mutagenic effect of khat and the protective effect of vitamin C.

Khat [Catha edulis Forsk], is the a flowering evergreen tree or large shrub, which grows in the Horn of Africa and southwestern Arabia. Vitamin C. is one of the available, famous and cheapest antioxidants. The present experimental animal study is designed to observe the mutagenic changes due to chewing fresh khat, and the possible protective effect of vitamin C. Thirty mice were used in this study, they were divided into three groups; the first one [10 mice] was given khat extract intra gastric as a single daily dose for thirty days, the second group [10 mice] was given khat extract and vitamin C. by the same route dose, and period, the third group was considered as a control group, it was given distilled water by the same route and period. The animals were sacrificed after the designated period, the bone marrow were extracted from the femora, and prepared for microscopic examination [chromosomal study and micronuclei level]. generally there is slight decrease of the body weight, the chromosomal study revealed decrease of the mitotic index, deletion type of structural aberration, and increase in the micronuclei level. The protective effect of vitamin C. is evident by the increase of the mitotic index, decrease percentage of the detected aberration and micronuclei level

Cytogenetic and histological study of lead on albino rat testes

Lead is the oldest environmental contaminant, and the 5th most utilized metal in the U.S. which is a known abortifacient and spermicidal agent in case of high exposure. The present experimental animal study is designed to observe the changes in the testes, and the chromosomal aberrations in the bone marrow cells due to excessive use of lead. Distilled water and lead acetate were administered intraperitonially to control and experimental groups respectively, as a single daily dose for a thirty days treatment period. Animals were sacrificed after the designated period, their testes were weighed and cut into small pieces. The testicular pieces were prepared for histological study, embedded in paraffin and then 5 mm thick sections were made, stained with PAS-sulfurous acid, haematoxylin and Eosin and Iron haematoxylin and examined microscopically for qualitative assessment of germinal epithelium. The bon marrow of both fernora were prepared for chromosomal study, stained with Giemsa stain. In the rats of group B mean, weight and average tissue ratio of the paired testes was 1.145 gm and 0.0036 re spectively. which is significantly less than control., thickening of basement membrane and an early arrest of spermatogenesis, scanty Leydig cells, prominent Sertoli cells and collapsed blood vessels, with generalized atrophy of the testes. The chromosomal study reveled two types of structural aberration break and aneuploidy, in addition to increase of the mitotic index for group B in relation to the control group. In lead toxicity, chromosomal aberrations, and testicular atrophy are detected, also degeneration of spermatogenic and Leydig cells, are detected