unsaturated fatty acids in fats are omega-3 and omega-6 fatty acids both of which play fundamental roles in body metabolism .
omega-3 fatty acids are classified into three groups of alfa - linolenic acid ( ala ) , docosahexaenoic acid ( dha ) , and eicosapentaenoic acid ( epa ) ( 1 ) .
it appears that omega-3 fatty acid fulfills its biological effects by changes in lipid membrane or by directly activating the substrates for metabolism .
the role of omega-3 fatty acids in body is to fight with various diseases and inflammation ( 2 ) .
therefore , inflammatory responses are necessary in preventing diseases and it seems that the true balance in consuming omega-3 and omega-6 fatty acids can help the issue ( 1 ) .
the word  cytokine  is applied to a group of public regulatory factors including lymphokines made of lymphocytes and monokines made of monocytes ( 5 ) .
although il-17 is derived from a t cell , it is a pre - inflammatory cytokine , and it is assumed to have some role in progression of various inflammatory diseases , secretion of il-16 , and activating neutrophil in the tissue ( 6 ) .
the prognosis of inflammation and pathogenic factors in the body , on the other hand , is one of the most important and sensitive roles of immune system undertaken by some proteins .
quantity of the proteins in plasma and serum are changed due to the factors such as inflammation called acute phase proteins ( app ) ( 7 ) .
the role of most of these proteins is to decrease the inflammatory damages in tissues ( 8) .
the c - reactive protein ( crp ) is one of the acute phase proteins produced by liver and is one of the primary indicators of inflammation in the body ( 9 ) .
measuring crp is the best way to diagnose tissue damages due to its rapid increase at the onset of the tissue damage and its rapid decrease soon after the recovery .
physical activity is one of the ways that causes inflammation ( 10 ) . in the past two decades
, it is said that the physical activity has deep impacts on immune system , and the metabolic changes resulting from physical activity with muscle contraction and hormonal changes can be found in some organs like liver and adipose tissue ( 10 ) . in some studies on the effect of physical activity on crp and il-17 , the intensity of training has been highly emphasized . for example , the results of a study showed that one session intense training would increase il-17 in mice whereas one session physical activity with moderate intensity would not change il-17 production in mice . in this study , it was also found that the intense and moderate training would cause an increase in il-16 level in the trained mice ( 11 ) .
the result of the two types of intense and light training programs was also studied and the outcomes proved that after eight weeks , the level of this cytokine increased in a group with intense training but there was no alteration in another group ( 10 ) .
in contrast , golzari z. et al . found that if a combined program ( including warm - up , stretching exercise , aerobic exercise , strength training and a relaxation program at the end of each session ) is used for eight weeks , il-17 level do not increase ; in some people , there will be some decreaseas a result of low level of training intensity ( 12 ) . on the other hand ,
one of the training studies in this regard was performed by kim hj , et al .
they studied the effect of running distance during marathon ( 42.195 km ) and ultra marathon ( 200 km ) on crp and found that after marathon , the level of this protein does not change but after one day , it increased  times and after four days , it went back to its original level .
they also stated that the crp level after ultra marathon increased 40 times and it remained in the same level up to six days after the race ( 14 ) .
in contrast , in another study , it was stated that the crp level in healthy people and those with cardiovascular disease will decrease following twenty weeks of training with the intensity of 75% maximum oxygen consumption on ergometer bike but this decrease is more notable in subject patients ( 13 ) . 
 

therefore , regarding the effect of physical activity on inflammation , the purpose of this research is to study the effect and comparison of eight weeks intense aerobic or anaerobic physical training on possible changes in some systematic inflammatory markers ( crp , and il-17 ) .
we are also looking for possible effects of omega-3 fatty acids on crp and il-17 levels and if yes , it relation to the type of activity . 


 in this experimental study , 130 mice of syrian race with the age of 2 months and the weight of 351 grams were selected . at first
, 10 mice were killed to determine pretest variables ; unconscious was induced using ketamine ( 30 to 50 mg per kg body weight , intraperitoneally ) mixed with xylazine ( 3 to 5 mg per kg body weight , intraperitoneally ) and then blood samples were taken from their tail .
the rest of mice were randomly divided into six groups including control group ( n=20 ) , supplement ( n=20 ) , aerobic exercise ( n=20 ) , anaerobic exercise ( n=20 ) , supplement - aerobic ( n=20 ) , and supplement - anaerobic ( n=20 ) .
the mice were kept in separate cages ( 6 mice per cage ) , with a mean temperature of 232 c and a light cycle of 12 hours light and 12 hours darkness .
the aerobic training program included 8 weeks of running on treadmill , 5 sessions per week ( 15 ) . in order to get familiar with the treadmill , the aerobic exercise and aerobic - supplement groups began to run on treadmill for one week , with the speed of 5 meters per minute and zero slopes for 10 minutes .
after getting familiar with the treadmill , the speed increased to 7 meters per minute , the slope raised to 5 degrees and the duration to 15 minutes . on the other hand ,
the anaerobic training program included 8 weeks of running on treadmill , 3 sessions per week ( 10 ) .
the mice in the anaerobic and supplement - anaerobic groups ran on the treadmill for one week ( 3 sessions ) with the intensity of 12 meters per minute .
the training program included the speed , slope , and duration of running on treadmill ( see the aerobic program in table 1 and the anaerobic program on table 2 ) . 


table 1 

 anaerobic exercise program ( speed , slope and time ) 
 training sessionsno . of cyclesspeed ( minute / meter)slope ( degree)time ( second)rest between cycles ( minute)1 - 632453017 - 842453019 - 124271030113 - 165271030117 - 185301530119 - 2463015301 

 table 2 

 aerobic exercise program ( speed , slope and time ) 
 daysvariable 
 1 
  week 

 2 
  week 

 3 
  week 

 4 
  week 

 5 
  week 

 6 
  week 

 7 
  week 

 8 
  week 
 mondayspeed ( m / min)1010121317192227 
 slope ( degree)510151515151818 
 time ( m)1515606060606060tuesdayspeed ( m / min)1010121317192227 
 slope ( degree)513151515151818 
 time ( m)1515606060606060wednesdayspeed ( m / min)1012121317192227 
 slope ( degree)813151515151818 
 time ( m)1515606060606060thursdayspeed ( m / min)1012121317192227 
 slope ( degree)815151515151818 
 time ( m)1515606060606060fridayspeed ( m / min)1012121317192227 
 slope ( degree)1015151515151818 
 time ( m)1545606060606060 
 
 the mice in three groups of supplement , aerobic - supplement and anaerobic - supplement were fed ( using gavage ) 0.2 ml ( 0.06 ml / g of body weight ) of fish oil ( omega 3 ) including dha and epa for 8 weeks on a daily basis.at the end of the exercise , the blood samples from each group were taken in order to measure the crp and il-17 levels .
measurement were performed using elisa kits , mouse - kit ( i d labs inc . , hungary ) for il-17 and crp - kit ( neflometry , england ) for crp . 
 

the analysis of variance ( anova ) was used to determine the differences among the groups ; if significant , tukey s post hoc test was used .

 in this experimental study , 130 mice of syrian race with the age of 2 months and the weight of 351 grams were selected . at first
, 10 mice were killed to determine pretest variables ; unconscious was induced using ketamine ( 30 to 50 mg per kg body weight , intraperitoneally ) mixed with xylazine ( 3 to 5 mg per kg body weight , intraperitoneally ) and then blood samples were taken from their tail .
the rest of mice were randomly divided into six groups including control group ( n=20 ) , supplement ( n=20 ) , aerobic exercise ( n=20 ) , anaerobic exercise ( n=20 ) , supplement - aerobic ( n=20 ) , and supplement - anaerobic ( n=20 ) .
the mice were kept in separate cages ( 6 mice per cage ) , with a mean temperature of 232 c and a light cycle of 12 hours light and 12 hours darkness .
the aerobic training program included 8 weeks of running on treadmill , 5 sessions per week ( 15 ) . in order to get familiar with the treadmill , the aerobic exercise and aerobic - supplement groups began to run on treadmill for one week , with the speed of 5 meters per minute and zero slopes for 10 minutes .
after getting familiar with the treadmill , the speed increased to 7 meters per minute , the slope raised to 5 degrees and the duration to 15 minutes . on the other hand ,
the anaerobic training program included 8 weeks of running on treadmill , 3 sessions per week ( 10 ) .
the mice in the anaerobic and supplement - anaerobic groups ran on the treadmill for one week ( 3 sessions ) with the intensity of 12 meters per minute .
the training program included the speed , slope , and duration of running on treadmill ( see the aerobic program in table 1 and the anaerobic program on table 2 ) . 


table 1 

 anaerobic exercise program ( speed , slope and time ) 
 training sessionsno . of cyclesspeed ( minute / meter)slope ( degree)time ( second)rest between cycles ( minute)1 - 632453017 - 842453019 - 124271030113 - 165271030117 - 185301530119 - 2463015301 

 table 2 

 aerobic exercise program ( speed , slope and time ) 
 daysvariable 
 1 
  week 

 2 
  week 

 3 
  week 

 4 
  week 

 5 
  week 

 6 
  week 

 7 
  week 

 8 
  week 
 mondayspeed ( m / min)1010121317192227 
 slope ( degree)510151515151818 
 time ( m)1515606060606060tuesdayspeed ( m / min)1010121317192227 
 slope ( degree)513151515151818 
 time ( m)1515606060606060wednesdayspeed ( m / min)1012121317192227 
 slope ( degree)813151515151818 
 time ( m)1515606060606060thursdayspeed ( m / min)1012121317192227 
 slope ( degree)815151515151818 
 time ( m)1515606060606060fridayspeed ( m / min)1012121317192227 
 slope ( degree)1015151515151818 
 time ( m)1545606060606060 
 
 the mice in three groups of supplement , aerobic - supplement and anaerobic - supplement were fed ( using gavage ) 0.2 ml ( 0.06 ml / g of body weight ) of fish oil ( omega 3 ) including dha and epa for 8 weeks on a daily basis.at the end of the exercise , the blood samples from each group were taken in order to measure the crp and il-17 levels .
measurement were performed using elisa kits , mouse - kit ( i d labs inc . ,
hungary ) for il-17 and crp - kit ( neflometry , england ) for crp . 

the analysis of variance ( anova ) was used to determine the differences among the groups ; if significant , tukey s post hoc test was used .

 the results showed that there was a significant difference in interleukin-17 level among the groups ( p<0.05 ) .
this research showed that the supplement consumption ( without physical activity ) causes a significant decrease in il-17 level ( p<0.05 ) but applying both training programs leads to a significant increase in this cytokine ; this increase is more notable after doing anaerobic exercise ( p<0.01 ) .
furthermore , when aerobic exercise is together with supplement consumption ( aerobic - supplement group ) there is no difference between the results of this group and the aerobic group ; but when the supplement consumption is together with anaerobic exercise , it does nt increase and there is no significant change in il-17 level ( table 3 ) . on the other hand
, the results of recent research showed that there is a significant difference in the levels of crp among the groups ( p<0.05 ) .
comparing the average crp before and after the exercise in the groups indicated that the supplement consumption results in a notable decrease in this protein . during the physical activity , the crp level will increase but this increase is more notable in aerobic group ( p<0.01 ) ( table 4 ) .
there is also a significant difference between supplement - aerobic group and supplement - anaerobic group and the results showed that the supplement consumption with aerobic exercise will only decrease the slope whereas the supplement consumption with anaerobic exercise makes no significant change . 
 
 
* stars indicate there is a significant difference ( p<0.05 ) 
 
  * * stars indicate there is a significant difference ( p<0.01 ) 
 
  * stars indicate there is a significant difference ( p<0.05 ) 
 
  * * stars indicate there is a significant difference ( p<0.01 ) 


 the results of current research show that there is a significant difference in il-17 and crp plasma levels after epa and dha supplement consumption along with physical activity .
these dependent variables are involved in regulation of immunity and inflammatory responses ( 16,17 ) .
although pre - inflammatory cytokines are necessary for immunity defense , the maximum production of these cytokines can cause the inflammation and then the injury to skeletal muscle , weakness and increased risk of infection ( 18 ) il-17 cytokine is able to activate the macrophages , the fibroblasts , secretion of il-1 , il-6 , and il-8 cytokines , the secretion of e2 prostaglandins and nitric oxide ( 19 ) .
some researchers believe that il-17 plasma levels may be a helpful biochemical marker to determine the acute inflammation presented in skeletal muscle ( 20,21 ) .
as you can see in table 3 , anaerobic exercises caused the highest levels of il-17 .
the results of current research , like some other researches , show that the intensity of the exercise is a key factor ( 12 ) .
another research indicated that in an activity with high intensity , il-17 level was increased but in a group with low intensity , there was no change ( 11 ) .
studied the effect of four weeks physical activity on treadmill and the results showed that il-17 had decreased .
these researchers also stated that the main cause of this decrease was probably due to the low intensity of the exercise ( 19 ) . in current research
, it was also specified that the changes to il-17 levels differed in physical activities with various intensities ( aerobic & anaerobic ) and this increase was more in anaerobic exercises ( it should be noted that there is any way some increase in aerobic exercises )
. however , these results are inconsistent , compared with some other studies ( 19 ) , and it can be due to the number of weeks . similar to this , duzova h.et al also stated that the production of il-17 was increased by high intensity or long time activities but it was not increased in a group with short time physical activity ( one week ) with moderate intensity ( 11 ) .
the involved mechanism is probably due to the fact that the high intensity physical activity leads to the release of pre - inflammatory cytokines and these cytokines , in turn , will cause the production of anti - inflammatory cytokines such as il-2 , il-6 , and il-10 ( 6 ) .
it appears that the consecutive production of these pre- inflammatory and anti - inflammatory cytokines will cause il-17 to be produced by blood peripheral leukocytes and skeletal muscle ( 17 ) .
the results of supplement consumption along with aerobic and anaerobic exercises should also be taken into consideration .
the results of current research show that the supplement consumption in aerobic group did nt have any effect on il-17 levels ( 129.06 pg / ml in aerobic group and 129.12 pg / ml in aerobic - supplement group ) ; but omega-3 consumption along with anaerobic physical activity prevents the increase in this cytokine , and there is no change in il-17 level as compared with the values before the exercise ( after the exercise completion , 143.96 pg / ml in anaerobic group and 129.12 pg / ml in aerobic - supplement group ) .
the reason for the differences in supplement consumption can be related to the different il-17 levels as a result of aerobic and anaerobic physical activities .
it is foreseen that the il-17 level should be reached to the extent so that the effect of omega 3 supplement consumption can be observed . .
therefore , a threshold for il-17 production for the effect of supplement consumption can be mentioned ( meaning that il-17 level does nt reach the desired threshold to make the supplement effective as a result of aerobic exercise ) . with regard to the results of above studies
, it can be said that the intensity or duration of the physical activity is a key factor in increased production of interleukin-17 , but the supplement consumption can change the result .
thus , it was specified that the supplement consumption , the supplement consumption together with aerobic exercises and supplement consumption along with anaerobic exercises respectively will cause a decrease in il-17 ( as compared with control group ) , will have no effect on il-17 ( as compared with aerobic group ) , and will prevent the il-17 increase ( as compared with anaerobic group ) . 
 

the crp normal range in adults is about 0.8 - 5 ml per liter blood , but it can be increased up to 1000 times as a result of infection or physical activity because the amount of secretion of apps depends directly or indirectly on factors such as the production of cytokines and t cells ( 8) .
the gathered information shows that the crp plays an important role in inflammation ( 7 ) .
this acute phase reactant can be found in human arteriosclerosis plaque together with ldl ( 8) .
crp stimulates the expression of plaque in endothelial cells and enhances the adhesion of the plaque to these cells .
this information shows that crp is not merely an inflammation marker but a risk factor in turn ( 9 ) .
some researchers believe that the amount of production of this protein depends on the duration , intensity , type of exercise and the distance travelled by an individual ( 9 ) .
for example , in a study , researchers found that the level of this protein does nt change soon after marathons ; however , there is a remarkable increase after ultra - marathons ( 14 ) .
the results of current research indicate that the crp level in aerobic exercise group has increased more than the anaerobic exercise group ( 2.3 and 1.7 mg / l respectively ) .
it was also specified that the amount of this protein would increase more in exercises with more distance travelled .
table 4 shows that the supplement group has the least amount in crp and this indicates the effect of omega-3 consumption on this protein . in conformity with the result of current research ,
another study proved that omega-3 consumption for 8 weeks by 6 women and 6 men led to a crp decrease ( 2 ) . in another study , the researchers stated that consuming 6 grams of epa daily for 8 weeks would cause a decrease in the crp level from 11 mg / l to 8 mg / l ( probably due to a decrease in il-6 ) .
however , in contrast , the researchers in a study found that consuming 4 grams of fish oil daily does nt increase the crp level in fat individuals .
short time supplement consumption ( one week ) has been mentioned as a reason for this finding ( 9 ) .
therefore , time is a key factor for supplement to be effective ( 9 ) . on the other hand
, this study showed that when the supplement is used , the level of crp increases in supplement - aerobic group less than the aerobic group ( without supplement consumption ) ; for instance , the crp level increases about 180% as a result of aerobic exercise and 64% when it goes with supplement consumption .
comparison of these four groups ( aerobic , anaerobic , supplement - aerobic and supplement - anaerobic ) reveals that supplement consumption has affected the crp level ( incremental changes with a crp milder slope in supplement - aerobic group as compared with aerobic group and insignificant increase in supplement - anaerobic group ) . why supplement consumption can not prevent its increase in aerobic exercises ( contrary to anaerobic exercises ) ?
it appears that the distance travelled and high level of this protein followed by aerobic exercise ( without supplement consumption ) is a reason .
it should also be noted that the supplement consumption led to a decrease in the the slope of crp increase . 


 finally , it can be said that epa and dha supplement consumption decreases the il-17 plasma level .
the results of this study shows that the amount of cytokine depends more on the intensity of exercise but the crp level depends more on the distance travelled .
besides , the effect of omega-3 consumption on these two variables depends on the type of exercise . 


 special thanks to dr.farhaddaryanoosh and animal lab personnels of shiraz medical sciences university for their full support to fulfill the work . 

 
 background : herein , we studied the effects of two different exercise protocols on il-17 and crp 
 plasma levels along with the anti - inflammatory effects of fish oil . 
 the purpose of the present study 
 was to investigate the effect of eicosapentaenoic acid ( epa ) and docosahexaenoic acid ( dha ) 
 consumption along with two different types of physical activities on il-17 and crp plasma levels in 
 trained male mice . 

 
 methods : a total of 130 adult male mice of syrian race with the age of 2 months and the weight of 
 351 grams were selected . at the beginning , 
 10 mice were killed in order to determine the amounts 
 of pre - test variables . 
 the rest of the mice were randomly divided into 6 groups including control 
 group ( n=20 ) , supplement ( n=20 ) , aerobic exercise ( n=20 ) , anaerobic exercise ( n=20 ) , supplementaerobic 
 exercise ( n=20 ) , and supplement - anaerobic exercise ( n=20 ) . 
 blood samples were withdrawn 
 from the tail under intraperitoneal ketamine and xylasine anaesthesia . 
 the anaerobic training program 
 included 8 weeks of running on treadmill , 3 sessions per week ; the aerobic training program 
 included 8 weeks of running on treadmill , 5 sessions per week . at the end of the training program , 
 
 the blood sample from each group was taken in order to measure the crp and il-17 levels . 
 the 
 analysis of variance ( anova ) was used to determine the differences among the groups . 

 
 results : the results showed that there was a significant difference in il-17 and crp plasma levels 
 between the groups after 8 weeks ( p<0.05 ) . 

 conclusion : following the two different training programs , both il-17 and crp plasma levels increased , 
 although these observed increases were not same for two measured variables . the results 
 might also show that the effect of the supplement depends on the type of training . 
 
Introduction
Methods
Data
 Statistical Analysis
Results
Discussion
Conclusion
Acknowledgements