The dose-dependent effect of BHT (butylated hydroxytoluene) on vitamin K-dependent blood coagulation in rats

Ethanol extract of mango seed is a suitable plant-based replacement for synthetic antioxidants in pig grower–finisher diets

The objective of the present study was to evaluate the inclusion of ethanol extracts of mango seed (EEMS) in growing–finishing pig diets on lipid stability and antioxidant potential of feed, animal performance, carcass traits as well as haematological and biochemical parameters in the serum. Thirty-two barrows that were 60 days old and weighed 20.20 ± 1.34 kg were used in a randomised-block design with four treatments and eight replicates. The treatments consisted of the following: diet without antioxidant addition (negative control); diet with 200 mg of butylate hydroxytoluene/kg (positive control); diet with 200 mg EEMS/kg (EEMS200); and diet with 400 mg EEMS/kg (EEMS400). Diet with synthetic (butylate hydroxytoluene) and natural antioxidants presented better oxidative stability and antioxidant potential than did the negative control. Animals fed 400 mg EEMS/kg presented greater weight gain up to 110 days (P < 0.05). Pigs fed diet containing 200 mg EEMS/kg showed a decrease in red blood cells (P < 0.001) and a higher average corpuscular volume (P < 0.0001), whereas pigs fed control diet had lower average corpuscular haemoglobin concentration than did those in other treatments (P < 0.01). At 140 days of age, dietary addition of 400 mg EEMS/kg decreased malondialdehyde and increased antioxidant potential (2,2-diphenyl-1-picryl hydrazyl method) in serum, with the highest phenolic compound concentration found in the serum of pigs fed diet with 200 mg EEMS/kg. The total antioxidant activity in the serum was not influenced by the treatments (P > 0.05). Ethanol mango extracts can be used as an antioxidant in growing–finishing pig diets at levels of 200 and 400 mg/kg without impairment of performance, carcass traits, serum and biochemical parameters. The dietary addition of EEMS at 400 mg/kg improves the performance of pigs at growing phase and contributes to an increase in circulating phenolic compounds, improving the lipid stability and the antioxidant potential of the serum.

Battery of tests for profiling abnormalities of vitamin K-dependent coagulation factors in drug-toxicity studies in rats

A battery of simple tests for profiling abnormalities of vitamin K-dependent coagulation factors encountered in drug-toxicity studies was verified in rats treated with warfarin (3 and 10 mg/kg, p.o). The thrombotest, or hepaplastin-test, is useful as a follow-up test after routine screening tests for coagulation abnormalities based on PT and APTT, to rule out other coagulation-factor abnormalities. Measurement of coagulation factor activities (factors II, VII, IX and X) using factor-deficient human plasmas provides direct evidence of decreased activities of vitamin K-dependent factors. Furthermore, Echis carinatus venom coagulation time, together with factor II activity, allows us to confirm the generation of PIVKA-II.

Effects of blood product storage protectants on blood coagulation1 1The opinions expressed herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or the Department of Defense

The ever-increasing demand for blood products challenges scientists to develop new and more effective techniques for their preservation. The progress of these novel preservation technologies uses a wide variety of cryoprotectant, lyoprotectant, and other preservatives, which will need to be explored and assessed for their biological effects during blood product formulation. The leading factor in protectant selection is for their ability to provide superior preservation for a particular blood product. We believe that such protectants used in blood product development should also be evaluated for their ability to preserve normal hemostasic mechanisms. In this review, high-molecular-weight cryoprotectants, lyoprotectants, polyols, amino acids, antioxidants, and surfactants, used because of their protective properties, were evaluated for their possible role in relation to their effect on normal hemostatic mechanisms.

Final report on the safety assessment of BHT(1)

BHT is the recognized name in the cosmetics industry for butylated hydroxytoluene. BHT is used in a wide range of cosmetic formulations as an antioxidant at concentrations from 0.0002% to 0.5%. BHT does penetrate the skin, but the relatively low amount absorbed remains primarily in the skin. Oral studies demonstrate that BHT is metabolized. The major metabolites appear as the carboxylic acid of BHT and its glucuronide in urine. At acute doses of 0.5 to 1.0 g/kg, some renal and hepatic damage was seen in male rats. Short-term repeated exposure to comparable doses produced hepatic toxic effects in male and female rats. Subchronic feeding and intraperitoneal studies in rats with BHT at lower doses produced increased liver weight, and decreased activity of several hepatic enzymes. In addition to liver and kidney effects, BHT applied to the skin was associated with toxic effects in lung tissue. BHT was not a reproductive or developmental toxin in animals. BHT has been found to enhance and to inhibit the humoral immune response in animals. BHT itself was not generally considered genotoxic, although it did modify the genotoxicity of other agents. BHT has been associated with hepatocellular and pulmonary adenomas in animals, but was not considered carcinogenic and actually was associated with a decreased incidence of neoplasms. BHT has been shown to have tumor promotion effects, to be anticarcinogenic, and to have no effect on other carcinogenic agents, depending on the target organ, exposure parameters, the carcinogen, and the animal tested. Various mechanism studies suggested that BHT toxicity is related to an electrophillic metabolite. In a predictive clinical test, 100% BHT was a mild irritant and a moderate sensitizer. In provocative skin tests, BHT (in the 1% to 2% concentration range) produced positive reactions in a small number of patients. Clinical testing did not find any depigmentation associated with dermal exposure to BHT, although a few case reports of depigmentation were found. The Cosmetic Ingredient Review Expert Panel recognized that oral exposure to BHT was associated with toxic effects in some studies and was negative in others. BHT applied to the skin, however, appears to remain in the skin or pass through only slowly and does not produce systemic exposures to BHT or its metabolites seen with oral exposures. Although there were only limited studies that evaluated the effect of BHT on the skin, the available studies, along with the case literature, demonstrate no significant irritation, sensitization, or photosensitization. Recognizing the low concentration at which this ingredient is currently used in cosmetic formulations, it was concluded that BHT is safe as used in cosmetic formulations.

Hazard characterisation of chemicals in food and diet. dose response, mechanisms and extrapolation issues

Hazard characterisation of low molecular weight chemicals in food and diet generally use a no-observed-adverse-effect level (NOAEL) or a benchmark dose as the starting point. For hazards that are considered not to have thresholds for their mode of action, low-dose extrapolation and other modelling approaches may be applied. The default position is that rodents are good models for humans. However, some chemicals cause species-specific toxicity syndromes. Information on quantitative species differences is used to modify the default uncertainty factors applied to extrapolate from experimental animals to humans. A central theme for extrapolation is unravelling the mode of action for the critical effects observed. Food can be considered as an extremely complex and variable chemical mixture. Interactions among low molecular weight chemicals are expected to be rare given that the exposure levels generally are far below their NOAELs. Hazard characterisation of micronutrients must consider that adverse effects may arise from intakes that are too low (deficiency) as well as too high (toxicity). Interactions between different nutrients may complicate such hazard characterisations. The principle of substantial equivalence can be applied to guide the hazard identification and hazard characterisation of macronutrients and whole foods. Macronutrients and whole foods must be evaluated on a case-by-case basis and cannot follow a routine assessment protocol.

Effect of butylated hydroxytoluene on alpha-tocopherol content in liver and adipose tissue of rats

Female rats were fed an antioxidant supplemented diet containing butylated hydroxytoluene (BHT; 0.5% and 1.0%) with or without vitamin E acetate (0.4%) for 4 weeks, after which the contents of BHT and alpha-tocopherol in the liver and abdominal adipose tissue were analysed. The body weight gain was similar in all groups independent of the diet after the first week of treatment. At the end of the experiment the liver weights of the BHT-supplemented rats were increased compared to the liver weights of the control groups, and this difference was unaffected by vitamin E treatment. The liver concentration of alpha-tocopherol was decreased and inversely proportional to the BHT concentration in the diet. This attenuating effect of BHT on the hepatic alpha-tocopherol concentration was present both in animals with and without vitamin E supplementation. In contrast, BHT treatment did not alter the concentration of alpha-tocopherol in abdominal adipose tissue. The results show that BHT has adverse effects in the liver. BHT is metabolized by the cytochrome P450 system in the liver and may be converted to prooxidative compounds during this process. Adipose tissue lacks the cytochrome P450 system. Therefore, the decreased hepatic concentration of alpha-tocopherol may be a consequence of a BHT-induced, free oxygen radical mediated, depletion of this antioxidant.