Showing papers by "Badri N. Pandey published in 2008"

Thorium-induced oxidative stress mediated toxicity in mice and its abrogation by diethylenetriamine pentaacetate.

Abstract: Purpose: Thorium (232Th, IV) preferentially accumulates in the liver, femur and spleen, which necessitates evaluation of its toxic effect in these organs. The present study was aimed at evaluation of liver function, oxidative stress and histological alterations in these organs.Materials and methods: Swiss albino mice were administered either with Thorium nitrate (10 mg/kg body weight/day equivalent to 1090 pCi/kg body weight/day) for 30 days (1/40th dose of LD50/30; the dose of thorium required to kill 50% of the test cohort within 30 days) intraperitoneally or with calcium salt of diethylenetriamine pentaacetate (Ca-DTPA, 100 μmole/kg body/weight) intravenously or both. Liver function tests and oxidative damage was assessed. The concentration of Th in the tissues was determined by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) method.Results: Administration of Th prevented the increase in the body and liver weight and altered liver functions. Th treatment to mice showed a decrease in t...

Increased cytotoxicity by the combination of radiation and diospyrin diethylether in fibrosarcoma in culture and in tumor

Abstract: Objective: Radio-resistance in tumor cells and associated escape from apoptotic mechanism is a major problem in clinical cancer radiotherapy. Therefore, as a strategy to enhance the apoptosis, a combination of radiation and tumor-selective cytotoxic agents might improve the efficacy of treatment. Thus, the radiomodifying potential of diospyrin diethylether (D7), a plant-derived antitumor agent, was studied in fibrosarcoma tumor, both in vitro and in vivo.Material and methods: Mouse and human fibrosarcoma (Wehi164; HT1080) cells were treated with D7, alone, or in combination with radiation, for determination of cytotoxicity, clonogenic survival, and apoptotic death assays. Involvement of oxidative mechanism and nuclear factor kappa B (NF-κB) was studied in different treatment groups. In addition, fibrosarcoma-bearing mice were treated with D7 (intravenously, two doses, each of 1 mg/kg body weight) combined with radiation (two fractions of 2.5 Gy each) at appropriate intervals. The tumor volume was measured...

The involvement of cellular oxidative damage in the apoptotic death induced in γ-irradiated mouse thymocytes

Abstract: Radiation-induced cellular oxidative damage and the consequent apoptotic death were investigated in mouse thymocytes in the presence or absence of eugenol to understand the mechanism of modification in cellular radiosensitivity. The results showed the radiation-induced generation of intracellular Reactive Oxygen Species (ROS) in γ-irradiated thymocytes, which were detected within a low to moderate dose range of radiation exposure (sub cGy to 2 Gy) using 2′,7′-dichlorodihydrofluorescein diacetate (DCH-FDA) as a fluorescent probe. However, the dose response of the ROS generation was found to be different at low and high doses/rates, which was significantly inhibited when the cells were treated with eugenol. There was a decrease in the mitochondrial membrane potential (ΔΨmt) after the irradiation of cells, which was prevented when cells were pretreated with eugenol. The population of thymocytes with a reduced nuclear diameter was found to progressively increase with the post-irradiation incubation time following exposure to a dose of 5 Gy, which was, however, prevented in the thymocytes that were treated with eugenol. These results followed a pattern that is similar to the annexin-V method that was further verified in control and irradiated samples. We have found a correlation in cellular oxidative stress, a decrease in ΔΨmt and the induction of apoptotic cell death, suggesting the involvement of oxidative damage and alterations in the mitochondria in radiation-induced apoptosis in thymocytes.