Anticlastogenic activity of cacao: inhibitory effect of cacao liquor polyphenols against mitomycin C-induced DNA damage

Theobromacacao Criollo var. Beans: Biological Properties and Chemical Profile

Theobroma cacao provides precious products such as polyphenol-rich beans that are useful for nutraceutical purposes. The geographical area may influence the chemical composition of raw cocoa beans in terms of the polyphenols and biological qualities of the products. This work aimed to investigate the biological properties and the chemical composition of two different samples of Criollo var. cocoa raw beans coming from two areas (Indonesia; Peru). Beans underwent biphasic extraction obtaining lipophilic and hydroalcoholic extracts. The extracts were tested for antiradical, antimutagenic, and antigenotoxic effects. Cell viability inhibition toward breast, gastric/esophageal colorectal adenocarcinoma, and hepatoblastoma human cell lines was evaluated. Extracts were chemically investigated through UV-Vis spectroscopy and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QqTOF MS/MS). Results showed that the Indonesian bean hydroalcoholic extracts were able to scavenge 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cation radical better than the Peruvian hydroalcoholic extracts (ECs₅₀: 72.63 vs. 322.20 μg/mL). Extracts showed antimutagenic and antigenotoxic activity. The viability inhibitory effect on breast and hepatic cancer cells was reached only for the Indonesian hydroalcoholic extracts at hundreds of μg/mL. Phenylpropenoyl-L-amino acids, hydroxycinnamoyl aminoacids conjugates, and procyanidin compounds were found mainly in the hydroalcoholic extracts, whereas fatty acids and lyso-phospholipids were found mainly in lipophilic fractions. Fatty acid and (epi)catechins appeared to be affected by different environmental conditions of the geographical areas.

Decrease of the DXR-induced genotoxicity and nongenotoxic effects of Theobroma cacao revealed by micronucleus assay

This study evaluated the genotoxicity of lyophilized glycolic extract of Theobroma cacao Linné seeds (TCL), using the micronucleus assay in bone marrow of mice. The interaction between TCL and doxorubicin (DXR) was also analyzed. Experimental groups were evaluated 24-48 h after treatment with N-Nitroso-N-ethylurea (NEU: 50 mg/kg), DXR (5 mg/kg), NaCl (145 mM), TCL (0.5-2 g/kg), and TCL (2 g/kg) in combination with DXR (antigenotoxic assays). Analysis of micronucleated polychromatic erythrocytes (MNPCEs) showed no significant differences between all the treatment doses of TCL and NaCl control. Mice experimentally treated with DXR and NEU significantly induced MNPCEs. However, a significant reduction of MNPCEs was also observed when TCL was administered in combination with the chemotherapeutic agent DXR. The analysis of the PCE/NCE ratio revealed no significant differences between the NaCl control, all doses of TCL, and DXR. However, there were significant differences in the PCE/NCE ratio between positive NEU control and all other treatments. The PCE/NCE ratio observed after treatment with TCL and DXR showed significant differences and intermediate values to controls (NaCl and NEU). This study suggests absence of genotoxicity and cytotoxicity of TCL, regardless of dose, sex, and time. TCL reduced genotoxic effects induced by DXR, suggesting potential antigenotoxic effects.

Interactions between bioactive components determine antioxidant, cytotoxic and nutrigenomic activity of cocoa powder extract

Numerous studies have shown, rather disappointingly, that isolated bioactive phytochemicals are not as biologically effective as natural plant products. Such a discrepancy may be explained by the concept of food synergy, which was verified in this research for cocoa extract versus its major components with regard to cancer chemoprevention. The evaluation embraced the relationship between redox properties evaluated in cell-free systems with the aid of free radicals scavenging method and differential pulse voltammetry, and redox associated anticarcinogenic activities (cellular antioxidant activity, cytotoxicity, nutrigenomic activity) in human colon adenocarcinoma cell line exposed to either cocoa powder extract or artificial mixtures of cocoa bioactives at matching concentrations. In contrast to expectations, our results showed that the stepwise enrichment with antioxidants caused no gradual increase in the antioxidant activity of the model mixtures; also, these model mixtures did not reach the reducing potential of cocoa in the cell-free systems or cellular model employed. Further, the biological activities examined in colon adenocarcinoma cells did not alter in a stepwise manner that could reflect the gradual changes in composition of bioactive ingredients. In conclusion, the experiments presented here showed that the growing complexity of a mixture of phytochemicals seems to create a new redox bioactive substance rather than enrich the mixture with new activities, characteristic of the compound added. It follows that no simple, predictable relationship can be expected between the chemopreventive potential and the composition of real food items containing a complicated set of non-toxic redox active ingredients. Our observations suggest that the interactions between different bioactive compounds and food matrix components are cooperating factors determining the final bioactivity of foods.

Evidence of Some Natural Products with Antigenotoxic Effects. Part 2: Plants, Vegetables, and Natural Resin

Cancer is one of the leading causes of death worldwide. The agents capable of causing damage to genetic material are known as genotoxins and, according to their mode of action, are classified into mutagens, carcinogens, or teratogens. Genotoxins are also involved in the pathogenesis of several chronic degenerative diseases, including hepatic, neurodegenerative, and cardiovascular disorders; diabetes; arthritis; cancer; chronic inflammation; and ageing. In recent decades, researchers have found novel bioactive phytocompounds able to counteract the effects of physical and chemical mutagens. Several studies have shown the antigenotoxic potential of different fruits and plants (Part 1). In this review (Part 2), we present a research overview conducted on some plants and vegetables (spirulina, broccoli, chamomile, cocoa, ginger, laurel, marigold, roselle, and rosemary), which are frequently consumed by humans. In addition, an analysis of some phytochemicals extracted from those vegetables and the analysis of a resin (propolis),whose antigenotoxic power has been demonstrated in various tests, including the Ames assay, sister chromatid exchange, chromosomal aberrations, micronucleus, and comet assay, was also performed.

Review: Health Effects of Cocoa Flavonoids

Flavonoids are phenolic substances widely found in fruits and vegetables. Many epidemiological studies associate the ingestion of flavonoids with a reduced risk of cardiovascular disease and certain types of cancer. These effects are due to the physiological activity of flavonoids in the reduction of oxidative stress, inhibiting low-density lipoproteins (LDL) oxidation and platelet aggregation, acting as vasodilators in blood vessels, inhibiting the adherence of monocytes to the vascular endothelium, promoting fibrinolysis, acting as immunomodulators and anti-inflammatory agents and as inhibitors in the different phases of tumour process. Cocoa is an important source of polyphenols, which comprise 12-18% of its total weight on dry basis; the major phenolic compounds are epicatechin, proanthocyanidins and cate-chin. The levels of flavonoids contained are higher than the ones founds in apples, onions or wine, foods known for their high amount of phenolic compounds. Cocoa and cocoa products are important sources of flavonoids in our diet. In the Dutch population chocolate contributes up to 20% of the total flavonoid intake in adults, and in children the percentage is even higher. The bioavailability of these compounds depends on other food constituents, and their interaction with the food matrix. This article reviews current evidence on the health effects of cocoa flavonoids in our diet. The compiled data supports the premise that the consumption of cocoa flavonoids is beneficial to human health.

Cocoa polyphenols and their potential benefits for human health

This paper compiles the beneficial effects of cocoa polyphenols on human health, especially with regard to cardiovascular and inflammatory diseases, metabolic disorders, and cancer prevention. Their antioxidant properties may be responsible for many of their pharmacological effects, including the inhibition of lipid peroxidation and the protection of LDL-cholesterol against oxidation, and increase resistance to oxidative stress. The phenolics from cocoa also modify the glycemic response and the lipid profile, decreasing platelet function and inflammation along with diastolic and systolic arterial pressures, which, taken together, may reduce the risk of cardiovascular mortality. Cocoa polyphenols can also modulate intestinal inflammation through the reduction of neutrophil infiltration and expression of different transcription factors, which leads to decreases in the production of proinflammatory enzymes and cytokines. The phenolics from cocoa may thus protect against diseases in which oxidative stress is implicated as a causal or contributing factor, such as cancer. They also have antiproliferative, antimutagenic, and chemoprotective effects, in addition to their anticariogenic effects.

Flavor formation and character in cocoa and chocolate: a critical review

Chocolate characters not only originate in flavor precursors present in cocoa beans, but are generated during post-harvest treatments and transformed into desirable odor notes in the manufacturing processes. Complex biochemical modifications of bean constituents are further altered by thermal reactions in roasting and conching and in alkalization. However, the extent to which the inherent bean constituents from the cocoa genotype, environmental factors, post-harvest treatment, and processing technologies influence chocolate flavor formation and relationships with final flavor quality, has not been clear. With increasing speciality niche products in chocolate confectionery, greater understanding of factors contributing to the variations in flavor character would have significant commercial implications.

Anticlastogenic activity of thymoquinone against benzo(a)pyrene in mice

Thymoquione (TQ), the main constituent of the volatile oil of Nigella sativa seeds, has been shown to protect mice against benzo(a)pyrene [B(a)P]-induced forestomach carcinogenesis. The present investigation was undertaken to study the possible chemopreventive activity of TQ, supplemented in the drinking water, against B(a)P-induced chromosomal aberrations (CAs) in mouse bone marrow cells. Male Swiss albino mice received TQ (0.01% in drinking water) daily for 28 days. The daily dose of TQ was estimated to be 10mg/kg based on the calculated average daily water consumption by mice. From day 9, the carcinogen, B(a)P, was given by gastric intubation at dose level of 50mg/kg on alternative days for a total of 8 doses. On day 29, all mice were transferred to a normal drinking tap water. Control groups received corn oil vehicle, TQ alone or B(a)P alone. All mice were sacrificed at 12 weeks after the end of the treatment. Chromosome preparations were made of bone marrow. Cytogenetic end points screened were the frequencies of CAs and damaged cells induced. Daily intake of TQ after and before or during exposure to B(a)P significantly reduced the frequencies of CAs and damaged cells compared to the highly clastogenic activity of B(a)P alone.

Effect of cacao liquor extract on tumor marker enzymes during chemical hepatocarcinogenesis in rats

This study investigated the effect of cacao liquor extract (CLE) on tumor marker enzymes--alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), glutathione-S-transferase (GST), and glutathione reductase (GR) activities--in plasma and/or liver of hepatocarcinogenic rats, which were induced with diethylnitrosamine and 2-acetylaminofluorene. Twenty-nine male Sprague-Dawley rats (weighing 150-330 g) were divided into four groups (n = 6-8): normal control group (N), normal group + CLE (NE), cancer group (C), and cancer group + CLE (CE). Analysis of variance showed significant differences (P<.05) in the specific activities of ALP, GGT, and GST between the C and N groups. However, GR activity for the C group was not significantly different compared with the N group. In the CE group, the specific activities of ALP, GGT, GST, and GR were significantly lower (P<.05) compared with the C group. The findings showed that CLE could lower the activity of tumor marker enzymes of rats during hepatocarcinogenesis. Based on the results obtained, polyphenol compounds present in the cacao liquor, extracted by using ethanol, have the potential in decreasing the severity of hepatocarcinogenesis.

The Microbiology of Cocoa Fermentation and its Role in Chocolate Quality

The first stage of chocolate production consists of a natural, seven-day microbial fermentation of the pectinaceous pulp surrounding beans of the tree Theobroma cacao. There is a microbial succession of a wide range of yeasts, lactic-acid, and acetic-acid bacteria during which high temperatures of up to 50 degrees C and microbial products, such as ethanol, lactic acid, and acetic acid, kill the beans and cause production of flavor precursors. Over-fermentation leads to a rise in bacilli and filamentous fungi that can cause off-flavors. The physiological roles of the predominant micro-organisms are now reasonably well understood and the crucial importance of a well-ordered microbial succession in cocoa aroma has been established. It has been possible to use a synthetic microbial cocktail inoculum of just 5 species, including members of the 3 principal groups, to mimic the natural fermentation process and yield good quality chocolate. Reduction of the amount of pectin by physical or mechanical means can also lead to an improved fermentation in reduced time and the juice can be used as a high-value byproduct. To improve the quality of the processed beans, more research is needed on pectinase production by yeasts, better depulping, fermenter design, and the use of starter cultures.

Chemoprevention of lung carcinogenesis by cacao liquor proanthocyanidins in a male rat multi-organ carcinogenesis model

The effects of cacao liquor proanthocyanidins (CLPr) on tumorigenesis were investigated using a multi-organ carcinogenesis model in male F344 rats receiving combined treatment with a single i.p. injection of diethylnitrosamine (100 mg/kg body wt), four i.p. injections of N-methylnitrosourea (20 mg/kg body wt), four s.c. injections of dimethylhydrazine (40 mg/kg body wt), along with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine and then 0.1% 2,2'-dihydroxy-di-n-propylnitrosamine, both in the drinking water, for 2 weeks each, during the initial 4-week period (DMBDD treatment). Starting 1 week thereafter, rats were administered CLPr at a dose of 0.025% or 0.25% and the experiment was terminated at week 36. The final survival rate for the DMBDD+0.25% CLPr group was significantly greater than for the DMBDD alone group. In the lung, significant reduction in the incidence and multiplicity of carcinomas was also observed, and in the thyroid, quantitative values for adenomas also tended to decrease in a CLPr dose-dependent manner. No significant modification in the small intestine, colon or kidney was evident. These results indicate that CLPr exerts chemopreventive effects in the lung without any promoting influence in other major organs.

Effects of cacao liquor proanthocyanidins on PhIP-induced mutagenesis in vitro, and in vivo mammary and pancreatic tumorigenesis in female Sprague-Dawley rats

The effects of cacao liquor proanthocyanidins (CLPr) on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mutagenesis in vitro and on in vivo carcinogenesis in female Sprague-Dawley (SD) rats were investigated. In the Ames assay using Salmonella typhimurium TA98, CLPr showed strong antimutagenic effects against PhIP when assayed in the presence of S-9 mixture. For determination of the influence on initiation and subsequent development of lesions, CLPr (0.025% or 0.25%) were fed during the period of PhIP application (100 mg/kg given to rats via gastric tubes eight times over 4 weeks), or thereafter until the termination at 48 weeks. CLPr treatments did not affect body or organ weights. The incidences, multiplicities and volumes of mammary tumors in the 0.25% CLPr (post-initiation) group showed a tendency to decrease as compared to PhIP alone group values, although without statistical significance. The incidences of preneoplastic eosinophilic foci in the exocrine pancreas were significantly (P<0.05) decreased in a dose-dependent manner when CLPr were given during the initiation period. These results indicate that CLPr inhibit in vitro mutagenicity of PhIP, as well as rat pancreatic carcinogenesis in the initiation stage, but not mammary carcinogenesis induced by PhIP.