Effectiveness of natural S-equol supplement for premenstrual symptoms: protocol of a randomised, double-blind, placebo-controlled trial

Abstract

IntroductionPremenstrual syndrome (PMS) comprises a range of mood, behavioural and physical symptoms, and impairs many women’s quality of life. Isoflavones are expected to stabilise the natural fluctuation of the oestrogen cycle through their selective oestrogen receptor modulator-like activities that alleviate PMS symptoms. Equol, a metabolite of a soy isoflavone converted from daidzein by specific gut bacteria, has a greater bioavailability compared with other soy isoflavones. We aim to examine the effect of natural S-equol supplements on premenstrual symptoms.Methods and analysisThis study will enrol 124 women (aged 20–45 years) who have PMS symptoms and are non-equol producers in a double-blind, parallel, randomised, placebo-controlled trial, in which they will receive natural S-equol supplement (equol 10 mg a day) or placebo, orally, twice daily, for three menstrual cycles. The primary outcome measure (Daily Record of Severity of Problems total score) will be assessed during intervention cycles. To compare the primary outcomes between the S-equol group and the placebo group, the mean differences in the Daily Record of Severity of Problems total score between the two groups will be determined. The p values will be determined using Student’s t-test, where the significance level is 5% (two-sided).Ethics and disseminationThe institutional review board at Kindai University approved the study. The findings of this trial will be submitted to an international peer-reviewed journal. Abstracts will be submitted to national and international conferences.Trial registration numberUMIN000031815.

A Phosphotyrosine Switch in Estrogen Receptor β Is Required for Mouse Ovarian Function

“…Our previous cancer-related study shows that the ERβ-specific agonist S-equol elevates the same phosphotyrosine switch in cancer cells and antitumor CD8 + T cells and inhibits tumor growth in both xenograft and syngeneic tumor models ( Yuan et al, 2016 , 2021 ). S-equol is a natural compound with proven clinical safety and high tolerance in humans, based on multiple phase I and II clinical trials ( Setchell et al, 2005 ; Jackson et al, 2011 ; Takeda et al, 2018 ). Our finding of the importance of this ERβ molecular switch in supporting ovarian functions raises the distinct possibility that S-equol could be explored for potential treatment of infertility and other related reproductive disorders.…”

Psychometric Testing of the Japanese Version of the Daily Record of Severity of Problems Among Japanese Women

“…Japanese translation of the DRSP and the use of this Japanese version of the DRSP for our clinical trial were permitted by Endicott, who originally developed the English version. 16 We translated the DRSP into Japanese, and it was linguistically validated according to the general cross-cultural adaptation process in our previous study. 17 The back-translated version was verified for accuracy and equivalence by Endicott.…”

“…[8][9][10][11] The DRSP was originally developed in English by Endicott 12 and has since been translated into many languages, including German, 13 Portuguese, 14 and Chinese. 15 We translated the DRSP into Japanese for the purpose of this clinical study, 16 which is the first to use the Japanese version of the DRSP (DRSP-J). 17 The DRSP-J was linguistically validated according to the general cross-cultural adaptation process, but its reliability and validity have not been systematically evaluated.…”

Propriedades Fucionais Da Soja

“…Sintomas pré-menstruais podem afetar o humor, o comportamento e causar sintomas físicos (YONKERS et al, 2008), em 5% das mulheres os sintomas são severos e interferem na vida social bem como no trabalho (DIMMOCK et al, 2000). Segundo Takeda et al (2018) uma dieta com isoflavonas pode favorecer as mulheres contra os sintomas pré-menstruais, e a suplementação somente com metabólito S-equol pode ser uma estratégia segura á ser desenvolvida. Takeda et al (2018) teve como base um estudo feito com 144 mulheres de origem japonesa em idade reprodutiva, todas consumiram alimentos à base de soja contendo 50 mg de isoflavonas duas vezes ao dia.…”

“…Segundo Takeda et al (2018) uma dieta com isoflavonas pode favorecer as mulheres contra os sintomas pré-menstruais, e a suplementação somente com metabólito S-equol pode ser uma estratégia segura á ser desenvolvida. Takeda et al (2018) teve como base um estudo feito com 144 mulheres de origem japonesa em idade reprodutiva, todas consumiram alimentos à base de soja contendo 50 mg de isoflavonas duas vezes ao dia. Estas mulheres foram distribuídas em dois grupos distintos, o grupo controle teve uma produção de S-equol 17,9% maior do que o grupo de mulheres que apresentavam os sintomas pré-menstruais severos, mas em contrapartida tiveram efeitos positivos ao alívio dos sintomas.…”