In Vitro Genotoxicity Assessment from the Glycyrrhiza New Variety Extract

The various species that comprise the genus Glycyrrhiza (Licorice) have long been used as oriental herbal medicines in Asian countries. Wongam (WG), which is a new variety of Glycyrrhiza, was developed in Korea to overcome the limitations of low productivity, environmental restrictions, and an insufficient presence of glycyrrhizic acid and liquiritigenin. In this study, we evaluated WG extract’s genotoxicity through an in vitro bacterial reverse mutation (AMES) test, an in vitro chromosome aberration test, and an in vivo mouse bone marrow micronucleus test. In the AMES test, WG extract at concentrations of up to 5000 µg/plate showed no genotoxicity regardless of S9 mix. No chromosome aberrations appeared after 6 h in 1400 µg/mL WG extract regardless of S9 mix or in 1100 µg/mL WG extract after 24 h without S9 mix. Nor was there a significant increase in the number of micronucleated polychromatic erythrocytes to total erythrocytes up to 5000 mg/kg/day for 2 days detected in the micronucleus test. These results confirm that WG extract is safe for use as an herbal medicine, as it precipitates no detectable genotoxic effects.

Three regulatory compliant test systems show no signs of MDMA-related genotoxicity

3,4 Methylenedioxymethamphetamine (MDMA)-assisted therapy has been recently found to be highly effective for treatment of posttraumatic stress disorder (PTSD). Previous studies have been inconclusive in elucidating potential MDMA genotoxicity. We performed three regulatory compliant studies to investigate the potential of genotoxic effects of MDMA treatment in humans: (1) an in vitro bacterial reverse mutation (Ames) assay, (2) an in vitro chromosome aberration test in Chinese hamster ovary cells, and (3) an in vivo micronucleus study in male Sprague Dawley rats. MDMA was found to not have genotoxic effects in any of the assays at or above clinically relevant concentrations.

Evidence of cytogenetic and histological damage in specimens of Astyanax lacustris (Pisces, Characidae) exposed to the hydrogen cyanide-based herbicide Dormex®

The herbicide Dormex®, a solution of hydrogen cyanamide, is a growth regulator capable of breaking the dormancy of fruit plants, and is commonly applied in agriculture. However, the biological effects of this product on non-target organisms are unknown. The present study investigated the biological response of Astyanax lacustris (Lütken, 1875) specimens exposed to Dormex® using a chromosome aberration test, the mitotic index, and the histological analysis of the gills. Forty specimens of Astyanax lacustris were obtained from a local breeding facility and divided into 10 groups (nine experimental and one control) with four fish in each aquarium (group). The control group was maintained for 24 hours in dechlorinated water while the experimental groups were allocated to one of nine different treatments, with three concentrations of Dormex®, 0.05, 0.1 and 0.5 mL L-1, and exposure for 24, 48 and 72 hours. The fish exposed to Dormex® presented chromosomal aberrations of a number of types, including chromosomal breaks, acentric fragments, decondensation, and gaps at the three Dormex® concentrations, at all exposure times. The mitotic index decreased significantly in comparison with the control group. The histological preparations of the gills revealed alterations such as hyperplasia, and lamellar fusion and edema, whereas in the control group the structure of the gills was preserved. The cytogenetic analysis revealed the genotoxic potential of the herbicide Dormex® and the morphological alterations of the gills demonstrated the sensitivity of the fish, which responded rapidly to the stressor. These findings reinforce the need for special care and restrictions on the use of these herbicides in agricultural areas located near aquatic environments.

Effects of hypersensitivity and induced radioresistance in CHO-K1 cells following exposure to gamma-rays and accelerated carbon ions

The study presents results of investigations on chromosome aberrations (CA) yield in Chinese ham-ster ovary cells after exposure to gamma-rays and accelerated carbon ions (455 MeV/amu) at doses less than 1 Gy in the pristine Bragg curve plateau and behind the Bragg peak, where normal tissues are situated in the course of radiotherapy. Initial parts of dose curves for total CA and terminal deletions frequencies differed from linear-quadratic dependence and the region of induced radioresistance were observed at 0.1-0.6 Gy for gamma-rays. The similar curve shapes were detected for carbon ions, but plateau region was shorter (0.15-0.35 Gy). Despite the uniform shape of the dose curves for the CA yield, a definite dependence of the cytogenetic effect on the linear energy transfer (LET) is observed. The CA frequency increased with LET rising in the order: gamma-irradiation (0.2 keV/μm), carbon ions at the Bragg curve plateau (10-12 keV/μm) and at the «tail» of Bragg peak (25-27 keV/μm). Outside this range, the yield of chromosome aberrations also enhanced with increasing LET in the same order. The results obtained confirm that the hypersensitivity and induced radioresistance phenomena are characteristic for low level exposure to low-LET and middle-LET radiations when chromosome aberration test is used.

Assessment of Potential Clastogenic Effect of the Insecticide Mospilan® 20SP in Human Peripheral Blood Lymphocytes After in Vitro Exposure

Acetamiprid, that is known as the commercial formulation Mospilan® 20SP is the part of the neonicotinoid insecticide group and is widely used against various pests. In our study we assessed the potential clastogenic effects of Mospilan® in human peripheral blood lymphocytes in vitro using a chromosome aberration test. The lymphocytes were treated with acetamiprid in the concentration range of 5, 10, 25 and 50 µg.ml−1 for 24 and 48 h. After 24 h exposure, the insecticide induced statistically significant higher levels of chromosome aberrations from the concentration of 10 µg.ml−1 (P < 0.05 and P < 0.001) and a significant decrease in mitotic index (MI) at the concentrations of 25 and 50 µg.ml−1 (P < 0.05 and P < 0.01), respectively. After a 48 h exposure, we found a dose dependent increase in the percentage of chromosome aberrations at all concentrations (P < 0.05; P < 0.01 and P < 0.001) and a decrease in MI at concentrations of 25 and 50 µg.ml−1 (P < 0.05 and P < 0.01). Our results indicated that neonicotinoid insecticide formulations containing acetamiprid may have potential cytotoxic and genotoxic effects.

Genotoxicity Evaluation of an Ethanol Extract Mixture of Astragali Radix and Salviae miltiorrhizae Radix

Myelophil, a combination of Astragali Radix and Salviae Radix, is one of the most commonly used remedies for disorders of Qi and blood in traditional Chinese medicine. Based on the clinical applications of these plants, in particular to pregnant woman, this study aimed to evaluate the genotoxic potential of an ethanol extract mixture of the above two herbs, called Myelophil. Following the Organization for Economic Cooperation and Development (OECD) Guideline methods, a genotoxicity test was conducted using a bacterial reverse mutation test with Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and Escherichia coli (WP2μvrA), an in vitro mammalian chromosome aberration test using a Chinese hamster ovary cell line (CHO-K1), and an in vivo mammalian erythrocyte micronucleus test using ICR mouse bone marrow. In the Ames test, for both types of mutations (base substitution and frameshift) under conditions with/without an S9 mix up to 5,000 μg/plate, Myelophil did not increase the number of revertant colonies of all S. typhimurium strains as well as E. coli strain. For both short (6 h) and long tests with/without S9 mix, the chromosome aberration test did not show any significant increase in the number of structural or numerical chromosome aberrations by Myelophil. In addition, no significant change in the number of micronucleated polychromatic erythrocytes or polychromatic erythrocytes was observed in the bone marrow of an ICR mouse administered Myelophil orally at 2,000 mg/kg/day for 2 days, respectively. These results are the first to provide experimental evidence that Myelophil, an ethanol extract mixture of Astragali Radix and Salviae Radix, has no risk of genotoxicity.