Oxidative stress and total antioxidant capacity in handball players

Abstract

Background:

Exercise training increases oxygen consumption, which was associated with the high generation of reactive oxygen species and markers of lipid peroxidation in the blood. The aim of this study was to assess the responses of total antioxidant capacity (TAC), biomarker of oxidative stress and erythrocyte, leukocyte and hematocrit (Hct) levels in plasma in athlete girls (handball players) and non-athlete girls.

Materials and Methods:

We evaluated two groups, which known as athlete and non-athlete women and they were similar in anthropometric characteristics. The athletic women engaged in the regular handball training 3 times a week for at least 6 months. However, non-athletic women didn’t have any regular activity over the last 6 months. Each subject referred to the lab and after 12 h fasting, the blood samples were taken for measuring all variables. Independent sample t-tests were used to identify the differences.

Result:

Significant differences were observed in malondehyde (P = 0.00), red blood (P = 0.00) cell and hemoglobin (P = 0.00). However, other evaluated factors such as of TAC, white blood cell, Hct and the mean corpuscular volume were higher in athletes than in non-athletes, but statistical significant differences weren’t seen in these variables between two groups.

Conclusion:

Regular exercise training for handball players may increase the activity of antioxidant enzymes and blood cells and reduces oxidant production.

INTRODUCTION

Exercise training increases oxygen consumption by the whole body particularly by muscles. The increase in oxygen uptake during the strenuous exercise is associated with the excessive generation of reactive oxygen species (ROS) and markers of lipid peroxidation in the blood.[1,2] In addition, the antioxidant enzymes, which constitute a defense mechanism against ROS affect by the exercise. It has been reported that insufficient levels of antioxidant during the intensive exercise training and imbalance between the expression of ROS and biological system's ability to remove the free radicals lead to the cellular loss of redox homeostasis and oxidative damage in lipids, proteins and consequently result in oxidative stress in cells and tissues.[3] Oxidative stress, which is a well-established mechanism of cellular injury plays a significant role in the development of many diseases such as diabetes, cancer, cardiovascular disorders, influenza and others.[4]

On the other hand, according to many studies, regular exercise training leads to an increase in the antioxidant enzymes level and their activities in the muscles and repair the resulting damage from ROS and lipid peroxidation.[5,6,7]

Since handball is considered as repeated sessions of exercise, competitive games and high volume of physical demanding exercise that places important stress on a player's aerobic metabolism and it involves a large number of anaerobic actions such as body contact, repeated accelerations, sprints, jumps, throwing, blocking, pushing and rapid changes in moving directions may have effects on biomarkers of oxidative stress and total plasma antioxidants. To our knowledge, there has not been any report regarding the responses of total antioxidant capacity (TAC), Malondialdehyde (MDA) as a biomarker of oxidative stress and erythrocyte, leukocyte and hematocrit (Hct) levels in plasma in athlete women (handball players). Hence, the aim of this study was to compare the effect of handball training on these variables between athlete women and non-athlete women.

MATERIALS AND METHODS

In this study, we evaluated two groups that were the university students. The case group was comprised of 15 athlete women (handball players) and control group was consisted of 15 non-athletic girls. The athletic women engaged in the regular handball training 3 times a week for at least 6 months. However, the subjects in the control group didn’t have any regular activity over the last 6 months. All participants had given written informed consent and they were completed the questionnaire including demographic information, medical history, smoking and diet. All subjects were healthy without familial or personal history of diseases and none of them was taking any drugs, coffin, vitamins and antioxidant supplements. In addition, none of them was following a special diet and they prohibited to consume too much fish oil, soya, sunflower seeds, cacao, fruits, vegetable and multivitamins which affected the results of the test.

In addition, having the normal menstrual cycles had been emphasized. The 3^rd day of their menstrual period, each subject referred to the lab and after 12 h fasting, the blood samples were taken by the biologist for measuring MDA, TAC and red blood cell (RBC) and white blood cells (WBC) counts, hemoglobin (Hb), Hct and the mean corpuscular volume (MCV). Samples were maintained in the coldchamber (−18°C) for 20 min until separation by centrifugation at 2000 g for 15 min at (−18°C).

It should be noticed this study was approved by the Ethics Committee of the University. Independent sample t-tests were used to identify the differences between two groups. Results are expressed as mean and standard deviation (SD) and the level of significance was set at P < 0.05.

RESULT

A total of 30 university students were evaluated and they were separated into athletes and non-athletes. Athlete group (n = 15, age = 22.14 ± 2.30 years) and non-athlete group (n = 15, age = 23.18 ± 1.80 years). Independent sample t-tests were used to identify baseline differences among athlete and non-athlete groups. Anthropometric characteristics of them are shown in Table 1. Both groups were of similar age, weight, height and body mass index. In addition, for comparison the two groups, we used independent t-test either [Table 2]. Significant differences were observed in MDA, RBC and Hb. However, other evaluated factors such as TAC, WBC, Hct and MCV were higher in athletes than in non-athletes, but statistical significant differences weren’t seen in these variables between two groups.

Table 1.

Anthropometric characteristics of two groups

Table 2.

Oxidative stress, total antioxidant capacity and hematological indexes in athlete group and non-athlete group

DISCUSSION

In this study, we found that MDA level in the athlete group was lower than in the non-athlete group. In addition, there were significant differences in the level of RBC and HB between two groups, which were higher in the athlete group.

The activities of TAC, WBC, HCT and MCV in the athlete group were greater than the non-athlete group; however, these differences weren’t statistical significant.

There were many studies that proposed our results.[8,9] For example, Aslan et al. investigated the effect of regular exercise training for 5 weeks and concluded that regular exercise makes individuals stronger against oxidative stress and increases antioxidant defense system and provides a healthy life.[10]

Another study demonstrated that a single handball game in elite athletes induces the oxidative modification in plasma and erythrocyte macromolecules as well as by changes in the enzymatic and non-enzymatic antioxidant system.[11]

In addition, the finding of Brites et al. showed that regular training has beneficial effects in plasma antioxidant status in soccer players in comparison to sedentary controls.[1]

Furthermore, Lovlin et al. which surveyed two kinds of exercise training concluded that exhaustive maximal exercise induces free radical generation while short periods of submaximal exercise may inhibit it and lipid peroxidation.[12]

In this regard, Afzalpour et al. suggested a correlation between physical training and improvement in the antioxidant defense system.[13]

The study of Ramel et al. proved that even regular resistance training partly prevents lipid peroxidation during exercise.[14]

Another related study considered the effects of aerobic and anaerobic training on serum lipid peroxidation levels and antioxidant enzyme activities so that, the results suggested aerobic training increased erythrocytes activity in plasma, but anaerobic training had no effect.[15]

Another examination revealed that long-term exercise training increases resting levels of erythrocyte in the exercise group compared with the control group; furthermore, antioxidant enzyme activities were increased following long-term exercise training.[16,17]

On the basis of the investigations, we can notify strenuous exercise in people causes disorders of the homeostasis and it may increase oxidant levels and oxidative stress.[2] The condition of oxidative stress develops when the balance between oxidants and antioxidants is interrupted owing to depletion of antioxidants or excess gathering of ROS; and consequently, MDA which is a marker of lipid peroxidation presents.[8,18] According to the article, muscles adapt to exercise training by increasing gene expression in the regulation of antioxidant enzymes.[18]

On the other hand, high levels of cytoplasmic antioxidants are found in RBCs, which work against ROS to protect the RBC from the harmful potential of oxidative stress. In fact, to encounter with the destructive effects of ROS, RBCs have effective antioxidative enzyme systems that nullify the reactive oxidants. Regularly performed exercise might induce an adaptive enhancement in skeletal muscle and the erythrocyte of the defense mechanisms that protect against free radical damage in athletes.[3]

Like our study, Kelle et al. observed the significant increases in RBC count, Hb concentration, WBC and Hct after the half-marathon that were the result of exercise before the race.[19]

It should be noted if our investigation didn’t show any statistical significant in some variables and if we observed some variations with other studies; we can deduce, these differences may be resulted from sex differences, subjects’ population and even the kind, intensity and the period of exercise training.

We concluded that regular exercise training may increase the activity of antioxidant enzymes and reduces oxidant production and markers of lipids peroxidation like MDA. In fact, sequential bouts of handball training induce adaptations that increase the blood cells and some Hct levels to protect against ROS and prevent massive oxidative damage.