Oxida i e s ess in neu odegene a ion: in i o
models o in es iga ing cellula damage and
neu op o ec i e s a egies
Alime Ga ip1, Deni sa S e ano a1, Vi ginia Tzanko a1
1 Depa men o Pha macology, Pha maco he apy and Toxicology, Facul y o Pha macy, Medical Uni e si y o So ia, So ia, Bulga ia
Co esponding au ho :
Alime Ga ip (alime_1999@ab .bg)
Recei ed
17 Oc obe 2025♦
Accep ed
24 Oc obe 2025♦
Published
24 No embe 2025
Ci a ion:
Ga ip A, S e ano a D, Tzanko a V (2025) Oxida i e s ess in neu odegene a ion: in i o models o in es iga ing cellula
damage and neu op o ec i e s a egies. Pha macia 72: 1–12. h ps://doi.o g/10.3897/pha macia.72.e175265
Abs ac
Neu odegene a i e diso de s such as Pa kinson’s disease (PD) a e d i en by complex and mul i ac o ial mechanisms, among which
oxida i e s ess plays a cen al pa hogenic ole. A sus ained imbalance be ween eac i e oxygen species (ROS) p oduc ion and an i-
oxidan de enses con ibu es o mi ochond ial dys unc ion, lipid pe oxida ion, and dopamine gic neu onal loss. This e iew ocuses
on oxida i e s ess-induced neu odegene a ion and explo es how in i o models can be e ec i ely used o s udy he cellula conse-
quences o oxida i e damage. Pa icula emphasis is placed on oxin-based models, including 6-hyd oxydopamine (6-OHDA) and
1-me hyl-4-phenylpy idinium (MPP+), as well as cellula sys ems such as immo alized cell lines, p ima y neu ons, and induced plu-
ipo en s em cell (iPSC)-de i ed neu ons. The applicabili y, ad an ages, and limi a ions o each model a e discussed in he con ex o
mimicking PD- ela ed oxida i e damage and sc eening o neu op o ec i e s a egies. Ul ima ely, his e iew unde sco es he impo -
ance o selec ing app op ia e in i o models o dissec ing oxida i e s ess pa hways and ad ancing neu op o ec i e esea ch in PD.
Keywo ds
in i o, neu op o ec ion, oxida i e s ess, Pa kinson’s disease, oxin-based models
In oduc ion
Pa kinson’s disease (PD) is he second mos common neu-
odegene a i e diso de a e Alzheime ’s disease, a ec -
ing app oxima ely 1–2% o indi iduals o e he age o 65
(Tysnes and S o s ein 2017). I is clinically cha ac e ized by
he p og essi e loss o dopamine gic neu ons in he sub-
s an ia nig a pa s compac a and he accumula ion o Lewy
bodies, composed mainly o mis olded and agg ega ed
α-synuclein (Daue and P zedbo ski 2003; Shulman e al.
2011). Al hough he exac e iology o PD emains unclea ,
a combina ion o gene ic p edisposi ions and en i onmen-
al exposu es con ibu es o disease onse and p og ession
(Wa ne and Schapi a 2003; Simon e al. 2020).
Se e al gene ic mu a ions ha e been iden i ied in amil-
ial and spo adic o ms o PD, including hose in SNCA,
LRRK2, PARK2, PINK1, and DJ-1 (Alexande 2004; Rui e
al. 2018). Howe e , monogenic causes accoun o only a
mino i y o cases, and he majo i y a e conside ed idiopa h-
ic. Inc easing e idence sugges s ha oxida i e s ess plays
a cen al ole in he pa hogenesis o bo h amilial and spo-
adic PD (Zhou e al. 2008; Gaki and Papa assiliou 2014).
Oxida i e s ess a ises om an imbalance be ween e-
ac i e oxygen species (ROS) p oduc ion and he cellula
an ioxidan de ense sys ems. Dopamine gic neu ons a e
pa icula ly ulne able due o hei high me abolic de-
mand, dopamine au ooxida ion, abundan mi ochond ial
ac i i y, and ele a ed i on le els—all o which p omo e he
Copy igh Ga ip A e al. This is an open access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion License
(CC-BY 4.0), which pe mi s un es ic ed use, dis ibu ion, and ep oduc ion in any medium, p o ided he o iginal au ho and sou ce
a e c edi ed.
Pha macia 72: 1–12
DOI 10.3897/pha macia.72.e175265
Re iew A icle
Ga ip A e al.: In i o models o oxida i e s ess in neu odegene a ion2
gene a ion o ROS (Ozcan and Ogun 2015; Bu bulla e al.
2017). These ROS can induce damage o DNA, p o eins,
and lipids, con ibu ing o neu odegene a ion and neu o-
nal dea h (Zhang e al. 1999; Floo and We zel 2002).
Gi en he complexi y o PD pa hogenesis, he use o in
i o models has become an essen ial s a egy in expe i-
men al neu oscience. These models o e a con olled en-
i onmen o dissec molecula mechanisms in ol ed in
PD, such as mi ochond ial dys unc ion, α-synuclein ag-
g ega ion, glu ama e exci o oxici y, and edox imbalance
(Lopes e al. 2017; Xicoy e al. 2017). Mo eo e , in i o
sys ems allow o high- h oughpu sc eening o neu op o-
ec i e agen s and mechanis ic s udies o cell dea h and
su i al, acili a ing he de elopmen o po en ial he a-
peu ic s a egies (No abe g e al. 2005; Soldne e al. 2009).
This e iew aims o p esen an in eg a ed o e iew o
he molecula mechanisms unde lying Pa kinson’s dis-
ease, wi h an emphasis on oxida i e s ess, lipid pe oxida-
ion, and an ioxidan de ense. Special a en ion is paid o
in i o models commonly used in PD esea ch, e alua -
ing hei ad an ages, limi a ions, and ele ance o s udy-
ing PD-associa ed neu o oxici y and neu op o ec ion.
Oxida i e s ess and
mechanisms o dopamine gic
neu odegene a ion in
Pa kinson’s disease
Oxida i e s ess is ecognized as a pi o al ups eam e en in
he pa hogenesis o Pa kinson’s disease (PD), con ibu ing
signi ican ly o he selec i e degene a ion o dopamine gic
neu ons. I a ises om an imbalance be ween he excessi e
gene a ion o eac i e oxygen species (ROS) and he limi ed
capaci y o endogenous an ioxidan de enses. The subs an-
ia nig a pa s compac a (SNpc)— he p ima y si e o dopa-
mine gic neu on loss—is pa icula ly suscep ible o oxida-
i e insul s due o i s high me abolic ac i i y, abundan i on
con en , and he in insic edox ulne abili y o dopamine -
gic neu ons (Gaki and Papa assiliou 2014; Bu bulla e al.
2017). This oxida i e bu den p omo es a cascade o cellula
damage, including mi ochond ial dys unc ion, p o ein mis-
olding, lipid pe oxida ion, and ul ima ely, neu onal dea h.
Molecula sou ces o ROS in PD
Mi ochond ia ep esen he majo sou ce o ROS wi hin
neu ons, pa icula ly unde condi ions o impai ed oxi-
da i e phospho yla ion. In PD, complex I (NADH:ubiqui-
none oxido educ ase) ac i i y is equen ly comp omised
in he SNpc, leading o inc eased elec on leakage and
he o ma ion o supe oxide anions (O₂•–) (Schapi a e al.
1990). These adicals a e subsequen ly dismu a ed o hy-
d ogen pe oxide (H₂O₂), which, in he p esence o e ous
i on, unde goes Fen on chemis y o yield hyd oxyl adicals
(•OH)—among he mos cy o oxic ROS (Ozcan and Ogun
2015). Age- ela ed espi a o y de iciencies, mi ochond ial
DNA mu a ions, and impai ed elec on anspo u he
exace ba e ROS p oduc ion, es ablishing a icious cycle o
oxida i e s ess and bioene ge ic ailu e. No ably, dopami-
ne gic neu ons exhibi heigh ened dependence on mi o-
chond ial ATP gene a ion, which ampli ies hei suscep i-
bili y o edox-d i en inju y (Gandhi and Ab amo 2012).
A summa y o he majo endogenous sou ces o ROS,
hei mechanisms o gene a ion, and associa ed cellula
consequences con ibu ing o dopamine gic neu odegen-
e a ion in PD is p esen ed in Table 1.
Beyond mi ochond ial sou ces, dopamine me abolism
i sel cons i u es a signi ican con ibu o o oxida i e
s ess. Unde no mal condi ions, dopamine is seques e ed
in o synap ic esicles ia esicula monoamine anspo -
e 2 (VMAT2), minimizing cy osolic oxida ion. In PD,
impai ed VMAT2 unc ion and ele a ed cy osolic dopa-
mine le els p omo e dopamine au oxida ion, gene a ing
eac i e quinones and H₂O₂ (Has ings e al. 1996).
Dopamine-quinones co alen ly modi y hiol g oups
on cys eine- ich p o eins, dis up ing p o ein unc ion and
enhancing α-synuclein agg ega ion (Bu bulla e al. 2017).
Addi ionally, enzyma ic deg ada ion o dopamine by mono-
amine oxidase B (MAO-B) u he con ibu es o H₂O₂ ac-
cumula ion, compounding he oxida i e bu den. This dual
pa hway o dopamine oxida ion—bo h enzyma ic and spon-
aneous—plays a cen al ole in dopamine gic ulne abili y.
I on dyshomeos asis in he SNpc ep esen s ano h-
e c i ical d i e o oxida i e neu odegene a ion in PD.
Pos mo em analyses consis en ly e eal ele a ed le els
o edox-ac i e Fe²+ in PD b ains, pa icula ly in egions
a ec ed by dopamine gic loss (Dex e e al. 1989; Wa d e
Table 1. Majo molecula sou ces o ROS and hei consequences in Pa kinson’s disease.
Sou ce o ROS Mechanism o gene a ion Key molecules / enzymes Main consequences
Mi ochond ial dys unc ion Complex I inhibi ion
→ elec on leakage
→ O₂•–, H₂O₂
NADH dehyd ogenase (Complex I),
mi ochond ial DNA
↑ROS, ene gy ailu e, apop osis
Dopamine oxida ion Au ooxida ion and MAO-B
ca abolism o cy osolic
dopamine
Dopamine, MAO-B, VMAT2 Quinone and H₂O₂ p oduc ion,
α- synuclein agg ega ion
I on accumula ion Fen on eac ion
(Fe²+ + H₂O₂ → •OH)
Fe²+, e i in, ans e in, e opo in Lipid pe oxida ion, p o ein oxida ion,
α- syn agg ega ion
Mic oglial ac i a ion NADPH oxidase and iNOS
→ O₂•–, NO•, ONOO–
NOX2, iNOS, TNF- α, IL-1β Neu oin lamma ion, oxida i e/
ni osa i e s ess
As ocy ic dys unc ion ↓EAAT1/2, ↓GSH syn hesis EAAT1, EAAT2, glu ama e, GCL, GS Glu ama e exci o oxici y, impai ed
neu onal edox balance
Pha macia 72: 1–12 3
al. 2014). Labile i on pa icipa es in he Fen on eac ion,
con e ing H₂O₂ in o highly eac i e hyd oxyl adicals
ha damage lipids, nucleic acids, and p o eins.
Mo eo e , i on accele a es α-synuclein agg ega ion
h ough di ec binding, acili a ing he o ma ion o ox-
ic oligome s and ib ils (U e sky e al. 2001). Thus, i on
con ibu es no only o oxida i e inju y bu also o he
p o einopa hy cha ac e is ic o PD. The homeos a ic eg-
ula ion o i on, no mally main ained by p o eins such as
e i in (s o age), ans e in ( anspo ), and e opo in
(expo ), is o en impai ed in PD. Down egula ion o e -
opo in and insu icien e i in exp ession esul in cy o-
solic i on o e load (Mo is e al. 2017).
Ta ge ing i on accumula ion has eme ged as a p omis-
ing he apeu ic s a egy. I on chela o s such as de e ip one
ha e demons a ed e icacy in educing b ain i on le els
and imp o ing mo o unc ion in bo h animal models and
ea ly-phase clinical ials (De os e al. 2014). These ind-
ings unde sco e he cen al ole o me al-induced oxida-
i e mechanisms in PD pa hogenesis and highligh hei
ele ance as d uggable a ge s.
Ta ge s o oxida i e damage
Lipid pe oxida ion ep esen s one o he ea lies and mos
de imen al mani es a ions o oxida i e s ess in Pa kin-
son’s disease (PD). The abundan p esence o polyunsa -
u a ed a y acids (PUFAs) in neu onal memb anes—
especially in dopamine gic neu ons o he subs an ia
nig a— ende s hem pa icula ly suscep ible o pe oxi-
da i e inju y. Hyd oxyl adicals (•OH), among he mos
eac i e ROS, ini ia e his p ocess by abs ac ing hyd ogen
a oms om PUFAs, igge ing chain eac ions ha com-
p omise memb ane luidi y, pe meabili y, and in eg i y
(Gaki and Papa assiliou 2014).
Among he mos s udied lipid pe oxida ion by-p od-
uc s a e malondialdehyde (MDA) and 4-hyd oxynonenal
(4-HNE), which se e bo h as bioma ke s and media o s
o cellula oxici y. These aldehydes o m co alen adduc s
wi h nucleic acids, p o eins, and memb ane lipids, he eby
al e ing hei s uc u e and unc ion (Ba e a e al. 2018).
Ele a ed concen a ions o MDA and 4-HNE ha e been
consis en ly de ec ed in he subs an ia nig a o PD pa ien s
in pos mo em analyses (Yo i aka e al. 1996; Zhou e al.
2008). No ably, 4-HNE modi ies mi ochond ial p o eins
and componen s o he espi a o y chain, impai ing ATP
syn hesis and exace ba ing ene gy ailu e. Fu he mo e, i
p omo es he agg ega ion o α-synuclein in o β-shee - ich
oligome s, hus ein o cing p o eo oxic s ess and neu o-
nal degene a ion (B een e al. 2013).
P o ein oxida ion cons i u es ano he hallma k o ox-
ida i e damage in PD and signi ican ly con ibu es o
neu onal dys unc ion. ROS-induced modi ica ions al e
he con o ma ion and ac i i y o a wide ange o p o eins,
including mi ochond ial enzymes, cy oskele al elemen s,
and an ioxidan de enses (S ad man and Le ine 2000).
These changes may lead o loss o enzyma ic ac i i y, en-
hanced deg ada ion, and impai ed cellula signaling.
O pa icula impo ance is he oxida ion o α-synucle-
in, which accele a es i s mis olding and agg ega ion in o
oxic oligome s. These agg ega es in e e e wi h synap ic
unc ion, mi ochond ial dynamics, and au ophagy–ly-
sosomal pa hways, ul ima ely o ming Lewy bodies—a
pa hological hallma k o PD (Poon e al. 2005; Shulman
e al. 2011). Mi ochond ial p o eins such as complex I a e
especially ulne able o oxida i e modi ica ion, leading
o u he dis up ion o elec on anspo and inc eased
ROS gene a ion (Schapi a e al. 1990). Inac i a ion o key
enzymes—including glu a hione pe oxidase, supe oxide
dismu ase, and ubiqui in ligases— u he ampli ies edox
imbalance and impai s p o eos asis (Bo e e al. 2018).
Nucleic acids a e also majo a ge s o oxida i e s ess.
Neu ons, due o hei high me abolic ac i i y and limi ed
egene a i e capaci y, a e pa icula ly suscep ible o oxi-
da i e DNA and RNA damage. Hyd oxyl adicals a ack
nucleobases and suga -phospha e backbones, gene a ing
s and b eaks and mu agenic lesions. One o he mos
widely ecognized bioma ke s is 8-hyd oxy-2’-deox-
yguanosine (8-OHdG), o med by oxida i e damage o
guanine esidues. Inc eased le els o 8-OHdG ha e been
obse ed in he SNpc o PD pa ien s and co ela e wi h
disease se e i y (Zhang e al. 1999).
Oxida i e damage o RNA, including mRNA, RNA,
and RNA, dis up s ansla ion ideli y and p o ein syn he-
sis. Gi en i s single-s anded s uc u e and cy osolic local-
iza ion nea ROS-gene a ing o ganelles like mi ochond ia,
RNA is pa icula ly p one o oxida ion. This esul s in he
p oduc ion o unca ed o mis olded p o eins, u he ag-
g a a ing p o eo oxic s ess (Nunomu a e al. 2006).
Mo eo e , impai ed DNA epai mechanisms exac-
e ba e oxida i e inju y. De iciencies in base excision e-
pai (BER) enzymes such as 8-oxoguanine glycosylase 1
(OGG1) ha e been epo ed in PD b ains, leading o he
pe sis ence o oxidized nucleo ides, genomic ins abili y,
and apop o ic signaling (Sande s e al. 2014).
An ioxidan de enses and hei deple-
ion in Pa kinson’s disease
In heal hy neu ons, edox homeos asis is main ained by
a sophis ica ed ne wo k o enzyma ic and non-enzyma ic
an ioxidan sys ems ha neu alize eac i e oxygen spe-
cies (ROS) and p e en damage o lipids, p o eins, and
nucleic acids. Among hese, glu a hione (GSH) se es as
he mos abundan and essen ial in acellula an ioxidan .
GSH de oxi ies ROS such as hyd ogen pe oxide (H₂O₂)
and lipid hyd ope oxides h ough enzyma ic eac ions
ca alyzed by glu a hione pe oxidase (GPx) and is egene -
a ed om i s oxidized o m (GSSG) ia glu a hione educ-
ase (GR) (Pe y e al. 1982; Seile e al. 2008).
In Pa kinson’s disease (PD), a ma ked deple ion o GSH
has been consis en ly epo ed in he subs an ia nig a pa s
compac a (SNpc), p eceding bo h he degene a ion o do-
pamine gic neu ons and he o ma ion o Lewy bodies
(Dex e e al. 1989; Sian e al. 1994). This ea ly educ ion
in GSH impai s he neu onal capaci y o de oxi y H₂O₂
Ga ip A e al.: In i o models o oxida i e s ess in neu odegene a ion4
and lipid pe oxides, he eby ampli ying oxida i e s ess
and con ibu ing o neu onal ulne abili y.
Beyond GSH, se e al an ioxidan enzymes—includ-
ing supe oxide dismu ases (SOD1 and SOD2), ca alase,
and glu a hione pe oxidase 4 (GPx4)—play c ucial oles
in main aining edox balance. Dys egula ion o hese
enzymes has been obse ed in PD b ains, cha ac e ized
by al e ed exp ession pa e ns and dec eased enzyma ic
ac i i y (Seile e al. 2008; Gaki and Papa assiliou 2014).
No ably, GPx4 is indispensable o educing phospholip-
id hyd ope oxides and inhibi ing e op osis, an i on-de-
penden o m o cell dea h inc easingly implica ed in PD
pa hology (S ockwell e al. 2017).
Fu he mo e, oxida i e s ess may dis up he an-
sc ip ional con ol o an ioxidan de ense genes. Nucle-
a ac o e y h oid 2– ela ed ac o 2 (N 2) is a mas e
egula o o an ioxidan gene exp ession, including hose
in ol ed in GSH biosyn hesis. Reduced N 2 ac i i y in
PD has been associa ed wi h impai ed up egula ion o
p o ec i e genes, u he exace ba ing oxida i e damage
(Las es-Becke e al. 2012).
Toge he , hese indings sugges ha deple ion o en-
dogenous an ioxidan s in PD is no me ely a consequence
o disease p og ession bu a p ima y pa hogenic mecha-
nism. This highligh s he an ioxidan sys em as a p omis-
ing he apeu ic a ge o coun e ac ing neu odegene a-
ion in Pa kinson’s disease.
Glial cell in ol emen in oxida i e s ess
Mic oglia, he esiden immune cells o he cen al ne -
ous sys em (CNS), play a dual ole in neu oin lamma ion
and oxida i e s ess. Unde physiological condi ions, hey
con ibu e o neu onal homeos asis h ough con inuous
en i onmen al su eillance. In Pa kinson’s disease (PD),
howe e , mic oglia become ch onically ac i a ed, adop -
ing a p o-in lamma o y M1 pheno ype cha ac e ized by
he elease o eac i e oxygen species (ROS) and p o-in-
lamma o y cy okines such as umo nec osis ac o -alpha
(TNF-α), in e leukin-1 be a (IL-1β), and in e leukin-6
(IL-6) (Block e al. 2007; Zhou e al. 2008). This pe sis en
ac i a ion gene a es a neu o oxic mic oen i onmen ha
exace ba es dopamine gic neu on degene a ion.
Ac i a ed mic oglia p oduce supe oxide adicals (O₂•–)
ia NADPH oxidase and ni ic oxide (NO) h ough he
ac ion o inducible ni ic oxide syn hase (iNOS). These e-
ac i e species can in e ac o o m pe oxyni i e (ONOO–
), a highly eac i e ni ogen species ha induces lipid
pe oxida ion, mi ochond ial dys unc ion, and p o ein
ni a ion (Gao and Hong 2008). Fu he mo e, mic oglial
ac i a ion is pe pe ua ed by eedback mechanisms in ol -
ing dange -associa ed molecula pa e ns (DAMPs), such
as ex acellula α-synuclein agg ega es eleased by degen-
e a ing neu ons (Kim e al. 2013).
As ocy es also play a key ole in main aining edox
equilib ium by supplying glu a hione (GSH) p ecu -
so s o neu ons and egula ing ex acellula glu ama e
le els ia exci a o y amino acid anspo e s (EAAT1
and EAAT2) (D ingen 2000). In PD, as ocy es exhib-
i mo phological a ophy and unc ional impai men ,
collec i ely e e ed o as as oglial dys ophy, which
comp omises hei an ioxidan capaci y and neu op o-
ec i e suppo (Boo h e al. 2017).
Mo eo e , as ocy es may unde go a pheno ypic shi
owa d a neu o oxic A1 s a e, losing neu o ophic unc-
ions and eleasing p o-in lamma o y media o s. This
ansi ion is associa ed wi h down egula ion o glu ama e
anspo e s and educed exp ession o GSH-syn hesiz-
ing enzymes, p omo ing glu ama e exci o oxici y and ox-
ida i e s ess (Liddelow e al. 2017). As such, as ocy ic
dys unc ion con ibu es o non-cell-au onomous mecha-
nisms o dopamine gic neu odegene a ion in PD.
The in e ela ed p ocesses o mi ochond ial dys unc ion,
dopamine oxida ion, i on accumula ion, and glial ac i a-
ion ha collec i ely d i e oxida i e s ess and dopamine -
gic cell dea h in Pa kinson’s disease a e illus a ed in Fig. 1.
Figu e 1. Mechanisms o oxida i e s ess–induced dopamine gic neu odegene a ion in Pa kinson’s disease.
Pha macia 72: 1–12 5
Consequences: signaling pa hways and
cell dea h
Reac i e oxygen species (ROS) a e no me ely passi e agen s
o molecula damage; hey also se e as ac i e modula o s
o in acellula signaling cascades ha culmina e in neu o-
nal dys unc ion and cell dea h. Among he mos ex ensi e-
ly s udied ROS- esponsi e pa hways in Pa kinson’s disease
(PD) is he mi ogen-ac i a ed p o ein kinase (MAPK) cas-
cade. Oxida i e s ess ac i a es ups eam kinases such as
apop osis signal- egula ing kinase 1 (ASK1), which phos-
pho yla e downs eam e ec o s like c-Jun N- e minal ki-
nase (JNK) and p38 MAPK, esul ing in p o-apop o ic gene
exp ession, mi ochond ial dys unc ion, and ac i a ion o
cell dea h pa hways (Wang e al. 2004; Choi e al. 2012).
Ano he c i ical pa hway is he nuclea ac o kappa-ligh -
chain-enhance o ac i a ed B cells (NF-κB), a ansc ip ion
ac o ha in eg a es signals om oxida i e and in lamma-
o y s imuli. In PD models, ch onic NF-κB ac i a ion leads
o ansc ip ional up egula ion o p o-in lamma o y cy o-
kines, p omo ing glial ac i a ion and con ibu ing o p o-
g essi e neu odegene a ion (Ghosh e al. 2007). In pa allel,
he umo supp esso p o ein p53 is ac i a ed by ROS and
DNA damage, o ches a ing mi ochond ial ou e mem-
b ane pe meabiliza ion (MOMP), elease o cy och ome c,
and subsequen caspase ac i a ion (Duan e al. 2002).
Beyond apop osis, e op osis has eme ged as an al e -
na i e and highly ele an o m o egula ed cell dea h in
PD. This i on-dependen p ocess is cha ac e ized by glu-
a hione deple ion, inac i a ion o glu a hione pe oxidase
4 (GPx4), and accumula ion o lipid pe oxides (Dixon e
al. 2012; Do Van e al. 2016). Mo phologically, e op osis
is dis inguished by sh unken mi ochond ia, absen ch o-
ma in condensa ion, and loss o plasma memb ane in eg-
i y. The high i on con en and abundance o polyunsa u-
a ed a y acids in subs an ia nig a pa s compac a (SNpc)
neu ons make hem pa icula ly ulne able o e op o ic
dea h (S ockwell e al. 2017).
Cumula i ely, oxida i e s ess se es as a cen al d i -
e o dopamine gic neu odegene a ion in PD h ough i s
impac on edox-sensi i e signaling pa hways and cell
dea h p og ams. ROS de i ed om dys unc ional mi o-
chond ia, dopamine me abolism, and i on o e load in lic
widesp ead damage o cellula mac omolecules—includ-
ing lipids, p o eins, and nucleic acids. This damage ig-
ge s downs eam signaling cascades such as MAPK, NF-
κB, and p53, ul ima ely esul ing in apop osis, e op osis,
and sus ained neu oin lamma ion.
Compounding his p ocess is he deple ion o endoge-
nous an ioxidan s, including glu a hione (GSH), supe oxide
dismu ase (SOD), ca alase, and GPx4, which educes he
neu onal capaci y o neu alize ROS. Addi ionally, glial dys-
unc ion—mani es ed by mic oglial ac i a ion and as ocy ic
ailu e— u he ampli ies oxida i e s ess and con ibu es o
a oxic mic oen i onmen . Thus, unde s anding he in e play
be ween ROS, signaling ne wo ks, and egula ed cell dea h
pa hways p o ides a mechanis ic ounda ion o de eloping
neu op o ec i e s a egies a ge ing oxida i e s ess in PD.
Collec i ely, oxida i e s ess ac s as bo h a igge and
an ampli ie o dopamine gic neu odegene a ion in Pa -
kinson’s disease, ini ia ing a cascade o mi ochond ial dys-
unc ion, lipid pe oxida ion, and p o ein mis olding ha
culmina es in neu onal dea h. Howe e , neu ons possess
in insic adap i e mechanisms designed o coun e ac e-
dox imbalance and o es o e cellula homeos asis. These
endogenous neu op o ec i e sys ems, encompassing bo h
enzyma ic and non-enzyma ic an ioxidan de enses, play
a decisi e ole in mi iga ing oxida i e inju y and main-
aining neu onal iabili y. Unde s anding hese de ense
pa hways p o ides essen ial insigh in o he molecula ba-
sis o neu onal esilience and o e s a ounda ion o he
de elopmen o a ge ed neu op o ec i e s a egies.
Mechanisms o neu op o ec ion
The neu onal capaci y o wi hs and oxida i e s ess elies on
an in ica ely coo dina ed hie a chy o de ense mechanisms
ha es ic he gene a ion o eac i e oxygen species (ROS),
neu alize p e-exis ing adicals, and epai oxida i ely mod-
i ied biomolecules be o e i e e sible dys unc ion occu s.
These p o ec i e sys ems unc ion wi hin bo h aqueous
and lipid compa men s and a e b oadly di ided in o en-
zyma ic and non-enzyma ic an ioxidan ne wo ks (Godic
e al. 2014). In he cen al ne ous sys em (CNS), hei
impo ance is ampli ied by he b ain’s disp opo iona ely
high oxygen consump ion, en ichmen in polyunsa u a ed
lipids, and limi ed egene a i e po en ial. Among all neu-
onal popula ions, dopamine gic neu ons o he subs an ia
nig a pa s compac a a e pa icula ly suscep ible o oxida i e
s ess due o hei ele a ed me abolic ac i i y, eliance on
mi ochond ial espi a ion, and ela i ely low an ioxidan
bu e ing capaci y. Dys egula ion o essen ial an ioxidan
enzymes—including supe oxide dismu ase (SOD), ca alase,
and glu a hione pe oxidases (GPx)—has been documen ed
in mul iple b ain egions and co ela es wi h mi ochond i-
al impai men and p og essi e neu onal loss in Pa kinson’s
disease (Miglio e and Coppedè 2009; Zhang e al. 2018).
Enzyma ic an ioxidan sys ems
Enzyma ic an ioxidan s cons i u e he i s line o de ense
agains ROS. Supe oxide dismu ases (SODs) ca alyze he dis-
mu a ion o he supe oxide anion (O₂•–) in o hyd ogen pe -
oxide (H₂O₂), he eby p e en ing i s in e ac ion wi h ni ic
oxide and subsequen o ma ion o pe oxyni i e (ONOO–).
Th ee human iso o ms a e dis inguished by me al co ac-
o s and localiza ion: Cu/Zn-SOD (SOD1) in he cy osol,
Mn-SOD (SOD2) in mi ochond ia, and ex acellula SOD
(SOD3) in he in e s i ial space (Pisoschi and Pop 2015).
Ca alase subsequen ly decomposes H₂O₂ in o wa e and mo-
lecula oxygen, p e en ing i s in ol emen in Fen on chem-
is y ha yields highly eac i e hyd oxyl adicals (•OH). Pe -
oxi edoxins and hio edoxin educ ases ac syne gis ically o
educe o ganic pe oxides and o main ain p o ein hiol ho-
meos asis, ensu ing dynamic equilib ium be ween oxida ion
and educ ion ac oss cellula compa men s.
Ga ip A e al.: In i o models o oxida i e s ess in neu odegene a ion6
The glu a hione sys em
The glu a hione (GSH) sys em ep esen s he co ne s one
o in acellula an ioxidan de ense. I encompasses e-
duced glu a hione, glu a hione educ ase (GR), glu a hi-
one pe oxidases (GPx), and glu a hione S- ans e ases
(GSTs). GR main ains he cellula pool o educed GSH
by ca alyzing he NADPH-dependen educ ion o oxi-
dized glu a hione (GSSG) (Meis e and Ande son 1983).
GPx enzymes, cha ac e ized by hei selenium-con ain-
ing ac i e si es, ca alyze he educ ion o bo h hyd ogen
and lipid hyd ope oxides. GPx1 e icien ly de oxi ies
soluble H₂O₂, whe eas GPx4 uniquely educes complex
lipid pe oxides embedded wi hin phospholipid bilaye s
(Lobo e al. 2010). GSTs con ibu e o cy op o ec ion by
conjuga ing elec ophilic xenobio ics and lipid pe oxi-
da ion p oduc s o GSH, acili a ing hei neu aliza ion
and emo al (Josephy 2010).
In Pa kinson’s disease (PD), ea ly and p o ound de-
ple ion o GSH in he subs an ia nig a (Pe y e al. 1982)
leads o a decline in GPx ac i i y, mi ochond ial ins a-
bili y, and edox disequilib ium. No ably, impai men
o GPx4 p omo es e op osis—an i on-dependen ,
lipid pe oxide–d i en cell dea h pa hway inc easing-
ly ecognized as a majo con ibu o o dopamine gic
neu odegene a ion (Seile e al. 2008). Thus, he glu a-
hione sys em no only de oxi ies eac i e in e media es
bu also de e mines he h eshold be ween neu onal
su i al and e op o ic ulne abili y.
Non-enzyma ic an ioxidan de enses
Non-enzyma ic an ioxidan s complemen enzyma ic de-
enses by di ec ly sca enging ee adicals and egene a -
ing oxidized enzyme co ac o s. Glu a hione i sel , h ough
i s cys einyl hiol g oup, ac s as a ubiqui ous in acellu-
la edox bu e . Mela onin, an amphiphilic indoleamine,
neu alizes a b oad spec um o ROS and eac i e ni o-
gen species (RNS)—including hyd oxyl adicals, supe -
oxide anions, and ni ic oxide—while up egula ing he
ansc ip ion o an ioxidan enzymes wi hin he GSH and
hio edoxin sys ems (Rei e e al. 2017). Vi amin E (α- o-
cophe ol), he p edominan lipid-soluble an ioxidan ,
localizes wi hin cellula memb anes, whe e i in e up s
lipid pe oxida ion chain eac ions by dona ing hyd ogen
a oms o lipid pe oxyl adicals. Vi amin C (asco bic acid),
a wa e -soluble an ioxidan , ac s syne gis ically by egen-
e a ing α- ocophe ol om i s oxidized o m, he eby sus-
aining memb ane p o ec ion (Bi ben e al. 2012; Pisoschi
and Pop 2015). Expe imen al and clinical s udies ha e
shown ha mela onin and i amin E exe neu op o ec-
i e e ec s in PD models by a enua ing oxida i e damage,
p ese ing dopamine gic neu ons, and enhancing en-
dogenous an ioxidan ac i i y (Shoulson 1998; González-
González e al. 2018). Collec i ely, hese small-molecule
an ioxidan s se e as a seconda y, apid- esponse sys em
ha complemen s enzyma ic de oxi ica ion p ocesses and
main ains edox homeos asis unde s ess condi ions.
Inhibi ion and de oxi ica ion o lipid
pe oxida ion
Supp ession o lipid pe oxida ion cons i u es a pi o al neu o-
p o ec i e mechanism agains oxida i e s ess–induced neu-
onal damage. Polyunsa u a ed a y acids (PUFAs), highly
abundan in neu onal memb anes, a e p one o adical-me-
dia ed pe oxida ion, yielding cy o oxic aldehydes such as
4-hyd oxynonenal (4-HNE) and malondialdehyde (MDA).
These eac i e by-p oduc s p opaga e oxida i e damage and
co alen ly modi y p o eins, lipids, and nucleic acids, he eby
p omo ing α-synuclein agg ega ion and mi ochond ial dys-
unc ion (Yo i aka e al. 1996; Niki e al. 2005).
Pha macological inhibi ion o lipoxygenase (LOX)
enzymes, pa icula ly 5-LOX, mi iga es enzyma ic lipid
hyd ope oxide o ma ion. The clinically app o ed 5-LOX
inhibi o zileu on unc ions by dis up ing i on coo dina-
ion wi hin he enzyme’s ca aly ic cen e , he eby cu ail-
ing lipid pe oxide syn hesis. Mo e ecen ly, supplemen a-
ion wi h deu e a ed PUFAs has eme ged as an inno a i e
s a egy. The subs i u ion o bis-allylic hyd ogen a oms
wi h deu e ium s eng hens he C–D bond, slowing ad-
ical-media ed hyd ogen abs ac ion and consequen ly in-
hibi ing bo h enzyma ic and non-enzyma ic lipid pe oxi-
da ion (Gaschle and S ockwell 2017).
Glu a hione pe oxidase 4 (GPx4) emains indispensable
o de oxi ying p e- o med lipid hyd ope oxides, including
hyd ope oxyeicosa e aenoic and hyd ope oxyoc adecadi-
enoic acids. The enzyme’s selenocys eine esidue ca alyzes
nucleophilic a ack on he pe oxide oxygen, o ming a an-
sien selenic acid in e media e ha is subsequen ly educed
by GSH. This ca aly ic cycle egene a es he ac i e enzyme
and oxidizes GSH o GSSG, comple ing a c i ical an ioxi-
dan loop ha main ains neu onal memb ane s abili y.
The dynamic in e play be ween oxida i e inju y and an-
ioxidan de ense ul ima ely dic a es dopamine gic neu on
su i al unde me abolic and edox s ess. When he en-
zyma ic and non-enzyma ic de ense sys ems al e , edox
homeos asis collapses owa d oxida i e disequilib ium, p e-
cipi a ing lipid pe oxida ion, e op osis, and neu odegen-
e a ion. Deciphe ing he molecula c oss alk among hese
p o ec i e pa hways has g ea ly e ined ou unde s anding o
neu onal ulne abili y and esilience in Pa kinson’s disease.
Ne e heless, ansla ing hese mechanis ic insigh s
in o ac ionable neu op o ec i e s a egies demands expe -
imen al pla o ms ha accu a ely ecapi ula e he oxida-
i e mic oen i onmen o he human b ain. In i o neu-
onal models—spanning immo alized neu oblas oma
lines, p ima y neu onal cul u es, and s em cell–de i ed
dopamine gic sys ems—p o ide con ollable, ep oduc-
ible amewo ks o dissec ing edox- egula ed signaling,
sc eening an ioxidan compounds, and modeling oxida-
i e neu o oxici y. These sys ems b idge he concep ual
gap be ween molecula edox biology and ansla ional
he apeu ics, o ming he expe imen al ounda ion o he
nex s age o esea ch: he de elopmen and alida ion o
in i o models o s udying oxida i e s ess–d i en neu-
onal inju y and p o ec ion.
Pha macia 72: 1–12 7
In i o models o s udying
neu onal oxici y
To expe imen ally alida e he molecula mechanisms
o oxida i e s ess and neu op o ec ion desc ibed abo e,
eliable in i o sys ems a e indispensable. These models
enable mechanis ic explo a ion o dopamine gic ulne -
abili y, allow o quan i a i e e alua ion o an ioxidan
in e en ions, and p o ide a high- esolu ion pla o m o
sc eening neu op o ec i e agen s. In con as o complex
in i o en i onmen s, in i o app oaches o e p ecise
con ol o e expe imen al condi ions, enhanced ep o-
ducibili y, and di ec manipula ion o edox pa ame e s a
he cellula and subcellula le els (F eshney 2001).
Such sys ems ha e become he co ne s one o con-
empo a y neu odegene a ion esea ch, pa icula ly
o elucida ing he oxida i e mechanisms ha unde lie
Pa kinson’s disease (PD).
P inciples and a ionale o in i o
modeling o Pa kinson’s disease
E ec i e in i o modeling o PD equi es mimicking he
dis inc i e ea u es o dopamine gic neu ons om he
subs an ia nig a pa s compac a (SNpc)—cells ha a e
uniquely suscep ible o oxida i e s ess due o hei high
me abolic ac i i y, dopamine au o-oxida ion, and abun-
dan mi ochond ial con en . Dopamine me abolism i sel
gene a es hyd ogen pe oxide (H₂O₂), supe oxide (O₂•–),
and dopamine quinones, he eby ein o cing a p o-oxi-
dan in acellula milieu. Consequen ly, app op ia e cell
models mus p ese e he me abolic, enzyma ic, and sig-
naling cha ac e is ics o dopamine gic neu ons, including
exp ession o y osine hyd oxylase (TH), he dopamine
anspo e (DAT), and esicula monoamine anspo e
2 (VMAT2), as well as unc ional mi ochond ial espi a-
ion (Lopes e al. 2017).
In i o modeling p o ides unique oppo uni ies o dis-
sec he cascade o oxida i e inju y— om ROS o ma ion
and lipid pe oxida ion o mi ochond ial dys unc ion and
cell dea h. These sys ems also acili a e mechanis ic s udies
o p o ec i e agen s such as polyphenols, ca eine de i a i es,
and syn he ic an ioxidan s unde igh ly egula ed oxida i e
en i onmen s. By in eg a ing pha macological and bio-
chemical endpoin s, in i o s udies b idge he gap be ween
molecula hypo hesis and ansla ional neu op o ec ion.
Neu o oxin-based in i o models
o oxida i e s ess
The mos widely used models o PD- ela ed oxida i e s ess
a e hose employing speci ic dopamine gic neu o oxins,
including 6-hyd oxydopamine (6-OHDA) and 1-me h-
yl-4-phenylpy idinium (MPP+). These compounds selec-
i ely a ge ca echolamine gic neu ons and ep oduce
essen ial hallma ks o PD, such as mi ochond ial dys unc-
ion, ROS o e p oduc ion, and apop o ic cell dea h.
6-OHDA is a syn he ic ca echolamine ha is selec i ely
aken up by dopamine gic and no ad ene gic neu ons ia
DAT and NAT anspo e s. Once in e nalized, i unde goes
enzyma ic (MAO-A) and au o-oxida ion, p oducing hyd o-
gen pe oxide, supe oxide adicals, and eac i e quinones
(Simola e al. 2007). These quinones co alen ly modi y cys-
eine esidues on cellula p o eins, leading o enzyme inac-
i a ion and oxida i e damage. Mo eo e , 6-OHDA oxida-
ion yields neu omelanin-like pigmen s, whose ex acellula
elease upon neu onal dea h ac i a es mic oglia and ini i-
a es seconda y neu oin lamma ion (Va ešlija e al. 2020).
In i o, 6-OHDA is p ima ily applied o SH-SY5Y,
PC12, and p ima y mesencephalic cul u es. I s ad an ag-
es include high selec i i y o ca echolamine gic neu ons
and ep oducible dose-dependen oxici y, allowing o
consis en assessmen o an ioxidan and neu op o ec-
i e compounds. Howe e , a excessi e concen a ions,
6-OHDA induces non-speci ic cy o oxici y due o o e -
whelming ROS o ma ion. Despi e his limi a ion, i e-
mains an in aluable model o in es iga ing oxida i e
s ess–induced mi ochond ial dys unc ion, glu a hione
deple ion, and apop o ic signaling (Blum e al. 2001).
The neu o oxin MPTP and i s me aboli e MPP+ ep e-
sen ano he classical sys em o ep oducing dopamine -
gic neu odegene a ion in i o. Following me abolic con-
e sion by glial monoamine oxidase B (MAO-B), MPP+
is selec i ely anspo ed in o dopamine gic neu ons
h ough he dopamine anspo e (DAT). Wi hin mi o-
chond ia, i inhibi s complex I
(NADH:ubiquinone oxido educ ase), esul ing in ATP
deple ion, ROS gene a ion, and ac i a ion o apop o ic
cascades in ol ing p38 MAPK and JNK pa hways (Gao e
al. 2003). MPP+ oxici y has been ex ensi ely cha ac e ized
in SH-SY5Y, LUHMES, and iPSC-de i ed dopamine gic
neu ons, o e ing high ep oducibili y and mechanis ic
ele ance. While i ai h ully ecapi ula es mi ochond ial
oxida i e damage, i does no ep oduce α-synuclein ag-
g ega ion o Lewy body o ma ion. The e o e, i is mos
e ec i e o dissec ing edox imbalance, mi ochond ial
pe meabili y ansi ion, and e op o ic pa hways unde
con olled oxida i e condi ions (Kalkman and Loe sche
2003; Zeng e al. 2006).
Cellula sys ems o modeling
dopamine gic neu odegene a ion
The choice o cellula model is c i ical o ensu ing biolog-
ical ele ance, ep oducibili y, and ansla ional alue. Be-
low a e he mos widely used sys ems, ca ego ized by o igin,
pheno ype, and applicabili y o oxida i e s ess esea ch.
SH-SY5Y Cells
De i ed om human neu oblas oma, SH-SY5Y cells
exhibi ca echolamine gic p ope ies and exp ess y o-
Ga ip A e al.: In i o models o oxida i e s ess in neu odegene a ion8
sine hyd oxylase (TH) and dopamine-β-hyd oxylase.
These cells can be di e en ia ed in o neu on-like phe-
no ypes using e inoic acid, b ain-de i ed neu o ophic
ac o (BDNF), o pho bol es e s, which enhance dopa-
mine gic ma ke s such as DAT and VMAT2 (Agholme
e al. 2010). They a e a mains ay o in i o PD esea ch
owing o hei human o igin, cos -e ec i eness, and
ease o gene ic and pha macological manipula ion.
Thei limi a ions include a umo -de i ed geno ype,
limi ed ma u a ion, and g adual loss o dopamine gic
ai s a high passage numbe s. Ne e heless, hey e-
main ideal o oxida i e s ess assays, neu op o ec ion
sc eening, and mechanis ic s udies on mi ochond ial
dys unc ion and apop osis.
LUHMES Cells
LUHMES (Lund human mesencephalic) cells o igina e
om he human emb yonic mesencephalon and ep e-
sen an ad anced model o pos -mi o ic dopamine gic
neu ons. Upon di e en ia ion wi h e acycline, cAMP,
and GDNF, hey exp ess a comple e dopamine gic p o ile
(TH, DAT, VMAT2, and D2 ecep o s) and exhibi spon-
aneous elec ical ac i i y (Zhang e al. 2014).
Thei homogenei y, s able pheno ype, and human o -
igin make hem supe io o immo alized lines o long-
e m and mechanis ic oxici y s udies. They a e pa icu-
la ly sui able o MPP+ and 6-OHDA models, as well as
siRNA-media ed modula ion o edox enzymes. The main
challenge is hei s ic di e en ia ion equi emen and
highe sensi i i y o oxida i e s ess, necessi a ing me icu-
lous cul u e condi ions.
PC12 Cells
PC12 cells, de i ed om a pheoch omocy oma, p o ide
a obus sys em o s udying neu i e ou g ow h, neu o o-
phin signaling, and oxida i e s ess esponses (Malage-
lada and G eene 2008). They syn hesize dopamine and
no epineph ine bu lack dopamine anspo e s (DAT),
which limi s hei suscep ibili y o 6-OHDA and MPP+.
Thei me abolism elies hea ily on glycolysis, esul ing
in educed sensi i i y o mi ochond ial inhibi o s. None-
heless, hey emain highly aluable o e alua ing neu-
o ophic p o ec ion, NGF-induced di e en ia ion, and
an ioxidan esponse pa hways.
P ima y dopamine gic cul u es
P ima y midb ain dopamine gic neu ons isola ed om
oden emb yos mos closely eplica e he na i e neu o-
nal mic oen i onmen . They exhibi au hen ic mo phol-
ogy, exp ession o TH, DAT, and VMAT2, and main ain
neu on–glia in e ac ions ha in luence oxida i e homeo-
s asis. These cul u es a e ins umen al o s udying neu-
oin lamma ion, mic oglial ac i a ion, and he in e play
be ween neu onal and glial oxida i e mechanisms (Kalk-
man and Loe sche 2003).
Howe e , e hical limi a ions, a iabili y among
p epa a ions, and in e species di e ences in edox
egula ion es ic hei widesp ead use. Despi e his,
hey p o ide unpa alleled physiological ideli y and
se e as a c i ical e e ence o alida ing indings om
immo alized lines.
iPSC-de i ed dopamine gic neu ons
Induced plu ipo en s em cells (iPSCs), ep og ammed
om adul soma ic cells h ough exp ession o Oc 4,
Sox2, Kl 4, and c-Myc, ep esen he mos ad anced hu-
man-based in i o model. When di e en ia ed in o dopa-
mine gic neu ons, hey ecapi ula e human-speci ic an-
sc ip ional and me abolic ea u es, exp essing TH, DAT,
and α-synuclein (Soldne e al. 2009). iPSC-de i ed neu-
ons p o ide an unp eceden ed oppo uni y o model bo h
spo adic and amilial PD, examine pa ien -speci ic oxida-
i e suscep ibili ies, and e alua e a ge ed an ioxidan he -
apies. Limi a ions include labo -in ensi e p o ocols, high
cos , and ba ch- o-ba ch a iabili y in di e en ia ion e i-
ciency. Ne e heless, hey cons i u e a i al ool o p eci-
sion medicine and pe sonalized neu op o ec ion esea ch.
Synap osomes
Synap osomes—isola ed synap ic e minals de i ed
om oden o human b ain issue—o e a me aboli-
cally ac i e p epa a ion en iched in mi ochond ia and
neu o ansmi e machine y. They a e ideal o s udy-
ing p esynap ic e en s such as dopamine up ake, esic-
ula s o age, and calcium-dependen neu o ansmi e
elease (Jhou and Tai 2017).
While hey lack nuclea and pos synap ic elemen s,
hei simplici y enables high- esolu ion analysis o oxida-
i e s ess a he synap ic le el, as well as pha macologi-
cal es ing o an ioxidan and anspo e - a ge ed com-
pounds. Synap osomes a e pa icula ly aluable when
human b ain ma e ial is a ailable, b idging he ansla-
ional gap be ween cell cul u es and human pa hology.
A compa a i e o e iew o commonly employed mod-
els is p esen ed in Table 2, summa izing hei o igin, ma-
jo ea u es, and expe imen al applicabili y.
The di e si y o in i o sys ems e lec s he complex-
i y o oxida i e s ess in PD and p o ides complemen-
a y insigh s a molecula , cellula , and synap ic le els.
Each model cap u es a dis inc dimension o dopami-
ne gic ulne abili y— om mi ochond ial dys unc ion
in SH-SY5Y cells o edox egula ion in LUHMES and
synap osomal p epa a ions.
Fa om being o e simpli ied ep esen a ions o he
b ain, hese sys ems se e as p ecise analy ical ools o
dissec ing edox-dependen signaling, e alua ing an-
ioxidan e iciency, and elucida ing neu op o ec i e
Pha macia 72: 1–12 9
mechanisms. Collec i ely, hey o m he expe imen al
ounda ion o ad ancing ansla ional s a egies ha a -
ge oxida i e s ess in Pa kinson’s disease.
Conclusion
In i o models cons i u e indispensable pla o ms o de-
ciphe ing he cellula and molecula mechanisms unde -
lying Pa kinson’s disease. By enabling p ecise con ol o e
he ex acellula milieu and in acellula edox balance,
hese sys ems allow o high- esolu ion analysis o do-
pamine gic neu on biology, oxida i e inju y, and neu o-
p o ec i e signaling. Each expe imen al model— anging
om immo alized cell lines such as SH-SY5Y and PC12
o ad anced human-based sys ems like LUHMES and iP-
SC-de i ed neu ons—p o ides complemen a y insigh s
in o he mul i ace ed na u e o neu odegene a ion.
Toxin-based pa adigms employing 6-hyd oxydo-
pamine (6-OHDA) and 1-me hyl-4-phenylpy idini-
um (MPP+) emain undamen al o ecapi ula ing key
pa hogenic p ocesses, including mi ochond ial impai -
men , glu a hione deple ion, and ROS-d i en apop osis.
Meanwhile, iPSC-de i ed dopamine gic neu ons b idge
he ansla ional gap by cap u ing pa ien -speci ic ge-
ne ic and me abolic suscep ibili ies, he eby acili a ing
indi idualized d ug disco e y and edox-modula o y e-
sea ch. Al hough no single model can ep oduce he ull
pa hophysiological spec um o PD, he s a egic combi-
na ion o mul iple in i o sys ems subs an ially enhances
expe imen al ideli y and ansla ional ele ance.
Fu u e ad ancemen s will depend on he e inemen
o di e en ia ion p o ocols, he inco po a ion o glia–
neu on co-cul u e sys ems, and he de elopmen o
h ee-dimensional and o ganoid pla o ms ha mo e
accu a ely emula e he cy oa chi ec u e and oxida i e
mic oen i onmen o he human midb ain. In eg a ion
o such complex models wi h high- h oughpu sc een-
ing and omics-based analy ics will u he s eng hen
he p edic i e alue o p eclinical in es iga ions. Ul i-
ma ely, he e olu ion o in i o modeling s ands as a
c i ical b idge be ween mechanis ic neu oscience and
he apeu ic inno a ion, accele a ing he disco e y o
e ec i e in e en ions o Pa kinson’s disease.
Addi ional in o ma ion
Con lic o in e es
The au ho s ha e decla ed ha no compe ing in e es s exis .
E hical s a emen s
The au ho s decla ed ha no clinical ials we e used in he p es-
en s udy.
The au ho s decla ed ha no expe imen s on humans o hu-
man issues we e pe o med o he p esen s udy.
The au ho s decla ed ha no in o med consen was ob ained
om he humans, dono s o dono s’ ep esen a i es pa icipa -
ing in he s udy.
The au ho s decla ed ha no expe imen s on animals we e
pe o med o he p esen s udy.
The au ho s decla ed ha no comme cially a ailable immo -
alised human and animal cell lines we e used in he p esen s udy.
Use o AI
No use o AI was epo ed.
Funding
This s udy was inanced by he Eu opean Union—Nex Gene -
a ionEU h ough he Na ional Reco e y and Resilience Plan o
he Republic o Bulga ia, p ojec No. BG-RRP-2.004-0004-C01.
Au ho con ibu ions
In i o models o oxida i e s ess in neu odegene a ion
Da a a ailabili y
All o he da a ha suppo he indings o his s udy a e a ailable
in he main ex .
Table 2. Summa y o widely used in i o models o Pa kinson’s disease esea ch, including hei o igin, main ea u es, and appli-
ca ion domains.
Model O igin Ad an ages Limi a ions Applica ion in PD
1. SH-SY5Y Human neu oblas oma Easy o cul u e, widely used,
can be di e en ia ed
Pheno ype loss o e ime,
umo o igin
Tes ing an ioxidan s, 6-
OHDA and MPP+ oxici y
2. LUHMES Human emb yonic
mesencephalon
Homogeneo us popula ion,
s able dopamine gic ma ke s
Requi es complex
di e en ia ion, oxin- sensi i e
Gene ic manipula ion,
ch onic oxici y s udies
3. PC12 Ra pheoch omocy oma Robus , sui able o
neu o ophin assays
Lacks DAT, low
mi ochond ial sensi i i y
Neu o ophin- induced
di e en ia ion s udies
4. P ima y dopamine gic
cul u es
Emb yonic oden
(midb ain)
High physiologica l
ele ance, glial in e ac ion
Va iabili y, e hical
conside a ions
Neu oin lamma ion,
mi ochond ial dys unc ion
5. O gano ypic b ain slices Neona al oden s
(in si u b ain)
3D a chi ec u e, unc ional
connec i i y
Sho in i o iabili y,
echnically demanding
Connec i i y be wen b ain
egions
6. iPSC-de i ed neu ons Rep og ammed om
pa ien soma ic cells
Human o igin, models
amilial mu a ions
Expensi e, di e en ia ion
a iabili y
Modeling α- synuclein,
mi ochond ia, sc eening
7. Synap osoms Human b ain issue
(pos mo em)
Use ul o s udying
p esynap ic unc ion
Lacks comple e neu onal
a chi ec u e
P esynap ic ac i i y,
anspo e s and ecep o s
