TANNINS AND HUMAN HEALTH: Nutraceuticals effect of Tannin and its Monomers.

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• TANNINS AND HUMAN HEALTH Nutraceuticals effect
  of Tannin and its Monomers.

MAYANK TANDON DR. S.N. RAI Animal Nutrition
Division, National Dairy Research
Institute, e-mail mayanktandon1_at_gmail.com
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TANNINS

• Plant Tannins distinctive group of polyphenolic
  polymers of relatively high molecular weight
  (M.W 1000 to 20,000)
• Further categorized as HYDROLYSABLE tannins
  (HTs) or CONDENSED tannins (CTs or
  Proanthocyandins) on the basis of their structure
  and reactivity.

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• HTs are of low M.W (500-3000) and are polyesters
  of Gallic acid (gallo tannins) and
  hexahydroxy-diphenic acid (ellagitannins) with a
  central polyols such as sugars/glucose and
  phenolic such as catechin.
• CTs, M.W (1900-28000) have no carbohydrate core
  and comprise a group of polyhydroxy-flavan-3-ol
  oligomers and polymers linked by carbon-carbon
  bonds between flavanol subunits.

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TANNINS (Basic structure)
Hydrolysable Tannins

Condensed Tannins

Glucose
o
oH
oH
oH
oH
oH
o

oH
oH
oH
o
oH

o
o o
oH
o
o
o
OH
Glucose
oH
oH
OH
oH
OH
Gallotannins Ellagitannins

Catechin
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• Cardiovascular disease, principally heart disease
  and stroke, are the leading cause of mortality in
  both men and women in all racial and ethnic
  groups.
• The risk of atherosclerosis is increased by high
  blood pressure, hypertension, kidney disorders,
  obesity, diabetes, smoking, excessive alcohol
  consumption, stress, thyroid and adrenal gland
  problems, and lipid disorders
  
• (Crespy and
  Williamson 2004)

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• Tea contains many compounds, especially
  poly-phenols and epidemiologically studies show
  that polyphenolic compounds present in tea
  reduces the risk of a variety of diseases.
• Catechins are the main compounds in green tea
  they consist of (-)-epicatechin,
  (-)-epicatechin-3-gallate (ECg),
  (-)-epigallocatechin, (-)-epigallocatechin-3-galla
  te (EGCg) etc.
• 
  (Graham, 1992)

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• Monomers (catechin, epicatechin, gallic and
  ellagic acid) of Tannin present in red wine/
  green tea improve the antioxidative / immune
  status of the animals/ human.
• (Percival et al., 2002)
• Epidemiological studies shows that poly-phenolic
  compounds present in the Tea reduce the risk of a
  variety of diseases.

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THERAPEUTIC VALUES OF TANNIN METABOLITES

• Mice consumed wine rich in phenolic components as
  catechin, epicatechin, gallic acid, ellagic acid
  showed increased antioxidant activity.
• Gallic acid (GA) also showed strong antioxidant
  activity by preventing lipid per-oxidation.
• GA is a strong antioxidant that possesses
  antimutagenic and anticarcinogenic activities
• 
  (Shahrzad et. al., 2001)

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• Green tea contains
• () gallocatechin (GC),
• (-) epicatechin (EC),
• (-) epigallocatechin (EGC),
• (-) epicatechingallate (ECG),
• (-) epigallocatechingallate (EGCG)
• which shows numerous biological activities
  including antibacterial, antioxidant, anti-tumor
  and cancer preventive activities.
• Catechin serve as powerful antioxidant against
  lipid per oxidation when phospholipid bi-layers
  are exposed to aqueous oxygen radicals.

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• ()Catechin prevents cancer (liver, lung, breast
  and colon cancer) in at least one of three ways
• First, they can prevent the formation of
  carcinogens,
• Second, they tone up the body's natural
  detoxification defenses, and
• Finally, they suppress cancer promotion.
• ()Catechin has other promising qualities
• antibacterial and antiviral agent, regulating
  cholesterol and blood pressure, and reducing
  blood clotting tendencies that may cause heart
  attacks or strokes

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• NEUTRACEUTICAL EFFECTS OF CATECHIN AND
  EPICATECHIN
• Powerful Antioxidant effect prevent lipid
  peroxidation
• 
  (Terao et al., 1994).
• Antioxidant activity
• Scavenge free radicals and reduce
  oxidative stress.
• Enzyme induction and enhancing detoxification
• glutathione peroxidase
• catalase
• superoxide dismutase
• Catechin and epicatechin have Super Oxide
  Dismutase
• (SOD) like activity.
  (Kim et al., 1995)

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• Cont
• Prevent free radical induced RBC hemolysis.
• 
  (Zhang et al., 1997)
• Prevent coronary artery disease.
  
• 
  (Ishikawa et al., 1997)
• Inhibit the oxidation of LDL cholesterol,
  reduced
• body fat and thereby decrease incidence of
  heart
• disease.
• Catechins may stimulate the secretion of Bile
• salts and the fecal excretion of
  cholesterol.

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• EGCG inhibit phospholipid hydro peroxidation in
  plasma.
• Catechin have an anti-hyperglycemic action
  
  
  
  (Liu et al., 2005)
• Lowering blood glucose and normalizing insulin
  release.
• Prevent cancer (Valcic et al, 1996) prevent
  formation of carcinogen, increase the bodys
  detoxification mechanism against tumor inducing
  agents.

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• Inhibition of Onco-gene expression
• 
  (Liu, 2004)
• Gallic acid occurs as a free molecule or as part
  of a tannin molecule.
• GA is a strong antioxidant that possesses
  antimutagenic and anticarcinogenic activities
• 
  (Shahrzad et. al., 2001)

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Weight gain, food intake and liver weight of the
rates on control and powered green tea (PGT)
treatments. (Zhang, et al., 2002)
Measurement Control PGT (2 in DM)
No. of rats 10 10
Initial body weight, g 166.9 167.0
Body wt. gain, g /d 68.6 79.0
Food intake, g /d 14.78 15.69
Liver weight, g /rat 9.9 10.2
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Effect of dietary powered Green tea on serum
cholesterol level and Atherogenic Index (A) and
on serum triglyceride and lipid peroxide level
(B). (Zhang, et al., 2002)
A 1. Total cholesterol m mol / l 2. HDL - Ch 3.
VLDL LDL - Ch 4. Atherogenic index
B 1. Serum triglyceride 2. Serum lipid peroxide
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Plasma cholesterol, TG and oxidative state of
plasma lipoprotein in mice fed on atherogenic
diet with and without tea extract. (Miura, et
al., 2001)
Particular Time Control Tea group (3.2 mg /d)
No of mice 16 17
Body weight, g 0, wks 25.1 25.9
Body weight, g 14 23.4 26.5
Plasma cholesterol, m mol/ l 0, wks 14.6 14.6
Plasma cholesterol, m mol/ l 14 83.2 75
Plasma triglyceride, m mol /l 0 0.89 0.86
Plasma triglyceride, m mol /l 14 0.49 0.85
Plasma lipid peroxidase, µmol MDA /l 0 6.48 8.63
Plasma lipid peroxidase, µmol MDA /l 8 30.3 20.0
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Atheromatous area, aortic weights and aortic
lipid contents in mice fed an atherogenic diet
with and without tea extract.

(Miura, et al., 2001)
Particulars Control Tea group Reduction
Atheromatous area, 36.1 27.7 23
Aorta, mg 14.3 11.0 23
Cholesterol, µmol / aorta 0.830 0.610 27
Triglycerides , µmol / aorta 0.137 0.068 50
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Composition of Phenolic Compounds in Tea
extract(Miura, et al., 2001)
Catechins Mg/ g
(-)Epigallocatechin-gallate (EGCg) 584
(-) Epigallocatechin (EGC) 117
(-) Epicatechin (EC) 66
(-)Gallocatechingallate (GCg) 16
(-)Epicatechin-gallate (ECg) 5
Caffeine. 4
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• Varying level of Potency among Catechins.
• A in vivo experiment indicated that the
  components of tea catechins possess varying
  inhibitory effects on Cu2 - mediated oxidation
  of LDL in the following order
• EGCg gt ECg gt EC gt C gt EGC
• (Miura, et
  al., 1994 2001)

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Catalase protein expression in rats at 16 wks of
age that consumed water (control), Black tea
polyphenols, Green tea polyphenols for 3 wks
(Negishi, et al., 2004)
Extract was having tea Polyphenols 5 g /l of
water. And water consumption was 30 ml /d
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Catechin feeding effects on plasma TAS in rats
(pietta, et al.,
1998)
Treatment TAS (total antioxidant status), m moles/ l
Control 1.5 0.3
Catechin (2.1 g /l) 3.5 0.3
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Colon Cu-Zn SOD in rats given catechin (pietta,
et al., 1998)
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Composition of Phenolic Compounds in Muscadine
Wine
(Percival et al.,2002)
Mg/Liter
Muscadine Wine Total Phenols
834
Gallic acid
14
Ellagic acid
8
Catechin
5
Epicatechin
22 B3
procyanidin 0.3

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Total antioxidant capacity of plasma of mice
consuming red muscadine wine or ethanol
1 Muscadine wine
2 Ethanol (Percival et
al.,2002)
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• Catechins hypothesized to help protect against
  various diseases by contributing, along with
  antioxidant vitamins (i.e. Vit. C E) and
  enzymes (i.e. SOD and Catalase)
• In vivo studies show that green tea catechins
  increase total plasma antioxidant activity.
• Intake of Green tea extract also increases the
  activity of SOD in serum and the expression of
  catalase in the aorta.
• Malondialdehyde, marker of oxidative stress,
  decreases after Green tea intake

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• Catechins have a direct (antioxidant) or indirect
  (increase of activity or expression) effect.
• Because catechins can act as antioxidant in
  vitro, they might prevent the oxidation of other
  antioxidants, such as vitamin E.
• In some cases ingestion of green tea catechins
  does not modify the plasma status of vitamin E
  and C in vivo
• Catechins increase vitamin E concentration in LDL
  and in this way could protect LDL against
  peroxidation.

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Glucose concentration affected by Tannic acid

(Liu et al., 2005)
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• In an oral Glucose tolerance test in rats, tea
  catechins decreased plasma insulin levels but did
  not affect plasma glucose levels.
• In type 2 diabetes, lipid metabolism is modified
  Plasma and Liver triglyceride levels and plasma
  cholesterol levels are elevated, GTE intake
  reduced these values in rats fed a sucrose-rich
  diet.
• Catechins also reduced plasma TG levels.

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• Tannic acid (TA) induces glucose transport
  through activation of the Insulin-mediated
  signaling pathways in adipocytes.
• TA inhibited the expression of key genes for
  adipogenesis, and has an insulin-like glucose
  transport stimulatory activity in adipocytes.
• Epigallocatechin gallate (EGCG) enhances oral
  glucose tolerance in severely diabetic mice and
  in moderately diabetic rats.

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CONCLUSION

• Tannins its monomers have profound effects on
  health.
• Not advisable to take a large quantity of
  tannins, as they may be toxic.
• It is important to determine the correct dosage
  of tannins for promoting optimal health.