**Abbreviations**

AD=Alzheimer's disease ALT=alanine aminotransferase AML=acute myelocytic leukemia

APP=amyloid precursor protein

ATRA=all-*trans* retinoic acid

BBB=blood brain barrier

BKO=β-globin gene knockout

BP=benz[a]-pyrene

C=catechin

counteract against tumorigenesis and DNA damage [106]. Mu and colleagues have identified an association between tea consumption and decreased cancer risk [107]. Surprisingly, EGCG in green tea exerted inhibitory effects on skin cancer, hepatocellular carcinoma and duodenal cancer, on metastasis of the melanoma cell line in lung cancer in mice, possibly by blocking the interaction of their tumor promoters with their own membrane receptors called sealing effects. Green tea significantly prevented growth of Namalwa, RAP1-EIO and HS-Sultan tumors transplanted intraperitoneally in the NOD/SCID mice; possibly by impairment of tumor invasion, anti-angiogenesis and by cell apoptosis induction [108]. EGCG decreased ornithine decarboxylase (ODC) and Ras and Jun oncogene levels, and also inhibited tyrosine kinase (TK) as well as mitogen-activated protein kinase (MAPK) activities in the transformed

Green tea has long been considered a refreshing beverage that is prepared from tea (*Camellia sinensis*) shoots. It exerts many beneficial health effects, including anti-oxidant, anti-diabetic, hypolipidemic, anti-aging, anti-gout, neuroprotective, cardioprotective, hepatoprotective, anti-inflammatory, anti-carcinogenesis properties, among others. Variations of strain, source, geographic area, altitude, climate, cultivation, duration of fermentation and the preparation process can give rise to differences in the amounts of catechins derivatives, nutritional values, biological activities and the pharmacological properties of green tea products. EGCG is the most abundant type of catechin found in green tea and also the most relevant phytochemical displaying an influencing in several diseases and disorders. Some green tea catechins are not absorbed, while some catechins are absorbed from the intestine into the blood, and then are biologically transformed in liver microsomes by glucuronidation, sulfation and methylation reactions and ultimately excreted through the bile and urine. In this article, we have focused on the efficacy of green tea crude extract and catechins fractions, particularly EGCG in 1) depleting free radicals in normal cells, 2) removing chelatable iron from vital organs with iron overload, 3) lowering the levels of the risk factors of cardiovascular diseases, 4) inhibiting growth and proliferation of leukemic cells and solid malignant tumors, and 5) scavenging ROS and a repletion in the reducing power in neuronal tissues. The recognized benefits of green tea are that it is 1) potent in antioxidation, 2) effective in iron chelation, 3) beneficial in the inhibition of fat digestion, absorption and synthesis, 4) apoptotic induction, and 5) neuropro‐ tection, respectively. Green tea has played a prominent role in the lives of many over time as a beverage, as a component of the diet, and now a substance that can be applied in drugs. The

NIH-pATMras fibroblasts [109].

378 Pharmacology and Nutritional Intervention in the Treatment of Disease

benefits of which have now been evidently documented.

**7. Conclusions**

**Abbreviations**

AD=Alzheimer's disease

ALT=alanine aminotransferase

CLL=chronic lymphocytic leukemia

COMT=catechol-*O*-methyltransferase

CVD=cardiovascular diseases

DAPK2=death-associated protein kinase 2

DFP=deferiprone

DH=double heterozygous β-globin gene knockout carrying human β<sup>E</sup> gene

DMBA=7,12-dimethylbenz[a]-anthracene

DMT1=divalent metal ion transporter-1

DW=deionized water

EC=epicatechin

ECG=epicatechin 3-gallate

EGC=epigallocatechin

EGCG=epigallocatechin 3-gallate

FAS=fatty acid synthase

GA=gallic acid

GC=gallocatechin

G-CSF=granulocyte colony stimulating factor

GM-CSF=granulocyte macrophage colony stimulating factor

GSH=reduced glutathione

GSSG=oxidized glutathione

GTE=green tea extract

Hb=hemoglobin

HDL=high-density lipoprotein

SULT=sulfotransferases

TK=tyrosine kinase

Treg=regulatory T cells

Vd=distribution volume

XO=xanthine oxidase

**Acknowledgements**

**Author details**

Thailand

Thailand

Sakaewan Ounjaijean<sup>1</sup>

WT=wild-type

T1/2β=beta-elimination half-lives

TEAC=trolox-equivalent antioxidant capacity

TPA=12-*O*-tetradecanoylphorbol-13-acetate

VEGF=vascular endothelial growth factor

through Professor Suthat Fucharoen, MD.

, Suthat Fucharoen<sup>2</sup>

\*Address all correspondence to: ssrichai@med.cmu.ac.th

UGT=uridine diphosphate-glucuronosyltransferase

This work was partially supported by the Office of Higher Education Commission and Mahidol University under the National Research University Initiative, Thailand Research Fund through Professor Suthat Fucharoen, MD. and by a Research Chair Grant from the National Science and Technology Development Agency (NSTDA) and Mahidol University

1 Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand

2 Thalassemia Research Center, Institute of Bioscience, Mahidol University, NakornPathom,

3 Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai,

and Somdet Srichairatanakool3\*

Green Tea: Just a Drink or Nutraceutical http://dx.doi.org/10.5772/57519 381

HGF=hematopoietic growth factors HMG-Co A=3-hydroxy-3-methylglutaryl-coenzyme A hTERT=human telomerase reverse transcriptase HTLV-I=human T-cell lymphotropic virus type I IDL=intermediate density lipoprotein IL-3=interleukin-3 IRPs=iron regulatory proteins *Ki* =inhibition constant LD50=lethal dose at 50% LDL=low-density lipoprotein LIP=labile iron pool LPI=labile plasma iron MAO=monoamine oxidase MAPK=mitogen-activated protein kinase MDA=malondialdehyde MPTP=1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine MW=molecular weight NAD(P)+ =nicotinamide adenine dinucleotide phosphate NAD(P)H=reduced nicotinamide adenine dinucleotide phosphate ND=not determined NQO1=NAD(P)H:quinoneoxidoreductase 1 NTBI=non-transferrin bound iron ODC=ornithine decarboxylase 6-OHDA=6-hydroxydopamine PD=Parkinson's disease PPO=polyphenol oxidase RBC=red blood cell RNS=reactive nitrogen species ROS=reactive oxygen species SAM=*S*-adenosyl methionine

SULT=sulfotransferases T1/2β=beta-elimination half-lives TEAC=trolox-equivalent antioxidant capacity TK=tyrosine kinase TPA=12-*O*-tetradecanoylphorbol-13-acetate Treg=regulatory T cells UGT=uridine diphosphate-glucuronosyltransferase Vd=distribution volume VEGF=vascular endothelial growth factor WT=wild-type XO=xanthine oxidase
