Evaluation the effects of experimental - PowerPoint Presentation

Slide1

Evaluation the effects of experimental PCB toxication on oxidant and antioxidant status in central nervous systems tissues and the protective effect of curcumin

Assist. Prof. Dr. H Okan DOĞAN

University

of Cumhuriyet

SİVAS, TURKEY

Slide2

Polychlorinated Biphenyls

Polychlorinated Biphenyls (PCBs) are synthetically produced toxic compounds containing chlorinated hydrocarbons.Even though their manufacture has declined drastically since the 1970s. PCBs are still widely in use.One estimate (2006) suggested that 1 million tons of PCBs had been produced. 40% of this material was thought to remain in use.

Slide3

Because of their;Resistance to degradation in the environmentTheir concentration in the food chain and their persistence in the human body,They present an increasing problem as a contaminant and raise questions as to possible effects on the public health.

Slide4

Health problems associated with PCBs

PCBs associated with;Neurobehavioral and immunological changes in childrenAcne-like skin conditions in adults  Thyroid dysfunction etc.

Slide5

Mechanism of PCBs Toxicity

PCBs are metabolized by the microsomal monooxygenase system catalyzed by cytochrome P-450 to phenols.Phenols hydroxylated to cathecol and this molecule covalently bind to nucleophilic cellular macromolecules (protein, DNA and RNA) and induce DNA strand breaks and DNA repair.It has also been hypothesized that several oxidative stress caused by reactive oxygen species (ROS) could contribute to the toxicity of PCBs.

Slide6

Oxidative stress can be determined by measuring the concentrations of total antioxidant capacity. Total oxidant status (TOS) and total antioxidant status (TAS) tests are often used to estimate the overall antioxidant status.

How can

we

determine

the

change

of

oxidative

status

?

Slide7

Can we determine the damage on central nervous system by using biomarkers ?

Neuron

specific

enolase

(NSE) is

found

in

neuronal

and

neuroendocrine

tissues

.

Due to this organ-specificity, concentrations of NSE in serum

are

often elevated in diseases which result in

neuronal destruction.

Measurement

of NSE in serum

can

be

used

as a

biomarker

in

the

definition

of a variety of neuron-destructive and neurodegenerative disorders.

Slide8

Curcumin (Curcuma Longa), an extract of the rhizome turmeric, has been used for centuries in the diets and traditional medicines. The administration of curcumin has been shown to be effective in the treatment of neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease, stroke and tardive dyskinesia, as well as other brain disorders such as multiple sclerosis, depression, and brain tumours. To date, there is not any study on the effects of curcumin in PCB intoxication.

Curcumin

Slide9

Divriği Great Mosque and Hospital (1228-1229), SİVAS, TURKEY

UNESCO's

World Heritage List in 1985.

Slide10

Why we done this study?

This study aims

to

;

I

nvestigate

the

changes

on

oxidant

and

antioxidant

status

in

the

different

tissues

of

central

nervous

system

of

pups

exposed

to

PCB

mixture

(

Araclor

1254) in

the

prenatal

period

.

Determine

t

he

effects of curcumin on

oxidant

status

changes

in PCB

intoxication

Determine

the

usability

of NSE as a

biomarker

for

showing

CNS

damage

caused

by

PCBs

toxication

Slide11

Animals and the Experimental Model

The study was carried out on pregnant rats with the approval by Local Ethical Board, Ankara

University

(

Registration

number

:

2014-15-84 and dated

07/16/2014

).

In

the study, three groups

consisting

of two experimental groups and one control group were established.

In

each group, 2 females and 1 male

Wistar

rats

mated

to obtain offspring.

After

mating, each female gave birth to an average of 6 puppies in all groups.

Ten

pups were randomly selected regardless of the sex in all groups.

Any

changes were examined

during

the critical

period

for

neurologic

development

(starting with the second week of pregnancy and ongoing until 21st postnatal day) in the neurological development of these pups.

Slide12

Group I. We added only PCB mixture (Aroclor 1254) to pregnanat rats feeds’ (at a dose of 1 mg / kg / body weight for every day from 7th to 21st days of pregnancy)Group II. We added We added PCB mixture (Aroclor 1254) to pregnanat rats feeds’ (at a dose of 1 mg / kg / body weight for every day from 7th to 21st days of pregnancy) Curcumin (at a dose of 200 mg/kg/body weight dissolving in 50% DMSO solution during first 3 postnatal days) was administered orally to the neonatal pups until postnatal 21th day.Group III. Control group

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End of the Experiment

Pups in all groups were

anesthesized

with 15 mg / kg of

xylazine

and 90 mg / kg of ketamine hydrochloride using intramuscular injection

.

Blood

samples

w

ere

collected from all pups after

anesthesized

.

After

sampling

,

sodium pentobarbital was administered

intraperitoneally

to all animals at 10 mg/100 g/body

weight

then

c

ervical

dislocation was performed.

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TAS and TOS Detection

Tissue homogenizedes were prepared using tissue parts belong to cerebrum, cerebellum, pons and medulla oblangata. Tissues were homogenized for 6-10 seconds at +4 oC in a Tris buffer containing 10 mg of MgCl2 (pH:7.0, 50 mM) using a homogenizer. A colorimetric commercial kits were used (Rel Assay Diagnostics, Gaziantep, Turkey) to measure total antioxidant status (TAS) and total oxidant status (TOS).

Slide15

Determination of NSE concentrations

The quantitative sandwich ELISA technique was used for the determination of serum NSE (Sunred, Shangai, China) and analysis were performed by using auto ELISA analyzer (Chemwell ELISA)

Slide16

Statistical Analysis of the Biochemical Data

The

data normal

ity

was

tested with histogram, q-q graphs and the Shapiro-Wilk test.

Variance

homogeneity was tested with the

Levene

test.

Assumption

of

sphericity

was

analyzed

using

Mauchly’s

test.

The

analysis of TAS and TOS in types of tissues and groups was conducted using two-way analysis of variance (ANOVA) and the Greenhouse-

Geisser

test in repeated measurements.

One-way

ANOVA was used in comparing the NSE variable among the groups.

The

Bonferroni

and

Tamhane

T

2

tests were used in multivariate comparisons. The data was

analyzed

using the R 3.2.0 (

www.r-project.org

) software. p<0.05 level was accepted as significant.

Slide17

Gökpınar lake, Sivas, Turkey

Slide18

RESULTS AND DISCUSSIONS

Results and Discussion-1; When we looked cerebrum; TOS concentrations were found higher in group 1 and 2 compared to group 3 (control) The highest concentrations of TOS were found in cerebrum in group 1.

Slide19

Different experimental studies reported that the increased oxidative stress due to PCB toxications in brain (Venkataraman et al. 2009 and Venkataraman et al. 2008, Selvakumar et al. 2012)

Our results in accordance with the aforementioned studies. We think that In case of PCB toxication brain tissues are the most affected CNS tissues in terms of oxidative stress.

The

reason

for

the

presence of

higher

TOS

concentrations

in

brain

could

be

the

effects

of

metals

(

iron

, zinc, copper and manganese

)

and

high concentration of polyunsaturated fatty acids

found

in

brain

Slide20

Results

and Discussion-2

We

think that in addition to cerebrum cerebellum is other affected area from oxidative stress caused by PCB intoxication

When we looked cerebellum; TOS concentrations were found higher in group 1 and 2 compared to group 3 (control)

The pathological changes in the cerebellum has been reported by several clinical and experimental studies (Bavithra et al., Venkataraman et al.. 2008, Venkataraman et al. 2007). Our findings are in accordance with these studies.

We

believed

that

the

pathological

changes

seen

in

cerebellum

might

be

related

to

oxidative

stress

as in

the

braib

Slide21

Results

and Discussion-3

We

found

higher concentrations of TOS in group 1 and 2 compared to group 3 in pons but the power of p value was so weak We dit not find any change in terms of TOS concentrations between groups in medulla oblangata.

We

concluded

that

there

was

no

significant

effect

of

oxidative

stress

caused

by

PCB

toxication

in

Pons

and

Medlulla

oblangata

in prenatal

period

Slide22

Results and Discussion 4

SO INTERESTING

Our

hypothesis

: The

increase

of the concentrations of TAS may be related to curcumin and different antioxidant compensatory systems found in the brain. Because of TOS concentrations were higher in cerebrum than the other tissues anti oxidant compensatory systems might much more contribute on the increasing concentrations of TAS than the other tissues.

Unexpectedly, the concentrations of TAS were found higher in Group 1 than group 2 (given curcumin)

Slide23

TAS

concentrations

were

found higher in group 2 compared to group 1 in cerebellums as expected.

W

e

think

that

curcumin

might

helpful

to

increase

the

TAS

concnentration

in

cerebrum

and

cerebellum

but

when

we

take

into

consideration

the

TOS

concentration

found

in

cerebrum

and

cerebellum

we

concluded

that

the

increase

in TAS

concentrations

did

not

prevent

the

oxidative

stress

in

cerebellum

.

Slide24

Results and Discussion 5

The NSE concentration were found higher in group 1 compared to other groupsWe did not find any difference between group 2 and group 1

Bozkurt

et al. (2010) reported in their study that NSE levels increase in

toxication

with

chlorpyrifos

, an organic phosphorous compound, and NSE may be used as a bio-indicator in such events. However, different

finding

may also be found regarding the change in NSE levels in

neurotoxicosis

(

Züngün

et al., 2013). Considering the data obtained in our study, it is believed that NSE may be used as a bio-indicator in revealing central nervous system damages that can occur in PCB

toxications

.

Slide25

Thank you

Mail

adress

:

halefokan@gmail.com

hodogan@cumhuriyet.edu.tr