Influence of Fermented Red Clover Extract on Skeletal Muscle in Early Postmenopausal Women: A Double-Blinded Cross-Over Study

Effects of transdermal estrogen therapy on satellite cell number and molecular markers for muscle hypertrophy in response to resistance training in early postmenopausal women

PURPOSE

To investigate the effects of resistance training with or without transdermal estrogen therapy (ET) on satellite cell (SC) number and molecular markers for muscle hypertrophy in early postmenopausal women.

METHODS

Using a double-blinded randomized controlled design, we allocated healthy, untrained postmenopausal women to perform 12 weeks of resistance training with placebo (PLC, n = 16) or ET (n = 15). Muscle biopsies obtained before and after the intervention, and two hours after the last training session were analyzed for fiber type, SC number and molecular markers for muscle hypertrophy and degradation (real-time PCR, western blotting).

RESULTS

The analysis of SCs per Type I fiber showed a time x treatment interaction caused by a 47% decrease in PLC, and a 26% increase after ET after the training period. Also, SCs per Type II fiber area was lower after the intervention driven by a 57% decrease in PLC. Most molecular markers changed similarly in the two groups.

CONCLUSION

A decline in SC per muscle fiber was observed after the 12-week training period in postmenopausal women, which was counteracted when combined with use of transdermal ET.

CLINICAL TRIAL REGISTRATION NUMBER

nct03020953.

Short-Term Supplementation With Fermented Red Clover Extract Reduces Vascular Inflammation in Early Post-menopausal Women

The decline in estrogen at menopause poses a critical challenge to cardiovascular and metabolic health. Recently, a growing interest in the role of phytoestrogens, with a particular focus on isoflavones, has emerged as they can bind to estrogen receptors and may mimic the roles of endogenous estrogen. Fermented red clover extract (RC) contains isoflavones with superior bioavailability compared to non-fermented isoflavones, however little is known regarding the impact of isoflavones on cardiovascular and metabolic health. We assessed markers of vascular health in plasma and skeletal muscle samples obtained from healthy but sedentary early post-menopausal women (n = 10; 54 ± 4 years) following 2 weeks of twice daily treatment with placebo (PLA) or RC (60 mg isoflavones per day). The two interventions were administered using a randomized, double-blind, crossover design with a two-week washout period. Plasma samples were utilized for assessment of markers of vascular inflammation. There was a statistically significant reduction (~5.4%) in vascular cell adhesion molecule 1 (VCAM-1) following 2 weeks of RC supplementation compared to PLA (p = 0.03). In contrast, there was no effect of RC supplementation compared to PLA on skeletal muscle estrogen receptor content and enzymes related to vascular function, and angiogenesis. Supplementation with RC reduces vascular inflammation in early post-menopausal women and future studies should address the long-term impact of daily supplementation with RC after menopause.

Efficacy and safety of phytoestrogens in the treatment of perimenopausal and postmenopausal depressive disorders: A systematic review and meta-analysis

BACKGROUND

Depression is one of the most common and specific symptoms among menopausal women, leading to significant personal, family, and economic burdens. Some studies have shown that phytoestrogens can help relieve symptoms of depression.

OBJECTIVES

This systematic review and meta-analysis aim to assess the efficacy and safety of phytoestrogens in treating depression among menopausal women.

METHODS

A comprehensive search for relevant studies published until November 25, 2020, was conducted in PubMed, the Cochrane Library, Chinese Biomedical Literature Database, Web of Science, and EMBASE. Statistical analyses were performed with R 4.0.3.and Review Manager 5.4.

RESULTS

2183 studies were identified and 10 studies with 15 independent reports were included, involving 1248 participants. The quality of the four studies was assessed as high risk, six studies were assessed as unclear. The analyses conducted according random effects model indicated the significant positive effect on depressive symptoms for postmenopausal women compared with the placebo (SMD = -0.62; 95% CI = -1.13 to -0.12; Q = 45.62, df = 14, P < .01; I²  = 79%). The low dose phytoestrogens (25 mg/d ≤ dose ≤ 100 mg/d) have better effectiveness (SMD = -0.52; 95% CI = -0.85 to -0.20; I²  = 79%, P< .01) than high dose (dose > 100 mg/d) and ultralow dose (0 < dose < 25 mg/d), but showed no statistical significance (Q = 0.81 df = 2, P = .67). Isoflavones had better effectiveness (SMD = -0.48; 95% CI = -0.75 to 0.21; I²  = 75%, P < .01) than lignans of phytoestrogens (SMD = -0.22; 95% CI = -0.37 to 0.08; I²  = 0%, P = .96). The duration of intervention affects the efficacy of phytoestrogens (β = -0.03; 95% CI: [-0.05, 0.00]; P = .045). The effectiveness varies in regions. The adverse reactions frequently reported were gastrointestinal symptoms and cold or upper respiratory tract infection.

CONCLUSIONS

Phytoestrogen can relieve depression symptoms among menopausal, especially for postmenopausal women who take low doses(25 mg/d ≤ dose ≤ 100 mg/d) of phytoestrogens for a long-term duration. Although mild adverse reactions have been reported, phytoestrogen could be considered as a complementary treatment for postmenopausal depression.

Red Clover Isoflavones Influence Estradiol Concentration, Exercise Performance, and Gut Microbiota in Female Mice

In red clover (Trifolium pratense L.; RC) the main compound is isoflavones, which are selective estrogen receptor modulators for maintaining female health. Isoflavones exert antifatigue effects during exercise in high-temperature environments. This study aimed to investigate the effect of RC supplementation on gut microbiota composition to determine whether it improves intestinal barrier function and exercise performance. Female ICR mice were divided into four groups (n = 8 per group) and orally administered RC once daily for 6 weeks at 0 (vehicle), 308 (RC-1X), 615 (RC-2X), and 1,538 (RC-5X) mg/kg. RC supplementation decreased the fat mass and increased exhaustive swimming time, grip strength, and muscle glycogen in female mice. In the RC supplementation group, serum levels of lactate, ammonia, and creatine kinase decreased after swimming. The estradiol and progesterone levels were higher in the RC group than in the vehicle group. Regarding gut microbiota composition, the RC-2X group may increase intestinal health related to the microorganisms Pseudobutyrivibrio and Parabacteroide. Thus, the use of RC supplements as nutraceuticals could have positive effects on athletes' gut and overall health.