Essay: Effect of food azo dyes on liver enzymes

In our study, the increased activities of serum enzymes (AST and ALT) have been detected in food colorants administrated in rats specially at higher doses, implying the increased permeability, damage and injuries of hepatocytes. Because the enzyme ALT is located in the cytoplasm and the soluble enzyme AST is located mainly in organelles such as mitochondria (Senthil et al., 2003). Increased levels of AST and ALT suggested damage of both hepatic cellular and mitochondrial membranes in food azo dyes administered rats.
Rats consumed high dose of tartrazine (500 mg/kg bw) for 30 days or high dose of carmoisine (100 mg/kg bw) exhibited a significant increase in serum ALT, AST and alkaline phosphatase activities when compared to control rats (Table 2), while low dose of carmoisine (8 mg/kg bw) showed a significant increase in serum ALT and alkaline phosphatase activities when compared to control rats. In addition, low dose of tartrazine (15 mg/kg bw) showed a significant increase in serum alkaline phosphatase activity when compared to control rats (Amin et al., 2010).
This findings was in a agreement with Mekkawy et al.(1998) who indicated that two doses of synthetic dyes (low or high doses) where tartrazine and carmoisine were among of them (ponceau, carmoisine, erythrosine, sunset yellow, tartrazine, fast green, indigotine, brilliant blue and brilliant black) showed a significant increase in serum AST, ALT, and alkaline phosphates activities and attributed these results to hepatocellular damage caused by the toxic effects of these synthetic dyes which indicated by vacuolation, swelling, necrosis and pyknosis of the liver cells.
The elevation of aminotransferases activities in serum may be due to tissue damage particularly in liver, kidney and heart and increased permeability of cell membrane or increased synthesis or decreased catabolism of transaminases may be involved.
Another mechanism of the significant elevation of serum aminotransferases may be due to pathological conditions of the parenchymal cells of hepatic lobules and fail to carry out vital functions, which usually results in disturbed or imbalanced intermediary metabolism, as a result of cellular damage, several enzymes like ALT, AST, LDH and ALP beach out into the serum and hence their level indicate the type and extent of damage.
The groups treated with 10 mg/ kg BW of Tartrazine revealed a marked increase in the average liver weight in the experimental groups and severe histological changes in the liver; but congested blood vessels and areas of haemorrhage in the liver did not revealed , the hepatocytes become swollen and a single large vacuole will occupy their entire cytoplasm (Himri et al., 2011). The degenerated hepatocytes form wide trabeculae which compress and narrow the lumen of the sinusoids, also brown pigment deposition in the Küpffer cells and fatty degeneration of the liver in groups treated with 7.5, 10 mg/ (kg BW) of Tartrazine (Himri et al., 2011).
4.6- Effect of Tartrazine on kidney function:
Daily intake for 30 day of tartrazine either low or high doses exhibited a significant increase in serum creatinine and urea concentration when compared with control rats, while high dose of tartrazine exhibited a significant increase more than low dose in serum creatinine level(Amin et al., 2010). These results parallel to those recorded by Helal et al. (2000) who found a significant elevation in serum creatinine and urea in rats consumed a synthetic or natural food colorants after 30 days of treatment. Furthermore, these findings are in accordance with data reported by Ashour and Abdelaziz (2009) who observed a significant elevation in serum creatinine and urea level of rats dosed with organic azo dye (fast green) orally for 35 days. Also Tartrazine exhibited a significant increase in serum Creatinine concentration when compared with control rats in a dose response manner (Himri et al., 2011).
We believe that the significant elevation in urea and creatinine levels is closely related to the impairment of renal function. These results are in agreement with Varely (1987) who determined that the blood urea can be increased in all forms of kidney diseases such as hydronephrosis congenital cystic, kidney renal tuberculosis, condition in which deposition of calcium occurs as hypervitaminosis D. Also plasma creatinine increases in renal diseases gave prognostic significance than those of other nitrogenous substances. Recently the histopathological examination revealed tubular dilatation with thickened basement membrane in group treated with 5 mg/ (kg BW) of Tartrazine, tubular degeneration, and dilatation of the glomerular capillaries in group treated with 7.5 mg/ (kg BW) of Tartrazine, and intercapillary sclerosis, atrophy of glomerulus in group treated with 10 mg/ (kg BW) of Tartrazine (Himri et al., 2011).
For both liver and kidney phenomena represented by stasis and oedema, congestion, hepatocyte and kidney apoptosis, with atrophy of renal corpuscles were observed. Degree and severity of histopathological aspects observed were directly proportional to the concentration of the administered dyes (Rus et al., 2009).
4.7- Effect of food azo dyes (tartrazine and carmoisin) on lipid profile:
The reduction in serum cholesterol levels (Table 2) obtained in the study of Amin et al., (2010) was correlate well with that reported by Ashour and Abdelaziz (2009) who obtained a significant reduction in serum total cholesterol and triglycerides level when food color azo dye (fast green) was consumed orally to male albino rats for 35 days.
Approximately 50% of the intestinal cholesterol pool is reabsorbed by the intestines and recirculated through the body via the enterohepatic circulation, with the remainder excreted in feces. The deviation from normal values of cholesterol, in the blood serum is considered as symptoms of liver diseases and so, the decreased cholesterol level may implies liver injuries.
4.8- Effect of food colorants (azo dyes) on antioxidant/oxidative stress biomarkers:
The work of Amin et al., (2010) revealed that rats consumed high and low doses of carmoisine and that consumed high dose of tartrazine (Table 2) showed a significant decrease in liver GSH content and catalase activity. Also high and low doses of tartrazine and high dose of carmoisine showed a significant decrease in liver SOD activity when compared to control group, while high and low doses of carmoisine and high dose of tartrazine showed a significant increase in liver MDA. Increased generation of ROS or free radicals is able to cause auto-oxidation of the hepatic cells, resulting in marked hepatic lesions resulting in release of hepatic function enzymes ALT and AST.
Tartrazine, could be regarded as toxic due to its possible oxidative impairment induced by depletion of GSH, the main antioxidant for the cell, and a significant increase in MDA levels, where the researchers strongly trust that the usage of these possibly toxic colors in food requests to be re-evaluated (Demirkol et al., 2012).
In a recent study Mohamed et al., (2015) reported that tartrazine an extensively used synthetic azo dye induced a sharp shortage in the antioxidant biomarkers (super oxide dismutase, catalase and the reduced glutathione) and a marked rises in malondialdehyde concentration in the brain cortex compared with the other groups male rat pups.
We suggest a potential role for commonly consumed beverages in elevating the risk of pathophysiology associated with peroxyl radical-mediated events. A healthy food consists of real food, without any artificial additives and high-quality food has no need of Tartrazine or any artificial color.
4.9. Effect of tartrazine in nervous system, hyperactivity and behaviour:
The dose levels of 125-500 mg/kg giving for 30 days of tartrazine produced a few adverse effects in learning and memory functions in animals. The mechanisms might be attributed to promoting lipid peroxidation products and reactive oxygen species, inhibiting endogenous antioxidant defense enzymes and the brain tissue damage (Gao et al., 2011). Taken together, because of the current evidence presented, the daily consumption of Tartrazine as agreed by the ADI rate seems to be reasonably harmless, however exposure is unlikely to be reached after ingestion of food.
Tartrazine induced hyperactivity, anxiety and anti-social behaviour among male Wistar rats in doses of 0, 1 and 2.5% in drinking water as measured by the different animal models of open field, elevated plus-maze and the dark-light transition tests (Kamel and El-lethey 2011).
Moreover, Tanaka et al., (2008) found that, the dose levels of tartrazine (0.05%, 0.15%, and 0.45%) produced a few adverse effects on neurobehavioral parameters throughout generations in mice. The dose level of tartrazine produced a few adverse effects in neurobehavioural parameters during the lactation period in mice (Tanaka 2006).
In a clinical study a mixture of sunset yellow, carmoisine and tartrazine have been used to examine their effect on 3- 8/9-year-old children behavior and found that, Synthetic colours in the diet result in intensify the hyperactive behaviours (inattention, impulsivity, and overactivity) in children at least up to middle childhood. Increased hyperactivity is accompanied with the progress of educational problems, particularly in relation to reading, and so could affect the child’s skill to benefit from the experience of schooling (McGee et al., 2002). These results show that adverse properties are not just seen in children with extreme hyperactivity,4 but can also be seen in the general population and across the range of severities of hyperactivity (McCann et al., 2007).
In a more recent experimental study tartrazine evaluated for the potential neurotoxic effect, where it showed, a significant decrease in the brain neurotransmitters (gamma amino butyric acid, dopamine and serotonin) and numerous apoptotic cells in the brain cortex using an immunohistochemical staining of the cerebral cortex with the anti-ssDNA antibody (an apoptotic cell marker) compared to the other groups (Mohamed et al., 2015)
4.10. Effect of tartrazine in DNA and as carcinogenic:
To answer the question, is Tartrazine has carcinogenic properties, different concentrations of the dye, ranging from 0.25-64.0 mM demonstrated that tartrazine has no cytotoxic effects. However, this dye had a significant genotoxic effect at all concentrations tested. Although most of the damage was amenable to repair, some damage remained higher than positive control after 24 h of repair. These data demonstrate that tartrazine may be harmful to health and its prolonged use could trigger carcinogenesis (Soares et al., 2015).
Spectroscopic titration studies for the interaction of tartrazine food additives with DNA showed that these dyes bind to calf thymus DNA and distinct isosbestic points are observed clearly suggesting binding of the dyes to DNA. food colorants tartrazine had a toxic potential to human lymphocytes in vitro and it seems that they bind directly to DNA (Mpountoukas et al., 2010). In a novel study, the interaction of tartrazine and endogenous compound as bovine haemoglobin was defined in the dye (Li et al., 2014).
We could determine that the extensive DNA damage in the colon and the glandular stomach at doses higher than 10 mg/kg b.w. observed by Sasaki et al. (2002) could be due to the acute cytotoxicity of the dye. It could also be due to insufficient DNA repair at the 3 h sampling time. while Poul et al., (2009) verified the non-mutagenicity of tartrazine when giving orally up to doses of 2000 mg/kg b.w. and reported that the dye at any of the examined doses not increase quantity of micronucleated colonic cells compareing with control groups.
Studies about tartrazine genotoxic, cytotoxic and mutagenic effects are controversial and, in some cases, unsatisfactory. In this concern, the work of Soares et al., (2015) demonstrated that tartrazine has no cytotoxic effects. However, the dye had a significant genotoxic influence at concentration of 0.25-64.0 mM. Although most of the damage was amenable to repair, some damage remained higher than positive control after 24 h of repair and concluded that tartrazine may be harmful to health and its prolonged use could trigger carcinogenesis.
On the other hand infrequent studies indicated that tartrazine, indigo carmine and erythrosine are potent inhibitors of skin tumor promotion in mice treated with DMBA and TPA (Kapadia et al. 1998) .
Long term carcinogenicity of tartrazine:
Some literature are now available on the chronic effect of tartrazine. Himri et al., (2011) found that a 90 daily oral dosing of 5, 7.5 and 10 mg/kg b.w in Wistar rats, showed significant dose-related increase in blood biochemical markers of glucose, creatinine, blood urea nitrogen, total cholesterol, total protein, triglycerides and AST comparing with the control.
When tartrazine was giving at doses of 0, 1 and 2% in the drinking water of groups of 50 male and female rats for 2 years, carcinogenicity was absent (Maekawa et al., 1987). There were nontoxic injuries were reported in the treated groups at any of the dye doses. The tumours observed, in the treated and control groups, were spontaneous in this strain of rats and the authors determined that the tumours that was observed in the 1% treated group is not related to the dye administration.
Collectively, these records revealed that Tartrazine might generate carcinogenesis at a extraordinary dose or accumulative exposure, however this is improbable to be happen.
4.11. Reproductive and developmental toxicity of tartrazine:
Tartrazine did not produce any significant teratogenic toxic effect in of dose levels of 0, 60, 100, 200, 400 and 600 mg/kg b.w in pregnant Osborne-Mendel within the first 19 days of pregnancy (Collins et al., 1990, 1992). Meanwhile, Mehedi et al. (2009) recorded the toxicity of tartrazine on the reproductive organs including, reduced sperm count and increased incidence of sperm abnormalities and reduction in reproductive performance in mice with doses of 0, 0.1, 1.0 and 2.5% 13 weeks.
There are particular clinical studies designed to assess effects of various colorant mixtures, as they may be consumed in ordinary life (McCann et al., 2007). Regrettably, these works have many limitations; hence it is difficult to determine a clear conclusion on the matter (Amchova et al., 2015). The choice of a certain method for evaluating a food additive compounds can based on its chemistry, expected mechanism of action and also, there is need for constant evaluation of new chemicals and existing ones as well, because of the often contradicting results and insufficient data to conclusively categorize many routinely used substances as safe or carcinogenisity.
4.12. Effect of tartrazine on tissues Bioelement Contents:
In a few manuscript dealing with biolement and tartrazine we have found a literature reported a some significant changes on levels of bioelements in rats’ liver, kidney and brain tissues exposed to the tartrazine (cemek et al 2014). The changes include increased Cu and iron level in renal tissue, which is important because copper accumulation in the tissues leads to Wilson’s disease and hepatic cirrhosis (Shazia et al., 2012), this effect is may be due to binding of Copper and iron to the artificial food colorants resulting in its tissues accumulation (Stevens et al., 2013).
The levels of the trace elements, Aluminium and barium reduced by consuming high and low dose tartrazine in brain. Moreover low dose tartrazine induced reduce liver zinc content and high dose tartrazine has the same result in kidney, this may be because of unsaturated fatty acids peroxidation in cell membranes by ROS produced during tartrazine administration resulted in a decrease of membrane flexibility and disturbance in cell function and integrity which affected the pumping and selecting activities of membranes and the level of bioelements may be altered in tissues (Cemek et al 2014).
5. Conclusion and recommendations:
From the previous literature accumulating evidence indication various harmful role of tartrazine on several organs and health systems.
In nutrition the probability of toxicity in chemical compounds means all new are to be regarded as toxic until their safety is confirmed.
The choice of a certain method for evaluating a food additive compounds can based on its chemistry, expected mechanism of action and also, there is need for constant evaluation of new chemicals and existing ones as well, because of the often contradicting results and insufficient data to conclusively categorize many routinely used substances as safe or carcinogenic,
1-Food additives like, colorants tartrazine affect adversely and alter biochemical markers in vital organs e.g. liver and kidney not only at higher doses but also at low doses. Egyptian children consume these additives several times daily in chocolates, gum, chips, drinks, and a lot of products that contain these food additives.
2-Tartazine as food additives not only cause changes in hepatic and renal parameters (urea and creatinine) but also their effect become more risky at higher doses when consumed daily for 30 days, because they can induce hepatic oxidative stress by formation of free radicals, tartrazine can converted by intestinal flora into aromatic amines that may be converted to nitrosamine then releasing ROS (reactive oxygen species). Therefore, it is necessary to create consumer awareness regarding the ill effects of these food azo dyes
3-Many companies that produce products containing these food additives didnot mention the type or concentration of food additive added to their products, so population cannot determine the type of food additive or dose that, they consumed.
4-The given food additives can affect the growth of children and may lead to loss of body weight, this may due to reduction of food consumption. Also carmoisine and tartrazine are from the azo dye group and they cause hypersensitivity and allergic reactions. We advice that tartrazine and carmoisine must be restricted from use as food additives from foods especially consumed by young children and we must try to find other additives that may less toxic than those additives and not induce hypersensitivity and evaluate their effect before use.
5- We recommended updating the safety evaluation with modern methodological approaches and addition of recently published data including results from studies on body organs injuries, genotoxicity, chronic toxicity/carcinogenicity and reproductive toxicity.
6- Finally we advice the companies of food industries to mention the name and concentration of food additives that found in their products especially those are mostly consumed by young children and give attention in their labels to offer clear and important information to intolerant persons.
Updated cumulative evidences have been increased indicating the potential harmfull of tartrazine beside its useless as nutritive additive, our advice as researcher is to avoid it use.
Conflict-of-interest statement: There were no conflict of interest