Radioprotective effect of podophyllotoxin in Saccharomyces cerevisiae.
Recent reports showed that whole extract of Podophyllum hexandrum was radioprotective in mice. Podophyllotoxin is one of the major constituents of the whole extract of Podophyllum. In this study we report on the radioprotective action of podophyllotoxin in Saccharomyces cerevisiae yeast. Proliferating yeast cells pretreated with podophyllotoxin (2.5-5.0 microg/mL) for > or =3 hours showed a higher surviving fraction after (60)Co-gamma-irradiation (200-600 Gy) than did the irradiated cells not pretreated with podophyllotoxin. The maximum increase (2.0 times) in surviving fraction was observed in cells treated with 2.5 microg/mL podophyllotoxin, 5 hours before (60)Co-gamma-irradiation (400 Gy). Podophyllotoxin was not mutagenic or recombinogenic at radioprotective doses (2.5 microg/mL). A post-irradiation decrease in revertants and gene convertants was observed in cells treated with podophyllotoxin (2.5 microg/mL podophyllotoxin, -5 hours, 400 Gy). This study indicates that podophyllotoxin is radioprotective in yeast, and its radioprotective effects in higher eukaryotes would be worth investigating.
Bala
Madhu
M
Division of Radiation Biology, Institute of Nuclear Medicine and Allied Sciences, Delhi 110054, India. balainma44@hotmail.com
Goel
Harish Chandra
HC
D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D011034:Podophyllotoxin / Q000633:toxicity; D011035:Podophyllum; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*
D010936:Plant Extracts; D011837:Radiation-Protective Agents; D011034:Podophyllotoxin