SSaudi Journal of Biological Sciences 15 (1) 25-33 June 2008
ISSN 1319-562 X
The Official Journal of the Saudi Biological Society
htt:www.saudibiosoc.com

Biochemical and Molecular Evaluation of Genetic Effects of Rhazya stricta (Decne) Leafs Extract on Aspergillus terreus

N. A. Baeshin, S. H. Qari*, J. S. M. Sabir and A. M. ALhejin**
Department of Biological Science, Faculty of Science, King Abdulaziz University, P.O. Box 9028,
Jeddah - 21413, Saudi Arabia
*Department of Biology , Teachers College, Umm Al-Qura university. P.O. Box 2203,
Makkah, Saudi Arabia (E-Mail: sqarinet@gmail.com)
**Medical Biology Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia

Abstract

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Dense conidial suspensions of Aspergillus terreus were treated with elevated concentrations of aqueous extracts of the wild plant Rhazya stricta leaves. Samples were taken at regular intervals in each treatment and assayed for survival percentage, auxotrophic mutants, quantities of DNA and total protein and farther subjected to RAPD and SDS-PAGE tests, respectively. It was found that the extract has potent lethal and mutagenic activities. Survival percentage decreased as the concentration or time of exposure increased. Frequency of auxotrophic mutants increased with increase in concentration or exposure time. Most auxotrophic mutants were amino acid requiring mutants. Quantity of DNA of each mutant was significantly less than in corresponding control and so on for total protein. The RAPD results demonstrated polymorphic numbers of genetic bands, which were the electrophoretic products of PCR for all mutants compared with the wild type strain. SDS-PAGE results expressed a polymorphism of protein bands as well. All these results strongly point out the mutagenicity of the leaves extract of R. stricta.

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