Absence of carcinogenic and anticarcinogenic effects of annatto in the rat liver medium-term assay

Dyes Used in Processed Meat Products in the Polish Market, and Their Possible Risks and Benefits for Consumer Health

Manufacturers are obliged to label processed meat products with information concerning the additives used and nutritional values. The aim of the study was to identify the dyes most frequently used in processed meat, evaluate their influence on specific food qualities, assess whether their use was correct and review their effect on health. The analysis was based on information on the labels and images of processed meat, and used a generalised linear model with a binary dependent variable. The risks and benefits for human health were defined based on the available literature. Twelve dyes were found to be used in the manufacture of processed meat. Carmine was found in 183 of 273 (67.03%) evaluated assortments containing dyes. The occurrence of water, flavourings and high fat and carbohydrate contents increased the chances that a dye would be present in a particular product. Unauthorised use of food additives was found in 20 products, with smoked meat products demonstrating the highest number of non-compliances. In general, the dyes used with food are considered safe; however, reservations are associated with the use of E150C and E150D caramels due to their potential carcinogenic effect, and carmine and annatto due to their allergic effects.

A toxicological evaluation of geranylgeraniol

Geranylgeraniol (GGOH) is an isoprenoid compound found in annatto seeds and an intermediate of the mevalonate pathway found within organisms serving various functions. Toxicological studies on its safety profile are not readily available. To assess the safety of GGOH, a molecularly distilled, food grade annatto oil, consisting of approximately 80% trans-GGOH, was subjected to a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and an in vivo mammalian micronucleus test in order to investigate its genotoxic potential and a 90-day repeated-dose oral toxicity study in rats in order to investigate its potential subchronic toxicity and identify any target organs. No evidence of mutagenicity or genotoxic activity was observed under the applied test systems. In the 90-day study, male and female Hsd. Han Wistar rats were administered daily doses of 0, 725, 1450, and 2900 mg/kg bw/day by gavage. Treatment-related adverse effects were observed in the forestomach at all dose levels and in the liver at the intermediate- and high-dose levels. Based on these results, the lowest observed adverse effect level (LOAEL) for local effects and the no observed adverse effect level (NOAEL) for systemic effects were determined as 725 mg/kg bw/day.

Adsorption of natural annatto dye by kaolin: kinetic and equilibrium

The adsorption of annatto dye was analysed using kaolin clay as the adsorbent. In this work, the influence of the adsorbent particle size, agitation (0 and 100 rpm), temperature (25, 40, and 60°C), and salt presence (sodium chloride and sodium sulphate at 1, 2 and 3 wt%) on the adsorption process was studied. The adsorption increased 14.21% for particles smaller than 45 µm and the agitation (100 rpm) led to an increase of 22.41% compared to the system without agitation. The ΔG° (237.711 kJmol^-1) indicated that the adsorption process was spontaneous. The negative value of ΔS° (-408.999 Jmol^-1K^-1) and ΔH° (-115.829 kJmol^-1) showed an exothermic physisorption process. The adsorption kinetics follows the pseudo-second-order model. In the adsorption equilibrium, the tested models provided good correlation coefficients ranging from 0.744 to 0.999 with the best fit observed for the Langmuir model. The maximum adsorption capacity of the kaolin clay for the annatto dye was obtained at 25°C with 1% of sodium sulphate (q _max = 59.88 mgg^-1).

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Bixin and norbixin protect against DNA-damage and alterations of redox status induced by methylmercury exposure in vivo

Populations in the Amazon are exposed to organic mercury via consumption of contaminated foods. These ethnic groups consume a specific plant seed "annatto" which contains certain carotenoids. The aim of this study was to find out if these compounds (bixin, BIX and norbixin, NOR), protect against DNA-damage caused by the metal. Therefore, rats were treated orally with methylmercury (MeHg) and with the carotenoids under conditions that are relevant to humans. The animals were treated either with MeHg (30 μg/kg/bw/day), BIX (0.1-10 mg/kg/bw/day), NOR (0.01-1.0 mg/kg/bw/day) or combinations of the metal compound and the carotenoids consecutively for 45 days. Subsequently, the glutathione levels (GSH) and the activity of catalase were determined, and DNA-damage was measured in hepatocytes and leukocytes using single cell gel electrophoresis assays. Treatment with the metal alone caused a decrease in the GSH levels (35%) and induced DNA damage, which resulted in increased DNA migration after electrophoresis in liver and blood cells, whereas no effects were seen with the carotenoids alone. When BIX or NOR were given in combination with organic mercury, the intermediate and the highest concentrations of the carotenoids (1.0 and 10.0 mg/kg/bw/day BIX and 0.1 and 1.0 mg/kg/bw/day NOR) protected against DNA-damage. Furthermore, we found with both carotenoids, a moderate increase in the GSH levels in both metal-treated and untreated animals, while the activities of catalase remained unchanged. Our results indicate that consumption of BIX and NOR may protect humans against the adverse health effects caused by exposure to organic mercury.

The chemopreventive effect of Ginkgo biloba and Silybum marianum extracts on hepatocarcinogenesis in rats

Background/objective

This study was designed to evaluate the potential chemopreventive activities of Ginkgo biloba extract (EGb) and Silybum marianum extract (silymarin) against hepatocarcinogenesis induced by N-nitrosodiethylamine (NDEA) in rats.

Methods

Rats were divided into 6 groups. Group 1 served as normal control rats. Group 2 animals were intragastrically administrated NDEA at a dose of 10 mg/kg five times a week for 12 weeks to induce hepatocellular carcinoma (HCC). Groups 3 and 4 animals were pretreated with silymarin and EGb respectively. Groups 5 and 6 animals were posttreated with silymarin and EGb respectively. The investigated parameters in serum are alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltransferase (GGT) and vascular endothelial growth factor (VEGF). The investigated parameters in liver tissue are malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and comet assay parameters.

Results

In NDEA group, MDA level was elevated with subsequent decrease in GSH level and SOD, GPx and GR activities. In addition, NDEA group revealed a significant increase in serum ALT, AST and GGT activities and VEGF level. Furthermore, NDEA administrated animals showed a marked increase in comet assay parameters. These biochemical alterations induced by NDEA were confirmed by the histopathological examination of rat livers intoxicated with NDEA that showed an obvious cellular damage and well differentiated HCC.

In contrast, silymarin+NDEA treated groups (3&5) and EGb+NDEA treated groups (4&6) showed a significant decrease in MDA level and a significant increase in GSH content and SOD, GPx and GR activities compared to NDEA group. Silymarin and EGb also beneficially down-regulated the increase in serum ALT, AST, GGT activities and VEGF level induced by NDEA. In addition, silymarin and EGb significantly decreased comet assay parameters. Histopathological examination of rat livers treated with either silymarin or EGb exhibited an improvement in the liver architecture compared to NDEA group.

Conclusions

The obtained findings suggested that silymarin and EGb may have beneficial chemopreventive roles against hepatocarcinogenesis through their antioxidant, antiangiogenic and antigenotoxic activities.

Expression of placental glutathione S-transferase in rat tongue mucosa exposed to cigarette smoke

Glutatione S-transferases (GSTs) are a family of enzymes involved in detoxification of xenobiotics. Placental GST, known as GST-P, has been detected in tissues following exposure to carcinogenic agents being regarded a reliable biomarker of exposure and susceptibility in early phases of carcinogenesis. The aim of this study was to investigate the expressivity of GST-P positive foci in the rat tongue mucosa exposed to cigarette smoke by means of immunohistochemistry. A total of twelve male Wistar rats were distributed into two groups: negative control and experimental group exposed to cigarette smoke during 75 days. After experimental period, no histopathological changes in the tongue mucosa were evidenced in the negative control and the experimental group. However, a total of five GST-P positive foci were detected in two out of six animals exposed to cigarrette smoke. None control animals were noticed GST-P positive foci. These data indicate that expression of GST-P may reflect the carcinogenic effect of cigarette smoke as well as the genetic susceptibility of animals in relation to continuous carcinogens exposure.

Placental glutathione S-transferase correlates with cellular proliferation during rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide

Taking into consideration that glutatione S-transferase (GST) and cellular proliferation play a crucial role during carcinogenesis, the goal of this study was to investigate the expression of placental GST, called GST-P, and proliferating cellular nuclear antigen (PCNA) by means of immunohistochemistry during rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide (4NQO). This is a useful model for studying oral squamous cell carcinoma phase by phase. Male Wistar rats were distributed into three groups of 10 animals each and treated with 50 ppm 4NQO solution by drinking water for 4, 12 or 20 weeks. Ten animals were used as negative control. GST-P positive foci were detected in non-neoplastic oral cells at 4 weeks of 4NQO administration. In the same way, GST-P positive cells were detected in pre-neoplastic lesions and squamous cell carcinomas induced after 12 and 20 weeks-treatment, respectively. None of the control animals expressed GST-P positive cells. Regarding cellular proliferation, PCNA positive nuclei were higher at 12 and 20 weeks following 4NQO exposure (p<0.05) when compared to negative control. These results suggest that the expression of GST-P is correlated with cellular proliferation, in which GST-P is associated with risk and progression of oral cancer, whereas PCNA is closely involved during neoplastic conversion.

Brazilian natural dietary components (annatto, propolis and mushrooms) protecting against mutation and cancer

Considering the high number of new cancer cases in Brazil (approximately 470000 cases in 2005) and the remarkable differences in the incidence of this disease around the world, the development of chemopreventive strategies using foods widely consumed would have a huge impact, both medically and economically. This review summarizes some of our studies conducted to verify the anti-mutagenic and anti-carcinogenic potential of some Brazilian natural dietary constituents (annatto, mushrooms, and propolis). Overall data have shown a clear role for these compounds in preventing mutation and specific preneoplastic lesions. Taken together, these agents indicate a favorable side-effect profile and may prove to be a promising alternative for cancer prevention strategies, although more investigation is needed to fully explore this issue.