Article

Does an Extract of Carob ( Ceratonia siliqua L. ) Have Chemopreventive Potential Related To Oxidative Stress and Drug Metabolism in Human Colon Cells?

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Abstract

Phenolic ingredients of an aqueous carob extract are well characterized and consist of mainly gallic acid (GA). In order to assess possible chemopreventive mechanisms of carob, which can be used as a cacao substitute, effects on expression of genes related to stress response and drug metabolism were studied using human colon cell lines of different transformation state (LT97 and HT29). Stress-related genes, namely catalase (CAT) and superoxide dismutase (SOD2), were induced by carob extract and GA in LT97 adenoma, but not in HT29 carcinoma cells. Although corresponding protein products and enzyme activities were not elevated, pretreatment with carob extract and GA for 24 h reduced DNA damage in cells challenged with hydrogen peroxide (H(2)O(2)). In conclusion, carob extract and its major phenolic ingredient GA modulate gene expression and protect colon adenoma cells from genotoxic impact of H(2)O(2). Upregulation of stress-response genes could not be related to functional consequences.

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... The carob extract pods have shown a high inhibition on human colon cell lines growth, but the effect on DNA-synthesis was less pronounced in HT29 adenocarcinoma than LT97 adenoma cells, certainly due to different growth kinetics [52]. The aqueous extract of carob induces a significant reduction of the number of human colon cancer HT29 cells at the concentration of 10 mg/mL [12]. At 20 µg/mL, C. siliqua leaf extract induces the phosphorylation of p38 MAPK and p53 proteins in HCT-116 and CT-26 colon cancer cells via the activation of caspase-9 in order to induce apoptosis. ...
... Since polyphenols are well described for their antioxidant capacity, Klenow and coll. investigated the ability of carob extract to protect LT97 and HT29 cells against H 2 O 2 inducer of DNA damage [12]. Sugars, particularly sucrose and glucose, may mask the cytotoxicity of other bioactive components and contribute to the reduction of anticarcinogenic capacity of such extract [54]. ...
... Sugars, particularly sucrose and glucose, may mask the cytotoxicity of other bioactive components and contribute to the reduction of anticarcinogenic capacity of such extract [54]. This study found that carob reduces the growth of HT29 colon carcinoma and LT97 colon adenoma cells via the modulation of CAT and SOD2 gene expression, as well as the detoxification of ROS, which are associated with the colorectal carcinogenesis [12]. In order to determine an accurate IC 50 value for seeds extracted on proapoptotic activity and intracellular ROS released by LOVO cells, we need to test lower concentrations of our extracts, to assess possible gene modulation expression related to the stress response. ...
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The present work describes the volatile compounds profile and phytochemical content of Ceratonia siliqua L. Fifty different components have been identified. Among them, three constituents are shared i.e., 2-methlybutanoic acid, methyl hexanoate and limonene by different common carob preparations: pulp decoction (PD), seeds decoction (SD) and Rob, a sweet syrup extracted from the pulp of the carob pod. Each extract exhibits different volatile aromatic emission profiles. The antioxidant activity of the extracts was evaluated using three methods, DPPH, ABTS and FRAP, producing a dose-dependent response. The IC50, when determined by FRAP, gave the lowest values (0.66 ± 0.01, 0.73 ± 0.05 and 0.55 ± 0.00 mg/mL PD, SD and Rob, respectively). The nociception essay, after intraperitoneal injection of acetic acid in mice, demonstrated that Rob, pulp and seeds decoction extracts showed an efficient inhibition of writhes over time, with persistence over 30 min. The SD decoction revealed the highest efficacy in decreasing the writhing reflex (90.3 ± 1.2%; p < 0.001). Furthermore, the proapoptotic activity of SD against three human cell line, THP-1, MCF-7 and LOVO, evaluated by flow cytometry, showed a significantly stronger proapoptotic activity on colon cancer (LOVO) than on the other cell lines, a phenomenon known as phenotypic selectivity.
... Some of the molecules have high bioavailability after being ingested and exert biological effects [13]. The effective compounds are further categorized into eight subtypes as shown in Fig. 1a, flavones (compounds [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], flavonols (compounds [21][22][23][24][25], isoflavones (compounds [26][27][28][29][30], flavanones (compounds [31][32][33][34][35], chalcones (compounds [36][37][38][39][40][41][42][43][44][45], anthocyanidins (compounds [46][47], and flavanonols (compounds [48][49][50][51][52][53][54][55][56], xanthones (compounds 57 and 58) [13,[16][17][18][19][20][21][22][23][24][25][26][27][28][31][32][33][34][35][36][37][38][39][40][41]. ...
... Some of the molecules have high bioavailability after being ingested and exert biological effects [13]. The effective compounds are further categorized into eight subtypes as shown in Fig. 1a, flavones (compounds [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], flavonols (compounds [21][22][23][24][25], isoflavones (compounds [26][27][28][29][30], flavanones (compounds [31][32][33][34][35], chalcones (compounds [36][37][38][39][40][41][42][43][44][45], anthocyanidins (compounds [46][47], and flavanonols (compounds [48][49][50][51][52][53][54][55][56], xanthones (compounds 57 and 58) [13,[16][17][18][19][20][21][22][23][24][25][26][27][28][31][32][33][34][35][36][37][38][39][40][41]. ...
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Purpose of Review Although great progress continues to be made against cancer, it remains the second leading cause of death in the world. As pointed out in the World Cancer Report 2014, elucidating the causes and devising effective prevention strategies are essential components of cancer control. Hence, in this review, we focus on effective and safe cancer chemopreventive reagents, which could reverse the processes of initiation and subsequent progression of cancer. Recent Findings Natural products from traditional herbals and food, consumed with years of history, have attracted much attention because of their safety, efficacy, and potency for cancer chemoprevention. Based on 119 references, we collected 179 chemopreventive phytochemicals, including flavonoids, terpenoids, alkaloids, phenylpropanoids, and stilbenes. In our recent research, we have also reported a series of novel chemopreventive reagents from Traditional Chinese Medicines and functional food. Summary This review has summarized the latest research on the bioactive natural products reported as chemopreventive reagents in vitro or in vivo. The research results could throw light on further study for accurate prevention strategies against cancer. Furthermore, the functional factors from the food suggested more healthful dietary pattern for the special group.
... 25 Leaves and pods of carob exerted diverse physiological functions such as its antioxidant activity. [26][27][28][29][30][31][32][33] Indeed, the extracts of the carob tree showed signicant radical scavenging activity 34 and a remarkable ability to inhibit tumor cell proliferation. 26 Carob tree extracts contain anti-proliferative agents that could be of practical importance in the development of functional foods and/or chemopreventive drugs. ...
... 26 Carob tree extracts contain anti-proliferative agents that could be of practical importance in the development of functional foods and/or chemopreventive drugs. 33 In addition, leaves and pods of carob are rich in polyphenols and avonoids. 35 The aim of the present study was to examine the effect of carob tree leaves aqueous extract (CSLAE) on ROS production and MPO activity and expression in vitro as well as its protective effect on castor oil-induced small intestinal hypersecretion in rat. ...
Article
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Chronic inflammation and oxidative stress are induced by biological, chemical and physical factors which are, in turn, associated with an increased risk of several human diseases. Plants are a large source of new bioactive molecules with therapeutic potential. In this respect, the present study was designed to investigate the effects of a Ceratonia siliqua L. leaf aqueous extract (CSLAE) on human neutrophil reactive oxygen species (ROS) production, in vitro myeloperoxidase (MPO) activity and expression as well as the small intestinal fluid and electrolyte secretion. Neutrophils were isolated from whole human blood of healthy volunteers using the ficoll-dextran method and ROS generation and H2O2 were measured by luminol amplified chemiluminescence. Superoxide anion generation was also detected by chemiluminescence using the lucigenin method. MPO activity and quantity were measured by the tetramethylbenzidine oxidation method and Western blotting analysis. Concerning the in vivo part, fasted male rats received by gavage either the vehicle (NaCl, 0.9%), the extract at various doses (50, 100 and 200 mg kg⁻¹) or clonidine (1 mg kg⁻¹). An activated charcoal suspension was administered by oral gavage. Thirty minutes after receiving the charcoal meal, rats were euthanized and the small intestine was removed. The length of the small intestine and the distance traveled by the charcoal were recorded. Castor oil-induced hypersecretion in Wistar rats was treated with administration of CSLAE (50, 100 and 200 mg kg⁻¹) and antidiarrheal drug, Atropine (0.1 mg kg⁻¹ i.p.). CSLAE inhibited luminol-amplified chemiluminescence of (PMA)-stimulated neutrophils in a concentration-dependent manner and is able to scavenge superoxide anions and hydrogen peroxide. The CSLAE also reduces significantly and dose-dependently MPO activity and expression. On the other hand, in vivo studies showed that the CSLAE decreased notably and dose-dependently the GIT activity, intestinal fluid and electrolyte concentration. The chemical analysis using a HPLC technique showed that the CSLAE is rich in phenolic compounds, especially kaempferol, tannic acid and catechin hydrate. The intended neutrophil inhibition is introduced as a part of a new strategy for pharmacological modulation of chronic inflammatory and oxidative stress processes. On the basis of these findings, it can be also assumed that CSLAE could be a potential source for novel discovery for antidiarrhoeal drug development. This journal is
... On one hand, the n-hexane, methanol, ethanol, ethyl acetate and water extracts of carob leaves have shown ant m crob al e ects on many m croorgan sms nclud ng Escher ch a col , Staphylococcus aureus, Staphylococcus ep derm d s, Salmonella thyph mur um, Enterobacter cloacae, Enterococcus faecal s, Pseudomonas aerog nosa and Cand da alb cans, and on another hand, these extracts demonstrated cytotox c e ect agan st br ne shr mp [18]. Klenow et al. (2009) [19] have revealed that carob extracts are capable to prevent the ox dat ve stress, espec ally n human colon. The carob pod has d splayed gastroprotect ve e ect due to ts strong ant ox dant act v ty [20]. ...
... On one hand, the n-hexane, methanol, ethanol, ethyl acetate and water extracts of carob leaves have shown ant m crob al e ects on many m croorgan sms nclud ng Escher ch a col , Staphylococcus aureus, Staphylococcus ep derm d s, Salmonella thyph mur um, Enterobacter cloacae, Enterococcus faecal s, Pseudomonas aerog nosa and Cand da alb cans, and on another hand, these extracts demonstrated cytotox c e ect agan st br ne shr mp [18]. Klenow et al. (2009) [19] have revealed that carob extracts are capable to prevent the ox dat ve stress, espec ally n human colon. The carob pod has d splayed gastroprotect ve e ect due to ts strong ant ox dant act v ty [20]. ...
Conference Paper
Carob (Ceratonia siliqua L.) belongs to the Leguminosae family and is mostly cultivated in the Mediterranean and Mediterranean-like areas. Carob fruit is constituted mainly by the pulp and seeds. Carob beans are used as food with great industrial interest for both human and animals. The beans are processed into essential oils, gums, molasse, syrup, confectionery products, biscuits, cakes and juice. The beans have high nutritional value as they contain a considerable amount of protein, fat, carbohydrates, minerals, dietary fiber and vitamins. They are rich in sugar and contain essential bioactive such as phenolic acids, proanthocyanins and tannins. The extracts of carob demonstrated strong antioxidant and antimicrobial activities. Indeed, they are used to prevent or to heal ailments such as asthma attacks, bronchitis, flu, cough, diarrhea, cancer, cholesterol and cardiovascular diseases. The volatile compounds which provide the overall odor of carob beans are mainly aliphatic acids, alcohols, aldehydes, esters, ketones, lactones, furans, phenols, pyrroles, pyridines, pyrazines and terpenes. This paper highlighted the multipurpose uses, phytochemical and aroma compounds of carob beans that could be used as a nutritional supplement into other foods.
... 25 Leaves and pods of carob exerted diverse physiological functions such as its antioxidant activity. [26][27][28][29][30][31][32][33] Indeed, the extracts of the carob tree showed signicant radical scavenging activity 34 and a remarkable ability to inhibit tumor cell proliferation. 26 Carob tree extracts contain anti-proliferative agents that could be of practical importance in the development of functional foods and/or chemopreventive drugs. ...
... 26 Carob tree extracts contain anti-proliferative agents that could be of practical importance in the development of functional foods and/or chemopreventive drugs. 33 In addition, leaves and pods of carob are rich in polyphenols and avonoids. 35 The aim of the present study was to examine the effect of carob tree leaves aqueous extract (CSLAE) on ROS production and MPO activity and expression in vitro as well as its protective effect on castor oil-induced small intestinal hypersecretion in rat. ...
... doi:10.1016/j.supflu.2011.08.007 antioxidative potential and improved digestion and lipid utilization [18,19]. Also, a few studies on the pharmacological activity potential of compounds found in carob extracts have been reported with promising results, such as in vitro antiproliferative effects on mouse hepatocellular carcinoma cell line [20], in human colon adenocarcinoma and adenoma cells [21,22], in cervical (HeLa) cacer cells [23], and on rat N1E-115 neuroblastoma cells, on human HeLa cervical and MCF-7 breast cancer cell lines [24]. ...
... The influence of several parameters on yield was studied. The parameters analysed were: pressure in the ranges [15][16][17][18][19][20][21][22] MPa, at temperatures between 40 • C and 70 • C, particle size, and SC-CO 2 flow rate. The extracts were characterised in terms of antioxidant capacity by DPPH method, total phenolics content by the Folin-Ciocalteu method, and the phenolic profile of the extract was qualitatively evaluated by HPLC-DAD. ...
Article
Carob pulp kibbles, a by-product of carob been gum production, was studied as a source of bioactive agents. Firstly, the carob kibbles were submitted to an aqueous extraction to extract sugars, and supercritical fluid extraction (SFE) was applied to the solid residue of that aqueous extraction, by using compressed carbon dioxide (SC-CO2) as the solvent and a mixture of ethanol and water (80:20, v/v) as a co-solvent. Pressure and temperature were studied in the ranges 15–22MPa, and 40–70°C. Particle diameter, and co-solvent percentage in ranges of 0.27–1.07mm, and 0–12.4%, respectively, were also studied, as well as the flow rate of SC-CO2 between 0.28 and 0.85kgh−1, corresponding, respectively, to 0.0062 and 0.0210cms−1 of superficial velocity. The extracts were characterised in terms of antioxidant capacity by DPPH method, and total phenolics content by the Folin–Ciocalteu method. The central composite non-factorial design was used to optimise the extraction conditions, using the Statistica, version 6 software (Statsoft). The best results, in terms of yield and antioxidant capacity, were found at 22MPa, 40°C, 0.27mm particle size, about 12.4% of co-solvent and a flow rate of 0.29kgh−1 of SC-CO2. The phenolics profile of the extracts obtained at these conditions was qualitatively evaluated by HPLC-DAD. The solid residue of the supercritical extraction was also studied showing to be a dietary fiber, which can be compared to Caromax™, a carob fiber commercialised by Nutrinova Inc.
... On the other hand, the frequencies of CAs decreased in a dose-dependent manner, when carob extracts were co-administered with Co(NO 3 ) 2 . Previous studies were in accordance with our results about genoprotective role of carob extract (Sassi et al. 2016;Klenow et al. 2009;Azab 2017). Klenow et al. (2009) interpreted this protective action as a result of high phenolic and gallic acid content that are great antioxidants. ...
... Previous studies were in accordance with our results about genoprotective role of carob extract (Sassi et al. 2016;Klenow et al. 2009;Azab 2017). Klenow et al. (2009) interpreted this protective action as a result of high phenolic and gallic acid content that are great antioxidants. ...
Article
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Cobalt (Co) is widely used in many industrial fields such as batteries and paints. Cobalt, a dangerous heavy metal, can be found in high concentrations in natural and human habitats. Although cobalt is an important micronutrient, it is toxic to living organisms when exposed to high amounts. Carob (Ceratonia siliqua L.) is a tree native to The Mediterranean region. Carob bean, which has high nutritional and economic value, is used against cardiovascular and gastrointestinal diseases. In addition, the antioxidant properties of carob are gaining importance in recent years. In this study, the protective effects of carob extract against the toxicity of cobalt on Allium cepa L. were investigated. For this purpose, 150 mg/L and 300 mg/L carob extract solutions and 5.5 mg/kg cobalt solutions were applied to A. cepa L. bulbs. Root emergence, weight gain, root elongation, and mitotic index (MI) decreased, while the frequency of chromosomal abnormalities (CAs) and micronucleus (MN) increased as a result of Co application. Furthermore, Co treatment triggered a noticeable rise in the activities of superoxide dismutase (SOD) and catalase (CAT) enzymes as well as the malondialdehyde (MDA) amount and the abnormalities in the meristematic cells. On the other hand, applications of carob extracts mitigated cobalt-induced damages in a dose-dependent manner in all parameters. Therefore, the current study showed that the strong preventive potential of carob extract against phytotoxicity and genotoxicity is caused by Co in a model plant. The protective effects of carob extract on Co-induced toxicity were demonstrated for the first time in terms of reducing genotoxicity and oxidative stress response.
... This antioxidant activity eliminates free radicals, prevents the active metabolite of cyclophosphamide, and removes them. Therefore, removal of the active metabolite of cyclophosphamide prevents inhibition of mitotic and meiotic divisions within the testis, and the number of sperm cells through elevating the dose of Ceratonia siliqua L. extract is increased [7,18]. Treating mice with Ceratonia siliqua L. extract increased the viability and motility of sperm which may be due to the reduction in the level of reactive oxygen species. ...
... The inflammation reduces the body's antioxidant defense power which could adversely affect the sperm parameters [18]. Various studies have reported that antioxidants as supplements reduced inflammatory factors and MDA level [4,15,32]. ...
Article
This study was conducted to determine the effects of Ceratonia siliqua L. (CS) extract on sperm parameters and DNA damage in adult male mice treated with cyclophosphamide (CP). Based on an initial dose response experiment on Ceratonia siliqua L. extract, five treatment groups were set up: control, sham (normal saline: 0.2 ml per day, IP), CP (15 mg kg-1 per week; IP), Ceratonia siliqua L. (100mg l-1 per day; IP), and group of Ceratonia siliqua L. along with CP for 35 days. After euthanizing the animals, sperms from caudal part of epididymis were collected, and their parameters, Malone Di-Aldehyde (MDA) level, and DNA fragmentation were analyzed. In the mice exposed to cyclophosphamide, reduction in the sperm count and viability and increase in the abnormal sperm and MDA levels were detected (p < .05). In addition, an increase in sperms with damaged DNA was detected in CP group, while the use of Ceratonia siliqua L. Extract significantly recovered these disturbances in the treatment group (p < .05). This study suggested the competence of Ceratonia siliqua L. extract in the improvement of sperm parameters and DNA fragmentation in animals treated with CP.
... Clinical beneficial effect on improving the glycemic profile without severe adverse effects in type 2 diabetic patients [106] continued next page Flavonoids: mainly myricetin [108]. Phenolics: mainly gallotannins and proanthocyanidins, tannins, flavonol-glycosides, and traces of isoflavonoids [109][110][111][112]. Tannins [113] Significantly decreased the glucose response to and glycemic index of fibers-enriched food in type 2 diabetic subjects. ...
Article
Diabetes mellitus is the most common metabolic disorder affecting millions worldwide. It is recognized as a global major health problem. As alternatives to the available orthodox medicines, plants are considered a potential source for the treatment of diabetes within traditional ethnomedicine practices. In the Jordanian traditional medicine a significant selection of ethnobotanicals is promoted for their antidiabetic activity. Literature surveys demonstrate the benefit of several ethnobotanicals as antidiabetic agents evaluated in in vitro and in vivo systems in the form of their crude extracts and/or isolated pure compounds with varying degrees of hypoglycemic or antihyperglycemic bioactivities. This mini review discusses the preparatory forms in which these plants are consumed, their reported phytoconstituents, and the results of their reported antidiabetic bioactivity.
... The biological activities of a crude extract can be due to a natural mixture of its components, and a single constituent may not have an activity greater than that of the total extract as a whole (Salucci et al., 2002; Búfalo et al., 2010). In order to investigate the in vitro cytotoxic activity of the extract phenolic constituents, all the phenolic compounds identified in the extract were evaluated in the viability assay at concentrations equivalent to the ones quantified in the crude extract (Klenow et al., 2009). After 24 h of incubation, GA exhibited the strongest cytotoxic activity, reducing HeLa cells viability to 11.1% (Figure 3). ...
Article
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This research evaluated the in vitro apoptotic inducing properties of a methanol leaf extract of carob tree (Ceratonia siliqua L.) on a human cervical adenocarcinoma cell line (HeLa). The cell viability effect on a prostate (DU-145), breast (MDA-MB-231) and colon cell line (HCT-166) was also assessed. The effect of the extract on reactive oxygen species (ROS) production by HeLa cells was studied, and a phytochemical evaluation was made by high performance liquid chromatography with diode array detection (HPLC). Total mean yield of identified phenols was 261.1 mg/g DW, and (+)-catechin was the major compound (76.8 mg/g DW). The extract decreased cell viability in a dose-and time-dependent manner, and a more pronounced effect on HeLa line was observed. In vitro cytotoxic activity was associated with apoptosis, but not to the increase of ROS production. Among the tested compounds identified in the extract, the highest activity was detected with gallic acid (GA), (+)-catechin and quercetin, with reductions in HeLa cells viability down to 8.0, 11.9 and 27.1%, respectively. This is the first report on the apoptotic activity of a leaf extract of carob tree on a human cancer cell line, suggesting that it may be a potential source of chemopreventive compounds.
... This low-cost by-product is highly rich in valuable compounds, particularly polyphenols, which have been described to present antioxidant activity and a diversity of potential health benefits in humans. For example, carob preparations have been described to exhibit total and LDL cholesterol lowering properties in hypercholesterolemic patients (Zunft et al., 2001(Zunft et al., , 2003, antioxidant properties (Kumazawa et al., 2002;Makris and Kefalas, 2004) and an elicitation of natural antioxidant defences (Klenow et al., 2009), as well as beneficial effects in energy intake and body weight (Gruendel et al., 2006(Gruendel et al., , 2007a(Gruendel et al., , 2007b. Other few studies also refer to the inhibition of tumor cells proliferation e.g. ...
Article
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A new approach to the extraction of bioactive phenolic compounds from carob kibbles has been proposed. Carob pulp kibbles, a by-product of the carob bean gum production, were subject to supercritical fluid extraction (SFE) and to ultrasound assisted (UAE) and conventional solid-liquid extractions with two different solvent systems (100% H2O and 70% acetone), in order to obtain phenolic rich extracts with biological activities. These extracts were characterized for total phenolics content, antioxidant activity and their phenolic profile was qualitatively evaluated by HPLC-DAD. Chromatographic profile of SFE extract showed a diversity of phenolic compounds while ultrasound and conventional extracts contained mainly gallic acid. The highest phenolics concentration and antioxidant capacity was also found in the SFE extract. Preliminary screening of the extracts antiproliferative activity on rat N1E-115 neuroblastoma cells, and on human HeLa cervical and MCF-7 breast cancer cell lines revealed that carob SFE extract exhibited a much higher antiproliferative effect in the studied tumor cells, indicating its greater potential as a source of natural antitumor compounds. Supercritical fluid extraction revealed to be a more selective and efficient method of extraction. Thus, the potential association of two environmentally clean processes (UAE and SFE) for obtaining polyphenols from carob kibbles will enable bioactive compounds within an integrated and sustainable recovery process. Also, the solid residue after extractions could be used as dietary fiber.
... Both the phenolic compounds present in the extract and the synergistic mechanisms between them may be responsible for the antioxidant activity displayed by carob germ flour. Extracts from leaves and fruit pulps from carob tree reduce cell viability of different cancer cell lines [7, 18, 24, 25]. This work provides the first evidence of in vitro cytotoxic activity of carob germ flour extracts on HeLa cells. ...
Article
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This work aimed to evaluate the phytochemical content and to determine the antioxidant and cytotoxic activities of methanol extracts of the carob tree (Ceratonia siliqua L.) germ flour. The extracts were rich in phenolic compounds, had considerable antioxidant activity, and reduced the viability of cervical (HeLa) cancer cells. The chemical content and the biological activities of the extracts were significantly affected by gender and cultivar. Female cultivar Galhosa had the highest levels of phenolic compounds, and the highest antioxidant activity. Extracts from the hermaphrodite trees and from the female cultivars Galhosa and Costela/Canela exhibited the highest cytotoxic activity. The most abundant compound was theophylline. The phenolic content was correlated to both antioxidant and cytotoxic activities. Our findings provide new knowledge about the health implications of consuming food supplemented with carob germ flour.
... Clinical beneficial effect on improving the glycemic profile without severe adverse effects in type 2 diabetic patients [106] continued next page Flavonoids: mainly myricetin [108]. Phenolics: mainly gallotannins and proanthocyanidins, tannins, flavonol-glycosides, and traces of isoflavonoids [109][110][111][112]. Tannins [113] Significantly decreased the glucose response to and glycemic index of fibers-enriched food in type 2 diabetic subjects. It also tended to decrease their insulinemic response and insulinemic index [114]. ...
... Namely, water extraction of the carob powder yields a product that contains mostly dietary fibre, as well as a phenolic fraction consisting of water-soluble and insoluble tannins, flavonol glycosides, and high contents of different forms of gallic acid (GA): free GA, gallotannins, and methyl gallate (Papagiannopoulos, Wollseifen, Mellenthin, Haber, & Galensa, 2004). Recent scientific investigations showed that carob pod extracts possess strong antioxidant activity (Kumazawa et al., 2002), modulates blood lipid profile in humans (Gruendel et al., 2007) reduces growth of different cell lines (Klenow, Glei, Haber, Owen, & Pool-Zobel, 2008) and modulates gene expression and protects colon adenoma cells from genotoxic impacts (Klenow, Jahns, Pool-Zobel, & Glei, 2009) making it an interesting raw material to be used in development of food additives, functional foods and dietary supplements. Commercially, such extracts are already being used as natural and safe antioxidants by the food industry (Bastida et al., 2009). ...
Article
Antioxidant activity, gastrointestinal solubility of polyphenols and formation of different classes of Maillard reaction products (MRPs) that occurs during thermal processing of carob powder was investigated in relation to different roasting time-roasting temperature combinations applied. Principal component analysis (PCA) was used to group carob powders with the aim of proposing optimal roasting conditions for obtaining the one with the highest biological activity that can be expected after undergoing the simulation of gastrointestinal digestion. Results showed that antioxidant activity of carob powder can be significantly increased by roasting due to improved polyphenol solubility and formation of the early-stage MRPs. Fluorescent MRPs, HMF and furfural, known for their toxic properties, were the most abundant in samples roasted under more severe time/temperature conditions. Carob powder roasted at 130 °C for 30 min yielded the highest antioxidant activity and the lowest toxic MRP formation.
... The seeds of the pods are used to obtain the locust bean gum and the kibbles are quite rich in sugars, around 50% weight basis. The aqueous extracts have bioactive compounds (Klenow et al., 2009). There are different valuable compounds, like d-pinitol, of pharmacological interest; polyphenols also constitute a source of compounds which have potential health benefits for humans. ...
... Fruits and leaves of carob tree contain proteins and phenolic compounds, and exhibit antioxidant, antiproliferative and antimicrobial activities [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In a previous work Balaban [17] used common spectroscopic (Folin-Ciocalteu and Rhodanin assays) and chromatographic (GC-MS) methods to determine the chemical composition of methanol / water extracts of heartwood and sapwood of carob tree from Turkey. ...
Article
Methanol (ME) and hot water extracts (WE) of carob tree sapwood (Ceratonia siliqua L.) exhibited high antioxidant activity and were rich in phenolic compounds, with the main compounds identified by HPLC/DAD as gentisic acid and (-)-epicatechin. The ME displayed a high in vitro antitumor activity against human tumoural cell lines and reduced intracellular ROS production by HeLa cells after treatment with H2O2. (-)-Epicatechin was shown to contribute to the cytotoxic activity of the ME. This is the first report on the biological activity of carob tree sapwood.
... When rats were treated with carob the reduction of SOD, CAT and GPx activities was inhibited, which protected against factors of oxidative stress, in particular H 2 O 2 . The reduced activity of SOD, CAT and GPx could be due to enhanced lipid peroxidation or inactivation of the antioxidative enzymes (Klenow et al., 2009). The antioxidant activity caused by the presence of these compounds could have additional effects, sparing other antioxidants and protecting molecules from oxidative damage during digestion and preserving the intestinal epithelium from potential oxidative damage caused by dietary factors or bacterial metabolism (Goni and Serrano, 2005). ...
Conference Paper
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The present study was performed to investigate the effect of a daily supplementation of carob pods (Ceratonia siliqua L.,) on rumen fermentation and milk production of goats. Thirty two lactating does (weight ranged from 33–35 kg), aged 2-4 years old and from 2nd to 3th lactation season were randomly allocated into four similar groups (8 animals each). The animals were fed with isocaloric and isonitrogenous diets. Carob pods was daily supplemented at the rate of 0, 25, 50 or 100g /h/d. The lactating trial was extended for 75 days where goats were fed individually and fresh water was available at all time. Rumen fermentation parameters were monitored on three fistulated adult does. Results indicated that volatile fatty acids concentration, rumen volume, microbial protein synthesis and total bacteria counts were highest (P<0.05) with C50 group compared with other groups. While, ammonia-N concentration and protozoa count were lower (P<0.05) with C100 group compared with other groups. Milk production, protein and fat percentage were better (P<0.05) for C50 and C25 groups than those of C100 group. Supplementation of Carob pods at 50 g caused a marked (P<0.05) increase in the enzymatic antioxidant activity (SOD, CAT, GPx, and GSH) but had a significant decrease (P<0.05) in TBARS compared to control group. Thus, it could be concluded that daily supplement of 50 g carob pods could be reasonable amount for goats performance without any adverse effect.
... Carob pods' aqueous extracts have been evaluated for their anti-proliferative activity against hepatocellular carcinoma [82]. The authors explored the proliferation reduction of T1 mouse cell line caused by the two extracts via bromodeoxyuridine (BrdU) assay and estimated the half maximal inhibitory concentration (IC 50 The high presence of gallic acid in carob extract has been pointed out by Klenow et al. [32,83,84]. The authors hypothesized that the anti-proliferative effect in HT29 and LT97 human colon cancer cell lines may occur due to the high existence of gallic acid in its unconjugated form [32]. ...
Article
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The contribution of natural products to the drug-discovery pipeline has been remarkable since they have served as a rich source for drug development and discovery. Natural products have adapted, during the course of evolution, optimum chemical scaffolds against a wide variety of diseases, including cancer and diabetes. Advances in high-throughput screening assays, assisted by the continuous development on the instrumentation’s capabilities and omics, have resulted in charting a large chemical and biological space of drug-like compounds, originating from natural sources. Herein, we attempt to integrate the information on the chemical composition and the associated biological impact of carob fruit in regards to human health. The beneficial and health-promoting effects of carob along with the clinical trials and the drug formulations derived from carob’s natural components are presented in this review.
... In another study, the extract of the carob's leaves showed significant radical scavenging activity, and displayed a good capacity to inhibit the proliferation of HELA tumor cells in their cultures [8]. Furthermore it was found that the extract of the carob's leaves can modulate gene expression and protect colon adenoma cells from the genotoxic effect of H2O2 [16]. ...
Article
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Cyclophosphamide is one of the chemotherapeutics for cancer, which is used to treat several types of cancer, however this drug has severe side effects include kidney and liver complications in addition to its genotoxicity. Some studies reported that exposure to cyclophosphamide induces intracellular ROS formation, so it is probably that its toxicity is due to the oxidative stress. Because the pods of carob (Ceratonia siliqua) contain natural antioxidants, the protective activity of its aqueous alcoholic extract against the cyclophosphamide induced genotoxicity was studied in this work (in vivo) by using the bone marrow micronucleus assay. The oral administration of the extract alone did not cause any toxic effects on bone marrow in rats, while the extract was able to reduced the toxic effects of cyclophosphamide on the bone marrow. The extract could reduce significantly the decrease in the percentage of polychromatic erythrocytes (PCEs) (33.6%) and the formation of micronucleus (Mn) in both types of erythrocytes (111.55 MnPCEs and 24.19 MnNCEs in 1000 cells). The results of this study indicate that giving the extract of carob pods to patients before and during receiving cyclophosphamide may reduce the toxic effects of this drug.
... Keçiboynuzundan elde edilmiş ve polifenollerce zengin diyet lifinin, yüksek kolesterol seviyesine sahip insanlar üzerinde etkisin araştırıldığı klinik bir çalışmada, diyet lifi verilen grupta diyet lifi verilmeyen guruba göre toplam kolesterol ve LDL kolesterol seviyelerinde düşüş olduğu gözlemlenmiştir [18]. Keçiboynuzunun içerdiği diyet lifi sayesinde, kolon sağlığı ve kolondaki hücrelerin gelişimi üzerinde olumlu etkilere sahip olduğu bilinmektedir [19][20][21][22]. ...
Article
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Keçiboynuzu (Ceratonia siliqua L.) besleyici değeri yüksek bir meyvedir ve ekonomik olarak değer taşımaktadır. Türkiye’de ve dünyada keçiboynuzu meyvesi genellikle Akdeniz ikliminin hakim olduğu, Akdeniz’e kıyısı olan bölgelerde yetişmektedir. Bu meyveden çoğunlukla keçiboynuzu pekmezi, keçiboynuzu unu, gam (locust bean gum), diyet lifi ve biyoaktif bir bileşen olan D-pinitol üretilmektedir. Keçiboynuzu meyvesi ve pekmezi içerdiği %52-62 toplam şeker miktarı ile enerji içeriği yüksek gıdalardır. Bunun yanı sıra yüksek mineral madde içeriğine sahip olup, özellikle de potasyum (843-1215 mg/kg), kalsiyum (251-361 mg/kg), fosfor (85-681 mg/kg) ve magnezyum (63-326 mg/kg) açısından zengindir. 3944.7 mg/kg toplam fenolik madde içeren keçiboynuzu meyvesinin lif içeriği ise 258.3 g/kg’dır. Keçiboynuzu meyvesinin kardiyovasküler ve gastrointestinal hastalıklar üzerine olumlu etkilerinin olduğu saptanmıştır. Aynı zamanda, başta çağımızın hastalığı olan diyabet ve birçok çeşitli hastalığa karşı etkili olduğu bilinen D-pinitol üretiminde kullanılabilen doğal bir hammadde olması nedeniyle keçiboynuzu değerli, katma değeri yüksek bir meyvedir. Bu çalışmanın amacı, keçiboynuzu meyvesiyle ilgili bilgileri derleyerek, ileride yapılacak çalışmalara katkı sağlamaktır.
... They are more important in food industry and are a source of many products such as gum, sugar, and alcohol [11] and as a natural additive (E 410) [12]. The different parts of carob tree exerted diverse physiological functions [13][14][15][16][17][18][19][20]. ...
Article
Carob tree, Ceratonia siliqua L., is a medicinal plant used in Tunisian traditional medicine for the treatment of the gastro-intestinal (GI) disorders. In this respect, a relatively large number of scientific publications on the carob tree have been published in recent years. Therefore, the present review was aimed to analyze the traditional uses, phytochemical constituents and pharmacological activities of Ceratonia siliqua on the GI tract. Indeed, previous investigations on the carob pods and leaves have revealed the presence of a number of compounds including high amounts of carbohydrates, dietary fibers, minerals, polyphenols, flavonoids and low amounts of protein and lipids. This plant possesses anti-inflammatory, antimicrobial, anti-diarrheique, antioxidant, anti-ulcer, anti-constipation and anti-absorptive of glucose activities in the gastrointestinal tract. Based on the chemical and pharmacological characteristics of C. siliqua, we concluded that this species has beneficial preventive and therapeutic properties, especially, in digestive tract.
... Carob fruits have been widely used in food, pharmaceutical and cosmetic industries. The most reported health benefits of carob are cholesterol lowering effects (Ruiz-Roso, Quintela, de la Fuente, Haya, & Pérez-Olleros, 2010), blood glucose level regulations (Bañuls et al., 2016;Gruendel et al., 2007), antimicrobial effects and high antioxidant potentials (Gruendel et al., 2006;Klenow, Jahns, Pool-Zobel, & Glei, 2009;Kumazawa et al., 2002). Also, other few studies have reported in vitro anticancer and anti-proliferative effects on mouse hepatocellular carcinoma (Corsi et al., 2002), HT29 colon adenocarcinoma cells and LT97 colon adenoma cells (Klenow, Glei, Haber, Owen, & Pool-Zobel, 2008). ...
Article
Carob is a well-known tree for its nutritional and health-promoting edible pods due to its high phenolic contents. It was aimed to investigate: 1) carob phenolic profiles; soluble free, soluble conjugated and bound, 2) bioaccesibility of those phenolics during simulated gastrointestinal digestions, plus in vitro fecal fermentations, 3) their antioxidant properties, also 4) α-amylase and α-glucosidase inhibitory activities. Ten phenolic acids and six flavonoids were detected in soluble (free and conjugated) and insoluble fractions of undigested carob. After in vitro gastrointestinal digestions, the most bioaccessible phenolic acids and flavonoids were gallic acid (647.4%), chlorogenic acid (485.4%), (+)-catechin (558.3%) and rutin (267.2%). Myricetin (79.5%) and gallic acid (20.0%) were the most abundant metabolites of residual fraction of carob phenolics after fecal fermentations. Antioxidant capacity of digested carob has increased significantly (p < 0.05); DPPH (107 mg GAE/g), ABTS (399 mg TE/g) and ORAC (415 μmol TE/g). Both undigested carob and its digested fractions showed a positive dose-dependent inhibition of α-amylase activity (0.3–1.0 mg/mL). The findings from this study showed first time report on carob phenolic profiles (soluble and insoluble) and their bioaccessibility during digestions and fecal fermentations. Carob phenolic might influence glucose metabolism by inhibiting carbohydrate digestion.
... It has a good antioxidant activity [9]. Such activity plays important role in lower the rate of lipid oxidation in life organisms and modulates their blood lipid profile [37]. ...
... On one hand, the n-hexane, methanol, ethanol, ethyl acetate and water extracts of carob leaves have shown antimicrobial effects on many microorganisms including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella thyphimurium, Enterobacter cloacae, Enterococcus faecalis, Pseudomonas aeroginosa and Candida albicans, and on another hand, these extracts demonstrated cytotoxic effect aganist brine shrimp [18]. Klenow et al. (2009) [19] have revealed that carob extracts are capable to prevent the oxidative stress, especially in human colon. The carob pod has displayed gastroprotective effect due to its strong antioxidant activity [20]. ...
Conference Paper
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Metabolomics, can be defined as little molecule -omics. Nowadays, the elucidation of the molecular mechanism of any disease with genome analysis and proteome analysis is not sufficient. Instead of these, a holistic assessment including metabolomic studies provides rational and accurate results. The application of metabolomics includes the identification of biomarkers, enzyme-substract interactions, drug-activity studies, metabolic pathway analysis and some other studies related with the system biology. Metabolomics is the cheap and correct separation, definition and measurement of all metabolites in cells, tissues or biological fluids in short amounts of time with high throughput technologies such as NMR, GC-MS and LC-MS. It is the quantitative measurement of the metabolic profile of the living being to characterize the genetics and the phenotypic response to nutritional status of it. Data comprehensive approach with the ability to collect high volume quantities, aims to improve our understanding of health and disease, nutrition and food role. The aim of this review; is to emphasize some potential applications of metabolomics in food and nutrition research, to investigate the effects of metabolomics on nutrition and to present scientific literature on these subjects. Keywords : Metabolomics, food, nutrition
... On one hand, the n-hexane, methanol, ethanol, ethyl acetate and water extracts of carob leaves have shown antimicrobial effects on many microorganisms including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella thyphimurium, Enterobacter cloacae, Enterococcus faecalis, Pseudomonas aeroginosa and Candida albicans, and on another hand, these extracts demonstrated cytotoxic effect aganist brine shrimp [18]. Klenow et al. (2009) [19] have revealed that carob extracts are capable to prevent the oxidative stress, especially in human colon. The carob pod has displayed gastroprotective effect due to its strong antioxidant activity [20]. ...
Book
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All rights reserved. No part of this publication can not be reproduced, distributed, or transmitted in any form including photocopying, recording, other electronic or mechanical methods, without the prior written permission of the publisher. 4 CONTENTS
... In the literature, there is no data on the protective effects of Cspe against 1,4-dioxane toxicity, but similar properties against different oxidative agents have been investigated. Klenow et al. (2009) reported that C. siliqua extract has protective properties against oxidative damage, in particular against the harmful effects of hydrogen peroxide. ...
Article
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In this study, the toxic effects of 1,4-dioxane, a common contaminant, and the protective property of Ceratonia siliqua L. pod extract (Cspe) against this toxicity are aimed to be demonstrated with a versatile model. For this purpose, Allium toxicity test was used and six different experimental groups were formed. While the control group was germinated in tap water, the application groups were germinated in mediums containing 750 mg/L Cspe, 1500 mg/L Cspe, 100 mg/L 1,4-dioxane, 750 mg/L Cspe+100 mg/L 1,4-dioxane, and 1500 mg/L Cspe+100 mg/L 1,4-dioxane. Each group was germinated in related solution for 72 h and alterations in physiological, biochemical, genetic, and anatomical parameters were investigated. Germination percentage, relative injury rate, root length, and weight gain parameters were examined as physiological parameters, and no significant difference was observed in the control group and only-Cspe-treated groups. In groups treated with 100 mg/L 1,4-dioxane, germination percentage, root length, and weight gain were significantly decreased, and the relative injury rate reached the highest value as 0.48. It was determined that all physiological parameters improved in the groups where Cspe and 1,4-dioxane treated together, and the relative injury rate decreased to 0.22 in the group treated with 1500 mg/L Cspe+1,4-dioxane. Genotoxic effects were tested by the micronucleus and chromosomal abnormality frequency, and statistically insignificant micronucleus formation was found in control group and Cspe-treated groups. Micronucleus frequency were found to be 58.00 ± 12.12 and 31.00 ± 07.38 in 1,4-dioxane and 1500 mg/L Cspe+1,4-dioxane-treated groups, respectively. This result showed that the application of 1500 mg/L Cspe had a 46.5% reduction in the frequency of 1,4-dioxane-induced micronucleus and had a protective effect on genomic integrity. It has been found that 1,4-dioxane application induces lipid peroxidation and increases malondialdehyde level 4.5 times compared with control group. Oxidative stress, which was proved by increased malondialdehyde levels in 1,4-dioxane-treated group caused induction of superoxide dismutase and catalase enzymes, and it was determined that enzyme activities increased by 1.99 and 4.9 times, respectively, compared with the control group. Cspe treatment with 1,4-dioxane caused a significant decrease in malondialdehyde level, superoxide dismutase, and catalase enzyme activities, indicating that oxidative stress formation in the cells was repressed. Abnormalities such as cell deformation, cell wall thickening, and flattened cell nuclei were seen in 1,4-dioxane-treated group in the cross sections of root tips, and the frequency of these abnormalities decreased with Cspe application. As a result, it was determined that 1,4-dioxane caused a versatile toxicity in the test material Allium cepa, whereas Cspe application had a dose-dependent protective feature against toxicity in all tested parameters.
... On one hand, the n-hexane, methanol, ethanol, ethyl acetate and water extracts of carob leaves have shown antimicrobial effects on many microorganisms including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella thyphimurium, Enterobacter cloacae, Enterococcus faecalis, Pseudomonas aeroginosa and Candida albicans, and on another hand, these extracts demonstrated cytotoxic effect aganist brine shrimp [18]. Klenow et al. (2009) [19] have revealed that carob extracts are capable to prevent the oxidative stress, especially in human colon. The carob pod has displayed gastroprotective effect due to its strong antioxidant activity [20]. ...
Book
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Botanical origin and antibacterial activity of Hedysarum coronarium and Citrus honey against Pseudomonas aeroginosae, Staphylococcus aureus and Klebsiella pneumonia Messaouda BELAID *1, Arezki MOHAMMEDI 1, Salima KEBBOUCHE-GANA 1, Fatma ACHEUK 1,Nora CHAHBAR 1 AND Malika ABBAD-BENNOUR 2 1. Laboratory of Valorisation and conservation of biological resources (VALCOR). Faculty of Sciences, University M’Hamed Bougara of Boumerdes, Algeria 2. Faculty of Biological and Agricultural Sciences Mouloud Mammeri of Tizi Ouzou, Algeria *Corresponding author: belaidfo@yahoo.fr ABSTRACT Honey has always been regarded as a food which is advantageous for one’s health and as a product which has healing qualities. The purpose of the study was to evaluate the antibacterial activity of Hedysarum coronarium and Citrus honey against Pseudomonas aeroginosae, Staphylococcus aureus and Klebsiella pneumonia. To test the antibacterial activity, the agar well diffusion methods was employed. For the palynological analysis, we used the methodology proposed by Louveaux et al (1978); a minimum of 1200 pollen grains was counted par sample. Commonly, monofloral honeys were made up of nectar belonging to a single plant in an extent of at least 45%. These were general guidelines but many pollen types were under represented (such Citrus honey) or over represented (for example Eucalyptus honey). The results showed that the Citrus honey exhibited the highest inhibition against Klebsiella pneumonia and Pseudomonas aeroginosae comparatively of the Hedysarum coronarium honey. Keywords: Hedysarum coronarium Honey, Citrus honey, pollen analysis, antibacterial activity
... The search for drugs from natural sources that can exhibit a chemopreventive or cytotoxic effect is on the rise (Amessis-Ouchemoukh et al. 2017;Custódio et al. 2009Custódio et al. , 2011aKlenow et al. 2009;Roseiro et al. 2013b). Furthermore, carob preparations rich in pods fibers hold an European patent registered as anti-inflammatory products and chemopreventive agents (Haber 2003 ...
Chapter
Ceratonia siliqua (Carob); is a Mediterranean legume globally recognized for its commercial value, being used as a cold beverage, in bakery and confectionary products. It is widely used as a Cocoa substitute not only due to its richness in sugar but rather the absence of caffeine and theobromine stimulant action. Both fruit pulp and seeds are of potential nutritive and medicinal values. The pulp comprises a high sugar content dominantly sucrose as well as polyphenols viz. phenolic acids, flavonoids and tannins. Seeds potential usage is attributed to its locust bean gum (LBG), commercially and pharmaceutically used as gelling and stiffening agent. Carob syrup is a traditional product native to the Mediterranean region, enriched in D-pinitol sugar of anti-diabetic effect. Considering the diversity of carob active constituents’ classes, a myriad of biological effects is recorded to include antioxidant, anticancer, antimicrobial and anti-hyperlipidemic effects. This book chapter presents up to date information on carob usage and chemistry while providing insight on research questions or applications yet to be addressed.
... To conclude this part, it is important to pay attention to two additional reports. First, S. Klenow and her colleagues, 194 raised the question: does an extract of Carob have chemopreventive potential related to oxidative stress? And after a fundamental research they conclude that the answer is not clearly "yes". ...
... Accumulating evidence from epidemiological studies as well as laboratory data suggest 69 that consumption of fruits and vegetables is associated with a reduced risk of 70 developing a wide range of cancers including colon cancer [5,6]. Dietary strategies for 71 cancer prevention are considered attractive alternatives because the consumption of 72 natural compounds with potential chemopreventive effects is associated with low 73 toxicity, safety and good acceptance by the public [7,8] ...
Article
Consumption of fruits and vegetables is associated with a reduced risk of developing a wide range of cancers including colon cancer. In this study, we evaluated the effects of two compounds present in fruits and vegetables, ursolic acid, a triterpenoid, and luteolin, a flavonoid, on DNA protection and DNA repair in Caco-2 cells using the comet assay. Ursolic acid and luteolin showed a protective effect against H(2)O(2)-induced DNA damage. Repair rate (rejoining of strand breaks) after treatment with H(2)O(2) was increased by pre-treatment of Caco-2 cells for 24h with ursolic acid or luteolin. To evaluate effects on induction of base oxidation, we exposed cells to the photosensitizer Ro 19-8022 plus visible light to induce 8-oxoguanine. Luteolin protected against this damage in Caco-2 cells after a short period of incubation. We also measured the incision activity of a cell extract from Caco-2 cells treated for 24h with test compounds, on a DNA substrate containing specific damage (8-oxoGua), to evaluate effects on base excision repair activity. Preincubation for 24h with ursolic acid enhanced incision activity in Caco-2 cells. In conclusion, we demonstrated for the first time that ursolic acid and luteolin not only protect DNA from oxidative damage but also increase repair activity in Caco-2 cells. These effects of ursolic acid and luteolin may contribute to their anti-carcinogenic effects.
... Carob pods contain small amounts of proteins (3-4%) and lipids (0.4-0.8%) and significant amounts of carbohydrates (76%), mainly soluble ones, such as sucrose [4]. Carob is rich in polyphenols, especially in condensed tannins [5] and gallic acid, which is responsible for gene expression modulating and protecting of colon adenoma cells from the genotoxic impact of H 2 O 2 [6] . In the food industry it is mostly used for gum (carob gum, locust bean gum) production because of galactomannans contained in the endosperm of the seeds. ...
Article
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The increasing demand for cocoa and search for ingredients rich in bioactive compounds encouraged us to investigate the possibility of replacing it by carob powder in the muffins containing soy beans, sesame oil and flaxseeds. There was 5% addition of carob or cocoa powder to the individual doughs. The muffins with the addition of carob were characterized by improved antiradical activity (by 36% - 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) method, by 83% - 2,2-diphenyl-1-picrylhydrazyl (DPPH) method), higher content of genistein (18%) and total phytosterols (17%) in the dry mass. The color differences in the carob muffins crusts were not perceptible by consumers (ΔE = 0.70 for crust, ΔE = 5.6 for crumb) and their taste was found to be less bitter and sweeter than the taste of cocoa muffins. Moreover, the addition of carob powder as well as cocoa powder resulted in good sensory quality. The high content of phytosterols, genistein and improved antiradical properties proved carob to be a source of bioactive compounds. The results show that carob powder may be used as valuable alternative muffin ingredient to cocoa. Electronic supplementary material The online version of this article (10.1007/s11130-018-0675-0) contains supplementary material, which is available to authorized users.
... Reduction in cell viability was also observed in breast and prostate cancer cells [33]. Moreover, carob aqueous polyphenolic extracts inhibited cell proliferation and reduced colon carcinoma and colon adenoma cells [187,188]. Same results observed for carob fiber extract [189]. Carob fiber is suggested as chemopreventive agent and chewable tablets and fruit bars rich in carob fiber have been marketed [190]. ...
Article
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Cocoa originates from the beans of the cocoa tree (Theobroma cacao L.). It is an important commodity and the main ingredient in chocolate manufacture. Its value and quality are related to complex flavors and to its distinct sensory properties. The increasing demand for cocoa and its rising price urges the research for cocoa substitutes. A potential substitute for cocoa is carob. Carob is the fruit of an evergreen tree (Ceratonia siliqua L.) cultivated in the Mediterranean area, well known for its valuable locust bean gum and also for carob powder and syrup that are obtained from carob pulp. Cocoa beans and carob pods contain various phytochemicals including polyphenols, proteins and amino acids, fatty acids, carbohydrates and fiber. Phytochemicals represent an important source of nutrients and compounds that are beneficial to human health. In this review, phytochemicals in cocoa beans and carob pods and their impact on human health are reviewed. The bioactive compounds that are present in carob, in conjunction with the cocoa-like flavors and unique sensory properties that are enhanced by carob powder roasting, underline carob’s potential to substitute cocoa in various food products. These food applications are discussed in this review.
Article
Ethnopharmacological relevance: Given the severe side effects associated with most of the conventional cancer medications, as well as the expanding body of evidence indicating secondary toxicity of these drugs, individuals with cancer are increasingly turning to natural alternatives. Similarly, the pharmaceutical industry is in search of natural products to treat cancer. An understanding of the specific active components in plant products with which anti-cancer efficacy is achieved is required for this research to move forward. Aim of the study: To integrate data from cancer-related studies on plant-derived products or extracts, to elucidate whether these products may have similar active ingredients and/or mechanisms of action, that can explain their efficacy. This review also includes a discussion of the methodological complexities and important considerations involved in accurate isolation and characterisation of active substances from plant material. Conclusions: From the literature reviewed, most plant products with consistently reported anti-cancer efficacy contains high levels of polyphenols or other potent antioxidants and their mechanisms of action correlate to that reported for isolated antioxidants in the context of cancer. This suggests that natural products may indeed become the panacea against this chronic disease - either as therapeutic medicine strategy or to serve as templates for the design of novel synthetic drugs. The recommendation is made that antioxidant activity of plant actives and especially polyphenols, should be the focus of anti-cancer drug discovery initiatives. Lastly, researchers are advised to exploit current techniques of chemical compound characterization when investigating polyphenol-rich plants to enable the easy consolidation of research findings from different laboratories.
Thesis
Le caroubier est considéré comme l'un des arbres fruitiers et forestiers qui présente le plus grand potentiel de valorisation puisque toutes les parties de cette plante sont utilisables dans plusieurs applications industriels. Le caroubier est cultivé dans plusieurs régions du Liban mais peu d'études sont disponibles sur les voies de valorisation et sur les propriétés fonctionnelles et structurales des graines et des gousses. Ainsi, dans le cadre d'une démarche qui vise à promouvoir et contribuer à une meilleure valorisation et gestion de cette ressource renouvelable, nous avons entrepris dans cette thèse des travaux consacrés à la caractérisation et à l'évaluation de la valeur nutritive et fonctionnelle des gousses de caroube issues de plusieurs régions libanaise. Ces travaux ont porté notamment sur la caractérisation morphologique et physico-chimique des gousses et sur la purification des gommes extraits des graines. Ces gommes ont fait l'objet d'une étude approfondie portant sur leur comportement rhéologique et la relation entre ce comportement, la variété et le lieu géographique. Nous avons aussi déterminé les isothermes de sorption de ces gommes pour prédire les conditions idéales de leur conservation. Les résultats obtenus à l'issue de cette étude ont démontré clairement la présence des corrélations morphologie, composition chimique et coordonnées géographiques de différents cultivars étudiés. De même, les études structurales et rhéologiques ont montré des différences significatives entre les gommes purifiées. Cette différence semble être liée à une variation du rapport galactose/mannose et de la masse molaire observée selon les variétés. Par ailleurs, les études des isothermes de sorption ont permis de fournir des informations complémentaires sur leurs hygroscopicités et par conséquence sur les conditions idéales de leur conservation
Research
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Onwasigwe, Ebubechukwu, Ph.D., Alabama A&M University, 2016. 179 pp. Dissertation Advisor: Dr. Martha Verghese, Ph.D. Allspice contains phytochemicals which may have antioxidative and chemopreventive potential. The objective of this study was to determine the antioxidant potential of allspice, possible different in vivo chemopreventive mechanisms of action and in vivo chemopreventive effects on colon cancer in Fisher 344 male rats. Total phenolic and flavonoid contents, and antioxidant activity of both aqueous and methanolic extracts of allspice was conducted using different colorimetric assays (DPPH, TEAC, and FRAP). In the animal study, rats in experimental groups were fed with different concentrations of allspice (0.5%, 1% and 2%) in an AIN-93G based diet. Rats received AOM injections at 7 and 8 weeks of age at 24mg/kg body weight. After 17 weeks, rats were asphyxiated with CO2, and liver, colon and cecum samples were collected. Colons stained with methylene blue and ACFs were enumerated and crypt multiplicity was determined. Total phenolic content in both methanol and water extracts were 728.4±137.5 GAE/g and 678.3±141.1 GAE/g. Total flavonoid content in methanol and water extracts were 595.31±51.77mgCE/100g and 255.99±9.89mgCE/100g. The IC50 (DPPH assay) concentration for water and methanol extracts was 21.5mg/ml and PREVIEW vi 22mg/ml. FRAP assay showed similar results for methanol and water extractions (4.5±0.03 and 5.07±0.1 mmol Fe/g). Results for ABTS scavenging ability for methanol and water extracts was 355.8±9.7mmolTE/100g and 362.4±7.2mmolTE/100g. Rats fed 0.5% allspice had the highest pH (7.64) compared to control (6.88). Rats in the treatment groups gained 251g (0.5%), 242g (1%), and 225g (2%) over the 13week period. There was a 29% reduction in total crypts in rats fed 0.5% compared to 2% allspice. Highest number of crypts was seen in control group (777), and the reduction of crypts compared to control in 0.5, 1, and 2% treatments were 30.8%, 30.75% and 78%, respectively. Rats fed 0.5% allspice had higher ACF counts compared to those fed 1% allspice. Total ACF and crypts in rats fed 2% allspice were lower compared to those fed 0.5% allspice. This study reveals that consumption of allspice in the diet reduced the number of ACF in Fisher 344 male rats. Allspice may show beneficial effects in the prevention of chronic diseases due to its antioxidant activity. Utilization of allspice in food products may provide additional functional properties.
Article
The objective of this study was to evaluate carob pods and their effect on growth performance, antioxidant activities, carcass and caecal characteristics and equilibrium modification of the caecal microbiota population of growing NZW rabbits. Eighty weaned rabbits (initial body weight: 625.00 ± 26.46 g) were randomly allocated into four dietary groups of 20 rabbits each until 90 days of age. Dietary groups were as follows: C (basal diet with no supplementation), CP1 (basal diet + 2.5% carob pods), CP2 (basal diet + 5% carob pods) and CP3 (basal diet + 10% carob pods). Rabbits given the CP2 diet had significantly higher daily and final body weights compared with the other experimental groups. The increase in inclusion rate of carob pods significantly decreased feed intake, whereas carob pods at 5% in the CP2 group recorded the best value of feed conversion ratio. Rabbits in the CP3 group showed the worst slaughter weight and carcass dressing percentage weight. No significant effect was found on meat protein and ash contents. Cholesterol, low-density lipoprotein, high-density lipoprotein and triglycerides decreased significantly (p < 0.05) in rabbits treated with carob pods compared with the control. Because of high content of the antioxidant compounds in CP2 and CP3 groups, the activities of glutathione peroxidase, glutathione S-transferase, catalase and superoxide dismutase increased, whereas the concentration of thiobarbituric acid-reactive substance decreased significantly. Rabbits given the CP2 diet had a significantly higher volatile fatty acid concentration and a lower pH in content of the caecum compared to the other groups. The data of microbial analysis for C group showed a significant increase in Escherichia coli and Clostridium counts. Lactobacillus and Bacillus counts increased significantly more in the CP2 and CP3 groups than in the other groups. In conclusion, 5% of carob pods in the diet stimulated the performance of growing rabbits, and thus, it has potential as an unconventional feed resource for rabbits without any adverse effects.
Article
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The application of DNA microarray assay (DMA) has entered a new era owing to recent innovations in omics technologies. This review summarizes recent applications of DMA-based gene expression profiling by focusing on the screening and characterization of traditional Chinese medicine. First, herbs, mushrooms, and dietary plants analyzed by DMA along with their effective components and their biological/physiological effects are summarized and discussed by examining their comprehensive list and a list of representative effective chemicals. Second, the mechanisms of action of traditional Chinese medicine are summarized by examining the genes and pathways responsible for the action, the cell functions involved in the action, and the activities found by DMA (silent estrogens). Third, applications of DMA for traditional Chinese medicine are discussed by examining reported examples and new protocols for its use in quality control. Further innovations in the signaling pathway-based evaluation of beneficial effects and the assessment of potential risks of traditional Chinese medicine are expected, just as are observed in other closely related fields, such as the therapeutic, environmental, nutritional, and pharmacological fields.
Article
Ceratonia siliqua is a typical Mediterranean plant, mainly used in food and Tunisian traditional folk medicine. Among the tested extracts, the ethyl acetate fraction (EACs) exhibited the highest total phenolic and flavonoids content. The antioxidant activity in vitro systems showed a more significant potent free radical scavenging activity of this extract than other analysis fractions. The HPLC finger print of EACs active extract showed the presence of six phenolic compounds. The in vivo results showed that oral administration of CCl(4) enhanced levels of hepatic and renal markers (ALT, AST, ALP, LDH, γ-GT, urea and creatinine) in the serum of experimental animals. It also increased the oxidative stress markers resulting in increased levels of the lipid peroxidation with a concomitant decrease in the levels of enzymatic antioxidants (SOD, CAT, GPx) in both liver and kidney. The pre-treatment of experimental rats with 250 mg/kg (BW) of the EACs, by intraperitoneal injection for 8 days, prevented CCl(4) induced disorders in the levels of hepatic and kidney markers. The biochemical changes were in accordance with histopathological observations suggesting a marked hepatoprotective and nephroprotective effect of the EACs extract.
Article
Extracts from fruit pulps of six female cultivars and two hermaphrodite Portuguese carob trees [(Ceratonia siliqua L., Fabaceae)] exhibited strong antioxidant activity and were rich in phenolic compounds. The extracts decreased the viability of different human cancer cell lines on a dose- and time-dependent manner. Gender and cultivar significantly influenced the chemical content and the biological activities of the extracts. Extracts from hermaphrodite trees had a higher content of phenolic compounds, and exhibited higher antioxidant and cytotoxic activities. Among females, cv. Aida had the highest radical scavenging activity and total content of phenolics, Mulata the highest capacity to inhibit lipid oxidation and Gasparinha the strongest cytotoxic activity on HeLa cells. The decrease in cell viability was associated with apoptosis on HeLa and MDA-MB-231 lines. (+)-Catechin and gallic acid (GA) were the main compounds identified in the extracts, and GA contributed to the antioxidant activity. Our results show that the antioxidant and cytotoxic activities of carob tree fruit pulps are strongly influenced by gender and cultivar, and provide new knowledge about the advantages of hermaphrodite trees over female cultivars, namely, as a source of compounds with biological interest, which may represent an increase of their agronomic interest.
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Actualment hi ha un especial interès pels compostos fenòlics dels aliments en àmbits de la nutrició,salut i medicina en base a diferents evidències que suggereixen que poden actuar com a potentsantioxidants i/o moduladors de funcions biològiques claus en els mamífers. Paral·lelament, hi hauna demanda per part dels consumidors en quant a la informació dels aliments que singereix, deles necessitats nutricionals així com de la millora de salut. Tots aquest conceptes juntament amb ladefinició imminent de la legislació europea en relació als perfils nutricionals i les al·legacions depropietat de salut porta implícit la disponibilitat de metodologies adequades per a la caracteritzaciódels aliments. Per a donar resposta a una necessitat actual, linterès daquesta tesis es centra en eldesenvolupament de metodologies que permetin la identificació, verificació, quantificació i eficiènciade compostos bioactius. Aquestes metodologies representen eines de treball que han de facilitar laformulació de nous aliments amb al·legacions de propietat de salut.Per assolir aquests objectius, aquest treball va seleccionar dues fonts dorigen vegetal per alobtenció i avaluació de compostos fenòlics: el cacau i la garrofa. Els extractes de cacau són unafont reconeguda de compostos fenòlics, principalment procianidines, i alcaloides. En el presentestudi linterès es centra bàsicament en ampliar la seva caracterització fenòlica, avaluar la sevacapacitat antioxidant i lefecte del processament tecnològic. Per assolir aquesta fita es va treballaramb diversos productes derivats del processament del cacau, sent aquests la fava, el nib, el licorde cacau i el pols de cacau.Lacceptació dels productes elaborats amb el cacau és universal i darrerament shan publicatestudis que confirmen que els fenols presents en la xocolata, procedents del cacau, resultenbeneficiosos per a la salut. Tot i això, lalt contingut en greixos saturats, així com la riquesa ensucres són factors limitadors alhora daconsellar un increment del consum en una dieta equilibrada.Per aquest motiu es va proposar com a font alternativa la farina de garrofa, per a presentar uncontingut baix de greixos i ser una font rica de fibra.El fruit daquest treball es recull en el desenvolupament de tècniques cromatogràfiques quepermeten identificar i quantificar el perfil fenòlic dels derivats del cacau i de la farina de garrofa(UPLC-MS/MS) així com tècniques espectrofotomètriques que es poden emprar com a einesràpides de selecció dextractes polifenòlics (Folin-Ciocalteau i lassaig de Vainillina). Al mateixtemps, shan optimitzat dues metodologies dextracció que han permès lobtenció dextractes rics encompostos fenòlics dambdues fonts destudi. Els extractes polifenòlics obtinguts han estat avaluatsen termes de la capacitat antioxidant a nivell in-vitro aplicant el mètode DPPH i posant a punt iaplicant el mètode ORAC. Finalment, sha avaluat lestabilitat dels compostos fenòlics de lesmatrius destudi sota condicions fisiològiques del procés de digestió humana mitjançant eldesenvolupament dun model de digestió gastrointestinal in-vitro.ResumenEn la actualidad hay un especial interés por los compuestos fenólicos de los alimentos en losámbitos de la nutrición, la salud y la medicina preventiva, basado en diferentes evidencias queindican que los compuestos fenólicos pueden actuar como potentes antioxidantes y/o moduladoresde funciones biológicas claves en los mamíferos. Paralelamente, hay una demanda por parte delos consumidores de información acerca de los alimentos que se consumen y de las necesidadesnutricionales, así como de la mejora de la salud. Todos estos conceptos, junto con la definicióninminente de la legislación europea en relación a los perfiles nutricionales y a las alegaciones depropiedades saludables, lleva implícito la necesidad de disponer de metodologías adecuadas parala caracterización de los alimentos, especialmente para determinar su contenido en componentesminoritarios bioactivos. Para contribuir a dar respuesta a esta necesidad actual, la tesis tiene porobjetivo el desarrollo de metodologías que permitan la identificación, verificación, cuantificación yeficiencia de compuestos bioactivos, concretamente de los compuestos fenólicos. Estasmetodologías serán herramientas de trabajo de gran utilidad para facilitar la formulación de nuevosalimentos con alegaciones de propiedades saludables.El trabajo se ha centrado en la obtención y evaluación de compuestos fenólicos de dos fuentes deorigen vegetal, el cacao y la algarroba. Los extractos de cacao son una fuente reconocida decompuestos fenólicos, principalmente de procianidinas, y alcaloides. La aceptación de losproductos elaborados a partir del cacao es universal y durante los últimos años son numerosos losestudios que confirman que los fenoles presentes en el chocolate, procedentes del cacao, tienenefectos beneficiosos para la salud. Sin embargo, el alto contenido en grasas saturadas, así comola riqueza en azúcares son factores limitadores para el consumo de chocolate en el contexto deuna dieta equilibrada. Por este motivo se propuso el estudio de una fuente alternativa, la harina dealgarroba, al presentar un contenido bajo de grasa y ser una fuente rica de fibra. El estudio sedirige básicamente hacia la ampliación de las herramientas para la caracterización de la fracciónfenólica, y para evaluar tanto la capacidad antioxidante como el efecto del procesamientotecnológico sobre los compuestos fenólicos. Para alcanzar este último hito se trabajó con diversosproductos derivados del procesamiento del cacao, concretamente el haba de cacao, el nib, el licorde cacao y el polvo de cacao.Los resultados de este trabajo comprenden el desarrollo de técnicas cromatográficas que permitenidentificar y cuantificar el perfil fenólico de los derivados del cacao y de la harina de algarroba(UPLC-MS/MS), así como técnicas espectrofotométricas que se presentan como herramientasrápidas de selección de extractos fenólicos (Folin-Ciocalteau y el ensayo de Vainillina). Al mismotiempo, se ha optimizado dos metodologías de extracción que han permitido la obtención deextractos ricos en compuestos fenólicos a partir de ambas fuentes de estudio. Los extractospolifenólicos obtenidos han sido evaluados en términos de la capacidad antioxidante a nivel in-vitroaplicando el método DPPH y poniendo a punto y aplicando el método ORAC. Finalmente, se haevaluado la estabilidad de los compuestos fenólicos de las matrices de estudio en medios quesimulan las condiciones fisiológicas del proceso de digestión humana, para lo que se ha desarrollode un modelo de digestión gastrointestinal in-vitro. Los resultados han mostrado un claro efecto dela composición de la matriz alimentaria sobre la estabilidad de los compuestos fenólicos durante elproceso de digestión. Estos resultados serán de gran utilidad en la formulación de nuevosalimentos con alegaciones de propiedades saludables.AbstractNowadays, there has been a growing interest in polyphenols because of their physiological healthbenefits, including antioxidant activity in the areas of nutrition, health and medicine. In parallel,there is increasing consumer demand for food information concerning nutritional needs as well asthe improvement of health. All these concepts, together with the imminent definition of theEuropean legislation in relation to the nutritional profiles and the allegations of health claims,involve the availability of suitable methodologies for food characterization. To respond to theserequirements, this thesis is focused on the development of methodologies that allow theidentification, verification and quantification of the bioactive compounds (polyphenols). Thesemethodologies are presented as tools of work, which have to facilitate the formulation of new foodswith alleged health benefits.In order to reach these aims, this work selected two vegetable-origin sources to obtain andevaluate phenolic extracts: cocoa and carob. It is well-known that the polyphenol content of cocoabeans is mainly procyanidins, and alkaloids; however, this can vary greatly between differentvarieties and origins of the beans and also through the manufacturing processes. This work wasfocused on the evaluation of the cocoa bean and its by-products (nib, liquor and cocoa powder) asa potential source of bioactive compounds (polyphenols), which can be used as ingredients in thefood and chocolate industry. The products elaborated from cocoa are universally accepted. Inaddition, different studies have shown recently that the consumption of cocoa and its products havepositive and varied health effects. However, cocoa products contain high levels of saturated fattyacids and sugar, which limit the increase in their consumption in a balanced diet. For thesereasons, carob flour was proposed as an alternative source with a marked nutritional value due toits high levels of dietary fiber and phenol compounds.The results of this work are the development of several chromatographic techniques, which allowthe phenolic profile of cocoa derivatives and carob flour (UPLC-MS/MS) to be defined andquantified. In addition, several spectrophotometrical techniques are proved as fast tools formonitoring the phenol yield efficiency of the obtained extracts (Folin-Ciocalteau and the Vainillinassay). Also, two optimized extraction methodologies have allowed phenol-rich extracts to beobtained from cocoa and carob. The phenol extracts obtained have been evaluated in terms of theirantioxidant capacity using in-vitro methods, such as DPPH and ORAC. Finally, the stability of thephenolic compounds in cocoa and carob samples has been studied under human physiologicaldigestion conditions through the development of an in-vitro gastrointestinal model.
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Abstract Polysaccharides in carob fruit, including carob bean gum (also known as carob gum, locust bean gum) and carob fiber, are widely used in industries such as food, pharmaceuticals, paper, textile, oil well drilling and cosmetics. Carob bean gum is a galactomannan obtained from the seed endosperm of carob tree and the fiber is obtained by removing most of soluble carbohydrates in carob pulp by water extraction. Both the gum and fiber are beneficial to health for many diseases such as diabetes, bowel movements, heart disease and colon cancer. This article reviewed the composition, properties, food applications and health benefits of polysaccharides from carob fruit.
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Gallic acid (GA), a food component that is especially abundant in tea, is an antimutagenic, anticarcinogenic and anti-inflammatory agent. We conducted a study using acidum gallicum tablets that contained 10% GA and 90% glucose and a black tea brew that contained 93% of its GA in free form to determine the pharmacokinetics and relative bioavailability of GA in healthy humans. After the administration of a single oral dose of acidum gallicum tablets or tea (each containing 0.3 mmol GA) to 10 volunteers, plasma and urine samples were collected over various time intervals. Concentrations of GA and its metabolite, 4-O-methylgallic acid (4OMGA), were determined, and the pharmacokinetic parameters were calculated. GA from both the tablets and tea was rapidly absorbed and eliminated with mean half-lives of 1.19 +/- 0.07 and 1.06 +/- 0.06 h and mean maximum concentrations of 1.83 +/- 0.16 and 2.09 +/- 0.22 micromol/L (plasma), respectively. After oral administration of the tablets and black tea, 36.4 +/- 4.5 and 39.6 +/- 5.1% of the GA dose were extracted in urine as GA and 4OMGA, respectively. The relative bioavailability of GA from tea compared with that from the tablets was 1.06 +/- 0.26, showing that GA is as available from drinking tea as it is from swallowing tablets of GA.
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Colon carcinogenesis is a multistep process where oxygen radicals were found to enhance carcinogenesis at all stages: initiation, promotion, and progression. Since insufficient capacity of protective antioxidant system can result in cancer, the aim of this study was to examine the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the levels of reduced glutathione, vitamin C, and vitamin E. The lipid peroxidation products were also determined by measuring malondialdehyde and 4-hydroxynonenal levels in colorectal cancer tissue collected from 55 patients. In these cases the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase was significantly increased while the activity of catalase was significantly decreased in cancer tissue. However, the level of nonenzymatic antioxidant parameters (glutathione, vitamin C, and vitamin E) was significantly decreased in cancer tissue. Further lipid peroxidation was enhanced during cancer development, manifested by a significant increase in malondialdehyde and 4-hydroxynonenal levels. The obtained results indicate significant changes in antioxidant capacity of colorectal cancer tissues, which lead to enhanced action of oxygen radicals, resulting in lipid peroxidation.
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Green tea, mainly through its constituents epigallocatechin gallate, epigallocatechin, epicatechin gallate and epicatechin, has demonstrated anticarcinogenic activity in several animal models, including those for skin, lung and gastro-intestinal tract cancer, although less is known about colorectal cancer. Quercetin, the major flavonoid present in vegetables and fruit, exerts potential anticarcinogenic effects in animal models and cell cultures, but less is known about quercetin glucosides. The objectives of this study were to investigate (i) the antioxidant activity of the phenolic compounds epicatechin, epigallocatechin gallate, gallic acid and quercetin-3-glucoside; (ii) the cytotoxicity of different concentrations of epicatechin, epigallocatechin gallate, and gallic acid; (iii) the cellular uptake of epicatechin, epigallocatechin gallate, gallic acid and quercetin-3-glucoside and (iv) their effect on the cell cycle. Human colon adenocarcinoma cells were used as experimental model. The results of this study indicate that all dietary flavonoids studied (epicatechin, epigallocatechin gallate, gallic acid and quercetin-3-glucoside) show a significant antioxidant effect in a chemical model system, but only epigallocatechin gallate or gallic acid are able to interfere with the cell cycle in Caco2 cell lines. These data suggest that the antioxidant activity of flavonoids is not related to the inhibition of cellular growth. From a structural point of view, the galloyl moiety appears to be required for both the antioxidant and the antiproliferative effects. British Journal of Cancer (2002) 86, 1645–1651. DOI: 10.1038/sj/bjc/6600295 www.bjcancer.com © 2002 Cancer Research UK
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Reactive oxygen species (ROS) can induce carcinogenesis via DNA injury. Both enzymatic and non-enzymatic parameters participate in cell protection against harmful influence of oxidative stress. The aim of the present study was to assess the levels of final lipid peroxidation products like malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE) in primary colorectal cancer. Moreover, we analysed the activity of main antioxidative enzymes, superoxide dismutase (Cu, Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSRG-R) and the level of non-enzymatic antioxidants (glutathione, vitamins C and E). Investigations were conducted in 81 primary colorectal cancers. As a control, the same amount of sample was collected from macroscopically unchanged colon regions of the most distant location to the cancer. Homogenisation of specimens provided 10% homogenates for our evaluations. Activity of antioxidant enzymes and level of glutathione were determined by spectrophotometry. HPLC revealed levels of vitamins C and E and served as a method to detect terminal products of lipid peroxidation in colorectal cancer. Our studies demonstrated a statistically significant increase in the level of lipid peroxidation products (MDA-Adc.muc.-2.65+/-0.48 nmol/g, Adc.G3-2.15+/-0.44 nmol/g, clinical IV stage 4.04+/-0.47 nmol/g, P<0.001 and 4-HNE-Adc.muc. -0.44+/-0.07 nmol/g, Adc.G3-0.44+/-0.10 nmol/g, clinical IV stage 0.52+/-0.11 nmol/g, P<0.001) as well as increase of Cu,Zn-SOD (Adc.muc.-363+/-72 U/g, Adc.G3-318+/-48 U/g, clinical IV stage 421+/-58 U/g, P<0.001), GSH-Px (Adc.muc. -2143+/-623 U/g, Adc.G3-2005+/-591 U/g, clinical IV stage 2467+/-368 U/g, P<0.001) and GSSG-R (Adc.muc.-880+/-194 U/g, Adc.G3-795+/-228 U/g, clinical IV stage 951+/-243 U/g, P<0.001) in primary tumour comparison with normal colon (MDA-1.39+/-0.15 nmol/g, HNE-0.29+/-0.03 nmol/g, Cu, Zn-SOD-117+/-25 U/g, GSH-Px-1723+/-189 U/g, GSSG-R-625+/-112 U/g) especially in mucinous and G3-grade adenocarcinomas as well as clinical IV stage of colorectal cancer. We also observed a decrease of CAT activity (Adc.muc. -40+/-14 U/g, clinical IV stage 33+/-18 U/g vs 84+/-17 U/g, P<0.001) as well as a decreased level of reduced glutathione (clinical IV stage 150+/-48 nmol/g vs 167+/-15 nmol/g, P<0.05) and vitamins C and E (vit. C-clinical IV stage 325+/-92 nmol/g vs 513+/-64 nmol/g, P<0.001; vit. E-clinical IV stage 13.3+/-10.3 nmol/g vs 37.5+/-5.2 nmol/g). Colorectal carcinogenesis is associated with serious oxidative stress and confirms that gradual advancement of oxidative-antioxidative disorders is followed by progression of colorectal cancer.
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For some classes of dietary polyphenols, there are now sufficient intervention studies to indicate the type and magnitude of effects among humans in vivo, on the basis of short-term changes in biomarkers. Isoflavones (genistein and daidzein, found in soy) have significant effects on bone health among postmenopausal women, together with some weak hormonal effects. Monomeric catechins (found at especially high concentrations in tea) have effects on plasma antioxidant biomarkers and energy metabolism. Procyanidins (oligomeric catechins found at high concentrations in red wine, grapes, cocoa, cranberries, apples, and some supplements such as Pycnogenol) have pronounced effects on the vascular system, including but not limited to plasma antioxidant activity. Quercetin (the main representative of the flavonol class, found at high concentrations in onions, apples, red wine, broccoli, tea, and Ginkgo biloba) influences some carcinogenesis markers and has small effects on plasma antioxidant biomarkers in vivo, although some studies failed to find this effect. Compared with the effects of polyphenols in vitro, the effects in vivo, although significant, are more limited. The reasons for this are 1) lack of validated in vivo biomarkers, especially in the area of carcinogenesis; 2) lack of long-term studies; and 3) lack of understanding or consideration of bioavailability in the in vitro studies, which are subsequently used for the design of in vivo experiments. It is time to rethink the design of in vitro and in vivo studies, so that these issues are carefully considered. The length of human intervention studies should be increased, to more closely reflect the long-term dietary consumption of polyphenols.
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In vitro and in vivo laboratory data point to chemoprotective effects of flavonoids on colorectal cancer. However, there has been limited epidemiologic research on the dietary intake of flavonoids and risk of colorectal cancer. Recent expansions of dietary databases to include flavonoid data now make such studies feasible. Association between the six main classes of flavonoids and the risk of colorectal cancer was examined using data from a national prospective case-control study in Scotland, including 1,456 incident cases and 1,456 population-based controls matched on age, sex, and residence area. Dietary, including flavonoid data, were obtained from a validated, self-administered food frequency questionnaire. Risk of colorectal cancer was estimated using conditional logistic regression models in the whole sample and stratified by sex, smoking status, and cancer site and adjusted for established and putative risk factors. After energy adjustment, reductions in colorectal cancer risk associated with the highest quartiles of intake (versus the lowest quartile) were 27% for flavonols [odds ratio (OR), 0.73; P(trend) = 0.012], 32% for quercetin (OR, 0.68; P(trend) = 0.001), 32% for catechin (OR, 0.68; P(trend) < 0.0005); 26% for epicatechin (OR, 0.74; P(trend) = 0.019), and 22% for procyanidins (OR, 0.78; P(trend) = 0.031). The significant dose-dependent reductions in colorectal cancer risk that were associated with increased consumption of flavonols, quercetin, catechin, and epicatechin remained robust after controlling for overall fruit and vegetable consumption or for other flavonoid intake. The risk reductions were greater among nonsmokers, but no interaction beyond a multiplicative effect was present. Sex-specific or cancer-type differences were not observed. No risk reductions were associated with intake of flavones (P(trend) = 0.64), flavonones (P(trend) = 0.22), and phytoestrogens (P(trend) = 0.26). This was the first of several a priori hypotheses to be tested in this large study and showed strong and linear inverse associations of flavonoids with colorectal cancer risk.
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A protein determination method which involves the binding of Coomassie Brilliant Blue G-250 to protein is described. The binding of the dye to protein causes a shift in the absorption maximum of the dye from 465 to 595 nm, and it is the increase in absorption at 595 nm which is monitored. This assay is very reproducible and rapid with the dye binding process virtually complete in approximately 2 min with good color stability for 1 hr. There is little or no interference from cations such as sodium or potassium nor from carbohydrates such as sucrose. A small amount of color is developed in the presence of strongly alkaline buffering agents, but the assay may be run accurately by the use of proper buffer controls. The only components found to give excessive interfering color in the assay are relatively large amounts of detergents such as sodium dodecyl sulfate, Triton X-100, and commercial glassware detergents. Interference by small amounts of detergent may be eliminated by the use of proper controls.
Article
Cet ouvrage de référence, essentiellement descriptif, présente sous une forme principalement graphique, accompagnée de très brefs commentaires, les éléments suivants: 1. les taux d'incidence, standardis és par rapport à la population mondiale, pour 31 localisations ou groupes de localisations cancéreuses de 45 régions appartenant à 19 pays européens qui figurent dans le volume 5 de la série «Cancer Incidence in Five Continents»; 2. les données officielles de mortalité fournies par l'Organisation mondiale de la Santé pour 27 localisations et 26 pays pour la période correspondant à l'incidence, comprise entre 1978 et 1982. Le supplément fournit également les rapports homme/femme d'incidence et de mortalité pour chaque pays et région d'Europe considérés, ainsi que le rang de chaque localisation ou pays/région, respectivement au sein de chaque pays/région ou localisation. Parmi les constatations les plus importantes de ce rapport on relèvera: les taux élevés d'incidence et de mortalité par cancer pulmonaire en Ecosse dans les deux sexes et en Angleterre, les plus bas étant enregistrés en Scandinavie, Espagne et Italie du Sud; les niveaux élevés des néoplasies liées à l'exposition conjointe au tabac et à l'alcool en France, en Suisse romande, en Italie du Nord et en Ecosse, surtout chez la femme; les taux généralement faibles dans les populations méditerranéennes (Espagne, Italie du Sud et Grèce) pour la plupart des autres tumeurs fréquentes, notamment de l'estomac, du colorectum et du sein; les rangs particulièrement élevés des cancers génitaux en Scandinavie, en Suisse et en Italie du Nord, de l'incidence des tumeurs de la vessie dans les régions à haute concentration d'industries chimiques, des tumeurs thyroïdiennes en Scandinavie et en Suisse, et des tumeurs lymphatiques en Ecosse, en Suisse et en Italie du Nord. Pour la majorité des sites les plus importants et, d'une façon générale, les profils d'incidence et de mortalité sont largement superposables, ce qui confirme la bonne qualité et la complémentarité de ces deux types de données. Enfin, on peut constater qu'il existe au sein de l'Europe un intervalle de variation des taux nettement plus large que dans les autres régions développées du monde; l'observation de contrastes géographiques aussi prononcés devrait stimuler la planification de futures études épidémiologiques multicentriques.
Article
Publisher Summary Catalase exerts a dual function: (1) decomposition of H 2 O 2 to give H 2 O and O 2 (catalytic activity) and (2) oxidation of H donors, for example, methanol, ethanol, formic acid, phenols, with the consumption of 1 mol of peroxide (peroxide activity). The kinetics of catalase does not obey the normal pattern. Measurements of enzyme activity at substrate saturation or determination of the K s is therefore impossible. In contrast to reactions proceeding at substrate saturation, the enzymic decomposition of H 2 O 2 is a first-order reaction, the rate of which is always proportional to the peroxide concentration present. Consequently, to avoid a rapid decrease in the initial rate of the reaction, the assay must be carried out with relatively low concentrations of H 2 O 2 (about 0.01 M). This chapter discusses the catalytic activity of catalase. The method of choice for biological material, however, is ultraviolet (UV) spectrophotometry. Titrimetric methods are suitable for comparative studies. For large series of measurements, there are either simple screening tests, which give a quick indication of the approximative catalase activity, or automated methods.
Article
Oxidative stress, resulting from the imbalance between prooxidant and antioxidant states, damages DNA, proteins, cell membranes, and mitochondria and seems to play a role in human breast carcinogenesis. Dietary sources of antioxidants (chemical) and endogenous antioxidants (enzymatic), including the polymorphic manganese superoxide dismutase (MnSOD), can act to reduce the load of oxidative stress. We hypothesized that the valine-to-alanine substitution that seems to alter transport of the enzyme into the mitochondrion, changing its efficacy in fighting oxidative stress, was associated with breast cancer risk and that a diet rich in sources of antioxidants could ameliorate the effects on risk. Data were collected in a case-control study of diet and breast cancer in western New York from 1986 to 1991. Caucasian women with incident, primary, histologically confirmed breast cancer were frequency-matched on age and county of residence to community controls. Blood specimens were collected and processed from a subset of participants in the study (266 cases and 295 controls). Using a RFLP that distinguishes a valine (V) to alanine (A) change in the -9 position in the signal sequence of the protein for MnSOD, we characterized MnSOD genotypes in relation to breast cancer risk. We also evaluated the effect of the polymorphism on risk among low and high consumers of fruits and vegetables. Premenopausal women who were homozygous for the A allele had a 4-fold increase in breast cancer risk in comparison to those with 1 or 2 V alleles (odds ratio, 4.3; 95% confidence interval, 1.7-10.8). Risk was most pronounced among women below the median consumption of fruits and vegetables and of dietary ascorbic acid and alpha-tocopherol, with little increased risk for those with diets rich in these foods. Relationships were weaker among postmenopausal women, although the MnSOD AA genotype was associated with an almost 2-fold increase in risk (odds ratio, 1.8; confidence interval, 0.9-3.6). No appreciable modification of risk by diet was detected for these older women. These data support the hypothesis that MnSOD and oxidative stress play a significant role in breast cancer risk, particularly in premenopausal women. The finding that risk was greatest among women who consumed lower amounts of dietary antioxidants and was minimal among high consumers indicates that a diet rich in sources of antioxidants may minimize the deleterious effects of the MnSOD polymorphism, thereby supporting public health recommendations for the consumption of diets rich in fruits and vegetables as a preventive measure against cancer.
Article
We extracted polyphenols from carob (Ceratonia siliqua L.) pods, and evaluated the in vitro antioxidant activity of the crude polyphenol fraction (CPP). The total polyphenol content in CPP determined by the Folin-Ciocalteu method was 19.2%. The condensed tannin content determined by the vanillin and proanthocyanidin assay systems was 4.37% and 1.36%, respectively. beta-Carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, inhibition of lipid peroxidation by the erythrocyte ghost, and microsomal assay systems were used to evaluate the antioxidant activity. CPP showed a stronger inhibitory effect against the discoloration of beta-carotene than other polyphenol compounds such as catechins and procyanidins. CPP had weaker antioxidant activity in the DPPH free radical scavenging, the erythrocyte ghost, and microsomal systems than authentic polyphenol compounds at the same concentrations. The activity adjusted by the polyphenol concentration was, however, comparable to that of authentic polyphenol compounds. Considering most carob pods are discarded and not effectively utilized at present, these results suggested that carob pods could be utilized as a functional food or food ingredient.
Article
Some water-soluble phenolic acids were investigated as antioxidants, scavengers of hydrogen peroxide (H(2)O(2)) and scavengers of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH(*)). The strongest antioxidant, scavenging of H(2)O(2) and DPPH(*) radical activity was exhibited by 3,4,5-trihydroxybenzoic (gallic) acid and 1,2,3-trihydroxybenzene (pyrogallol) with three hydroxyl groups bonded to the aromatic ring in an ortho position in relation to each other. Phenolic acids with two hydroxyl groups bonded to aromatic ring in the ortho position, such as 3,4-dihydroxycinnamic (caffeic), 3,4-dihydroxybenzoic (protocatechuic) and 2,3-dihydroxybenzoic (o-pyrocatechuic) acids, showed strong antioxidant and anti-radical activity; however, it was lower than that of 3,4,5-trihydroxybenzoic acid or 1,2,3-trihydroxybenzene. 3,5-Dihydroxybenzoic (alpha-resorcylic) and 2,4-dihydroxybenzoic (beta-resorcylic) acids with two hydroxyls bonded in the meta position in relation to each other showed moderate antioxidant and low DPPH(*) and hydrogen peroxide scavenging activity. Compounds with one hydroxyl group such as 3-hydroxybenzoic, 4-hydroxyphenylacetic and 2-hydroxybenzoic (salicylic) acids, exhibited the lowest anti-radical and antioxidant activity. The results obtained show that the antioxidant and anti-radical activity of phenolic acids correlated positively with the number of hydroxyl groups bonded to the aromatic ring. The model of an ortho substitution of hydroxyl groups to the aromatic ring seems to be adequate for antioxidant and H(2)O(2) or DPPH(*) scavenging activity of phenolic acids.
Article
Functional foods need to be assessed for beneficial effects to support claims, but also for toxic effects. This report describes two examples of how complex food samples are initially characterized in human cells in vitro. Water extracts of green tea (GT) and black carrots (BC) were analyzed for key ingredients (catechins and anthocyanidins, respectively). Extracts, reconstituted mixtures of the major ingredients or individual compounds [(-)-epigallocatechin gallate or cyanidin, respectively] were evaluated in parallel using human colon cells (HT29 clone 19A). End points of cytotoxicity included determination of membrane integrity, proliferation inhibition, and genetic damage. Cells were pretreated with plant compounds at sub-toxic concentrations, and their resistance to toxicity of H2O2 was evaluated as a parameter of protection. The extracts reduced cell viability (BC) and cell growth (BC, GT) and caused DNA damage (BC, GT). They were more toxic than their key ingredients. Neither GT-samples nor BC protected against H2O2-induced DNA damage, whereas cyanidin did. In vitro analysis of extracts from functional foods firstly aims at defining the sub-toxic concentrations at which protective activities are then further characterized. It also allows comparing responses of complex samples and individual compounds, which is important since effects from protective food ingredients can be masked by accompanying toxic components.
Article
Oxidative stress, produced as a consequence of normal metabolism or induced by extraneous stimuli, has been proved to be a mediator of cell death. The inherent antioxidant defense system and exogenous antioxidants can help the body to combat this oxidative stress-induced cell death. In this study, we explored the antiapoptotic potential of gallic acid, a dietary phenolic having antioxidative and anticarcinogenic properties, in normal human peripheral blood lymphocytes (PBLs). Incubation of PBLs with 100 microM H2O2 for 1.5-2.0 h induced phosphatidyl serine externalisation, lipid peroxidation and high molecular weight DNA fragmentation. Pretreatment of lymphocytes with gallic acid for 18 h could effectively inhibit lipid peroxidation and apoptosis induced by oxidative stress. Treatment of PBLs with gallic acid failed to induce any change in the expression of Bcl-2, an antiapoptotic protein. It seems that the protection provided by gallic acid was due to its direct action in the scavenging of free radicals as it was found to be a stronger antiradical than trolox, a water- soluble analogue of vitamin E.
Article
The polyphenolic patterns of carob pods (Ceratonia siliqua L.) and derived products were identified and quantified using high-performance liquid chromatography-UV absorption-electrospray ion trap mass spectrometry after pressurized liquid extraction and solid-phase extraction. In carob fiber, 41 individual phenolic compounds could be identified. In addition, spectrophotometric quantification using the Folin-Ciocalteu and vanillin assays was performed, and the antioxidative activity was determined as the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Carob pods contain 448 mg/kg extractable polyphenols comprising gallic acid, hydrolyzable and condensed tannins, flavonol-glycosides, and traces of isoflavonoids. Among the products investigated, carob fiber, a carob pod preparation rich in insoluble dietary fiber (total polyphenol content = 4142 mg/kg), shows the highest concentrations in flavonol-glycosides and hydrolyzable tannins, whereas roasted carob products contain the highest levels of gallic acid. The production process seems to have an important influence on the polyphenolic patterns and quantities in carob products.
Article
The effect of tannic acid (TA), gallic acid (GA), propyl gallate (PA) and ellagic acid (EA) on DNA damage in human lymphocytes induced by food mutagens [3-amino-1-methyl-5H-pyrido (4,3-b) indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimadazo (4,5-b) pyridine (PhIP) or H2O2 was evaluated by using single-cell electrophoresis (comet assay). The toxicity of these tested compounds (0.1-100 microg/ml) on lymphocytes was not found. These compounds did not cause DNA strand breaks at lower concentrations of 0.1-10 microg/ml. At a concentration of 100 microg/ml, TA and GA exhibited slight DNA damage, whereas PA and EA showed no DNA strand breaks. TA and its related compounds decreased the DNA strand breaks induced by Trp-P-2, PhIP or H2O2 at concentrations of 0.1-10 microg/ml. DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycoslase (FPG)] were used to examine the levels of oxidised pyrimidines and purines in human lymphocytes induced by H2O2. All the compounds at 10 microg/ml can reduce the level of FPG sensitive sites. However, only EA inhibited the formation of EndoIII sensitive sites. The results indicated that these compounds can enhance lymphocytes resistance towards DNA strand breaks induced by food mutagens or H2O2 in vitro.
Article
Foods and beverages rich in phenolic compounds, especially flavonoids, have often been associated with decreased risk of developing several diseases. However, it remains unclear whether this protective effect is attributable to the phenols or to other agents in the diet. Alleged health-promoting effects of flavonoids are usually attributed to their powerful antioxidant activities, but evidence for in vivo antioxidant effects of flavonoids is confusing and equivocal. This may be because maximal plasma concentrations, even after extensive flavonoid intake, may be low (insufficient to exert significant systemic antioxidant effects) and because flavonoid metabolites tend to have decreased antioxidant activity. Reports of substantial increases in plasma total antioxidant activity after flavonoid intake must be interpreted with caution; findings may be attributable to changes in urate concentrations. However, phenols might exert direct effects within the gastrointestinal tract, because of the high concentrations present. These effects could include binding of prooxidant iron, scavenging of reactive nitrogen, chlorine, and oxygen species, and perhaps inhibition of cyclooxygenases and lipoxygenases. Our measurements of flavonoids and other phenols in human fecal water are consistent with this concept. We argue that tocopherols and tocotrienols may also exert direct beneficial effects in the gastrointestinal tract and that their return to the gastrointestinal tract by the liver through the bile may be physiologically advantageous.
Article
Polyphenols are abundant micronutrients in our diet, and evidence for their role in the prevention of degenerative diseases is emerging. Bioavailability differs greatly from one polyphenol to another, so that the most abundant polyphenols in our diet are not necessarily those leading to the highest concentrations of active metabolites in target tissues. Mean values for the maximal plasma concentration, the time to reach the maximal plasma concentration, the area under the plasma concentration-time curve, the elimination half-life, and the relative urinary excretion were calculated for 18 major polyphenols. We used data from 97 studies that investigated the kinetics and extent of polyphenol absorption among adults, after ingestion of a single dose of polyphenol provided as pure compound, plant extract, or whole food/beverage. The metabolites present in blood, resulting from digestive and hepatic activity, usually differ from the native compounds. The nature of the known metabolites is described when data are available. The plasma concentrations of total metabolites ranged from 0 to 4 mumol/L with an intake of 50 mg aglycone equivalents, and the relative urinary excretion ranged from 0.3% to 43% of the ingested dose, depending on the polyphenol. Gallic acid and isoflavones are the most well-absorbed polyphenols, followed by catechins, flavanones, and quercetin glucosides, but with different kinetics. The least well-absorbed polyphenols are the proanthocyanidins, the galloylated tea catechins, and the anthocyanins. Data are still too limited for assessment of hydroxycinnamic acids and other polyphenols. These data may be useful for the design and interpretation of intervention studies investigating the health effects of polyphenols.
Article
Phenolic compounds are not completely absorbed in the small intestine and so enter the colon, where they might exert physiological effects. To identify phenolics that are present in normal human colon, fecal water was prepared from 5 free-living volunteers with no dietary restrictions and analyzed by gas chromatography-mass spectrometry. Daily measurements were also performed on a single individual to examine the variation more closely. Levels of polyphenols were variable between individuals. Naringenin and quercetin had mean concentrations of 1.20 and 0.63 microM. All other flavonoids examined were present < or =0.17 microM. Simple phenolic and other aromatic acids were present at much higher concentrations. The major components were phenylacetic acid, 479 microM; 3-phenylpropionic acid, 166 microM; 3-(4-hydroxy)-phenylpropionic acid, 68 microM; 3,4-dihydroxycinnamic acid, 52 microM; benzoic acid, 51 microM; 3-hydroxyphenylacetic acid, 46 microM; and 4-hydroxyphenylacetic acid, 19 microM. Other phenolic acids ranged from 0.04 to 7 microM. Decreased dietary phenolic intake caused a decrease in polyphenol and monophenolic acid concentration in fecal water 24 h later. This study is the first to measure the range of aromatic compounds in human fecal water and demonstrates that phenolic acid concentrations are high. The biological effects of phenolics may play an important role in colon function.
Article
There has been controversy as to whether the antiproliferative activity of dietary phenolic substances on cancer cells is due to the bioactivities of phenolics or the generation of hydrogen peroxide (H2O2) in media as an artifact. This study was to investigate whether the formation of H2O2 by different phenolics induces acute toxicity and carcinogenicity in normal rat liver epithelial cells. Gallic acid, one of the major antioxidants present in fruits and vegetables, dose-dependently generated considerably more H2O2 in DMEM media without cells than did quercetin. Gallic acid exerted stronger antiproliferative activity than quercetin on both Caco-2 human colon cancer cells (Caco-2 cells) and WB-F344 normal rat liver epithelial cells (WB cells) cultured in DMEM media, and the effect was partially reduced by catalase. Furthermore, gallic acid (but not quercetin) also inhibited gap-junction intercellular communication (GJIC; a carcinogenic phenomenon), which was in part protected by the addition of catalase. Exogenous H2O2 addition also inhibited the proliferation of both Caco-2 cells and WB cells and inhibited GJIC in a dose-dependent manner, but these effects were almost abolished by the treatment with catalase. From these results it is concluded that the antiproliferative effects of some antioxidants on cancer cells are partially due to their prooxidant actions.
Article
There is evidence that consumption of certain dietary ingredients may favourably modulate biotransformation of carcinogens. Associated with this is the hypothesis that the risk for developing colorectal cancer could be reduced, since its incidence is related to diet. Two main groups of biotransformation enzymes metabolize carcinogens, namely Phase I enzymes, which convert hydrophobic compounds to more water-soluble moieties, and Phase II enzymes (e.g. glutathione S-transferases [GST]), which primarily catalyze conjugation reactions. The conjugation of electrophilic Phase I intermediates with glutathione, for instance, frequently results in detoxification. Several possible colon carcinogens may serve as substrates for GST isoenzymes that can have marked substrate specificity. The conjugated products could be less toxic/genotoxic if GSTs are induced, thereby reducing exposure. Thus, numerous studies have shown that the induction of GSTs by antioxidants enables experimental animals to tolerate exposure to carcinogens. One important mechanism of GST induction involves an antioxidant-responsive response element (ARE) and the transcription factor nuclear factor E2-related factor 2 (Nrf2), which is bound to the Kelch-like ECH associated protein 1 (Keap1) in the cytoplasm. Antioxidants may disrupt the Keap-Nrf2 complex, allowing Nrf2 to translocate to the nucleus and mediate expression of Phase II genes via interaction with the ARE. GSTs are also induced by butyrate, a product of gut flora-derived fermentation of plant foods, which may act via different mechanisms, e.g. by increasing histone acetylation. GSTs are expressed with high inter-individual variability in human colonocytes, which points to large differences in cellular susceptibility to xenobiotics. Enhancing expression of GSTs in human colon tissue could therefore contribute to reducing cancer risks. However, it has not been demonstrated in humans that this mechanism is associated with cancer prevention. In the future, it will be useful to determine GSTs during dietary intervention studies to enhance our understanding of this protective mechanism.
Article
The irradiation of fat results in the formation of 2-alkylcyclobutanones, a new class of food contaminants. Results of previous in vitro studies with primary human colon cells and in vivo experiments with rats fed with 2-alkylcyclobutanones indicated that these radiolytic derivatives may be genotoxic and enhance the progression of colon tumors. The underlying mechanisms of these effects, however, are not clearly understood. Therefore we performed additional investigations to elucidate the genotoxic potential of 2-dodecylcyclobutanone (2dDCB) that is generated from palmitic acid. In particular, we explored the relative sensitivities of human colon cells, representing different stages of tumor development and healthy colon tissues, respectively. HT29clone19A cells, LT97 adenoma cells and primary human epithelial cells were exposed to 2dDCB (150-2097 microM). We determined cytotoxic effects using trypan blue exclusion. Genotoxicity, reflected as strand breaks, was assessed using the alkaline version of the comet assay and chromosomal abnormalities were investigated by 24-color fluorescence-in-situ-hybridization. 2dDCB was cytotoxic in a time- and dose-dependent manner in LT97 adenoma cells and in freshly isolated primary cells but not in the human colon tumor cell line. Associated with this was a marked induction of DNA damage by 2dDCB in LT97 adenoma cells and in freshly isolated colonocytes, whereas in the HT29clone19A cells no strand breaks were detectable. A long-term incubation of LT97 adenoma cells with lower concentrations of 2dDCB revealed cytogenetic effects. In summary, 2dDCB was clearly genotoxic in healthy human colon epithelial cells and in cells representing preneoplastic colon adenoma. These findings provide additional evidence that this compound may be regarded as a possible risk factor for processes in colon carcinogenesis related to initiation and progression.
Article
Observed weak or null associations between fruit and vegetable intake and breast cancer risk could be due to heterogeneity in endogenous antioxidant capabilities. The authors evaluated potential relations between a functional polymorphism in catalase, an antioxidant enzyme, and breast cancer risk, particularly in relation to fruit and vegetable intake and supplement use. Women (1,008 cases and 1,056 controls) in the Long Island Breast Cancer Study Project (1996–1997) were interviewed, completed a food frequency questionnaire, and provided blood for genotyping. The high-activity catalase CC genotype was associated with an overall 17% reduction in risk of breast cancer compared with having at least one variant T allele (odds ratio = 0.83, 95% confidence interval: 0.69, 1.00). Vegetable and, particularly, fruit consumption contributed to the decreased risk associated with the catalase CC genotype. Associations were more pronounced among women who did not use vitamin supplements, with a significant multiplicative interaction (pinteraction = 0.02) for the CC genotype and high fruit intake (odds ratio = 0.59, 95% confidence interval: 0.38, 0.89), and there was no association among supplement users. These results indicate the importance of diet, rather than supplement use, in concert with endogenous antioxidant capabilities, in the reduction of breast cancer risk. CC genotypes were prevalent in approximately 64% of controls; thus, the preventive potential for fruit consumption has widespread implications.
Article
H(2)O(2) is a reactive oxygen species that has drawn much interest because of its role as a second messenger in receptor-mediated signaling. Mammalian 2-Cys peroxiredoxins have been shown to eliminate efficiently the H(2)O(2) generated in response to receptor stimulation. 2-Cys peroxiredoxins are members of a novel peroxidase family that catalyze the H(2)O(2) reduction reaction in the presence of thioredoxin, thioredoxin reductase and NADPH. Several lines of evidence suggest that 2-Cys peroxiredoxins have dual roles as regulators of the H(2)O(2) signal and as defenders of oxidative stress. In particular, 2-Cys peroxiredoxin appears to provide selective, specific and localized control of receptor-mediated signal transduction. Thus, the therapeutic potential of 2-Cys peroxiredoxins is clear for diseases, such as cancer and cardiovascular diseases, that involve reactive oxygen species.
Article
Flavonoids from fruits and vegetables probably reduce risks of diseases associated with oxidative stress, including cancer. Apples contain significant amounts of flavonoids with antioxidative potential. The objectives of this study were to investigate such compounds for properties associated with reduction of cancer risks. We report herein that apple flavonoids from an apple extract (AE) inhibit colon cancer cell growth and significantly modulate expression of genes related to xenobiotic metabolism. HT29 cells were treated with AE at concentrations delivering 5-50 microM of one of the major ingredients, phloridzin ("phloridzin-equivalents," Ph.E), to the cell culture medium, with a synthetic flavonoid mixture mimicking the composition of the AE or with 5-100 microM individual flavonoids. HT29 cell growth was inhibited by the complex extract and by the mixture. HT29 cells were treated with nontoxic doses of the AE (30 microM, Ph.E) and after 24 h total RNA was isolated to elucidate patterns of gene expression using a human cDNA-microarray (SuperArray) spotted with 96 genes of drug metabolism. Treatment with AE resulted in an upregulation of several genes (GSTP1, GSSTT2, MGST2, CYCP4F3, CHST5, CHST6, and CHST7) and downregulation of EPHX1, in comparison to the medium controls. The enhanced transcriptional activity of GSTP1 and GSTT2 genes was confirmed with real-time qRT-PCR. On the basis of the pattern of differential gene expression found here, we conclude that apple flavonoids modulate toxicological defense against colon cancer risk factors. In addition to the inhibition of tumor cell proliferation, this could be a mechanism of cancer risk reduction.
Article
Recent studies have shown that bread supplemented with functional ingredients was more chemoprotective than nonsupplemented bread. Here we investigated components of a German wheat bread supplemented with green coffee antioxidants (GC) to assess basic biological activities in human cells in culture. We analyzed chlorogenic acid (ChA) in the bread and determined antioxidative activities. Human colon (HT29) and liver (HepG2) cells were incubated with GC and with aqueous extracts of freeze-dried breads, after which cell survival (4' ,6-diamino-2- phenylindole dihydrochloride assay) and H(2)O(2)-induced DNA damage (comet assay) were determined. GC and supplemented bread contained 7- and 880-fold more ChA than normal bread and were significantly more antioxidative (ferric reducing ability of plasma assay, 2.9- and 265-fold; Trolox equivalent antioxidant capacity assay, 1.3- and 24-fold, respectively). Treatment of cells for 24 to 72 h with the samples resulted in a significant inhibition of cell survival in a dose-dependent manner. HepG2 liver cells were more susceptible than HT29 colon cells. No genotoxicity or cytotoxicity was observed after treatment of cells with GC, ChA, or the bread samples. H(2)O(2)-induced DNA damage was reduced significantly after treatment with GC, ChA, and supplemented bread. In conclusion, the supplementation of bread with GC improves the chemoprotective property of normal bread under these in vitro cell culture conditions. Supplementation also increases ChA content and antioxidative capacity. The treatment of the cells with supplemented bread increases resistance of colon and liver cells against H(2)O(2), a source of oxidative stress.
Article
An extract of the Mediterranean carob (Ceratonia siliqua L.) pod (carob fibre extract), products formed after its fermentation by the gut flora and the major phenolic ingredient gallic acid (GA), were comparatively investigated for their influence on survival and growth parameters of colon adenocarcinoma HT29 cells and adenoma LT97 cells. Hydrogen peroxide (H2O2) formation in the cell culture media was quantified. After 1h 97+/-4 microM or 70+/-15 microM were found in HT29 medium and 6+/-1 microM or 3+/-3 microM in LT97 medium for carob fibre extract or GA, respectively. After 72 h carob fibre extract reduced survival of rapidly proliferating HT29 cells (by 76.4+/-12.9%) whereas metabolic activity and DNA-synthesis were only transiently impaired. Survival of slower growing LT97 cells was less decreased (by 21.5+/-12.9%), but there were marked effects on DNA-synthesis (reduction by 95.6+/-7%, 72 h). GA and fermented carob fibre did not have comparable effects. Thus, carob fibre extract resulted in H2O2 formation, which, however, could not explain impairment of cell growth. The differently modulated growth of human colon cell lines was more related to proliferation rates and impairment of DNA-synthesis than to H2O2 formation.
Revised manuscript received
  • Klenow
Received for review September 15, 2008. Revised manuscript received December 22, 2008. Accepted February 2, 2009. JF802872B 3004 J. Agric. Food Chem., Vol. 57, No. 7, 2009 Klenow et al.
on human cancer cell lines
  • Boerl
Boerl, on human cancer cell lines. Int. J. Oncol. 2007, 30 (3), 605–613.