Evaluation of the in vitro and in vivo genotoxicity of a Dioscorea Rhizome water extract.

Dioscorea Rhizome is commonly used in traditional herbal medicines for the treatment of diabetes, hyperthyroidism, liver damage, neuropathy, and asthma. Here, we investigated the genotoxicity potential of D. Rhizome water extract (DRWE) using three standard battery systems in accordance with the test guidelines of the Organisation for Economic Cooperation and Development and Ministry of Food and Drug Safety as well as the principles of Good Laboratory Practice. A bacterial reverse mutation test (Ames test) was performed using the direct plate incorporation method in the presence or absence of a metabolic activation system (S9 mixture). The tester strains used included four histidine auxotrophic strains of Salmonella typhimurium, TA100, TA1535, TA98, and TA1537, along with a tryptophan auxotrophic strain of Escherichia coli, WP2 uvrA. An in vitro chromosome aberration test was performed using CHL/IU cells originally derived from the lung of a female Chinese hamster in the presence or absence of the S9 mixture. An in vivo mouse bone marrow micronucleus test was performed using male ICR mice. The micronucleus was confirmed after observation of the micro-nucleated polychromatic. The Ames test showed that DRWE did not induce gene mutations at any dose level in any of the tested strains. Additionally, DRWE did not result in any chromosomal aberrations specified in the in vitro chromosomal aberration and in vivo micronucleus tests. These results showed that DRWE exhibited neither mutagenic nor clastogenic potential in either the in vitro or in vivo test systems.

Toxicological assessments of an ethanol extract complex of Descurainia sophia and Peucedanum praeruptorum: Subacute oral toxicity and genotoxicity studies.

An ethanol extract complex of Descurainia sophia seeds and Peucedanum praeruptorum roots, called BP10A, has antitumor potential against colorectal cancer. In the present study, we evaluated the 28-day oral toxicity and the genotoxicity of BP10A. The subacute toxicity test was done through oral administration to mice. ICR mice (n = 10) received daily oral BP10A doses of 0, 500, 1000 and 2000 mg/kg for 28 consecutive days. During administration, general clinical signs, food consumption, organ weights, and hematologic, biochemical and histopathological parameters in male and female mice were assessed. No significant adverse effects up to the highest dose (2000 mg/kg) were found. The genotoxicity was evaluated using a battery of tests, including an in vitro bacterial reverse mutation (Ames) test, an in vivo micronucleus test using bone marrow cells in ICR mice and a chromosomal aberration test using CHL/IU cells. BP10A did not show any genotoxic signs in the Ames (up to 5000 µg/plate), micronucleus (up to 5000 mg/kg) and the chromosomal aberration tests (550-1750 µg/mL). Therefore, BP10A was considered safe based on the subacute toxicity and genotoxicity results, indicating that it is a useful pharmaceutical material with no adverse toxicity.

Assessment of the 4-week repeated-dose oral toxicity and genotoxicity of GHX02.

Herbal medicines are widely utilized for disease prevention and health promotion. GHX02 consists of mixtures including Gwaruin (Trichosanthes kirilowii), Haengin (Prunus armeniaca), Hwangryeon (Coptis japonica) and Hwangkeum (Scutellaria baicalensis). It has been purported to have therapeutic effectiveness in cases of severe bronchitis. Non-clinical safety testing comprised a single-dose oral toxicity study and a 28-day repeated-dose oral toxicity study with a 14-day recovery period, and genotoxicity was assessed by a bacterial reverse mutation test, in vitro chromosomal aberration test, in vivo mouse bone marrow micronucleus test and single cell gel electrophoresis assay (comet assay). In the single-dose oral toxicity study, the approximate lethal dosage is estimated to be higher than 5000 mg/kg in rats. Thus, the dosage levels were set at 0, 1250, 2500 and 5000 mg/kg/day in the 28-day repeated-dose oral toxicity study, and 10 male rats and 10 female rats/dose were administered GHX02. No clinical signs of toxicological significance were recorded in any animal during the dosing and the observation period in the single-dose study. The no-observed-adverse-effect level of GHX02 was 5000 mg/kg/day when administered orally for 28 days to male and female Sprague-Dawley rats. Despite increases in the frequencies of cells with numerical chromosomal aberration in the in vitro test, the increases were not considered relevant to the in vivo genetic risk. Except for the increase of in vitro numerical chromosomal aberration, clear negative results were obtained from other genetic toxicity studies.

Case-control study of the risk factors for acquisition of Pseudomonas and Proteus species during tigecycline therapy.

Tigecycline is an important agent in clinical practice because of its broad-spectrum activity. However, it has no activity against Pseudomonas or Proteus species. We conducted a case-control study to analyze risk factors for the acquisition of Pseudomonas or Proteus spp. during tigecycline therapy. Placement of suction drainage at infected wound sites, ICU stay, and neurologic disease were identified as independent risk factors for the acquisition of Pseudomonas and Proteus spp.