Illn

ess

sugg

este

d to

be

asso

ciat

edwi

th oxi

dative

str

ess

Eye Brain

Chest

Lower abdomen

Abdomen

Body

Air tubeFace

RadiationUV radiation

Smoking

Air pollutants

Agriculturalchemicals

Additives

DetergentsActivated oxygen

Free radicals

AntioxidantsVitamin EVitamin Cβ-Carotene

FlavonoidsUbiquinone

Scavenging

http://www.hsrmagazine.com/articles/2c1specialty2.htmlORAC=Oxygen Radical Absorbance Capacity

Blackcurrant

Strawberry

Raspberry

“Antioxidants! Antioxidants!….”

WomenMen

50

40

30

20

10

01994 1995 1996 1997 1998 1999 (ป ค.ศ.)

42.1845.62

41.16

27.9726.77

20.920.0820.09

18.7116.06

14.42

11.72

Year 1994 1995 1996 1997 1998 1999

% 11.9 19.7 13.2 24.1 29.3 30.6

รอยละของการเกิดผลเสียจากการใชผลิตภัณฑฯ

การใชผลิตภัณฑเสริมอาหารของผูสูงอายุที่รวมในกลุมthe New Mexico Aging Process Study

Wold et al.,J Am Diet Assoc, 2005;105:54-63.

1.Generation of free radicals, oxidative stress& their’s damaging effects: ศ.ดร.ไมตรี สุทธจิตต

4.Antioxidants in cosmetics:รศ.ดร.พรรณวิภา กฤษฏาพงศ

3.Antioxidants in neurodegenerativedisorders: รศ.ดร.จินตนา สัตยาศัย

2.Antioxidants in metabolicdisorders: รศ.ดร.วีรพล คูคงวิริยพันธ

รศ.ดร. จินตนา สัตยาศัยภาควิชาเภสัชวิทยาคณะแพทยศาสตรมหาวิทยาลัยขอนแกน

•สมองมีปริมาณไขมันไมอิ่มตัว (PUFAs) เปนจํานวนมากทําใหไวตอภาวะเครียดทางออกซิเดชัน

•สมองใชออกซิเจนในอตัราที่สูงมาก จึงมีการปลอย oxidants ออกจาก neural mitochondrial และสราง superoxide anion ไดมาก •ปริมาณของ Antioxidant enzymes ใน extracellular space มีนอย:

-SOD ใน neurons-GSH และ GPX (peroxidases) ใน astrocytes-activity ของ Catalase และ GSH-Px มีต่ํา

•Oxidative stress เกดิขึ้นไดโดยหลายกลไก เชน-การเพิ่ม intracellular free Ca2+

-การหลั่ง excitatory amino acids (Glutamate)***

CNS และ Oxidative stress

(GSH=glutathione;GSH-Px=glutathione peroxidase)

Reactions important in the production anddefense from reactive species in neurons

O2 + e- O2-. H2O2 + O2

SOD

2H+

OH. + OH- + Fe3+

(Fenton Reaction)

Fe2+/Cu+

R. (organic radical)

RH (organic compound)

RO2 (peroxy radical)O2

ONOO-

NO2+

Nitration ofresiduetyrosine

O2 + OH- + OH.

(Haber-Weissreaction)

.NO2 + OH.

H2O + O2H2O + O2

GSH-Px GSH-RedGSSG

GSH

Catalase

SOD

H2O2

NO.

Fe2+ + O2

Fe3+

GSH-Px = glutathione peroxidase; SOD=super oxide dismutase;GSSH = glutathione disulfide; ONOO-=peroxynitrite;GSH = glutathione; O2

-.=superoxide species;GSH-red = glutathione reductase; OH.=hydroxyl species

Junk Food

Anti-oxidantmenu

ลูกจา มากิน antioxidants เพื่อจะไดลดการทําลายเซลลสมองที่เกิดจาก oxidants ใน junk food

GluNMDANMDAR1/NMDAR2Ahigh Mg2+ sensitivity

-mGluR-II,III(basal negative feedback)

+ mGluR-I

mGluR-I+

AMPA

Nitric oxide (NO) as-an intercellular messenger

-an atypical neurotransmitter

In neurotransmitterrelease

As neurotoxinPAF-R

PAFHigh Ca2+

Long term potentiation(LTP)

Ca2+ mediated signals

-การเรยีนรู และความจํา-neuroplasticity, etc.

Ca2+ NO

H2O2 enhanced NMDA-dependentLTP in hippocampus

Synaptic plasticity

(Kamsler & Segal, 2003)

Functions of brain plasticity -Brain development-Learning & memory-Psychiatric disorders-Neurological disorders

H2O2, a membrane-permeable form of ROS,normally produced in living cells and synapses.

Hydrogen peroxide (H2O2)

Aging TraumaStrokeParkinson’s disease (PD)Huntington’s disease (HD)Alzheimer’s disease (AD)Amyotrophic lateral sclerosis (ALS)Multiple sclerosis (MS)

Heart

Joints

LungMulti-organ

Vessels

GI

Eye Kidney Skin

OXIDATIVE STRESS

Brain

Degenerative retinal damageCataractogenesis

Renal graftGlomerulonephritis

Ischemic bowelLiver injury

VasospasmAtherosclerosis

AgingCancerDM

AsthmaHyperoxia

Rheumatoid arthritis

BurnDermatitisPsoriasis

Infarction

(From Calabresi et al.,2003)

Aging, Trauma & Stroke

Na+-K+-pump failure

Membrane depolarization

Opening of voltage-sensitive Ca2+ channels

Elevation of intracellular Ca2+ levels

Glutamate release

Activation of NMDA,AMPA& metabotropic receptors

StrokeReduction of blood flow (ischemia/hypoxia)

Depletion of energy stores

Activation of NOsynthase,lipases,proteases andendonuclease

Apoptosis Irreversible cell damageCELL DEATH

Acidosis

Reperfusion

Inflammation

Release of cytokines

Failure of Ca2+

buffering sys-tems and pumps

AgingOther factors

NO production

Free-radicalformation

Lipid peroxidation

(Mandel et al., 2003)

Nitric oxide

Release offerritin iron

Reduction in ubiquitin-proteosome system

Proteinaggregation

Neuronaldeath

Biochemical events associated withneurodegeneration of DAneurons in PD

Glutamate excitotoxicity

neurotoxins

Impaired cellularrespiration

Iron accumulation, oxidativestress & inflammation

Parkinson’s Disease

Alzheimer’s Disease

Aβ generation

Oxidation Excito-toxicity

Aβ aggre-gation

Inflam-mation

Tau hyper-phosphorylation

Cognitive& behavioralabnormalities-Neurotransmitter

deficit,-Loss ofneuroplasticity

Senile plaque withmicroglial activation

Neurofibrillarytangles

β secretase α secretase

Non amyloidogenicpathway

Amyloidogenicpathway γ secretase γ secretase

Aβ

Celldeath

(Gamblin et al., 2000)

Reactive Oxygen Species

Amyotrophic Lateral Sclerosis

(Eisen, 2000)

Free Radical Damage to Motor Neurons

Hydrogenperoxide

Oxygen radical

Environmental factors Genetic factors

ROSproduction Macrophage

Excitotoxicity Transcription factors

Glutamate

Demyelination Gene upregulation (I.e., TNF-α) Axonal damage

Oligodendrocyte and neuronal loss

Sources of ROS & cellular events in MS

Multiple Sclerosis

(Gilgun-Sherki et al., 2004)

Cellular Pathogenesis in HD

•Antioxidant vitamins•Plant polyphenols•Human endogenous ligands•Female sex hormone: Estrogen& Phytoestrogens

Antioxidant vitamins

Ascorbic acid(vit C)

Alpha-tocopheral(vit E)

Antioxidants Pro-oxidantsNeuroprotectants

•Both Vit C & E do notreduce risk of dementiaor PD(CNS Drugs 2003;Cummings,N Engl J Med 2004)

•Vit E but not Vit Ccould have a role in ALSprevention: clinical trials(Ascherio et al., Ann Neurol 2005)

•Potentiate extrapyramidaleffects of haloperidol & NOS inhibitors (Lazzarini et al., Psychopharmacol,2005)

•Vit C: Hb denaturation in G-6-PD def. (Papandreou & Rakitzis, 1990)

•Vit E: antioxidative enzymes in erythrocytes (Eder et al., 2002)

Vitamin A & beta-carotene

(Ono et al., Exp Neurol 2004)

retinol = retinal > beta-carotene > retinoic acid.

Vitamins B2, B6, C, and E at50 and 100 µM

had no inhibitory effect

Antiamyloidogenic activity(in cell culture)

Electronmicrographof fibril extension

Control: 0 h Control: 6 h +retinol: 6 h

-Ginkgo biloba (EGb)-Catechins -Caffeic acid phenethyl ester

(from honeybee’s propolis)

Ginkgo biloba (EGb)แปะกวย

Free radical scavengersFlavonoidsEgb had small but significant effect in AD patients

(Cummings, N Engl J Med 2004)

EGb=Gingko biloba extract3 wks pretreatment

Control

10 µg 6-OHDA +50 mg/kg EGb

+100 mg/kg EGb +150 mg/kg EGb

(Ahmad et al., J Neurochem, 2005)

The expression of tyrosinehydroxylase (DA neuron) in

substantia nigra of rat (PD model)

•antioxidant•free radical scavenging•MAO-B inhibiting•DA-enhancing mechanisms

Rescue the DA neurons(PD model)

CatechinsCamellia sinensis

A group of flavonoids; ~30-45% ofthe solid green tea extract

(-)-epigallocatechin-3-gallate (EGCG)(-)-epigallocatechin (EGC)

(-)-epicatechin (EC)(-)-epicatechin-3-gallate (ECG)

~10%

EGCG: modulation of cell death genein Parkinson’s model

(Mandel& Youdim, Free Rad Biol Med 2004)

EGCG=potential candidatefor the treatment of

neurodegenerative disorders50mg/kg EGCG i.p., after ischemia;rats were killed 72h post ischemia.

(Rahman et al., Neurosci Lett 2005)

EGCG as an interventionof cerebral ischemia

Infa

rc S

ize

(mm

3 )

Antioxidant prop.EGCG=ECG>EGC>EC

Caffeic acid phenethyl ester(CAPE)

Active antioxidant flavonoids (45-55%)from honeybee propolis

Cultured cerebellargranule neurons (CGN)

red fluorescent=death neuron

Control

6-OHDA

6-OHDA+ CAPE Effect of CAPE (µΜ) on

Ca2+-induced Cyt-C releasein rat liver mitochondria

(Noelker et al., Neurosci Lett 2005)

Propolis = neuroprotectant; a goodcandidate for in vivo models

Model for MS: oral flavonoids fail tobeneficially influence the course of EAEin mice but, instead, suppress recovery

from acute inflammatory damage.(flavonoids tested-apigenin, luteolin,

quercetin, hesperitin, morin,fisetin & curcumin)

Biochemical Pharmacology 70 (2005) 220-228

Human endogenous ligands

Coenzyme Q10 (ubiquinone)

=important antioxidant in bothmitochondria and lipid membrane

Slow down functional decline in PD patients(Frucht, CNS Drugs 2005)

Protect DA neuronal death from pesticide rotenone(Moon et al., J Neurochem 2005)

360mg/day: therapeutic effect in HD patients(Korozhetz et al., Ann Neurol 1997)

Coenzyme Q10 has the potentialto be used as a therapeutic

intervention for neurodegenerativediseases.

(Somayajulu et al., Neurobiol Dis 2005)

α-Lipoic acid (α-LA)A biological antioxidant , cofactor in many

mitochondrial reactions

EAE= experimental autoimmuneencephalomyelitis; a model

for MS

(Morini et al., J Neuroimmunol 2004)

α-LA=a potential therapy for MS(mechanisms other than its

antioxidant activity)

Melatonin

(Hardeland & Pandi-Perumal, Nutr Met 2005)

Natural compound of almost ubiquitous occurrence

AMK=Melatonin metabolite

Therapeutic trials with melatonin:slowing the progression of AD but not of PD.

(Srinivasan et al., Neurotox Res 2005)

(Ozdemir et al.,Neurosci Lett 2005)

CA1

CA3

DG

Melatonin protect hippocampus from theeffect of traumatic Brain Injury

Female sex hormone: Estrogen& Phytoestrogens

(Amantea et al., Pharmacol Res, 2005)

Modulation ofgene

transcription

Inhibition ofcell death

Anti-inflammatoryactivity

Neurotrophiceffects

Estrogen receptors(intracellular)

-ERα-ERβ

Interaction withneurotrophin

signal transductionpathways

Rapid non-genomicintracellularresponses

Modulation ofneurotransmitter

systems

Neurotrophinreceptors

Membranebinding sites

Neurotransmitterreceptors

Antioxidanteffects

Estroge & Brain PlasticityEstrogen supplement

increase dendritic knobEstrogen

supplement Control

Rat’s brain: cognitive area

Estrogen Replacement Therapy:risk (uterine & breast cancer) VS benefit?

A brain selective estrogenreceptor modulator

(NeuroSERM) (Brinton, 2004)

A non-feminizing estrogen,2-(1-adamantyl)-4-

methylestrone (ZYC-26)(Perez et al., 2005)

ERT

Phytoestrogens=natural SERMs

Pueraria mirifica (กวาวเครือ) :isoflavonoids

Soy isoflavones:Genistein, Daiazein,Glycitein etc.

Caenorhabditis elegans (C. elegans)

Soy isoflavone glycitein protects against betaamyloid-induced toxicity and oxidative stress in transgenic

Caenorhabditis elegans. Gutierrez-Zepeda et al., BMC Neurosci 2005

Glycitein

May have therapeutic potentialfor prevention of Aβ associatedneurodegenerative disorders

Main results-No significant effect on theprimary outcome measure wasobserved in a meta-analysis ofantioxidants in general whencombining the results.-No significant differenceswere demonstrated in secondaryoutcome measures

Author’s conclusion-While there is no substantialclinical trial evidence to supporttheir clinical use, there is no clearcontraindication.

The Cochrane Library2005, Issue 3

Antioxidant treatment for ALS

Antioxidant treatment for HDAntioxidant efficacy was not observed

in human clinical trial. Studies havebeen planned for other free-radicalscavengers. (Gardian & Veesei, J Neural Trans 2004)

Antioxidants and neurology

Clinical evidence that antioxidants agentsmay prevent or slow the course of thesediseases is still relatively unsatisfactory,

and unsufficient to strongly modifythe clinical practice.

(Casetta et al., Curr Pharm Des. 2005)

Normal neurons Damaged neurons

Neuronal Cell Death

Oxidants & Neurodegenerative disorders

Free radicals cellular defence mechanism-enzymes: SOD, Catalase-others: vit.C, vit.E

Oxidative metabolism-(PD) DA DOPAC

MAO-B

.OH + OH-

-Inflammation(MS)

Abnormal proteins-Alzheimer’s disease & β amyloid-Prion protein & Prion disease (Mad cow)

Excitotoxicity(Trauma, Stroke, Aging)

Genetic defect:e.g. Mutation ofSOD1 & ALS

Oxidative stress

mismatch

Mitochondrial dysfunction& cell damage

Energy deprivation& Cell death

VDAC=Voltage dependent anion channelANT=Adenosine nucleotide translocasePBR=Peripheral benzodiazepine receptorCK=Creatinine kinaseCyD=Cyclophilin D

EGCG polyphenols

(Mandel & Youdim,Free Rad Biol Med 2004;Weinreb et al., J NutrBiochem 2004))

Radical scavengingIron chelation

Increasing antioxidant defense

Green Tea Polyphenols

Neurotoxin-inducedROS

PKC ANTVDAC

COMT

Apoptotic genes Aβ fibrils

NEUROPROTECTION

sAPPα

?

?

X

Suggested potential targets of EGCG