Examination of antioxidant effect of hesperetin on testicular tissue in rats that were exposed to tobacco smoke

Tobacco, part of the family Solanaceae genus Nicotiana, is a highly toxic plant. Its known that tobacco smoke exposure causes respiratory system diseases, several cancer types and chronic cardiovascular diseases. It is suggested that this diseases arise because of the oxidative stress on tissues created by tobacco smoke. Toxic substances in tobacco smoke which are carried to every part of the body by blood, are likely to change the balance between oxidant - antioxidant systems against tissues. Flavonoids are a large group of phenolic compounds that are widely distributed in plants. Several properties have been reported from flavonoids, such as antioxidant, antimicrobial and antiiflammatory effects. Hesperetin is one the most abundant flavonoids found in citrus fruits, such as lemons, oranges and grape fruits. In our study, it is aimed to examine the protective effects of hesperetin against oxidative damage on testis tissue caused by tobacco smoke exposure. In this study, 8 weeks old and average 200±10 grams weight twenty-four male Spraque-Dawley rats were used. The rats were divided randomly into 4 equal groups: group I (Control), group II (Tobacco smoke), group III (Tobacco smoke + corn oil) and group IV (Tobacco smoke + hesperetin). The rats in group II, III and IV were exposed to tobacco smoke 1 hour twice a day. In addition to tobacco smoke exposure, 50 mg/kg hesperetin (dissolved in corn oil) was applied to the rats in group IV by oral gavage. Equal amount of corn oil used in solving hesperetin was applied to the rats by oral gavage in group III . At the end of the 12 weeks experimental period, rats were decapitated. Testicular tissues were removed and processed by using routine parafine techniques. The testis slides were stained by H&E, PAS and Masson's Trichrome methods. Also TUNEL methods and eNOS stain were applied. Biochemical analyzes on blood samples and sperm analyzes on sperm samples were performed. A significant decrease of percentage of body weight change was detected in tobacco smoke and tobacco smoke + corn oil groups when compared with control group. Percentage of body weight change in tobacco smoke + hesperetin group, a significant decrease was detected compared with the other groups. There was no statistically difference detected in weights of right testis, left testis, epididymis, prostate, seminal vesicle and relative testis weight, between the groups. The difference of sperm motility and sperm concentration between the groups was found no statistically significant. A significant increase in abnormal sperm amount was detected in tobacco smoke group compared with control group. It was found that reduction in the amount of abnormal sperm in tobacco smoke + hesperetin group compared with tobacco smoke group. In rat testis tissues of tobacco smoke group; degeneration in germinative epitelium, atrophic tubules, vascular congestion, seperation in seminiferious tubule basement membranes, edema in interstitial area and immature cell debris in tubule lumen were detected. The similiar findings of tobacco smoke group were found in tobacco smoke + corn oil group. Significant improvement were observed in seperation of seminiferious tubule basement membranes, germinative epitelium degeneration, vascular congestion and intersititial edema in rat testis tissues of tobacco smoke + hesperetin group. A significant increase of TUNEL positive cells in tobacco smoke and tobacco smoke + corn oil groups was detected, compared to the control group. The number of TUNEL positive cells in tobacco smoke + hesperetin group was observed similar to control group. A significantly increased eNOS immunoreactivity was observed in tobacco smoke and tobacco smoke + corn oil groups compared to the control group. Also decreased eNOS immunoreactivity was detected in tobacco smoke + hesperetin group. A significant increase was detected in the levels of MDA, in tobacco smoke and tobacco smoke + corn oil groups compared with the control group. It was found that hesperetin administration reduced the MDA levels similar to the control group. CAT and GSH-Px enzyme activities in tobacco smoke and tobacco smoke + corn oil groups were significantly decreased compared to the control group. Also significantly increase in GSH-Px enzyme activities was detected in tobacco smoke + hesperetin group compared with the tobacco smoke and tobacco smoke + corn oil groups. But CAT activities in tobacco smoke + hesperetin group wasn't different from the CAT levels of tobacco smoke and tobacco smoke + corn oil groups. As a result of our study, it was detected that exposure to tobacco smoke negatively effects the male reproductive system. It was also observed that hesperetin, which is used as a protector against tobacco smoke exposure, decreases the negative effects of tobacco smoke prominently by means of its antioxidant property.