Mutagenic and antimutagenic potentials of fruit juices of five medicinal plants in Allium cepa L.: Possible influence of DPPH free radical scavengers

Mutagenic and antimutagenic activities of freeze dried fruit juices (FDFJ) of Morinda elliptica Ridl. (Rubiaceae), Morinda citrifolia L. (Rubiaceae), Averrhoa bilimbi L. (Oxalidaceae), Phyllantus acidus (L.) Skeels (Phyllantaceae) and Myristica fragrans Houtt. (Myristicaceae) in Allium cepa L were evaluated. Testing the mutagenic activity, onions were suspended in solution of different concentrations of FDFJ alone in tap water for 48 h. Thereafter, root tips were prepared and observed for dividing cells and chromosomal aberrations using a light microscope. Antimutagenicity screening was similar to the mutagenic evaluation, except that the solution of FDFJ was combined with 0.1% cylophosphamide-CP. Free radicals (2,2-diphenyl-1-picrylhyrazyl) scavenging activity of the FDFJ was tested using butylated hydroxylanisole (BHA) and butylated hydroxytoluene (BHT) as the standards and their phenolic contents were evaluated by comparing with gallic acid equivalents (GAE). The free radicals scavenging power of M. fragrans at 1 mg/ml was almost similar to that of BHA and BHT and its phenolic content was 21 ± 6.0 mg GAE/g, the highest among the tested juices. A. cepa cell division was inhibited in a dose-dependent manner by the FDFJ of M. fragrans, while the induced chromosomal aberrations were non dose dependent. The cytotoxicity and chromosomal aberrations of CP were suppressed throughout the tested concentrations of M. fragrans, unlike the effects of other four juices. These results suggest that the observed activities of FDFJ of M. fragrans may be due to the quantity and quality of phenolic compounds with antioxidant activity, suggesting its use in preventing the DNAdamaging effects of mutagens.Key words: Allium cepa, antimutagenicity, antioxidants, cyclophosphamide, mutagenicity