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JOURNAL OF CONTEMPORARY DENTAL SCIENCES VOLUME 1 ISSUE 1

REVIEW ARTICLE

BENIFICIAL EFFECTS OF POLYPHENOLIC BEVERAGE ON ORAL AND

PERIODONTAL HEALTH

SWETA SONI,MDS*,PRAMOD JAIN,MDS**, VIJAY KUMAR CHAUDHARY,MDS***

*SENIOR LECTURER, DEPARTMENT OF PERIODONTICS, VYAS DENTAL COLLEGE & HOSPITAL, JODHPUR, INDIA

** MEDICAL OFFICER,SMS HOSPITAL, JAIPUR, INDIA

***MEDICAL OFFICER, AMER, JAIPUR, INDIA

ABSTRACT

Periodontal diseases, if left unchecked, can lead to major health problems. There are a number of traditional

herbal remedies for the treatment and management of diseases related to periodontium and oral hygiene. Green tea has

long been used in much of the world as a popular beverage and a respected medicinal agent. Early Chinese medical

literature lists green tea as an antibacterial, astringent, antioxidant, anticaries, anti-inflammatory, circulatory-stimulant,

haemostatic, anti-halitosis. In recent years, there has been a significant upsurge in research on the characterization and

verification of the potential health benefits associated with the use of green tea. The use of green tea in promoting

gastrointestinal and cardiovascular health, use in prevention of cancer and neurodegenerative diseases and other

infectious conditions like periodontal disease. This review appraises the available evidence for and against the health

claims associated with green tea and its use as preventive and therapeutic products for periodontal disease. However,

considerable work is still needed to confirm these potential health benefits.

Key words: Green tea, Green tea catechins, Polyphenol, Periodontal disease, oral health.


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Introduction

Tea is considered the second most consumed

beverage in the world, next only to water and consumed in

different parts of the world as green, black, or Oolong tea.

Among all of these, however, the most significant effectson human health have been observed with the consumption

of green tea(1,2). Compared with black tea and Oolong tea

green tea is a non-oxidized and non-fermented product that

contains several polyphenolic components, also called

catechins, including epigallocatechin-3 gallate, epicatechin-

3 gallate, epicatechin, and epigallocatechin. Green tea

catechins have been shown to possess potent antioxidant

activity several times higher than that of vitamin C and

vitamin E(3).

McKay and Blumberg, 2002(4) reported a per capitamean consumption of tea in the world of 120 mL/ day.

Approximately 7678% of the tea produced and consumed

is black tea, 2022% is green tea and less than 2% is

oolong tea(5). Black tea is consumed principally in Europe,

North America and North Africa while green tea is widely

drunk in China, Japan, Korea and Morocco; oolong tea is

popular in China and Taiwan(5,6).

Green tea is used in several forms: consumed as

dilute infusion or concentrated supple or applied topically.

Commercial preparation use various extraction techniques

and manufacturing procedures and are not uniform. 2

Recently, the FDA approved a topical ointment con-

taining green tea extract as a prescription drug for the

treatment of genital warts(7).

Historical Context:

The tea plant, source of the most popular beverage

in the world, is believed to have originated in the landmass

encompassing Tibet, western China, and northern India.

According to ancient Chinese legend, tea was discovered

by the Chinese emperor Shen-Nung in 2737 B.C., when

leaves from a wild tea bush accidentally fell into a pot of

water he was boiling. The first recorded mention of tea

appears in a contract for slaves known as "Tan Yuch,"

written by Wang Pao, poet laureate to Emperor Husan, in

59B.C(8).

The word tea has been used to describe the shrub

Camellia sinensis . Tea plants produce abundant foliage, a

camellia-like flower, and a berry, but only the smallest and

youngest leaves are picked for tea-the two leaves and bud

at the top of each young shoot. The growth of new shoots,

called a flush(8).

Biochemistry of Green Tea:

Green tea chemical composition is complex:

proteins (15 20% dry weight) whose enzymes constitute

an important fraction; aminoacids (14% dry weight) such

as teanine or 5- N ethylglutamine, glutamic acid,

tryptophan, glycine, serine, aspartic acid, tyrosine, valine,

leucine, threonine, arginine, lysine; carbohydrates (57%

dry weight) such as cellulose, pectins, glucose, fructose,

sucrose; lipids as linoleic and linolenic acids; sterols as

stigmasterol; vitamins (B, C, E); xanthic bases such as

caffeine and theophylline, pigments such as chlorophyll

and carotenoids; volatile compounds as aldehydes,

alcohols, esters, lactones, hydrocarbons, etc.; minerals and

trace elements (5% dry weight) such as Ca, Mg, Cr, Mn,

Fe, Cu, Zn, Mo, Se, Na, P, Co, Sr, Ni, K, F and Al(8).

Green tea prepared in such a way as to preclude

the oxidation of green leaf polyphenols. The beneficial

effects generally associated with green tea have been

attributed to its polyphenol content, particularly to

catechins. Catechins are a group of very active flavonoids

that include (+)catechin, (+)gallocatechin, ()epicatechin

(EC) and ()epigallocatechin (EGC), and the galloyl

catechins such as ()epicatechin gallate (ECg),

()epigallocatechin gallate (EGCg), ()catechin gallate

(Cg) and ()gallocatechin gallate(GCg). EGCg is the most

abundant of these, comprising about 50% of the catechin

pool; EGC accounts for around 20%, ECg 13% and EC 6%.

Catechins are colourless, water-soluble compounds that

contribute to the bitterness and astringency of green tea. A

typical green tea serving contains approximately 90mg

catechins(9).

Bioavailability of Green Tea Catechins

The potential health effects of catechins depend not

only on the amount consumed but on their bioavailability


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which appears to be very variable. In order to know the

catechin bioavailability and metabolism, it is necessary to

evaluate their biological activity within target tissues. 10

Following oral administration of tea catechins to rats, the

four principal catechins (EC, ECG, EGC, and EGCG) have

been identified in the portal vein, indicating that tea

catechins are absorbed intestinally(11). Green tea catechins

have been shown to be bioavailable in human, with EGCG

showing lower bioavailability than EGC and EC(12). Only

a small percentage of the ingested catechins appear in the

blood. In a study by Lee et al,2002(12), at the time point

tmax ( the time reach maximum concentration), 0.16,0.58,

and 1.1% of the ingested doses of EGCG, EGC and EC

from green tea administration were present in the

circulating plasma. According to different studies on

catechin pharmacokinetics, EGCG are mostly present in the

free form in the plasma, whereas EGC and EC are

predominantly found as glucuronic acid and sulphate

conjugates in plasma and urine. There is evidence that

EGCG is only present in trace or non-detectable amounts

in the urine and is excreted in to bile(12,13).

Further research results are largely consistent in

demonstrating that the addition of milk to tea does not

interfere with catechin absorption(14-16), but milk may

affect the antioxidant potential of tea, depending upon milk

fat content, milk volume added, and the method used to

assess this parameter(14-16). Xu et al .(17) observed that

the epimerization reaction occurring in manufacturing

canned and bottled tea drinks would not significantly affect

antioxidant activity and bioavailability of total tea

polyphenols.

Oral Health and Green Tea:

Earlier epidemiological studies reported that

populations who drink tea on a regular basis have a reduced

number of carious teeth(18). The tea plant extracts fluoride

from the soil, which then accumulates in its leaves. For this

reason tea is a very rich natural source of fluoride; dry tea

leaves may contain 4-400ppm fluoride, the brewed tea

0.34-6ppm resulting in one cup of tea containing between

0.3mg and 0.5mg of fluoride(19-21). Several mechanisms

have been proposed for the observed anticariogenic

properties of tea and its polyphenols. This includes

inhibitory effect on bacterial growth and bacterial viability,

inhibition of glucosyl transferase which limits the

biosynthesis of sticky glucan (glucan synthesis allows the

bacteria to firmly attach to the tooth surface), and inhibition

of salivary -amylase activities and the consequent

inhibition of starch hydrolysis(22). In a few human trials,

catechins (without added sugar) have been shown to inhibit

plaque deposition(23) reduce plaque and gingival index(24)

and inhibit acid production in dental plaque bacteria(25).

Also, it has been shown that green tea was very effective in

reducing oral malodour temporarily because of its

disinfectant and deodorant activities(26).

It has been suggested that tea may play a role in the

prevention of oral cancer(27). One double-blind,randomised intervention trial suggested that treating

patients with a mixture of black and green tea components

could improve the clinical manifestations of precancerous

oral lesions(28). A pilot study showed that heavy smokers

who consumed 5 cups of green tea a day for four weeks

reduced the number of damaged cells in the mouth. The

authors concluded that these results warrant a large scale

intervention trial to further verify the role of green tea in

the prevention of oral cancer in smokers(29).

Green Tea as a Preventive and Therapeutic Product in

Periodontal Disease:

Oxidative stress plays an important role in the

pathogenesis of periodontal disease, as well as many other

disorders(30). Antioxidants such as polyphenols in green

tea can neutralize free radicals and may reduce or even help

prevent some of the damage they cause. Makimura M,

1993(31) investigated the effect of various tea polyphenol

and caffeine on induction of NO synthetase (NOS) in

thioglycollate elicited and lipopolysaccharide(LPS)-activated peritoneal macrophages. EGC and EGCg found to

be inhibit inducible NOS protein (iNOS) in activated

macrophages, and reduction could occur through

prevention of the binding of nuclear factor kappa-B to the

iNOS promoter, thereby inhibiting the induction of iNOS

transcription. Moreover, there is consistent evidence that


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green tea consumption produces a significant increase in

the overall plasma antioxidant capacity in humans(32-34).

Green tea extracts and catechins are known to have strong

antioxidant properties in vitro(34). In various in-vitro

tests, catechins are able to protect biological molecules e.g.

endogenous antioxidants, lipids, and proteins, against the

adverse effects of reactive oxygen and reactive nitrogen

species(35-38). It has been reported that a dentifrice

containing green tea catechins was effective in inhibiting

gingival oxidative stress in periodontal lesions(39). Topical

green tea catechins may also be an effective therapeutic

agent, acting to suppress periodontal inflammation with

decreasing gingival oxidative stress(39).

There have been reports showing that the (-)-

epigallocatechin gallate ( EGCg), which is a predominant

component of Japanese green tea catechins, exhibited a

number of inhibitory effects on bacteria, tumor cells, and

the hosts immune systems. The bactericidal effects of tea

catechins on pathogenic bacteria, such as Escherichia

coli(40), Helicobacter pyroli(41), and methicillin-resistant

Staphylococcus aureus(42), were demonstrated by their

ability -

to damage the bacterial lipid bilayer, to inhibit bacterial enzymatic activities,

and

to bind directly to peptidoglycan, as

observed with beta lactams.

Mouth rinsing with a dilute catechin solution

reduced the mouth odour (halitosis) associated with

periodontal disease; it was subsequently established that tea

catechins deodorized methyl mercaptan, the main cause of

halitosis(43).

Green tea catechins, such as (-)-epigallocatechin

gallate (EGCg), inhibit periodontal pathogens and inhibited

the collagenase activity at optimal concentration of teacatechin (50 to 100 mg/ ml)(44). Green tea poly phenol

such as catechin gallates, especially EGCg (active at 250

500 g/ml), inhibited growth and adherence to buccal

epithelial cells of P. gingivalis(45).

Green tea catechins and related polyphenols

inhibited the activity and expression of collagenase of

gelatinase (MMP-2 and MMP-9) further it has been

reported that EGCg and its derivatives inhibit protein-

tyrosine phosphatase activity in prevotella intermedia(46).

The green tea catechins produced bactericidal activity at 1

mg/ml concentration against species of Prevotella and P.

gingivalis , and reduction in markers of gingivitis after the

use of a slow-release buccal delivery system applied over a

period of 8 weeks(25). More recently, the effects of the

EGCg and its derivatives from Japanese green tea on the

activities of Rgp and Kgp in P.gingivalis investigated, and

the findings suggest that green tea catechins may have the

potential to reduce periodontal breakdown resulting from

the potent proteinase activity of P.gingivalis. 47 EGCg and

epicatechin gallate inhibited lactate dehydrogenase and

effective in reducing acid production in dental plaque and

mutans streptococci(25).

Recently, Mitoshi Kushiyama, 2009(48)

investigate the relationship between the intake of green tea

and periodontal disease. In multivariate linear regression

models, every one cup/day increment in green tea intake

was associated with decrease in the mean probing depth,

decrease in the mean clinical attachment level and decrease

in bleeding on probing Further more J. Prabhakar, 2010(49)

investigate the antimicrobial efficacy of Triphala, green tea

polyphenols, MTAD(a mixture of doxycycline, citric acid,

and Tween-80 detergent), and 5% sodium hypochlorite

against E. faecalis biofilm formed on tooth substrate. 5%

sodium hypochlorite showed maximum antibacterial

activity against E. Faecalis biofilm formed on tooth

substrate. Triphala, green tea polyphenols and MTAD

showed statistically significant antibacterial activity.

Alveolar bone resorption is a characteristic

feature of periodontal diseases and involves the removal of

both the mineral and organic constituents of the bone

matrix, which is caused by multinucleated osteoclast cells.

It has been reported that (-)-epigallocatechin gallate could

induce the apoptotic cell death of osteoclast(50). Yun J-

H,et al 2007(51) has been found that EGCG inhibited the

osteoclast formation induced by 1-alpha,25(OH)2D3 ,

investigation based on TRAP staining in the co-culture

system. Finding suggest that EGCG remar kably reduced

the number of TRAP-positive multinucleated cells at a


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concentration of 20 uM. Yun J-H,et al 2007(52) further

suggest that (-)-epigallocatechin gallate might prevent

alveolar bone resorption by inhibiting osteoclast survival

through the caspase-mediated apoptosis.

Harmful Effects of Green Tea:

Although green tea has several beneficial effects on

health, the effects of green tea and its constituents may be

beneficial up to a certain dose yet higher doses may cause

some harmful effects. Harmful effects of tea over-

consumption are due to three main factors: its caffeine

content, the presence of aluminum, and the effects of tea

polyphenols on iron bioavailability. Green tea should not

be taken by patients suffering from heart conditions or

major cardiovascular problems. Pregnant and breastfeeding

women should drink no more than one or two cups per day,

because caffeine can cause an increase in heart rhythm. It is

also important to control the concomitant consumption of

green tea and some drugs, due to caffeines diuretic

effects(53). Some studies revealed the capacity of tea plants

to accumulate high levels of aluminum. This aspect is

important for patients with renal failure because aluminum

can be accumulated by the body, resulting in neurological

diseases; it is therefore necessary to control the intake of

food with high amounts of this metal. Likewise, green tea

catechins may have an affinity for iron, and green tea

infusions can cause a significant decrease of the iron

bioavailability from the diet(55).

Conclusion:

Various studies suggest that there is a modest

association between daily intake of green tea and its

preventive role. Drinking green tea at meals is a relatively

easy habit to maintain a healthy periodontium. Definitive

conclusions concerning the protective effect of green tea

have to come from well-designed observational

epidemiological studies and intervention trials. The

development of biomarkers for green tea consumption, as

well as molecular markers for its biological effects, will

facilitate future research in this area.

Corresponding author: Dr. Sweta Soni, Senior Lecturer,

Department of Periodontics, Vyas Dental College and

Hospital, Jodhpur, India. Phone: +91 9414915087, Email:

[email protected]

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