Mutagenicity In Ames Test Research Articles

Toxicological profiling of methanolic seed extract of Abutilon indicum (L.) Sweet: in-vitro and in-vivo analysis

Ethnopharmacological relevanceAbutilon indicum, a shrub of the Malvaceae family, is found abundantly in tropical countries like India. A. indicum is widely used for its high medicinal properties. Traditionally, A. indicum seed powder is consumed to treat piles, constipation, chronic cystitis, gonorrhea, gleet, and pregnancy-related problems. Despite having numerous medicinal properties and widespread traditional use of A. indicum seeds, scientific validation, and toxicity studies have yet to be documented. Aims of the studyThe primary objective of this study is to conduct a comprehensive study on phytochemical profiling, in-vitro cytotoxicity, mutagenicity, and in-vivo acute and sub-acute toxicity, and genotoxicity on animal models of methanolic extract of A. indicum seed (MAS). Materials and methodsThe qualitative analysis of MAS was explored through FTIR and HR LC-MS. For in-vitro cytotoxicity, the HEK-293 cell line was used, and the TA100 (Staphylococcus typhimurium) bacterial strain was used for the Ames mutagenicity test. A single oral dose of 250, 500, 1000, or 2000 mg/kg body weight of MAS was given to each male and female rat for acute toxicity study and observed for 14 days for any toxicity signs. In the sub-acute toxicity study, 250, 500, or 1000 mg/kg body weight of MAS was administered orally to each rat for 28 days. The experimental animals were weighed weekly, and general behavior was monitored regularly. After 28 days of the experiment, the rats were sacrificed, and different serum biochemical, hematological, and histological analyses were performed. The blood samples of different doses of MAS were used for genotoxicity study through comet assay. ResultsFTIR analysis found different functional groups, which indicated the presence of phenolics, flavonoids, and alkaloids. HR LC-MS analysis depicts several components with different biological functions. The cell cytotoxicity and Ames mutagenicity results showed minimal toxicity and mutagenicity up to a certain dose. The acute toxicity study conducted in Wistar albino rats demonstrated zero mortality among the animals, and the LD50 value for seed extract was determined to be 2000 mg/kg body weight. Sub-acute toxicity assessments indicated that the administration of seed extract resulted in no adverse effects at dosages of 250 and 500 mg/kg body weight. However, at higher doses, specifically 1000 mg/kg body weight, the liver of the experimental rats exhibited some toxic effects. In the genotoxicity study, minimal DNA damage was found in 250 and 500 mg/kg doses, respectively, but slightly greater DNA damage was found in 1000 mg/kg doses in both male and female rats. ConclusionsThe consumption of A. indicum seed powder is deemed safe; however, doses exceeding 500 mg/kg body weight may raise concerns regarding use. These findings pave the path for the creation of innovative medicines with improved efficacy and safety profiles.

Phenolic compounds occurrence and human health risk assessment in potable and treated waters in Western Cape, South Africa.

Phenolic pollutants from industrial and agricultural activities pose a major threat to the world's potable water supply. The persistent micro-pollutants often find their way into drinking water sources with possible adverse human health implications. In this study, bottled water, tap water, and wastewater treatment plant (WWTP) effluent samples from the Boland region of the Western Cape, South Africa were assessed to determine 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) levels using HPLC/DAD instrumentation. The selected area is known for its vast agricultural ventures and wineries. Evaluation of the human health risk (cancer risk) for the pollutants was conducted using the hazard quotient (HQ). The Ames mutagenicity test was also conducted using the Salmonella typhimurium T98 and T100 strains and the S9 activation enzyme. Trace levels of the phenolics were detected in the samples with a range of 9.32 × 10-7-1.15 × 10-4mg/L obtained for 4-CP, and 8.80 × 10-7-1.72 × 10-4mg/L recorded for 2,4-DCP. Both compounds had levels below the limit of 0.01mg/L prescribed by South African legislation. The assessed HQ for the phenolic concentrations indicates a low level of potential ecological risk and none of the samples had a cancer risk value that exceeded the regulatory limit. The possibility of the analyzed samples causing cancer is unlikely, but non-carcinogenic adverse effects were found. Strong mutagenicity was observed for the T98 strains with a potential ability to cause mutation toward the insertion or deletion of a nucleotide. The T100 bacterial strain showed very slight mutagenicity potential, however, it is unlikely to cause any mutation. The levels of phenolics in the potable water samples may pose a significant threat to human health. Hence, screening persistent organic chemicals in potable water sources and evaluating their potential human health effects is pertinent to prevent associated health challenges.

Pyrazolo[5,1‐b]quinazolines and Their Bis‐analogues Linked to Different Spacers: Regioselective Synthesis, Antibacterial Screening and SwissADME Prediction Study

AbstractThe regioselective synthesis of a new series of pyrazolo[5,1‐b]quinazolines was carried out using a three‐component protocol. The protocol involved the reaction of the appropriate benzaldehydes, dimedone, and 1H‐pyrazole‐ 3,5‐diamine in DMF at 150 °C. Using a similar protocol, three additional series of bis(pyrazolo[5,1‐b]quinazolines), linked to different spacers, were prepared utilizing the respective bis(aldehydes). The new products showed a wide spectrum of antibacterial activity against six different the American Type Culture Collection (ATCC) bacterial strains. In general, p‐xylene‐linked bis(pyrazolo[5,1‐b]quinazolines) had good antibacterial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values up to 8.3 and 16.6 μM, respectively. Additionally, (4‐nitrophenyl)‐linked pyrazolo[5,1‐b]quinazoline had the best antibacterial activity with MIC/MBC values up to 2.1/4.3 μM. The Salmonella typhimurium reverse mutation assay (Ames mutagenicity test) was used to conclude that the (4‐nitrophenyl)‐linked product was not mutagenic to the Salmonella strains. Both the drug‐likeness model score and the SwissADME predict the (4‐nitrophenyl)‐linked product‘s good physicochemical properties, and drug likeness.

Synthesis, Antimicrobial and Mutagenic Activity of a New Class of d-Xylopyranosides.

Eight N-[2-(2',3',4'-tri-O-acetyl-α/β-d-xylopyranosyloxy)ethyl]ammonium bromides, a new class of d-xylopyranosides containing a quaternary ammonium aglycone, were obtained. Their complete structure was confirmed using NMR spectroscopy (1H, 13C, COSY and HSQC) and high-resolution mass spectrometry (HRMS). An antimicrobial activity against fungi (Candida albicans, Candida glabrata) and bacteria (Staphylococcus aureus, Escherichia coli) and a mutagenic Ames test with Salmonella typhimurium TA 98 strain were performed for the obtained compounds. The greatest activity against the tested microorganisms was shown by glycosides with the longest (octyl) hydrocarbon chain in ammonium salt. None of the tested compounds exhibited mutagenic activity in the Ames test.

Degradation of Aflatoxin B1 in Moldy Maize by Pseudomonas aeruginosa and Safety Evaluation of the Degradation Products

Aflatoxin B1 (AFB1) is the most harmful mycotoxin commonly found in food and feed. Pollution from AFB1 causes serious economic and health issues worldwide because it causes strong mutagenicity and carcinogenicity in humans and animals. In this study, Pseudomonas aeruginosa was used to degrade AFB1 in moldy maize, and the safety of this biological method was investigated using genotoxicity and cytotoxicity tests. Using response surface methodology, we established the optimal conditions for degrading AFB1 by the fermentation supernatant of P. aeruginosa. Under these conditions, the degradation rate of AFB1 reached 99.67%. Furthermore, the Ames mutagenicity test showed that AFB1 treated with P. aeruginosa fermentation supernatant for 72 h was not mutagenic. CCK-8 cell assay showed that AFB1 cytotoxicity was significantly reduced after degradation. Overall, our findings show that the fermentation supernatant of P. aeruginosa may be a good candidate for biodegradation of AFB1.

Multiple endpoint in vitro toxicity assessment of a prototype heated tobacco product indicates substantially reduced effects compared to those of combustible cigarette

This study aimed to compare the aerosol chemistry and in vitro toxicological profiles of two prototype Heated Tobacco Product (p-HTP) variants to the 1R6F Reference Cigarette. In the neutral red uptake screen the p-HTPs were 37–39-fold less potent than 1R6F, in the micronucleus assay, responses to the p-HTPs were 8–22-fold less, and in the Ames test mutagenicity was weak or removed compared to 1R6F. The cardiovascular scratch wound assay revealed 58-fold greater wound healing impairment following exposure to 1R6F smoke extracts than the p-HTPs. Furthermore, in seven cell stress-related high content screening endpoints (cell count, cytochrome c release, mitochondrial membrane potential, GSH depletion, NFkB translocation, phosphorylation of c-jun and phosphorylation of H2AX), at 4 and 24 h, responses were substantially greater to 1R6F smoke extracts at comparable nicotine levels. The reduced in vitro effects of the p-HTPs were attributed to substantial reductions (90–97%) in selected HPHCs measured compared to in 1R6F smoke. The multiple endpoint in vitro assessment approach provides greater mechanistic insight and the first reported toxicological characterisation of these p-HTPs in the literature. Overall, the findings contribute to the growing weight of evidence that HTPs may offer a reduced harm mode of nicotine delivery to adult smokers.

Microwave-assisted synthesis of nicotinonitrile and/or arene-linked bis(chromene-thiazoles) as new VRE and MRSA inhibitors

Two series of nicotinonitrile and/or arene-linked bis(thiazoles) possessing chromene units are efficiently prepared in this study. A one-pot protocol was designed to prepare the target hybrids involved in the reaction of the respective salicylaldehydes, 2-cyanoethanethioamide, and the appropriate bis(α-haloketone). The reaction was irradiated by microwaves at 100 °C for 40–90 min in dioxane and mediated by piperazine to produce the desired products in 84–95% yields. Nicotinonitrile-linked hybrids 2b, and 2c attached to 6-(4-chlorophenyl) or 6-(4-nitrophenyl) units, respectively, had the best antibacterial activity, particularly against Staphylococcus aureus, and Enterococcus faecalis strains. They showed equipotent efficacy to ciprofloxacin with MIC/MBC values in the ranges from 5.9 to 12.0 µM. Additionally, 2c demonstrated comparable inhibitory activity to linezolid against MRSA and VRE strains with MIC/MBC values ranging from 2.9 to 11.8 µM. The Ames mutagenicity test was used to conclude that 2c was not mutagenic to the Salmonella strains.

Cancer and chemicals: A research-inspired laboratory exercise based on the Ames test for mutagenicity.

Laboratory courses should cultivate enthusiasm for research and an appreciation for real-world scientific challenges to retain undergraduate students and encourage them to pursue STEM-related careers. Course-based undergraduate research experiences (CURE) have emerged as an inclusive pedagogical model that facilitates laboratory skill development, while also improving self-efficacy and critical thinking skills. Herein, an innovative research-inspired Ames test for mutagenicity project is described. Students choose their own project theme and investigate substances using both TA98 and TA100 strains of Salmonella typhimurium to evaluate the potential for frameshift mutations and base-pair substitutions, respectively. An appropriate test concentration of each substance is first determined via a cytotoxicity assay, providing an additional learning opportunity. Students also study the mutagenicity of test substance metabolites using commercially available rat liver extracts to simulate metabolism. Overall, these experiences provide a comprehensive research project with high relevancy to human health and real-world importance. This laboratory module was assessed using CURE pre- and post-course surveys to evaluate learning gains and benefits. Assessment data illustrated that students appreciated the discovery aspect of the research project and gained skills related to reading scientific literature and effective poster presentations. Student-reported benefits of research project participation included learning new laboratory techniques, enhanced scientific writing skills, an increased tolerance for and understanding of common research challenges, and the confidence to tackle more complex research endeavors. Narrative feedback from students was very positive, with project highlights being the opportunity to select their own test substances and create new knowledge, as well as the analysis of results.

Multitask Deep Neural Networks for Ames Mutagenicity Prediction.

The Ames mutagenicity test constitutes the most frequently used assay to estimate the mutagenic potential of drug candidates. While this test employs experimental results using various strains of Salmonella typhimurium, the vast majority of the published in silico models for predicting mutagenicity do not take into account the test results of the individual experiments conducted for each strain. Instead, such QSAR models are generally trained employing overall labels (i.e., mutagenic and nonmutagenic). Recently, neural-based models combined with multitask learning strategies have yielded interesting results in different domains, given their capabilities to model multitarget functions. In this scenario, we propose a novel neural-based QSAR model to predict mutagenicity that leverages experimental results from different strains involved in the Ames test by means of a multitask learning approach. To the best of our knowledge, the modeling strategy hereby proposed has not been applied to model Ames mutagenicity previously. The results yielded by our model surpass those obtained by single-task modeling strategies, such as models that predict the overall Ames label or ensemble models built from individual strains. For reproducibility and accessibility purposes, all source code and datasets used in our experiments are publicly available.

P12-48 Streamlining the Ames mutagenicity test by online monitoring of the oxygen transfer rate in 96-well microplate scale

P12-48 Streamlining the Ames mutagenicity test by online monitoring of the oxygen transfer rate in 96-well microplate scale

Ficus septica exudate, a traditional medicine used in Papua New Guinea for treating infected cutaneous ulcers: in vitro evaluation and clinical efficacy assessment by cluster randomised trial

Infected cutaneous ulcers are major health problems for children living in rural areas of Papua New Guinea. The inaccessibility of affected populations and lack of access to basic healthcare, make a local plant-based therapy an attractive treatment option. We assessed Ficus septica exudate in biological assays relevant to wound healing. We then carried out a clinical trial to determine the exudate's efficacy in healing small cutaneous ulcers compared with Savlon antiseptic cream, and soap and water washing. Pre-clinical in vitro assessment of the exudate was carried out using assays to monitor the pro-inflammatory responses of M1 macrophages and neutrophils, antibacterial assays using known ulcer pathogens, an Ames test for mutagenicity and LC-MS chemical analysis of the exudate. An open label cluster-randomised clinical trial was performed, enrolling participants from three different clusters with skin lesions less than 1 cm in diameter. Each cluster comprising 50 participants was randomly assigned to one of three treatment arms namely topical exudate, topical Savlon antiseptic cream, and standard care (soap and water treatment), all administered daily for 2 days. The primary outcome was clinical healing/improvement measured at days 7 and 14, assessed by three dermatologists using blinded photographs. The primary analysis was assessed as non-inferiority of F. septica treatment based on the risk difference for healing/improvement. In vitro, the exudate which is rich in the alkaloid ficuseptine, was found to be non-mutagenic whilst also inhibiting pro-inflammatory responses and exhibiting antibacterial activity. When administered to participants enrolled in the clinical trial, no significant differences were observed between the healing efficacy of F. septica exudate and the two comparator treatments (Savlon antiseptic cream and soap/water treatment). At day 14, but not at day 7, the efficacy of F. septica exudate for healing/improving the ulcers was non-inferior to Savlon antiseptic cream or water/soap treatment. F. septica exudate is non-mutagenic and has both bactericidal and anti-inflammatory properties. When applied topically to small cutaneous ulcers, the exudate has a healing effect that is non-inferior to Savlon antiseptic cream and standard treatment with soap and water at day 14. Our findings, which should be confirmed in larger clinical trials, have important public health implications.

Machine learning – Predicting Ames mutagenicity of small molecules

In modern drug discovery, detection of a compound's potential mutagenicity is crucial. However, the traditional method of mutagenicity detection using the Ames test is costly and time consuming as the compounds need to be synthesised and then tested and the results are not always accurate and reproducible. Therefore, it would be advantageous to develop robust in silico models which can accurately predict the mutagenicity of a compound prior to synthesis to overcome the inadequacies of the Ames test. After curation of a previously defined compound mutagenicity library, over 5000 molecules had their chemical fingerprints and molecular properties calculated. Using 8 classification modelling algorithms, including support vector machine (SVM), random forest (RF) and extreme gradient boosting (XGB), a total of 112 predictive models have been constructed. Their performance has been assessed using 10-fold cross validation and a hold-out test set and some of the top performing models have been assessed using the y-randomisation approach. As a result, we have found SVM and XGB models to have good performance during the 10-fold cross validation (AUROC >0.90, sensitivity >0.85, specificity >0.75, balanced accuracy >0.80, Kappa >0.65) and on the test set (AUROC >0.65, sensitivity >0.65, specificity >0.60, balanced accuracy >0.65, Kappa >0.30). We have also identified molecular properties that are the most influential for mutagenicity prediction when combined with chemical molecular fingerprints. Using the Class A mutagenic compounds from the Ames/QSAR International Challenge Project, we were able to verify our models perform better, predicting more mutagens correctly then the StarDrop Ames mutagenicity prediction and TEST mutagenicity prediction.

Chemical and in vitro bioanalytical assessment of drinking water quality in Manhiça, Mozambique

The chemical quality of drinking water is widely unknown in low-income countries. We conducted an exploratory study in Manhiça district (Mozambique) to evaluate drinking water quality using chemical analyses and cell-based assays. We measured nitrate, fluoride, metals, pesticides, disinfection by-products, and industrial organochlorinated chemicals, and conducted the bioassays Ames test for mutagenicity, micronuclei assay (MN-FACS), ER-CALUX, and antiAR-CALUX in 20 water samples from protected and unprotected sources. Nitrate was present in all samples (median 7.5 mg/L). Manganese, cobalt, chromium, aluminium, and barium were present in 90-100% of the samples, with median values of 32, 0.6, 2.0, 61, 250 μg/l, respectively. Manganese was above 50 μg/l (EU guideline) in eight samples. Arsenic, lead, nickel, iron, and selenium median values were below the quantification limit. Antimony, cadmium, copper, mercury, zinc and silver were not present. Trihalomethanes, haloacetic acids, haloacetonitriles and haloketones were present in 5-28% samples at levels ≤4.6 μg/l. DDT, dieldrin, diuron, and pirimiphos-methyl were quantified in 2, 3, 3, and 1 sample, respectively (range 12-60 ng/L). Fluoride was present in one sample (0.11 mg/l). Trichloroethene and tetrachloroethene were not present. Samples were negative in the in vitro assays. Results suggest low exposure to chemicals, mutagenicity, genotoxicity and endocrine disruption through drinking water in Manhiça population. High concentration of manganese in some samples warrants confirmatory studies, given the potential link to impaired neurodevelopment.

Pharmacognostic Characteristics and Mutagenic Studies of Alstonia boonei De Wild

Background and objectives: The bark of Alstonia boonei, known as stool wood, is sold in large quantities on the Ghanaian market. It is used for the treatment of numerous ailments including snake bites, worm infestation, malaria and rheumatic pains. For safety reasons, it is necessary to control the raw materials by setting simple but relevant parameters to ensure identity, purity and quality which have been the aim of the present study to authenticate the plant materials. Methods: The macroscopic, microscopic, physico-chemical, phytochemical, UV-visible, fluorescence, HPLC and elemental characteristics were evaluated. Mutagenicity was also investigated with the Ames test. Results: The leaf characteristics can be employed to preliminary confirm the identity of the plant.The greyish-green outer bark and inner cream bark is rough, short and splintery with a bitter taste.The powdered stem bark showed microscopic prismatic calcium oxalate crystals, scalariform xylem vessels and lignified brachysclereids. Phytochemicals present were alkaloids, saponins, tannins, flavonoids, glycosides and terpenes. The bark fluoresced reddish-brown in 50 %v/v H2SO4 under UV light of λ 254 nm and contained traces of Cd, Fe, Zn and As, which were within recommended limits. HPLC fingerprint showed peaks at 254 nm, and UV analysis in various solvents showed spectral shifts on ionization. A. boonei demonstrated mutagenicity in Ames test. Conclusion: The characteristic macroscopic, microscopic, physico-chemical and chemical parameters evaluated for the plant sample can be used in rapid identification, authentication and establishment of the quality of raw materials. This will improve the quality and hence efficacy. The mutagenicity suggests the need for further safety evaluation.

Reactivity prediction in aza-Michael additions without transition state calculations: the Ames test for mutagenicity

Animal testing remains a contentious ethical issue in predictive toxicology. Thus, a fast, versatile, low-cost quantum chemical model is presented for predicting the risk of Ames mutagenicity in a series of 1,4 Michael acceptor type compounds. This framework eliminates the need for transition state calculations, and uses an intermediate structure to probe the reactivity of aza-Michael acceptors. This model can be used in a variety of settings e.g., the design of targeted covalent inhibitors and polyketide biosyntheses.

Statistical treatment of cytotoxicity in Ames bacterial reverse mutation assays can provide additional structure–activity relationship information

The bacterial reverse mutation assay, that is, the Ames test, measures mutations that reverse the inactivation of a gene involved in the synthesis of either histidine in Salmonella bacteria or tryptophan in Escherichia coli. The classic dose–response curve of an Ames assay plots number of reverse mutations (“revertants”) on the y-axis versus dose of the test chemical on the x-axis. Frequently, the dose–response curve resembles a parabola with a linear initial slope resulting from the accumulation of mutations, which transitions to a downward curvature resulting from cell killing (cytotoxicity) at increasingly higher doses of the test chemical. For regulatory purposes, a positive Ames test is usually considered as induction of twice the number of reverse mutations above background levels. For research purposes, the potency of the mutagenic response can be calculated from measuring the initial slope of the mutagenic response. This initial slope can be calculated in a manner that disentangles the downward pull on the initial slope value provided by the initiation of cytotoxicity. For a dose–response curve resembling a parabola, both the initial positive slope representing mutagenicity and the secondary negative slope representing cytotoxicity can be calculated from the same dose–response curve. The Ames test is the most commonly conducted genotoxicity assay. When a series of molecular congeners are assayed in the Ames test for mutagenicity, additional consideration of the cytotoxicity can provide important structure–activity relationship information.

New in silico models to predict in vitro micronucleus induction as marker of genotoxicity

The evaluation of genotoxicity is a fundamental part of the safety assessment of chemicals due to the relevance of the potential health effects of genotoxicants. Among the testing methods available, the in vitro micronucleus assay with mammalian cells is one of the most used and required by regulations targeting several industrial sectors such as the cosmetic industry and food-related sectors. As an alternative to the testing methods, in recent years, lots in silico methods were developed to predict the genotoxicity of chemicals, including models for the Ames mutagenicity test, the in vitro chromosomal aberrations and the in vivo micronucleus assay. We developed several in silico models for the prediction of genotoxicity as reflected by the in vitro micronucleus assay. The resulting models include both statistical and knowledge-based models. The most promising model is the one based on fragments extracted with the SARpy platform. More than 100 structural alerts were extracted, including also fragments associated with the non-genotoxic activity. The model is characterized by high accuracy and the lowest false negative rate, making this tool suitable for chemical screening according to the regulators' needs. The SARpy model will be implemented on the VEGA platform (https://www.vegahub.eu) and will be freely available.

Abstract 5091: Inhibition of mutagenicity of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine ( PhIP) by aqueous extract (crude) and organic extract (pulegone) of Calamintha nepeta.

Abstract Inhibition of mutagenicity of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) by aqueous extract (crude) and organic extract (pulegone) of Calamintha nepeta. Calamintha nepeta (CN) is an aromatic mint used as a traditional medicinal herb in Europe and the Mediterranean for its broad range of biological activities; these include anti-inflammatory, antioxidant, antimicrobial, anti-ulcer, insecticidal, and cancer-preventive properties. Previous studies have revealed the apoptotic and cancer-preventing attributes of its major organic fractions: pulegone (PUL, 2760 ppm), D-limonene (385 ppm), and menthone (590 ppm). PUL (6.4 - 800 mg/plate) was not mutagenic in Salmonella typhimurium TA97, TA98, TA100, TA1535, or TA1537 regardless of S9 metabolic activation. When cooking at high temperatures, creatine, sugars, and amino acids begin to produce 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which yielded positive results in the Ames mutagenicity tests. PhIP is one of the most abundant heterocyclic amines (HCAs) in cooked meat and the U.S. Department of Health and Human Services’ National Toxicology Program has denounced it as "reasonably anticipated to be a human carcinogen". Thus, cancer of the prostate, breast, lung, esophagus, stomach, and colorectal may be related to high intake and high exposure to PhIP. This study assessed and compared the effects of total aqueous and organic extracts of CN on PhIP-induced mutagenesis using TA98 as the bacterial tester strain and rat liver 9000 x g supernatant (S9) as the metabolic activation system. Our results showed that both the crude aqueous extract and organic essential oil extract (PUL) of the herb significantly inhibited the mutagenicity of PhIP (both 0.1 and 1 µg/plate), bioactivated by S9 (800 mg/plate), in a dose-response fashion (p < 0.05). The percent inhibition of revertant formation for these two extracts against 0.1 µg/plate of PhIP were: 32%, 74%, 79%, 84%, and 90% regarding the total aqueous extract (0.1, 0.5, 1.0, 1.5, and 3 mg/plate) and 28%, 36%, 64%, 75%, and 97% for the PUL essential oil of the organic extract (1.0, 10, 50, 100, and 200 µg/plate). Both the aqueous and organic extracts revealed the same trend of significance (p < 0.05) concerning percent inhibition of revertant formation against PhIP (1 µg/plate) in a dose-response fashion. The organic fraction (PUL) maintained a stronger antimutagenic effect in comparison to the total aqueous effect. These results suggest that both aqueous crude extract and organic PUL extract of CN contain antimutagenic phytochemicals concerning PhIP-induced mutagenicity. Further study of their modulatory effects on metabolism and the DNA binding of PhIP is warranted to reveal the potential antimutagenicity mechanism and their chemopreventive properties against PhIP and potentially against other HCAs. Citation Format: Yanlingxue Wan, Ryan Hayes, Joshua Li, Kristin Ferrer, Padma T. Uppula, Brian Yuen Yau Wong. Inhibition of mutagenicity of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine ( PhIP) by aqueous extract (crude) and organic extract (pulegone) of Calamintha nepeta. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5091.

Assessment of Mutagenicity of Herbal Preparations from Al-Baha Region, Saudi Arabia

Background and Objective: Traditional use of herbal medicinal plants in Saudi Arabia is common and in particular in Al-Baha region either in rural or urban areas for treatment of several ailments and no reports have been found about the mutagenicity of Saudi medicinal plants. Here we investigated the mutagenic/genotoxic effects of four herbal plants methanolic extracts namely, Acalypha fruticosa, Aloe vera, Jatropha spp and Ricinus communis, using the Ames test Methodology: For assessment of the mutagenicity of these four plants, we used the bacterial reverse mutagenicity assay (Ames test) without any metabolic activation system. The plants methanolic extract concentrations used were 0.1, 1.0 and 5.0 mg/ml. Results: Low concentrations of the extracts (0.1 mg/ml) of the four plants were found to be non-mutagenic (p < 0.05), while only the extracts of Aloe vera and Jatropha were found to be mutagenic in the second concentration (1.0 mg/ml). Meanwhile, Acalypha fruticosa extract at 1.0 mg/ml was found to be non-mutagenic and Ricinu communis was found to be cytotoxic at this concentration. At the concentration of 5.0 mg/ml the three extracts (Acalypha fruticosa, Aloe vera, Jatropha ) were mutagenic. Conclusion: Only higher concentrations, 1.0 and 5.0 mg/ml extracts of the herbal plants Acalypha fruticosa, Aloe vera and Jatropha, were found to be mutagenic/genotoxic in the reverse bacterial mutagenicity Ames test.

Interactions of newly synthesized platinum nanoparticles with ICR-191 and their potential application

One of the greatest challenges of modern medicine is to find cheaper and easier ways to produce transporters for biologically active substances, which will provide selective and efficient drug delivery to the target cells, while causing low toxicity towards healthy cells. Currently, metal-based nanoparticles are considered a successful and viable solution to this problem. In this work, we propose the use of novel synthesis method of platinum nanoparticles (PtNPs) connected with their precise biophysical characterization and assessment of their potential toxicity. To work as an efficient nanodelivery platform, nanoparticles should interact with the desired active compounds spontaneously and non-covalently. We investigated possible direct interactions of PtNPs with ICR-191, a model acridine mutagen with well-established biophysical properties and mutagenic activity, by Dynamic Light Scattering, fluorescence spectroscopy, and Isothermal Titration Calorimetry. Moreover, to determine the biological activity of ICR-191-PtNPs aggregates, we employed Ames mutagenicity test, eukaryotic cell line analysis and toxicity test against the model organism Caenorhabditis elegans. PtNPs’ interesting physicochemical properties associated to the lack of toxicity in a tested range of concentrations, as well as their ability to modulate ICR-191 biological activity, suggest that these particles successfully work as potential delivery platforms for different biologically active substances.