METHODS: The experimental approach in the present study was based on a bioassay-guided fractionation. The crude methanol and fractionated extracts (hexane, chloroform and water) from different parts of A. scabra (leaves, rhizomes, roots and pseudo stems) were prepared prior to the cytotoxicity evaluation against human ovarian (SKOV-3) and hormone-dependent breast (MCF7) carcinoma cells. The identified cytotoxic extracts were then subjected to chemical investigations in order to identify the active ingredients. A normal human lung fibroblast cell line (MRC-5) was used to determine the specificity for cancerous cells. The cytotoxic extracts and fractions were also subjected to morphological assessment, DNA fragmentation analysis and DAPI nuclear staining.
RESULTS: The leaf (hexane and chloroform) and rhizome (chloroform) extracts showed high inhibitory effect against the tested cells. Ten fractions (LC1-LC10) were yielded after purification of the leaf chloroform extract. Fraction LC4 which showed excellent cytotoxic activity was further purified and resulted in 17 sub-fractions (VLC1-VLC17). Sub-fraction VLC9 showed excellent cytotoxicity against MCF7 and SKOV-3 cells but not toxic against normal MRC-5 cells. Meanwhile, eighteen fractions (RC1-RC18) were obtained after purification of the rhizome chloroform extract, of which fraction RC5 showed cytotoxicity against SKOV-3 cells with high selectivity index. There were marked morphological changes when observed using phase-contrast inverted microscope, DAPI nuclear staining and also DNA fragmentations in MCF7 and SKOV-3 cells after treatment with the cytotoxic extracts and fractions which were indicative of cell apoptosis. Methyl palmitate and methyl stearate were identified in the hexane leaf extract by GC-MS analysis.
CONCLUSIONS: The data obtained from the current study demonstrated that the cell death induced by cytotoxic extracts and fractions of A. scabra may be due to apoptosis induction which was characterized by apoptotic morphological changes and DNA fragmentation. The active ingredients in the leaf sub-fraction VLC9 and rhizome fraction RC5 may lead to valuable compounds that have the ability to kill cancer cells but not normal cells.
OBJECTIVE: This review was aimed to critically analyze the therapeutic viability and anticancer efficacy of Eurycoma longifolia in the treatment of cancer and also to propose its molecular and translational mechanism of cytotoxicity against cancerous cells.
RESULTS: Among a range of medicinally active compounds isolated from various parts (roots, stem, bark and leaves) of Eurycoma longifolia, 16 compounds have shown promising anti-proliferative and anticancer efficacies. Eurycomanone, one of the most active medicinal compounds of Eurycoma longifolia, displayed a strong dose-dependent anticancer efficacy against lung carcinoma (A-549 cells) and breast cancer (MCF-7 cells); however, showed moderate efficacy against gastric (MGC-803 cells) and intestinal carcinomas (HT-29 cells). The prime mode of cytotoxicity of Eurycoma longifolia and its medicinal compounds is the induction of apoptosis (programmed cell death) via the up-regulation of the expression of p53 (tumor suppressor protein) and pro-apoptotic protein (Bax) and downregulation of the expression of anti-apoptotic protein (Bcl-2). A remarkable alleviation in the mRNA expression of various cancer-associated biomarkers including heterogeneous nuclear ribonucleoprotein (hnRNP), prohibitin (PHB), annexin-1 (ANX1) and endoplasmic reticulum protein-28 (ERp28) has also been evidenced.
CONCLUSION: Eurycoma longifolia and its medicinal constituents exhibit promising anticancer efficacy and thus can be considered as potential complementary therapy for the treatment of various types of human cancers.
Purpose: In this study, we have investigated the cytotoxic effects of the B. javanica hexane, ethanolic extracts against colon cancer cells. HT29 colon cells were selected as an in vitro cancer model to evaluate the anticancer activity of B. javanica ethanolic extract (BJEE) and the possible mechanisms of action that induced apoptosis.
Methods: 3-(4,5-dimethylthiazol-2-yl)-2, 5,-diphenyltetrazolium bromide (MTT), lactate dehydrogenase, acridine orange/propidium iodide, and annexin-V-fluorescein isothiocyanate assays were performed to determine the antiproliferative and apoptosis validation of BJEE on cancer cells. Measurement of reactive oxygen species (ROS) production, caspase activities, nucleus factor-κB activity, and gene expression experiments was done to investigate the potential mechanisms of action in the apoptotic process.
Results: The results obtained from this study illustrated the significant antiproliferative effect of BJEE on colorectal cancer cells, with a concentration value that inhibits 50% of the cell growth of 25±3.1 µg/mL after 72 h of treatment. MTT assay demonstrated that the BJEE is selectively toxic to cancer cells, and BJEE induced cell apoptosis via activation of caspase-8 along with modulation of apoptosis-related proteins such as Fas, CD40, tumor necrosis factor-related apoptosis-inducing ligands, and tumor necrosis factor receptors, which confirmed the contribution of extrinsic pathway. Meanwhile, increased ROS production in treated cells subsequently activated caspase-9 production, which triggered the intrinsic pathways. In addition, overexpression of cytochrome-c, Bax, and Bad proteins along with suppression of Bcl-2 illustrated that mitochondrial-dependent pathway also contributed to BJEE-induced cell death. Consistent with the findings from this study, BJEE-induced cancer cell death proceeds via extrinsic and intrinsic mitochondrial-dependent and -independent events.
Conclusion: From the evidence obtained from this study, it is concluded that the BJEE is a promising natural extract to combat colorectal cancer cells (HT29 cells) via induction of apoptosis through activation of extrinsic and intrinsic pathways.