Epipremnum pinnatum (L.) Engl. hexane extract produced a significant growth inhibition against T-47D breast carcinoma cells and analysis of cell death mechanisms indicated that the extract elicited a non-apoptotic programmed cell death. T-47D cells exposed to the extract at EC(50) concentration (72 h) for 24 h failed to demonstrate typical DNA fragmentation associated with apoptosis, as carried out using a modified TUNEL assay. In addition, acute exposure to the extract produced an insignificant regulation of caspase-3 and p53 mRNA expression but increased in the c-myc mRNA expression. Ultrastructural analysis using transmission electron microscope demonstrated distinct vacuolated cells, which strongly indicated a Type II non-apoptotic cell death although the changes in chromatin were also detected. The presence of non-apoptotic programmed cell death was then reconfirmed with annexin-V and propidium iodide staining. These findings suggested that up-regulation of c-myc mRNA expression may have contributed to the growth arrest and Type II non-apoptotic programmed cell death in the Epipremnum pinnatum (L.) Engl. hexane extract-treated T-47D cells.
Andrographolide was extracted and purified from Andrographis panicula using hexane and water partitioning followed by ethyl acetate extraction and chromatography. It showed selective cytotoxicity to prostate cancer PC-3 cells in vitro. The morphological and biochemical changes induced by the extract in carcinoma PC-3 cell death were studied. In andrographolide-treated cells, evidence of apoptosis such as cell shrinkage and surface microvilli loss after 4-hour treatment and chromatin condensation and fragmentation in H&E-stained cells between 4 to 8 hours after treatment were observed. Under electron microscopy, membrane blebbing and apoptotic bodies formation were seen after 8-hour treatment. Using immunocytochemistry staining and cellular caspase-3 activity assay, andrographolide-treated cells showed considerable caspase-3 activation and caspase-8 in PC-3 cells at 4 and 2 hours after treatment, respectively. This suggests andrographolide-induced cell death was achieved through the apoptotic pathway, via the activation of an extrinsic caspase cascade.
Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.
The cytotoxicity of goniothalamin was found to be strong towards both cancerous (HGC-27, MCF-7, PANC-1, HeLa), and non-cancerous (3T3) cell lines, especially in cases of dividing cells. Drug exposure studies indicated that the cytotoxic action of goniothalamin was time- and dose-dependent. At the ultrastructural level, goniothalamin-induced cytotoxicity revealed a necrotic mode of cell death towards MCF-7 cells.