Effect of ascorbic acid and X-irradiation on HL-60 human leukemia cells: the kinetics of reactive oxygen species

Micronucleated erythrocytes in peripheral blood from neonate rats fed by nursing mothers exposed to X-rays

Most women with breast cancer can become pregnant and give birth while undergoing radiation therapy and breastfeeding is generally not contraindicated. The induction of long-lived reactive species in proteins, such as casein by X-ray radiation and DNA damage to unexposed organisms, has been shown when ingesting irradiated cheese. To determine whether exposing lactating rats to X-rays increases the number of micronucleated erythrocytes (MNEs) in peripheral blood of their unexposed or breastfeeding rat pups, 15 female Wistar rats were divided into three groups: Negative control; Experimental group exposed to X-rays, and group exposed to X-rays plus vitamin C. The mothers of groups 2 and 3 were irradiated for three consecutive days after giving birth, returning them to their respective cages each time to continue lactation. A blood sample was taken from the mothers and pups at 0, 24, and 48 hr. Blood smears were stained with acridine orange to analyze MNEs. In mother rats, the frequency of micronucleated polychromatic erythrocytes (MNPCEs) increased significantly at 24 and 48 hr in both study groups exposed to radiation. Likewise, in rat pups the MNPCE and MNE frequencies increased in both groups with radiation and radiation plus vitamin C at 24 and 48 hr, and a protection from vitamin C was observed. In conclusion, the genotoxic damage produced in rat pups that were lactated by mothers irradiated with X-rays is possibly due to the effect of long-lived reactive species that were formed in the breast milk of female Wistar rats during the irradiation process.

Novel 3,4-diarylpyrazole as prospective anti-cancerous agents

Cancer is a leading cause of death globally. Despite therapeutic advancements the mortality rate of cancer is continuously increasing. Thus, it is important to identify and design potential therapeutic agents which can specifically bind with most common targets of cancer and inhibit tumor progression. The present work discloses the potential therapeutic application of the novel 3,4-diaryl 1H-pyrazoles as prospective anti-cancerous agent. The in silico molecular docking studies performed with 3,4-disubstituted pyrazoles as ligand with targets including DNA, BCL-2 and F1-ATP Synthase revealed strong binding affinity with DNA (-7.5 kcal/mol), BCL-2 (-8.1 kcal/mol) and F1-ATP Synthase (-7.2 kcal/mol). Furthermore, the in silico finding was validated with the in vitro cytotoxicity assay with human breast cancer cell line (MDA-MB-231). MDA-MB-231 cells treated with 3,4-diarylpyrazole resulted in an increase in annexin-V positive cells, production of reactive oxygen species (ROS), dissipation of the mitochondrial membrane potential and activation of caspase-3. Taken together, this study demonstrate that a novel synthesized 3,4-diarylpyrazoles, showed strong binding affinity against DNA, anti-proliferative activity and executed apoptosis through ROS-dependent caspase-3-mediated mitochondrial intrinsic apoptotic pathway against MDA-MB-231 cells. These findings increase our understanding of the molecular mechanism (s) by which 3,4-diarylpyrazoles can exert their anticancer activity and may contribute towards development of novel therapeutic agent against breast cancer.

Ascorbic acid does not reduce the anticancer effect of radiotherapy

The present study hypothesized that the therapeutic use of ascorbic acid (AsA) in combination with radiation may reduce therapy-related side effects and increase the antitumor effects. The aim of the study was to examine the association between the scavenged activity of AsA and the biological anticancer effect of hydroxyl (OH) radicals generated by X-ray irradiation. Cell survival, DNA fragmentation of human leukemia HL60 cells and the amount of OH radicals were investigated following X-ray irradiation and AsA treatment. The number of living cells decreased, and DNA fragmentation increased at AsA concentrations >1 mM. Electron spin resonance spectra revealed that X-ray irradiation generated OH radicals, which were scavenged by AsA at concentrations >75 µM. The AsA concentration inside the cell was 75 µM when cells underwent extracellular treatment with 5 mM AsA, which significantly induced HL60 cell death even without irradiation. No increase in the number of viable HL60 cells was observed following AsA treatment with irradiation when compared to irradiation alone. In conclusion, the disappearance of the radiation anticancer effects with AsA treatment in combination with radiotherapy for cancer treatment is not a cause for concern.

Effects of X‑ray irradiation in combination with ascorbic acid on tumor control

Our previous studies demonstrated that the combination of treatment with ascorbic acid (AsA) and X‑ray irradiation results in increased apoptosis in HL60 cells. The present study was performed to investigate the effects of the combined use of AsA and X‑ray irradiation on epithelial cancer and sarcoma cells, and its potential use in future clinical treatment. X‑ray irradiation combined with AsA treatment resulted in increased suppression of cell growth of HT1080, SAS and A549 cells in vitro compared with X‑ray irradiation alone. The combined treatment also suppressed tumor growth in implanted HT‑1080 cells in vivo. Using annexin V/propidium iodide staining and the detection of activated caspase 3, it was found that X‑ray irradiation increased the apoptotic rate of HT1080 cells and resulted in G2/M arrest. However, apoptosis in the HT1080 cells treated with 5 mM AsA remained unchanged, and no changes were observed in the G2/M fraction. By contrast, AsA treatment caused increased suppression of proliferation compared with X‑ray irradiation. These results suggested that 5 mM AsA slowed the cell cycle and reduced tumor growth. Therefore, X‑ray irradiation combined with AsA treatment may be effective against epithelial cancer and sarcoma cells.