Calotropis Procera Induced Caspase-Dependent Apoptosis and Impaired Akt/mTOR Signaling in 4T1 Breast Cancer Cells.

INTRODUCTION: Calotropis procera (Aiton) Dryand (Apocynaceae) is an herb that has been commonly used in folk medicine to treat various diseases for more than 1500 years. AIMS: Our goal was to investigate the anti-metastatic effects of phenolics extracted from C. procera (CphE) against 4T1 breast cancer cells and in BALB/c mice. METHODS: 4T1 cells were treated with CphE and quercetin (positive control) at concentrations that inhibited cell viability by 50% (IC50). Levels of reactive oxygen species (ROS), wound healing, and protein expressions were determined following standard protocols. For the in vivo pilot study, the syngeneic BALB/c mouse model was used. 4T1 cells were injected into mammary fat pads. Tumors were allowed to grow for 9 days before gavage treatment with CphE (150 mg GAE/kg/day) or PBS (controls) for one week. Excised tumors, liver, and lungs were analyzed for gene and protein expression and histology. RESULTS: In vitro results showed that CphE suppressed cell viability through apoptosis induction, via caspase-3 cleavage and total PARP reduction. CphE also scavenged ROS and suppressed Akt, mTOR, ERK1/2, CREB, and Src activation contributing to cell motility inhibition. CphE reduced IR, PTEN, TSC2, p70S6, and RPS6, protein levels, which are proteins involved in the PI3K/Akt/mTOR pathway, suggesting this pathway as CphE primary target. In vivo results showed downregulation of ERK1/2 activation by phosphorylation in tumor tissues, accompanied by angiogenesis reduction in tumor and lung tissues. A reduction of Cenpf mRNA levels in liver and lung tissues strongly suggested anti-invasive cancer activity of CphE. CONCLUSION: CphE inhibited 4T1 cell signal pathways that play a key role in cell growth and invasion. The potential for in vitro results to be translated in vivo was confirmed. A complete animal study is a guarantee to confirm the CphE anticancer and antimetastatic activity in vivo.

Dark Sweet Cherry (Prunus avium) Phenolics Enriched in Anthocyanins Induced Apoptosis in MDA-MB-453 Breast Cancer Cells through MAPK-Dependent Signaling and Reduced Invasion via Akt and PLCγ-1 Downregulation.

Dark sweet cherries (DSCs) are rich source of phenolics known to exert anticancer and anti-invasive activities. This study elucidated the molecular mechanisms underlying the activity of DSC phenolics against MDA-MB-453 breast cancer cells In Vitro. Cells were treated with DSC phenolics in whole extract (WE), and fractions enriched in anthocyanins (ACN) and proanthocyanidins (PCN) at concentrations that inhibited cell growth by 50%. Results showed that DSC phenolics suppressed Akt and PLCγ-1 activation, and inhibited cell motility and invasion, but only ACN reached significance. The extrinsic and intrinsic apoptotic pathways were also activated by DSC phenolics via caspase-8 cleavage and increased Bax/Bcl-2 ratio, with ACN exhibiting significant activation and stronger PARP-1 cleavage. Furthermore, sustained activation of mitogen-activated protein kinases (MAPKs) ERK1/2 and p38 was observed wherein ERK1/2 (U0126) and p38 (SB203580) inhibitors confirmed crosstalk ERK1/2-Akt and MAPK intrinsic mitochondrial pathways. In conclusion, DSC phenolics inhibited MDA-MB-453 breast cancer cells by targeting cell signaling pathways that induce apoptosis and suppress cell invasion, with ACN showing enhanced chemopreventive activities.