Effect of chlorophyllin against oxidative stress in splenic lymphocytes in vitro and in vivo

Anti-Cancer Effect of Chlorophyllin-Assisted Photodynamic Therapy to Induce Apoptosis through Oxidative Stress on Human Cervical Cancer

Photodynamic therapy is an alternative approach to treating tumors that utilizes photochemical reactions between a photosensitizer and laser irradiation for the generation of reactive oxygen species. Currently, natural photosensitive compounds are being promised to replace synthetic photosensitizers used in photodynamic therapy because of their low toxicity, lesser side effects, and high solubility in water. Therefore, the present study investigated the anti-cancer efficacy of chlorophyllin-assisted photodynamic therapy on human cervical cancer by inducing apoptotic response through oxidative stress. The chlorophyllin-assisted photodynamic therapy significantly induced cytotoxicity, and the optimal conditions were determined based on the results, including laser irradiation time, laser power density, and chlorophyllin concentration. In addition, reactive oxygen species generation and Annexin V expression level were detected on the photodynamic reaction-treated HeLa cells under the optimized conditions to evaluate apoptosis using a fluorescence microscope. In the Western blotting analysis, the photodynamic therapy group showed the increased protein expression level of the cleaved caspase 8, caspase 9, Bax, and cytochrome C, and the suppressed protein expression level of Bcl-2, pro-caspase 8, and pro-caspase 9. Moreover, the proposed photodynamic therapy downregulated the phosphorylation of AKT1 in the HeLa cells. Therefore, our results suggest that the chlorophyllin-assisted photodynamic therapy has potential as an antitumor therapy for cervical cancer.

Could chlorophyllins improve the safety profile of beta-d-N4-hydroxycytidine versus N-hydroxycytidine, the active ingredient of the SARS-CoV-2 antiviral molnupiravir?

Could natural plant pigment (chlorophyll) derivatives (chlorophyllins) improve the safety of the antiviral Molnupiravir, used to treat COVID-19 disease?

Molnupiravir, a specific SARS-CoV-2 antiviral, may cause adverse genetic changes and thereby create potential host cell damage (through genotoxicity and DNA stressors). In our opinion, this side effect of treatment could be reduced if the antiviral was taken as a combined therapy with chlorophyllins. Specifically, we hypothesise that chlorophyllins might improve the overall effectiveness of molnupiravir, typically used to treat patients suffering from COVID-19. Chlorophyllins, antioxidants derived from natural plant chlorophyll, are safe, effective and non-toxic antioxidants that could combat possible genotoxic flow-on effects of molnupiravir. In addition, as they possess antiviral properties, treatment with chlorophyllins may enhance the overall antiviral effect via a mechanism different to molnupiravir.

Relationship between lifespan and somatic mutation in D. melanogaster after treatment with chlorophyllin

Sodium copper chlorophyllin (SCC) has a genetic damage inhibitory capacity due to its antioxidant action. For this reason, it was considered to investigate its role in the life span of Drosophila melanogaster and its relationship with the frequency of somatic mutation induced by gamma rays. Results indicated that SCC alone prolonged the lifespan only in females, but in combination with 20 Gy of gamma rays, the aging delay in both sexes was significant. In addition to confirming that the porphyrin reduces the frequency of mutation, the individuals with the highest mutation load are the individuals who die more quickly, and once they are eliminated, the survivor individuals treated with 20 Gy or with SCC + 20 Gy, died at the same rate. The results together indicate that SCC not only inhibits induced genetic damage, but it also has beneficial effects that probably cause an aging delay of the treated population that need to be investigated.

Light-Activated Biomedical Applications of Chlorophyll Derivatives

Tetrapyrroles are the basis of essential physiological functions in most living organisms. These compounds represent the basic scaffold of porphyrins, chlorophylls, and bacteriochlorophylls, among others. Chlorophyll derivatives, obtained by the natural or artificial degradation of chlorophylls, present unique properties, holding great potential in the scientific and medical fields. Indeed, they can act as cancer-preventing agents, antimutagens, apoptosis inducers, efficient antioxidants, as well as antimicrobial and immunomodulatory molecules. Moreover, thanks to their peculiar optical properties, they can be exploited as photosensitizers for photodynamic therapy and as vision enhancers. Most of these molecules, however, are highly hydrophobic and poorly soluble in biological fluids, and may display undesired toxicity due to accumulation in healthy tissues. The advent of nanomedicine has prompted the development of nanoparticles acting as carriers for chlorophyll derivatives, facilitating their targeted administration with demonstrated applicability in diagnosis and therapy. In this review, the chemical and physical properties of chlorophyll derivatives that justify their usage in the biomedical field, with particular regard to light-activated dynamics are described. Their role as antioxidants and photoactive agents are discussed, introducing the most recent nanomedical applications and focusing on inorganic and organic nanocarriers exploited in vitro and in vivo.

Shengxuening Extracted from Silkworm Excrement Mitigates Myelosuppression via SCF-Mediated JAK2/STAT3 Signaling

Shengxuening (SXN) is a Chinese patent medicine with main ingredients (including chlorophyll derivatives and sodium iron chlorophyllin) extracted from silkworm excrement. SXN exhibited efficacy in clinical trials of renal anemia and iron deficiency anemia; however, the specific mechanisms remain unclear. This study found that SXN increased the number of peripheral blood cells and improved the bone marrow morphology in myelosuppressed mouse model, reversed the reduction in body weight and spleen indices, and increased the serum levels of erythropoietin and granulocyte-macrophage colony-stimulating factor. Quantitative real-time PCR array and Western blot analysis showed the enhanced expression of stem cell factor (SCF), JAK2, and STAT3 in the liver. These results suggested that SXN promoted the recovery of hemopoietic function in myelosuppressed models by increasing the secretion of hematopoietic factors and activating the JAK2/STAT3 pathway. Therefore, this medicine may be applied as therapeutic pharmaceutical drug to mitigate myelosuppression.

Nano-scaled materials may induce severe neurotoxicity upon chronic exposure to brain tissues: A critical appraisal and recent updates on predisposing factors, underlying mechanism, and future prospects

Owing to their tremendous potential, the inference of nano-scaled materials has revolutionized many fields including the medicine and health, particularly for development of various types of targeted drug delivery devices for early prognosis and successful treatment of various diseases, including the brain disorders. Owing to their unique characteristic features, a variety of nanomaterials (particularly, ultra-fine particles (UFPs) have shown tremendous success in achieving the prognostic and therapeutic goals for early prognosis and treatment of various brain maladies such as Alzheimer's disease, Parkinson's disease, brain lymphomas, and other ailments. However, serious attention is needful due to innumerable after-effects of the nanomaterials. Despite their immense contribution in optimizing the prognostic and therapeutic modalities, biological interaction of nanomaterials with various body tissues may produce severe nanotoxicity of different organs including the heart, liver, kidney, lungs, immune system, gastro-intestinal system, skin as well as nervous system. However, in this review, we have primarily focused on nanomaterials-induced neurotoxicity of the brain. Following their translocation into different regions of the brain, nanomaterials may induce neurotoxicity through multiple mechanisms including the oxidative stress, DNA damage, lysosomal dysfunction, inflammatory cascade, apoptosis, genotoxicity, and ultimately necrosis of neuronal cells. Our findings indicated that rigorous toxicological evaluations must be carried out prior to clinical translation of nanomaterials-based formulations to avoid serious neurotoxic complications, which may further lead to develop various neuro-degenerative disorders.

Carotenoids and Chlorophylls as Antioxidants

Chlorophylls and carotenoids are natural pigments that are present in our daily diet, especially with the increasing tendency towards more natural and healthy behaviors among consumers. As disturbed antioxidant homeostasis capacities seem to be implicated in the progress of different pathologies, the antioxidant properties of both groups of lipophilic compounds have been studied. The objective of this review was to analyze the state-of-the-art advances in this field. We conducted a systematic bibliographic search (Web of Science™ and Scopus®), followed by a comprehensive and critical description of the results, with special emphasis on highly cited and more recently published research. In addition to an evaluative description of the methodologies, this review discussed different approaches used to obtain a physiological perspective, from in vitro studies to in vivo assays using oxidative biomarkers. From a chemical viewpoint, many studies have demonstrated how a pigment's structure influences its antioxidant response and the underlying mechanisms. The major outcome is that this knowledge is essential for interpreting new data in a metabolic networks context in the search for more direct applications to health. A promising era is coming where the term "antioxidant" is understood in terms of its broadest significance.

Sodium Copper Chlorophyllin Is Highly Effective against Enterovirus (EV) A71 Infection by Blocking Its Entry into the Host Cell

Human enteroviruses (HEVs) pose an ongoing threat to global public health. Particularly, enterovirus-A71 (EV-A71), the main pathogen causing hand-foot-and-mouth disease (HFMD), has caused ongoing outbreaks globally in recent years associated with severe neurological manifestations and several deaths. Currently, no effective antivirals are available for the prevention or treatment of EV-A71 infection. In this study, we found that sodium copper chlorophyllin (CHL), a health food additive and an over-the-counter anticancer medicine or treatment to reduce the odor of urine or feces, exhibited potent inhibitory activity against infection by divergent EV-A71 and coxsackievirus-A16 (CV-A16) isolates at a low micromolar concentration with excellent safety. The antiviral activity of each was confirmed by colorimetric viral infection and qRT-PCR assays. A series of mechanistic studies showed that CHL did not target the host cell but blocked the entry of EV-A71 and CV-A16 into the host cell at the postattachment stage. In the mouse model, CHL could significantly reduce the viral titer in the lungs and muscles. Since CHL has been used in clinics for many years with excellent safety, it has the potential to be further developed into a prophylactic or therapeutic to prevent or treat HFMD caused by EV-A71 or CV-A16 infection.

Radioprotective properties of food colorant sodium copper chlorophyllin on human peripheral blood cells in vitro

Sodium copper chlorophyllin (CHL) is a food colorant that exhibits many beneficial properties, including potential for use in radiotherapy. Nevertheless, genotoxicity studies investigating radioprotective properties against γ-radiation on human cells are rather scarce. The aim of this study was to assess the cytotoxicity, genotoxicity and induction of malondialdehyde formation on CHL pre-treated whole blood cells after an absorbed dose of 5 Gy γ-radiation. Irradiated whole blood cells pre-treated with 100, 500, and 1000 μg/mL CHL showed less DNA-strand breaks (10.92 ± 0.74%, 10.69 ± 0.68%, and 8.81 ± 0.69%, respectively) than untreated irradiated cells (12.58 ± 0.88%). At the same time, the level of malondialdehyde was lower in CHL pre-treated samples with 100, 500, and 1000 μg/mL CHL (14.11 ± 0.43, 16.35 ± 2.82, and 13.08 ± 1.03 μmol/L, respectively) compared to untreated irradiated samples (24.11 ± 0.25 μmol/L). Regarding cytotoxicity, no changes were observed in the samples tested. Another important finding is that CHL had no cyto/genotoxic properties toward human blood cells. Taken together, since CHL had no cyto/genotoxic effects and showed good radioprotective properties in human blood cells, further studies should be conducted in order to find its possible application in radiotherapy.

Chlorophyllin supplementation modulates hyperglycemia-induced oxidative stress and apoptosis in liver of streptozotocin-administered mice

Chlorophyllin is a water-soluble mixture of sodium-copper salts of chlorophyll with antioxidant and antimutagen properties. In this study, an attempt has been made to evaluate the effect of chlorophyllin on hyperglycemia-induced oxidative stress and apoptosis in liver of streptozotocin (STZ)-administered mice. In STZ-induced diabetes, two causative factors for pancreatic β-cell deaths are DNA alkylation and profound reactive oxygen species (ROS) generation. In this study, chlorophyllin treatment was found to be able to modulate oxidative stress and apoptosis in liver of diabetic mice. Diabetic mice exhibited a significant reduction of ROS, malondialdehyde (MDA), and protein carbonyl levels upon treatment with the chlorophyllin. However, antioxidant enzymes, such as copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), and catalase (CAT) showed enhanced activity as well as expression in chlorophyllin-administered diabetic mice. The hepatoprotective effect of chlorophyllin was confirmed from the decreased activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The histological and ultrastructural studies revealed the ability of chlorophyllin to restore morphological and cellular alterations as observed in STZ-induced diabetic mice. The effect of chlorophyllin on apoptosis showed the downregulation of cysteine-dependent aspartate-specific protease (caspase) 3 and caspase 9, whereas upregulation of B-cell lymphoma-2 (Bcl-2) protein, and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay demonstrated a few apoptotic cells. In conclusion, it can be stated that chlorophyllin treatment can exert hepatoprotective effect via modulating hyperglycemia-induced oxidative stress and apoptosis in STZ-administered diabetic mice. © 2018 BioFactors, 44(5):418-430, 2018.

Is Neurotoxicity of Metallic Nanoparticles the Cascades of Oxidative Stress?

With the rapid development of nanotechnology, metallic (metal or metal oxide) nanoparticles (NPs) are widely used in many fields such as cosmetics, the food and building industries, and bio-medical instruments. Widespread applications of metallic NP-based products increase the health risk associated with human exposures. Studies revealed that the brain, a critical organ that consumes substantial amounts of oxygen, is a primary target of metallic NPs once they are absorbed into the body. Oxidative stress (OS), apoptosis, and the inflammatory response are believed to be the main mechanisms underlying the neurotoxicity of metallic NPs. Other studies have disclosed that antioxidant pretreatment or co-treatment can reverse the neurotoxicity of metallic NPs by decreasing the level of reactive oxygen species, up-regulating the activities of antioxidant enzymes, decreasing the proportion of apoptotic cells, and suppressing the inflammatory response. These findings suggest that the neurotoxicity of metallic NPs might involve a cascade of events following NP-induced OS. However, additional research is needed to determine whether NP-induced OS plays a central role in the neurotoxicity of metallic NPs, to develop a comprehensive understanding of the correlations among neurotoxic mechanisms and to improve the bio-safety of metallic NP-based products.

Conifer Green Needle Complex in Patients with Precancerous Gastric Lesions: An Observational Pilot Study

Objectives. Helicobacter pylori infection is common and can lead to precancerous gastric lesions. Standard antibiotic therapy has a failure rate of more than 25% from antibiotic resistance. The primary aim of this observational pilot study was to test the feasibility of a large-scale clinical trial of Conifer Green Needle Complex (CGNC) to treat precancerous gastric lesions. Secondary aims were to investigate H. pylori infection, stomach function, and histopathology of the gastric mucosa. Methods. A tablet form of CGNC (extracted from Pinus sylvestris and Picea abies (L) Karst) was prescribed to 26 patients with precancerous gastric lesions (two tablets, 100 mg CGNC/tablet, three times per day for six months). Another 24 patients received no treatment. Results. Compared with control patients, CGNC-treated patients showed total or partial regression (using the quantitative Rome III diagnostic criteria) of dyspeptic symptoms (92.3%, p < 0.0001), eradication of H. pylori infection (57.1%, p < 0.03), a reduction in endoscopic signs of gastritis (92.3%, p < 0.001), an increase of pepsinogen-pepsin in the gastric juice (57.7%, p < 0.05), and total regression or reduction in the degree of intestinal metaplasia (46.2%, p < 0.05) and lymphoplasmacytic infiltration (53.8%, p < 0.05). Conclusions. This study justifies a randomised-controlled trial with CGNC in patients with atrophic gastritis.

Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms

Titanium dioxide nanoparticles (TiO2 NPs) possess unique characteristics and are widely used in many fields. Numerous in vivo studies, exposing experimental animals to these NPs through systematic administration, have suggested that TiO2 NPs can accumulate in the brain and induce brain dysfunction. Nevertheless, the exact mechanisms underlying the neurotoxicity of TiO2 NPs remain unclear. However, we have concluded from previous studies that these mechanisms mainly consist of oxidative stress (OS), apoptosis, inflammatory response, genotoxicity, and direct impairment of cell components. Meanwhile, other factors such as disturbed distributions of trace elements, disrupted signaling pathways, dysregulated neurotransmitters and synaptic plasticity have also been shown to contribute to neurotoxicity of TiO2 NPs. Recently, studies on autophagy and DNA methylation have shed some light on possible mechanisms of nanotoxicity. Therefore, we offer a new perspective that autophagy and DNA methylation could contribute to neurotoxicity of TiO2 NPs. Undoubtedly, more studies are needed to test this idea in the future. In short, to fully understand the health threats posed by TiO2 NPs and to improve the bio-safety of TiO2 NPs-based products, the neurotoxicity of TiO2 NPs must be investigated comprehensively through studying every possible molecular mechanism.

Amelioration of radiation-induced hematopoietic syndrome by an antioxidant chlorophyllin through increased stem cell activity and modulation of hematopoiesis

Hematopoietic stem cells and progenitor cells (HSPC) are low in abundance and exhibit high radiosensitivity and their ability to divide dramatically decreases following exposure to ionizing radiation. Our earlier studies have shown antiapoptotic, immune-stimulatory, and antioxidant effects of chlorophyllin, a constituent of the over the counter drug derifil. Here we describe the beneficial effects of chlorophyllin against radiation-induced hematopoietic syndrome. Chlorophyllin administration significantly enhanced the abundance of HSPC in vivo. It induced a transient cell cycle arrest in lineage-negative cells in the bone marrow. However, the chlorophyllin-treated mice exposed to whole body irradiation (WBI) had a significantly higher proportion of actively dividing HSPC in the bone marrow as compared to only WBI-exposed mice. It significantly increased the number of colony forming units (CFUs) by bone marrow cells in vitro and spleen CFUs in irradiated mice in vivo. Pharmacokinetic study showed that chlorophyllin had a serum half-life of 141.8 min in mice. Chlorophyllin upregulated antiapoptotic genes and antioxidant machinery via activation of prosurvival transcription factors Nrf-2 and NF-κB and increased the survival and recovery of bone marrow cells in mice exposed to WBI. Chlorophyllin stimulated granulocyte production in bone marrow and increased the abundance of peripheral blood neutrophils by enhancing serum levels of granulocyte-colony stimulation factor (GCSF). Most importantly, prophylactic treatment of mice with chlorophyllin significantly abrogated radiation-induced mortality. Chlorophyllin mitigates radiation-induced hematopoietic syndrome by increasing the abundance of hematopoietic stem cells, enhancing granulopoiesis, and stimulating prosurvival pathways in bone marrow cells and lymphocytes.

In vitro Antioxidant Activities of Sodium Zinc and Sodium Iron Chlorophyllins from Pine Needles

Chlorophyll was extracted from pine needles, and then sodium zinc chlorophyllin (SZC) and sodium iron chlorophyllin (SIC) were synthesised by saponification, purification and substitution reaction, using sodium copper chlorophyllin (SCC) as a control. Their crystalline structures were verified by atomic absorbance spectroscopy, UV-VIS spectroscopy and HPLC. Moreover, their antioxidant activities were evaluated and compared with that of ascorbic acid through four biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of β-carotene bleaching and O ^₂- scavenging activity. SZC had better antioxidant properties at a lower dosage than SIC and SCC in all assays. In the β-carotene bleaching assay, EC _⁵⁰ of SZC, SIC and SCC was 0.04, 0.38 and 0.90 mg/mL, respectively, much lower than that of ascorbic acid (4.0 mg/mL). SZC showed a better result (p<0.05) than ascorbic acid in the O ^₂- scavenging activity assay. The results obtained from reducing power determination were also excellent: the absorbance values were all about 1.0 at 0.5 mg/mL, about half of that of ascorbic acid. In the investigation of DPPH radical scavenging activity, all chlorophyllins had lower activities than ascorbic acid. These results demonstrated the potential bioactivities of chlorophyll derivatives and supported their possible role in human health protection and disease prevention.

Normalization of nano-sized TiO2-induced clastogenicity, genotoxicity and mutagenicity by chlorophyllin administration in mice brain, liver, and bone marrow cells

The intensive uses of titanium dioxide (TiO2) nanoparticles in sunscreens, toothpaste, sweats, medications, etc. making humans exposed to it daily by not little amounts and also increased its risks including genotoxicity. Thus, the present study was designed as one way to reduce nano-titanium-induced clastogenicity, genotoxicity, and mutagenicity in mice by co-administration of the free radical scavenger chlorophyllin (CHL). In addition, markers of oxidative stress were detected to shed more light on mechanism(s) underlying nano-sized TiO2 genotoxicity. Male mice were exposed to multiple injection into the abdominal cavity for five consecutive days with either CHL (40 mg/kg bw/day), or each of three dose levels of nano-sized TiO2 (500, 1000, or 2000 mg/kg bw/day) alone, or both simultaneously and sacrificed by cervical dislocation 24 h after the last treatment. After CHL co-administration, the observed dose-dependent genotoxicity of TiO2 nanoparticles indicated by the significant elevations in frequencies of both micronuclei and DNA damage induction was significantly decreased and returned to the negative control level. The observed induced mutations in p53 exons 5, 7, & 8 and 5 & 8 in the liver and brain, respectively, were declined in most cases. Moreover, CHL significantly decreased hepatic malondialdehyde level and significantly increased glutathione level and superoxide dismutase, catalase, and glutathione peroxidase activities that were significantly disrupted in animal groups treated with nano-TiO2 alone. In conclusion, the evidenced in vivo genotoxicity of nano-TiO2 in the present study was normalized after CHL co-administration which supports the previously suggested oxidative stress as the possible mechanism for titanium toxicity.

The effects of husbandry system on the grass intake and egg nutritive characteristics of laying hens

BACKGROUND

The aim of this study was to determine the effect of husbandry system and season on the grass intake and egg quality in laying hens considering that characteristics of organic eggs obtained in a system with no grass in the external area are similar conventional ones.

RESULTS

Three hundred and sixty Ancona hens were randomly assigned to three groups: a control group (C), with the hens kept in cages under standard housing conditions; the organic group (O), with the hens kept under an organic production system (4 m² per hen) and the organic-plus group (OP), with the hens maintained under organic conditions but with a larger grass paddock availability (10 m² per hen). The estimated intake of forage, carotenoids and flavonoids of the OP hens was very high as the amounts deposited in eggs, mainly in the spring season. The fatty acid composition of the yolk was significantly affected by pasture. The OP eggs showed lower concentrations of polyunsaturated fatty acids (PUFA) n-6 and a higher percentage of PUFA n-3.

CONCLUSIONS

The results showed that the grass intake was largely affected by the husbandry system and highlighted the seasonal effect of grass availability on the nutritional quality of eggs produced in organic systems.

Chlorophyll-related compounds inhibit cell adhesion and inflammation in human aortic cells

The objectives of this study were to investigate the effects of chlorophyll-related compounds (CRCs) and chlorophyll (Chl) a+b on inflammation in human aortic endothelial cells. Adhesion molecule expression and interleukin (IL)-8, nuclear factor (NF)-κB p65 protein, and NF-κB and activator protein (AP)-1 DNA binding were assessed. The effects of CRCs on inflammatory signaling pathways of signal transducers and activators of transcription 3 (STAT3) and mothers against decapentaplegic homolog 4, respectively induced by IL-6 and transforming growth factor (TGF)-β, in human aortic smooth muscle cells cultured in vitro were also investigated. HAECs were pretreated with 10 μM of CRCs, Chl a+b, and aspirin (Asp) for 18 h followed by tumor necrosis factor (TNF)-α (2 ng/mL) for 6 h, and U937 cell adhesion was determined. TNF-α-induced monocyte-endothelial cell adhesion was significantly inhibited by CRCs. Moreover, CRCs and Chl a+b significantly attenuated vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and IL-8 expressions. Treatments also significantly decreased in NF-κB expression, DNA binding, and AP-1 DNA binding by CRCs and Asp. Thus, CRCs exert anti-inflammatory effects through modulation of NF-κB and AP-1 signaling. Ten micromoles of CRCs and Asp upregulated the expression of mothers against decapentaplegic homolog 4 (Drosophila) (SMAD4) in the TGF-β receptor signaling pathway, and SMAD3/4 transcription activity was also increased. Ten micromoles of CRCs were able to potently inhibit STAT3-binding activity by repressing IL-6-induced STAT3 expression. Our results provide a potential mechanism that explains the anti-inflammatory activities of these CRCs.

Heterocyclic Aromatic Amines Heterocomplexation with Biologically Active Aromatic Compounds and Its Possible Role in Chemoprevention

Food-borne heterocyclic aromatic amines (HCAs) are known mutagens and carcinogens present especially in Western population diet, which contains large amount of meat and its products. HCAs are capable of interacting with DNA directly through the formation of covalent adducts, however this process requires biological activation in liver, mainly by cytochrome P450 enzymes. This process may produce mutations and in consequence may contribute to the development of cancer. However, there are many studies showing that several biologically active aromatic compounds (BACs) may protect against genotoxic effects of HCAs. Direct interactions and noncovalent heterocomplexes formation may be one of the most important mechanisms of such protection. This work describes several BACs present in human diet, which are capable of molecular complexes formation with HCAs and protect cells as well as whole organisms against HCAs action.

Pro-oxidants ameliorate radiation-induced apoptosis through activation of the calcium-ERK1/2-Nrf2 pathway

There are no reports describing the ability of pro-oxidants to protect against radiation-induced apoptosis. Activation of the redox-sensitive transcription factor Nrf2 by low levels of ROS is known to protect against oxidative stress-induced cell death. In this study, hydrogen peroxide, diethylmaleate, and 1,4-naphthoquinone (NQ) exhibited complete protection against radiation-induced cell death in lymphocytes as estimated by propidium iodide staining. Radioprotection by NQ was demonstrated by inhibition of caspase activation, decrease in cell size, DNA fragmentation, nuclear blebbing, and clonogenic assay. Interestingly, NQ offered protection to lymphocytes even when added to cells postirradiation. NQ increased intracellular ROS levels and decreased GSH levels. NQ activated Nrf2 and increased the expression of the cytoprotective gene heme oxygenase-1 in lymphocytes. NQ increased ERK phosphorylation, which is upstream of Nrf2, and this ERK activation was through increased intracellular calcium levels. Administration of NQ to mice offered protection against whole-body irradiation (WBI)-induced apoptosis in splenic lymphocytes and loss of viability of spleen and bone marrow cells. It restored WBI-mediated changes in hematological parameters and functional responses of lymphocytes. Importantly, NQ rescued mice against WBI-induced mortality. These results demonstrated that a pro-oxidant such as NQ can protect against radiation-induced apoptosis by activation of multiple prosurvival mechanisms including activation of the calcium-ERK1/2-Nrf2 pathway.

Inhibition of fried meat-induced colorectal DNA damage and altered systemic genotoxicity in humans by crucifera, chlorophyllin, and yogurt

Dietary exposures implicated as reducing or causing risk for colorectal cancer may reduce or cause DNA damage in colon tissue; however, no one has assessed this hypothesis directly in humans. Thus, we enrolled 16 healthy volunteers in a 4-week controlled feeding study where 8 subjects were randomly assigned to dietary regimens containing meat cooked at either low (100°C) or high temperature (250°C), each for 2 weeks in a crossover design. The other 8 subjects were randomly assigned to dietary regimens containing the high-temperature meat diet alone or in combination with 3 putative mutagen inhibitors: cruciferous vegetables, yogurt, and chlorophyllin tablets, also in a crossover design. Subjects were nonsmokers, at least 18 years old, and not currently taking prescription drugs or antibiotics. We used the Salmonella assay to analyze the meat, urine, and feces for mutagenicity, and the comet assay to analyze rectal biopsies and peripheral blood lymphocytes for DNA damage. Low-temperature meat had undetectable levels of heterocyclic amines (HCAs) and was not mutagenic, whereas high-temperature meat had high HCA levels and was highly mutagenic. The high-temperature meat diet increased the mutagenicity of hydrolyzed urine and feces compared to the low-temperature meat diet. The mutagenicity of hydrolyzed urine was increased nearly twofold by the inhibitor diet, indicating that the inhibitors enhanced conjugation. Inhibitors decreased significantly the mutagenicity of un-hydrolyzed and hydrolyzed feces. The diets did not alter the levels of DNA damage in non-target white blood cells, but the inhibitor diet decreased nearly twofold the DNA damage in target colorectal cells. To our knowledge, this is the first demonstration that dietary factors can reduce DNA damage in the target tissue of fried-meat associated carcinogenesis.

Trial Registration

ClinicalTrials.gov NCT00340743.

Protection of DNA and membrane from γ-radiation induced damage by the extract of Acorus calamus Linn.: An in vitro study

Acorus calamus, an ethnomedicinally important plant, was investigated for its protecting activity against radiation induced DNA and membrane damage. The in vitro free radical scavenging activity of the extract (water:ethanol, 1:1) of A. calamus was studied by parameters viz DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical scavenging activity, hydroxyl radical scavenging activity, and superoxide radical scavenging activity. Membrane damage due to radiation exposure was measured as the peroxidation of lipids in terms of thiobarbituric acid reacting substance (TBARS). The in vitro DNA damage was monitored by assessing the radiation induced relaxation of supercoiled plasmid DNA (pBR322). Damage to cellular DNA induced by γ-radiation (6Gy) was monitored by alkaline single cell gel electrophoresis or comet assay in murine cells and human peripheral blood leukocytes. Enhancement of DNA repair mechanism was also monitored. The extract effectively scavenged free radicals in a concentration dependent manner. Presence of A. calamus extract during irradiation prevented peroxidation of membrane lipids in mouse liver homogenate. It helped to reduce the disappearance of the covalently closed circular (ccc) form of plasmid DNA following exposure to γ-radiation. Also the A. calamus extract effectively protected DNA from radiation induced strand breaks and enhanced the DNA repair process. Hence A. calamus extract can be used as a good source of natural radioprotecting agent.

CYP1A1 and CYP1B1 gene expression and DNA adduct formation in normal human mammary epithelial cells exposed to benzo[a]pyrene in the absence or presence of chlorophyllin

Benzo[a]pyrene (BP) is a potent pro-carcinogen and ubiquitous environmental pollutant. Here, we examined the induction and modulation of CYP1A1 and CYP1B1 and 10-(deoxyguanosin-N(2)-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPdG) adduct formation in DNA from 20 primary normal human mammary epithelial cell (NHMEC) strains exposed to BP (4muM) in the absence or presence of chlorophyllin (5muM). Real-time polymerase chain reaction (RT-PCR) analysis revealed strong induction of both CYP1A1 and CYP1B1 by BP, with high levels of inter-individual variability. Variable BPdG formation was found in all strains by r7, t8-dihydroxy-t-9, 10 epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)-DNA chemiluminescence assay (CIA). Chlorophyllin mitigated BP-induced CYP1A1 and CYP1B1 gene expression in all 20 strains when administered with BP. Chlorophyllin, administered prior to BP-exposure, mitigated CYP1A1 expression in 18/20 NHMEC strains (p<0.005) and CYP1B1 expression in 17/20 NHMEC strains (p<0.005). Maximum percent reductions of CYP1A1 and CYP1B1 gene expression and BPdG adduct formation were observed when cells were pre-dosed with chlorophyllin followed by administration of the carcinogen with chlorophyllin (p<0.005 for CYP1A1 and CYP1B1 expression and p<0.0005 for BPdG adducts). Therefore, chlorophyllin is likely to be a good chemoprotective agent for a large proportion of the human population.

Use of conventional and -omics based methods for health claims of dietary antioxidants: a critical overview

This article describes the principles and limitations of methods used to investigate reactive oxygen species (ROS) protective properties of dietary constituents and is aimed at providing a better understanding of the requirements for science based health claims of antioxidant (AO) effects of foods. A number of currently used biochemical measurements aimed of determining the total antioxidant capacity and oxidised lipids and proteins are carried out under unphysiological conditions and are prone to artefact formation. Probably the most reliable approaches are measurements of isoprostanes as a parameter of lipid peroxidation and determination of oxidative DNA damage. Also the design of the experimental models has a strong impact on the reliability of AO studies: the common strategy is the identification of AO by in vitro screening with cell lines. This approach is based on the assumption that protection towards ROS is due to scavenging, but recent findings indicate that activation of transcription factors which regulate genes involved in antioxidant defence plays a key role in the mode of action of AO. These processes are not adequately represented in cell lines. Another shortcoming of in vitro experiments is that AO are metabolised in vivo and that most cell lines are lacking enzymes which catalyse these reactions. Compounds with large molecular configurations (chlorophylls, anthocyans and polyphenolics) are potent AO in vitro, but weak or no effects were observed in animal/human studies with realistic doses as they are poorly absorbed. The development of -omics approaches will improve the scientific basis for health claims. The evaluation of results from microarray and proteomics studies shows that it is not possible to establish a general signature of alterations of transcription and protein patterns by AO. However, it was shown that alterations of gene expression and protein levels caused by experimentally induced oxidative stress and ROS related diseases can be normalised by dietary AO.

Transcriptional profiles of benzo(a)pyrene exposure in normal human mammary epithelial cells in the absence or presence of chlorophyllin

Benzo(a)pyrene (BP) exposure causes alterations in gene expression in normal human mammary epithelial cells (NHMECs). This study used Affymetrix Hu-Gene133A arrays, with 14,500 genes represented, to evaluate modulation of BP-induced gene expression by chlorophyllin in six NHMEC strains derived from different donors. A major goal was to seek potential biomarkers of carcinogen exposure and how they behave in the presence of a chemopreventive agent. NHMECs (passage 6 and 70% confluence) were exposed for 24h to either vehicle control, or BP, or chlorophyllin followed by BP and chlorophyllin together. BP exposure resulted in approximately 3-fold altered expression of 49 genes in at least one of the six NHMEC strains. When cells were exposed to chlorophyllin pre-treatment followed by BP plus chlorophyllin, expression of 125 genes was similarly altered. Genes in the functional categories of xenobiotic metabolism, cell signaling, cell motility, cell proliferation, cellular transcription, metabolism, cell cycle control, apoptosis and DNA repair were identified. Only CYP1B1 and ALDH1A3 were consistently up-regulated by approximately 3-fold in most of the cell strains (at least 4) when exposed to BP. Cluster analysis identified a suite of 13 genes induced by BP where induction was mitigated in the presence of chlorophyllin. Additionally, cluster analysis identified a suite of 16 genes down-regulated by BP where induction was partially restored in the presence of chlorophyllin.

Attenuation of acridine mutagen ICR-191--DNA interactions and DNA damage by the mutagen interceptor chlorophyllin

We have investigated the ability of chlorophyllin (CHL) to interact with acridine mutagen ICR-191 (2-methoxy-6-chloro-9-(3-(2-chloroethyl)aminopropylamino)acridine) and also its ability to decrease binding of ICR-191 to DNA in a simple three-component competition system: CHL-ICR-DNA. Our data indicate a strong association of ICR-191 with CHL, stronger even than the association of ICR-191 with DNA. Calculations based on the measured affinity data show that a two- to three-fold excess of CHL reduces by about two-fold the concentration of the mutagen-DNA complex. We also exposed human leukemic HL-60 cells to ICR-191 in the absence and presence of CHL and measured the mutagen-induced DNA damage. The extent of DNA damage was assessed by analysis of histone H2AX phosphorylation. While ICR-191 induced significant increase in expression of phosphorylated H2AX (gammaH2AX), particularly in DNA replicating cells, this increase was totally abolished in the cells treated with ICR-191 in the presence of CHL.

Delayed activation of PKCdelta and NFkappaB and higher radioprotection in splenic lymphocytes by copper (II)-Curcumin (1:1) complex as compared to curcumin

A mononuclear 1:1 copper complex of curcumin had been found to be superior to curcumin in its anti-oxidant properties. This paper describes the radio-protective effects of the complex in splenic lymphocytes from swiss mice. The complex was found to be very effective in protecting the cells against radiation-induced suppression of glutathione peroxidase, catalase and superoxide dismutase (SOD) activities. Both curcumin and the complex protected radiation-induced protein carbonylation and lipid peroxidation in lymphocytes with the complex showing better protection than curcumin. It also showed better overall protection by decreasing the radiation-induced apoptosis. The kinetics of activation of PKCdelta and NFkappaB after irradiation in presence or absence of these compounds was looked at to identify the molecular mechanism involved. The modulation of irradiation-induced activation of PKCdelta and NFkappaB by curcumin and the complex was found different at later time periods although the initial response was similar. The early responses could be mere stress responses and the activation of crucial signaling factors at later time periods may be the determinants of the fate of the cell. In this study this delayed effect was observed in case of complex but not in case of curcumin. The delayed effect of the complex along with the fact that it is a better free radical scavenger must be the reason for its better efficacy. The complex was also found to be less cytotoxic then curcumin at similar concentration.

3,3′-Diselenodipropionic Acid, an Efficient Peroxyl Radical Scavenger and a GPx Mimic, Protects Erythrocytes (RBCs) from AAPH-Induced Hemolysis

3,3'-diselenodipropionic acid (DSePA), a derivative of selenocystine, has been synthesized and examined for antioxidant activity, glutathione peroxidase (GPx) activity, and cytotoxicity. The effect of DSePA on membrane lipid peroxidation, release of hemoglobin, and intracellular K+ ion as a consequence of erythrocyte (red blood cells or RBCs) oxidation by free radicals generated by 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH) were used to evaluate the antioxidant ability. Lipid peroxidation, hemolysis, and K+ ion loss in RBCs were assessed, respectively, by formation of thiobarbituric acid reactive substances (TBARS), absorbance of hemoglobin at 532 nm and flame photometry. The IC50 values for lipid peroxidation, hemolysis, and K+ ion leakage were 45+/-5, 20+/-2, and 75+/-8 microM, respectively. DSePA treatment prevented the depletion of glutathione (GSH) levels in RBCs from free-radical-induced stress. DSePA is a good peroxyl radical scavenger and the bimolecular rate constant for the reaction of DSePA with a model peroxyl radical, trichloromethyl peroxyl radical (CCl 3O2*), was determined to be 2.7x10(8) M(-1) s(-1) using a pulse radiolysis technique. DSePA shows GPx activity with higher substrate specificity towards peroxides than thiols. The cytotoxicity of DSePA was studied in lymphocytes and EL4 tumor cells and the results showed that DSePA is nontoxic to these cells at the concentrations employed. These results when compared with two well-known selenium compounds, sodium selenite and ebselen, indicated that DSePA, although it shows lesser GPx activity, has higher free radical scavenging ability and lesser toxicity.

Role of pro-oxidants and antioxidants in the anti-inflammatory and apoptotic effects of curcumin (diferuloylmethane)

Extensive research within the past half-century has indicated that curcumin (diferuloylmethane), a yellow pigment in curry powder, exhibits antioxidant, anti-inflammatory, and proapoptotic activities. We investigated whether the anti-inflammatory and proapoptotic activities assigned to curcumin are mediated through its prooxidant/antioxidant mechanism. We found that TNF-mediated NF-kappaB activation was inhibited by curcumin; and glutathione reversed the inhibition. Similarly, suppression of TNF-induced AKT activation by curcumin was also abrogated by glutathione. The reducing agent also counteracted the inhibitory effects of curcumin on TNF-induced NF-kappaB-regulated antiapoptotic (Bcl-2, Bcl-xL, IAP1), proliferative (cyclin D1), and proinflammatory (COX-2, iNOS, and MMP-9) gene products. The suppression of TNF-induced AP-1 activation by curcumin was also reversed by glutathione. Also, the direct proapoptotic effects of curcumin were inhibited by glutathione and potentiated by depletion of intracellular glutathione by buthionine sulfoximine. Moreover, curcumin induced the production of reactive oxygen species and modulated intracellular GSH levels. Quenchers of hydroxyl radicals, however, were ineffective in inhibiting curcumin-mediated NF-kappaB suppression. Further, N-acetylcysteine partially reversed the effect of curcumin. Based on these results we conclude that curcumin mediates its apoptotic and anti-inflammatory activities through modulation of the redox status of the cell.

Curcumin, demethoxycurcumin, bisdemethoxycurcumin, tetrahydrocurcumin and turmerones differentially regulate anti-inflammatory and anti-proliferative responses through a ROS-independent mechanism

Curcumin, a component of turmeric (Curcuma longa), has been shown to exhibit chemopreventive activity. Whether analogs of curcumin (Cur), such as demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), tetrahydrocurcumin (THC) and turmerones, modulate inflammatory signaling and cell proliferation signaling to same extent as curcumin was investigated. The results indicate that the relative potency for suppression of tumor necrosis factor (TNF)-induced nuclear factor-kappaB (NF-kappaB) activation was Cur > DMC > BDMC; thus suggesting the critical role of methoxy groups on the phenyl ring. THC, which lacks the conjugated bonds in the central seven-carbon chain, was completely inactive for suppression of the transcription factor. Turmerones also failed to inhibit TNF-induced NF-kappaB activation. The suppression of NF-kappaB activity correlated with inhibition of NF-kappaB reporter activity and with down-regulation of cyclooxygenase-2, cyclin D1 and vascular endothelial growth factor, all regulated by NF-kappaB. In contrast to NF-kappaB activity, the suppression of proliferation of various tumor cell lines by Cur, DMC and BDMC was found to be comparable; indicating the methoxy groups play minimum role in the growth-modulatory effects of curcumin. THC and turmerones were also found to be active in suppression of cell growth but to a much lesser extent than curcumin, DMC and BDMC. Whether suppression of NF-kappaB or cell proliferation, no relationship of any of the curcuminoid was found with reactive oxygen species (ROS) production. Overall, our results demonstrated that different analogs of curcumin present in turmeric exhibit variable anti-inflammatory and anti-proliferative activities, which do not correlate with their ability to modulate the ROS status.

Antiapoptotic and immunomodulatory effects of chlorophyllin

Chlorophyllin (CHL) was earlier shown to reduce the level of intracellular ROS and apoptosis induced by ionizing radiation and 2,2'-azobis(2-propionimidinedihydrochloride) (AAPH). In the present studies, the effect of CHL on radiation-induced immunosuppression and modulation of immune responses in mice was examined. Chlorophyllin inhibited the in vitro lymphocyte proliferation induced by concanavalin A (Con A) in a dose dependent manner at doses>or=50 microM. At lower doses (10 microM) CHL significantly inhibited activation induced cell death (AICD) in Con A stimulated spleen cells. Spleen cells obtained from CHL treated mice showed an inhibition of response to Con A depending on dose of CHL and the time after its administration. Spleen cells obtained from CHL treated mice (24 h) showed lower inhibition of response to Con A following in vitro (5 Gy) as well as whole body irradiation (2 Gy). The expression of antiapoptotic genes bcl-2 and bcl-xL was up-regulated in these cells. Chlorophyllin treatment of mice led to splenomegaly and increase in the number of peritoneal exudate cells (PEC). The numbers of T cells, B cells and macrophages in the spleen were also increased. Increased phagocytic activity was seen in PEC obtained from CHL treated mice. Most importantly, CHL administration to mice immunized with sheep red blood cells (SRBC) augmented both humoral and cell-mediated immune responses.

Chlorophyllin suppresses interleukin-1 beta expression in lipopolysaccharide-activated RAW 264.7 cells

Our previous findings demonstrated that chlorophyllin (CHL) inhibits inducible nitric oxide gene expression in macrophages. In the present study, we show that CHL inhibited IL-1beta production and its mRNA expression in a lipopolysaccharide (LPS)-stimulated murine macrophage cell-line, RAW 264.7. The inhibitory effect of CHL on IL-1beta gene expression was further supported by an in vitro transfection assay using a pIL-1(870 bp)-CAT construct, where CHL inhibited the activation of the IL-1beta promoter. Furthermore, CHL attenuated the activation of NF-kappaB, NF-IL6 and AP-1, which are known to be responsible for IL-1beta gene expression, as determined by an electrophoretic mobility shift assay and an in vitro transfection assay using p(NF-kappaB)3-CAT, p(NF-IL6)3-CAT, and p(AP-1)3-CAT, respectively. However, it was evident that the inhibitory activity of CHL on IL-1beta expression in the LPS-stimulated macrophages was independent of CRE/ATF. The immunoblot experiment demonstrated that CHL also caused a substantial decrease in the phosphorylation of p38 MAP kinase in LPS-stimulated RAW 264.7. These results suggest that CHL inhibits IL-1beta production in macrophages stimulated with LPS at transcriptional level by blocking the phosphorylation of p38 and by suppressing the activation of transcription factors, NF-kappaB, NF-IL6, and AP-1.

Chlorophyllin attenuates IFN-γ expression in lipopolysaccharide-stimulated murine splenic mononuclear cells via suppressing IL-12 production

Chlorophyllin (CHL) is a chlorophyll derivative with anticarcinogen and antioxidant activities. Despite clinical importance of CHL as a potential therapeutics for treating cancer patients, little is known about the immunological properties of CHL. In the present study, we investigated the effect of CHL on the activation of murine splenocytes stimulated with lipopolysaccharide (LPS). RT-PCR analysis showed that LPS-activated IFN-gamma expression gradually declined by CHL treatment in a dose dependent manner while mRNA production of TNF-alpha, IL-2, and FasL was not changed. CHL also suppressed IL-12 production (p70, a heterodimer of p40 and p35) and the mRNA expression of IL-12 p40 and IL-12 receptors (both IL-12Rbeta1 and IL-12Rbeta2), which are involved in the induction of IFN-gamma expression. Furthermore, an electrophoretic mobility shift assay showed that CHL inhibited DNA binding activity of NF-kappaB, STAT-3, and STAT-4 to their cognate DNA recognition motifs, all of which contribute to the IL-12-induced IFN-gamma transcription. Exogenous addition of recombinant IL-12 abrogated the inhibitory effect of CHL on IFN-gamma and its mRNA expression in LPS-activated splenocytes. Collectively, these results show that CHL inhibits IFN-gamma production by LPS-stimulated splenic mononuclear cells due to down-regulation of IL-12 production.

Radioprotective effect of sesamol on γ-radiation induced DNA damage, lipid peroxidation and antioxidants levels in cultured human lymphocytes

Sesamol pretreated (1, 5 and 10 microg/ml) lymphocytes were exposed to different doses of gamma-radiation, i.e., 1, 2 and 4 Gray (Gy) and the cellular changes were estimated by using cytokinesis blocked micronucleus assay (MN), dicentric aberration (DC), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Radiation significantly increased MN, DC frequencies, TBARS levels and decreased GSH and antioxidant enzyme levels in a dose dependent manner. The highest damage to lymphocytes was observed at 4 Gy irradiation. On the other hand, sesamol pretreatment significantly decreased MN, DC frequencies, TBARS levels and increased GSH levels and SOD, CAT and GPx activities in a concentration dependent manner. At 1 Gy irradiation all concentrations of sesamol (1, 5 and 10 microg/ml) significantly protects the lymphocytes from radiation damage. At 2 Gy irradiation 5 and 10 microg/ml of sesamol shows significant radioprotection. Since the highest damage was observed at 4 Gy irradiation both 1 and 5 microg/ml of sesamol pretreatment were not sufficient to protect the lymphocytes from radiation damage but 10 microg/ml of sesamol significantly (p<0.05) protects the lymphocytes from radiation effect. Thus, sesamol pretreatment gives significant protection to cultured human lymphocytes against gamma-radiation induced cellular damage. The possible mechanism involved in the radioprotective influence of sesamol is discussed.