Correlation of DNA damage in epidemic dropsy patients to carcinogenic potential of argemone oil and isolated sanguinarine alkaloid in mice

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.

Advanced techniques in edible oil authentication: A systematic review and critical analysis

Adulteration of edible substances is a potent contemporary food safety issue. Perhaps the overt concern derives from the fact that adulterants pose serious ill effects on human health. Edible oils are one of the most adulterated food products. Perpetrators are adopting ways and means that effectively masks the presence of the adulterants from human organoleptic limits and traditional oil adulteration detection techniques. This review embodies a detailed account of chemical, biosensors, chromatography, spectroscopy, differential scanning calorimetry, non-thermal plasma, dielectric spectroscopy research carried out in the area of falsification assessment of edible oils for the past three decades and a collection of patented oil adulteration detection techniques. The detection techniques reviewed have some advantages and certain limitations, chemical tests are simple; biosensors and nuclear magnetic resonance are rapid but have a low sensitivity; chromatography and spectroscopy are highly accurate with a deterring price tag; dielectric spectroscopy is rapid can be portable and has on-line compatibility; however, the results are susceptible to variation of electric current frequency and intrinsic factors (moisture, temperature, structural composition). This review paper can be useful for scientists or for knowledge seekers eager to be abreast with edible oil adulteration detection techniques.

Celecoxib reduces Deoxynivalenol induced proliferation, inflammation and protein kinase C translocation via modulating downstream targets in mouse skin

Exposure to mycotoxins is mostly by ingestion but also occurs by the dermal and inhalation routes. The present study for the first time demonstrated that mycotoxin Deoxynivalenol (DON), permeates through Swiss albino mice skin, which demands awareness of health risks in people who are dermally exposed to mycotoxins especially agricultural farmers. Despite the widespread contamination of DON in food commodities studies to alleviate DON's toxicity are sparsely reported. Thus effective measures to combat mycotoxins associated toxicity remains an imperative aspect to be considered from the angle of dermal exposure. Topical application of Celecoxib (1-2 mg), followed by DON (100 μg) application on the dorsal side of mice, resulted in substantial decrease in DON-induced (i) edema, hyperplasia, cell proliferation (ii) inhibition of cytokine and prostaglandin-E2 levels (iii) phosphorylation of ERK1/2, JNK, p38, MAPKKs, CREB, P90-RSK (iv) downregulation of c-Jun, c- Fos, phospho-NF-kB and their downstream target proteins cyclin D1 and COX-2. Using Ro-31-8220 (Protein-Kinase-C inhibitor), it was observed PKC was responsible for DON induced upregulation of COX-2 and iNOS proteins. Treatment of Celecoxib decreased DON-induced translocation of Protein Kinase C isozymes (α,ε,γ), demonstrating the role of PKC in DON-mediated biochemical and molecular alterations responsible for its dermal toxicity. The present findings indicate that topical application of celecoxib is effective in the management of inflammatory skin disorders induced by foodborne fungal toxin DON. The skin permeation potential of Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor NSAID, was also assessed, and the results indicated that the permeation was relatively lower as compared to the oral mode of administration. Hence topical use of celecoxib may be preferred over oral dosing because of lower systemic absorption and to avoid the unwanted side effects. This study provides a prospect for exploring the clinical efficacy of topically applied COX-2 inhibitors for the management of inflammatory skin disorders induced by foodborne fungal toxins.

A Study on Redox Potential of Phytochemicals and their Impact on DNA

The phytochemicals are endowed with antioxidant activities because of the presence of plentiful polyphenols and many other phytochemicals. However, some recent reports have suggested that phytochemicals from certain plant species exhibit DNA damaging properties mainly due to presence of alkaloids. In the present study, pBR322, Salmonella typhi DNA, insect DNA and human DNA were treated with hexanolic extract of Argemone mexicana and Thevesia peruviana leaves to assess their DNA damaging abilities. Another set of experiments was carried out using the methanolic extracts of Citrus lemon leaves to assess their DNA protecting abilities from damage of DNA by extracts of A. mexicana and T. peruviana at 150000 ppm for all DNAs used. The results indicated that the leaves extract of A. mexicanaand T. peruviana demonstrated significant DNA damaging potential at higher concentrations. In contrast, the extracts from C. limonat 15000 ppm showed maximum DNA protective properties for all DNAs used.

IGFBP-3 Is the Key Target of Sanguinarine in Promoting Apoptosis in Hepatocellular Carcinoma

Introduction

Chemotherapeutic treatment of hepatocellular carcinoma (HCC) has always been plagued by nonspecific and side effects. Plant extracts have potential anticancer capabilities with low cytotoxicity and few side effects, but their detailed mechanisms are still unclear, thus limiting their clinical applications.

Methods

In this study, five plant extracts were chosen, their inhibition on HCC cell viability was compared by CCK-8 assay and sanguinarine (SAN) was selected. Then, wound healing assay, transwell assay, and apoptosis assay were carried out in Hep3B cells. Bioinformatics methods were performed and IGFBP-3 was predicted the targets of SAN in HCC. The mechanism of SAN regulating IGFBP-3 was explored using qRT-PCR, Western blotting, cell viability assay and apoptosis assay. Meanwhile, knockdown of IGFBP-3 were used by small interfering RNA (siRNA).

Results

In five plant extracts, SAN inhibited the proliferation of HCC cell lines most considerably. In addition, apoptosis was promoted, and invasion and migration were inhibited in the Hep3B cell line by treatment with SAN at 2 μM. Bioinformatics indicated that SAN could affect HCC apoptosis through the TP53/IGFBP-3 pathway, and further verification experiments showed that SAN upregulated the expression of insulin-like growth factor binding protein-3 (IGFBP-3) in the Hep3B cell line; SAN also inhibited the expression of Bcl-2 and promoted the expression of BAX and caspase-3. After using siRNA to inhibit the expression of IGFBP-3, the effect of SAN was blocked.

Conclusion

Our study further reveals a novel mechanism that IGFBP-3 is an important target of SAN, by upregulating expression of IGFBP-3, SAN promotes apoptosis in HCC.

Cytotoxic and Proapoptotic Activity of Sanguinarine, Berberine, and Extracts of Chelidonium majus L. and Berberis thunbergii DC. toward Hematopoietic Cancer Cell Lines

Isoquinoline alkaloids belong to the toxic secondary metabolites occurring in plants of many families. The high biological activity makes these compounds promising agents for use in medicine, particularly as anticancer drugs. The aim of our study was to evaluate the cytotoxicity and proapoptotic activity of sanguinarine, berberine, and extracts of Chelidonium majus L. and Berberis thunbergii DC. IC10, IC50, and IC90 doses were established toward hematopoietic cancer cell lines using trypan blue staining. Alterations in the expression of 18 apoptosis-related genes in cells exposed to IC10, IC50, and IC90 were evaluated using real-time PCR. Sanguinarine and Chelidonium majus L. extract exhibit significant cytotoxicity against all studied cell lines. Lower cytotoxic activity was demonstrated for berberine. Berberis thunbergii DC. extract had no influence on cell viability. Berberine, sanguinarine, and Chelidonium majus L. extract altered the expression of apoptosis-related genes in all tested cell lines, indicating the induction of apoptosis. The presented study confirmed the substantial cytotoxicity and proapoptotic activity of sanguinarine, berberine, and Chelidonium majus L. extract toward the studied hematopoietic cell lines, which indicates the utility of these substances in anticancer therapy.

The Comet Assay: Assessment of In Vitro and In Vivo DNA Damage

Anthropogenic activities, indiscriminate and rapid industrialization as well as pursuance of a better life has led to an increase in the concentration of chemicals, like pesticides, automobile exhausts, and new chemical entities, in the environment, which have an adverse effect on all living organisms including humans. Sensitive and robust test systems are thus required for accurate hazard identification and risk assessment. The Comet assay has been used widely as a simple, rapid, and sensitive tool for assessment of DNA damage in single cell from both in vitro and in vivo sources as well as in humans. The advantages of the in vivo Comet assay are its ability to detect DNA damage in any tissues, despite having non-proliferating cells, and its sensitivity to detect genotoxicity. The recommendations from the international workshops held for the Comet assay have resulted in establishment of guidelines, and the OECD has adopted a guideline for the in vivo Comet assay as a test for assessing DNA damage in animals. The in vitro Comet assay conducted in cultured cells can be used for screening large number of compounds and at very low concentrations. The in vitro assay has also been automated to provide a high throughput screening method for new chemical entities, as well as in environmental samples. This chapter details the in vitro Comet assay using the 96-well plate and in vivo Comet assay in multiple organs of the mouse.

Argemone oil, an edible oil adulterant, induces systemic immunosuppression in Balb/c mice in an oral 28 days repeated dose toxicity study

Consumption of edible oils contaminated with Argemone oil (AO) leads to a clinical condition called "Epidemic dropsy". Earlier studies have reported that metabolism and oxidative stress primarily contributes to AO toxicity, however, the involvement of immune system has not been assessed so far. Therefore, the present study was undertaken to systematically assess the effect of AO exposure on the function of immune system in Balb/c mice. The repeated exposure of AO for 28 days caused prominent regression of spleen and thymus; severe inflammatory changes in spleen depicted by the loss of distinct follicles, increased megakaryocyte infiltration, and enhanced expression levels of inflammatory markers (iNOS & COX-2). At the functional level, AO exposure significantly abrogated the mixed lymphocyte reaction and mitogen-stimulated lymphoproliferative activity of T and B cells, which is reflective of profound lymphocyte dysfunction upon antigen exposure. In concordance with the loss in functional activity of lymphocytes in AO exposed animals, it was found the AO altered the relative percentage of CD3⁺, CD4⁺, and CD28 ⁺ T cells. Further, there was a marked decrease in the relative distribution of cells with prominent MHC I and CD1d expression in AO exposed splenocytes. Moreover, reduced levels of immune stimulatory cytokines (TNF-α, IFN-γ, IL-2, IL-4, and IL-6), and increased levels of immunosuppressive cytokine IL-10 were detected in the serum of AO treated mice. Along with T and B cells, AO exposure also affected the phenotype and activation status of macrophages suggesting the inclination towards "alternative activation of macrophages". Altogether, these functional changes in the immune cells are contributing factors in AO induced immunosuppression.

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.

Anticancer potential of sanguinarine for various human malignancies

Sanguinarine (Sang) - a benzophenanthridine alkaloid extracted from Sanguinaria canadensis - exhibits antioxidant, anti-inflammatory, proapoptotic and growth inhibitory activities on tumor cells of various cancer types as established by in vivo and in vitro studies. Although the underlying mechanism of Sang antitumor activity is yet to be fully elucidated, Sang has displayed multiple biological effects, which remain to suggest its possible use in plant-derived treatments of human malignancies. This review covers the anticancer abilities of Sang including inhibition of aberrantly activated signal transduction pathways, induction of cell death and inhibition of cancer cell proliferation. It also highlights Sang-mediated inhibition of angiogenesis, inducing the expression of tumor suppressors, sensitization of cancer cells to standard chemotherapeutics to enhance their cytotoxic effects, while addressing the present need for further pharmacokinetic-based studies.

Antitumor effects of the benzophenanthridine alkaloid sanguinarine: Evidence and perspectives

Historically, natural products have represented a significant source of anticancer agents, with plant-derived drugs becoming increasingly explored. In particular, sanguinarine is a benzophenanthridine alkaloid obtained from the root of Sanguinaria canadensis, and from other poppy Fumaria species, with recognized anti-microbial, anti-oxidant and anti-inflammatory properties. Recently, increasing evidence that sanguinarine exibits anticancer potential through its capability of inducing apoptosis and/or antiproliferative effects on tumor cells, has been proved. Moreover, its antitumor seems to be due not only to its pro-apoptotic and inhibitory effects on tumor growth, but also to its antiangiogenic and anti-invasive properties. Although the precise mechanisms underlying the antitumor activity of this compound remain not fully understood, in this review we will focus on the most recent findings about the cellular and molecular pathways affected by sanguinarine, together with the rationale of its potential application in clinic. The complex of data currently available suggest the potential application of sanguinarine as an adjuvant in the therapy of cancer, but further pre-clinical studies are needed before such an antitumor strategy can be effectively translated in the clinical practice.

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.

Benzanthrone induced immunotoxicity via oxidative stress and inflammatory mediators in Balb/c mice

Benzanthrone (BA) is an important dye intermediate which is used in the manufacturing of several polycyclic vat and disperse dyes in textile industries. Several studies have indicated that the general population is also exposed to BA owing to its release from furnace effluents and automobile exhausts in the environment. In several clinical studies, it has been shown that workers exposed to BA developed itching, burning sensation, erythema and hyperpigmentation of the skin, which could be an outcome of the dysregulated immune response. In this study, we have used female Balb/c mice as a model to study the immuno-inflammatory changes after systemic administration of BA (7.5mg/kgb.w. and 15mg/kgb.w.) for one week. BA exposed animals exhibited the signs of intense systemic inflammation as evident by enhanced DTH response, MPO activity, hyperplastic and dysplastic histopathological organization of spleen and lung tissue. Splenic evaluation revealed enhanced oxidative stress, upregulation of prominent inflammatory markers like iNOS and COX-2 and DNA damage. In coherence with the observed immuno-inflammatory alterations, the levels of several inflammatory and regulatory cytokines (IL-17, TNF-α, IFN-γ, IL-1, IL-10, IL-4) were significantly enhanced in serum as well as the spleen. In addition, BA administration significantly induced the activation of ERK1/2, p38, JNK MAPKs and their downstream transcription factors AP-1 (c-fos, c-jun), NF-κB and Nrf2 which comprise important mechanistic pathways involved in inflammatory manifestations. These results suggest the immunotoxic nature of the BA and have implications for the risk assessment and management of occupational workers, and even common masses considering its presence as an environmental contaminant.

Multiple mechanisms of cell death induced by chelidonine in MCF-7 breast cancer cell line

In a preliminary study screening anti-proliferative natural alkaloids, a very potent benzophenanthridine, chelidonine showed strong cytotoxicity in cancer cells. While several modes of death have been identified, most of anti-cancer attempts have focused on stimulation of cells to undergo apoptosis. Chelidonine seems to trigger multiple mechanisms in MCF-7 breast cancer cells. It induces both apoptosis and autophagy modes of cell death in a dose dependent manner. Alteration of expression levels of bax/bcl2, and dapk1a by increasing concentration of chelidonine approves switching the death mode from apoptosis induced by very low to autophagy by high concentrations of this compound. On the other hand, submicromolar concentrations of chelidonine strongly suppressed telomerase at both enzyme activity and hTERT transcriptional level. Long exposure of the cells to 50 nanomolar concentration of chelidonine considerably accelerated senescence. Altogether, chelidonine may provide a promising chemistry from nature to treat cancer.

Mechanisms of Mycotoxin-induced Dermal Toxicity and Tumorigenesis Through Oxidative Stress-related Pathways

Among the many mycotoxins, T-2 toxin, citrinin (CTN), patulin (PAT), aflatoxin B1 (AFB1) and ochratoxin A (OTA) are known to have the potential to induce dermal toxicity and/or tumorigenesis in rodent models. T-2 toxin, CTN, PAT and OTA induce apoptosis in mouse or rat skin. PAT, AFB1 and OTA have tumor initiating properties, and OTA is also a tumor promoter in mouse skin. This paper reviews the molecular mechanisms of dermal toxicity and tumorigenesis induced in rodent models by these mycotoxins especially from the viewpoint of oxidative stress-mediated pathways.

Protective effect of topical application of α-tocopherol and/or N-acetyl cysteine on argemone oil/alkaloid-induced skin tumorigenesis in mice

Since bioantioxidants in plasma of Epidemic Dropsy patients [a condition caused by consumption of adulterated mustard oil with argemone oil (AO)] were found to be significantly decreased, the beneficial effect of N-acetyl cysteine (NAC) and α-tocopherol (TOCO) against AO- or sanguinarine (SANG)-induced tumorigenicity was undertaken in mice. Topical application of TOCO and NAC either alone or in combination showed significant protection against AO/TPA- and SANG/TPA-induced skin tumorigenicity. Histopathological findings suggest that papillomatous growth in AO/TPA- and SANG/TPA-treated animals were substantially protected following topical application of TOCO or NAC. Further, treatment of TOCO and NAC either alone or in combination to AO/TPA- or SANG/TPA-induced mice significantly decreased lipid peroxidation, along with significant revival in glutathione (GSH) content and activities of tyrosinase, histidase, catalase, SOD, GSH peroxidase, and GSH reductase in skin. In vitro studies showed that TOCO and/or NAC significantly decreased the AO and SANG induced cell proliferation and activation of ERK, p38, JNK MAPKs and NF-κB signaling in HaCaT cells. In summary, TOCO and NAC may be useful in preventing the tumorigenic response of AO and SANG probably by acting as scavenger of free radicals and inhibiting MAPKs and NF-κB signaling.

Modulation of multidrug resistance in cancer cells by chelidonine and Chelidonium majus alkaloids

Cancer cells often develop multidrug resistance (MDR) which is a multidimensional problem involving several mechanisms and targets. This study demonstrates that chelidonine and an alkaloid extract from Chelidonium majus, which contains protoberberine and benzo[c]phenanthridine alkaloids, has the ability to overcome MDR of different cancer cell lines through interaction with ABC-transporters, CYP3A4 and GST, by induction of apoptosis, and cytotoxic effects. Chelidonine and the alkaloid extract inhibited P-gp/MDR1 activity in a concentration-dependent manner in Caco-2 and CEM/ADR5000 and reversed their doxorubicin resistance. In addition, chelidonine and the alkaloid extract inhibited the activity of the drug modifying enzymes CYP3A4 and GST in a dose-dependent manner. The alkaloids induced apoptosis in MDR cells which was accompanied by an activation of caspase-3, -8,-6/9, and phosphatidyl serine (PS) exposure. cDNA arrays were applied to identify differentially expressed genes after treatment with chelidonine and the alkaloid extract. The expression analysis identified a common set of regulated genes related to apoptosis, cell cycle, and drug metabolism. Treatment of Caco-2 cells with 50 μg/ml alkaloid extract and 50 μM chelidonine for up to 48 h resulted in a significant decrease in mRNA levels of P-gp/MDR1, MRP1, BCRP, CYP3A4, GST, and hPXR and in a significant increase in caspase-3 and caspase-8 mRNA. Thus, chelidonine is a promising model compound for overcoming MDR and for enhancing cytotoxicity of chemotherapeutics, especially against leukaemia cells. Its efficacy needs to be confirmed in animal models.

The comet assay: assessment of in vitro and in vivo DNA damage

Rapid industrialization and pursuance of a better life have led to an increase in the amount of chemicals in the environment, which are deleterious to human health. Pesticides, automobile exhausts, and new chemical entities all add to air pollution and have an adverse effect on all living organisms including humans. Sensitive test systems are thus required for accurate hazard identification and risk assessment. The Comet assay has been used widely as a simple, rapid, and sensitive tool for assessment of DNA damage in single cells from both in vitro and in vivo sources as well as in humans. Already, the in vivo comet assay has gained importance as the preferred test for assessing DNA damage in animals for some international regulatory guidelines. The advantages of the in vivo comet assay are its ability to detect DNA damage in any tissue, despite having non-proliferating cells, and its sensitivity to detect genotoxicity. The recommendations from the international workshops held for the comet assay have resulted in establishment of guidelines. The in vitro comet assay conducted in cultured cells and cell lines can be used for screening large number of compounds and at very low concentrations. The in vitro assay has also been automated to provide a high-throughput screening method for new chemical entities, as well as environmental samples. This chapter details the in vitro comet assay using the 96-well plate and in vivo comet assay in multiple organs of the mouse.

Phenotype of hepatic xenobiotic metabolizing enzymes and CYP450 isoforms of sanguinarine treated rats: effect of P450 inducers on its toxicity

Catalytic and immunochemical activities of cytochrome P450 (CYP) isoforms were investigated in argemone alkaloid, sanguinarine (SAN) intoxicated rats, pre-treated with different CYP inducers. SAN treated control (CON) and ethanol (ET), 3- methylcholantherene (MC) or dexamethasone (DEX) pre-exposed rats, resulted in 48, 64, 47 and 33% decrease in CYP content. SAN exposure to CON, and DEX, MC or ET pre-treated animals caused a decrease (22-37%) in glutathione-S-transferase (GST) activity, however, quinone reductase (QR) activity decreased (26-45%) in the MC pre-exposed group. Similarly, western-blot analysis of hepatic CYP1A1 and CYP1A2 showed a decrease (27-37%) in MC pre-treated SAN exposed animals. Further, a decrease in mortality in the SAN+MC (25%) group compared to SAN treated animals was also observed. The results suggest that inhibition of CYP 1A1, 1A2, 2D1, 2E1, 3A1, and Phase II enzymes by SAN augments its toxicity, whereas attenuation of SAN toxicity by MC may be due to removal of parent compound/metabolites from the body.

Sanguinarine

Sanguinarine is an alkaloid found in many medicinal plants. It has diverse biological activities, including modulation of nuclear factor-kappaB and of several enzymes. It is also known to induce apoptosis, perturb microtubules, and to have antimicrobial effects. This article reviews its cardiovascular properties, including hypotensive, antiplatelet, and positive inotropic effects. Its pharmacokinetics, and toxicology, including its carcinogenic potential, are also discussed. Further pharmacological and toxicological studies with sanguinarine are needed before its therapeutic use can be considered.

Sanguinarine causes DNA damage and p53-independent cell death in human colon cancer cell lines

The benzophenanthridine alkaloid sanguinarine has antimicrobial and possibly anticancer properties but it is not clear to what extent these activities involve DNA damage. Thus, we studied its ability to cause DNA single and double strand breaks, as well as increased levels of 8-oxodeoxyguanosine, in human colon cancer cells and found DNA damage consistent with oxidation. Since the tumor suppressor p53 is frequently involved in inducing apoptosis following DNA damage we investigated the effect of sanguinarine in wild type, p53-mutant and p53-null colon cancer cell lines. We found them to be equally sensitive to this plant compound, indicating that cell death is not mediated by p53 in this case. In addition, our observation that apoptosis induced by sanguinarine is initiated very rapidly raised the question whether there is enough time for cellular signaling in response to DNA damage. Moreover, the abundance of double strand breaks is not consistent with only oxidative damage to DNA. We conclude that the majority of DNA double strand breaks in sanguinarine-treated cells are likely the result, rather than the cause, of apoptotic cell death and that apoptosis induced by sanguinarine is independent of p53 and most likely independent of DNA damage.

Preventive effects of lupeol on DMBA induced DNA alkylation damage in mouse skin

Mutations that occur through DNA strand breaks are the precursors of the variety of genetic disorders including cancer. Life style and dietary habits are considered as major determinants in causation and prevention of genetic diseases. Epidemiological and laboratory studies suggest that plant derived compounds have the potential to prevent a number of genetic diseases. Therefore, use of nutraceuticals can be an important and convenient tool for chemoprevention. Polyphenolic phytochemicals such as epigallocatechin gallate flavonoids quercetin, genistein, curcumin and resveratrol constitute a class of nutraceuticals with notable efficacy in preclinical models of carcinogenesis. Lupeol, a pentacyclic triterpene present in mango, is a biologically active compound that has been reported to possess a number of pharmacological properties in the in vivo and in vitro studies. In the present study, we investigated the effects of lupeol on 7,12-dimethylbenz[a]anthracene (DMBA), induced DNA strand breaks in mouse skin, using an alkaline unwinding assay. Increasing doses of lupeol (50-200 microg/mouse) were given topically, prior or after the single topical application of DMBA (100 microg/mouse) with the sampling time of 24, 48, 72 and 96 h, respectively. Both pre and post treatment of lupeol showed significant (p<0.001) preventive effects in DMBA induced DNA strand breaks in dose and time dependent manner. The pre-treatment of lupeol at the dose of 200 microg/mouse showed 56.05% prevention, and post-treatment at the same dose showed 43.26% prevention, at 96 h time interval, against DMBA induced DNA strand breakage. The results suggest preventive effects of lupeol on DMBA induced DNA alkylation damage in Swiss albino mice.

Adulteration of mustard cooking oil with argemone oil: do Indian food regulatory policies and antioxidant therapy both need revisitation?

Consumption of adulterated mustard oil (Brassica nigra) with argemone oil (Argemone mexicana) even for a short duration leads to a clinical condition referred as epidemic dropsy. In humans, argemone oil contained in adulterated mustard oil causes oxidative stress and death of red blood cells via met-hemoglobin formation by altering pyridine nucleotide(s) and glutathione redox potential. Argemone oil contamination poses a serious threat to human health and should be checked by appropriate regulatory measures. Antioxidant therapy provides symptomatic relief and should be seriously considered for therapeutic interventions against argemone oil toxicity.

Protective effect of bioantioxidants on argemone oil/sanguinarine alkaloid induced genotoxicity in mice

Our prior studies have shown that argemone oil (AO) and its alkaloid sanguinarine causes DNA damage in mice and Epidemic Dropsy patients. Since some of the bioantioxidants including riboflavin and alpha-tocopherol offered protection to Epidemic Dropsy patients, a combination of riboflavin and alpha-tocopherol was evaluated on AO and sanguinarine induced genotoxicity using alkaline comet assay. Single administration of combination of riboflavin (50mg/kg) and alpha-tocopherol (150mg/kg) to mice, 24h prior to or immediately after AO (2.0ml/kg) exposure showed significant decrease in tail moment (70-72%), tail length (37-44%), and tail DNA (49-53%) in bone marrow cells. Single or multiple doses of antioxidants given after 24h of AO exposure resulted in substantial (P<0.05) decrease in all the parameters of comet assay in bone marrow cells. Single dose of antioxidants given either 24h prior to or immediately after sanguinarine (21.6mg/kg) exposure caused significant decrease in tail moment (56-62%), tail length (69%) and tail DNA (34-42%) in bone marrow cells of mice. Single or multiple doses of antioxidants given after 24h of sanguinarine treated resulted in decrease in tail moment (50-71%), tail length (54-63%) and tail DNA (29-43%) in bone marrow cells. Similar protective response of combination of antioxidants was observed in blood cells of mice treated either with AO or sanguinarine alkaloid. Further, the frequency of bone marrow and blood cells in Olive tail moment category of 8 and onwards were found to be substantially reduced in antioxidants treated animals as compared to respective AO or sanguinarine exposed mice. Based on these results, it can be suggested that a combination of riboflavin and alpha-tocopherol provides protection against AO and sanguinarine induced genotoxicity.

EFFECTS OF SANGUINARINE AND CHELERYTHRINE ON THE CELL CYCLE AND APOPTOSIS

OBJECTIVES

This review summarizes the involvement of sanguinarine and chelerythrine in cell cycle regulation and cell death in various cell lines. It is focused on their potential in the treatment of cancer.

METHODS

We conducted a search of PubMed, ScienceDirect and Medline for papers on the molecular mechanisms of the biological activity of sanguinarine and chelerythrine published mainly from 1995 to 2006.

RESULTS AND CONCLUSIONS

Our analysis of the published studies suggested that these alkaloids are not only good candidates for chemotherapeutic regimens but may also contribute to the development of successful immune therapies of some carcinomas due to their apoptotic potential. However, the complete signalling cascade in which sanguinarine and chelerythrine treatment induces apoptotic cell death is not yet understood. Overall, the results of recent studies suggest that sanguinarine and chelerythrine may be useful as agents in the management of cancer.

Safety evaluation studies on argemone oil through dietary exposure for 90days in rats

Epidemic dropsy is a disease caused by the consumption of mustard oil contaminated with argemone oil (AO). During 1998 dropsy in New Delhi, which is so far the largest with more than 3000 victims and over 60 deaths, it was enquired at various scientific and regulatory meetings about the maximum tolerated dose of AO. Hence, the present study was aimed to investigate the safety levels of AO in rats. Animals were given AO in diet at a dose of 0.001%, 0.01%, 0.1%, 0.5% and 1% daily for 90 days and the two control groups received the standard diet with and without 1% mustard oil. A decrease in body weight gain (28-31%) was observed in 0.5% and 1% AO groups; while significant increases in relative lungs and liver weight was noticed in respective doses of 0.01% and 0.1% AO groups as well as in higher dosage animals. Reduction in RBC count and hemoglobin content (p<0.05) was noticed in 0.01% and 0.1% AO exposed animals. This effect was more pronounced in higher AO doses. Serum marker enzymes including alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were found to be significantly elevated in 0.01-1% AO groups. Further, a decrease in albumin/globulin ratio (42-78%) was observed in the serum of 0.01% to higher AO dose groups. The levels of serum triglycerides and VLDL cholesterol were found to be enhanced (p<0.05) in AO treated (0.01-1.0%) animals. Histopathological changes in lung were observed at 0.01% dose of AO while liver, kidney and heart produced changes at 0.1% AO and above doses. None of the parameters were found to be affected in 0.001% AO treated animals. These results suggest that the no observed adverse effect level (NOAEL) dose of AO is 0.001% in rats and considering a factor of 100 for humans for highly toxic compound, the safe limit of 0.00001% (100 ppb or 100 ng AO/g oil) AO can be implicated which shall contain only 0.55% of sanguinarine equivalent to 0.6 ng sanguinarine per gram oil. However, the minimum detectable limit of AO is 5 ppm (equivalent to 5 microg sanguinarine per gram oil) with the present existing HPLC method, thereby suggesting that mustard oil should be absolutely free from AO contamination.

Induction of P53, P21Waf1, orinithine decorboxylase activity, and DNA damage leading to cell-cycle arrest and apoptosis following topical application of repeated fish fried oil extract to mice

Repeated frying of food produces numerous carcinogens including polycyclic aromatic hydrocarbons (PAHs). Our prior studies have shown that repeated fish fried oil extract (RFFE) induces cytochrome P (CYP)-450 1A1/2 isozymes thereby causing increased generation of electrophilic reactive metabolites of PAHs and subsequent binding to DNA. In the present study, molecular events associated with DNA damage, apoptosis, and proliferation following topical exposure to RFFE have been investigated in mice. Single topical application of RFFE (500 microg) for 24-48 h caused significant DNA damage with Comet assay in terms of olive tail moment (OTM) (204-246%), tail DNA (253-293%), and tail length (172-195%). Overexpression of p53 and p21WAF1 proteins was observed in skin cells following single topical exposure of RFFE for 24-72 h, which was similar to that of benzo(a)pyrene (BP) exposure (24 h). Though RFFE and BP exposure separately, did not result in G(0)/G(1) arrest, but a significant increase in the proportion of cells in S-phase was observed. Apoptotic induction was noticed in skin cells, with maximum induction after 48 h of exposure to RFFE. Further, topical treatment of mice with RFFE (500 microg) for 6 h significantly increased orinithine decarboxylase (ODC) activity by 7.5-fold when compared to control. These results indicate that RFFE exposure caused ODC induction accompanied by increased levels of p53 and p21WAF1 proteins leading of apoptosis and delay of cells in S-phase thereby indicating the possible carcinogenic potential of RFFE.