Based on that fact, we carry out the theme “Study the change of some oxidation indexes of people occupationally exposing to inorganic lead, the protective effects of biomass Panax vietna
Trang 1IN THESIS
1 ADN Acid desoxyribonucleic
2 ALA Acid aminolevulinic
3 ALAD Acid aminolevulinic dehydratase
4 ALT Alanin transaminase
5 AST Aspartat transaminase
6 GGT Gamma glutamyl transferase
7 GPx Glutathion peroxidase
8 GR Glutathion reductase
10 LOO• Gốc peroxyl
11 LPO Lipid hydroperoxides
12 MCH Mean corpuscular volume
13 MCHC Mean corpuscular hemoglobin concenrtration
14 MDA Malonyl dialdehyd
15 ppm Parts per million
17 ROS Reactive oxygen species
18 TAS Total antioxydant status
Trang 2When infiltrating into body, lead causes a number ofdiversified and complicated injuries on most organs andorganizations The mechanism of causing diseases of lead isinhibiting and linking with enzymes, biological substances containing-SH group but not satisfactorily explaining the systematically lead-induced injuries Some studies shown that lead entering into the bodycan stimulate the generation of free radicals and reduce the function
of the system against free radicals To clarify this matter, it isnecessary to evaluate changes of antioxidant enzymes in the body
Panax vietnamensis biomass is believed to have capacity of
preventing oxidation, protecting the body from oxidative stress Theapplication and assessment of the protection effectiveness of Panax
vietnamensis biomass for objects exposing to lead is a new issue
which has not been studied in reality Based on that fact, we carry out
the theme “Study the change of some oxidation indexes of people occupationally exposing to inorganic lead, the protective effects
of biomass Panax vietnamensis on experimental animals”
1 Objectives:
- Specify the change of some antioxidant indexes and bloodbiochemistry of people occupationally exposing to inorganic lead andexperimental animals
- Assess the protective effects of Panax vietnamensisbiomass on animals infected semi-chronic with lead acetate
2 Necessity:
Lead is an irreplaceable raw material in many industries Thenumber of people exposing to lead not only reduces but also tends toincrease despite the fact that lead triggers to several adverse effects
on human’s health When entering into the body, lead can causeoccupational exposure and oxidative stress
Nowadays, specific treatment drugs are used to treat leadpoisoning but their effects are not as expected especially in chronicpoisoning Panax vietnamensis biomass is a preparation having
Trang 3antioxidant and protective effects on the body It can reduce harms of leadcausing to the body From this fact, we conducted to study this theme.
3 New contributions of the thesis:
Lead is harmful to the body, causing oxidative stress whichleads to the alteration of antioxidant indexes The thesis studied quitecomprehensively the antioxidant indexes of workers directlyexposing to inorganic lead and on experimental animals
The thesis assessed the protective effects of Panax vietnamensisbiomass on animals semichronic poisoned with lead acetate
By dint of the research results, factories, enterprises usinglead in production enhance measures to protect heath of labors aswell as study more to choose Panax vietnamensis biomass to protectworkers occupationally exposing to lead
4 Arrangement of the thesis:
The thesis includes 137 pages consisting of 2 pages ofintroduction, 38 pages of general view, 20 pages of research objectsand methods, 41 pages of research results, 33 pages of discussion, 2pages of conclusion, 1 page of recommendation
The thesis has 37 tables, 21 charts, 5 diagrams, and 161references in which 27 in Vietnamese and 137 in English
CHAPTER 1 - GENERAL VIEW 1.1 Free radicals and system against the free radicals of the body
1.1.1 Definition of free radicals and types of Reactive Oxygen Species (ROS)
Free radicals are atoms or group of atoms whose outer layercontains unpaired electrons (single electrons) Free radicals arefrequently unstable in both energy and kinematics and tend to reach
to very short stability and longevity, strong reactivity
ROS are free radicals, active ions, and molecules containingoxygen atoms and are capable of generating free radicals or activated
by free radicals
1.1.2 Oxidative stress
Trang 4Oxidative stress is an imbalance between the formation ofreactive oxygen species and the antioxidant systems Oxidative stressmay be resulted from the decline of the antioxidant system,increasing formation of reactive oxygen species and the lack ofability to repair injuries caused by oxidation in the body
1.1.3 The formation process of free radicals.
The free radicals in the body is created from cellularrespiration chain, radioactive agents, inflammatory syndrome, thephenomenon of ischemia - reperfusion, xenobiotic agents and someother factors Xenobiotic substances including lead when enteringinto the body will be converted and xenobiotic structure significantlyaltered, they can add more -OH,-NH2,-SH,-COOH groups to formwater-soluble substances and continue connecting with substances,excreting from the body; at the same time generating ROS such as
•
2
O , 1O2, etc which have high toxicity causing oxidative stress Theantioxidants in the body such as SOD, catalase, protein SH groups,ceruloplasmin, etc in erythrocytes and liver are very sensitive to thexenobiotic
1.1.4 Antioxidant system in the body.
1.1.4.1 Ezymatic antioxidant system.
- Superoxid dismutase (SOD, EC 1.15.1.1) is an
antioxidant enzyme containing metal of oxidoreductase type and itcatalyzes the reaction to convert superoxid to O2 and H2O2:
2O•2 + 2H+ →SOD H2O2 + O2
The higher activity SOD has, the less activity O2• has SOD SOD
is an very basic antioxidant that lowers the concentration of precursor O•2
from which all other reactive oxygen species are produced
- Catalase (CAT, EC 1.15.1.1) is an enzyme catalyxing the
reaction of H2O2 decompostion
H2O2 Catalase → H2O + ½ O2
Trang 5- Peroxidase (EC 1.11.1.7) is a group of enzyems catalyzing
redox reaction belong to oxidoreductase catalyzing the following reaction
AH2 + H2O2 peroxidase → A + 2H2O
- Glutathion peroxidase (GPx) (E C.1.11.1.9) is an enzyme
catalyzing reactions to remove peroxides which activate in the tissues
and erythrocyte when the concentration of H2O2 is low.
GPx
ROOH + 2GSH GSSG + ROH + H2O
1.1.4.2 Non-enzymatic antioxidant system
It consists of three main groups: group of polyphenols, ironand copper ligands and thiols The gruops can exist both inside andoutside cells This system support for te enzymatic antioxidant system
- Total antioxidant status (TAS) is the total antioxidant status
of plasma basing on the ability of inhibiting and combating the oxidants ofantioxidants including all the antioxidants in the body wich include a lot ofprotection systems to prevent from the adverse effects of free radicals andperoxide phenomenon for the body
1.2 The Mechanism of effect, capacity of generating free radicals, inhibiting antioxidant system of inorganic lead
1.2.1 Mechanisms of common effects
Lead entering into the body will inhibit and connectselectively with enzyme system, biomolecular having -SH group andcause several important biochemical disorders of cells
1.2.2 Mechanism of generating free radicals, inhibiting antioxidant system of inorganic lead
Inorganic Lead induces to oxidative stress by two opposingmechanisms closely linking to each other: stimulating the formation
of free radicals and reducing the antioxidant ability of the body.
- Stimulating the generation of free radicals: free radicals areformed from four main sources such as (1) the enolization andoxidation process of aminolevulinic acid (ALA), (2) the self-
Trang 6oxidation of oxyhemoglobin, (3) the enhancement of activity ofoxidative enzymes, (4) the oxidation of nitric oxide by free radicals
- Inhibiting the antioxidant system: Lead associates with -SHgroups to reduce level of GSH, GR, G6PD activity and GSH/GSSHratio Lead reduces the absorption of microquantity elements such asselenium, Cu, Zn, therefore reducing the activity of antioxidant enzymessuch as GPx, SOD, CAT and increasing reactivity of the membranes tooxidative attacks
1.3 Antioxidant effects of biomass Panax vietnamensis
1.3.1 Chemical composition
Panax vietnamensis biomass consists of main chemical
ingredients such as saponin whose total content is 2.01% In which,the content of ginsennosids such as Rg1, Rb1, Rg1 is 0.31%, 0.36%,0.15% respectively
CHAPTER 2- RESEARCH OBJECTS AND METHODS 2.1 Research objects
2.1.1 Study labor environment
Study on characteristics of microclimate and lead level in theair in labor environment
2.1.2 Study on humans
- Objects: 165 workers working in primary detonatingexplosives (Zx factory); battery assembly workshop, plate electrodeworkshop (Vinh Phu Battery Joint Stock Company) directly exposing
to lead, are divided into 2 groups:
Trang 7+ Group I (55 workers) has blood lead level ≤ 10 µg/dL
+ Group II (110 workers) has blood lead level > 10 µg/dL
+ Group II is divided into 2 small groups: Group IIA (86workers): blood lead level from 10 µg/dL to < 40 µg/dL and group IIB(24 workers): blood lead level ≥ 40 µg/dL
- Criteria to choose:
+ Time to work in the environment directly exposing to lead
is ≥ 5 năm, and continuous Not expose to other toxic elements Andparticipate in the study voluntarily
+ Exclusion criteria: acute exacerbations of chronic diseases,malignant diseases, diabetes mellitus, hypertension, kidney diseases,acute and chronic hepatitis, liver failure and autoimmune disease
- Choose all workers in the criteria and not in exclusioncriteria into the research
2.1.3 Study on animals
* Experimental animals: 360 male white housemice, 20
-25 gram, divided into 3 lots
- Control lot (108 mice) (lot 1)
- Lot infected lead acetate (108 mice) (lot 2)
- Lot infected lead acetate and drinking/with SNLSK toprotect (108 mice) (lot 3)
- 36 mice were killed and taken blood to experimentimmediately prior to testing
* Research materials
Lead acetate solution is provided by Division of TechnicalEquipment, Vietnam Military Medical Academy (manufactured byLucheng Qinda plastic injection Factory- China) Panax vietnamensisbiomass is newly manufactured and provided by the Center forResearch and Application of Military Medicine, Vietnam MilitaryMedical Academy Research tools are full enough for the experiment
2.2 Research methods.
2.2.1 Research methods of labor environment Survey microclimate
and lead dust concentration in labor environment
Trang 82.2.2 Research methods on workers
- Research design: descriptive and cross-sectional
- Research targets and techniques
+ Test lead concentration in blood
+ Test peripheral blood formula
+ Test blood biochemistry indexes
+ Identify content of free –SH group in blood, activity ofplasma peroxidase, erythrocyte superoxide dismutase (SOD), activity
of erythrocyte glutathion peroxidase (GPx), plasma malondialdehyde(MDA), plasma total antioxidant status (TAS)
2.2.3 Research methods on animals.
Research design: experimental, have intervention
* Mix lead acetate and Panax vietnamenis biomass: Mix
2,592g (2.592mg) of lead acetate into 1,296L (1.296mL) of distilledwater, obtain lead acetate solution Mix 24,30g (24.300mg) of Panaxvietnamenis biomass into 0,324L (324mL) of distilled water, obtainPanax vietnamenis biomass solution
* Toxic method: Semichronic toxic method under toxic model
of El-Sayed I H, Lotfy M et al (2006); Flora G, Gupta D et al (2013)
- Lot 1 (n = 108): drink 0,2mL of distilled water in morningsevery day, continuous in 15 days, 30 days and 45 days
- Lot 2 (n = 108): drink 0,2mL of lead acetate solution (20mg/kg/day) in mornings every day, continuous in 15 days, 30 daysand 45 days
- Lot 3 (n = 108): drink 0,1mL of Panax vietnamensisbiomass solution (375 mg/kg/day) After drinking SNLSK for onehour, mice are drunk 0,2mL of lead acetate solution (20 mg/kg/day),continuous in 15 days, 30 days and 45 days
* Method of blood drawn for testing: Mice are killed at the
time of experiment and blood is taken at two eye sockets
* Prior to the implementation of experiment: (36 mice).
- 12 mice are randomly selected, taken blood and dividedinto 2 parts to test blood formula and blood lead level
Trang 9- 12 next mice are randomly in the remainder, taken bloodand divided into 2 parts to test the activity of SOD, erythrocyte GPxand TAS, activity of peroxidase, plasma MDA, -SH.
- 12 remaining mice are taken blood to test biochemistry index
* After the implementation of experiment: (324 mice).
- At the time of 15 days, 30 days and 45 days after theimplementation of experiment, 108 mice (each lot: 36 mice) arerandomly selected, killed and taken blood for the experiment
* Research targets and techniques: as on humans
2.3 Data processing
The data is processed by medical statistical methods and usedsoftwares such as EpiInfo 2005 (Version 3.3.2), EpiCalc 2000
2.4 Ethnic issues in the research.
Ensure medical ethnics in the research
CHAPTER 3 RESULT OF RESEARCH 3.1 Result of research on human.
3.1.1 The mean blood lead level in the research groups.
Trang 10Blood lead level in group II, IIB have considerable change.
3.1.2.The result of test of SOD, GPx, peroxidase, -SH, MDA, TAS
in the research groups
Table 3.7 The change of some antioxidant index in group I, II Group
Content
Group I (n=55) ( X ±SD)
Group II (n=110)( X ±SD)
Table 3.11 The correlation of SOD, GPx, peroxidase, MDA, TAS
with blood lead level in group II
Trang 113.1.3 The result of test of peripheral blood formula in the research groups
Table 3.12 The change of peripheral blood formula in group I, II Group
Content
Group I(n=55) ( X ±SD)
3.1.4 The result of test of biochemical blood indices in the research groups.
Table 3.15 The change of AST, ALT, GGT, total bilirubin
in plasma in group I, II.
Group
Content Group I (n=55) ( X ±SD)
Group II (n=110) ( X ±SD)
Group II (n=110) ( X ±SD)
Trang 123.2 Result of research on animals.
3.2.1 The mean blood lead level in experimental mice.
Table 3.21 Blood lead level (BLL) in the research lots (L)
p21<0.05p32<0.05
Trang 133.2.2 The result of a number of index of antioxidant in experimental mice
Table 3.22 The change of activity of SOD of RBC at times
D o (n=12)
(a)
D 15 (n=12)(b)
D 30 (n=12)(c)
D 45 (n=12)(d)
pba>0.05pca>0.05pda>0.05
pba<0.05pca<0.05pda<0.05
pba<0.05pca<0.05pda<0.05
D 30 (n=12)(c)
D 45 (n=12)(d)
p21<0.05p32<0.05
