[CANCER RESEARCH 49, 5784-5788, November 1, 1989]

Effect of Dietary Tannic Acid on Epidermal, Lung, and Forestomach PolycyclicAromatic Hydrocarbon Metabolism and Tumorigenicity in Sencar Mice1

Mohammad Athar,2 Wasiuddin A. Khan, and Hasan Mukhtar3

Department of Dermatology, University Hospitals of Cleveland, Case Western Reserve university, and Veterans Administration Medical Center, Cleveland, Ohio 44106

ABSTRACT

Tannic acid inhibits the mutagenicity of several polycyclic aromatichydrocarbons (PAHs) and their bay-region diol-epoxides. Our priorstudies have shown that when applied topically to Sencar mice, tannicacid caused substantial inhibition of epidermal PAH metabolism, subsequent PAH-DNA adduct formation, and PAH-induced skin tumorigene-sis (H. Mukhtar et al., Cancer Res., 48:2361-2365,1988, and referencestherein). In this study the effects of tannic acid supplementation in thediet (1%, w/w, in AIN-76 diet) of Sencar mice on benzo(a)pyrene (BP)metabolism and its subsequent DNA binding and tumorigenesis in lungand forestomach were evaluated. Animals receiving a tannic acid-containing diet showed diminished aryl hydrocarbon hydroxylase and 7-ethoxy-resorufin 0-deethylase activities in the forestomach and lung. Elevatedglutathione S-transferase and NAD(P)H:quinone reducíaseactivitieswere observed in these tissues. Maximum effects occurred after 45 daysof feeding. Administration of [3H]BP p.o. to animals resulted in lower

covalent binding to DNA in forestomach and lung of animals receivingtannic acid-containing diet as compared to animals receiving AIN-76control diet. Tumor induction studies in forestomach and lung revealedsignificant protection against BP-induced tumorigenesis in animals fedtannic acid-supplemented diet as compared to animals fed control diet.The mice fed tannic acid-supplemented diet developed 3.3 forestomachtumors/mouse compared to 5.2 tumors/mouse in animals receiving controldiet. The numbers of pulmonary tumors per mouse in animals fed tannicacid-supplemented diet and control diet were 1.6 and 3.1, respectively.Topical application of 7,12-dimethylbenz(a)anthracene to animals fedtannic acid-supplemented diet did not result in significant protectionagainst skin tumorigenesis. However, a slight delay in the onset of skintumor formation occurred in tannic acid-fed animals when compared toanimals receiving control diet. Our data suggest that dietary supplementation with tannic acid affords protection against BP-induced forestomachand lung tumorigenesis in rodents.

INTRODUCTION

In recent years, there has been a growing interest in identifying naturally occurring minor dietary constituents capable ofprotecting against the development of some forms of cancer(1-6). In this regard several plant phenols have been shown toinhibit the mutagenicity and/or tumorigenicity of severalPAHs4 and their bay-region diol-epoxides (7-11). Our previous

studies have shown that topical application of several plantphenols to murine skin inhibits PAH metabolism, PAH-DNAadduct formation, and skin tumorigenicity (11-14). In thesestudies, of all the plant phenols tested, tannic acid was shownto possess the most protective effects. Since tannic acid isusually consumed in the diet, it was considered important to

Received 12/15/88; revised 6/9/89; accepted 7/26/89.The costs of publication of this article were defrayed in part by the payment

of page charges. This article must therefore be hereby marked advertisement inaccordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1This study was supported by NI H Grant ES-1900. by American Institute forCancer Research Grant 86A61, and by research funds from the Veterans Administration.

2 Present address: Industrial Toxicology Research Centre, Lucknow, India.3To whom requests for reprints should be addressed, at Veterans Administra

tion Medical Center. 10701 East Boulevard. Cleveland, OH 44106.4 The abbreviations used are: PAH, polycyclic aromatic hydrocarbon; BP,

benzo(a)pyrene; P-450, cytochrome P-450; AHH, aryl hydrocarbon hydroxylase;ERD, 7-ethoxyresorufin O-deethylase; GST, glutathione 5-transferase; QR,NAD(P)H:quinone reducíase;DMBA, 7.12-dimethylbenz(a (anthracene; i.g., in-tragastrically.

study its protective effect when part of the diet. In this studywe assessed the effect of dietary supplementation of tannic acidon PAH-metabolizing enzymes, subsequent binding of PAHmetabolites to DNA, and tumorigenicity in the skin, forestomach, and lung of Sencar mice. Our data show that addition oftannic acid to the diet of Sencar mice affords protection againstBP-induced forestomach and lung tumorigenesis.

MATERIALS AND METHODS

Chemicals. Gold label BP, resorufin, and tannic acid were obtainedfrom Aldrich Chemical Co. (Milwaukee, WI). 7-Ethoxyresorufin waspurchased from Pierce Chemicals. NADPH, NADH, protease (typeXI), /n-cresol, 8-hydroxyquinoline, calf thymus DNA (type I), RNaseA (type II-A), 2,6-dichlorophenolindophenol, l-chloro-2,4-dinitroben-zene, and bovine serum albumin were obtained from Sigma ChemicalCo. (St. Louis, MO). [G-3H]BP (specific activity, 25 Ci/mmol) waspurchased from Amersham Searle (Chicago, IL). Prior to use, radiola-beled BP was purified first on a silica gel (Partisi! 10 ¿im;WatersAssociates) column with hexane as the eluting solvent and subsequentlyby reverse-phase high-performance liquid chromatography using aDuPont Zorbax octadecylsilane column (76.2 mm x 25 cm) eluted withmethanol:water (19:1, v/v). The purity of BP was >99% as judged byhigh-performance liquid chromatography. All other chemicals wereobtained in the purest form commercially available.

Diet and Animals. Six-week-old female Sencar mice, obtained fromthe NCI-Frederick Cancer Research Facility, Bethesda, MD, were usedin this study. Tannic acid-supplemented diet was custom prepared byICN Biochemicals, Cleveland, OH, by mixing 1%, w/w, tannic acid inAIN-76 semipurified diet. AIN-76 semipurified diet was used as thecontrol diet. Both diets were obtained in pellet form.

Treatment of Animals for Metabolic Studies. On arrival in our animalfacility the animals were fed AIN-76 semipurified diet for 7 days afterwhich they were divided into two groups. One group of animals continued receiving this diet whereas the animals of the other group wereshifted to tannic acid-supplemented diet. A close estimate of the dietconsumption was monitored by twice weekly weighing of the uncon-sumed feed. Both groups of animals consumed between 4.5 and 5.5 gof diet per day. Thus each animal on tannic acid-supplemented dietconsumed approximately 50 mg tannic acid per day. The mice wereweighed weekly during the course of the experiment. No significantdifferences in weight gain occurred in the two groups of animals.Furthermore, none of the animals receiving tannic acid-supplementeddiet showed any signs of toxicity. Animals were withdrawn at 0, 30, 45,60, and 90 days of feeding; shaved with electric clippers; and decapitatedwith surgical scissors. Lung, forestomach, and epidermis were removed,cleaned free of blood and extraneous material, and processed for thepreparation of cytosol and microsomes.

Preparation of Microsomal and Cytosolic Fractions. Forestomach,lung, and epidermal microsomal and cytosolic fractions were preparedaccording to established procedures described earlier (13). The cytosolicfractions were stored at —¿�80°Cuntil use and the microsomal pellets

were overlaid with buffer A [100 HIMpotassium phosphate, pH 7.4,containing 10 mM dithiothreitol, 10 IHMEDTA, and 20% (v/v) glycerol]and frozen at -170°C under liquid nitrogen. For the determination of

microsomal enzyme activities the frozen pellets were thawed slowly(within 3-5 days of tissue preparation) in an ice bucket and used as theenzyme source. Enzyme activities were stable under these storageconditions for at least 3 weeks.

Enzyme Assays. AHH activity was determined by a modification ofthe method of Nebert and Gelboin (15), the details of which have been

5784

Research. on August 14, 2021. © 1989 American Association for Cancercancerres.aacrjournals.org Downloaded from

TANNIC ACID PROTECTION AGAINST PAH TUMORIGENESIS

described earlier (12). The quantitation of phenolic BP metabolites wasbased on comparison of fluorescence with a 3-hydroxy-BP standard.ERD activity was determined by a modification of the method of Pohland Fouts (16) as described earlier (12). GST activity was assayed withl-chloro-2,4-dinitrobenzene as substrate as described previously (17).QR activity was determined according to the method described byBenson et al. (18), the details of which were described earlier (19).Protein was determined after precipitation with trichloroacetic acid bythe procedure of Lowry et al. (20), using bovine serum albumin asreference standard.

In Vivo |'H|BP-DNA Binding Studies. For in vivo [3H]BP-DNA

binding studies in epidermis after 45 days of feeding, the mice fromgroups of animals fed control and tannic acid-supplemented diets wereshaved and treated with a single topical application of 5 nmol of | 'II|-BP (100 /iCi) as described earlier (13). For forestomach and lung [3H]-

BP-DNA-binding studies, the animals were given 5 nmol (100 ^Ci) of[3H]BP i.g. as described by loannou et al. (21). The animals were killed

by cervical dislocation 24 h after treatment and the desired tissues wereremoved, cleaned free of extranus material, and homogenized as described earlier (13).

DNA Extraction and Estimation of Covalent Binding. The DNA fromminced tissue homogenates was extracted essentially as described byKates and Beeson (22), with an additional incubation step using protease K (0.5 mg/ml). A second extraction was performed using Kirby's

phenol (23) before precipitation with cold 100% ethanol. ExtractedDNA was then digested with RNase A (1000 units/ml), washed 3 timeswith acetone, and dried under a stream of nitrogen. Purified DNA wasthen dissolved in a suitable volume of 0. l M sodium chloride, pH 7.0,and estimated by measuring its absorption at 260 nm. The purity ofthe DNA was assessed by the absorbance ratios AnufAvu,* 1.98 and-4260^2»* 2.21 (13). Aliquots were counted on a Packard Tri-Carb460 CD liquid scintillation spectrometer to determine the amount of[3H]BP bound to DNA.

Treatment of Animals for Tumor Studies. The efficacy of tannic acid-supplemented diet was evaluated against DMBA-induced skin minorigenesis and BP-induced lung and forestomach tumorigenesis in femaleSencar mice. For this, mice were divided into two groups. One groupof animals was fed control diet and the other group was fed tannic acid-supplemented diet and water ad libitum for 45 days prior to tumorinduction. The selection of 45-days was based on metabolic studiesdetermining when maximum inhibitory effects occurred.

Skin Tumorigenesis. For skin tumorigenesis, after 45 days of eatingthe diet, animals from each group were shaved with electric clippers.In each group 30 animals were used and tumors were initiated by asingle topical application of DMBA (10 ¿tgin 0.2 ml acetone) asdescribed earlier (14). Ten days later tumor promotion was achieved bytwice weekly applications of 12-O-tetradecanoylphorbol-13-acetate(3.24 nmol in 0.2 ml acetone) for 16 weeks. All mice were shifted tocontrol diet on the first day of promotion and were fed the same dietuntil the end of the experiment. The incidence of tumor was observedand recorded weekly as described earlier (14).

Forestomach Tumorigenesis. For forestomach tumorigenesis 30 micefrom each group were given BP (40 mg/kg) in 0.2 ml of corn oil byintubation p.o. twice weekly for 4 weeks. Since in this study we wereinterested in evaluating antiinitiating activity of tannic acid supplementation in the diet, at the end of the fourth week the animals wereswitched to the control diet which was fed until the termination of theexperiment. Thirty-six weeks after the administration of the first doseof BP the mice were sacrificed and autopsied. The stomachs were fixedin an expanded state produced by i.g. injection of 10% buffered formalinand split longitudinally, and tumors of the forestomach were countedunder a dissecting microscope as described by Wattenberg (24). Tumors1 mm or larger were recorded and verified histologically.

Lung Tumorigenesis. For lung tumorigenesis, 30 mice from eachgroup received a single i.p. injection of BP (100 mg/kg) in 0.2 ml ofcorn oil. On the same day all mice were shifted to the control dietwhich was fed until the termination of the experiment. Thirty-six weeksafter BP administration, the animals were killed and lungs were removed and examined under a dissecting microscope. Pulmonary ade

nomas on the surface of the lung were counted grossly and verifiedhistologically as described by Shimkin (25).

RESULTS

Effect of Dietary Tannic Acid on Enzyme Activities. It isbelieved that BP requires metabolism by sequential reactionscatalyzed by cytochrome P-450 and epoxide hydrolase to BPdiol-epoxide I which interacts with the target tissue DNA toinitiate tumorigenesis (26). Therefore, inhibition of the activities of the specific enzymes responsible for the metabolism ofBP might lead to diminished carcinogenic response in targetorgans. The effect of feeding tannic acid-supplemented diet tomice on microsomal AHH and ERD activities in forestomachand lung is shown in Figs. 1 and 2, respectively. Feeding oftannic acid to mice resulted in substantial lowering of AHHand ERD activities in lung and forestomach. Greater inhibitoryeffects were observed in the forestomach than in the lung. Themaximum depletion of enzyme activities in forestomach wasobserved after 45 days of feeding and persisted up to 60 days.In lung, however, the enzyme activities showed a gradual normalizing trend.

The enzymes GST and QR play an important role in thedetoxification and/or elimination of carcinogenic intermediatesof PAHs (17, 27). The effect of tannic acid-supplemented dieton forestomach and pulmonary GST and QR activities in miceis shown in Figs. 1 and 2. Feeding of tannic acid significantlyinduced GST and QR activities in forestomach while no effect

20

30 60

Days on Test Diet90

Fig. 1. Effect of feeding 1% tannic acid-supplemented diet to Sencar mice onenzyme activities in lung. Each value represents the mean of at least threedeterminations. Bars, SEM. For each determination 4 animals were pooled.

120 -

A

20 -

30 60Days on Test Diet

Fig. 2. Effect of feeding 1% tannic acid-supplemented diet to Sencar mice onenzyme activities in stomach. Each value represents the mean of at least threedeterminations. Bars. SEM. For each determination 4 animals were pooled.

5785

Research. on August 14, 2021. © 1989 American Association for Cancercancerres.aacrjournals.org Downloaded from

TANNIC ACID PROTECTION AGAINST PAH TUMOR1GENESIS

could be observed in lung. The maximum induction in enzymeactivities was observed 30 days after feeding which persisteduntil day 90. Feeding of tannic acid in diet did not result inappreciable change in any of the enzyme activities in epidermis(data not shown).

Effect of Feeding Tannic Acid in Diet on [3H]BP Binding to

DNA. It is believed that covalent interactions of BP metaboliteswith DNA are responsible for initiation of their carcinogenicresponse (13, 26). In further experiments, the effect of dietarytannic acid supplementation on covalent binding of [3H]BP to

epidermal, forestomach, and pulmonary DNA was assessed.Feeding of tannic acid in diet significantly reduced covalentbinding of [3H]BP p.o. to forestomach and pulmonary DNA

(Table 1). In epidermis there was no difference between the twogroups of animals in covalent binding of topically applied[3H]-BP to DNA.

Effect of Feeding Tannic Acid in Diet on Forestomach Tumor-igenesis. The effect of feeding tannic acid-supplemented diet onBP-induced forestomach neoplasia is shown in Table 2. Feedingof tannic acid-supplemented diet to mice prior to tumor initiation resulted in a significant decrease in the number as well asin the incidence of forestomach tumors. In animals fed controldiet and tannic acid-supplemented diet, the number of tumorsper mouse were 5.2 ±0.7 and 3.3 ±0.6, respectively. Histológica! examination showed that the tumors in both the groupswere benign papillomas. Tumors in animals receiving controldiet was invariably larger than those in the animals fed tannicacid-supplemented diet.

Effect of Dietery Tannic Acid on Lung Tumorigenesis. Theeffect of feeding tannic acid-supplemented diet on BP-inducedpulmonary neoplasia is shown in Table 3. Feeding of tannicacid-supplemented diet to mice prior to tumor initiation resulted in a significant decrease in the number (1.6 ±0.3 tumors/mouse in the tannic acid-supplemented diet group compared to3.1 ±0.5 tumors/mouse in the control diet group) as well as inthe incidence (30% decrease) of lung tumors. All the tumorswere identified histologically as adenomas and no evidence ofmalignancy was observed in any animal.

Effect of Feeding Tannic Acid in Diet on Skin Tumorigenesis.The effect of feeding tannic acid-supplemented diet on DMBA-initiated and 12-Otetradecanoylphorbol-13-acetate-promotedskin tumorigenesis is shown in Fig. 3. Tumor data are presentedas the percentage of mice with tumors (Fig. 3/4) and as thenumber of tumors per mouse (Fig. 3Ä) as a function of thenumber of weeks on test. Feeding of tannic acid-supplementeddiet to mice prior to tumor initiation resulted in an increase inthe latency period of tumor initiation. The latency period was3 weeks in the control group as compared to 6 weeks in thetannic acid-fed group of animals. However, at time periodsbeyond 6 weeks on test no significant difference was found intumor numbers or percentage of mice with tumors in the miceof the two groups. All skin tumors developed in both groups ofanimals were benign papillomas.

DISCUSSION

A great deal of attention has recently focused on the role ofdiet in cancer etiology with a view to develop strategies forcancer prevention (28). Several epidemiological studies havesuggested that diet influences human cancer risk (29). A largenumber of anticarcinogenic compounds have been identified infood. These are predominantly the plant products with highlydiversified chemical structures which comprise a part of virtually every human diet (28-30). Polyhydroxy plant phenolsare one important group of compounds in this category. Oneof the widely distributed members of this class is tannic acid,found in a variety of plants, some of which are also consumedin human diet (31). Tannic acid has been shown to havebeneficial pharmaceutical effects (32, 33). The feeding of tannicacid in diet in the present study resulted in protection againstBP-induced neoplasia of forestomach and lung while it showedonly a slight delay in the onset of skin tumorigenesis. It appearsthat administration of tannic acid p.o. has its strongest effectsin forestomach followed by lung. Previous reports from ourlaboratory and others have demonstrated that several plantphenols like quercetin (34), myricetin (14), ani hrati avie acid(10, 14), ellagic acid (35), and tannic acid (14) show inhibitoryeffects against PAH-induced tumorigenesis. Unlike the presentstudy, in most of the previous studies the application of theplant phenol was topical although their actual uptake is throughthe diet (31). Therefore, the results of the present study simulate, to some extent, the actual influence of these compoundsin diet.

The mechanisms by which these compounds exert their potential effects to inhibit chemical-induced tumorigenesis are notwell understood (1, 2). However, some of these compoundsinhibit certain P-450-dependent monooxygenase activitieswhile others induce phase II drug-metabolizing enzymes likeGST (9,10,12,18). Since carcinogenic PAHs require metabolicactivation by the P-450-dependent monooxygenase enzyme system to manifest their carcinogenic potential, the inhibition ofP-450 and associated monooxygenase activities might lead to

the inhibition of PAH metabolism and their subsequent bindingto DNA, thus inhibiting their carcinogenic response. Feedingof tannic acid in the diet in the present study was found toinhibit P-450-dependent AHH and ERD activities in forestomach and lung. This tumor-inhibitory response in the forestom

ach and lung reported in the present study may, therefore, bedue in part to the inhibition of P-450 monooxygenase activities.The reduction in [3H]BP binding to DNA in target organs in

the present study may also be due to the metabolic inhibitionof P-450-dependent metabolism of PAH in these tissues. It hasbeen suggested that the levels and persistence of specific carcin-ogen-DNA adducts, such as benzo(a)pyrene diol-epoxide I-deoxyguanosine adduct in the target tissue, correlate with thesusceptibility to BP-induced neoplasia (13, 26). In prior studieswe have shown that topical applications of tannic acid and other

Table 1 Effect of feeding 1% tannic acid-supplemented diet to Sencar mice on the binding of[3H]BP to epidermal, lung, and forestomach DNAFemale Sencar mice (6-8 weeks old) were fed AIN-76 (control) or 1% tannic acid-supplemented diet for 45 days. For epidermal DNA-binding studies [3H]BP was

applied topically, while for lung and forestomach DNA-binding studies (3H]BP was administered i.g. as described under "Materials and Methods." Each value

represents the mean ±SEM of at least three determinations.

EpidermisAddition

toAIN-76dietNone

1% tannic acidfmol

[3H]BP

bound/mgDNA351

±70310 ±20%

of inhibition12Lungfmol

[3H]BP

bound/mgDNA120

±2560 ±12°Forestomach%

of inhibition50fmol

[3H]BP

bound/mgDNA283

±22144 ±18°%

of inhibition47

' Statistically significant when compared to control diet (P < 0.001, Student's t test).

5786

Research. on August 14, 2021. © 1989 American Association for Cancercancerres.aacrjournals.org Downloaded from

TANNIC ACID PROTECTION AGAINST PAH TUMORIGENESIS

Table 2 Effect of feeding 1% tannic acid-supplemented diet to Sencar mice onBP-induced forestomach neoplasia

ForestomachtumorsAddition

toAIN-76diet"None

1% tannic acidNo.

of miceat risk3030%

of micewith tumors90

63No.

of tumors/mouse5.2

±0.73.3 ±0.6*

" Female Sencar mice (6-8 weeks old) were fed AIN-76 semipurified diet(control) or AIN-76 semipurified diet supplemented with 1% tannic acid for 45days after which they received BP (100 mg/kg body weight) in 0.2 ml of corn oilby intubation p.o. twice weekly for 4 weeks. At the end of the fourth week theanimals were switched to control diet on which they were maintained until thetermination of the experiment at 36 weeks. Data represent the mean ±SEM of30 animals.

* Statistically significant when compared to control diet (P< 0.001) (Student's

t test).

Table 3 Effect of feeding 1% tannic acid-supplemented diet to Sencar mice onBP-induced pulmonary adenoma formation

PulmonaryadenomasAddition

toAIN-76diet"None

1% tannic acidNo.

of miceat risk30

30%

of micewith tumors90

60No.

of tumors/mouse3.1

±0.51.6 + 0.3*

°Female Sencar mice (6-8 weeks old) were fed AIN-76 semipurified diet(control) or AIN-76 semipurified diet supplemented with 1% tannic acid for 45days after which they received single injection of BP ( 100 mg/kg body weight) in0.2 ml of corn oil and were then maintained on control diet until the terminationof the experiment at 36 weeks. Data represent the mean ±SEM of 30 animals.

* Statistically significant when compared to control diet (P< 0.001) (Student's

i test).

|80

^ 60

01 40.a

* 20

•¿�Control dietOTA diet

2 4 6 8 10 12 14 16

Weeks on Test

Fig. 3. Effect of feeding 1% tannic acid (TA)-supplemented diet to Sencarmice on DMBA-initiated and 12-O-tetradecanoylphorbol-13-acetate-promotedskin tumorigenesis. Female mice (6-8 weeks old) were fed AIN-76 (control) or1% tannic acid-supplemented AIN-76 diet for 45 days after which they receiveda single topical application of an initiating dose of DMBA (10 /ig/mice). Tendays later, the animals received twice weekly topical applications of 12-O-tetra-decanoylphorboI-13-acetate (3.24 nmol). On the first day of 12-O-tetradecanoyl-phorbol-13-acetate application, all animals were shifted to AIN-76 control diet.The percentage of mice with tumors (A) and the number of tumors per mouse(B) were plotted as a function of the number of weeks on test. None of theanimals in the DMBA alone, 12-O-tetradecanoylphorbol-13-acetate alone, oracetone alone groups developed neoplasms.

plant phenols to murine skin resulted in the reduction of PAH-DNA binding, particularly in the inhibition of benzo(a)pyrenediol-epoxide I-deoxyguanosine adduci formation (13). Thus,the inhibition in forestomach and pulmonary tumorigenesis bydietary tannic acid in the present study may be due to theinhibition of [3H]BP-DNA binding in forestomach and lung.

Similarly, induction of GST in forestomach and lung mightalso lead to increased conjugation leading to faster excretion of

the reactive intermediary metabolite(s). The induction of QRactivity may be helpful in reducing levels of toxic quinonederivatives of the carcinogen. Thus, the induction in the activities of both enzymes might contribute to the protection afforded by tannic acid against BP-induced neoplasia. However,other possible mechanisms such as the antioxidant action oftannic acid and its direct interaction with carcinogenic reactivemetabolite(s) cannot be ruled out.

In conclusion our data show that dietary supplementationwith low levels of tannic acid affords protection against PAH-induced forestomach and lung neoplasia in rodents. The mechanism^) of inhibition of tumorigenesis may be due to its inhibitory effect on microsomal monooxygenase activity, subsequentPAH-DNA binding, and its ability to induce detoxificationenzymes.

ACKNOWLEDGMENTS

Thanks are due to Daniel P. Bik and James D. Steele for technicalassistance and to Sandra Evans for preparing the manuscript.

REFERENCES

1. Committee on Diet, Nutrition and Cancer, Assembly of Life Sciences.National Research Council: Diet, Nutrition and Cancer. Washington, DC:United States Government Printing Office, 1982.

2. Ames, B. N. Dietary carcinogens and anticarcinogens. Science (Wash. DC),221: 1256-1264, 1983.

3. Workshop Conference on Nutrition in Cancer Causation and Prevention.Cancer Res., 43: 2385s-2519s, 1983.

4. Correa, P. Epidemiológica! correlations between diet and cancer frequency.Cancer Res., 41: 3685-3689, 1981.

5. Wattenberg, L. W. Inhibition of neoplasia by minor dietary constituents.Cancer Res., 43: 2448s-2453a, 1983.

6. Wattenberg, L. W. Chemoprevention of cancer. Cancer Res., 45: 1-8, 1985.7. Huang, M. T., Wood, A. W., Newmark, H. L., Sayer, S. M., Yagi, H., Jerina,

D. M., and Conney, A. H. Inhibition of the mutagenicity of bay-region diolepoxides of polycyclic aromatic hydrocarbons by phenolic plant flavonoids.Carcinogenesis (Lond.), 4: 1631-1637, 1983.

8. Huang, M. T., Chang, R. L., Wood, A. W., Newmark, H. L., Sayer, J. M.,Yagi, H., Jerina, D. M., and Conney, A. H. Inhibition of the mutagenicityof bay-region diol-epoxides of polycyclic aromatic hydrocarbons by tannicacid, hydroxylated anthraquinones and hydroxylated cinnamic acid derivatives. Carcinogenesis (Lond.), 6: 237-242, 1985.

9. Wattenberg, L. W., Coccia, J. B., and Lam, L. K. T. Inhibitory effects ofphenolic compounds on benzo(a)pyrene-induced neoplasia. Cancer Res., 40:2820-2823, 1980.

10. Mukhtar, H., Das, M., DelTito, B. J., and Bickers, D. R. Protection against3-methylcholanthrene induced skin tumorigenesis in BALB/c mice by ellagicacid. Biochem. Biophys. Res. Commun., 119: 751-757, 1984.

11. Wood, A. W., Haung, M. T., Chang, R. L., Newmark, H. L., Lehr, R. E.,Yagi, H., Sayer, J. M., Jerina, D. M., and Conney, A. H. Inhibition of themutagenicity of bay-region diol epoxides of polycyclic aromatic hydrocarbonsby naturally occurring plant phenols: exceptional activity of ellagic acid.Proc. Nati. Acad. Sci. USA, 79: 5513-5517, 1982.

12. Das, M., Mukhtar, H., Bik, D. P., and Bickers. D. R. Inhibition of epidermalxenobiotic metabolism in Sencar mice by naturally occurring plant phenols.Cancer Res., 4 7: 760-766, 1987.

13. Das, M., Khan, W. A., Asokan, P., Bickers, D. R., and Mukhtar, H. Inhibitionof polycyclic aromatic hydrocarbon-DNA adduci formation in epidermis andlungs of Sencar mice by naturally occurring plant phenols. Cancer Res., 47:767-773, 1987.

14. Mukhtar, H., Das, M., Khan, W. A., Wang, Z. Y., Bik, D. P., and Bickers,D. R. Exceptional activity of tannic acid among naturally occurring plantphenols in protecting against 7,12-dimethylbenz(a (anthracene-, benzo(a)-pyrene-, 3-methylcholanthrene-, and W-methyl-yv-nitrosourea-induced skintumorigenesis in mice. Cancer Res., 48: 2361-2365, 1988.

15. Nebert, D. W., and Gelboin, H. V. Substrate inducible microsomal arylhydrocarbon hydroxylase in mammalian cell culture. Assay and propertiesof induced enzyme. J. Biol. Chem., 234:6242-6249, 1968.

16. Pohl, R. J., and Fouts, J. R. A rapid method for assaying the metabolism of7-ethoxyresorufin by microsomal subcellular fractions. Anal. Biochem., 107:150-155, 1980.

17. Mukhtar, H., and Bend, J. R. Serum glutathione 5-transferases: perinataldevelopment, sex difference, and effect of carbon tetrachloride administrationon enzyme activity in the rat. Life Sci., 21: 1277-1286, 1977.

18. Benson, A. M., Hunkeler, M. J., and Talalay, P. Increase ofNAD(P)H:quinone reducíaseby dietary antioxidants: possible role in the

5787

Research. on August 14, 2021. © 1989 American Association for Cancercancerres.aacrjournals.org Downloaded from

TANNIC ACID PROTECTION AGAINST PAH TUMORIGENESIS

protection against carcinogenesis and toxicity. Proc. Nati. Acad. Sci. USA,77:5216-5220. 1980.

19. Khan. W. A., Das, M., Stick. S., Javed, S., Bickers, D. R., and Mukhtar, H.Induction of epidermal NAD(P)H:quinone reducíaseby chemical carcinogens: a possible mechanism for the detoxification. Biochem. Biophys. Res.Commun., 146: 126-133. 1987.

20. Lowry, O. H., Rosebrough. N. J., Farr. A. L.. and Randall. R. J. Proteinmeasurement with the Folin phenol reagent. J. Biol. Chem., 193: 265-275,1951.

21. loannou, Y. M., Wilson. A. G. E., and Anderson. M. W. Effect of butylatedhydroxyanisole, n-angelicalactone. and fi-naphthoflavone on benzofajpyrene:DNA adduci formation in viro in the forestomach. lung, and liver of mice.Cancer Res., 42: 1199-1204, 1982.

22. Kates, J., and Beeson. J. Ribonucleic acid synthesis and release of RNA invaccinia cores. J. Mol. Biol., 50: 1-10, 1970.

23. Diamond. L., Defendi, V., and Brookes. P. The initiation of 7,12-dimethyl-benz(a)anthracene with cells sensitive and resistant to toxicity induced bythis carcinogen. Cancer Res., 27: 891-897, 1967.

24. Wattenberg, L. W. Inhibitory effects of benzyl isothiocyanate administeredshortly before diethylnittrosamine or benzo(a)pyrene on pulmonary andforestomach neoplasia in A/J mice. Carcinogenesis (l und.). 8: 1971-1973,1987.

25. Shimkin, M. B. Pulmonary tumors in experimental animals. Adv. CancerRes., J: 223-267, 1955.

26. Conney. A. H. Induction of microsomal enzymes by foreign chemicals and

carcinogenesis by polycyclic aromatic hydrocarbons. G. H. A. Clowes Memorial Lecture. Cancer Res., 42: 4875-4917, 1982.

27. Benson, A. M., Batzinger, R. P., Ou, S. J. L., Bueling, E., Cha, Y-N., andTalalay, P. Elevation of hepatic glutathione 5-transferase activities andprotection against mutagenic metabolites by dietary antioxidants. CancerRes., J«:4486-4495, 1978.

28. Olsen, S. J., and Love, R. R. A new direction in preventive oncology:chemoprevention. Semin. Oncol. Nursing, 2: 211-221, 1986.

29. Cohen, L. A. Diet and cancer. Sei. Am., 257: 42-48, 1987.30. Ramel, C, Alekperov, U. K., Ames, B. N., Kada, T., and Wattenberg, L. W.

Inhibitors of mutagenesis and their relevance to carcinogenesis. Mutât.Res.,168: 47-65, 1986.

31. Haslam. E. Vegetable tannins. Recent Adv. Phytochem., 72:475-523, 1979.32. Konishi, E., and Hotta, S. Effects of fannie acid and its related compounds

upon chikungunya virus. Microbiol. Inumino!.. 2.?:609-667, 1979.33. Okonogi, T., Hattoriz, Z., Ogiso, A., and Mitsui, S. Detoxification by

persimmon tannin of snake venoms and bacterial toxins. Toxicon, 17: 524-527, 1979.

34. Verma, A. K., Johnson. J. A., Yould, M. N., and Tanner, M. A. Inhibitionof 7,12-dimethylbenz(o(anthracene- and iV-nitrosomethylura-induced ratmammary cancer by dietary flavonol quercetin. Cancer Res., 48:5754-5758.1988.

35. Mukhtar, H., Das, M., and Bickers, D. R. Inhibition of 3-methylcholan-threne-induced skin tumorigenicity in BALB/c mice by chronic oral feedingof trace amounts of ellagic acid in drinking water. Cancer Res., 46: 2262-2265, 1986.

5788

Research. on August 14, 2021. © 1989 American Association for Cancercancerres.aacrjournals.org Downloaded from

1989;49:5784-5788. Cancer Res   Mohammad Athar, Wasiuddin A. Khan and Hasan Mukhtar  Tumorigenicity in Sencar Mice

andForestomach Polycyclic Aromatic Hydrocarbon Metabolism Effect of Dietary Tannic Acid on Epidermal, Lung, and

  Updated version

  http://cancerres.aacrjournals.org/content/49/21/5784

Access the most recent version of this article at:

   

   

   

  E-mail alerts related to this article or journal.Sign up to receive free email-alerts

  Subscriptions

Reprints and

  .pubs@aacr.orgDepartment at

To order reprints of this article or to subscribe to the journal, contact the AACR Publications

  Permissions

  Rightslink site. Click on "Request Permissions" which will take you to the Copyright Clearance Center's (CCC)

.http://cancerres.aacrjournals.org/content/49/21/5784To request permission to re-use all or part of this article, use this link

Research. on August 14, 2021. © 1989 American Association for Cancercancerres.aacrjournals.org Downloaded from