Journal of Pharmacy And Bioallied Sciences
Journal of Pharmacy And Bioallied Sciences Login  | Users Online: 1979  Print this pageEmail this pageSmall font sizeDefault font sizeIncrease font size 
    Home | About us | Editorial board | Search | Ahead of print | Current Issue | Past Issues | Instructions | Online submission

Year : 2010  |  Volume : 2  |  Issue : 3  |  Page : 213-219

Himalayan Bioresource Rhodiola imbricata as a promising radioprotector for nuclear and radiological emergencies

1 Division of CBRN Defence, Institute of Nuclear Medicine and Allied Sciences, Brig SK Mazumdar Marg, Delhi - 110 054, India
2 Department of Plant Sciences, Campus Drive College of Agriculture and Bioresources, University of Saskatchewan Saskatoon, Saskatchewan S7N 5A8, Canada

Correspondence Address:
Rajesh Arora
Division of CBRN Defence, Institute of Nuclear Medicine and Allied Sciences, Brig SK Mazumdar Marg, Delhi - 110 054
Login to access the Email id

Source of Support: DRDO,, Conflict of Interest: None

DOI: 10.4103/0975-7406.68503

Rights and Permissions

In recent years, a lot of interest has been generated world over in the area of radioprotection for first responders going to work in the hot zones at the incident site. A large number of molecular drugs have been screened for radioprotective efficacy, but with little success. The requirement of differential radioprotection necessitates a holistic approach, which can be realized using herbs in view of their multifaceted mode of action. Our earlier studies showed the radioprotective potential of Rhodiola imbricata, a Himalayan high-altitude plant. In this study, our focus has been to compare the pro-oxidant/antioxidant activities of three fractionated extracts of R. imbricata. The aqueous fraction exhibited significant (P < 0.05) pro-oxidant activity (up to 100 mg/ml) under metal ion-induced stress ± flux [transition metal (Fe/Cu) ± 0.25 kGy]. A decrease in the dielectric constant of the solvent system utilized for extraction, exhibited a significant (P < 0.05) negative correlation (−0.955) with mean protection potential of lipid against radiation flux. Such an effect was visualized as a significant shift from pro-oxidant to antioxidant activity in methanolic fraction (dielectric constant = 33), as compared to aqueous fraction (dielectric constant = 80). Aqueous fraction is predominantly pro-oxidant at maximal concentrations, indicating its anticancer potential. The presence of transition metals modulates such a biphasic activity differentially in various fractions, i.e., the conversion of Fe(III) or Cu(II) to Fe(II) or Cu(I), respectively, due to the presence of certain bioactive constituents (electron donation at lower concentrations), favors pro-oxidant activity. On the other hand, certain other active constituents involved in metal ion chelation contributed to the overall antioxidant activity. The methanolic fraction exhibited significant antioxidant activity up to 250 mg/ml, which contributed to its radioprotective efficacy. The aquo-methanolic fraction exhibited (disparate properties), i.e., concentration-dependant cytotoxicity (up to 250 mg/ml) and cytoprotection at 1000 mg/ml. R. imbricata, in general, exhibited a significant solvent-dependant variation in radioprotective efficacy. In conclusion, solvent extraction and dose are crucial in bioactivity modulation and R. imbricata could be developed as a potential prophylactic radiation countermeasure for use in nuclear and radiological emergencies.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded198    
    Comments [Add]    
    Cited by others 11    

Recommend this journal