A new bicoumarin from Stellera chamaejasme L

Rapid screening of diarylpentanoids from Daphne bholua

Fractionation motivated by biological activity screening and NMR characteristic signals analysis led to the isolation of seventeen diarylpentanoids from the whole plant of Daphne bholua Buch.-Ham. ex D. Don, among which nine compounds were undescribed. Their structures and stereochemistry were determined by comprehensive spectroscopic data, J-based configurational analysis, and quantum chemical calculations. The inhibitory potentials of all isolates against acetylcholinesterase were evaluated in vitro and in silico.

A new biflavone glucoside from the roots of Stellera chamaejasme

The present study investigated the chemical constituents of the roots of Stellera chamaejasme (Thymelaeaceae). One new biflavone glucoside (1), along with other thirteen known compounds (2-14), was isolated by repeated column chromatographic methods and their structures were elucidated on the basis of spectral analyses. The cytotoxic activities of selected compounds were evaluated against four human cancer cell lines (A549, BEL-7402, HCT-116, and MDA-MB-231) by the SRB assay method. Compound 9 showed remarkable cytotoxicity against BEL-7402 with IC50 value being 0.65 μg·mL(-1); compounds 7, 8, and 12 exhibited significant cytotoxic activity against A549 with IC50 values being 2.38, 1.57, and 2.35 μg·mL(-1), respectively.

In vitro inhibitory and pro-apoptotic effect of Stellera chamaejasme L extract on human lung cancer cell line NCI-H157

OBJECTIVE

To investigate the inhibitory and pro-apoptotic effect of Stellera Chamaejasme L extract (ESC) in vitro.

METHODS

ESC was first extracted with ethanol, and then washed using a polyamide column with 60% ethanol. ESC was then decompressively recycled and vacuum dried at room temperature to obtain active fractions. Subsequently, the cytotoxic and apoptotic effects of ESC on NCI-H157 human lung cancer cells were determined.

RESULTS

The results showed that ESC was rich in isomers of Chamaejasminor, neochamaejasmine and Sikokianin. ESC had significant cytotoxicity against NCI-H157 cells, with an IC50 of approximately 18.50 microg x mL(-). ESC caused significant increase in total apoptotic rate, the activity of caspase 3 and 8,

CONCLUSION

The inhibitory effect of ESC on NCI-H157 tumor cells might partly be attributed to its apoptotic induction through activation of the Fas death receptor pathway.

Stellettin A induces endoplasmic reticulum stress in murine B16 melanoma cells

Isomalabaricanes are a small class of rearranged triterpenoids obtained from marine sponges. Most of these are cytotoxic to tumor cells, but the underlying mechanism is not clear. In this study, it was demonstrated that stellettin A (1), obtained from Geodia japonica, inhibited the growth of B16F10 murine melanoma cells by the induction of endoplasmic reticulum stress and accumulation of unfolded proteins. Immunoblotting analysis revealed abnormal glycosylation patterns of two melanoma marker proteins, tyrosinase and tyrosinase-related protein 1, and the retention of these proteins in the endoplasmic reticulum. Compound 1 induced the upregulation of the unfolded protein chaperone, glucose-regulated protein 78, in a dose-dependent manner. Increase of autophagosome-associated protein light chain 3 (LC3) in a membrane-bound form (LC3II) and its immunofluorescence co-localization with tyrosinase suggest the possible removal of deglycosylated and unfolded proteins by autophagy of the cells. There was no change in either the expression of the apoptosis marker protein Bcl-2 or the appearance of apoptotic nuclei in 1-treated cells. Taken together, 1 is an endoplasmic reticulum stressor that inhibits the growth of B16 melanoma cells by induction of abnormal protein glycosylation and autophagy.