Evaluation of the radioprotective effect of Ageratum conyzoides Linn. extract in mice exposed to different doses of gamma radiation

G.C. Jagetia, A. Shirwaikar, S.K. Rao, P.M. Bhilegaonkar

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

The effect of various doses (0, 25, 50, 75, 100, 125, 150, 300, 600 and 900 mg kg-1) of the alcoholic extract of the plant Ageratum conyzoides Linn. (ACE), on the alteration of radiation-induced mortality in mice exposed to 10 Gy of gamma radiation was studied. The acute toxicity studies showed that the drug was non-toxic up to a dose of 3000 mg kg-1, the highest dose that could be tested for acute toxicity. Administration of ACE resulted in a dose-dependent decline in radiation-induced mortality up to a dose of 75 mg kg-1, the dose at which the highest number of survivors (70.83%) was observed. Thereafter, the number of survivors declined with increasing doses of ACE and a nadir was reached at 900 mg kg-1 ACE. Since the number of survivors was highest for 75 mg kg-1 ACE, this was considered the optimum dose for radioprotection and used in further studies in which mice were treated with 75 mg kg-1 ACE before exposure to 6, 7, 8, 9, 10 and 11 Gy of gamma radiation. The treatment of mice with 75 mg kg-1 ACE reduced the severity of symptoms of radiation sickness and mortality at all exposure doses, and a significant increase in survival was observed compared with the non-treated irradiated group. The ACE treatment effectively protected mice against the gastrointestinal as well as bone marrow related death, as revealed by the increased number of survivors at all irradiation doses. The dose reduction factor was found to be 1.3. To understand the mechanism of action, various doses of ACE were evaluated for their in-vitro scavenging action on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a chemically stable free radical. ACE was found to scavenge DPPH radicals in a concentration-dependent manner, indicating that the radioprotection afforded by ACE may be in part due to the scavenging of reactive oxygen species induced by ionizing radiation.
Original languageEnglish
Pages (from-to)1151-1158
Number of pages8
JournalJournal of Pharmacy and Pharmacology
Volume55
Issue number8
DOIs
Publication statusPublished - 2003

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Ageratum
Gamma Rays
Survivors
Radiation Dosage
Mortality
Radiation
Radiation Injuries
Plant Extracts
Ionizing Radiation
Free Radicals
Reactive Oxygen Species
Bone Marrow
Survival
Therapeutics
Pharmaceutical Preparations

Cite this

@article{23a2f909363149ddb64bd34ab4db1e3d,
title = "Evaluation of the radioprotective effect of Ageratum conyzoides Linn. extract in mice exposed to different doses of gamma radiation",
abstract = "The effect of various doses (0, 25, 50, 75, 100, 125, 150, 300, 600 and 900 mg kg-1) of the alcoholic extract of the plant Ageratum conyzoides Linn. (ACE), on the alteration of radiation-induced mortality in mice exposed to 10 Gy of gamma radiation was studied. The acute toxicity studies showed that the drug was non-toxic up to a dose of 3000 mg kg-1, the highest dose that could be tested for acute toxicity. Administration of ACE resulted in a dose-dependent decline in radiation-induced mortality up to a dose of 75 mg kg-1, the dose at which the highest number of survivors (70.83{\%}) was observed. Thereafter, the number of survivors declined with increasing doses of ACE and a nadir was reached at 900 mg kg-1 ACE. Since the number of survivors was highest for 75 mg kg-1 ACE, this was considered the optimum dose for radioprotection and used in further studies in which mice were treated with 75 mg kg-1 ACE before exposure to 6, 7, 8, 9, 10 and 11 Gy of gamma radiation. The treatment of mice with 75 mg kg-1 ACE reduced the severity of symptoms of radiation sickness and mortality at all exposure doses, and a significant increase in survival was observed compared with the non-treated irradiated group. The ACE treatment effectively protected mice against the gastrointestinal as well as bone marrow related death, as revealed by the increased number of survivors at all irradiation doses. The dose reduction factor was found to be 1.3. To understand the mechanism of action, various doses of ACE were evaluated for their in-vitro scavenging action on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a chemically stable free radical. ACE was found to scavenge DPPH radicals in a concentration-dependent manner, indicating that the radioprotection afforded by ACE may be in part due to the scavenging of reactive oxygen species induced by ionizing radiation.",
author = "G.C. Jagetia and A. Shirwaikar and S.K. Rao and P.M. Bhilegaonkar",
note = "Cited By :31 Export Date: 10 November 2017 CODEN: JPPMA Correspondence Address: Jagetia, G.C.; Department of Radiobiology, Kasturba Medical College, Manipal 576 119, India; email: gc.jagetia@mc.manipal.edu Chemicals/CAS: 1,1 diphenyl 2 picrylhydrazyl, 1898-66-4; Plant Extracts; Radiation-Protective Agents References: Abramowitz, M., Stegun, I.A., (1972) Handbook of Mathematical Functions, , Dover Publications, Inc., New York; Alaoui-Youssefi, A., Lamproglou, I., Drieu, K., Emerit, I., Anticlastogenic effects of Ginkgo biloba extract (EGb 761) and some of its constituents in irradiated rats (1999) Mutat. Res., 445, pp. 99-104; Aruna, K., Shivaramakrishnan, V.M., Plant products as protective agents against cancer (1990) Ind. J. Exp. Biol., 28, pp. 1008-1011; Bond, V.P., Fliedner, T.M., Archambeau, J.O., (1965) Mammalian Radiation Lethality, , Academic Press, New York; Ekundayo, O., Sharma, S., Rao, E.V., Essential oil of Ageratum conyzoides (1988) Planta Med., 54, pp. 55-57; Ganasoundari, A., Uma Devi, P., Rao, M.N.A., Protection against radiation induced chromosome damage in mouse bone marrow by Ocimum sanctum (1997) Mutat. Res., 373, pp. 271-276; Ganasoundari, A., Zare, S.M., Uma Devi, P., Modification of bone marrow radiosensitivity by medicinal plants extracts (1997) Br. J. Radiol., 70, pp. 599-602; Ghosh, M.N., Toxicity studies (1984) Fundamentals of Experimental Pharmacology, pp. 153-158. , In: Ghosh, M. N. (ed.); Scientific Book Agency, Calcutta; Githens, T.S., (1948) Drug Plants of Africa. African Handbooks Series, 8. , University of Pennsylvania, Philadelphia; Gonzalez, A.G., Aguiar, Z.E., Grillo, T.A., Luis, J.G., Rivera, A., Calle, J., Methoxyflavones from Ageratum conyzoides (1991) Phytochemistry, 30, p. 1269; Hahn, S.M., Krishna, M.C., Samuni, A., Degraff, W., Cuscela, D.O., Johnstone, P., Mitchell, J.B., Potential use of nitroxides in radiation oncology (1994) Cancer Res., 54, pp. 2006s-2010s; Jagetia, G.C., Baliga, S.M., Influence of the leaf extract of Mentha arvensis Linn. (mint) on survival of mice exposed to different doses of gamma radiation (2002) Strahlenther. Onkol., 2, pp. 91-98; Jagetia, G.C., Ganapathi, N.G., Inhibition of clastogenic effect of Liv 52 in bone marrow of mice (1989) Mutat. Res., 224, pp. 507-510; Jagetia, G.C., Ganapathi, N.G., Effect of copper glycinate on the radiation induced micronuclei formation in mice bone marrow (1990) Radiat. Environ. Biophys., 29, pp. 115-118; Jagetia, G.C., Uma Devi, P., Singatgeri, M.K., Singh, N., Kohli, R., Radiation modifying effect of Ocimum sanctum mouse survival studies (1986) Proceedings of the 56th Annual Session of the National Academy of Science India, p. 40; Jagetia, G.C., Ganapathi, N.G., Unnikrishnan, M.K., Copper glycinate protects mice exposed to various doses of gamma radiation (1993) Strahlenther. Onkol., 5, pp. 323-328; Jagetia, G.C., Baliga, S.M., Malagi, K.J., Sethukumar Kamath, M., The evaluation of the radioprotective effect of triphala (an Ayurvedic rejuvenating drug) in the mice exposed to γ-radiation (2002) Phytomedicine, 9, pp. 99-108; Jagetia, G.C., Baliga, S.M., Aruna, R., Rajanikant, G.K., Jain, V., Effect of abana (a herbal preparation) on the radiation-induced mortality in mice (2003) J. Ethnopharmacol., 86, pp. 159-165; Katsuri, T.R., Manithomes, T.M., Essential oil of Ageratum conyzoides: Isolation and structure of two new constituents (1967) Tetrahedron Lett., 27, p. 2573; Kissman, G., Groth, D., (1993) Plantas Infestantes e Novicas, , Basf Brasileira, S{\~a}o Paulo; Kong, T., Ah-N, G., Yu, R., Chen, C., Mandlekar, S., Primiano, T., Signal transduction events elicited by natural products: Role of MAPK and caspase pathways in homeostatic response and induction of apoptosis (2000) Arch Pharm Res., 23, pp. 1-16; Mensor, L.L., Menezes, F.S., Leitao, G.G., Reis, A.S., Dos Santos, T.C., Coube, C.S., Leitao, S.G., Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method (2001) Phytother. Res., 15, pp. 127-130; Miller, L.C., Tainter, M.L., Estimation of the ED50 and its error by means of logarithmic-probit graph paper (1944) Proc. Soc. Exp. Biol. Med., 57, p. 261; Negrelle, R.R.B., Sbalchiero, D., Cervi, A.C., (1988) Esp{\'e}cies Vegetais Utilizadas na Terap{\^e}utica Popular no Munic{\'i}pio de Curitiba, Paran{\'a}, Brasil, , Universudade Federal do Paran{\'a}, Curitiba; Oliveira, F., Akisue, M.K., Garcia, L.O., Caracteriza{\cc}{\~a}o farmacogn{\'o}stica da droga e do extrato flu{\'i}do de mentrasto, Ageratum conyzoides L (1993) Lecta, 11, pp. 63-100; Pari, K., Rao, P.J., Subrahmanyam, B., Rasthogi, I.N., Devakumar, C., Benzofuran and other constituents of the essential oil of Ageratum conyzoides (1998) Phytochemistry, 49, p. 1385; Penna, A., (1921) Notas Sobre Plantas Brasileiras, , Arajo Penna Filhos, Rio de Janeiro; Prieur, D.J., Young, D.M., Davis, R.D., Cooney, D.A., Homan, E.R., Dixon, R.L., Guarino, A.M., Procedures for pre-clinical toxicological evaluation of cancer chemotherapeutic agents: Protocols of the laboratory toxicology (1973) Cancer Chemother. Rep., 4, pp. 1-28; Quijano, L., Calderson, J.S., Gomez, G.F., Soria, I.E., Rios, T., Highly oxygenated flavonoids from Ageratum corymbosum (1980) Phytochemistry, 19, p. 2439; Revesz, L., The role of endogenous thiols in intrinsic radioprotection (1985) Int. J. Radiat. Biol., 47, pp. 361-368; Saini, M.R., Kumar, S., Jagetia, G.C., Saini, N., Effect of Liv 52 against radiation sickness and mortality (1984) Indian Pract., 37, pp. 1133-1138; Saini, M.R., Kumar, S., Uma Devi, P., Saini, N., Late effects of whole-body irradiation on the peripheral blood of mice and its modification by Liv. 52 (1985) Radiobiol. Radiother., 26, pp. 487-493; Sreejayan, N., Rao, M.N.A., Free radical scavenging activity of curcuminoids (1996) Arzneimittelforschung, 46, pp. 169-171; Sweeny, T.R., (1979) A Survey of Compounds from the Antiradiation Drug Development Program of the US Army Medical Research and Development Command, , Government Printing Office, Washington DC; Thali, S., Thatte, U., Dahanukar, S., The potential of Boerrhavia diffusa in radiation induced haemopoietic injury (1998) Amala Res. Bull., 18, pp. 20-22; Thomson, J.F., (1962) Radiation Protection in Mammals, , Reinhold Publishing Corporation, New York; Uma Devi, P., Bisht, K.S., Vinita, M.A., A comparative study of radioprotection by Ocimum sanctum flavonoids and synthetic aminothiol protectors in mice (1998) Br. J. Radiol., 71, pp. 782-784; Uma Devi, P., Ganasoundari, A., Rao, B.S.S., Srinivasan, K.K., In vivo radioprotection by Ocimum flavonoids in the survival of mice (1999) Radiat. Res., 151, pp. 74-78; Vidya, N., Devraj, S.N., Antioxidant effect of eugenol in rat intestine (1999) Ind. J. Exp. Biol., 37, pp. 1192-1195; Vyas, A.V., Mulchandani, N.B., Polyoxygenated flavone from Ageratum conyzoides (1988) Phytochemistry, 25, p. 2625; Yamamoto, L.A., Soldera, J.C., Emim, J.A., Goldinho, R.O., Souccar, C., Lapa, A.J., Pharmacological screening of Ageratum conyzoides L. (Mentrasto) (1991) Mem. Inst. Oswaldo Cruz, 86, pp. 145-147; Zhang, J., Sigdestad, C.P., Gemmell, M.A., Grdina, D.J., Modification of radiation response in mice by fractionated extracts of Panaz ginseng (1987) Radiat. Res., 112, pp. 156-163",
year = "2003",
doi = "10.1211/0022357021576",
language = "English",
volume = "55",
pages = "1151--1158",
journal = "Journal of Pharmacy and Pharmacology",
issn = "0022-3573",
publisher = "Pharmaceutical Press",
number = "8",

}

Evaluation of the radioprotective effect of Ageratum conyzoides Linn. extract in mice exposed to different doses of gamma radiation. / Jagetia, G.C.; Shirwaikar, A.; Rao, S.K.; Bhilegaonkar, P.M.

In: Journal of Pharmacy and Pharmacology, Vol. 55, No. 8, 2003, p. 1151-1158.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Evaluation of the radioprotective effect of Ageratum conyzoides Linn. extract in mice exposed to different doses of gamma radiation

AU - Jagetia, G.C.

AU - Shirwaikar, A.

AU - Rao, S.K.

AU - Bhilegaonkar, P.M.

N1 - Cited By :31 Export Date: 10 November 2017 CODEN: JPPMA Correspondence Address: Jagetia, G.C.; Department of Radiobiology, Kasturba Medical College, Manipal 576 119, India; email: gc.jagetia@mc.manipal.edu Chemicals/CAS: 1,1 diphenyl 2 picrylhydrazyl, 1898-66-4; Plant Extracts; Radiation-Protective Agents References: Abramowitz, M., Stegun, I.A., (1972) Handbook of Mathematical Functions, , Dover Publications, Inc., New York; Alaoui-Youssefi, A., Lamproglou, I., Drieu, K., Emerit, I., Anticlastogenic effects of Ginkgo biloba extract (EGb 761) and some of its constituents in irradiated rats (1999) Mutat. Res., 445, pp. 99-104; Aruna, K., Shivaramakrishnan, V.M., Plant products as protective agents against cancer (1990) Ind. J. Exp. Biol., 28, pp. 1008-1011; Bond, V.P., Fliedner, T.M., Archambeau, J.O., (1965) Mammalian Radiation Lethality, , Academic Press, New York; Ekundayo, O., Sharma, S., Rao, E.V., Essential oil of Ageratum conyzoides (1988) Planta Med., 54, pp. 55-57; Ganasoundari, A., Uma Devi, P., Rao, M.N.A., Protection against radiation induced chromosome damage in mouse bone marrow by Ocimum sanctum (1997) Mutat. Res., 373, pp. 271-276; Ganasoundari, A., Zare, S.M., Uma Devi, P., Modification of bone marrow radiosensitivity by medicinal plants extracts (1997) Br. J. Radiol., 70, pp. 599-602; Ghosh, M.N., Toxicity studies (1984) Fundamentals of Experimental Pharmacology, pp. 153-158. , In: Ghosh, M. N. (ed.); Scientific Book Agency, Calcutta; Githens, T.S., (1948) Drug Plants of Africa. African Handbooks Series, 8. , University of Pennsylvania, Philadelphia; Gonzalez, A.G., Aguiar, Z.E., Grillo, T.A., Luis, J.G., Rivera, A., Calle, J., Methoxyflavones from Ageratum conyzoides (1991) Phytochemistry, 30, p. 1269; Hahn, S.M., Krishna, M.C., Samuni, A., Degraff, W., Cuscela, D.O., Johnstone, P., Mitchell, J.B., Potential use of nitroxides in radiation oncology (1994) Cancer Res., 54, pp. 2006s-2010s; Jagetia, G.C., Baliga, S.M., Influence of the leaf extract of Mentha arvensis Linn. (mint) on survival of mice exposed to different doses of gamma radiation (2002) Strahlenther. Onkol., 2, pp. 91-98; Jagetia, G.C., Ganapathi, N.G., Inhibition of clastogenic effect of Liv 52 in bone marrow of mice (1989) Mutat. Res., 224, pp. 507-510; Jagetia, G.C., Ganapathi, N.G., Effect of copper glycinate on the radiation induced micronuclei formation in mice bone marrow (1990) Radiat. Environ. Biophys., 29, pp. 115-118; Jagetia, G.C., Uma Devi, P., Singatgeri, M.K., Singh, N., Kohli, R., Radiation modifying effect of Ocimum sanctum mouse survival studies (1986) Proceedings of the 56th Annual Session of the National Academy of Science India, p. 40; Jagetia, G.C., Ganapathi, N.G., Unnikrishnan, M.K., Copper glycinate protects mice exposed to various doses of gamma radiation (1993) Strahlenther. Onkol., 5, pp. 323-328; Jagetia, G.C., Baliga, S.M., Malagi, K.J., Sethukumar Kamath, M., The evaluation of the radioprotective effect of triphala (an Ayurvedic rejuvenating drug) in the mice exposed to γ-radiation (2002) Phytomedicine, 9, pp. 99-108; Jagetia, G.C., Baliga, S.M., Aruna, R., Rajanikant, G.K., Jain, V., Effect of abana (a herbal preparation) on the radiation-induced mortality in mice (2003) J. Ethnopharmacol., 86, pp. 159-165; Katsuri, T.R., Manithomes, T.M., Essential oil of Ageratum conyzoides: Isolation and structure of two new constituents (1967) Tetrahedron Lett., 27, p. 2573; Kissman, G., Groth, D., (1993) Plantas Infestantes e Novicas, , Basf Brasileira, São Paulo; Kong, T., Ah-N, G., Yu, R., Chen, C., Mandlekar, S., Primiano, T., Signal transduction events elicited by natural products: Role of MAPK and caspase pathways in homeostatic response and induction of apoptosis (2000) Arch Pharm Res., 23, pp. 1-16; Mensor, L.L., Menezes, F.S., Leitao, G.G., Reis, A.S., Dos Santos, T.C., Coube, C.S., Leitao, S.G., Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method (2001) Phytother. Res., 15, pp. 127-130; Miller, L.C., Tainter, M.L., Estimation of the ED50 and its error by means of logarithmic-probit graph paper (1944) Proc. Soc. Exp. Biol. Med., 57, p. 261; Negrelle, R.R.B., Sbalchiero, D., Cervi, A.C., (1988) Espécies Vegetais Utilizadas na Terapêutica Popular no Município de Curitiba, Paraná, Brasil, , Universudade Federal do Paraná, Curitiba; Oliveira, F., Akisue, M.K., Garcia, L.O., Caracterização farmacognóstica da droga e do extrato fluído de mentrasto, Ageratum conyzoides L (1993) Lecta, 11, pp. 63-100; Pari, K., Rao, P.J., Subrahmanyam, B., Rasthogi, I.N., Devakumar, C., Benzofuran and other constituents of the essential oil of Ageratum conyzoides (1998) Phytochemistry, 49, p. 1385; Penna, A., (1921) Notas Sobre Plantas Brasileiras, , Arajo Penna Filhos, Rio de Janeiro; Prieur, D.J., Young, D.M., Davis, R.D., Cooney, D.A., Homan, E.R., Dixon, R.L., Guarino, A.M., Procedures for pre-clinical toxicological evaluation of cancer chemotherapeutic agents: Protocols of the laboratory toxicology (1973) Cancer Chemother. Rep., 4, pp. 1-28; Quijano, L., Calderson, J.S., Gomez, G.F., Soria, I.E., Rios, T., Highly oxygenated flavonoids from Ageratum corymbosum (1980) Phytochemistry, 19, p. 2439; Revesz, L., The role of endogenous thiols in intrinsic radioprotection (1985) Int. J. Radiat. Biol., 47, pp. 361-368; Saini, M.R., Kumar, S., Jagetia, G.C., Saini, N., Effect of Liv 52 against radiation sickness and mortality (1984) Indian Pract., 37, pp. 1133-1138; Saini, M.R., Kumar, S., Uma Devi, P., Saini, N., Late effects of whole-body irradiation on the peripheral blood of mice and its modification by Liv. 52 (1985) Radiobiol. Radiother., 26, pp. 487-493; Sreejayan, N., Rao, M.N.A., Free radical scavenging activity of curcuminoids (1996) Arzneimittelforschung, 46, pp. 169-171; Sweeny, T.R., (1979) A Survey of Compounds from the Antiradiation Drug Development Program of the US Army Medical Research and Development Command, , Government Printing Office, Washington DC; Thali, S., Thatte, U., Dahanukar, S., The potential of Boerrhavia diffusa in radiation induced haemopoietic injury (1998) Amala Res. Bull., 18, pp. 20-22; Thomson, J.F., (1962) Radiation Protection in Mammals, , Reinhold Publishing Corporation, New York; Uma Devi, P., Bisht, K.S., Vinita, M.A., A comparative study of radioprotection by Ocimum sanctum flavonoids and synthetic aminothiol protectors in mice (1998) Br. J. Radiol., 71, pp. 782-784; Uma Devi, P., Ganasoundari, A., Rao, B.S.S., Srinivasan, K.K., In vivo radioprotection by Ocimum flavonoids in the survival of mice (1999) Radiat. Res., 151, pp. 74-78; Vidya, N., Devraj, S.N., Antioxidant effect of eugenol in rat intestine (1999) Ind. J. Exp. Biol., 37, pp. 1192-1195; Vyas, A.V., Mulchandani, N.B., Polyoxygenated flavone from Ageratum conyzoides (1988) Phytochemistry, 25, p. 2625; Yamamoto, L.A., Soldera, J.C., Emim, J.A., Goldinho, R.O., Souccar, C., Lapa, A.J., Pharmacological screening of Ageratum conyzoides L. (Mentrasto) (1991) Mem. Inst. Oswaldo Cruz, 86, pp. 145-147; Zhang, J., Sigdestad, C.P., Gemmell, M.A., Grdina, D.J., Modification of radiation response in mice by fractionated extracts of Panaz ginseng (1987) Radiat. Res., 112, pp. 156-163

PY - 2003

Y1 - 2003

N2 - The effect of various doses (0, 25, 50, 75, 100, 125, 150, 300, 600 and 900 mg kg-1) of the alcoholic extract of the plant Ageratum conyzoides Linn. (ACE), on the alteration of radiation-induced mortality in mice exposed to 10 Gy of gamma radiation was studied. The acute toxicity studies showed that the drug was non-toxic up to a dose of 3000 mg kg-1, the highest dose that could be tested for acute toxicity. Administration of ACE resulted in a dose-dependent decline in radiation-induced mortality up to a dose of 75 mg kg-1, the dose at which the highest number of survivors (70.83%) was observed. Thereafter, the number of survivors declined with increasing doses of ACE and a nadir was reached at 900 mg kg-1 ACE. Since the number of survivors was highest for 75 mg kg-1 ACE, this was considered the optimum dose for radioprotection and used in further studies in which mice were treated with 75 mg kg-1 ACE before exposure to 6, 7, 8, 9, 10 and 11 Gy of gamma radiation. The treatment of mice with 75 mg kg-1 ACE reduced the severity of symptoms of radiation sickness and mortality at all exposure doses, and a significant increase in survival was observed compared with the non-treated irradiated group. The ACE treatment effectively protected mice against the gastrointestinal as well as bone marrow related death, as revealed by the increased number of survivors at all irradiation doses. The dose reduction factor was found to be 1.3. To understand the mechanism of action, various doses of ACE were evaluated for their in-vitro scavenging action on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a chemically stable free radical. ACE was found to scavenge DPPH radicals in a concentration-dependent manner, indicating that the radioprotection afforded by ACE may be in part due to the scavenging of reactive oxygen species induced by ionizing radiation.

AB - The effect of various doses (0, 25, 50, 75, 100, 125, 150, 300, 600 and 900 mg kg-1) of the alcoholic extract of the plant Ageratum conyzoides Linn. (ACE), on the alteration of radiation-induced mortality in mice exposed to 10 Gy of gamma radiation was studied. The acute toxicity studies showed that the drug was non-toxic up to a dose of 3000 mg kg-1, the highest dose that could be tested for acute toxicity. Administration of ACE resulted in a dose-dependent decline in radiation-induced mortality up to a dose of 75 mg kg-1, the dose at which the highest number of survivors (70.83%) was observed. Thereafter, the number of survivors declined with increasing doses of ACE and a nadir was reached at 900 mg kg-1 ACE. Since the number of survivors was highest for 75 mg kg-1 ACE, this was considered the optimum dose for radioprotection and used in further studies in which mice were treated with 75 mg kg-1 ACE before exposure to 6, 7, 8, 9, 10 and 11 Gy of gamma radiation. The treatment of mice with 75 mg kg-1 ACE reduced the severity of symptoms of radiation sickness and mortality at all exposure doses, and a significant increase in survival was observed compared with the non-treated irradiated group. The ACE treatment effectively protected mice against the gastrointestinal as well as bone marrow related death, as revealed by the increased number of survivors at all irradiation doses. The dose reduction factor was found to be 1.3. To understand the mechanism of action, various doses of ACE were evaluated for their in-vitro scavenging action on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a chemically stable free radical. ACE was found to scavenge DPPH radicals in a concentration-dependent manner, indicating that the radioprotection afforded by ACE may be in part due to the scavenging of reactive oxygen species induced by ionizing radiation.

U2 - 10.1211/0022357021576

DO - 10.1211/0022357021576

M3 - Article

VL - 55

SP - 1151

EP - 1158

JO - Journal of Pharmacy and Pharmacology

JF - Journal of Pharmacy and Pharmacology

SN - 0022-3573

IS - 8

ER -