Soymilk Improves Muscle Weakness in Young Ovariectomized Female Mice

Abstract

Estrogens play a key role in an extensive range of physiological functions in various types of tissues throughout the body in females. We previously showed that estrogen insufficiency caused muscle weakness that could be rescued by estrogen administration in a young female ovariectomized (OVX) mouse model. However, long-term estrogen replacement therapy increases risks of breast cancer and cardiovascular diseases. Soymilk contains plant-based protein and isoflavones that exert estrogen-like activity. Here we examined the effects of prolonged soymilk intake on muscle and its resident stem cells, called satellite cells, in the estrogen-insufficient model. Six-week-old C57BL/6 OVX female mice were fed with a dried soymilk-containing diet. We found that prolonged soymilk intake upregulated grip strength in OVX mice. Correspondingly, cross-sectional area of tibialis anterior muscle was significantly increased in OVX mice fed with soymilk. Furthermore, soymilk diet mitigated dysfunction of satellite cells isolated from OVX mice. Thus, these results indicated that prolonged soymilk intake is beneficial for improving muscle weakness in an estrogen-insufficient state in females.

Estrogen Receptor β Controls Muscle Growth and Regeneration in Young Female Mice

“…Recent studies demonstrated that ERα is involved in mitochondrial integrity ( Ribas et al., 2016 ), lipid metabolism ( Schweisgut et al., 2017 ), atrophy ( Ogawa et al., 2015 ), and regeneration ( Collins et al., 2019 ) in skeletal muscle. Although E2 preferably binds to ERα, we have found that consecutive intake of soymilk containing isoflavones, which preferentially bind to ERβ, ameliorated muscle atrophy and satellite cell dysfunction in ovariectomized female mice ( Kitajima et al., 2017 ; Kitajima and Ono, 2016 ), suggesting that ERβ signaling is also a factor that regulates both skeletal muscles and satellite cells. However, the roles of ERβ in skeletal muscle and satellite cells are poorly understood.…”

Naringenin Promotes Myotube Formation and Maturation for Cultured Meat Production

“…In general, ERs and estrogen form dimers and then bind to estrogen receptor binding elements to stimulate target gene transcription and regulate cell proliferation or differentiation [ 42 , 43 ]. ERs are mainly composed of two isoforms, estrogen receptor α (ERα) and estrogen receptor β (ERβ), both of which have been reported to be involved in muscle atrophy [ 44 ], muscle regeneration, and hypertrophy [ 45 , 46 , 47 ]. In this work, it was found that the pro-myogenesis role of NAR was related to ERβ.…”

From mitochondria to sarcopenia: role of 17β-estradiol and testosterone

“…In this context, oral intake of natural food sources containing phytoestrogens may be a good alternative. For example, intakes of soymilk containing isoflavones, an active estrogen-like substance, improve muscle weakness in OVX mice ( 152 ). Similar to 17β-estradiol replacement treatment, several investigators found the potential risks associated with androgen therapy ( 153 , 154 ).…”