Ovary hormone deficiency and the age-related changes in post-menopausal women are subjected to a number of urological dysfunctions, including overactive bladder syndrome.
Green tea is a popular healthy drink worldwide and its extract catechin has strong anti-inflammatory and antioxidant properties. EGCG, the major type of catechin, is an antioxidant polyphenol flavonoid isolated from green tea. EGCG supplement could prevent ovariectomy-induced bladder dysfunction in a dose-related manner through its anti-oxidant, anti-fibrosis and anti-apoptosis effects.
OBJECTIVE: To evaluate whether green tea extract, epigallocatechin gallate (EGCG), could prevent ovariectomy-induced overactive bladder (OAB) and to investigate its antioxidant, anti-apoptotic and anti-fibrosis effects.
MATERIALS AND METHODS: In all, 48 female Sprague-Dawley rats were divided into four groups. After bilateral ovariectomy, the first group served as the ovariectomy control, the second group received EGCG 1 µM/kg daily i.p. injection after ovariectomy surgery, and the third group received EGCG 10 µM/kg daily i.p. injection. The fourth group was taken as the sham without ovariectomy surgery. The rats were killed after 6 months after ovariectomy surgery. Cystometrograms were performed for the measure of bladder overactivity. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) assay was used to evaluate apoptotic cells. Western immunoblots were performed to determine the expressions of inflammatory markers, apoptosis-associated proteins and oxidative stress markers.
RESULTS: Long-term ovariectomy significantly increased non-voiding contractions and decreased bladder compliance. Treatment with EGCG significantly increased bladder compliance and diminished non-voiding contractions. Ovariectomy significantly increased apoptotic cells and enhanced interstitial fibrosis in bladders. The expression of caspase-3 significantly increased, while that of Bcl-2 notably decreased after ovariectomy. Inflammatory and fibrosis markers, TGF-β, fibronectin and type I collagen expressions were significantly increased after 6 months of ovariectomy surgery. Treatment with EGCG significantly decreased TGF-β and type I collagen expressions. Oxidative stress markers, nitrotyrosine and protein carbonylation levels were significantly increased in the ovariectomy group. EGCG could attenuate this oxidative damage in dose-dependent fashion.
CONCLUSIONS: Ovariectomy increased oxidative damage, enhanced voiding frequency and decreased bladder compliance. EGCG could restore ovariectomy-induced bladder dysfunction in a dose-dependent fashion through antioxidant, anti-fibrosis and anti-apoptosis effects.
Written by:
Juan YS, Chuang SM, Lee YL, Long CY, Wu TH, Chang WC, Levin RM, Liu KM, Huang CH. Are you the author?
Graduate Institute of Medicine, Department of Urology, College of Medicine Excellence for Environmental Medicine, College of Medicine Department of Medical Genetics Department of Anatomy, College of Medicine Kaohsiung Medical University; Department of Urology Cancer Center, Kaohsiung Medical University Hospital Yuh-Ing Junior College of Health Care and Management Department of Urology, Chi-Shan Hospital, Department of Health, Executive Yuan; Department of Obstetrics and Gynecology, Kaohsiung Municipal Hsia-Kang Hospital, Kaohsiung, Taiwan; Albany College of Pharmacy, Albany, NY, USA.
Reference: BJU Int. 2012 May 28. Epub ahead of print.
doi: 10.1111/j.1464-410X.2012.11258.x
PubMed Abstract
PMID: 22639915
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