Effects of dietary phytoestrogens on plasma testosterone and triiodothyronine (T3) levels in male goat kids

Preliminary Results on the Effects of Soybean Isoflavones on Growth Performance and Ruminal Microbiota in Fattening Goats

Soybean isoflavones (SIFs), a group of secondary metabolites, have antioxidant, anti-inflammatory, and hormone-like activities. Supplementation with SIFs in the diet was reported to promote lactation performance in ruminants. The present study was performed to further decipher the effect of various concentrations of SIFs on growth and slaughter performance, serum parameters, meat quality, and ruminal microbiota in fattening goats. After a two-week acclimation, a total of 27 5-month-old Guanzhong male goats (18.29 ± 0.44 kg) were randomly assigned to control (NC), 100 mg/d SIF (SIF1), or 200 mg/d SIF (SIF2) groups. The experimental period lasted 56 days. The weight of the large intestine was greater (p < 0.05) in the SIF1 and SIF2 groups compared with the NC group. Meat quality parameters indicated that SIF1 supplementation led to lower (p < 0.05) cooking loss and shear force (0.05 < p < 0.10). The 16S rRNA sequencing analysis demonstrated that SIF1 supplementation led to lower (p < 0.05) proportions of Papillibacter and Prevotellaceae_UCG-004 but greater (p < 0.05) CAG-352 abundance in the rumen; these responses might have contributed to the improvement in production performance. In conclusion, meat quality and ruminal microbiome could be manipulated in a positive way by oral supplementation with 100 mg/d of SIFs in fattening goats. Thus, this study provides new insights and practical evidence for the introduction of SIFs as a novel additive in goat husbandry.

Soybean isoflavone promotes milk yield and milk fat yield through the ERα-mediated Akt/mTOR pathway in dairy goats

Soybean isoflavone (SIF) in soybeans are natural phytoestrogens, which is functioned as an estrogen agonistic or antagonistic. SIF regulates the capacity of animals to synthesize triacylglycerols by directly utilizing long-chain fatty acids. However, few studies have focused on its regulatory lipid metabolism in lactating dairy goats. The objective of this study was to investigate the influence of SIF on milk yield and composition using Saanen dairy goats as a model, employing both in vivo and in vitro approaches. In the in vivo phase, a total of 20 goats were randomly divided into 2 groups: the control group fed a basal diet, and the experimental group fed a basal diet supplemented with SIF at a dosage of 100 mg/d. The results underscored a significant elevation in serum estrogen and prolactin levels in the SIF-supplemented group (P < 0.05). Notably, SIF supplementation also displayed a higher milk fat percentage (P = 0.03). Transitioning to in vitro experimentation, the addition of SIF (75 µM) to goat mammary epithelial cells exhibited a pronounced effect on cell proliferation. It spurred cell proliferation and led to an increase in triacylglycerol levels (P < 0.05). Consistently, SIF showcased an enhancement in the expression of key genes associated with milk fat de novo synthesis. SIF demonstrated a rescuing effect on the suppressive impact of MK2206 on Akt protein phosphorylation. Importantly, the study observed that the knockdown of estrogen receptor alpha (ERα) expression completely counteracted the effect of SIF on lipid droplet accumulation. Collectively, the current study establishes the critical role of SIF in process of fatty acid de novo in the goat mammary gland. This regulation is notably mediated through the ERα-Akt axis, thus enriching our understanding of this intricate biological process. This research sheds light on the potential benefits of SIF supplementation in dairy goat farming, ultimately contributing to improved milk production and quality.

Effect of Chamomile Vaginal Gel on the Sexual Function in Postmenopausal Women: A Double-Blind Randomized Controlled Trial

BACKGROUND

Female sexual dysfunction (FSD) is a common complaint among postmenopausal women, which is largely because of the genitourinary syndrome in these women (GSM).

AIM

Considering the phytoestrogenic effects of chamomile, the present study was primarily aimed to investigate the effect of chamomile vaginal gel on the sexual function of postmenopausal women. The side effects of these drugs were evaluated as a secondary outcome of the study.

METHODS

This randomized double-blind clinical trial and placebo-controlled study was conducted on postmenopausal women with sexual dysfunction (FSFI ≤26.55). To this aim, 96 postmenopausal women were randomly assigned into three groups (n = 32 each) including women receiving (i) chamomile vaginal gel 5%, (ii) conjugated estrogen vaginal cream, and (iii) placebo vaginal gel, for 12 weeks (ie, every night in the first 2 weeks, and 2 nights per week in the next 10 weeks, each night 1 g was used). The sexual function was measured using female sexual function index (FSFI) before and after the intervention. Data analysis was performed by chi-square, one-way ANOVA, descriptive statistics, analysis of covariance (ANCOVA), and paired t test using SPSS software version 22. P < .05 was considered statistically significant.

OUTCOMES

The main study outcome measure was evaluate the effects of vaginal administration of chamomile gel in comparison with conjugated estrogen cream and placebo gel on postmenopausal FSD using the FSFI.

RESULTS

The findings showed that chamomile vaginal gel in compared to placebo vaginal gel caused a significant improvement in all six sexual function domains and the total FSFI score (effect size = +2.9 [95% CI, +2.1 to +3.6], P < .001). Also, there was no significant difference between the chamomile vaginal gel and conjugated estrogen vaginal cream groups in terms of the total score and all sub-domains of sexual function with the exception of orgasm (effect size = +0.13 [95% CI, -0.36 to +0.63], P = .02) and sexual satisfaction (effect size = 0 [95% CI, -0.49 to +0.49], P = .04). Two women in the chamomile group and one in the placebo group experienced a burning sensation (P = .345).

CLINICAL IMPLICATIONS

This treatment can be considered as a treatment option for postmenopausal women with sexual dysfunction who have contraindications to the use of hormone therapy.

STRENGTHS & LIMITATIONS

This study is the first study to investigate the effectiveness of chamomile vaginal gel on sexual function in postmenopausal women. However, in this study, treatment duration was 12 weeks and no follow up was performed beyond this time CONCLUSION: Based on the results of this study, the use of vaginal chamomile gel improved sexual function in postmenopausal women. Bosak Z, Iravani M, Moghimipour E, et al. Effect of Chamomile Vaginal Gel on the Sexual Function in Postmenopausal Women: A Double-Blind Randomized Controlled Trial. J Sex Med 2022;19:983-994.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Glutamate Supply Reactivates Ovarian Function while Increases Serum Insulin and Triiodothyronine Concentrations in Criollo x Saanen-Alpine Yearlings' Goats during the Anestrous Season

The possible effect of glutamate supplementation upon ovarian reactivation and serum concentrations of insulin (INS) and triiodothyronine (T3) in anestrous yearling goats was evaluated. Goats (n = 32, 12 mo., 26° North, 1117 m) with a similar live weight (LW) and body condition score (BCS) were blood sampled twice per week for two weeks (2 × 1 week × 2 weeks) to confirm the anestrus status (<1 ng P4/mL; RIA). Thereafter, goats were randomly assigned to either 1) Glutamate (GLUT; n = 16, LW = 27.1 ± 1.09 kg, 3.5 ± 0.18 units, IV-supplemented with 7 mg of glutamate kg^-1 LW), or 2) Control (CONT; n = 16; LW = 29.2 ± 1.09 kg; BCS = 3.5 ± 0.18, IV saline). During the treatment period, 16 goats (eight/group) were blood sampled twice per week for six weeks. Such serum samples (2 × 1 week × 6 weeks) were quantified by their P4 content to evaluate the ovarian-luteal activity, whereas a sample subset (1 × 1 week × 6 weeks) was used to quantify their INS & T3 content to evaluate their metabolic status. Neither LW (28.19 kg; p > 0.05) nor BCS (3.51 units; p > 0.05) differed between treatments. Goats depicting ovarian reactivation favored the GLUT group (50 vs. 12.5%; p < 0.05). Neither INS (1.72 ± 0.15 ng mL^-1) nor T3 (2.32 ± 0.11 ng mL^-1) differed between treatments, yet a treatment x time interaction regarding INS & T3 concentration across time favored (p < 0.05) the GLUT group. The results unveil exogenous glutamate as an interesting modulator not only of ovarian reactivation, but of metabolic hormone synthesis.

Soybean isoflavone affects in rabbits: Effects on metabolism, antioxidant capacity, hormonal balance and reproductive performance

Though soybean isoflavones (SBI) have pharmaceutical properties, the compounds also have endocrine disrupting activities that may adversely affect fertility of mammals. The effects of SBI on metabolism, antioxidant capacity, hormonal balance and reproductive performance of male rabbits were investigated. Adult male rabbits (n = 21) fed an isoflavone-free diet were orally treated with 0 (control; CON), 5 (small; LSBI) or 20 (large; HSBI) mg of SBI/kg body weight/day for 12 weeks. Both SBI doses resulted in lesser blood plasma total protein concentrations, while there were no effects on glucose and cholesterol concentrations compared to CON. The HSBI-treated males had the greatest (P <  0.05) blood plasma total antioxidant capacity and least malondialdehyde. Treatment with both SBI doses induced a 43% increase in triiodothyronine concentrations (P < 0.05) and 82% in reaction times (P <  0.001), while decreased sperm concentrations (P =  0.01) and blood plasma testosterone concentrations (P =  0.017) 26% and 19%, respectively. The total functional sperm fraction was less (P <  0.05) in the HSBI group; however, there was no effect of the LSBI treatment as compared to values for the CON group. The kindling rates of females mated to HSBI-treated males tended to be less (P =  0.081) than those of does mated with LSBI or CON males. In conclusion, only the HSBI treatment improved antioxidant status; whereas, treatment with both LSBI and HSBI doses induced a hormonal imbalance which led to an impaired testis function indicating the sensitivity of the adult male reproductive system to SBI actions.

Prolonged exposure of dietary phytoestrogens on semen characteristics and reproductive performance of rabbit bucks

The effects of inclusion of different sources of dietary phytoestrogens on antioxidant capacity, hormonal balance, libido, semen quality, and fertility of rabbit bucks were studied. Twenty-one, adult, fertile, V-line bucks were randomly allocated into 3 homogenous groups (n = 7/treatment) and received control diet (phytoestrogens-free diet, CON) or soybean meal isoflavones-containing diet (SMI) or linseed meal lignans-containing diet (LML) for 12 wk. The diets were formulated to be isocaloric and isonitrogenous. The concentrations of isoflavones in the SMI diet were 24.04 mg/100 g dry matter (DM) daidzein and 13.10 mg/100 g DM genistein. The major phytoestrogen detected in the LML diet was secoisolariciresinol (36.80 mg/100 g DM). Treatment had no effects on body weight, feed intake and rectal temperature of bucks. Compared with control, bucks fed the SMI and LML diets had higher (P < 0.001) blood plasma total antioxidant capacity (0.98 ± 0.12, 1.50 ± 0.13, and 2.29 ± 0.17 mM/L for CON, SMI, and LML, respectively), and lower (P < 0.01) blood plasma malondialdehyde (2.76 ± 0.23, 1.76 ± 0.16, and 1.70 ± 0.18 nmol/mL for CON, SMI, and LML, respectively), whereas activities of reduced glutathione and superoxide dismutase (SOD) enzymes were not affected. Bucks fed the SMI and LML diets had greater (P < 0.001) concentrations of blood plasma triiodothyronine. Feeding the SMI and LML diets decreased (P < 0.01) libido (8.26 ± 0.71, 12.18 ± 0.97, and 14.12 ± 1.12 s for CON, SMI, and LML, respectively), sperm concentration (327.7 ± 21.6, 265.8 ± 36.8, and 226.5 ± 20.1 × 106/mL for CON, SMI, and LML, respectively), testosterone (5.16 ± 0.95, 3.91 ± 0.63, and 3.04 ± 0.92 ng/mL for CON, SMI, and LML, respectively), and seminal plasma fructose compared with the CON diet. The percentage of progressive motile sperm was improved (P < 0.001) by both phytoestrogen-containing diets. Feeding the SMI diet increased (P = 0.02) the percentage of live sperm compared with CON, whereas LML resulted in an intermediate value. Dietary treatment of bucks did not affect kindling rates or litter sizes of does, and did not affect birth weights or viabilities of kits. In conclusion, prolonged consumption of dietary isoflavones or lignans did not impair semen fertilizability. This may be due to the benefits of antioxidant activity or due to the benefits of other components in the diet. Dietary phytoestrogens did evoke obvious decreases in libido and steroidogenesis with altered semen parameters.

Phytoestrogens enhance the vascular actions of the endocannabinoid anandamide in mesenteric beds of female rats

In rat isolated mesenteric beds that were contracted with NA as an in vitro model of the vascular adrenergic hyperactivity that usually precedes the onset of primary hypertension, the oral administration (3 daily doses) of either 10 mg/kg genistein or 20 mg/kg daidzein potentiated the anandamide-induced reduction of contractility to NA in female but not in male rats. Oral treatment with phytoestrogens also restored the vascular effects of anandamide as well as the mesenteric content of calcitonin gene-related peptide (CGRP) that were reduced after ovariectomy. The enhancement of anandamide effects caused by phytoestrogens was prevented by the concomitant administration of the estrogen receptor antagonist fulvestrant (2.5 mg/kg, s.c., 3 daily doses). It is concluded that, in the vasculature of female rats, phytoestrogens produced an estrogen-receptor-dependent enhancement of the anandamide-vascular actions that involves the modulation of CGRP levels and appears to be relevant whenever an adrenergic hyperactivity occurs.

Effect of Ferula hermonis root extract on rat skeletal muscle adaptation to exercise

Ferula hermonis Boiss. is an aphrodisiac plant that grows in the Mediterranean region. It has been reported that treatment with acetonic extract from the root of this plant acutely increases serum testosterone in the rat. This study investigated the effects of F. hermonis extract alone or combined with exercise on rat skeletal muscle fibers. Adult male rats were divided into four groups: control-sedentary (CS) that had no treatment or exercise; ferula-sedentary (FS) that was orally treated with ferula extract at a dose of 60 mg/kg/rat every other day over a period of 20 d; control-exercised (CE) that was trained by swimming for 40 min every other day; and ferula-exercised (FE) that received ferula and performed exercise. At the end of experiments, the fiber diameter and number of muscle nuclei of tibialis anterior were measured by using immunofluorescent techniques and software analyses. The FE group showed significant increases in muscle weight, fiber size and nuclear number compared with the other groups. However, no significant changes in the aforementioned parameters were found among the CS, FS and CE groups. Ferula treatment and exercise were additive to each other. In conclusion, short-term exercise combined with administration of F. hermonis extract was more effective in enhancing the growth of skeletal muscle fibers than exercise alone.