Sanguinarine: an evaluation of in vivo cytogenetic activity

Safety and efficacy of a feed additive consisting of Macleaya cordata (Willd.) R. Br. extract and leaves (Sangrovit® extra) for all poultry species (excluding laying and breeding birds) (Phytobiotics Futterzusatzstoffe GmbH)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Macleaya cordata (Willd.) R. Br. extract and leaves (Sangrovit® Extra) when used as a zootechnical feed additive (functional group: other zootechnical additives) for all poultry species (excluding laying and breeding birds). The additive is standardised to contain a concentration of the sum of the four alkaloids sanguinarine, chelerythrine, protopine and allocryptopine of 1.25%, with 0.5% sanguinarine. Owing to the presence of the DNA intercalators sanguinarine and chelerythrine, a concern for genotoxicity was identified. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) had no safety concerns when the additive is used at the recommended level of 150 mg/kg complete feed (corresponding to 0.750 mg sanguinarine/kg complete feed) for chickens for fattening and other poultry species for fattening. No conclusion can be drawn for poultry reared for laying/breeding. The use of Sangrovit® Extra in poultry species for fattening at the maximum recommended level was considered of low concern for consumers. The additive was shown to be irritant to the eyes but not irritant to skin or a skin sensitiser. The FEEDAP Panel could not exclude the potential of the additive to be a respiratory sensitiser. When handling the additive, exposure of unprotected users to sanguinarine and chelerythrine may occur. Therefore, to reduce the risk, the exposure of users should be reduced. The use of Sangrovit® Extra as a feed additive under the proposed conditions of use was considered safe for the environment. The additive Sangrovit® Extra had the potential to be efficacious in improving performance of chickens for fattening at 45 mg/kg complete feed. This conclusion was extended to chickens reared for laying/breeding and extrapolated to all poultry species for fattening or reared for laying/breeding.

Naturally occurring quaternary benzo[c]phenanthridine alkaloids selectively stabilize G-quadruplexes

In this work, the interaction of six natural benzo[c]phenanthridine alkaloids (macarpine, sanguilutine, sanguirubine, chelerythrine, sanguinarine and chelirubine) with parallel and antiparallel G-quadruplex DNA structures was studied.

Molecular targets and anticancer potential of sanguinarine-a benzophenanthridine alkaloid

BACKGROUND

Cancer is an enormous global health burden, and should be effectively addressed with better therapeutic strategies. Currently, over 60% of the clinically approved anticancer agents are either directly isolated from natural sources or are modified from natural lead molecules. Sanguinarine (SNG), a quaternary benzophenanthridine alkaloid has gained increasing attention in recent years as a potential anticancer agent.

PURPOSE

There is a large untapped source of phytochemical-based anticancer agents remaining to be explored. This review article aims to recapitulate different anticancer properties of SNG, and describes some of the molecular targets involved in exerting its effect. It also depicts the pharmacokinetic and toxicological properties of SNG, two parameters important in determining the druggability of a molecule.

METHODS

Numerous in vivo and in vitro published studies have signified the anticancer properties of SNG. In order to collate and decipher these properties, an extensive literature search was conducted in PubMed, ScienceDirect, and Scopus using keywords followed by the evaluation of the relevant articles where the relevant reports are integrated and analyzed.

RESULTS

Apart from inducing cell death, SNG inhibits pro-tumorigenic processes such as invasion, angiogenesis, and metastasis in different cancers. Moreover, SNG has been shown to synergistically enhance the sensitivity of several chemotherapeutic agents and is effective against a variety of multi-drug resistant cancers.

Carcinogenic potential of sanguinarine, a phytochemical used in 'therapeutic' black salve and mouthwash

Black salves are escharotic skin cancer therapies in clinical use since the mid 19th century. Sanguinaria canadensis, a major ingredient of black salve formulations, contains a number of bioactive phytochemicals including the alkaloid sanguinarine. Despite its prolonged history of clinical use, conflicting experimental results have prevented the carcinogenic potential of sanguinarine from being definitively determined. Sanguinarine has a molecular structure similar to known polyaromatic hydrocarbon carcinogens and is a DNA intercalator. Sanguinarine also generates oxidative and endoplasmic reticulum stress resulting in the unfolded protein response and the formation of 8-hydroxyguanine genetic lesions. Sanguinarine has been the subject of contradictory in vitro and in vivo genotoxicity and murine carcinogenesis test results that have delayed its carcinogenic classification. Despite this, epidemiological studies have linked mouthwash that contains sanguinarine with the development of oral leukoplakia. Sanguinarine is also proposed as an aetiological agent in gallbladder carcinoma. This literature review investigates the carcinogenic potential of sanguinarine. Reasons for contradictory genotoxicity and carcinogenesis results are explored, knowledge gaps identified and a strategy for determining the carcinogenic potential of sanguinarine especialy relating to black salve are discussed. As patients continue to apply black salve, especially to skin regions suffering from field cancerization and skin malignancies, an understanding of the genotoxic and carcinogenic potential of sanguinarine is of urgent clinical relevance.

Argemone oil induces genotoxicity in mice

CONTEXT

Argemone mexicana L. is native to Mexico and the plant extracts are used in traditional medicine in India and South American countries. Argemone oil (AO) is a common adulterant of mustard oil in India and causes serious pathophysiological consequences leading to outbreaks of epidemic dropsy among consumers. In vivo cytogenetic studies on the toxicological effects of AO and its component alkaloids are limited.

OBJECTIVE

The present study was undertaken to evaluate the safety of AO by assessment of their in vivo genotoxic potential in bone marrow cells of mice.

MATERIALS AND METHODS

AO mixed in corn oil in the proportions of 0.01, 0.1, and 1 ml AO/kg body weight in a total volume of 10 ml/kg body weight and a single undiluted dose of AO (10 ml/kg body weight) were administered intraperitoneally in separate groups of male Swiss Albino mice for 24 h. In addition, a single concentration of sanguinarine (SG) (50 mg/kg body weight) was also administered. Genotoxicity was evaluated by chromosome aberration (CA) and sister chromatid exchange (SCE) tests. Bromodeoxyuridine (BrdU) differential technique was used to study the effect on cell replication by the calculation of average generation time (AGT).

RESULTS

The minimum effective concentrations that produced significant frequencies of CA and SCE were 0.1 and 0.01 ml/kg, respectively. AO and SG induced an insignificant increase of AGT indicating that they are non-cytotoxic in the concentrations tested.

DISCUSSION AND CONCLUSION

Our results confirm that AO is genotoxic even at low concentrations and its usage should be checked.

In vitro and in vivo genotoxicity of silver nanoparticles

The biocidal effect of silver nanoparticles (Ag-np) has resulted in their incorporation into consumer products. While the population exposed to Ag-np continues to increase with ever new applications, Ag-np remains a controversial research area with regard to their toxicity in biological systems. Here a genotoxic and cytotoxic approach was employed to elucidate the activity of Ag-np in vitro and in vivo. Characterization of Ag-np using scanning electron microscopy revealed a size range of 90-180nm. Cytotoxic potential of Ag-np was evaluated in human lymphocytes via cell viability assay (Trypan blue dye exclusion method, MTT and WST assay). The uptake and incorporation of Ag-np into the lymphocytes was confirmed by flow cytometry. Additionally apoptosis (AnnexinV-FITC-PI staining) and DNA strand breaks (comet assay) in human lymphocytes revealed that Ag-np at concentration 25μg/ml can cause genotoxicity. In vivo experiments on plants (Allium cepa and Nicotiana tabacum) and animal (Swiss albino male mice) showed impairment of nuclear DNA. Induction of oxidative stress was also studied. The DNA damage and chromosomal aberrations raise the concern about the safety associated with applications of the Ag-np. A single ip administration of Ag-np gave a significant (P≤0.05) increase in the frequency of aberrant cells and Tail DNA percent at concentrations 10mg/kg body weight and above. Results of comet assay in A. cepa and N. tabacum demonstrated that the genotoxic effect of Ag-np was more pronounced in root than shoot/leaf of the plants. The present study indicated a good correlation between the in vitro and in vivo experiments. Therefore the biological applications employing Ag-np should be given special attention besides adapting the antimicrobial potential.

Genotoxicity evaluation of 4-carboxyl- 2,6-dinitrophenylazohydroxynaphthalenes in mice

A short-term in vivo genotoxicity evaluation of 4-carboxyl-2,6-dinitrophenylazohydronaphthalenes (AZ-01 to AZ-04) has been carried out in mice. Aqueous colloidal solutions of the dyes were administered to mice on each day for 5 successive days using gastric gavages. Two end point assessments of the genotoxicity potentials of the dyes were assessed using comet assay and chromosomal aberration studies using the mice bone marrow cells. The dyes were well tolerated at the doses investigated, as there were no deaths or any adverse pharmacotoxic events. Dose-dependent DNA damage (in terms of percentage of tail DNA and Olive tail moment) occurred with AZ-01 and AZ-02, although the effects were significant only with the highest doses. AZ-03 gave similar patterns with those of AZ-01 and AZ-02, while replacement with butanone in AZ-04 altered the observed pattern. Minimal chromosomal damages were obtained for the four dyes, with AZ-01 and AZ-02 giving nonsignificant damages, while the highest dose of AZ-03 produced significant aberrations in terms of breaks. Some minor isochromatid breaks and gaps were also noticed in the dye-treated mice. Mitotic indices in all cases were not significantly different from concomitantly administered vehicle control showing lack of cytotoxicity of the monoazo dyes at these doses. The monoazo dyes show the potential of being utilized as colorants, pending further required tests.

Antitumor effects of the benzophenanthridine alkaloid sanguinarine in a rat syngeneic model of colorectal cancer

To evaluate the in-vivo preclinical antitumor activity of sanguinarine in a rat syngeneic model of colorectal cancer. The effects of sanguinarine on DHD/K12/TRb colorectal adenocarcinoma cells were first evaluated in vitro by means of ³H-thymidine incorporation, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay, and terminal transferase dUTP nick end labeling (TUNEL) microscopy. For the in-vivo studies, DHD/K12/TRb cells (1.5 × 10⁶ cells/0.3 ml of sterile saline/animal) were injected subcutaneously in syngeneic BDIX rats, which were chronically treated with sanguinarine (5 mg/kg/day per os) or control diluent. Tumor growth, body weight, hematologic, and clinical chemistry measurements were monitored in individual animals at defined time intervals. After killing, subcutaneous tumors were explanted from experimental animals for histopathological examination. In vitro, micromolar concentrations of sanguinarine inhibited dose-dependently DHD/K12/TRb cell proliferation and metabolism and induced cell death by apoptosis. In vivo, oral administration of sanguinarine induced a significant inhibition of tumor growth (P<0.01 vs. untreated controls), in the absence of any toxic or side effects. Marked apoptosis and reduced peritumoral vascularization were observed in tumors from sanguinarine-treated rats as compared with the controls. Additional basic studies are needed to fully characterize the mechanism/s underlying the inhibitory effects of sanguinarine on angiogenesis and tumor growth as well as the pharmacological and safety profile of this drug in experimental tumor models. Overall, findings from this study suggest that sanguinarine is a likely candidate for further evaluation in cancer therapy.

Sanguinarine suppresses prostate tumor growth and inhibits survivin expression

Prostate cancer is a frequently occurring disease and is the second leading cause of cancer-related deaths of men in the United States. Current treatments have proved inadequate in curing or controlling prostate cancer, and a search for agents for the management of this disease is urgently needed. Survivin plays an important role in both progression of castration-resistant prostate cancer and resistance to chemotherapy. Altered expression of survivin in prostate cancer cells is associated with cancer progression, drug/radiation resistance, poor prognosis, and short patient survival. In the present study, the authors performed a cell-based rapid screen of the Prestwick Chemical Library consisting of 1120 Food and Drug Administration-approved compounds with known safety and bioavailability in humans to identify potential inhibitors of survivin and anticancer agents for prostate cancer. Sanguinarine, a benzophenanthridine alkaloid derived primarily from the bloodroot plant, was identified as a novel inhibitor of survivin that selectively kills prostate cancer cells over "normal" prostate epithelial cells. The authors found that sanguinarine inhibits survivin protein expression through protein degradation via the ubiquitin-proteasome system. Sanguinarine induces apoptosis and inhibits growth of human prostate cancer cells and in vivo tumor formation. Administration of sanguinarine, beginning 3 days after ectopic implantation of DU145 human prostate cancer cells, reduces both tumor weight and volume. In addition, sanguinarine sensitized paclitaxel-mediated growth inhibition and apoptosis, offering a potential therapeutic strategy for overcoming taxol resistance. These results suggest that sanguinarine may be developed as an agent either alone or in combination with taxol for treatment of prostate cancer overexpressing survivin.

High-altitude medicines: A short-term genotoxicity study

People live in the mountains distributed across the world and are exposed to reduced inspired oxygen and lower barometric pressure along with other factors that lead to high-altitude diseases. The present study was conducted to examine what extent of marketed medicines used in the management of high-altitude sickness has been tested for their genotoxic activity. Comet assay or the single-cell gel electrophoresis was utilized to evaluate genotoxicity of the six medicines on human peripheral whole blood cells and isolated lymphocytes at the concentrations 250 μg/mL, 500 μg/mL and 1 mg/mL. The comet assay endpoints included percentage Tail DNA (% Tail DNA) and olive tail moment (OTM) as they were considered to be sensitive and reliable scores across different laboratories. The results show that dexamethasone, deriphylline and furosemide can induce significant DNA damage in human whole blood and lymphocytes alike. Acetazolamide, ibuprofen and nifedipine show no genotoxic effect, neither on human whole blood nor on human lymphocytes. Taking into account the results of genotoxicity, it will be a prudent choice to restrict the use of these compounds for longer periods, until more information on the in vitro mutagenicity and in vivo genotoxicity studies are available.

Sanguinarine cytotoxicity on mouse melanoma K1735-M2 cells--nuclear vs. mitochondrial effects

Sanguinarine (SANG) is an alkaloid recognized to have anti-proliferative activity against various human tumour cell lines. No data is available on the susceptibility of advanced malignant melanoma to SANG, although this disease has a very poor prognosis if not detected in time due to the resistance to conventional chemotherapy. The present work was designed to study the nuclear and mitochondrial involvement in the pro-apoptotic effect of SANG in an invasive mouse melanoma cell line. The results obtained show that SANG is primarily accumulated by the cell nuclei, causing inhibition of cell proliferation and inducing cell death, as confirmed by an increase in sub-G1 peaks. At low concentrations, SANG induces mitochondrial depolarization in a sub-population of melanoma cells, which also generally displayed strong nuclear labelling of phosphorylated histone H2AX. Western blotting revealed an increase in p53, but not Bax protein, in both whole-cell extracts and in mitochondrial fractions. Isolated hepatic mitochondrial fractions revealed that SANG affects the mitochondrial respiratory chain, and has dual effects on mitochondrial calcium loading capacity. We suggest that SANG is able to induce apoptosis in metastatic melanoma cells. The knowledge of mitochondrial vs. nuclear effects of SANG is important in the development of this promising compound for clinical use against aggressive melanoma.

DNA-binding affinities and sequence selectivity of quaternary benzophenanthridine alkaloids sanguinarine, chelerythrine, and nitidine

A comparative study on the intercalating binding of sanguinarine, chelerythrine, and nitidine with CT DNA, poly(dG-dC).poly(dG-dC), poly(dA-dT).poly(dA-dT), and seven sequence-designed double-stranded oligodeoxynucleotides has been performed using fluorometric and spectrophotometric techniques, aiming at providing insights into their sequence selectivity for DNA-binding. The results show that both sanguinarine and nitidine bind preferentially to DNA containing alternating GC base pairs [d(TGCGCA)(2)], while chelerythrine exhibits quite distinct sequence selectivity from sanguinarine, which shows a high specificity for DNA containing contiguous GC base pairs [5'-TGGGGA-3'/3'-ACCCCT-5'].

The plant alkaloid Sanguinarine affects swine granulosa cell activity

Sanguinarine (SA) has been used in toothpastes and oral rinse products and has been recently applied to livestock nutrition. This study was undertaken to examine the reproductive-related consequences of this feeding supplementation, evaluating SA effects (10, 100 and 300 nM) on swine granulosa cell steroidogenesis, oxidative enzyme activities (peroxidase, catalase and superoxide dismutase), and proliferation. Since angiogenesis is fundamental for follicle development, we also tested the impact of SA exposure on vascular endothelial growth factor (VEGF) production. SA had no effect on proliferation and did not alter progesterone production, although it significantly reduced estradiol synthesis at the two highest concentrations tested (100 and 300 nM). SA addition to granulosa cell culture inhibited VEGF production and increased peroxidase and catalase activities at all tested concentrations while superoxide dismutase activity was increased only at 300 nM. Our data suggest that SA can negatively affect some key biochemical parameters of ovarian granulosa cells.