Role of N-acetyl cysteine and acetyl-l-carnitine combination treatment on DNA-damage-related genes induced by radiation in HEI-OC1 cells.

PURPOSE: The aim of the present study was to evaluate the effect of acetyl-l-carnitine (ALC) and N-acetyl cysteine (NAC) on ionizing radiation (IR)-induced cytotoxicity and change in DNA damage-related genes in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells. METHODS: HEI-OC1 cells were irradiated with 5 Gy radiation and treated by eight combinations of NAC and/or ALC: control, NAC, ALC, IR, NAC + IR, ALC + NAC, ALC + IR, and ALC + NAC + IR. Cell viability, apoptotic cell death, and DNA damage were measured at the 72nd hour. Eighty-four IR-induced DNA-damage-related genes were determined by RT-PCR gene array and >10-fold changes were considered significant. RESULTS: IR decreased cell viability by about 50% at 72 hours of incubation. In particular, the ALC and/or NAC combination before IR protected the HEI-OC1 cells (p < .05). Single and combination treatment prior to IR led to lower apoptotic cell death (p < .05). There was a significant lower DNA damage in ALC + NAC + IR group compared to IR group (p < .05). Expressions of Brca2, Xpc, Mlh3, Rad51, Xrcc2, Hus1, Rad9a, Cdkn1a, Gadd45a which are the DNA-repair genes were found to be significantly higher in NAC + ALC + IR group than those in individual treatment of ALC or NAC. CONCLUSIONS: ALC and/or NAC treatment prior to IR led to higher cell viability and lower apoptotic cell damage compared to the IR group. The results of the study show that the ALC + NAC combination treatment inhibits DNA damage and induces DNA-repair genes to repair radiation damage, and this combination treatment is more effective against radiation-induced DNA damage than NAC or ALC therapy individually.

Effect of Ecklonia Cava Polyphenol Extract in House Ear Institute-Organ of Corti 1 Cells Against Cisplatin Ototoxicity: A Preliminary Study.

OBJECTIVE: Cisplatin is a widely used agent for the treatment of adult and childhood malignancies. Side effects such as nephrotoxicity, neurotoxicity, and ototoxicity lead to dose limitations. Ecklonia cava polyphenol extract (ECP) is a molecule obtained from algae that live in seawater in the Far East. ECP has recently been shown to have protective effects against oxidative stress. The aim of this study was to evaluate the possible protective effects of ECP on cisplatin ototoxicity. METHODS: In this study, we investigated the protective effects of ECP against cisplatin-induced cell death in mouse-derived House Ear Institute Organ of Corti (HEI-OC1) cochlear cells. Cisplatin (100 µM) and 1, 10, and 25 µM doses of ECP were administered to the cells, and the protective effects of ECP at 24 and 72 hours were investigated. Cell viability was evaluated by the WST-1 (water soluble tetrazolium salt). RESULTS: Cisplatin (100 µM) reduced cell viability in both the 24th and 72nd hour evaluation. Although the 25 µM dose of ECP showed otoprotective effects in the 24th hour, in the 72nd hour this effect disappeared. Other doses of ECP showed no otoprotective effects in the 24th and 72nd hours. CONCLUSION: Although ECP showed some protective effects in the 24th hour against cisplatin ototoxicity, these effects disappeared by the 72nd hour. Further studies using recurrent and higher doses of ECP are required.

Apoptotic Effects of Sanguinarine on the Organ of Corti 1 Cells: Comparison with Cisplatin.

OBJECTIVE: Sanguinarine is an alkaloid obtained from the root of Sanguinaria canadensis and other plants from the Papaveraceae family and is well known to possess a broad range of biological functions, such as antimicrobial, antifungal, anti-inflammatory, and antineoplastic activities. We aimed to specify the in vitro effect of sanguinarine on the House Ear Institute-Organ of Corti 1 (HEI-OC1) cells and to compare this effect with the ototoxic effect of cisplatin (CDDP). MATERIALS AND METHODS: We performed cell proliferation assay for determining the in vitro effect of sanguinarine alone and compared it with the effect of cisplatin. Flow cytometry annexin-V apoptosis detection was performed. RESULTS: We found that sanguinarine and CDDP inhibited the cell growth in a dose-dependant manner in HEI-OC1 cells after 24 h of incubation. In sanguinarine-treated group, apoptosis was 6.6%, necrosis was 26.7%, and the cell viability was 66.7%. Further, in CDDP-treated group, apoptosis was 5.6%, necrosis was 45.4%, and the cell viability was 48.7%. According to the annexin-V apoptosis detection results, we found that sanguinarine caused 3.9% apoptosis and 1.3% necrosis, while CDDP caused 2.9% apoptosis and 20% necrosis on HEI-OC1 cells. CONCLUSION: Our findings suggested that lower doses of sanguinarine are promising antineoplastic agents, which did not indicate any toxic effect on HEI-OC1 cells. Application of these data to clinical practice requires further support by in vivo studies.