Food Chem Toxicol 2000 Jul;38(7):599-605
Intake of butylated hydroxyanisole and butylated hydroxytoluene and stomach cancer risk: results from analyses in the Netherlands Cohort Study.
Botterweck AA, Verhagen H, Goldbohm RA, Kleinjans J, van den Brandt PA.
Department of Epidemiology, Maastricht University, The Netherlands.
AAM.Botterweck@Epid.unimaas.NL
Both carcinogenic and anticarcinogenic properties have been reported for the synthetic antioxidants butylated hydroxyanisole (BHA) and butylated
hydroxytoluene (BHT). The association between dietary intake of BHA and BHT and stomach cancer risk was investigated in the Netherlands Cohort Study (NLCS) that started in 1986 among 120,852 men and women aged 55 to 69 years. A semi-quantitative food frequency questionnaire was used to assess food consumption. Information on BHA or BHT content of cooking fats, oils, mayonnaise and other creamy salad dressings and dried soups was obtained by chemical analysis, a Dutch database of food additives (ALBA) and the Dutch Compendium of Foods and Diet Products. After 6.3 years of follow-up, complete data on BHA and BHT intake of 192 incident stomach cancer cases and 2035 subcohort members were available for case-cohort analysis. Mean intake of BHA or BHT among subcohort members was 105 and 351 microg/day, respectively. For consumption of mayonnaise and other creamy salad dressings with BHA or BHT no association with stomach cancer risk was observed. A statistically non-significant decrease in stomach cancer risk was observed with increasing BHA and BHT intake [rate ratio (RR) highest/lowest intake of BHA = 0.57 (95% confidence interval (CI): 0.25-1.30] and BHT = 0.74 (95% CI: 0.38-1.43). In this study, no significant association with stomach cancer risk was found for usual intake of low levels of BHA and BHT.
25: Exp Toxicol Pathol 1996 Feb;48(2-3):189-95
Epigenetic carcinogens: evaluation and risk assessment. Williams GM, Whysner J. American Health Foundation, Valhalla, NY 10595-1599, USA.
Regulatory policies in the U.S. have been developed based upon a single model of cancer causation, which assumes chemical-induced genetic alterations. Such a model predicts some degree of cancer risk even at extremely low exposure levels.
Many chemicals that produce tumors in experimental animals have been shown to act by epigenetic mechanisms that do not involve an attack by the chemical on DNA leading to subsequent genetic alteration. Such indirect mechanisms require prolonged exposures to high levels of chemicals for the production of tumors. For chemicals that are carcinogenic in this manner, the cancer mechanism would not be operative at exposures below a threshold at which the relevant cellular effect does not occur. Also, in contrast to DNA-reactive mechanisms, epigenetic
effects may be unique to the rodent species used for testing. Certain chemical tumorigens have been well studied and provide examples for the of mechanistic information in risk assessment. Butylated hydroxyanisole and saccharin are nongenotoxic food additives for which no risk to humans is predicted based upon low exposure levels and the likelihood that humans are either insensitive or much less sensitive to the tumorigenic effects found in rodent test species. For another non-genotoxic food additive d-limonene, the mechanism that underlies kidney tumor development in male rats is not expected to be operative in humans at all. The pharmaceutical phenobarbital represents a large group of non-genotoxic liver microsome enzyme inducers, which produce liver cancer in mice at levels that are near to therapeutic doses in humans.
Epidemiology studies have not shown phenobarbital-related tumors in humans, indicating that humans may be less sensitive to the effects of phenobarbital.
The mechanistic considerations involved in the risk assessment of these agents demonstrate that humans are not at risk from current exposure levels of many epigenetic carcinogens.
Advantages of BHA:
The following articles show that BHA is good for health!
Anticarcinogenic effect on humans
Food Chem Toxicol 1999 Sep-Oct;37(9-10):1027-38
Safety assessment of butylated hydroxyanisole and butylated hydroxytoluene as antioxidant food additives.
Williams GM, Iatropoulos MJ, Whysner J.
Department of Pathology, New York Medical College, American Health Foundation
Valhalla, 10595, USA.
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are widely
used antioxidant food additives. They have been extensively studied for
potential toxicities. This review details experimental studies of genotoxicity
and carcinogenicity which bear on cancer hazard assessment of exposure to humans. We conclude that BHA and BHT pose no cancer hazard and, to the contrary, may be anticarcinogenic at current levels of food additive use.
Anticarcinogenic effect on animals
Food Chem Toxicol 1999 Sep-Oct;37(9-10):985-92
Phenolics: blocking agents for heterocyclic amine-induced carcinogenesis.
Hirose M, Takahashi S, Ogawa K, Futakuchi M, Shirai T.
First Department of Pathology, Nagoya City University, Medical School, Nagoya, Japan.
Chemopreventive effects of synthetic and naturally occurring antioxidants on heterocyclic amine (HCA)-induced rat carcinogenesis and mechanisms of inhibition were assessed. In a medium-term liver bioassay, combined treatment with 0.03% 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and synthetic antioxidants such as 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), butylated hydroxyanisole
(BHA), butylated hydroxutoluene (BHT), tert-butylhydroquinone (TBHQ) or propyl
gallate, each at a dose of 0.25%, inhibited development of preneoplastic
glutathione S-transferase placental form (GST-P) positive foci as compared with
MeIQx alone, after initiation with diethylnitrosamine (DEN). Of these
antioxidants, HTHQ showed the greatest activity. 8-Hydroxydeoxyguanosine
(8-OHdG), a marker for DNA damage induced by active oxygen species, and
malonedialdehyde and 4-hydroxynonenal levels were not largely influenced by the
treatment with MeIQx or antioxidants, either alone or in combination. In the same medium-term liver bioassay, effects of some naturally occurring
antioxidants, such as green tea catechins (GTC), hesperidin, chlorogenic acid, quercetin, rutin, curcumin, daidzin, ferulic acid and genistein were also examined. Of these antioxidants, only GTC tended to inhibit GST-P positive foci development, while quercetin, rutin, curcumin, daidzin, ferulic acid and genistein all exerted significant enhancing effects. Examination of HTHQ influence in a medium term liver bioassay with HCA Glu-P-1, in which the experimental period was extended for up to 26 weeks, also demonstrated a significant decrease in the incidence of liver tumours to 40% in the group treated with 0.5% HTHQ and 0.03%
2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) as compared with the Glu-P-1 alone value of 89%. Effects of HTHQ on colon carcinogenesis induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were evaluated in a
two-stage colon carcinogenesis model using 1,2-dimethylhydrazine (DMH) as an initiator. At week 36, the multiplicity of colon tumours induced by 0.02% PhIP after DMH initiation (9.1+/-6.2/rat) was dose-dependently decreased by the combined treatment with 0.5% HTHQ (3.6+/-1.8, P < 0.001) and 0.125% HTHQ (6.2+/-3.2, not significant). Similarly, the incidence of mammary carcinomas in female F344 rats induced by oral administration of 0.02% PhIP (40%) for 52 weeks was significantly decreased by simultaneous treatment with 0.5% HTHQ (5%).
Alpha-tocopherol and chlorophyllin only reduced the multiplicity of carcinomas.
Analysis of the influence of HTHQ on metabolic activation of Glu-P-1 or PhIP after incubation with rat S9 mixture and NADPH by HPLC, revealed that each major metabolite was strongly reduced by the addition of HTHQ. Immunohistochemically detected PhIP-DNA adduct positive nuclei in the colon induced by continuous oral treatment with 0.02% PhIP for 2 weeks decreased by the combined treatment with 0.5 or 0.125% HTHQ. These results indicate that synthetic antioxidant HTHQ is a very strong chemopreventor of heterocyclic amine (HCA)-induced carcinogenesis
and that depressed metabolic activation rather than antioxidant activity is
responsible for the observed effect.
Cancer Lett 1999 Apr 1;137(2):123-30
Evaluation of butylated hydroxyanisole, myo-inositol, curcumin, esculetin, resveratrol and lycopene as inhibitors of benzo[a]pyrene plus 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis in A/J mice.
Hecht SS, Kenney PM, Wang M, Trushin N, Agarwal S, Rao AV, Upadhyaya P.
University of Minnesota Cancer Center, Minneapolis 55455, USA.
hecht002@gold.tc.umn.edu
The potential activities of butylated hydroxyanisole (BHA), myo-inositol,
curcumin, esculetin, resveratrol and lycopene-enriched tomato oleoresin (LTO) as
chemopreventive agents against lung tumor induction in A/J mice by the tobacco
smoke carcinogens benzo[a]pyrene (BaP) and
4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were evaluated. Groups of
20 A/J mice were treated weekly by gavage with a mixture of BaP and NNK (3
micromol each) for 8 weeks, then sacrificed 26 weeks after the first carcinogen
treatment. Mice treated with BHA (20 or 40 micromol) by gavage 2 h before each
dose of BaP and NNK had significantly reduced lung tumor multiplicity. Treatment
with BHA (20 or 40 micromol) by gavage weekly or with dietary BHA (2000 ppm),
curcumin (2000 ppm) or resveratrol (500 ppm) from 1 week after carcinogen
treatment until termination had no effect on lung tumor multiplicity. Treatment
with dietary myo-inositol (30,000 ppm) or esculetin (2000 ppm) from 1 week after
carcinogen treatment until termination significantly reduced lung tumor
multiplicity, with the effect of myo-inositol being significantly greater than
that of esculetin. Treatment with dietary LTO (167, 1667 or 8333 ppm) from 1
week before carcinogen treatment until termination had no effect on lung tumor
multiplicity. The results of this study demonstrate that BHA is an effective
inhibitor of BaP plus NNK-induced lung tumorigenesis in A/J mice when
administered during the period of carcinogen treatment and that, among the
compounds tested, myo-inositol is most effective after carcinogen treatment.
Toxicol Appl Pharmacol 1995 Nov;135(1):45-57
Induction of phase I and phase II drug-metabolizing enzyme mRNA, protein, and activity by BHA, ethoxyquin, and oltipraz.
Buetler TM, Gallagher EP, Wang C, Stahl DL, Hayes JD, Eaton DL.
Department of Environmental Health, University of Washington, Seattle 98195,
USA.
Various natural and synthetic compounds are known to protect against cancer by
elevating phase II detoxification enzymes. Generally classified as
monofunctional, these inducers are believed to trigger cellular signal(s) that
activate gene transcription through an antioxidant or electrophile response
element (ARE/EpRE) in responsive genes. In contrast, the phase I enzymes of drug
metabolism (cytochrome P450s) are not believed to be induced by monofunctional
inducers and P450 genes have not been found to contain functional ARE/EpREs. In
this study, rats were treated with the monofunctional inducers tert-butylated
hydroxyanisole, ethoxyquin, and oltipraz to study the inducibility of individual
glutathione S-transferase isozymes, NADP(H):quinone oxidoreductase,
gamma-glutamylcysteine synthetase, UDP-glucuronosyl transferase, and cytochrome
P450 enzymes. Hepatic mRNAs were analyzed on Northern blots using gene-specific
oligonucleotide probes for GST Ya1, Ya2, Yc1, Yc2, Yb1, Yb2, and Yf, for UGT
1*06, and for P450 1A1, 1A2, 2B1, 2C11, 3A2, and 4A1. NADP(H):quinone
oxidoreductase and gamma-glutamylcysteine synthetase mRNAs were detected using
cDNA probes. All the phase II detoxification enzymes analyzed, except GST Yf,
were induced by the three monofunctional inducers, suggesting that these genes
may be regulated by a mechanism involving an ARE/EpRE element in their promoter
region. Interestingly, it was found that ethoxyquin was a particularly good
inducer for both members of the P450 2B family, 2B1 and 2B2, and both ethoxyquin
and oltipraz were also capable of modestly inducing P450 1A2 and 3A2. Oltipraz
was found to slightly induce P450 2B2, but not 2B1, at the dose and time
analyzed. Induction of mRNA generally correlated well with induction of protein
levels determined by Western blot and/or enzyme activity measurements for
selected enzymes. The results of this study suggest that many phase II enzymes
may contain ARE/EpRE elements in addition to those confirmed to be regulated by
a mechanism involving ARE/EpRE elements. In addition, it was found that several
P450 enzymes were induced by monofunctional inducers, suggesting a possibility
that some phase I enzymes may also be regulated by a mechanism involving
ARE/EpRE elements.
Food Chem Toxicol 1996 Apr;34(4):327-35
Inhibitory effects of the dietary antioxidants butylated hydroxyanisole and
butylated hydroxytoluene on bronchioloalveolar cell proliferation during the
bleomycin-induced pulmonary fibrosing process in hamsters.
Ikezaki S, Nishikawa A, Enami T, Furukawa F, Imazawa T, Uneyama C, Fukushima S,
Takahashi M.
Division of Pathology, National Institute of Health Sciences, Tokyo, Japan.
The effects of dietary antioxidants on bleomycin (BLM)-induced pulmonary
fibrosis were investigated in Syrian golden hamsters. In addition, the influence
on cell proliferative activity in bronchioloalveolar hyperplastic lesions during
the lung fibrosing process was evaluated in terms of argyrophil nucleolar
organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA). Male
6-wk-old hamsters were divided into six groups. Groups 1-3 were intratracheally
instilled with BLM at a dose of 2.5 U/kg body weight on days 0 and 14, and then
given a diet supplemented with 1% butylated hydroxyanisole (BHA), or 1%
butylated hydroxytoluene (BHT), or basal diet alone for the following 41 days.
Groups 4-6 were given 1% BHA, 1% BHT or basal diet without BLM treatment for the
same time period as that in those of groups 1-3. The mortality rate of animals
in group 1 (BLM/BHA) (one in 20; 5%) was lower than in those of groups 2
(BLM/BHT) (three in 20; 15%) and 3 (BLM alone) (four in 20; 20%). BHA and BHT
treatments significantly inhibited lung weight gains by BLM (P < 0.05).
Histopathologically, both BHA and BHT reduced BLM-induced pulmonary
histopathological changes such as fibrosis, macrophage aggregation and
epithelial proliferation, with a tendency for correlation with accumulation of
type III collagen. In addition, antioxidant treatment significantly lowered the
mean numbers of AgNORs (P < 0.01) and PCNA-labelling indices (P < 0.05) in the
hyperplastic bronchioloalveolar lesions. The results thus indicate that these
antioxidants exert inhibitory effects on proliferation of hyperplastic lesions
associated with lung fibrosis.
Cancer Lett 1998 Jan 9;122(1-2):151-6
Postnatal effect of smokeless tobacco on phytic acid or the butylated
hydroxyanisole-modulated hepatic detoxication system and antioxidant defense mechanism in suckling neonates and lactating mice.
Singh A, Singh SP.
Human Genetics Laboratory, School of Life Sciences, Jawaharlal Nehru University,
New Delhi, India.
The present study evaluates the potential of smokeless tobacco to
translactationally modify the chemopreventive efficacy of phytic acid and
butylated hydroxyanisole (BHA) via modulation of the hepatic xenobiotic
detoxication system and antioxidant defense mechanism in the murine system.
Phytic acid (1000 mg/kg b.w./day) by gavage while BHA (1% w/w) in diet induced a
significant increase in the levels of glutathione-S-transferase (GST), acid
soluble sulfhydryl (-SH), cytochrome b5 (Cyt. b5) and cytochrome P-450 (Cyt.
P-450) in lactating dams and suckling pups. The hepatic levels of GST and -SH
were significantly depressed whereas microsomal Cyt. b5, Cyt. P-450 and MDA
levels were elevated in groups treated with smokeless tobacco (50 or 100 mg/kg
b.w./day). The data reveals the inhibitory potential of smokeless tobacco on
phytic acid-induced GST/GSH system efficiency besides the significant
augmentation by smokeless tobacco on phytic acid or BHA-induced microsomal phase
I enzymes. The direct or translactational modulation in the levels of xenobiotic
detoxication system enzymes suggests the potential of smokeless tobacco to
modify the chemopreventive efficacy of phytic acid or BHA.
J Pharm Pharmacol 1996 Sep;48(9):940-4
Protective effect of butylated hydroxyanisole on adriamycin-induced
cardiotoxicity.
Vora J, Khaw BA, Narula J, Boroujerdi M.
Department of Pharmaceutical Sciences, Northeastern University, Boston, MA
02115, USA.
Adriamycin has a wide spectrum of antitumour activity with dose-related
cardiotoxicity as a major side effect. This cardiotoxicity has been suggested to
result from the generation of oxygen free radicals. The objective of the present
study was to investigate the influence of the antioxidant, butylated
hydroxyanisole co-therapy on the cardiotoxicity of adriamycin, in-vivo. The
aqueous solubility of butylated hydroxyanisole was enhanced by inclusion complex
formation with hydroxypropyl-beta-cyclodextrin. The extent of drug-induced
myocardial damage in rats was assessed using intravenous 111In-labelled
antimyosin Fab and chronological changes in serum creatine kinase levels. There
was a dose-related increase in myocardial antimyosin uptake in rats, which
reached a plateau at an adriamycin dose of 10 mg kg-1. The antimyosin uptake at this dose (% dose g-1 = 0.1942 +/- 0.0150, n =
was significantly reduced by co-administration of butylated hydroxyanisole with adriamycin (10 mg kg-1 of each) to 0.1462 +/- 0.0116 (n = 5, P < 0.05). Assessment of cardiotoxicity in the rats was also performed by measuring serial changes in serum creatine kinase levels. Increasing doses of adriamycin caused an increase in serum creatine kinase levels with peak values obtained between 2 and 8 h after dosing. These values decreased upon co-administration of butylated hydroxyanisole with adriamycin at 10 mg kg-1, each and 30 mg kg-1 each by 29 and 41%, respectively.
On the other hand, butylated hydroxyanisole did not inhibit the tumouricidal activity of adriamycin as investigated in-vitro using the NMU rat mammary
adenocarcinoma cell-line. The significant reduction in anthracycline
cardiotoxicity by butylated hydroxyanisole coadministration may result from its scavenging action on adriamycin-mediated free-radical formation or its enhancement of activity of enzymes involved in the metabolism of adriamycin.
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