J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0

. sc iencedi rec t .com

ava i lab le at www

journal homepage: www.elsevier .com/ locate / j f f

Anti-obesity effects of epigallocatechin-3-gallate, orange peelextract, black tea extract, caffeine and their combinationsin a mouse model

Yu-Wen Huanga, Yue Liua, Slavik Dushenkovb, Chi-Tang Hoc, Mou-Tuan Huanga,*

aDepartment of Chemical Biology, Susan Lehman Cullman Laboratory for Cancer Research, School of Pharmacy,

Rutgers University, Piscataway, NJ 08854-8020, USAbBiotech, Rutgers University, New Brunswick, NJ 08901, USAcDepartment of Food Science, Rutgers University, New Brunswick, NJ 08901, USA

A R T I C L E I N F O

Article history:

Received 12 December 2008

Received in revised form

15 April 2009

Accepted 16 June 2009

Available online 23 July 2009

Keywords:

Anti-obesity, Caffeine

Orange peel extract

Epigallocatechin gallate

Black tea extract

1756-4646/$ - see front matter � 2009 Elsevidoi:10.1016/j.jff.2009.06.002

* Corresponding author: Tel.: +1 732 445 3400E-mail address: mthuang@rci.rutgers.edu

A B S T R A C T

The anti-obesity effects of epigallocatechin-3-gallate (EGCG), orange peel extract (OPE),

black tea extract (BTE), and caffeine (CF) in female CF-1 mice were studied. Female CF-1

mice were fed high-fat diets containing 0.1% EGCG, 0.2% OPE, 0.2% BTE and 0.05% caffeine

alone and in combination for 10 weeks. The body weight gain and weights of abdominal fat

and brown adipose tissue were significantly reduced in mice whose diets contained OPE,

BTE, caffeine, OPE + BTE and OPE + CF. Notably, mice fed a high-fat diet supplemented daily

with 0.2% OPE + 0.2% BTE + 0.05% CF prevented body weight gain by 48.8%, parametrial fat

pad weight by 88.2%, retroperitoneal fat pad weight by 82.8% and brown adipose tissue by

63.7% compared with mice fed a high-fat diet. On the basis of these findings, it was con-

cluded that oral feeding of orange peel extract, black tea extract and caffeine had anti-obes-

ity effects by suppressing body weight gain and adipose tissue formation.

� 2009 Elsevier Ltd. All rights reserved.

1. Introduction

Obesity, a condition in which an abnormally large amount of

fat is stored in the adipose tissue, resulting in an increase in

body weight, is one of the major public health problems in

the United States and other developed countries. Obesity is

generally associated with an increased risk of excessive fat-

related metabolic diseases (EFRMD) and chronic diseases,

including type 2 diabetes mellitus, hypertension and dyslipi-

demia (Bays et al., 2006; Mazzucotelli & Lanqin, 2006; Reeves

et al., 2006). In addition, excess weight is generally linked to

the onset of several major chronic diseases such as cardiovas-

cular diseases, and cancers. There is also strong evidence that

obesity is associated with increased morbidity and mortality.

er Ltd. All rights reserved

x252; fax: +1 732 445 068(M.-T. Huang).

For thousands of years, tea has been the most widely con-

sumed beverage in Asian countries. Today, the health benefits

of tea have gained more recognition from consumers and sci-

entists. Tea has been investigated for its ability to prevent sev-

eral chronic diseases, including cancer, neurodegenerative

diseases and obesity (Higdon & Frei, 2003). Reduction of serum

cholesterol level, prevention of arteriosclerosis and protection

of blood vessels have been reported as integrated pharmaco-

logical effects of tea (Yang & Koo, 1997; Yang et al., 2001). EGCG

(epigallocatechin-3-gallate) is one of the major catechins in

green tea. It possesses strong anti-oxidant properties, which

are believed to contribute to the possible health benefits of

tea consumption. EGCG is also considered to serve as a

chemopreventive agent for cancer, as well as for obesity and

.

7.

J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0 305

cardiovascular diseases (Yang & Wang, 1993; Yang, 1999;

Murase et al., 2002; Zheng et al., 2004). Evidence shows that

green tea and its catechins, especially EGCG, reduce body

weight as well as adipose tissue and blood lipid levels

(Muramatsu et al., 1986; Vinson & Dabbagh, 1998; Kao et al.,

2000a; Wolfram et al., 2005; Klaus et al., 2005). Black tea repre-

sents approximately 78% of the total tea consumed in the

world, whereas green tea accounts for approximately 20% of

the tea consumed (Siddique et al., 2004). Green tea catechins

have been extensively investigated for their health benefits

for decades, while black tea extracts have not been studied un-

til recently. Even though green tea reduces the risk of several

chronic diseases, the effect of black tea is more controversial

(Cheng, 2006).

Polymethoxyflavones (PMFs), the major components of or-

ange peel, have been found to have health benefits, including

anti-inflammatory, anti-carcinogenic, anti-viral, anti-

oxidant, anti-thrombogenic and anti-atherogenic properties

(Middleton et al., 2000; Whitman et al., 2005; Lai et al., 2007;

Li et al., 2009).

Caffeine has been reported to suppress body weight gain

by stimulating thermogenesis, extending sympathetic stimu-

lation, suppressing food intake and reducing adipose tissue

mass (Tremblay et al., 1988; Dulloo, 1993; Racotta et al.,

1994; Dulloo et al., 1999, 2000; Kazuo et al., 2005). The present

study was designed to investigate the anti-obesity effects of

green tea EGCG, black tea extract, orange peel extract and caf-

feine individually and in combination in mice.

2. Materials and methods

2.1. Materials

EGCG (97% pure with �3% ECG) was provided by Mitsui Norin

Co. Ltd. (Shizuoka, Japan). Orange peel extract (OPE, from

cold-pressed sweet orange peel oil) was obtained from Florida

Flavors Company (Lakeland, Florida, USA). OPE contained

5.21% 3,5,6,7,8,3 0,4 0-heptamethoxyflavone, 8.80% tangeretin,

14.82% nobiletin and 2.70% sinesetin. Black tea extract was

obtained from WellGen, Inc. (New Brunswick, NJ, USA) and

contained 6.90% theaflavin (TF), 14.41% theaflavin-3-gallate

(TF2a), 4.58% theaflavin-3 0-gallate (TF-2b), 12.56% theaflavin-

3,3 0-digallate (TF-3), 1.14% (-)-epicatechin (EC), 15.00% (-)-epi-

gallocatechin gallate (EGCG) and 11.20% (-)-epicatechin gallate

(EGC). Caffeine (99% pure) was purchased from Sigma Chem-

ical Co. (St. Louis, MO, USA).

2.2. Animals and diets

Female CF-1 mice, 6 weeks old, were purchased from Charles

River Breeding Laboratories (Kingston, NY, USA). The mice

were randomly divided into 10 groups (10 mice per group) ex-

cept the caffeine group which had 9 mice. Mice were housed

in plastic cages, in an air-conditioned room with the temper-

ature at 22–24 �C under a 12 h light-dark cycle (the light period

was from 06:00 to 18:00) and humidity of 50 ± 10%. Mice in dif-

ferent groups were fed with different diets for 10 weeks. The

low-fat AIN-76A diet contained 5% corn oil (w/w), 66% carbo-

hydrate, 20% casein, 5% cellulose, 1% vitamins, and 3.5% min-

erals; the high-fat AIN-76A diet contained 20.7% corn oil,

44.9% carbohydrate, 20% casein, 5% cellulose, 1% vitamins,

and 3.5% minerals. EGCG, black tea extract, orange peel ex-

tract and caffeine were added to the high-fat diet at concen-

trations of 0.1, 0.2, 0.2, and 0.05% (w/w), respectively, alone

and in combination.

2.3. Body weight, food and water intake

The body weight of each mouse was monitored weekly. Food

and water intake were measured on a per cage (10 mice per

cage) basis 3 times per week and the averages of food and

water consumed were calculated weekly. Unit for food con-

sumption was gram/day/mouse (g/d/m) and unit for water

consumption was ml/day/mouse (ml/d/m).

2.4. Determination of adipose tissue mass

The weights of parametrial fat pad, retroperitoneal fat pad

and brown adipose tissue were measured to 0.1 g using an

analytical balance.

2.5. Statistical analysis of the data

The values obtained were expressed as the mean ± SE (stan-

dard error). Statistical comparisons of two groups were deter-

mined by the Student’s t-test. Statistical significance was

defined as p < 0.05.

3. Results

3.1. Body weight

The effects of dietary (-)-epigallocatechin-3-gallate (EGCG), or-

ange peel extract (OPE), black tea extract (BTE) and caffeine

(CE) on body weight change are shown in Fig. 1. The body

weight gain was significantly reduced by 0.2% OPE (32%),

0.2% BTE (35.7%) and 0.05% CF (41.1%) diets from the initial

week until the end of feeding, but not by the 0.1% EGCG diet

compared with mice fed on a high-fat diet.

Fig. 2 shows the body weights of mice administered differ-

ent combinations of 0.2% OPE + 0.2% BTE, 0.2% OPE + 0.1%

EGCG, 0.2% OPE + 0.05% CF and 0.2% OPE + 0.2% BTE + 0.05%

CF. These results indicated that mice body weights decreased

by 43.4, 23.3 and 48.4%, respectively, when they were fed with

high-fat diets containing 0.2% OPE + 0.2% BTE, 0.2%

OPE + 0.05% CF or 0.2% OPE + 0.2% BTE + 0.05% CF diets. Diet

containing 0.2% OPE + 0.1% EGCG did not inhibit the body

weight gain.

3.2. Energy intake

Since OPE, BTE and CF had a significant suppressive effect on

body weight, the energy intake was compared between the

groups given tested materials individually or in combination.

The effect of different compounds on food intake of mice fed

the high-fat and low-fat diets was not different among all

groups (data not shown), including 0.1% EGCG;0.2% orange peel

extracts (OPE); 0.2% black tea extracts (BTE); 0.05% caffeine (CF);

0.2% OPE + 0.1% EGCG; 0.2% OPE + 0.2% BTE; 0.2% OPE +

0.05% CF; 0.2% OPE + 0.2% BTE + 0.05% CF in a high-fat diet.

Fig. 1 – Female CF-1 mice (6 weeks old; 10 mice per group) were given a high-fat diet (AIN-76A 20% corn oil); 0.2% OPE, 0.2%

BTE, or 0.05% CF in high-fat diet and water ad libitum for 10 weeks. Body weights were monitored weekly for 10 weeks. Data

are mean ± SE (n = 10). *significant differences (p < 0.05).

306 J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0

3.3. Adipose tissue formation and accumulation

To elucidate the anti-obesity effect of OPE, BTE, EGCG and CF,

we weighed the parametrial fat pad, retroperitoneal fat pad

and brown adipose tissue after feeding a 0.2% OPE, 0.2%

BTE, 0.01% EGCG or 0.05% CF diet for 10 weeks. Supplementa-

tion with OPE, BTE and CF significantly suppressed fat accu-

mulation, in comparison with mice fed a high-fat diet.

Furthermore, the combination of two different compounds

gave a better result in suppression of the parametrial fat

pad, the retroperitoneal fat pad as well as brown adipose tis-

sue weights. Notably, we also found that supplementation of

a high-fat diet with the combination of 0.2% OPE, 0.2% BTE

and 0.05% CF was the most effective treatment which de-

creased the parametrial and retroperitoneal fat pad weight

by 88.2% and 82.8%, respectively, and brown adipose tissue

by 63.7% compared with mice fed a high-fat diet (Figs. 3–5).

4. Discussion

In the present study we demonstrated that feeding 0.2% of

OPE, 0.2% of BTE and 0.05% of CF individually or a combina-

tion of 0.2% OPE + 0.2% BTE; 0.2% OPE + 0.05% CF; 0.2%

BTE + 0.05% CF and 0.2% OPE + 0.2% BTE + 0.05% CF in the

Fig. 2 – Female CF-1 mice (6 weeks old; 10 mice per group) were given high-fat diet; 0.2% OPE + 0.2% BTE, 0.2% OPE + 0.1%

EGCG, 0.2% OPE + 0.05% CF or 0.2% OPE + 0.2% BTE + 0.05% CF in high-fat diet and water ad libitum for 10 weeks. Body weights

were monitored weekly for 10 weeks. Data are mean ± SE (n = 10). *significant differences (p < 0.05).

J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0 307

high-fat diet inhibited body weight gain and decreased the

accumulation of fat adipose in the body in comparison with

the mice fed a high-fat diet. The food and water consump-

tions were not significantly different between the specific die-

tary group and the control high-fat group. These modulated

diets, with added EGCG, OPE, BTE and caffeine, did not influ-

ence the mice’s appetite and as energy intake for a 10-week

period. Although no significant difference was apparent in

the food intake between the high-fat diet (20% corn oil in

AIN-76A diet) group and the low-fat diet (5% corn oil in AIN-

76A diet) groups, there were significant increases in the levels

of body weight gain, parametrial fat pad weight, retroperito-

neal fat pad weight and brown adipose tissue in mice fed

the high-fat diet compared with mice fed the low-fat diet

for 10 weeks. The results clearly demonstrated that body

weight gain and fat accumulation in mice were remarkably

increased by feeding on the high-fat diet. This diet-induced

obesity model was used in this study to elucidate the effects

of natural products and their combinations on body weight

gain and fat accumulation in mice.

It has been reported that catechins, especially EGCG, have

anti-obesity effects in mice by lowering food intake and pre-

venting body weight gain (Kao et al., 2000b; Murase et al.,

2002). Moreover, previous research also shows that EGCG re-

duced body fat accumulation in humans (Nagao et al., 2001).

Although the diet containing 0.1% EGCG in our study did

not influence the body weight and food intake in mice, it sig-

nificantly inhibited the P-fat pad, R-fat pad and brown adi-

pose tissue accumulation compared with mice fed a high-

fat diet (Figs. 3–5). The dose-dependent effect on the anti-

obesity action of EGCG has been suggested (Zheng et al.,

2004). We can conclude that 0.1% EGCG might have anti-obes-

ity effects by preventing white adipose tissue and brown adi-

pose tissue accumulation. However, a dose higher than 0.1%

Fig. 3 – Female CF-1 mice (6 weeks old; 10 mice per group) were fed with high-fat diet (AIN-76A 20% corn oil) and various plant

extracts in high-fat diet for 10 weeks. The mice were sacrificed and abdominal fats (parametrial fats) were removed and

weighed. Data are average weight of parametrial fat (P-fat) for 10 mice (mean ± SE). *significant difference (p < 0.05).

Fig. 4 – Female CF-1 mice (6 weeks old; 10 mice per group) were fed with high-fat diet (AIN-76A 20% corn oil) and various plant

extracts in high-fat diet for 10 weeks. The mice were sacrificed and retroperitoneal fat (R-fat) were removed and weighed.

Data are average weight of retroperitoneal fat for 10 mice (mean ± SE). *significant difference (p < 0.05).

308 J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0

might be needed to observe the anti-obesity effect of EGCG on

body weight reduction.

In this work, mice fed a high-fat diet supplemented daily

with 0.2% OPE, 0.2% BTE and 0.05% CF prevented body weight

gain, P-fat pad weight, R-fat pad weight and brown adipose

tissue in comparison with mice fed a high-fat diet (Figs. 3–

5). These results indicate that orange peel extract, black tea

extract and caffeine had distinct anti-obesity effects and led

to body weight reduction and white adipose tissue and brown

adipose tissue accumulation suppression. Interestingly, in the

molar equivalent BTE, which is approximately 0.1 mol for

0.2%, demonstrated the higher anti obesity-activity compared

to other individual compounds, such as 0.1% EGCG (0.2 mol),

0.2% OPE (0.2 mol) and 0.05% CF (0.2 mol). Using a mole base,

the order of anti-obesity is BTE (0.1 mol) > CF (0.2 mol) > OPE

(0.2 mol) > EGCG (0.2 mol).

As the data show, 0.2% orange peel extracts and 0.1% EGCG

significantly reduced body weight gain by 32%. To our sur-

prise, the combinations of 0.2% OPE and 0.1% EGCG did not re-

duce the body weight in mice (Fig. 2). Similar results also

show that the parametrial fat pad weight and retroperitoneal

fat pad weight were increased in mice that were fed with a

combination 0.2% OPE + 0.1% EGCG diet (Figs. 3 and 4). This

may indicate that OPE and EGCG, when present together in

a diet, may interfere and suppress the anti-obesity potential

of individual chemicals.

Fig. 5 – Female CF-1 mice (6 weeks old; 10 mice per group) were fed with high-fat diet (AIN-76A 20% corn oil) and various plant

extracts in high-fat diet for 10 weeks. The mice were sacrificed and brown adipose tissue (BAT) was removed and weighed.

Data are average weight of brown adipose tissue for 10 mice (mean ± SE). *significant difference (p < 0.05).

J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0 309

The combination of orange peel extract and black tea ex-

tract provided better anti-obesity effects than orange peel ex-

tract or black tea extract alone. Caffeine also acted

concurrently with orange peel extract to generate anti-obesity

activities in mice. A high-fat diet supplemented daily with a

combination of 0.2% OPE, 0.2% BTE and 0.05% CF remarkably

decreased the parametrial fat pad weight, retroperitoneal fat

pad weight and brown adipose tissue compared with mice

fed a high-fat diet (Figs. 3–5). These results indicate that the

combination of orange peel extract, black tea extract and caf-

feine have the best anti-obesity effects by reducing body

weight gain and by preventing formation and accumulation

of P-fat pad weight, R-fat pad weight and brown adipose tis-

sue mass. Although mice were temporarily insensitive to

the effect of 0.2% OPE + 0.05% CF, the addition of 0.2% BTE

to the diet apparently eliminated this predicament. On the

other hand, we demonstrated that not just orange peel ex-

tract acted together with black tea extract in manifesting bet-

ter anti-obesity activities, but also caffeine cooperated with

these two compounds to achieve the most effective anti-obes-

ity action.

We also examined liver weight and spleen weight in order

to determine if these modulated diets have undesirable side

effects on the body. In general, enlargement of the liver or

spleen might be an indicator for pathologic development in

the body. No significant difference was observed among all

groups considered (data not shown). The spleen weight was

also under normal conditions for all groups (data not shown).

The mechanisms of anti-obesity actions of OPE, BTE, caf-

feine and their combinations are not yet known. However,

black tea extract and theaflavins from black tea extract have

been reported to act as more potent inhibitors of lipid syn-

thase and lipase activity than that of green tea extract and

EGCG (Lin and Lin-Shiau, 2009). Inhibition of intestinal lipase

activity appears to limit lipid absorption, since triacylglyce-

rols must be hydrolyzed to monoacylglycerols before being

absorbed. Caffeine may enhance animal activity and move-

ment. The combination of two different mechanisms of ac-

tion by black tea extract and caffeine may increase the

activity.

In summary, we demonstrated that long-term feeding of

orange peel extract, black tea extract and caffeine is beneficial

for the suppression of high-fat diet-induced obesity, and that

their effects may be attributed to the inhibition of adipose tis-

sue formation and reduction of adipose tissue mass. More-

over, better results can be achieved by combination of

different compounds. In this study, orange peel extract acted

synergistically with black tea extract and caffeine to render

the most effective anti-obesity action. The results suggest

that a sufficient supply of OPE, BTE and CF may prevent obes-

ity and possibly reduce the risk of associated diseases, such

as coronary heart disease.

R E F E R E N C E S

Bays, H., Blonde, L., & Rosenson, R. (2006). Adiposopathy: how dodiet, exercise and weight loss drug therapies improvemetabolic disease in overweight patients? Expert Review ofCardiovascular Therapy, 4, 871–895.

Cheng, T. O. (2006). All teas are not created equal, the Chinesegreen tea and cardiovascular health. International Journal ofCardiology, 108, 301–308.

Dulloo, A. G. (1993). Ephedrine, xanthines and prostaglandin-inhibitors: actions and interactions in the stimulation ofthermogenesis. International Journal of Obesity and RelatedMetabolic Disorders, 17(Suppl 1), S35–S40.

Dulloo, A. G., Duret, C., Rohrer, D., Girardier, L., Mensi, N., Fathi,M., Chantre, P., & Vandermander, J. (1999). Efficacy of a greentea extract rich in catechin polyphenols and caffeine inincreasing 24-hour energy expenditure and fat oxidation inhumans. American Journal of Clinical Nutrition, 70, 1040–1045.

Dulloo, A. G., Seydoux, J., Girardier, L., Chantre, P., &Vandermander, J. (2000). Green tea and thermogenesis:interactions between catechin-polyphenols, caffeine and

310 J O U R N A L O F F U N C T I O N A L F O O D S 1 ( 2 0 0 9 ) 3 0 4 – 3 1 0

sympathetic activity. International Journal of Obesity and RelatedMetabolic Disorders, 24, 252–258.

Higdon, V., & Frei, B. (2003). Tea catechins and polyphenols: healtheffects, metabolism, and antioxidant functions. CriticalReviews in Food Science and Nutrition, 43, 89–143.

Kao, Y. H., Hiipakka, R. A., & Liao, S. (2000a). Modulating ofendocrine systems and food intake by green teaepigallocatechin gallate. Endocrinology, 141, 980–987.

Kao, Y. H., Hiipakka, R. A., & Liao, S. (2000b). Modulation of obesityby a green tea catechin. American Journal of Clinical Nutrition, 72,1232–1241.

Kazuo, K. H., Akie, M., Yoshinobu, M., & Toshichika, T. (2005).Effects of caffeine on the body fat and lipid metabolism of ratsfed on a high-fat diet. Bioscience, Biotechnology, and Biochimistry,69, 2219–2223.

Klaus, S., Pultz, S., Thone-Reineke, C., & Wolfram, S. (2005).Epigallocatechin gallate attenuates diet-induced obesity inmice by decreasing ebergy obsorption and increasing fatoxidation. International Journal of Obesity and Related MetabolicDisorders, 29, 615–623.

Lai, C. S., Li, S., Chai, C. Y., Lo, C. Y., Ho, C.-T., Wang, Y. J., & Pan,M. H. (2007). Inhibitory effect of citrus 5-hydroxy-3, 6, 7, 8, 3 0,40-hexamethoxyflavone on 12-O-tetradecanoylphorbol 13-acetate-induced skin inflammation and tumor promotion inmice. Carcinogenesis, 28, 2581–2588.

Li, S., Pan, M. H., Lo, C. Y., Tan, D., Wang, Y., Shahidi, F., & Ho, C.-T.(2009). Chemistry and health effects of polymethoxyflavonesand hydroxylated polymethoxyflavones. Journal of FunctionalFoods, 1, 2–12.

Lin, J. K., & Lin-Shiau, S. Y. (2009). Fermented tea is more effectivethan unfermented tea in suppressing lipogenesis and obesity.In C. T. Ho, J. K. Lin, & F. Shahidi (Eds.), Tea and Tea Products:Chemistry and Health Promoting Properties. Boca Raton, FL: CRCPress.

Mazzucotelli, A., & Lanqin, D. (2006). Fatty acid mobilization andtheir use in adipose tissue. Journal de la Societe de Biologie, 200,83–91.

Middleton, E., Jr., Kandaswami, C., & Theoharides, T. C. (2000). Theeffects of plant flavonoids on mammalian cells: implicationsfor inflammation, heart disease, and cancer. PharmacologicalReviews, 52, 673–751.

Muramatsu, K., Fuduyo, M., & Hara, Y. (1986). Effect of greentea catechins on plasma cholesterol level in cholesterol-fedrats. Journal of Nutritional Science and Vitaminology, 32,613–622.

Murase, T., Nagasawa, A., Suzuki, J., Hase, T., & Tokimitsu, I.(2002). Beneficial effects of tea catechins on diet-inducedobesity: stimulation of lipid catabolism in the liver.

International Journal of Obesity and Related Metabolic Disorders, 26,1459–1464.

Nagao, T., Meguro, S., Soga, S., Otsuka, A., Tomonobu, K., Fumoto,S., Chikama, A., Mori, K., Yuzawa, M., Watanabe, H., Hase, T.,Tanaka, Y., Tokimitsu, I., Shimasaki, H., & Itakura, H. (2001).Tea catechins suppress accumulation of body fat in humans.Journal of Oleo Science, 50, 717–728.

Racotta, I. S., Leblanc, J., & Richard, D. (1994). The effect of caffeineon food intake in rats: involvement of corticotropin-releasingfactor and the sympatho-adrenal system. PharmacologyBiochemistry and Behavior, 48, 887–892.

Reeves, A. F., Rees, J. M., Schiff, M., & Hujoel, P. (2006). Total bodyweight and waist circumference associated with chronicperiodontitis among adolescents in the United States. Archivesof Pediatrics & Adolescent Medicine, 160, 894–899.

Siddique, I. A., Afaq, F., Adhami, V. M., Ahmad, N., & Mukhtar, H.(2004). Antioxidants of the beverage tea in promotion ofhuman health. Antioxidants and Redox Signaling, 6, 571–582.

Tremblay, A., Masson, E., Leduc, S., Houde, A., & Despres, J. P.(1988). Caffeine reduces spontaneous energy intake in menbut not in women. Nutrition Research, 8, 553–558.

Vinson, J. A., & Dabbagh, Y. A. (1998). Effect of green and black teasupplementation on lipids, lipid oxidation and fibrinogen inhamsters: mechanisms for the epidemiological benefits of teadrinking. FEBS Letters, 433, 44–46.

Whitman, S. C., Kurowska, E. M., Manthey, J. A., & Daugherty, A.(2005). Nobiletin, a citrus flavonoid isolated from tangerines,selectively inhibits class a scavenger receptor-mediatedmetabolism of acetylated LDL by mouse macrophages.Atherosclerosis, 178, 25–32.

Wolfram, S., Raederstorff, D., Wang, Y., Teixeira, S. R., Elste, V., &Weber, P. (2005). TEAVIGO (epigallocatechin gallate)supplementation prevents obesity in rodents by reducingadipose tissue mass. Annals of Nutrition and Metabolism, 49,54–63.

Yang, C. S., & Wang, Z. Y. (1993). J. Effect of tea polyphenols andEGCG on nasopharyngeal carcinoma cell proliferation and themechanisms involved. Journal of National Cancer Institute, 85,1038–1049.

Yang, C. S. (1999). Tea and health. Nutrition, 1999(15), 946–949.Yang, M., Wang, C., & Chen, H. (2001). Green, oolong and black tea

extracts modulate lipid metabolism in hyperlipidemia rats fedhigh-sucrose diet. Journal of Nutritional Biochemistry, 12, 14–20.

Yang, T. T. C., & Koo, M. W. L. (1997). Hypocholesterolemic effectsof Chinese tea. Pharmocological Research, 35, 505–512.

Zheng, G., Sayama, K., Okubo, T., Juneja, L. R., & Oguni, I. (2004).Anti-obesity effects of three major components of green tea,catechins, caffeine and theanine, in mice. In Vivo, 18, 55–62.