Studies on radio protective and ameliorative effects of bioactive compounds from Alstonia scholaris using cultured human lymphocytes

Abstract

It is well established that ionizing radiation causes damage to DNA. Exposure newlineof individuals to ionizing radiation is quite frequent at certain work places (X-ray newlineoperators, Nuclear power plant workers); or to patients undergoing radio therapy, newlineor at times during accidental exposure. Therefore, for such individuals it is crucial to newlinedevelop or search compounds with potency to protect, modulate or mitigate the newlineharmful insults of ionizing radiation. newlineMost radio-protectants are toxic at higher doses or at recurrent usage and newlineare expensive as well. This has spurred interest in exploring natural products. Since newlineplants or plant products have innumerable pharmacological properties and are often newlinelesser toxic, less expensive and devoid of any known side effects, they have been the newlinetarget in pursuit of radio-protectants. newlineIn the present study, we first tried to compare possible ameliorative effects newlineof aqueous and methanolic extracts from bark, stem and leaves of Alstonia scholaris newlineagainst BLM-induced cytogenetic alterations in cultured human lymphocytes. The newlineresults indicated that the bark, but not stem or leaf possesses ameliorative effects. newlineBased on the results so obtained, we challenged the second objective by newlineinvestigating (qualitative as well as quantitative) phytochemicals present within the newlinebark, stem and leaves of A. scholaris. Total glycosides, alkaloids, gums and mucilage newlinewere present in higher quantities in the bark as compared to stem and leaf, newlineindicating their probable role in ameliorative effects. These results encouraged us to newlinestudy probable mechanisms involved in amelioration and link the same with radioprotective newlineproperty. The bark extracts exhibited total antioxidant and free radical newlinescavenging potentials, suggesting their probable role in radio-protection and radiomodulation. newlineFurther, results of chemosensitive G2 assay indicated that bark extracts newlinehave DNA repair capabilities against BLM-induced DNA damage. newline newline