DNA Damage and Inhibition of Akt Pathway in MCF-7 Cells and Ehrlich Tumor in Mice Treated with 1,4-Naphthoquinones in Combination with Ascorbate

Abstract

The aim of this study was to enhance the understanding of the antitumor mechanism of 1,4-naphthoquinones and ascorbate. Juglone, phenylaminonaphthoquinone-7, and 9 (Q7/Q9) were evaluated for effects on CT-DNA and DNA of cancer cells. Evaluations in MCF-7 cells are DNA damage, ROS levels, viability, and proliferation. Proteins from MCF-7 lysates were immunoblotted for verifying PARP integrity, γH2AX, and pAkt. Antitumor activity was measured in Ehrlich ascites carcinoma-bearing mice. The same markers of molecular toxicity were assessed in vivo. The naphthoquinones intercalate into CT-DNA and caused oxidative cleavage, which is increased in the presence of ascorbate. Treatments caused DNA damage and reduced viability and proliferation of MCF-7 cells. Effects were potentiated by ascorbate. No PARP cleavage was observed. Naphthoquinones, combined with ascorbate, caused phosphorylation of H2AX and inhibited pAkt. ROS were enhanced in MCF-7 cells, particularly by the juglone and Q7 plus ascorbate. Ehrlich carcinoma was inhibited by juglone, Q7, or Q9, but the potentiating effect of ascorbate was reproduced in vivo only in the cases of juglone and Q7, which caused up to 60% inhibition of tumor and the largest extension of survival. Juglone and Q7 plus ascorbate caused enhanced ROS and DNA damage and inhibited pAkt also in Ehrlich carcinoma cells.

Juglone down-regulates the Akt-HIF-1α and VEGF signaling pathways and inhibits angiogenesis in MIA Paca-2 pancreatic cancer in vitro

“…resveratrol from grapes, capsaicin from pepper have shown inhibitory effect on HIF-1α and VEGF by inhibiting the Akt pathway (Min et al, 2004). Juglone at 20 μM in combination with ascorbate (1 mM) was recently shown to inhibit p-Akt in MCF-7 breast cancer cells (Ourique et al, 2015). Our results indicate that juglone by itself is very effective in inhibiting p-Akt at 5μM in pancreatic cancer MIA Paca-2 cells (Fig.…”

Antioxidant and Anticancer Roles of a Novel Strain ofBacillus anthracisIsolated from Vermicompost Prepared from Paper Mill Sludge

“…The present findings corroborate earlier anticancer study of crude extracts against MCF-7 cells and demonstrate a potent cytotoxicity at lower IC50 value. A good cytotoxic activity against He La cells was found with the application of crude extracts of B. thuringiensis isolated from mangrove sediments [ 32 , 33 ]. A cell line specific activity of cytotoxicity as noticed in the present study using bacterial extracts is supposed to be due to the presence of secondary metabolites as well as complexity in signal cascade guiding for apoptosis [ Figure 3 .].…”

Ganoderma lucidum polysaccharide enhances radiosensitivity of hepatocellular carcinoma cell line HepG2 through Akt signaling pathway

“…The Akt signaling pathway has been demonstrated to regulate multiple biological activities, including cell proliferation, apoptosis and differentiation ( 18 , 19 ). Upregulation of Akt is observed in numerous types of cancer, and it may be associated with uncontrolled cell growth ( 20 ).…”