The effect of anthocyanin on the prostate in an andropause animal model: rapid prostatic cell death by apoptosis is partially prevented by anthocyanin supplementation

Abstract

Purpose: To evaluate the anti-apoptotic effect of the antioxidant reaction of anthocyanin on the prostate in an andropause animal model.

Materials and methods: Sprague-Dawley rats were divided into three groups (n=12 in each): control (Group I), andropause (Group II), andropause treated with anthocyanin (Group III). For induction of andropause, Group II and III underwent bilateral orchiectomy. Group III was treated with daily oral anthocyanin (160 mg/kg) for 8 weeks. After 8 weeks, the rats were sacrificed and their blood and prostates were examined pathohistologically and evaluated for oxidative stress and apoptosis. Oxidative stress was assessed by the activity of superoxide dismutase (SOD) and apoptosis in the prostate was identified by terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling assay.

Results: Group II showed markedly increased activity of SOD in serum over that observed in Group I, whereas the rats in Group III showed reduced oxidative stress compared to Group II. Despite no significant differences in prostate weight between Group II and III (p=0.078), the apoptotic index was significantly greater in Group II than Group I, and was significantly lesser in Group III than Group II.

Conclusions: We suggest that the oxidative stress caused by low testosterone may be another inducer of apoptosis, and this apoptosis may partly contribute to the overall apoptosis of the prostate in the andropause animal model. Therefore, anthocyanin supplementation may contribute to preventing excessively rapid cell death by apoptosis in the prostate in an animal model of andropause.

Keywords: Andropause; Anthocyanins; Antioxidants; Apoptosis.

Fig. 1

Prostate weights in each experimental groups. Group I: control group, Group II: andropause, Group III: andropause treated with anthocyanin. ^aSignificant difference (p<0.05) compared with the Group I.

Fig. 2

H&E stain of the prostate in each experimental groups. (A) It shows normal prostate gland (Group I). (B) All acini of the prostate gland were diffusely atrophic. Each atrophic acini formed a relatively certain round shape and were separated by thick fibrohyaline collar and stromal fibrosis (Group II). (C) All acini of the prostate gland were diffusely atrophic. The variable sized and shaped acini closely packed together and lined by atrophic epithelium. Also fibrohyaline collar and stromal fibrosis, separated each acini, were decreased (Group III).

Fig. 3

Comparisons of the activity of superoxide dismutase (SOD) and apoptotic index in each experimental groups. Group I: control group, Group II: andropause, Group III: andropause treated with anthocyanin. ^aSignificant difference (p<0.05) compared with the Group I. ^bSignificant difference (p<0.05) compared with the Group II.

Fig. 4

Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) stain in each experimental groups (×200). (A) A fewer cells were stained positively (Group I). (B) Nearly almost cells were stained positively (Group II). (C) Positively stained cells were decreased in Group III compared with Group II.