Evaluation of Cytogenetic Effects of Isoproturon on the Root Meristem Cells of Allium sativum

Objective\ To validate the use of Allium sativum as a reliable test model for genotoxicity, isoproturon, a substituted phenylalkylurea herbicide, was evaluated on the root meristem cells by this plant system. Method\ Test concentrations were selected by determining EC50 and root tips were exposed to various concentrations for 6 or 24 hr. EC50 concentration was calculated to be 70.8 ppm for the root growth. In addition to root growth retardation exposure to isoproturon induced morpholoogical changes like discolouration and stiffness of roots. Results\ Exposure to various experimental concentrations of isoproturon (35-280 ppm), including EC50, significantly and dose-dependently inhibited the mitotic index and induced chromosome breaks/mitotic aberrations at 6 or 24 hr. Conclusion\ The frequency of aberrations was found to be decreased in a dose dependant manner at 24 or 48 hr post exposure, however in comparison of control cells the frequency of aberrations was considerably high which indicates genotoxicity potentials of isoproturon. Further, present study also suggests that Allium sativum is a sensitive, efficient, and reliable test system for measuring the genotoxicity potential of environmental chemicals.

Induction of Chromosomal Aberrations by Propoxur in Mouse Bone Marrow Cells

Propoxur is a widely used dithiocarbamate insecticide. In this study, the clastogenic effect of propoxur has been evaluated using chromosomal aberration assay in mouse bone marrow cells. Single i. p. administration of propoxur, at 25 mg/kg b.wt., a maximum tolerated dose (MTD) and 12 .5mg/kg b.wt (50% of MTD) have significantly induced different types of aberrations after 24 h of treatment. The aberrations were dose and time dependent and reached a maximum after 24 h of exposure. The sresult suggest a genotoxic potential of propoxur.

Differential Genotoxicity of the Crude Leaf Extract of a Medicinal Plant, Casearia tomentosa

The genotoxic potentiality of the crude leaf extract of Casearia tomentosa, a medicinal preparation, has been evaluated in Swiss albino mice. The extract significantly induced the division_disruptive chromosomal changes in bone marrow cells as well as in primary spermatocytes; the latter also exhibited marked increase in synaptic disruptions. A significant decrease in sperm count was noted. The incidence of structural damages in chromosomes, however, remained within the range of control level frequency. This herbal preparation, therefore, appears to be primarily spindle_poisoning in its action, but not clastogenic. The probable mechanism of this differential genotoxicity is discussed.

Assessment of phytotoxic, genotoxic and enzyme inhibition potential of Sterculia diversifolia

OBJECTIVE:To evaluate Sterculia diversifolia stem bark and leaves for phytotoxic,genotoxic and enzymes inhibition potential.METHODS:Phytotoxic activity of both stem bark and leaves were screened using Lemna minor.The genotoxic activity of Sterculia diversifolia stem bark and leaves extracts were tested using comet assay protocol while enzyme inhibition activity of crude extract and various fractions of both stem bark and leaves were evaluated using acetyl cholinesterase,lipoxygenase,β-glucuronidase,urease,xanthine oxidase and carbonic anhydrase.RESULTS:Phytotoxic activity showed significant results in dose dependant manner in both stem bark(ethyl acetate and n-butanol)and leaves(ethyl acetate,nbutanol and n-hexane)fractions.In genotoxic activity,dichloromethane fraction showed significant activity followed by ethyl acetate fraction.Acetyl cholinesterease inhibitory activity showed significant results in both stem bark and leaves fractions,while significant lipoxygenase inhibition was shown by ethyl acetate,dichloromethane,crude extract and n-hexane fractions of both stem bark and leaves.β-glucuronidase,urease and carbonic anhydrase inhibitory activity showed highly significant results in ethyl acetate fraction of both stem bark and leaves,while xanthine oxidase inhibition was shown by dichloromethane fraction of stem bark and leaves extracts.CONCLUSIONS:This study emphasizes the important phytotoxic,genotoxic and enzyme inhibition effects of Sterculia diversifolia stem bark and leaves.Hence,it is clear that Sterculia diversifolia stem bark and leaves possess phytotoxic,genotoxic and enzyme inhibitory agents.