Comparison of Cytotoxic and Ototoxic Effects of Lipoplatin and Cisplatin in Neuroblastoma In Vivo Tumor Model.

BACKGROUND: This study aimed to compare the cytotoxic, cytostatic, and ototoxic effects of lipoplatin compared to cisplatin application in the subcutaneous xenograft nude mouse neuroblastoma tumor model. METHODS: In this study, C1300 neuroblastoma cells were administered subcutaneously to 21 male nude mice. When the tumor reached 150 mm3 diameter, mice were randomized into 3 groups. Saline, cisplatin, and lipoplatin were given intraperitoneally. The auditory function tests were performed before administration and 72 hours after administration. Mice were sacrificed and the tumor and cochlea were removed after 72 hours. Histopathologic evaluation of necrosis and apoptosis was determined by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. Cyclooxygenase 2, superoxide dismutase 2, and inducible nitric oxide synthase levels were determined by immunohistochemistry in tissue samples. RESULTS: Apoptosis and necrosis rates were higher in lipoplatin group than in cisplatin group (P=.035 and P=.010, respectively) in tumor tissue. In the spiral ganglion, apoptosis and necrosis were lower in the lipoplatin group than in cisplatin group (P=.002 and P=.002, respectively). Cyclooxygenase 2 pattern in the cochlea was positive in both control and lipoplatin group and negative in cisplatin group (P=.001). Superoxide dismutase 2 and inducible nitric oxide synthase 2 protein expressions showed no difference between groups. The auditory functions were similar to baseline values and had a better threshold value in lipoplatin group than cisplatin group. CONCLUSION: For the treatment of neuroblastoma, the use of lipoplatin seems to be beneficial in reducing side effects of cisplatin. We recommend that the mechanism of these properties of lipoplatin should be evaluated in further studies.

Effect of Korean Red Ginseng on Noise-Induced Hearing Loss.

OBJECTIVE: Noise-induced hearing loss (NIHL) is one of the most important problems affecting both social and professional life of patients. There is no treatment method considered to be successful on the hearing loss that has become a permanent nature. Aim of this study is to evaluate protective effect of Korean Red Ginseng (KRG) against NIHL in an animal model. METHODS: Twenty-eight rats were separated into four groups [control saline (group I), control KRG (group II), saline + noise (group III), KRG + noise (group IV)]. Rats in the saline and KRG groups were fed via oral gavage with a dose of 200 mg/kg/day throughout for 10 days. Fourteen rats (group III and IV) were exposed to 4 kHz octave band noise at 120 dB SPL for 5 hours. Hearing levels of rats were evaluated by distortion product otoacoustic emissions (DPOAE) and auditory brainstem responses (ABR) at 4, 8, 12, 16 and 32 kHz frequencies prior to and on days 1, 7 and 10 after the noise exposure. Rats were sacrificed on 10th day, after the last audiological test. Cochlea and spiral ganglion tissues were evaluated by light microscopy. RESULTS: Audiological and histological results demonstrated that after noise the group IV showed better results than group III. In the noise exposed groups, the most prominent damage was seen at the 8 kHz frequency region than other regions. After the noise exposure, DPOAE responses were lost in 1st, 7th and 10th measurements in both group III and IV. Thus, we were not able to perform any statistical analyses for DPOAE results. CONCLUSION: Our findings suggest that KRG seems to be an efficient agent against NIHL. There is need for additional research to find out about the mechanisms of KRG's protective effect.