Contaminants of PC-SPES are not responsible for cytotoxicity in human small-cell lung carcinoma cells

Evaluation of transcriptional activity of caspase-3 gene as a marker of acute neurotoxicity in rat cerebellar granular cells

Caspase-3 is a key protein involved in the classical apoptosis mechanism in neurons, as in many other cells types. In the present research, we describe the transcriptional activity of caspase-3 gene as a marker of acute toxicity in a primary culture model of rat cerebellar granule neurons (CGNs). CGNs were incubated for 16h in complete medium containing the chemicals at three concentrations (10, 100microM and 1mM). A total of 48 different compounds were tested. Gene transcriptional activity was determined by low-density array assays, and by single Taqman caspase-3 assays. Results from the PCR arrays showed that the caspase-3 gene was up-regulated when CGNs were exposed to neurotoxic chemicals. Significative correlations were found between the transcriptional activity of caspase-3 and the activity of some other genes related to apoptosis, cell-cycle and ROS detoxification. In our experiments, acute exposure of CGNs to well-documented pro-apoptotic xenobiotics modulated significantly caspase-3 gene expression, whereas chemicals not related to apoptosis did not modify caspase-3 gene expression. In conclusion, acute exposure of CGNs to neurotoxic compounds modulates the transcriptional activity of genes involved in the classical apoptotic pathway, oxidative stress and cell-cycle control. Transcriptional activity of caspase-3 correlates significantly with these changes and it could be a good indicator of acute neurotoxicity.

Anticancer activity of extracts derived from the mature roots of Scutellaria baicalensis on human malignant brain tumor cells

Background

Flavonoid-rich extracts from the mature roots of Scutellaria baicalensis have been shown to exhibit antiproliferative effects on various cancer cell lines. We assessed the ability of an ethanolic extract of S. baicalensis root to inhibit the proliferation of malignant glioma cells.

Methods

Cell lines derived from primary and recurrent brain tumors from the same patient and cells selected for resistance to the chemotherapeutic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) were used to identify antiproliferative effects of this extract when used alone and in conjunction with BCNU.

Results and discussion

Results indicated that Scutellaria baicalensis not only inhibits cellular growth in recurrent and drug resistant brain tumor cell lines, but also demonstrates an increased inhibitory effect when used in conjunction with BCNU.

Conclusion

The results of this study support the efficacy of S. baicalensis as an anticancer agent for glioblastomas multiforme and a potential adjuvant treatment to current chemotherapeutic agents used in the treatment of both primary and recurrent GBMs. Further studies of the effects of individual flavonoids alone and in combination with each other and with currently used therapies are needed.