ABSTRACT
Despite toxic effects of some essential oils, their use is not under control. With a view to increasing trend of utilisation of herbal products, some biological aspects of Thymus daenensis are repoted here for the first time. Antimicrobial properties using disk diffusion and dilution tests, nitric oxide radical scavenging by Marcocci et al method and cytotoxic properties employing dimethylthiazolyl diphenyltetrazolium bromide reduction test were carried out with Thymus daenensis and commercial Thyme essential oils and their main chemical compound, thymol. The microbial sensitivity to the oils were in Candida albicans>E. coli>S. aureus>P. aeruginosa order. The minimum inhibitory and microbicidal concentrations were in the range of 0.04-10mg/ml. Nitric oxide radical scavenging was dose dependent with an IC50 of 5, 75, 863 micro g, and total phenolics of 644.07 +/- 6.79, 16.94 +/- 2.55, 10.33 +/- 2.31 micro g Gallic acid equivalent per mg sample and total flavonoid content of 73.51 +/- 1.34, 0.56 +/- 0.02, 0.21 +/- 0.09 mg Catechin equivalent per gram T. daenensis oil, commercial thyme oil and thymol respectively. The concentrations from T. daenensis oil, commercial thyme oil and thymol required to exert 50% fatal effect [IC50] on healthy human normal lymphocytes and Hela cells were 1455, 12.10, 2867 and 4.95, 3.61, 1730 micro g respectively. T. daenensis with its good antimicrobial property can prevent formation of toxic reactive oxygen species and as a good antioxidant, it can directly scavenge NO and O2-. With a view to cancerous cells killing properties of the oils at their lowest concentrations without fatal effect on normal healthy cells, feasibility of their application in combating cancerous cells may be promising
ABSTRACT
In Iran, Organ phosphorus pesticides such as chloropyrifos and diazinon are widely used in agriculture. These compounds inhibit activity of cholinesterase in nearly irreversible manner resulting in malfunction of nerve impulse transmission. This result in humans can produce illness or even death. Therefore, the present study aims to isolate various bacterial strains in specified contaminated regions. We selected one of the isolates that contain the highest OP-hydrolyzing capability for using such strain, in decontaminating environmentally harmful OP residues. In this study, vast waters from chemical factories and contaminated agricultural soil samples were used for isolation of several bacterial strains that contain OPAA enzyme are capable of utilizing chloropyrifos and diazinon as a source of carbon and phosphorus by selective enrichment on mineral salt medium [MSM], which contains chloropyrifos or diazinon. One strain was selected for analysis of degradation ability with growth studies and HPLC technique and characterization by Bergey's manual. From vast water and soil, ten bacterial strains were isolated using chloropyrifos and diazinon as source of carbon and phosphorus. One of them named IHU strain4; grows most rapidly and luxuriously and displays the highest organophosphate-hydrolyzing capability. On the basis of morphological and biochemical characteristics, the bacterial isolate was identified as a member of the genus pseudomonas. From these findings, it can be concluded that the isolated bacterial strain is able to utilize Organ phosphorus pesticides as a source of carbon and phosphorus. Utilization of these compounds by soil microorganisms is a crucial phenomenon by which these compounds are removed from the environment, thus, preventing environmental pollution. Results from the present study suggest that the isolated bacterial strain may be used for remediation of pesticide-contamination