OBJECTIVE: In the present study, we investigated the cytotoxic effect of 80% ethanol extract of P. amarus and its marker constituents (phyllanthin, hypophyllanthin, gallic acid, niranthin, greraniin, phyltetralin, isolintetralin, corilagin and ellagic acid) on HCT116 and their underlying mechanisms of action.
METHODS: Their antiproliferative and apoptotic effects on HCT 116 were performed using MTT assay and flow cytometric analysis, respectively, while caspases 3/7, 8 and 9 activities were examined using the colorimetric method. The expression of cleaved poly ADP ribose polymerase enzyme (PARP) and cytochrome c proteins was investigated by the immune-blot technique.
RESULTS AND DISCUSSION: HPLC and LC-MS/MS analyses demonstrated that the extract contained mainly lignans and polyphenols. The plant samples markedly suppressed the growth and expansion of HCT116 cells in a concentration- and time-dependent manner with no toxicity against normal human fibroblast CCD18 Co. P. amarus extract, phyllanthin and gallic acid induced mode of cell death primarily through apoptosis as confirmed by the exteriorization of phosphatidylserine. Caspases 3/7, 8, and 9 activities increased in a concentration-dependent manner following 24h treatment. The expressions of cleaved PARP (Asp 214) and cytochrome c were markedly upregulated.
CONCLUSION: P. amarus extract, phyllanthin and gallic acid exhibited an apoptotic effect on HCT116 cells through the caspases-dependent pathway.
METHODS: This is a retrospective review of all patients with colorectal cancer operated from November 2017 to October 2018. Main variables of interest were demography, type and surgery, length of stay (LOS), and the involvement of proximal and distal doughnut. Postoperative complications were analysed using chi-square or Fisher exact and Mann-Whitney tests.
RESULTS: There were 23 patients with a mean age of 62.5 ± 12.2 years. The mean time from diagnosis to surgery was 97.1 ± 154.84 days. There were 12 patients in the LAAR group and 11 in the open anterior resection (OAR) group. Duration of surgery was shorter in OAR (129.58 ± 51.38 minutes) compared to LAAR (147.91 ± 39.37 minutes). Mean LOS was shorter in the LAAR group with 5±1.5 days compared to the OAR group of 7.42 ± 4.25 days. However, there was no significant P-value for both duration of surgery (P = 0.322) or LOS (P = 0.87). A total of 3 complications were recorded after OAR and 2 after LAAR. Both groups had clear proximal and distal margins with 16 (12-18.5) harvested lymph nodes in LAAR and 18 (16-22) in OAR, which were equal (P = 0.155).
CONCLUSION: This study reports a shorter LOS in the minimally invasive group of 2 days with similar oncologic resection outcomes. This shows that LAAR is feasible in Malaysia and has potential outcome benefits.
MAIN METHODS: Colon cancer HCT-116 cells were treated with 8-PN and subjected to MTT and acridine orange/propidium iodide (AO/PI) staining to investigate the cytotoxicity of 8-PN. Arrest of the cells at different phases of cell cycle was monitored in the presence of 8-PN. Moreover, the apoptotic effects of 8-PN was assessed via annexin V and caspase activity assays and compared to the untreated cells.
KEY FINDINGS: The findings showed that 8-PN revealed strong inhibitory effect against HCT-116 cells with an IC50 value of 23.83 ± 2.9 μg/ml after 48 h. However, at similar concentrations and experimental time-points, the compound did not show cytotoxic effect to non-cancerous colon cells (CCD-41). Annexin-V assay indicates that 38.5% and 14.4% of HCT-116 cells had entered early and late stages of apoptosis, respectively after exposure of the cells to 8-PN for 48 h. Caspase activity assay illustrates that apoptosis is activated through both intrinsic and extrinsic pathways. Moreover, flow cytometry cell cycle results indicate that treatment with 8-PN significantly arrested the HCT-116 cells at G0/G1 phase.
SIGNIFICANCE: These findings reveal that 8-PN has anti-proliferative activity against HCT-116 colon cancer cells via induction of intrinsic and extrinsic pathway-mediated apoptosis. Further investigations should be carried out to unravel the mechanistic pathways underlying these activities.