A microalga, Euglena tuba induces apoptosis and suppresses metastasis in human lung and breast carcinoma cells through ROS-mediated regulation of MAPKs

Abstract

BackgroundEuglena tuba, a microalga, is known for its excellent antioxidant and iron-chelation activities; however its anticancer efficacies have not been reported yet. This study investigates the antitumor and antimetastatic activities of 70 % methanolic extract of Euglena tuba (ETME) against human lung (A549) and breast cancer (MCF-7) cells in vitro. Moreover, we had examined ETME’s role in inducing intracellular ROS with the regulation of antioxidants and MAPK pathway.MethodsAnticancer activity of ETME was thoroughly studied using flow cytometry, confocal microscopy and western blotting; along with various biochemical assays for analysing ROS-induced regulation of antioxidant enzymes. Inhibition of invasion and migration of malignant cells by ETME were investigated by wound healing and zymographic studies. DNA–Protein interaction with ETME was also studied.ResultsETME inhibited the growth of both A549 (IC50 92.14 µg/ml) and MCF-7 cells (IC50 50.27 µg/ml) by inducing apoptosis, while remained non-toxic against nomral WI-38 cells (IC50 911.43 µg/ml). ETME treatment resulted in increasing Bax/Bcl-2 ratio, BID truncation and activation of caspase cascade. This ultimately leads to PARP degradation and apoptosis through the intrinsic and extrinsic pathway in both A549 and MCF-7 cells. Wound healing and gelatin zymography studies revealed that ETME significantly inhibited the invasion and migration of both A549 and MCF-7 cells dose-dependently through the downregulation of MMP-9. Further investigations showed that ETME selectively induces intracellular ROS, regulated the levels of intracellular antioxidants and suppresses the activation of ERK1/2, JNK, P38 mitogen-activated protein kinase pathways in both type of malignant cells. Further DNA and protein binding studies revealed that ETME strongly interact with DNA as well as protein attributing the possibilities of presence of components which are targeting the macromolecules in cancer cells. Moreover, when the identified compounds from ETME were examined for their cytotoxicities individually, it was found that they lost their specificities towards cancer cells and also attacked normal cells.ConclusionsOur study suggests that ETME retards the growth of both lung and breast cancer cells, in vitro, through multivariate mechanisms, proving its candidature for the development of better and safer drugs against these cancers.

S-Allyl Cysteine Alleviates Hydrogen Peroxide Induced Oxidative Injury and Apoptosis through Upregulation of Akt/Nrf-2/HO-1 Signaling Pathway in HepG2 Cells

“…Cell cycle analysis was performed according to a previously described method [ 15 ]. Briefly 4 × 10 5 cells were seeded in each well of a 6-well plate and incubated for 24 h. Then cells were either left untreated or treated with SAC for 2 h followed by exposure to 1 mM H 2 O 2 for 24 h. Harvested cells were then subjected to chilled 70 % ethanol fixation and RNase A (100 μ g/ml) treatment followed by treatment with propidium iodide (120 μ g/ml) to stain cellular DNA.…”

“…ROS levels were measured by DCFH 2 -DA staining followed by FACS analysis according to a previously described method [ 15 ]. Initially, each well of a 6-well plate was seeded with 4×10 5 cells and incubated for 24 h. Then cells were either left untreated or pre-treated with SAC for 2 h followed by exposure to 1 mM H 2 O 2 in the presence of SAC for another 2 h. Additionally, cells were pretreated with 1 mM H 2 O 2 followed by SAC treatment or none for different time points.…”

Design, Synthesis and Anti‐Cancer Activities of Benzyl Analogues of Garlic‐Derived Diallyl Disulfide (DADS) and the Corresponding Diselenides

“…High concentration of ROS induces cell death of cancer cells by damaging cellular DNA, protein and lipids . To investigate whether the diselenides induce cell death via ROS generation in MCF‐7 cells, fluorescent dye (DCFH‐DA) was used and the level of ROS was estimated upon the incubation of cells with diselenide compounds using the well‐established protocol . As the IC 50 of all diselenides 12–16 used in the present study were less than 1.0 μM, this 1.0 μM concentration was used for the determination of intracellular ROS level in MCF‐7 cells.…”

“…[23] To investigate whether the diselenides induce cell death via ROS generation in MCF-7 cells, fluorescent dye (DCFH-DA) was used and the level of ROS was estimated upon the incubation of cells with diselenide compounds using the well-established protocol. [24] As the IC 50 of all diselenides 12-16 used in the present study were less than 1.0 mM, this 1.0 mM concentration was used for the determination of intracellular ROS level in MCF-7 cells. Interestingly, an enhancement of ROS level in the range of 1.54-2.54 fold as compared to the control was observed in the presence of diselenides 12-16 as shown in Figure 8.…”

Euglena extract suppresses adipocyte-differentiation in human adipose-derived stem cells

“…Algae have been increasingly recognized as resources of bioactive compounds for the improvement of human health [ 38 ]. Several recent studies have revealed that treatment with Euglena improves hyperglycemia and induces apoptosis of lung and breast cancer cells [ 31 , 39 ]. However, to our knowledge, there has been no report showing the influence of Euglena on adipogenesis in hASCs.…”