Toxicological Screening of Four Bioactive Citroflavonoids: In Vitro, In Vivo, and In Silico Approaches

Many studies describe different pharmacological effects of flavonoids on experimental animals and humans. Nevertheless, few ones are confirming the safety of these compounds for therapeutic purposes. This study aimed to investigate the preclinical safety of naringenin, naringin, hesperidin, and quercetin by in vivo, in vitro, and in silico approaches. For this, an MTT-based cytotoxicity assay in VERO and MDCK cell lines was performed. In addition, acute toxicity was evaluated on Wistar rats by OECD Guidelines for the Testing of Chemicals (Test No. 423: Acute Oral Toxicity-Class Method). Furthermore, we used the ACD/Tox Suite to predict toxicological parameters such as hERG channel blockade, CYP450 inhibition, and acute toxicity in animals. The results showed that quercetin was slightly more cytotoxic on cell lines (IC50 of 219.44 ± 7.22 mM and 465.41 ± 7.44 mM, respectively) than the other citroflavonoids. All flavonoids exhibited an LD50 value > 2000 mg/kg, which classifies them as low-risk substances as OECD guidelines established. Similarly, predicted LD50 was LD50 > 300 to 2000 mg/kg for all flavonoids as acute toxicity assay estimated. Data suggests that all these flavonoids did not show significant toxicological effects, and they were classified as low-risk, useful substances for drug development.

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Delving into the Antiurolithiatic Potential of Tribulus terrestris Extract Through –In Vivo Efficacy and Preclinical Safety Investigations in Wistar Rats

Scientific Reports ◽

10.1038/s41598-019-52398-w ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Jyoti Kaushik ◽

Simran Tandon ◽

Rishi Bhardwaj ◽

Tanzeer Kaur ◽

Surinder Kumar Singla ◽

...

Keyword(s):

Body Weight ◽

Aqueous Extract ◽

Kidney Stones ◽

Wistar Rats ◽

Lethal Dose ◽

Tribulus Terrestris ◽

Oral Toxicity ◽

Preclinical Safety

Abstract Modern treatment interventions for kidney stones are wrought with side-effects, hence the need for alternative therapies such as plant-based medicines. We have previously documented through in vitro studies that statistically optimized aqueous extract of Tribulus terrestris (Zygophyllaceae family) possesses antiurolithic and antioxidant potential. This provides strong scientific foundation to conduct in vivo efficacy and preclinical safety studies to corroborate and lend further proof to its ability to prevent and cure kidney stones. The preventive and curative urolithiatic efficacy in experimentally induced nephrolithiatic Wistar rats, along with preclinical toxicity was evaluated following oral administration of statistically optimized aqueous extract of T. terrestris. Treatment showed augmented renal function, restoration of normal renal architecture and increase in body weight. Microscopic analysis of urine revealed excretion of small sized urinary crystals, demonstrating that treatment potentially modulated the morphology of renal stones. Tissue enzymatic estimation affirmed the antioxidant efficacy of treatment with reduced free radical generation. Significant upregulation of p38MAPK at both the gene and protein level was noted in hyperoxaluric group and interestingly treatment reversed it. Acute oral toxicity study established the Median Lethal Dose (LD50) to be greater than 2000 mg/kg body weight (b.wt.) No observed adverse effect level (NOAEL) by repeated oral toxicity for 28 days at 750 mg/kg b.wt. was noted. This study lends scientific evidence to the safe, preventive and curative potential of statistically optimized aqueous extract of T. terrestris at a dose of 750 mg/kg b.wt. and suggests that the extract shows promise as a therapeutic antiurolithic agent.

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Antilymphoma Effect of Incomptine A: In Vivo, In Silico, and Toxicological Studies

Molecules ◽

10.3390/molecules26216646 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6646

Author(s):

Fernando Calzada ◽

Elihú Bautista ◽

Sergio Hidalgo-Figueroa ◽

Normand García-Hernández ◽

Elizabeth Barbosa ◽

...

Keyword(s):

Molecular Docking ◽

Acute Toxicity ◽

In Silico ◽

Docking Study ◽

Positive Control ◽

Oral Toxicity ◽

Molecular Docking Study ◽

Toxicological Studies ◽

Species Production

Incomptine A (IA) is a sesquiterpene lactone isolated from Decachaeta incompta that induces apoptosis, reactive oxygen species production, and a differential protein expression on the U-937 (diffuse histiocytic lymphoma) cell line. In this work, the antitumor potential of IA was investigated on Balb/c mice inoculated with U-937 cells and through the brine shrimp lethality (BSL) test. Furthermore, IA was subjected to molecular docking study using as targets proteins associated with processes of cancer as apoptosis, oxidative stress, and glycolytic metabolism. In addition to determining the potential toxicity of IA in human, its acute toxicity was performed in mice. Results reveals that IA showed high antilymphoma activity and BSL with an EC50 of 2.4 mg/kg and LC50 16.7 µg/mL, respectively. The molecular docking study revealed that IA has strong interaction on all targets used. In the acute oral toxicity, IA had a LD50 of 149 mg/kg. The results showed that the activities of IA including antilymphoma activity, BSL, acute toxicity, and in silico interactions were close to the methotrexate, an anticancer drug used as positive control. These findings suggest that IA may serve as a candidate for the development of a new drug to combat lymphoma.

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An Experimentally Defined Hypoxia Gene Signature in Glioblastoma and Its Modulation by Metformin

Biology ◽

10.3390/biology9090264 ◽

2020 ◽

Vol 9 (9) ◽

pp. 264

Author(s):

Marta Calvo Tardón ◽

Eliana Marinari ◽

Denis Migliorini ◽

Viviane Bes ◽

Stoyan Tankov ◽

...

Keyword(s):

Cell Lines ◽

In Silico ◽

Chemotherapy Resistance ◽

Viable Cell ◽

Gene Signature ◽

Cell Number ◽

Viable Cell Number ◽

In Silico Analyses

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor, characterized by a high degree of intertumoral heterogeneity. However, a common feature of the GBM microenvironment is hypoxia, which can promote radio- and chemotherapy resistance, immunosuppression, angiogenesis, and stemness. We experimentally defined common GBM adaptations to physiologically relevant oxygen gradients, and we assessed their modulation by the metabolic drug metformin. We directly exposed human GBM cell lines to hypoxia (1% O2) and to physioxia (5% O2). We then performed transcriptional profiling and compared our in vitro findings to predicted hypoxic areas in vivo using in silico analyses. We observed a heterogenous hypoxia response, but also a common gene signature that was induced by a physiologically relevant change in oxygenation from 5% O2 to 1% O2. In silico analyses showed that this hypoxia signature was highly correlated with a perinecrotic localization in GBM tumors, expression of certain glycolytic and immune-related genes, and poor prognosis of GBM patients. Metformin treatment of GBM cell lines under hypoxia and physioxia reduced viable cell number, oxygen consumption rate, and partially reversed the hypoxia gene signature, supporting further exploration of targeting tumor metabolism as a treatment component for hypoxic GBM.

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Prothymosin α and Its C-Terminal Immunoreactive Decapeptide Show no Evidence of Acute Toxicity: A Preliminary in Silico, in Vitro and in Vivo Investigation

Current Medicinal Chemistry ◽

10.2174/0929867328666211117093401 ◽

2021 ◽

Vol 28 ◽

Author(s):

Anastasios I. Birmpilis ◽

Panagiotis Vitsos ◽

Ioannis V. Kostopoulos ◽

Lillian Williams ◽

Kyriaki Ioannou ◽

...

Keyword(s):

Acute Toxicity ◽

In Silico ◽

Human Cancer ◽

Cell Cycle Distribution ◽

Human Cancer Cell Lines ◽

Prothymosin Α ◽

High Concentrations ◽

Immunocompetent Mice

Background: Members of the α-thymosin family have long been studied for their immunostimulating properties. Among them, the danger-associated molecular patterns (DAMPs) prothymosin α (proTα) and its C-terminal decapeptide proTα(100–109) have been shown to act as immunomodulators in vitro, due to their ability to promote T helper type 1 (Th1) responses. Recently, we verified these findings in vivo, showing that both proTα and proTα(100-109) enhance antitumor-reactive T cell-mediated responses. Methods: In view of the eventual use of proTα and proTα(100-109) in humans, we investigated their safety profile in silico, in human leukocytes and cancer cells lines in vitro, and in immunocompetent mice in vivo, in comparison to the proTα derivative thymosin alpha 1 (Τα1), a 28-mer peptide extensively studied for its safety in clinical trials. Results: In silico prediction via computational tools showed that all three peptide sequences likely are non-toxic or do not induce allergic regions. In vitro, proTα, proTα(100-109) and Tα1 did not affect the viability of human cancer cell lines and healthy donor-derived leukocytes, did not promote apoptosis or alter cell cycle distribution. Furthermore, mice injected with proTα, proTα(100-109) and Tα1 at doses equivalent to the suggested dose regimen of Tα1 in humans, did not show signs of acute toxicity, whereas proTα and proTα(100-109) increased the levels of proinflammatory and Th1-type cytokines in their peripheral blood. Conclusion: Our preliminary findings suggest that proTα and proTα(100-109), even at high concentrations, are non-toxic in vitro and in an acute toxicity model in vivo; moreover, we show that the two peptides retain their immunomodulatory properties in vivo and, eventually, could be considered for therapeutic use in humans.

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The use of Bayesian methodology in the development and validation of a tiered assessment approach towards prediction of rat acute oral toxicity

Archives of Toxicology ◽

10.1007/s00204-021-03205-x ◽

2022 ◽

Author(s):

James W. Firman ◽

Mark T. D. Cronin ◽

Philip H. Rowe ◽

Elizaveta Semenova ◽

John E. Doe

Keyword(s):

In Silico ◽

Oral Toxicity ◽

New Approach ◽

Combining Data ◽

Assessment Approach ◽

In Vivo Testing ◽

Degree Of Confidence ◽

Development And Validation

AbstractThere exists consensus that the traditional means by which safety of chemicals is assessed—namely through reliance upon apical outcomes obtained following in vivo testing—is increasingly unfit for purpose. Whilst efforts in development of suitable alternatives continue, few have achieved levels of robustness required for regulatory acceptance. An array of “new approach methodologies” (NAM) for determining toxic effect, spanning in vitro and in silico spheres, have by now emerged. It has been suggested, intuitively, that combining data obtained from across these sources might serve to enhance overall confidence in derived judgment. This concept may be formalised in the “tiered assessment” approach, whereby evidence gathered through a sequential NAM testing strategy is exploited so to infer the properties of a compound of interest. Our intention has been to provide an illustration of how such a scheme might be developed and applied within a practical setting—adopting for this purpose the endpoint of rat acute oral lethality. Bayesian statistical inference is drawn upon to enable quantification of degree of confidence that a substance might ultimately belong to one of five LD50-associated toxicity categories. Informing this is evidence acquired both from existing in silico and in vitro resources, alongside a purposely-constructed random forest model and structural alert set. Results indicate that the combination of in silico methodologies provides moderately conservative estimations of hazard, conducive for application in safety assessment, and for which levels of certainty are defined. Accordingly, scope for potential extension of approach to further toxicological endpoints is demonstrated.

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Comparison of in vitro (fish cell line) and in vivo (fish and crustacean) acute toxicity tests in aquatic toxicology

Veterinární Medicína ◽

10.17221/161/2020-vetmed ◽

2021 ◽

Author(s):

J Kolarova ◽

J Velisek ◽

Z Svobodova

Keyword(s):

Acute Toxicity ◽

Cell Line ◽

Cell Lines ◽

Poecilia Reticulata ◽

Cost Effective ◽

Neutral Red ◽

Toxicity Tests ◽

Fish Cell

The use of in vitro (fish cell lines) is a cost-effective, very rapid, and informative tool for toxicological assessments. Using the neutral red (NR) assay, we compared the in vitro acute toxicity (20hEC50) of twenty-six chemical substances on a rainbow trout gonad cell line (RTG-2) with their in vivo acute toxicity to Barbados Millions Poecilia reticulata (48hLC50, OECD 203) and crustacean Daphnia magna (48hEC50, OECD 202). The 20hEC50 values obtained by the NR assay were higher in nearly all the cases when compared to the 48hLC50 in P. reticulata and the 48hEC50 in D. magna, indicating that the sensitivity of the RTG-2 cell line was lower compared to P. reticulata and D. magna. A high (r = 0.89) and significant (P < 0.001) correlation was recorded between the 20hEC50 values of the RTG-2 and the 48hEC50 values of D. magna. The correlation between the 20hEC50 values of the RTG-2 and the 48hLC50 values of P. reticulata was lower (r = 0.65; P < 0.001), but also significant. The authors recommend use of the NR assay on the RTG-2 cell lines as a screening protocol to evaluate the toxicity of xenobiotics in aquatic environments to narrow the spectrum of the concentrations for the fish toxicity test.

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Safety Assessment of Acer tegmentosum Maxim. Water Extract: General Toxicity Studies in Sprague–Dawley Rats and Beagle Dogs With Re-evaluation of Genotoxic Potentials

Frontiers in Pharmacology ◽

10.3389/fphar.2021.687261 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jin-Sung Park ◽

Euna Kwon ◽

Yun-Soon Kim ◽

Sang-Moo Kim ◽

Dae-Sun Kim ◽

...

Keyword(s):

Acute Toxicity ◽

Clinical Signs ◽

Water Extract ◽

Deciduous Tree ◽

Human Consumption ◽

Beagle Dogs ◽

Sprague Dawley ◽

Oral Toxicity

Acer tegmentosum Maxim., commonly known as Manchurian stripe maple, is a deciduous tree belonging to the family of Aceraceae and has been traditionally used in folk medicine for its remedial effects in liver diseases and traumatic bleedings. With a growing body of experimental evidence for its pharmacological efficacies, such as neuroprotective, hepatoprotective, antioxidant, and anti-inflammatory activities, A. tegmentosum has gradually gained popularity as a health supplement and functional food. However, the large part of essential toxicity information still remained lacking despite the possibility of mutagenic potentials as previously suggested, posing safety concerns for human consumption. In this study, we evaluated 90-day repeated oral toxicity of A. tegmentosum Maxim. water extract (ATWE) in SD rats with acute toxicity assessment in beagle dogs, and reevaluated genotoxicity using a combination of in vitro and in vivo assays. During the oral study period, ATWE did not cause toxicity-related clinical signs and mortality in rodents without adverse effects observed in the analysis of hematology, serum biochemistry, and histopathology, establishing >5,000 mg/kg BW as the NOAEL. In addition, doses up to 5,000 mg/kg BW did not cause acute toxicity in beagle dogs. When assessed for genotoxicity using bacterial reverse mutation, chromosome aberration, and micronucleus formation, ATWE showed lack of mutagenicity and clastogenicity. These results demonstrated that AWTE was safe in the present preclinical study for systemic toxicity and genotoxicity at the tested doses, providing a guideline for safe use in humans.

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1,3,4-Thiadiazolo (3,2-Α) Pyrimidine-6-Carbonitrile Scaffold as PARP1 Inhibitors.

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520621666201216095018 ◽

2020 ◽

Vol 21 ◽

Author(s):

Elizabeth Eldhose ◽

Kaviarasan Lakshmanan ◽

Praveen T. Krishnamurthy ◽

Kalirajan Rajagopal ◽

Manal Mohammed ◽

...

Keyword(s):

Anticancer Activity ◽

In Silico ◽

Biological Activities ◽

Docking Study ◽

Binding Mode ◽

Oral Toxicity ◽

Standard Drug ◽

In Silico Docking

Background: 1,3,4-thiadiazolo pyrimidine is a lead molécule which is versatile for a wide variety of biological activities and in continuation of our interest in establishing some novel heterocyclic compounds for antitumor activity. Objective: The objective of the study was to synthesize series of 5-amino-7-(substituted aldehyde)-2[(naphthalene-2-yloxy)methyl] - [1,3,4]thiadiazolo-[3,2-α]-pyrimidine-6- carbonitrile derivative and evaluated for their possible in vitro and in vivo anticancer activity. Methods: Herein we report the synthetic scheme which was followed for the preparation of a series of title compounds B1- B9 is outlined in the scheme 1. The intermediate 5-[(naphthalen-2- yloxy)methyl]-1,3,4-thiadiazolo-2-amine was prepared by heating 2-naphthoxyacetic acid and thiosemicarbazide in presence of phosphoryl chloride at a temperature of 65 - 750C. The obtained compound reacted with malononitrile and appropriate amount of aromatic and heteroaromatic aldehydes in refluxing ethanol yielded 5-amino-7-(substituted aldehyde)-2[(naphthalene-2-yloxy)methyl] -[1,3,4]thiadiazolo-[3,2-α]-pyrimidine-6- carbonitrile derivatives (B1 – B9). The purity of synthesized compounds ensured by various spectral analysis. Results: In in-silico molecular docking studies compounds B3 and B9 show binding affinity like known PARP1 inhibitor olaparib. The cellular evaluation indicates that the anticancer activity of compounds B1, B3, B9 is significant when compared to standard drug (olaparib) against MDA-MB-232 cell line and compounds B3, B6, B7 are most active against MCF-7 cell lines. The most active compound B3 was subjected to acute oral toxicity studies by OECD 423 guidelines and in-vivo anti-cancer studies were carried out using DMBA induced model. Conclusion: The in-silico docking study of the newly synthesized compounds were performed, the results showed good binding mode in the active site of PARP1 enzyme. In-silico ADME properties of synthesized compounds were also studied and showed good drug like properties.

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Phytochemicals from Rhizophora mucronata Propagules, Its In Vitro Anti-Cancer and In Silico Drug-Likeness Potential

Chemistry ◽

10.3390/chemistry3030070 ◽

2021 ◽

Vol 3 (3) ◽

pp. 979-990

Author(s):

Nurhanan Murni Yunos ◽

Sui Kiong Ling ◽

Asiah Osman ◽

Zunoliza Abdullah ◽

Nor Jannah Sallehudin

Keyword(s):

Cell Lines ◽

Cancer Cell ◽

In Silico ◽

Quinic Acid ◽

Cancer Cell Lines ◽

Rhizophora Mucronata ◽

Toxicological Effects ◽

Ic50 Values ◽

Caffeoyl Quinic Acid

This is the first report to identify the presence of 3-O-caffeoyl quinic acid (1), 4-O-caffeoyl quinic acid (2), 5-O-caffeoyl quinic acid (3), epi-catechin (4), and procyanidin B2 (5) in the young propagules of Rhizophora mucronata. Compounds 2–5 were purified and then treated against breast, colorectal, and ovarian cancer cell lines for 72 h and the results of the Sulphorhodomine-B (SRB) assay were evaluated for percent cell viability and IC50 values. Epi-catechin, 4-O-caffeoyl quinic acid, 5-O-caffeoyl quinic acid and procyanidin B2 showed strong to moderate inhibitory effects when treated on breast (T47D), colorectal (HT29), and ovarian (A2780, SKOV3) cancer cell lines with IC50 values ranging from 16.77 ± 0.58 to 28.28 ± 0.89 μg/mL. In silico evaluation was performed to evaluate the drug-likeness and toxicological effects of these compounds using Molinspiration calculation and OSIRIS program. It was found that compounds 2, 3, and 4 have the potential to be orally active and have a low risk in exerting the mutagenic, tumorigenic, irritant, and reproductive effects.

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Challenges and Opportunities for Integrating In Silico Models and Adverse Outcomes Pathways to Set and Relate New Biomarkers

Water ◽

10.3390/w12123549 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3549

Author(s):

Carlos E. Matos dos Santos ◽

Raul Ghiraldelli Miranda ◽

Danielle Palma de Oliveira ◽

Daniel Junqueira Dorta

Keyword(s):

In Silico ◽

Ex Vivo ◽

Adverse Outcomes ◽

Adverse Outcome Pathway ◽

Biological Organization ◽

Toxicological Effects ◽

New Biomarkers ◽

In Silico Models

The Adverse Outcome Pathway (AOP) framework has been considered the most innovative tool to collect, organize, and evaluate relevant information on the toxicological effects of chemicals, facilitating the establishment of links between molecular events and adverse outcomes at the critical level of biological organization. Considering the combination of the high volume of toxicological and ecotoxicological data produced and the application of artificial intelligence algorithms from the last few years, not only can higher mechanistic interpretability be reached with new in silico models, but also a potential increase in predictivity in hazard assessments and the identification of new potential biomarkers can be achieved. The current paper aims to discuss some potential challenges and ways of integrating in silico models and AOPs to predict toxicological effects and to set and relate new biomarkers for defined purposes. With the use of the AOP framework to organize the ecotoxicological, toxicological, and structural data generated from in chemico, in vitro, ex vivo, in vivo, and population studies, it is expected that the generated biological and chemical construct will improve its application, establishing a knowledge platform to set and relate new biomarkers by key event relationships (KERs).

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