INTRODUCTION: Imaging techniques involving optical coherence tomography, computed tomography (CT) and high-resolution magnetic resonance imaging (MRI) are used as tools to identify atherosclerotic plaques. However, the effects of water-based contrast media used in Post Mortem Computed Tomography Angiography (PMCTA) on the histopathology of atherosclerotic plaques have not been widely explored. The objective of this study is to determine the effects of water-based contrast media used in PMCTA on the histopathology of atherosclerotic plaques and biomarkers of atherosclerosis in experimentally induced established atherosclerotic rabbits. MATERIALS AND METHODS: Twenty male New Zealand white rabbits were divided into 2 groups. One group was given a high cholesterol diet (HCD) for 12 weeks to establish atherosclerosis and the control group normal diet (ND). Five rabbits from each group were then given intravenous water-based contrast media before being sacrificed. The entire length of aorta was dissected and submitted for histopathological examination and determination of tissue biomarkers α-SMA and MMP-9. RESULTS: Histopathological examination of the aorta including percentage of area covered by plaque and foam cell formation showed no significant difference in atheromatous plaque formation in both groups of HCD rabbits with or without intravenous contrast media injection (plaque: 55±41 vs. 63±15, p=0.731; foam cells: 124±83 vs. 171±55, p=0.325). Similarly, α-SMA and MMP-9 protein expression also showed no significant difference in both groups (α-SMA: 70±20 vs. 67±26, p=0.807; MMP-9: 60±12 vs. 57±17, p=0.785). CONCLUSION: Water-based contrast media used in PMCTA does not affect the morphology or the immunohistochemistry staining of SMA and MMP-9 in atherosclerotic plaques.

The positive response to tamoxifen in ERa-positive breast cancer patients is usually of a short duration as many of the patients eventually develop resistance. Our preliminary results show that aloe emodin extracted from the leaves of the Aloe barbadensis Miller demonstrated a cytotoxicity that is selective to ERa-positive breast cancer cells (MCF-7), but not to ERa-negative breast cancer cells (MDA-MB-231) and to the control cells (MCF-10A). The objective of this study was to test the hypothesis that aloe emodin may enhance the response of MCF-7 cells to treatment with tamoxifen. MCF-7 cells were treated with aloe emodin alone, tamoxifen alone or a combination of emodin and tamoxifen, at their respective IC 50 concentrations and at different time points of 24 hours, 48 hours and 72 hours. The respective IC 50s were the concentrations of aloe emodin and tamoxifen required to achieve 50% inhibition of the cells in the study. Cell viability and apoptosis were determined using trypan blue exclusion and DNA fragmentation assays, respectively. The involvement of RAS/MEKs/ERKs genes of MAPK signalling pathways with aloe emodin was determined using QuantiGene 2.0 Plex assay. Data was evaluated using the one-way ANOVA test. Our findings showed that aloe emodin enhanced the cytotoxicity of tamoxifen on MCF-7 cells through apoptosis by downregulation of MEK1/2 genes. Our research may provide a rational basis for further in vivo studies to verify the efficacy of a combination of aloe emodin and tamoxifen on the viability of ERa-positive-breast cancer cells.