Long Term Effect of Echinochrome A on the Extracellular Matrix of Vocal Folds Lamina Propria in Ovariectomized Rats

Abstract

Background and Objectives Voice problems after menopause are caused by extracellular matrix (ECM) changes in the vocal fold lamina propria. Echinochrome A (ECH), which is known to a strong anti-oxidant, was injected into ovariectomized rats (OVX) to evaluate the effect on the ECM of the vocal fold lamina propria.Materials and Method Sprague-Dawley female rats were randomly divided into three groups as follows: group I (sham-operated rats, SHAM), group II (OVX), group III (ovariectomized rats injected with ECH, OVX+ECH). Rats were sacrificed 12 weeks after ovariectomy.Results ECH treatment had no effect on the levels of estradiol and expression of estrogen receptor β in vocal fold. The expression of Has2 and Has3 were decreased in the OVX and increased with ECH treatment. The expression of Col1a1, Col1a2, and Col3a1 were decreased in the OVX group, but significantly elevated in the OVX+ECH group. The expression of Eln was decreased in the OVX group, but the level of Eln increased in the OVX+ECH group. The expression of matrix metalloproteinases (MMP)-1, 8, and 9 was increased in the OVX group, but the expression of MMP-1 and 8 were decreased after ECH treatment. ECH treatment had no effect on 4-hydroxynonenal in vocal fold, superoxide dismutase, catalase, and glutathione peroxidase were decreased in the OVX and increased with ECH treatment.Conclusion It was confirmed that ECH injection for 12 weeks suppressed changes in collagen, elastin, and MMPs expression caused by menopause. These findings suggest that ECH can be used as a novel alternative therapy for postmenopausal voice changes.