (1), debilignanoside (2), and equisetumine (3), along with nine known compounds, were isolated from the whole plant of Equisetum debile. Their structures were elucidated by spectral and chemical methods.
