Radioprotective and antiproliferative activity of Viscum album in lymphocytes exposed to gamma radiation

In the present study, the effect of Viscum album methanolic (VaM) extract and Methanol: Hexane (VaMH) fraction against gamma radiation induced radioprotection and mitogen proliferation in mice splenic lymphocytes was examined. Both VaM and VaMH inhibited the in vitro lymphocyte proliferation induced by concavalin A (Con A) in a dose dependent manner at higher dose of 100 μg and at lower doses 10 μg, also exhibited effective cell growth inhibition by inducing cancer cells to undergo G2/M phase arrest and apoptosis. Whereas the generation of ROS acts as a mediator in Both VaM and VaMH induced cell growth inhibition. On the contrary, it significantly inhibited the radiation-induced DNA damage in splenocytes as indicated by decrease in DNA fragmentation. In-vitro radioprotective activity was studied in plasmid pBR322 DNA and their effect on gamma radiation induced DNA damage. Estimation of apoptosis, Cell viability by Trypan blue, Mitogen induced proliferation, measurement of ROS, DNA Laddering and pBR322 DNA damage study was also carried out. Most important finding of the present study was VaM and VaMH contains naturally occurring flavonoids and phenolic compound, effectively protected cells against radiation and prolonged the survival of mice exposed to a lethal dose of γ-radiation and it also showed strong anti-proliferative affect. Several natural products have been shown to protect cells against radiation damage by virtue of their antioxidant properties. (author)