الكشف عن السمية الخلوية و الجزيئية للمستخلص الخام لهلام الصبار aloe vera L. في جذور نبات البصل allium cepa

الملخص EN

The cellular and molecular toxicity effect of Aloe Vera crude extract on meristem cells of onion (Allium cepa) roots were studied .

Different concentrations of this crude extract (%2 , %5 ,%10, %20and 40%) were used at different periods ; 24 ,48 and 72 hour .

Number of chromosomal aberrations and the mitotic index was calculated .

In addition, the genetic effects were observed by using randomly amplified polymorphic DNA ( RAPD ) technique .

The results showed that the gel crud extract of Aloe vera had inhibition effects on the growth of the onion roots with 10% EC50 value.

Significant effects of this gel crud extract were also observed on the chromosomal aberration and mitotic index by decreasing of divided cell rates.

The toxic effect of 20% concentration of gel crud extract was decreased the mitotic index under 50% , in the comparison with control sample .

Chromosomal aberration were also observed in divided cells of onion roots, which exposed to different concentrations at different periods .

The higher frequent type of this chromosomal aberrations , which observed are stickiness , disturbed , bridge , c-mitosis , vagrant and star telophase .

The result of RAPD technique reveled differences in number of DNA bands and their molecular weights of the treated samples , which exposed to high concentration of crud extract in comparison with the control sample .

The result of the genetic stability ratio (% GTS), also showed that Aloe vera crud extract have genetic toxicity at 40% concentration.