Antimutagens and anticarcinogens in foods

Characterization of Flavonoids and Transcripts Involved in Their Biosynthesis in Different Organs of Cissus rotundifolia Lam

Cissus rotundifolia Lam. is used as a medicinal herb and vegetable. Flavonoids are the major components for the therapeutic effects. However, flavonoids constituents and expression profiles of related genes in C. rotundifolia organs are unknown. Colorimetric assay showed the highest flavonoid concentration in roots compared to the stem and leaf. Widely target-based metabolome analysis allowed tentative identification of 199 compounds in three organs. Flavonols and flavones were the dominant flavonoids subclasses. Among the metabolites, 171 were common in the three organs. Unique accumulation profile was observed in the root while the stem and leaf exhibited relatively similar patterns. In the root, six unique compounds (jaceosidin, licoagrochalcone D, 8-prenylkaempferol, hesperetin 7-O-(6″malonyl) glucoside, aureusidin, apigenin-4′-O-rhamnoside) that are used for medicinal purposes were detected. In total, 18,427 expressed genes were identified from transcriptome of the three organs covering about 60% of annotated genes in C. rotundifolia genome. Fourteen gene families, including 52 members involved in the main pathway of flavonoids biosynthesis, were identified. Their expression could be found in at least one organ. Most of the genes were highly expressed in roots compared to other organs, coinciding with the metabolites profile. The findings provide fundamental data for exploration of metabolites biosynthesis in C. rotundifolia and diversification of parts used for medicinal purposes.

Resveratrol impacts in oxidative stress in liver during Trypanosoma cruzi infection

Trypanosoma cruzi is the causative agent of Chagas disease, infecting the heart, intestines and liver tissues. There is growing evidence that oxidative stress, defined as a persistent imbalance between highly oxidative compounds and antioxidant defenses, is a marker of tissue inflammation; it is related to immune responses such as damage, as well as to strand breaks in DNA contributing to disease progression. Antioxidant agents help mitigate the damage caused by inflammation, preventing or slowing damage to cells caused by free radicals. In this sense, resveratrol (RSV) is an important polyphenol that demonstrates antioxidant effects. It reverses damage caused by several infectious diseases. The aim of the present study was to determine whether treatment with RSV would prevent or minimize oxidative damage caused by T. cruzi. The animals were divided into four groups (n = 5): A) control; B) control + RSV; C) infected and D) infected + RSV. The infected groups received 1 x 10⁴ Y strain trypomastigotes via intraperitoneal injection; after confirmation of infection, the mice received RSV 100 mg/kg for seven days orally. On the 8th day post-infection, we collected liver tissue for analysis of oxidant/antioxidant status: superoxide dismutase (SOD), catalase (CAT), and glutathione s-transferase (GST) activities, as well as reactive oxygen species (ROS), non-protein thiols (NPSH), thiols, carbonyl protein, thiobarbituric acid reactive substance (TBARS), and finally, the nitrite/nitrate ratio (NOx) levels were determined. The administration of RSV did not exert direct effect on parasitemia. The infection produced high levels of TBARS, NOx, and ROS levels in liver tissue, suggesting cellular injury with production of free radicals in animals infected by T. cruzi. RSV positively modulated SOD and aumenting GST activities enzymes in infected animals. Protein thiols levels in infected animals were lower than those of control. Taken together, the data suggest T. cruzi causes hepatic oxidative stress, and RSV 100 mg/kg for seven days it's dosen't seem minimized these negative effects in the acute phase of disease.

Dietary Factors and Tinnitus among Adolescents

The number of people suffering from constant tinnitus is ever-increasing and has spread to all age groups, including adolescents. The etiology of tinnitus is multifactorial, but dietary factors have been rarely investigated. The purpose of this study is to examine the relationship between dietary factors and constant tinnitus among adolescents from an urban environment. A population-oriented cross-sectional study was carried out during the 2019/2020 school year in 12 Belgrade secondary schools. There were 1287 school children aged from 15 to 19 years who participated in the study. There were 1003 respondents who completed a questionnaire on tinnitus (response rate 77.9%; 31% male). We used the standardized Tinnitus Screener questionnaire and a food frequency questionnaire specially designed for this study and adapted to Serbian adolescents. A logistic regression analysis revealed a strong negative correlation between fresh vegetables and fruits and tinnitus presence. On the other hand, the risk of constant tinnitus increased with the increased intake of white bread, carbonated beverages, and fast food. In conclusion, we show that fresh fruit and vegetable intakes may be negatively related to tinnitus frequency, while sweetened sodas, fast food, and white bread may raise the odds for tinnitus.

Extraction, characterization and biological activity of citrus flavonoids

Citrus is one of the largest and most popular fruit crops commercially grown across the globe. It is not only important in terms of economy but is also popular for its nutritional benefits to human and farm animals. Citrus is available in several varieties, all with attractive colors. It is consumed either fresh or in processed form. After processing, approximately 50% of the fruit remains unconsumed and discarded as waste. The latter includes fruit pith residue, peels and seeds. Direct disposal of these wastes to the environment causes serious problems as these contain bioactive compounds. Release of these bioactive compounds to the open landfills cause bad odor and spread of diseases, and disposal to water bodies or seepage to the underground water table deteriorates water quality and harms aquatic life. In this regard, a number of research are being focused on the development of better reuse methods to obtain value-added phytochemicals as well as for safe disposal. The important phytochemicals obtained from citrus include essential oils, flavonoids, citric acid, pectin, etc., which have now become popular topics in industrial research, food and synthetic chemistry. The present article reviews recent advances in exploring the effects of flavonoids obtained from citrus wastes, the extraction procedure and their usage in view of various health benefits.

Effect of antioxidant supplementation on the auditory threshold in sensorineural hearing loss: a meta-analysis

INTRODUCTION

Hearing loss is conceptualized as any impairment of the ability to hear and/or detect speech or environment sounds, regardless of cause, type, or degree. It may occur at different stages of life; during pregnancy or childbirth, in childhood, adulthood or old age. It should be noted that aging is the most common cause of sensorineural hearing loss followed by noise-induced hearing loss, and both are closely related to the formation of reactive oxygen species. Dietary antioxidant supplementation has been employed as a therapeutic strategy to prevent and/or delay the risks of major human diseases.

OBJECTIVE

To assess randomized clinical trials to determine the effect of antioxidant supplementation on the auditory thresholds in patients of different age groups with sensorineural hearing loss.

METHODS

This systematic review consisted of a search in the following databases: MEDLINE, CENTRAL, ScienceDirect, Scopus, Web of Science, LILACS, SciELO and ClinicalTrials.gov. Additionally, the gray literature was also searched. The search strategy included terms related to the intervention (antioxidant supplementation), primary outcome (sensorineural hearing loss), as well as terms related to randomized clinical trials to improve search sensitivity.

RESULTS

Based on 977 potentially relevant records identified through the search in the databases, ten full-text publications were retrieved for further evaluation. The increase in threshold at the 4kHz frequency was statistically higher in the control group (1.89 [1.01-2.78], p<0.0001) when compared to the NAC group and the ginseng group, whereas at 6kHz, the threshold increase was higher in the control group (1.42 [-1.14-3.97], p=0.28), but no statistically significant differences were found between groups.

CONCLUSION

Ginseng was the antioxidant agent that showed the best effect in preventing auditory threshold worsening at the frequency of 4kHz, but not at 6kHz in patients with sensorineural hearing loss caused by exposure to high sound pressure levels. There was no improvement in the thresholds with vitamin E supplementation.

Anti-cancer activity of myricetin against human papillary thyroid cancer cells involves mitochondrial dysfunction-mediated apoptosis

Thyroid cancer is the most common endocrine malignancy and can range in severity from relatively slow-growing occult differentiated thyroid cancer to uniformly aggressive and fatal anaplastic thyroid cancer. A subset of patients with papillary thyroid cancer present with aggressive disease that is refractory to conventional treatment. Myricetin is a flavonol compound found in a variety of berries as well as walnuts and herbs. Previous studies have demonstrated that myricetin exhibits anti-cancer activity against several tumor types. However, an anti-cancer effect of myricetin against human papillary thyroid cancer (HPTC) cells has not been established. The present investigation was undertaken to gain insights into the molecular mechanism of the anti-cancer activity of myricetin against HPTC cells. We examined the cytotoxicity, DNA damaging, and cell cycle arresting activities of myricetin using SNU-790 HPTC cells. We found that myricetin exhibited cytotoxicity and induced DNA condensation in SNU-790 HPTC cells in a dose-dependent manner. Moreover, myricetin up-regulated the activation of caspase cascades and the Bax:Bcl-2 expression ratio. In addition, myricetin induced the release of apoptosis-inducing factor (AIF) and altered the mitochondrial membrane potential. Our results suggest that myricetin induces the death of SNU-790 HPTC cells and thus may prove useful in the development of therapeutic agents for human thyroid cancers.

Protective effect of saffron (Crocus sativus L.) aqueous extract against genetic damage induced by anti-tumor agents in mice

The genotoxic potential of anti-tumor drugs limits their efficacy in the treatment of cancers. Since ancient times, saffron (dried stigmas of Crocus sativus L.) has been used as a spice and medicinal herb. Saffron is a rich source of carotenoids and is known for its anti-cancer and antitumor properties. The present study was designed to ascertain the chemoprotective potential of saffron against the genotoxicity of three well-known anti-tumor drugs-cisplatin (CIS), cyclophosphamide (CPH) and mitomycin C (MMC)-using comet assay. Three doses of saffron (20, 40 and 80 mg/kg b.w.) were orally administered to mice for five consecutive days prior to the administration of anti-tumor drugs under investigation. Pre-treatment with saffron significantly inhibited anti-tumor drugs induced cellular DNA damage (strand breaks) as revealed by decreased comet tail length, tail moment and percent DNA in the tail. These findings, together with our previous results, suggest a potential role for saffron as an anti-genotoxic, anti-oxidant and chemopreventive agent and could be used as an adjuvant in chemotherapeutic applications.

Exploration of natural product ingredients as inhibitors of human HMG-CoA reductase through structure-based virtual screening

Cholesterol plays an important role in living cells. However, a very high level of cholesterol may lead to atherosclerosis. HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase is the key enzyme in the cholesterol biosynthesis pathway, and the statin-like drugs are inhibitors of human HMG-CoA reductase (hHMGR). The present study aimed to virtually screen for potential hHMGR inhibitors from natural product to discover hypolipidemic drug candidates with fewer side effects and lesser toxicities. We used the 3D structure 1HWK from the PDB (Protein Data Bank) database of hHMGR as the target to screen for the strongly bound compounds from the traditional Chinese medicine database. Many interesting molecules including polyphenolic compounds, polisubstituted heterocyclics, and linear lipophilic alcohols were identified and their ADMET (absorption, disrtibution, metabolism, excretion, toxicity) properties were predicted. Finally, four compounds were obtained for the in vitro validation experiments. The results indicated that curcumin and salvianolic acid C can effectively inhibit hHMGR, with IC50 (half maximal inhibitory concentration) values of 4.3 µM and 8 µM, respectively. The present study also demonstrated the feasibility of discovering new drug candidates through structure-based virtual screening.

Protective effect of guabiju (Myrcianthes pungens (O. Berg) D. Legrand) and red guava (Psidium cattleyanum Sabine) against cisplatin-induced hypercholesterolemia in rats

The present study was the first to examine the protective effect and antioxidant potential of two fruits native to the south of Brazil, namely guabiju (Myrcianthes pungens (O. Berg) D. Legrand) and red guava (Psidium cattleyanumSabine), with respect to reducing the effects of cisplatin-induced hypercholesterolemia in male Wistarrats. The cisplatin-treated animals showed high glucose, LDL cholesterol, oxidized LDL cholesterol and total cholesterol levels. These native fruits reversed the increase in these parameters. The fat levels in the liver improved with supplementation with the fruits, and there were no differences in the thiobarbituric acid reactive substances (TBARS), creatinine, urea or HDL cholesterol levels, nor in the weight of the organs analyzed, indicating that the dose used did not affect these markers.

Radiation-modifying abilities of Nigella sativa and thymoquinone on radiation-induced nitrosative stress in the brain tissue

To investigate Nigella sativa oil (NSO) and Thymoquinone (TQ) for their antioxidant effects on the brain tissue of rats exposed to ionizing radiation. Fifty-four male albino Wistar rats, divided into six groups, were designed as group I (normal control group) did not receive NSO, TQ or irradiation; group II (control group of TQ) received dimethyl sulfoxide and sham irradiation; group III (control group of NSO) received saline and sham irradiation; group IV (irradiation plus NSO group) received both 5 Gray of gamma irradiation to total cranium and NSO; group V (irradiation plus TQ group) received both irradiation and TQ; group VI (irradiation alone group) received irradiation plus saline. Alterations in nitric oxide (NO·) and peroxynitrite (ONOO(-)) levels, and nitric oxide synthase (NOS) enzyme activity were measured by biochemical methods in homogenized brain tissue of rats. Levels of NO· and ONOO(-), and enzyme activity of NOS in brain tissue of the rats treated with NSO or TQ were found to be lower than in received IR alone (p<0.002) Nigella sativa oil (NSO) and its active component, TQ, clearly protect brain tissue from radiation-induced nitrosative stress.

Antimutagenic Effect of Medicinal Plants Achillea millefolium and Bauhinia forficata In Vivo

The investigation of traditionally used medicinal plants is valuable both as a source of potential chemotherapeutic drugs and as a measure of safety for the continued use of these medicinal plants. Achillea millefolium L. (AM) is an ancient remedial herb native to Europe that is used to treat wounds, gastrointestinal and hepatobiliary disorders, inflammation, headaches, and pain. Bauhinia forficata Link (BF), an Asiatic plant, is one of the most commonly used plants in folk medicine against diabetes. The aim of this study was to evaluate the cytotoxic and antimutagenic potential of aqueous extracts of AM and BF on bone marrow cells of Wistar rats treated in vivo. These plant extracts possess considerable antioxidant activity due to the presence of flavonoids and phenolic compounds. These compounds were determinants to noncytotoxic and antimutagenic/protective action of these plants, that reduced statistically the percentage of chromosomal alterations induced by the chemotherapeutic agent cyclophosphamide in simultaneous (AM, 68%; BF, 91%), pre- (AM, 68%; BF, 71%), and post-treatment (AM, 67%; BF, 95%). Therefore, the results of this study indicate that extracts of A. millefolium and B. forficata have antimutagenic potential and that their consumption can benefit the health of those using them as an alternative therapy.

Nutraceutical properties of flour and tortillas made with an ecological nixtamalization process

The traditional nixtamalization (TN) process, used for obtaining maize-based products, negatively affects bioactive compounds because of its highly alkaline pH. Recently, an ecological nixtamalization (EN) process has been developed that retains the pericarp and maintains the nejayote (wastewater) within the acidic-neutral range. This study examines the effect of pH on the nutraceutical compounds (NC) of maize, such as polyphenolics and anthocyanins (ANT), as well as the effect on the antioxidant capacity (AC). The highest concentration of total phenolics (TP) in the maize kernel was found in the black and yellow genotypes, the highest concentration of ANT in the black genotypes, and the highest concentration of AC in the red and white genotypes. In the flour, TP levels were between 206 to 400 mg GA/100 g, ANT levels were 141 to 4107 mg cyanidin-3 glucoside/kg, and AC levels were 2544 to 3001 mg AA/kg. In tortillas, TP levels were 255 to 319 mg GA/100 g, ANT levels were 32 to 3420 mg cyanidin-3 glucoside/kg, and AC levels were from 1513 to 2695 mg AA/kg. The reduced loss of soluble solids, the pH, and the formation of compounds with proteins and carbohydrates from the EN process positively affected NC retention.

Protective effect ofBacopa monniera L. on cytarabine induced biochemical changes in chick embryo

Bacopa monniera, a medicinal plant distributed throughout India. Cytosine arabinoside (1-β-arabinofuranosylcytosine; Ara-C) is the most important antimetabolite chemotherapeutic drug used for acute leukemia. In this study we examined the chemoprotective property of an ethanolic extract of Bacopa monniera on biochemical changes in chick embryo. CA caused biochemical changes in a concentration and time dependent manner in amniotic fluid, liver and heart tissues. Ethanolic extract of BM given to chick embryo at doses of 2, 4, 6 mg per egg. There is significant decrease in biochemical levels of glucose, protein, urea, uric acid, creatinine and inorganic phosphorus. Enzymatic activities of alkaline phosphatase, lactate dehydrogenase, serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase and malatedehydrogenase were also decreased with dose dependent manner in amniotic fluid, liver and heart tissues.

Evaluation of toxicity, genotoxicity and environmental risk of simulated textile and tannery wastewaters with a battery of biotests

Textile and tannery wastewaters are complex mixtures of toxic pollutants and only a battery of ecotoxicity tests can assess their potential environmental impact and the actual effectiveness of alternative treatments. In this work the toxicity of four simulated textile and tannery wastewaters was evaluated by means of a battery of seven bioassays, using organisms that belong to different trophic levels. Moreover, since the outputs of the bioassay battery were quite difficult to compare, a novel synthetic index for environmental risk assessment was applied to the outputs of the test battery. All four simulated wastewaters were very toxic but they showed no mutagenic effect. The alga Pseudokirchneriella subcapitata was the most sensitive organism. In addition, the use of two mathematical models pointed out the interaction effect between dyes and salts, which resulted in a synergistic effect of wastewater toxicity.

Radioprotective effects of black seed (Nigella sativa) oil against hemopoietic damage and immunosuppression in gamma-irradiated rats

BACKGROUND AND AIM

Sixty male Wistar rats, divided into 4 groups, 15 each, were designed as I-control rats, II-rats orally intubated with Nigella sativa oil (1 ml/kg b.wt./day) for 5 days/week, III-whole body gamma irradiated rats with the estimated LD50/30 (4 Gray) and IV-rats daily intubated with Nigella sativa oil then subjected to whole body gamma irradiation, to investigate the radioprotective potential of Nigella crude oil against hemopoietic adverse effects of gamma irradiation.

RESULTS

Irradiation resulted in significant reduction in hemolysin antibodies titers and delayed type hypersensitivity reaction of irradiated rats, in addition to significant leukopenia and significant decrease in plasma total protein and globulin concentrations and depletion of lymphoid follicles of spleen and thymus gland. Furthermore, there was a significant increase in malondialdehyde concentration with a significant decrease in plasma glutathione peroxidase, catalase and erythrocyte superoxide dismutase activities were recorded. Oral administration of Nigella sativa oil before irradiation considerably normalized all the above-mentioned criteria; and produced significant regeneration in spleen and thymus lymphoid follicles.

CONCLUSION

Our results strongly recommend Nigella sativa oil as a promising natural radioprotective agent against immunosuppressive and oxidative effects of ionizing radiation.

New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

Synthesis, spectral and thermal studies of new rutin vanadyl complexes

Complexes between oxovanadium (IV) cation and flavonoid derivatives were developed recently in order to increase the intestinal absorption and to reduce the toxicity of vanadium compounds. For these reasons, is interesting to investigate the complexation process between flavonoid rutin (Rut) and vanadyl cation in order to isolate new complexes. Two new complexes [VO(Rut)(H2O)2](SO4)0.5 x 2 H2O and [VO(Rut)2] x 4 H2O have been obtained and characterized by elemental and thermal analyses and several spectroscopic techniques (ESI-MS, IR, UV-Vis, fluorescence). The studies concerning complex formation between vanadyl and rutin (Rut) performed in different solutions show the formation of mononuclear complexes with 1:1 and 1:2 metal to ligand stoichiometry.

Ameliorative effect of ajwain extract on hexachlorocyclohexane-induced lipid peroxidation in rat liver

Effect of ajwain extract on hexachlorocyclohexane-induced oxidative stress and toxicity in rats were investigated. Six groups of rats were maintained for 12 weeks as (1) Control; (2) HCH (300 mg/kg body weight) injected (3) 1% ajwain extract incorporated diet (4)1% ajwain extract incorporated diet+HCH (5) 2% ajwain extract incorporated diet and (6) 2% ajwain extract incorporated diet+HCH. Results revealed that HCH administration lead to an increase in hepatic lipid peroxidation associated with reduction in, levels of glutathione (GSH), activity of superoxide dismutase (SOD), catalase and glucose-6-phosphate dehydrogenase. Prefeeding of ajwain extract resulted in decreased hepatic levels of lipid peroxides and increased GSH, GSH-peroxidase, G-6-PDH, SOD, catalase and glutathione S-transferase (GST) activities. At the same time there was a significant reduction in hepatic levels of HCH-induced raise in lipid peroxides as a result of the prefeeding the extract. Prefeeding of ajwain extract at 1% level to rats injected with HCH reverted the significant changes in catalase, G-6-PDH, GST and -glutamyl transpeptidase. HCH-induced formation of micronuclei in femur bone marrow was also reduced significantly. It was concluded that HCH administration resulted in hepatic free radical stress, causing toxicity, which could be reduced by the dietary ajwain extract.

Acute oral safety study of rosemary extracts in rats

Increasing interest in rosemary plants is due to their antioxidant and health-enhancing properties. The aim of this study was to evaluate the potential acute toxicity of two supercritical fluid extracts of rosemary. An acute safety study of rosemary extracts was conducted in Wistar rats at a single oral gavage dosage of 2,000 mg/kg of body weight. Rosemary extracts were well tolerated; no adverse effects or mortality were observed during the 2-week observation period. No abnormal signs, behavioral changes, body weight changes, or change in food and water consumption occurred. Two weeks after a single oral rosemary extract dose of 2,000 mg/kg of body weight, there were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. Rosemary extracts appear to have low acute toxicity, and the oral lethal doses (LD50) for male and female rats are greater than 2,000 mg/kg of body weight.

Isolation of chlorogenic acids and their derivatives from Stemona japonica by preparative HPLC and evaluation of their anti-AIV (H5N1) activity in vitro

Two chlorogenic acids and five chlorogenic acid derivatives were simultaneously separated and purified from Stemona japonica by preparative high-performance liquid chromatography. Five of the collected compounds were over 95% pure while the other two compounds were over 90% pure. Their structures were elucidated as 3-O-feruloylquinic acid (1), 4-O-feruloylquinic acid (2), methyl 3-O-feruloylquinate (3), methyl 5-O-caffeyolquinate (4), methyl 4-O-feruloylquinate (5), ethyl 3-O-feruloylquinate (6) and the new compound ethyl 4-O-feruloylquinate (7) by UV, NMR and ESI-MS. All compounds were obtained from Stemona species for the first time, however compounds 6 and 7 are believed to be artefacts from the ethanol extraction. The anti-AIV (H5N1) activities were evaluated by Neutral Red uptake assay. Compounds 3 and 4 exerted moderate inhibitory effect against AIV (H5N1) in vitro.

Induction of apoptosis by ginger in HEp-2 cell line is mediated by reactive oxygen species

Ginger (Zingiber officinale Roscoe, Zingiberaceae) is a commonly used medicinal herb throughout the world. Although some studies have demonstrated its antitumour activities on cancer cells in vitro and in vivo, the exact mechanism is not fully elucidated. Hence, the present study was designed to examine the in vitro cytotoxic activities of saline extract prepared from ginger extract on HEp-2 cell line. The cytotoxic effect of the drug was confirmed by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and cell counting and estimation of protein, DNA and RNA. Meanwhile, propidium iodide staining and agarose gel electrophoresis were performed for determining the induction of apoptosis. In addition, superoxide radical generation, nitrite formation and glutathione studies show involvement of free radicals. The present results show that the extract exerts dose-dependent suppression of cell proliferation; the IC(50) value was found to be 900 microg/ml. At a dose of 250 microg/ml, marked morphological changes including cell shrinkage and condensation of chromosomes were observed. Agarose gel electrophoresis of DNA from HEp-2 cells treated with 250 microg/ml ginger powder for 24 hr showed marked DNA ladder pattern. The involvement of free radicals was confirmed by increased superoxide production, decreased nitrate formation and depletion of glutathione in ginger-treated cells. Further screening of active components using gas chromatography-mass spectrometry analyses showed the presence of clavatol, geraniol and pinostrobin in the extract. The results of the present study suggest that ginger might be useful as a potential antitumour agent.

Relationship among antimutagenic, antioxidant and enzymatic activities of methanolic extract from common beans (Phaseolus vulgaris L)

Common beans are rich in phenolic compounds, which can provide health benefits to the consumer. The objective of this work was to study the relationship among antimutagenicity, antioxidant and enzymatic activities of methanolic extract and trolox by principal components multivariate analysis. Antimutagenicity of phenolic compounds present in methanolic extract from the seed coat of common beans (P. vulgaris, Flor de Mayo Bajío cultivar) and trolox against AFB1 mutagenicity were evaluated in the Salmonella typhimurium microsuspension assay. Antioxidant capacity of methanolic extract and trolox were evaluated using beta-carotene and 1,1-diphenyl-2-picryhydrazyl (DPPH) in vitro model assays. Cythrome P450 activity was measured by fluorometric assay. For phenolic extract, trolox and phenolic extract+trolox, the inhibition on AFB1 mutagenicity in tester strain TA100 was 47, 59 and 69%, respectively. While in TA98 was 39, 48 and 68%. The inhibition of phenolic compounds, trolox and phenolic compounds+trolox on cytochrome P450 (CYP450) activity was 48, 59 and 88%, respectively. Correlation analysis showed that phenolic extract and trolox have high antimutagenic and antioxidant activity and also inhibited enzymatic activity. The results suggest that the primary mechanism of action of phenolic compounds in beans against AFB1 mutagenicity may be extra-cellular in the microsuspension assay.

Tangeretin suppresses IL-1beta-induced cyclooxygenase (COX)-2 expression through inhibition of p38 MAPK, JNK, and AKT activation in human lung carcinoma cells

Tangeretin (5,6,7,8,4'-pentamethoxyflavone) is a polymethoxylated flavonoid concentrated in the peel of citrus fruits. Recent studies have shown that tangeretin exhibits anti-proliferative, anti-invasive, anti-metastatic, and antioxidant activities. However, the anti-inflammatory properties of tangeretin are unclear. In this study, we examine the effects of tangeretin and its structure-related compound, nobiletin, on the expression of cyclooxygenases-2 (COX-2) in human lung epithelial carcinoma cells, A549, and human non-small cell lung carcinoma cells, H1299. Tangeretin exerts a much better inhibitory activity than nobiletin against IL-1beta-induced production of COX-2 in A549 cells, and it effectively represses the constitutively expressed COX-2 in H1299. RT-PCR was used to investigate the transcriptional inhibition of COX-2 by tangeretin. COX-2 mRNA was rapidly induced by IL-1beta in 3h and markedly suppressed by tangeretin. IL-1beta-induced the activation of ERK, p38 MAPK, JNK, and AKT in A549 cells. COX-2 expression in response to IL-1beta was attenuated by pretreatment with SB203580, SP600125, and LY294002, but not with PD98059, suggesting the involvement of p38 MAPK, JNK, and PI3K in this response. Pretreatment of cells with tangeretin inhibited IL-1beta-induced p38 MAPK, JNK, and AKT phosphorylation and the downstream activation of NF-kappaB. These results may reveal that the tangeretin inhibition of IL-1beta-induced COX-2 expression in A549 cells is, at least in part, mediated through suppression of NF-kappaB transcription factor as well as through suppression of the signaling proteins of p38 MAPK, JNK, and PI3K, but not of ERK.

Curcumin improves wound healing by modulating collagen and decreasing reactive oxygen species

Wound healing consists of an orderly progression of events that re-establish the integrity of the damaged tissue. Several natural products have been shown to accelerate the healing process. The present investigation was undertaken to determine the role of curcumin on changes in collagen characteristics and antioxidant property during cutaneous wound healing in rats. Full-thickness excision wounds were made on the back of rat and curcumin was administered topically. The wound tissues removed on 4th, 8th and 12th day (post-wound) were used to analyse biochemical and pathological changes. Curcumin increased cellular proliferation and collagen synthesis at the wound site, as evidenced by increase in DNA, total protein and type III collagen content of wound tissues. Curcumin treated wounds were found to heal much faster as indicated by improved rates of epithelialisation, wound contraction and increased tensile strength which were also confirmed by histopathological examinations. Curcumin treatment was shown to decrease the levels of lipid peroxides (LPs), while the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), activities were significantly increased exhibiting the antioxidant properties of curcumin in accelerating wound healing. Better maturation and cross linking of collagen were observed in the curcumin treated rats, by increased stability of acid-soluble collagen, aldehyde content, shrinkage temperature and tensile strength. The results clearly substantiate the beneficial effects of the topical application of curcumin in the acceleration of wound healing and its antioxidant effect.

Preliminary study on inhibition of genotoxicity by piperine in mice

A significant suppression (33.9-66.5%) in the micronuclei formation induced by benzo(a)pyrene and cyclophosphamide was reduced following oral administration of piperine at doses of 25, 50 and 75 mg/kg in mice.

Chemopreventive efficacy of ginger, a naturally occurring anticarcinogen during the initiation, post-initiation stages of 1,2 dimethylhydrazine-induced colon cancer

BACKGROUND

Ginger (Zingiber officinale Rosc) is a natural dietary component, which has antioxidant and anticarcinogenic properties. We investigated the effect of ginger on the initiation and post-initiation stages of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in male Wistar rats.

METHODS

Rats were given a weekly subcutaneous injection of DMH (20 mg/kg body weight) in the groin for 15 weeks. Ginger (50 mg/kg body weight/everyday p.o.) was given to the rats at the initiation, post-initiation stages of carcinogenesis. The activity of lipid peroxidation was studied by measuring the formation of thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH) and conjugated dienes (CD), and the antioxidant status by measuring superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione-S-transferase (GST), glutathione reductase (GR), reduced glutathione (GSH), vitamins C, E, and A concentrations in the circulation of 1,2-dimethylhydrazine-induced experimental colon cancer.

RESULTS

In the presence of a known colon carcinogen, DMH, plasma lipid peroxidation (TBARS, lipid hydroperoxides and conjugated dienes) and cancer incidence were significantly increased whereas enzymic (GPx, GST, GR, SOD and CAT) and non-enzymic antioxidant concentrations (GSH, vitamins C, E, and A) were decreased as compared to control rats. The number of tumors as well as the incidence of cancer was significantly decreased on treatment with ginger. In addition, ginger supplementation at the initiation stage and also at the post-initiation stages of carcinogenesis significantly reduced circulating lipid peroxidation and significantly enhanced the enzymic and non-enzymic antioxidants as compared to unsupplemented DMH-treated rats.

CONCLUSIONS

Ginger supplementation suppresses colon carcinogenesis in the presence of the procarcinogen DMH.

Cactus stems (Opuntia spp.): A review on their chemistry, technology, and uses

Although traditionally used as a valuable health supporting nutrient, the vegetative parts of Opuntia spp. plants are scarcely used in modern nutrition and medicine. While all kinds of different Opuntia spp. have been studied, a systematic approach regarding the inter-relationships between the composition and the pre- and postharvest conditions is still missing. Therefore, the present review compiles and discusses literature on the chemical composition of cactus stems, the knowledge on uses in food, medicine, and cosmetics. It is concluded that much research is needed to get an insight into the multitude of bioactivities reported in the traditional literature but also to take advantage of the respective constituents for food and pharmaceutical applications.

Bioavailability of Phenolic Compounds

Phenolic compounds in foods originate from one of the main classes of secondary metabolites in plants. They are essential for the growth and reproduction of plants, and are produced as a response for defending injured plants against pathogens. In recent years, there is a growing interest in phenolic compounds and their presumed role in the prevention of various degenerative diseases, such as cancer and cardiovascular diseases. The importance of antioxidant activities of phenolic compounds and their possible usage in processed foods as a natural antioxidant have reached a new high in recent years. The absorption and bioavailability of phenolics in humans are also controversial. Data on these aspects of phenolics are scarce and merely highlight the need for extensive investigations of the handling of phenolics by the gastrointestinal tract and their subsequent absorption and metabolism. In this article, absorption, metabolism, and the bioavailability of pheniolic compounds are reviewed.