[Show abstract][Hide abstract] ABSTRACT: Aim:
To investigate the potential of the anti-oxidant ascorbic acid glucoside (AA-2G) to modulate neurotoxicity induced by high doses of nitrotriazole radiosensitizer.
Materials and methods:
Male and female C56Bl/6xCBA hybrid mice aged 8-14 weeks (weight 18-24 g) were used. Nitrotriazole drug radiosensitizer sanazole at a high dose of 2, 1 g/kg was per os administered to induce neurotoxicity at mice. Ascorbic acid glucoside was given 30 min before the sanazole administration. Serum ascorbic acid, brain glutathione level, as well as behavioral performance using open field apparatus were measured.
Administration of high (non-therapeutic) doses of the nitrotriazole drug sanazole results in neurotoxicity in mice as evidenced from behavioral performance, emotional activity and depletion of the cellular antioxidant, glutathione, in the brain. The serum levels of ascorbic acid was also found reduced in high dose sanazole treated animals. Per os administration of ascorbic acid glucoside significantly reduced the neurotoxicity. This effect was associated with the prevention of glutathione depletion in mouse brain and restoring the ascorbic acid level in serum.
Administration of ascorbic acid glucoside, but not ascorbic acid, before sanazole administration protected from sanazole-induced neurotoxicity by preventing the decrease in the brain reduced glutathione level and providing high level of ascorbic acid in plasma.
Full-text · Article · Jul 2013 · Journal of cancer research and therapeutics
[Show abstract][Hide abstract] ABSTRACT: Silver nanoparticles were prepared from silver nitrate using a vitamin C derivative, 6-palmitoyl ascorbic acid-2-glucoside (PAsAG), via a sonochemical experiment. The resultant golden yellow solution that contained silver nanoparticle-PAsAG complex (SN-PAsAG) of about 5 nm particle sizes was explored for its potential to offer protection to DNA from γ-radiation-induced damages. The presence of SN-PAsAG during irradiation inhibited the disappearance of covalently closed circular (ccc) form of plasmid pBR322 with a dose modifying factor of 1.78. SN-PAsAG protected cellular DNA from radiation-induced damage as evident from comet assay study on mouse spleen cells, irradiated ex vivo. When orally administered with SN-PAsAG at 1 hour prior to whole-body radiation exposure, cellular DNA was found protected from radiation-induced strand breaks in various tissues (spleen cells, bone marrow cells, and blood leucocytes) of animals. Also, SN-PAsAG could enhance the rate of repair of cellular DNA in blood leucocytes and bone marrow cells when administered immediately after radiation exposure. The studies, under in vitro, ex vivo, and in vivo radiation exposure conditions, showed effective radiation protection.
[Show abstract][Hide abstract] ABSTRACT: Whole-body exposure of mice to gamma radiation leads to depletion of tissue antioxidant defence and damages the haematopoietic and gastrointestinal systems in mice. Administration of ascorbic acid-2-glucoside (AsAG) at a dose of 100 mg/kg body weight could prevent the radiation-induced reduction of total White Blood Cell (WBC) count and decrease in bone marrow viability following whole-body radiation. An enhanced spleen colony formation was also observed in whole-body irradiated mice administered with AsAG. Administration of AsAG also protected the epithelial cells of the gastrointestinal tract from the radiation-induced structural alterations. The generation of Reactive Oxygen Species (ROS) in tissues due to radiation exposure depletes the antioxidant defence systems and increase the peroxidative damage to membrane lipids, and the administration of AsAG prior to irradiation protected the tissue antioxidant system and membrane lipids from the radiation-induced damage.
No preview · Article · Nov 2010 · International Journal of Low Radiation
[Show abstract][Hide abstract] ABSTRACT: The effects of TMG [2-(alpha-d-glucopyranosyl) methyl-2,5,7,8-tetramethylchroman-6-ol], a water-soluble vitamin E derivative, administered after irradiation on the mortality of X-irradiated mice and on the development of tumors in the mammary and pituitary glands in rats were investigated. When TMG (650 mg/kg) was administered intraperitoneally (i.p.) to C3H mice immediately after whole-body exposure to 7 Gy radiation, the 30-day survival was significantly higher than that of the control mice. The i.p. administration of TMG at 4 h after irradiation significantly improved survival compared to that of the controls, but administration 8 h after irradiation did not have a significant effect. Subcutaneous administration of TMG immediately after irradiation also decreased mortality significantly. When dams of lactating Wister rats were exposed to 1.5 Gy of X rays at day 21 after parturition and were then treated with diethylstilbestrol as a tumor promoter, the incidence of mammary tumors and pituitary tumors was increased compared to that in the nonirradiated control group. The administration of TMG (600 mg/kg, i.p.) after irradiation significantly reduced the incidence of mammary tumors and pituitary tumors. The number of rats that were free of both mammary and pituitary gland tumors was enhanced fourfold by TMG. These results suggest that TMG is effective in preventing radiation-induced bone marrow death in mice and in reducing mammary and pituitary tumors in rats even when it is administered after irradiation.
No preview · Article · Oct 2009 · Radiation Research
[Show abstract][Hide abstract] ABSTRACT: A palmitoyl derivative of ascorbic acid 2-glucoside, 6-palmitoyl ascorbic acid-2-glucoside (PAsAG), which possess good antioxidant properties, is examined for radioprotection in vitro, ex vivo and in vivo models. PAsAG protected plasmid DNA from gamma-radiation induced damages under in vitro conditions. Presence of 1.6 mM PAsAG inhibited the disappearance of ccc (covalently closed circular) form of plasmid pBR322 with a dose modifying factor of 1.5. Comet assay studies on mouse spleen cells exposed to 6 Gy gamma-radiation (ex vivo) in presence and absence of PAsAG revealed that cellular DNA was effectively protected by this compound from radiation induced damages. Oral administration of 80 mg/kg body weight of PAsAG to mice 1 hour prior to 6 Gy whole body gamma-radiation exposure, efficiently protected cellular DNA in tissues such as spleen, bone marrow and blood, from radiation induced damages as indicated by alkaline comet assay. Oxidative stress in tissues such as liver and brain of mice, following whole body exposure to various doses of gamma-radiation (2-8 Gy), monitored as levels of GSH and peroxidation of lipids, were found considerably reduced when PAsAG was orally administered (80 mg/kg body weight) to the mice one hour prior to the radiation exposure. PAsAG administration improved the per cent survival of mice following exposure to 10 Gy whole body gamma-radiation. Thus PAsAG could act as a radioprotector under in vitro, ex vivo and in vivo conditions of ionizing-radiation exposure.
No preview · Article · May 2009 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: Cisplatin is one of the most widely used cytotoxic therapeutic agents for the treatment of cancer. This drug, at effective higher doses, causes many physiological adverse effects such as nephrotoxicity and genotoxicity. The toxicity of the drug has been attributed to the induction of oxidative free radicals.
Following intraperitoneal administration of cisplatin and ascorbic acid monoglucoside (AsAG) or alpha-tocopherol monoglucoside (TMG), investigations were conducted on levels of serum urea and creatinine, peroxidation of lipids in renal tissues, renal antioxidants and histopathology of renal tissue.
Administration of cisplatin to mice induced a marked renal failure, characterized by significant increase in serum urea and creatinine levels in addition to severe alterations in renal tissue architecture. Cisplatin also induced oxidative stress as indicated by increased lipid peroxidation and decreased levels of reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase in renal tissues. Administration of AsAG or TMG markedly reduced the cisplatin-induced higher plasma creatinine and urea levels and counteracted the deleterious effects of cisplatin on oxidative stress markers and protected the tissues from the cisplatin-induced lipid peroxidation.
These results indicated that AsAG or TMG has a protective effect against cisplatin-induced renal damage in mice. The protection is mediated by preventing the decline of antioxidant status. The results have implications in use of AsAG or TMG in human application for protecting against drug-induced nephrotoxicity.
No preview · Article · Sep 2008 · Experimental and Toxicologic Pathology
[Show abstract][Hide abstract] ABSTRACT: In vivo radioprotection of C3H mice by i.p. administration of Zn-, Mn-, Cu-, or Se-containing heat-treated Saccharomyces serevisiae yeast sample was examined. The 30-day survival of the group treated 30 min before 7.5 Gy whole-body X-irradiation with mineral-containing yeast powders suspended in 0.5% methylcellulose was significantly higher than that of control group. When mineral-yeast was administered immediately after irradiation, the survival rate was even higher and Zn- or Cu-yeast showed the highest rate (more than 90%). Although treatment with simple yeast showed a high survival rate (73%), it was significantly lower than that obtained by the Zn-yeast treatment. The effects of Zn-yeast were studied further. When the interval between irradiation and administration was varied, the protective activity of Zn-yeast decreased gradually by increasing the interval but was still significantly high for the administration at 10 h post-irradiation. The dose reduction factor of Zn-yeast (100 mg/kg, i.p. administration immediately after irradiation) was about 1.2. When the suspension of Zn-yeast was fractionated by centrifugation, the insoluble fraction showed a potent effect, while the soluble fraction had only a moderate effect. In conclusion, mineral-yeast, especially Zn-yeast, provides remarkable post-irradiation protection against lethal whole body X-irradiation. The activity is mainly attributable to the insoluble fraction, whereas some soluble components might contribute to the additional protective activity.
No preview · Article · Aug 2008 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: Effects of ascorbic acid (AA), ascorbic acid glycoside (AAG) and alpha-tocopherol monoglycoside (TMG) on radiation - and H(2)O(2)-induced decomposition of thymine in aqueous solutions were investigated. Of the three compounds studied, AAG was found to possess the most marked protector properties. An explanation of this phenomenon has been given in terms of differences in molecular structures of AA and AAG, as well as properties of radical adducts formed during their interaction with OH radicals.
No preview · Article · Aug 2008 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: Thymine/Radiolysis/Radical/Vitamine Glycosides. Effects of ascorbic acid (AA), ascorbic acid glycoside (AAG) and (X-tocopherol monoglycoside (TMG) on radiation - and H2O2-induced decomposition of thymine in aqueous solutions were investigated. Of the three compounds studied, AAG was found to possess the most marked protector properties. An explanation of this phenomenon has been given in terms of differences in molecular structures of AA and AAG, as well as properties of radical adducts formed during their interaction with OH radicals.
No preview · Article · Jul 2008 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: Ascorbic acid monoglucoside (AsAG), a glucoside derivative of ascorbic acid, has been examined for its antioxidant and radioprotective abilities. AsAG neutralized 1, 1 diphenyl -2-picryl-hydrazyl (DPPH), a stable free radical in a concentration dependent manner thus indicating its antioxidant ability. AsAG protected mice liver tissues in vitro from peroxidative damage in lipids (measured as TBARS) resulting from 25Gy gamma irradiation. It also protected plasmid pBR322 DNA from gamma-radiation induced strand breaks as evidenced from studies on agarose gel electrophoresis of the plasmid DNA after radiation exposure. Oral administration of AsAG to mice prior to whole body gamma radiation exposure (4Gy) resulted in a reduction of radiation induced lipid peroxides in the liver tissue indicating in vivo radiation protection of membranes. Pulse radiolysis studies indicated that AsAG offered radioprotection by scavenging free radicals. The rate constants for the reactions OH and N(3) radicals with AsAG were determined to be 6.4 x 10(9) dm(3) mol(-1) s(-1) and 2.3 x 10(9) dm(3) mol(-1) s(-1), respectively at pH 7. It was observed that AsAG radicals undergo conjugation as the pH of the solution is raised to 11 in the case of a one-electron oxidation reaction. As the OH(*) radical adds to the ring, the conjugation effect starts appearing at pH 10.
No preview · Article · Oct 2007 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: Damage to cellular DNA and its repair in the peripheral blood leucocytes of mice exposed to 4 Gy whole-body gamma-radiation was studied by alkaline single cell gel electrophoresis or comet assay. The comet parameters of DNA, such as comet tail length, % of DNA in tail, tail moment and olive tail moment, were found increased in the leucocytes from irradiated animals due to radiation-induced DNA strand breaks. The strand breaks in cellular DNA were repaired in a time dependent manner as evidenced from the decrease in the comet parameters. Thus, 15 minutes after irradiation exposure, 15% of DNA strand breaks were repaired and at 90 minutes post-irradiation, 43% were repaired. When tocopherol monoglucoside was administered to mice following radiation, it was found that at 15 and 90 minutes post-irradiation, 64% and 67% DNA, respectively, were repaired. This would suggest that administration of tocopherol monoglucoside enhanced the repair of cellular DNA damage in whole-body irradiated mice. However, in vitro studies, either with humans or mice, peripheral blood leucocytes showed that the presence of tocopherol monoglucoside (0.5 mM) in post-irradiation incubation medium did not enhance the repair of DNA strand breaks.
No preview · Article · Jan 2007 · International Journal of Low Radiation
[Show abstract][Hide abstract] ABSTRACT: The formation of products resulting from the O-glycoside bond cleavage following radiolysis of aqueous solutions of methyl-alpha-D-glucopyranoside (I), 3-O-methyl-alpha-D-glucopyranose (II), maltose, lactose, gentiobiose and cellobiose were studied. Radiation-induced destruction yields were also determined for dextran, laminarin and trimethylcelulose upon irradiation of their aqueous solutions. Oxygen, quinones and compounds capable of forming quinoid structures were found to inhibit radiation-induced homolytic destruction processes taking place in glycosides, di- and polysaccharides. The data obtained in this study enabled the authors to demonstrate an important role played by the fragmentation reaction of C-2 radicals which were generated from the starting substances in the formation of final radiolysis products.
No preview · Article · Oct 2005 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: AK-2123, a nitrotriazole hypoxic cell sensitizer has reportedly improved results in head and neck cancers, uterine cervical cancers and other solid tumours when added to radical radiotherapy. A prospectively randomised trial was initiated by the International Atomic Energy Agency (IAEA) evaluating AK-2123 and radiotherapy in treatment of uterine cervical cancer stage IIIA and IIIB.
A total of 333 patients were randomised between May 1995 and December 1998. Patients were randomised to either standard radical treatment (radiation therapy alone, RT) or standard radical radiotherapy and additional administration of AK-2123 (RT+AK-2123). The total dose of 45-50.8 Gy was delivered in 20 to 28 fractions over 4 to 5 1/2 weeks. The dose to the central disease was escalated to a radiobiologically equivalent dose of 70 Gy by external beam or brachytherapy, in accordance with each centres individual practice. In the study arm, patients received 0.6 g/sqm AK-2123 by intravenous administration before external beam radiotherapy, treating with AK-2123 on alternate days (e.g. Monday-Wednesday-Friday) during the entire course of external beam therapy.
After a median follow up of 57 months (range 30-73 months) the rate of local tumour control was significantly higher in the group who received radiotherapy and additional administration of AK-2123. Local tumour control at the last follow up was 61% after combined radiotherapy and AK-2123 and 46% after radiotherapy alone (p = 0.005). AK-2123 neither increased gastro-intestinal toxicity nor gave any haematological toxicity. A mild peripheral neuropathy (Grade 1:11% and Grade 2:3%) was seen infrequently after AK-2123 administration and was usually completely reversible. Crude survival rates were 41% after radical treatment compared to 57% after combined therapy (p = 0.007).
We conclude that the addition of AK-2123 to radical radiotherapy significantly increases response rates and local tumour control in advanced squamous cell cancer of the uterine cervix without any increase in major toxicity. Further analysis and follow up are needed to evaluate if this benefit will translate into prolonged survival. We strongly suggest that our initially very promising study should lead other centres to further studies of AK-2123 in randomised clinical trials.
No preview · Article · Apr 2005 · Journal of cancer research and therapeutics
[Show abstract][Hide abstract] ABSTRACT: A preparation of alpha-tocopherol monoglucoside (TMG) administered i.p. at a dose of 600 mg/kg immediately after whole body gamma irradiation was examined for its radioprotective efficacy towards bone marrow and peripheral blood nucleated cells. When mice received X-rays at a dose of 5,6 Gy, a marked decrease in bone marrow karyocytes and a reduction of peripheral leukocytes within the early post-irradiated period were observed. However these changes were attenuated in TMG-treated mice. Significant protection of blood lymphocytes was found for the TMG group of mice. The return to normal value of the reduced blood leukocyte count starting from the 8th day was more rapid in TMG-treated mice than in untreated irradiated mice. TMG administration was found to enhance hematopoietic recovery, as measured by the exceeded nucleated bone marrow cell count due to elevated amount of both lymphoid and granulocytic elements in the TMG-group, in comparison with that of both control irradiated and non-irradiated animals. These findings indicate that the radioprotective effect of TMG is apparently realized through its influence on hematopoietic system.
No preview · Article · Apr 2005 · Journal of Radiation Research
[Show abstract][Hide abstract] ABSTRACT: In this work we investigated the ability of hypoxia-selective radiosensitizer--sanazole to produce nitric oxide (NO).
NO formation was determined by spectophotometric method in the reaction with sanazole and oxyhemoglobin. In suspensions of lymphoma EL-4 and mastocytoma P 8815 cell NO production was estimated indirectly as nitrite concentration in the supernatant fraction.
Transformation of oxyhemoglobin by sanazole to methemoglobin suggested the dissociation of nitro group in aqueous solution and denitration of molecules. Addition of sanazole to hypoxic tumor cell suspension resulted in the increase of nitrite content in tissue culture medium.
Presented data suggest the ability of sanazole to produce NO that may be important in a probable mechanism for antitumor and immunomodulating properties of this radiosensitizer.
Full-text · Article · Jan 2005 · Experimental oncology
[Show abstract][Hide abstract] ABSTRACT: Study of antioxidant properties of tocopherol monoglucoside (TMG), a water-soluble Vitamin E derivative, by differential pulse voltammetry has been carried out in this work. The pH influence on the antioxidant properties of TMG has been also investigated. It was observed that the antioxidant activity of TMG is greater at 6.90<pH<9.18. The reactions between the TMG and reactive oxygen species have been considered. Antioxidant activity of some standard antioxidants including Vitamin E was given for comparison. The results indicate that the TMG is an effective antioxidant in neutral solutions. The oxidation potential for TMG at pH 7.31 has been found (E=0.55+/-0.03V versus Ag|AgCl|KCl(sat) electrode). Finally the use of TMG for protection against oxidative stress has been recommended.
[Show abstract][Hide abstract] ABSTRACT: Radioprotective compounds are of importance in clinical radiation therapy, because normal tissues should be protected against radiation injury while using higher doses of radiation to obtain better cancer control. We investigated the radioprotection of cellular DNA in cancer and in various cells and tissues, in a murine system following exposure to gamma-radiation and tocopherol monoglucoside (TMG) administration. We used single-cell gel electrophoresis (comet assay) and studied the progression of murine fibrosarcoma following radiation exposure and administration of TMG. The administration of TMG to tumor-bearing mice protected the cellular DNA against radiation-induced strand breaks as shown by the decrease in comet tail length, tail moment, and percentage of DNA in the tails of the cells of normal tissues. The same parameters were not altered in the cells of fibrosarcoma. Our results showed that the administration of TMG immediately after exposure to gamma-radiation can protect normal tissues against radiation damages in tumor-bearing mice. Local gamma-radiation exposure (5 Gy) of the tumor retarded the tumor growth. Administration of TMG did not protect cancer cells from radiation damage because the growth curves of cancer cells treated with radiation alone and those treated with TMG after irradiation were not significantly different.
No preview · Article · Feb 2004 · Journal of Environmental Pathology Toxicology and Oncology