Introduction: Aquilaria malaccensis, also known as “Pokok Karas” in Malaysia, is widely used in Southeast Asian countries for the treatment of joint pain, diarrhoea and inflammatory diseases, and has shown beneficial effects as an anticancer agent. The aim of this study was to investigate the effect of ethanol leaf extracts of A. malaccensis on MCF-7 cells. Methods: MTT-based cytotoxic and antiproliferative assay was used to determine the outcome of ethanolic extract toward MCF-7 cells. The mode of cell death was determined by the AO/PI double staining assay and the depolarisation of the mitochondria membrane potential. Results: IC50 value of the extract against MCF-7 cells treated for 72 hours was 4.1 ± 2.08 µg/mL, while the IC50 value for doxorubicin was 2.92 ± 0.12 µg/mL. The extract showed a lower cytotoxic effect against the NIH/3T3 cells and inhibited the growth of MCF-7 cells in a dose dependent manner. AO/PI double stain showed that the ethanolic extract of A. malaccensis leaves induced MCF-7 cells into apoptotic cell death. The present study showed that the ethanolic extract of A. malaccensis induced apoptosis through mitochondrial pathway as indicated by its ability to take up JC-1. Conclusion: The study found that ethanolic extract obtained from A. malaccensis leaves is cytotoxic on MCF-7 cells, resulting to apoptotic cell death of the cells.

Aims: This study was aimed to investigate the effects of methanol extracts from various parts of the Pereskia bleo Kuhn plant on Acanthamoeba sp. The antioxidant levels of each extract from different plant parts were measured after the extraction process. These extracts were then exposed to Acanthamoeba sp. to assess dose-response, IC50 values, changes in cell morphology, internal cell activity and apoptosis based on alterations in phospholipids. Methodology and results: The total phenolic content, carotenoid estimation and antioxidant activity of the leaves, flowers and fruits of P. bleo were measured based on 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) assay. Its anti-amoebic properties were tested using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay for the IC50 determination. The morphological and biochemical changes in the Acanthamoeba sp. were observed under light and fluorescence microscopy using the acridine orange and propidium iodide double staining (AO/PI). The IC50 values of P. bleo leaves, flowers and fruits methanolic extracts were 5.884%, 0.1646% and 20.69%, respectively. Morphological observation displayed shortened acanthapodia with darkened cytoplasms. AO/PI-stained Acanthamoeba sp. cells appear with orange-fluorescent organelles in their green cytoplasm, indicating autophagic cell deaths. Apoptotic and necrotic Acanthamoeba sp. cells were absent based on Annexin V labelling. Conclusion, significance and impact of study: This study confirmed that the methanolic crude extracts of P. bleo exhibit high cytotoxic potential towards Acanthamoeba sp. trophozoites by inducing an autophagic mode of cell death.