Evaluation and optimization of radioprotective activity of Coronopus didymus Linn. in γ-irradiated mice

K.R. Prabhakar, V.P. Veerapur, K.V. Parihar, K.I. Priyadarsini, B.S.S. Rao, M.K. Unnikrishnan

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Purpose: To evaluate and optimize the radioprotective ability of the most potent fraction of an aqueous extract of Coronopus didymus in whole body γ-irradiated Swiss albino mice and to evaluate the antioxidant status and lipid peroxidation of the livers of the surviving mice. To correlate the free radical scavenging studies with in vivo radioprotection ability. Materials and methods: Swiss albino mice were treated with either vehicle or the different doses of extract/fraction suspension by an i.p. route, 30 min before exposure to 10 Gy γ-irradiation and the animals were monitored twice daily for any signs of radiation toxicity and mortality. Radiation dose response (7-11 Gy), optimization of route, time of drug administration and evaluation of dose response factor (DRF) at the best dose of the fraction was studied. Endogenous antioxidant status and lipid peroxidation of the livers of the mice surviving on the 31st day was evaluated by using spectrophotometric methods. Results: The most active free radical scavenging fraction (CDF1) as assessed by competition kinetic studies using pulse radiolysis showed maximum in vivo radioprotection of 70% at a dose of 400 mg/kg body weight (bw) compared to corresponding 10 Gy irradiated control. Optimum radioprotection was observed upon i.p. administration, 30 min prior to 10 Gy irradiation and DRF at a dose of 400 mg/kg bw for 30 day survival was found to be 1.07. The levels of endogenous antioxidant enzymes and lipid peroxidation in the CDF1 treated surviving mice were found to reverse back to their normal levels. Conclusions: The optimum dose, time and route of drug administration for maximum radioprotection by CDF1 were determined. The reversal of the levels of endogenous antioxidant enzymes and lipid peroxidation indicates reduced oxidative stress in CDF1 treated surviving mice. © 2006 Informa UK Ltd.
Original languageEnglish
Pages (from-to)525-536
Number of pages12
JournalInternational Journal of Radiation Biology
Volume82
Issue number8
DOIs
Publication statusPublished - 2006

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Lipid Peroxidation
Antioxidants
Free Radicals
Pulse Radiolysis
Body Weight
Drug Administration Routes
Radiation
Drug Evaluation
Liver
Enzymes
Suspensions
Oxidative Stress
Mortality

Cite this

Prabhakar, K.R. ; Veerapur, V.P. ; Parihar, K.V. ; Priyadarsini, K.I. ; Rao, B.S.S. ; Unnikrishnan, M.K. / Evaluation and optimization of radioprotective activity of Coronopus didymus Linn. in γ-irradiated mice. In: International Journal of Radiation Biology. 2006 ; Vol. 82, No. 8. pp. 525-536.
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title = "Evaluation and optimization of radioprotective activity of Coronopus didymus Linn. in γ-irradiated mice",
abstract = "Purpose: To evaluate and optimize the radioprotective ability of the most potent fraction of an aqueous extract of Coronopus didymus in whole body γ-irradiated Swiss albino mice and to evaluate the antioxidant status and lipid peroxidation of the livers of the surviving mice. To correlate the free radical scavenging studies with in vivo radioprotection ability. Materials and methods: Swiss albino mice were treated with either vehicle or the different doses of extract/fraction suspension by an i.p. route, 30 min before exposure to 10 Gy γ-irradiation and the animals were monitored twice daily for any signs of radiation toxicity and mortality. Radiation dose response (7-11 Gy), optimization of route, time of drug administration and evaluation of dose response factor (DRF) at the best dose of the fraction was studied. Endogenous antioxidant status and lipid peroxidation of the livers of the mice surviving on the 31st day was evaluated by using spectrophotometric methods. Results: The most active free radical scavenging fraction (CDF1) as assessed by competition kinetic studies using pulse radiolysis showed maximum in vivo radioprotection of 70{\%} at a dose of 400 mg/kg body weight (bw) compared to corresponding 10 Gy irradiated control. Optimum radioprotection was observed upon i.p. administration, 30 min prior to 10 Gy irradiation and DRF at a dose of 400 mg/kg bw for 30 day survival was found to be 1.07. The levels of endogenous antioxidant enzymes and lipid peroxidation in the CDF1 treated surviving mice were found to reverse back to their normal levels. Conclusions: The optimum dose, time and route of drug administration for maximum radioprotection by CDF1 were determined. The reversal of the levels of endogenous antioxidant enzymes and lipid peroxidation indicates reduced oxidative stress in CDF1 treated surviving mice. {\circledC} 2006 Informa UK Ltd.",
author = "K.R. Prabhakar and V.P. Veerapur and K.V. Parihar and K.I. Priyadarsini and B.S.S. Rao and M.K. Unnikrishnan",
note = "Cited By :30 Export Date: 10 November 2017 CODEN: IJRBA Correspondence Address: Unnikrishnan, M.K.; Manipal College of Pharmaceutical Sciences, Manipal-576 104, Karnataka, India; email: mkunnikrishnan@gmail.com Chemicals/CAS: Plant Extracts; Radiation-Protective Agents References: Keck, A.-S., Finley, J.W., Cruciferous vegetables: Cancer protective mechanisms of glucosinolate hydrolysis products and selenium (2004) Integrative Cancer Therapies, 3, pp. 5-12; Arora, R., Gupta, D., Chawla, R., Sagar, R., Sharma, A., Kumar, R., Prasad, J., Sharma, R.K., Radioprotection by plant products: Present status and future prospects (2005) Phytotherapy Research, 19, pp. 1-22; Barcellos-Hoff, M.H., Park, C., Wright, E.G., Radiation and the microenvironment - Tumorigenesis and therapy (2005) Nature Reviews - Cancer, 58, pp. 867-875; Braughler, J.M., Chase, R.L., Pregenzer, J.F., Oxidation of ferrous iron during peroxidation of various lipid substrates (1987) Biochimica Biophysica Acta, 921, pp. 457-464; Claiborne, A., (1985) Handbook of Methods for Oxygen Radical Research, , London: CRC Press; Clardy, J., Walsh, C., Lessons from natural molecules (2004) Nature, 432, pp. 829-837; De Ruiz, R.E.L., Fusco, M., Sosa, A., Ruiz, S.O., Constituents of Coronopus didymus (1994) Fitoterpia, 65, pp. 181-182; Fusco, M.R.R., De Ruiz, R.E.L., Sosa, A., Ruiz, O.S., Isolation of sterols, oleanolic acid and flavonoids from Coronopus didymus Sm. (Brassicaceae) (2000) Acta Farmaceutica Bonaerense, 19, pp. 273-276; Gelvan, D., Saltman, P., Different cellular targets of Cu- and Fe-catalyzed oxidation observed using a Cu-compatible thiobarbiturate acid assay (1990) Biochimica Biophysica Acta, 1035, pp. 353-360; Ghosh, M.N., (1984) Fundamentals of Experimental Pharmacology, 2nd Ed., , Calcutta, India: Scientific Book Agency; Giusti, M., Raimondi, M., Ravagnan, G., Sapora, O., Parasassi, T., Human cell membrane oxidative damage induced by single and fractionated doses of ionizing radiation: A fluorescence spectroscopy study (1998) International Journal of Radiation Biology, 74, pp. 595-605; Habig, W.H., Pabst, M.J., Jarkoby, W.B., Glutathione S-transferases. The first enzymatic step in mercapturic acid formation (1974) Journal of Biological Chemistry, 249, pp. 7130-7139; Inam Ul Haque, Composition of essential oil of Coronopus didymus seeds (1989) Journal of Chemical Society of Pakistan, 11, pp. 80-81; Lowry, O.H., Rosenhrough, N.J., Farr, A.L., Randall, R.J., Protein measurement with the Folin phenol reagent (1951) Journal of Biological Chemistry, 193, pp. 265-275; MacVittie, T.J., Weiss, J.F., Browne, D., (1996) Advances in the Treatment of Radiation Injuries, , Oxford: Pergamon Press; McDowall, F.H., Mortan, I.D., McDowell, A.K.R., Land-cress taint in cream and butter (1947) New Zealand Journal of Science and Technology, A28, pp. 305-307; Mishra, B., Priyadarsini, K.I., Sudheer Kumar, M., Unnikrishnan, M.K., Effect of O-glycosilation on the antioxidant activity and free radical reactions of a plant flavonoid, Chrysoeriol (2003) Bioorganic Medicinal Chemistry, 11, pp. 2677-2685; Misra, H.P., Fridovich, I., The role of superoxide anion in the autoxidation of epinephrine and a simple assay for superoxide dismutase (1972) Journal of Biological Chemistry, 247, pp. 3170-3175; Monig, H., Messerschmidt, O., Streffer, C., Chemical radio-protection in mammals and in man (1990) Radiation Exposure and Occupational Risks, pp. 97-143. , Scherer E, Streffer C, Trott K-R, editors. Berlin: Springer-Verlag; Moran, A., DePierre, J.W., Mannervick, B., Levels of glutathione, glutathione reductase, glutathione-S-transferase activities in rat liver (1979) Biochimica Biophysica Acta, 582, pp. 67-68; Nomura, T., Yamaoka, K., Sakai, K., Elevation of antioxidants in the kidneys of mice by low-dose irradiation and its effect on Fe3+-NTA-induced kidney damage (2002) International Congress Series, 1236, pp. 481-485; Onyilagha, J., Bala, A., Hallett, R., Gruber, M., Soroka, J., Westcott, N., Leaf flavonoids of the cruciferous species, Camelina sativa, Crambe spp., Thlaspi arvense and several other genera of the family Brassicaceae (2003) Biochemical Systematics and Ecology, 31, pp. 1309-1322; Parasassi, T., Giusti, A.M., Gratton, E., Monaco, E., Raimondi, M., Ravagnan, G., Sapora, O., Evidence for an increase in water concentration in bilayers after oxidative damage of phospholipids induced by ionizing radiation (1994) International Journal of Radiation Biology, 65, pp. 329-334; Paris, F., Fuks, Z., Kang, A., Capodieci, P., Juan, G., Ehleiter, D., Haimovitz-Friedman, A., Kolesnick, R., Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice (2001) Science, 293, pp. 293-297; Prabhakar, K.R., Srinivasan, K.K., Padma, G.M.R., Chemical investigation, anti-inflammatory and wound healing properties of Coronopus didymus (2002) Pharmaceutical Biology, 40, pp. 490-493; Prabhakar, K.R., Veeresh, V.P., Vipan Kumar, P., Sudheer Kumar, M., Priyadarshini, K.I., Rao, B.S.S., Unnikrishnan, M.K., Bioactivity guided fractionation of Coronopus didymus Linn: A Free radical scavenging perspective Phytomedicine, , (In press) doi: 10.1016/j.phymed.2005.07.003; Priyadarshini, K.I., Naik, D.B., Moorthy, P.N., Mittal, J.P., (1995) Proceedings of the 7th Tihany Symposium on Radiation Chemistry, p. 105. , Bhabha Atomic Research Center, Trombay, Mumbai, India; Raskin Ribnicky, D.M., Komarnytsky, S., Ilic, N., Poulev, A., Borisjuk, N., Brinker, A., Moreno, D.A., Fridlender, B., Plants and human health in the twenty-first century (2002) TRENDS in Biotechnology, 20, pp. 522-532; Robert, J.W., Spencer, J.P.E., Rice-Evans, C., Serial review: Flavonoids and isoflavones (phytoestrogens): Absorption, metabolism, and bioactivity (2004) Free Radical Biology and Medicine, 36, pp. 838-849; Sedlak, J., Lindsay, R., Estimation of total, protein-bound, and nonprotein sulfhydryl groups in tissue with Ellman's reagent (1968) Analytical Biochemistry, 25, pp. 192-205; Springfield, E.P., Eagles, P.K.F., Scott, G., Quality assessment of South African herbal medicines by means of HPLC finger-printing (2005) Journal of Ethnopharmacology, 101, pp. 75-83; Tannehill, S.P., Mehta, M.P., Amifostine and radiation therapy: Past, present, and future (1996) Seminars in Oncology, 23 (SUPPL. 8), pp. 69-77; Uma Devi, P., Normal tissue protection in cancer therapy: Progress and prospects (1998) Acta Oncologica, 37, pp. 247-252; Uma Devi, P., Ganasoundari, A., Rao, B.S.S., Srinivasan, K.K., In vivo radioprotection by ocimum flavanoids: Survival of mice (1999) Radiation Research, 151, pp. 74-78; Verhoeven, D.T., Goldbohm, R.A., Van Poppel, G., Epidemiological studies on Brassica vegetables and cancer risk (1996) Cancer Epidemiology Biomarkers & Prevention, 5, pp. 733-748; Weiss, J.F., Landauer, M.R., Protection against ionizing radiation by antioxidant nutrients and phytochemicals (2003) Toxicology, 189, pp. 1-20; Weiss, J.F., Pharmacological approaches to protection against radiation-induced lethality and other damage (1997) Environmental Health Perspective, 105 (SUPPL. 6), pp. 1473-1478; Willson, R.L., Free radical repair mechanisms and the interaction of glutathione, Vit C and Vit E (1983) Radioprotectors and Anticarcinogens, pp. 1-22. , Nygaard OF, Simic MG, editors. New York: Academic Press",
year = "2006",
doi = "10.1080/09553000600876686",
language = "English",
volume = "82",
pages = "525--536",
journal = "International Journal of Radiation Biology",
issn = "0955-3002",
publisher = "Informa Healthcare",
number = "8",

}

Evaluation and optimization of radioprotective activity of Coronopus didymus Linn. in γ-irradiated mice. / Prabhakar, K.R.; Veerapur, V.P.; Parihar, K.V.; Priyadarsini, K.I.; Rao, B.S.S.; Unnikrishnan, M.K.

In: International Journal of Radiation Biology, Vol. 82, No. 8, 2006, p. 525-536.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Evaluation and optimization of radioprotective activity of Coronopus didymus Linn. in γ-irradiated mice

AU - Prabhakar, K.R.

AU - Veerapur, V.P.

AU - Parihar, K.V.

AU - Priyadarsini, K.I.

AU - Rao, B.S.S.

AU - Unnikrishnan, M.K.

N1 - Cited By :30 Export Date: 10 November 2017 CODEN: IJRBA Correspondence Address: Unnikrishnan, M.K.; Manipal College of Pharmaceutical Sciences, Manipal-576 104, Karnataka, India; email: mkunnikrishnan@gmail.com Chemicals/CAS: Plant Extracts; Radiation-Protective Agents References: Keck, A.-S., Finley, J.W., Cruciferous vegetables: Cancer protective mechanisms of glucosinolate hydrolysis products and selenium (2004) Integrative Cancer Therapies, 3, pp. 5-12; Arora, R., Gupta, D., Chawla, R., Sagar, R., Sharma, A., Kumar, R., Prasad, J., Sharma, R.K., Radioprotection by plant products: Present status and future prospects (2005) Phytotherapy Research, 19, pp. 1-22; Barcellos-Hoff, M.H., Park, C., Wright, E.G., Radiation and the microenvironment - Tumorigenesis and therapy (2005) Nature Reviews - Cancer, 58, pp. 867-875; Braughler, J.M., Chase, R.L., Pregenzer, J.F., Oxidation of ferrous iron during peroxidation of various lipid substrates (1987) Biochimica Biophysica Acta, 921, pp. 457-464; Claiborne, A., (1985) Handbook of Methods for Oxygen Radical Research, , London: CRC Press; Clardy, J., Walsh, C., Lessons from natural molecules (2004) Nature, 432, pp. 829-837; De Ruiz, R.E.L., Fusco, M., Sosa, A., Ruiz, S.O., Constituents of Coronopus didymus (1994) Fitoterpia, 65, pp. 181-182; Fusco, M.R.R., De Ruiz, R.E.L., Sosa, A., Ruiz, O.S., Isolation of sterols, oleanolic acid and flavonoids from Coronopus didymus Sm. (Brassicaceae) (2000) Acta Farmaceutica Bonaerense, 19, pp. 273-276; Gelvan, D., Saltman, P., Different cellular targets of Cu- and Fe-catalyzed oxidation observed using a Cu-compatible thiobarbiturate acid assay (1990) Biochimica Biophysica Acta, 1035, pp. 353-360; Ghosh, M.N., (1984) Fundamentals of Experimental Pharmacology, 2nd Ed., , Calcutta, India: Scientific Book Agency; Giusti, M., Raimondi, M., Ravagnan, G., Sapora, O., Parasassi, T., Human cell membrane oxidative damage induced by single and fractionated doses of ionizing radiation: A fluorescence spectroscopy study (1998) International Journal of Radiation Biology, 74, pp. 595-605; Habig, W.H., Pabst, M.J., Jarkoby, W.B., Glutathione S-transferases. The first enzymatic step in mercapturic acid formation (1974) Journal of Biological Chemistry, 249, pp. 7130-7139; Inam Ul Haque, Composition of essential oil of Coronopus didymus seeds (1989) Journal of Chemical Society of Pakistan, 11, pp. 80-81; Lowry, O.H., Rosenhrough, N.J., Farr, A.L., Randall, R.J., Protein measurement with the Folin phenol reagent (1951) Journal of Biological Chemistry, 193, pp. 265-275; MacVittie, T.J., Weiss, J.F., Browne, D., (1996) Advances in the Treatment of Radiation Injuries, , Oxford: Pergamon Press; McDowall, F.H., Mortan, I.D., McDowell, A.K.R., Land-cress taint in cream and butter (1947) New Zealand Journal of Science and Technology, A28, pp. 305-307; Mishra, B., Priyadarsini, K.I., Sudheer Kumar, M., Unnikrishnan, M.K., Effect of O-glycosilation on the antioxidant activity and free radical reactions of a plant flavonoid, Chrysoeriol (2003) Bioorganic Medicinal Chemistry, 11, pp. 2677-2685; Misra, H.P., Fridovich, I., The role of superoxide anion in the autoxidation of epinephrine and a simple assay for superoxide dismutase (1972) Journal of Biological Chemistry, 247, pp. 3170-3175; Monig, H., Messerschmidt, O., Streffer, C., Chemical radio-protection in mammals and in man (1990) Radiation Exposure and Occupational Risks, pp. 97-143. , Scherer E, Streffer C, Trott K-R, editors. Berlin: Springer-Verlag; Moran, A., DePierre, J.W., Mannervick, B., Levels of glutathione, glutathione reductase, glutathione-S-transferase activities in rat liver (1979) Biochimica Biophysica Acta, 582, pp. 67-68; Nomura, T., Yamaoka, K., Sakai, K., Elevation of antioxidants in the kidneys of mice by low-dose irradiation and its effect on Fe3+-NTA-induced kidney damage (2002) International Congress Series, 1236, pp. 481-485; Onyilagha, J., Bala, A., Hallett, R., Gruber, M., Soroka, J., Westcott, N., Leaf flavonoids of the cruciferous species, Camelina sativa, Crambe spp., Thlaspi arvense and several other genera of the family Brassicaceae (2003) Biochemical Systematics and Ecology, 31, pp. 1309-1322; Parasassi, T., Giusti, A.M., Gratton, E., Monaco, E., Raimondi, M., Ravagnan, G., Sapora, O., Evidence for an increase in water concentration in bilayers after oxidative damage of phospholipids induced by ionizing radiation (1994) International Journal of Radiation Biology, 65, pp. 329-334; Paris, F., Fuks, Z., Kang, A., Capodieci, P., Juan, G., Ehleiter, D., Haimovitz-Friedman, A., Kolesnick, R., Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice (2001) Science, 293, pp. 293-297; Prabhakar, K.R., Srinivasan, K.K., Padma, G.M.R., Chemical investigation, anti-inflammatory and wound healing properties of Coronopus didymus (2002) Pharmaceutical Biology, 40, pp. 490-493; Prabhakar, K.R., Veeresh, V.P., Vipan Kumar, P., Sudheer Kumar, M., Priyadarshini, K.I., Rao, B.S.S., Unnikrishnan, M.K., Bioactivity guided fractionation of Coronopus didymus Linn: A Free radical scavenging perspective Phytomedicine, , (In press) doi: 10.1016/j.phymed.2005.07.003; Priyadarshini, K.I., Naik, D.B., Moorthy, P.N., Mittal, J.P., (1995) Proceedings of the 7th Tihany Symposium on Radiation Chemistry, p. 105. , Bhabha Atomic Research Center, Trombay, Mumbai, India; Raskin Ribnicky, D.M., Komarnytsky, S., Ilic, N., Poulev, A., Borisjuk, N., Brinker, A., Moreno, D.A., Fridlender, B., Plants and human health in the twenty-first century (2002) TRENDS in Biotechnology, 20, pp. 522-532; Robert, J.W., Spencer, J.P.E., Rice-Evans, C., Serial review: Flavonoids and isoflavones (phytoestrogens): Absorption, metabolism, and bioactivity (2004) Free Radical Biology and Medicine, 36, pp. 838-849; Sedlak, J., Lindsay, R., Estimation of total, protein-bound, and nonprotein sulfhydryl groups in tissue with Ellman's reagent (1968) Analytical Biochemistry, 25, pp. 192-205; Springfield, E.P., Eagles, P.K.F., Scott, G., Quality assessment of South African herbal medicines by means of HPLC finger-printing (2005) Journal of Ethnopharmacology, 101, pp. 75-83; Tannehill, S.P., Mehta, M.P., Amifostine and radiation therapy: Past, present, and future (1996) Seminars in Oncology, 23 (SUPPL. 8), pp. 69-77; Uma Devi, P., Normal tissue protection in cancer therapy: Progress and prospects (1998) Acta Oncologica, 37, pp. 247-252; Uma Devi, P., Ganasoundari, A., Rao, B.S.S., Srinivasan, K.K., In vivo radioprotection by ocimum flavanoids: Survival of mice (1999) Radiation Research, 151, pp. 74-78; Verhoeven, D.T., Goldbohm, R.A., Van Poppel, G., Epidemiological studies on Brassica vegetables and cancer risk (1996) Cancer Epidemiology Biomarkers & Prevention, 5, pp. 733-748; Weiss, J.F., Landauer, M.R., Protection against ionizing radiation by antioxidant nutrients and phytochemicals (2003) Toxicology, 189, pp. 1-20; Weiss, J.F., Pharmacological approaches to protection against radiation-induced lethality and other damage (1997) Environmental Health Perspective, 105 (SUPPL. 6), pp. 1473-1478; Willson, R.L., Free radical repair mechanisms and the interaction of glutathione, Vit C and Vit E (1983) Radioprotectors and Anticarcinogens, pp. 1-22. , Nygaard OF, Simic MG, editors. New York: Academic Press

PY - 2006

Y1 - 2006

N2 - Purpose: To evaluate and optimize the radioprotective ability of the most potent fraction of an aqueous extract of Coronopus didymus in whole body γ-irradiated Swiss albino mice and to evaluate the antioxidant status and lipid peroxidation of the livers of the surviving mice. To correlate the free radical scavenging studies with in vivo radioprotection ability. Materials and methods: Swiss albino mice were treated with either vehicle or the different doses of extract/fraction suspension by an i.p. route, 30 min before exposure to 10 Gy γ-irradiation and the animals were monitored twice daily for any signs of radiation toxicity and mortality. Radiation dose response (7-11 Gy), optimization of route, time of drug administration and evaluation of dose response factor (DRF) at the best dose of the fraction was studied. Endogenous antioxidant status and lipid peroxidation of the livers of the mice surviving on the 31st day was evaluated by using spectrophotometric methods. Results: The most active free radical scavenging fraction (CDF1) as assessed by competition kinetic studies using pulse radiolysis showed maximum in vivo radioprotection of 70% at a dose of 400 mg/kg body weight (bw) compared to corresponding 10 Gy irradiated control. Optimum radioprotection was observed upon i.p. administration, 30 min prior to 10 Gy irradiation and DRF at a dose of 400 mg/kg bw for 30 day survival was found to be 1.07. The levels of endogenous antioxidant enzymes and lipid peroxidation in the CDF1 treated surviving mice were found to reverse back to their normal levels. Conclusions: The optimum dose, time and route of drug administration for maximum radioprotection by CDF1 were determined. The reversal of the levels of endogenous antioxidant enzymes and lipid peroxidation indicates reduced oxidative stress in CDF1 treated surviving mice. © 2006 Informa UK Ltd.

AB - Purpose: To evaluate and optimize the radioprotective ability of the most potent fraction of an aqueous extract of Coronopus didymus in whole body γ-irradiated Swiss albino mice and to evaluate the antioxidant status and lipid peroxidation of the livers of the surviving mice. To correlate the free radical scavenging studies with in vivo radioprotection ability. Materials and methods: Swiss albino mice were treated with either vehicle or the different doses of extract/fraction suspension by an i.p. route, 30 min before exposure to 10 Gy γ-irradiation and the animals were monitored twice daily for any signs of radiation toxicity and mortality. Radiation dose response (7-11 Gy), optimization of route, time of drug administration and evaluation of dose response factor (DRF) at the best dose of the fraction was studied. Endogenous antioxidant status and lipid peroxidation of the livers of the mice surviving on the 31st day was evaluated by using spectrophotometric methods. Results: The most active free radical scavenging fraction (CDF1) as assessed by competition kinetic studies using pulse radiolysis showed maximum in vivo radioprotection of 70% at a dose of 400 mg/kg body weight (bw) compared to corresponding 10 Gy irradiated control. Optimum radioprotection was observed upon i.p. administration, 30 min prior to 10 Gy irradiation and DRF at a dose of 400 mg/kg bw for 30 day survival was found to be 1.07. The levels of endogenous antioxidant enzymes and lipid peroxidation in the CDF1 treated surviving mice were found to reverse back to their normal levels. Conclusions: The optimum dose, time and route of drug administration for maximum radioprotection by CDF1 were determined. The reversal of the levels of endogenous antioxidant enzymes and lipid peroxidation indicates reduced oxidative stress in CDF1 treated surviving mice. © 2006 Informa UK Ltd.

U2 - 10.1080/09553000600876686

DO - 10.1080/09553000600876686

M3 - Article

VL - 82

SP - 525

EP - 536

JO - International Journal of Radiation Biology

JF - International Journal of Radiation Biology

SN - 0955-3002

IS - 8

ER -