In vivo Comparative Studies on Antigenotoxicity of Date Palm (Phoenix Dactylifera L.) Pits Extract Against DNA Damage Induced by N-Nitroso-N-methylurea in Mice.

Aqueous extract of the date palm (Phoenix dactylifera L.) pits was prepared and its antigenotoxic activity was evaluated against N-Nitroso-N-methylurea (NMU) induced mutagenic effect in mice, using chromosome aberration (CA), micronuclei (MN) and DNA fragmentation assays as experimental end points in male mice. Date pits extract (DPE) was given orally to mice at the dose 25 mg/25 g mouse for successive five days in a week up to four consecutive weeks. NMU was used as mutagen and was given intraperitoneal (i.p) injection at single dose 80 mg/kg b.w., 24 hr after last dose of DPE in pre-treatment regimen and 24 hr before the first dose of DPE in the post-treatment regimen. Mice were scarified after one, two and seven days after the end of treatment. The results have shown that pre-and post-treatment regimens of DPE were significantly restored the DNA damage induced by NMU, as revealed by lowering of the occurrence of CAs and MN in bone marrow cells and inhibition of hepatic DNA fragmentation. These findings suggested that DPE produced their inhibitory activity either by desmutagenic or bioantimutagenic manner in pre-and post-treatment regimens respectively.

Cytogenetic effects of rifampicin in somatic and germinal cells of the mouse.

The genotoxicity of rifampicin was tested for sister chromatic exchange in bone marrow cells and for structural chromosomal aberrations in mouse germ cells. Sister chromatid exchange frequency increased after 160, 240 and 310 mg kg-1 body wt. doses but not after 80 mg kg-1. In spermatocytes, 80 mg kg-1 rifampicin increased the frequency of chromosomal aberrations from the 3.5% control level to 14% after 1 day and 34.5% after 7 days.

Cytogenetic effects of pesticides. III. Induction of micronuclei in mouse bone marrow by the insecticides cypermethrin and rotenone.

The production of micronuclei in mouse bone marrow by the pyrethroid insecticide, cypermethrin and the botanical insecticide, rotenone was examined. Three routes of administration were used for the insecticides: intraperitoneal, oral and dermal. The different routes of treatment with cypermethrin and rotenone caused toxicity of marrow as indicated by a significant increase in the percentage of polychromatic erythrocytes (PEs) over that of the control. Cypermethrin showed mutagenic potential as evidenced by a positive response in the micronucleus assay. Oral administration of the insecticide at a dietary level of 900 ppm for 7 and 14 consecutive days as well as double and multiple (total 4) dermal treatments (360 mg/kg body wt.) induced a statistically significant increase in the frequency of PEs with micronuclei. The conducted intraperitoneal (i.p.) treatments with cypermethrin: single injection at 60 and 180 mg/kg body wt., double and multiple injections (total 3) at 60 mg/kg body wt. did not affect the percentage of PEs with micronuclei. The different treatments with rotenone: single, double and multiple (i.p.) injections (total 3) at 2 and 3 mg/kg body wt., oral administration for 14 consecutive days at dietary level of 225 ppm and multiple dermal treatments (total 4) with 135 mg/kg body wt. showed no effect on the frequency of micronuclei in PEs.