Aloe polysaccharides mediated radioprotective effect through the inhibition of apoptosis.
Polysaccharides from aloe are always considered an effective radioprotector on irradiation-induced skin damage. The aim of this study was to determine if aloe polysaccharides (AP) have radioprotective effects on normal human cells in vitro and mouse survival in vivo and to explore the mechanism. Pretreatment with 50 microg/ml AP could improve the surviving fraction at 2 Gy (SF2) of three normal cell lines 293, ECV304, and C. liver from 41.5%, 46.5%, and 40.9% to 49.4%, 72.1%, and 89.1%, respectively. AP could also reduce the apoptotic rate of C. liver cells from 9.5% and 43.0% to 2.2% and 10.9% 48 h and 72 h after 2 Gy irradiation, respectively. Western blot analysis showed that pretreatment with AP could block the upregulation of pro-apoptotic p53, Bax, and Bad and the downregulation of Bcl-2 by irradiation. AP could lower thymocyte apoptosis of mice in vivo after 6 Gy irradiation and abrogate the cell cycle perturbation. Fifty mg/kg of AP treatment for 30 min before 7.5 Gy irradiation provided the best radioprotective effect and improved the 30-day survival rate of mice to 86.0%, from 10.0%. AP exerted radioprotective effects in vitro and in vivo through an inhibition of apoptosis.
Wang
Zong-Wei
ZW
Department of Pharmacology, Guangzhou University of Traditional Chinese Medicine School of Pharmaceutical Science, Guangzhou, P. R. China.
Zhou
Jun-Min
JM
Huang
Zhao-Sheng
ZS
Yang
An-Ping
AP
Liu
Zong-Chao
ZC
Xia
Yun-Fei
YF
Zeng
Yi-Xin
YX
Zhu
Xiao-Feng
XF
D000504:Aloe / Q000737:chemistry*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D008099:Liver / Q000166:cytology / Q000502:physiology / Q000528:radiation effects; D051379:Mice; D008815:Mice, Inbred Strains; D011134:Polysaccharides / Q000494:pharmacology*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D013950:Thymus Gland / Q000166:cytology / Q000502:physiology / Q000528:radiation effects
D011134:Polysaccharides; D011837:Radiation-Protective Agents