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

Polyphenols in Farm Animals: Source of Reproductive Gain or Waste?

“…In traditional farming systems, Glycine max (soybean: [ 44 , 45 ]), Linum usitatissimum (linseed [ 44 ]), and clover species such as T. subterraneum [ 14 ], T. pratense L. (red clover [ 11 , 18 ]), and Trifolium alexandrinum (Berseem clover: [ 13 ]) are the most common sources of polyphenols in animal diets. Due to the limitation of traditional animal feed resources, many feed alternatives such as shrubs and trees are being introduced as new feedstuff.…”

“…Summary of recent in vivo studies on the effects of polyphenols on the reproductive performance of males and females of farm animals is shown in Table 2 and Table 3 . In brief, these studies address that farm animals consuming diets based on seeds and/or forage with polyphenolic compounds of isoflavones and lignans (phytoestrogens) evidence substantial reproductive disturbances in sexual activity, hormonal balance and gonads function ( T. pratense L., red clover, silage: [ 11 ]; T. alexandrinum , berseem clover: [ 13 , 59 ]; Glycine max, soybean, or Linum usitatissimum linseed-based diets: [ 44 , 45 ]; linseed: [ 57 ]), which mask any positive effects on antioxidant activity and redox homeostasis [ 44 , 45 ]. These negative effects on reproductive performance are caused by the hormone-like effects, either acting as estrogen agonist and/or antagonist, of the polyphenolic compounds known as phytoestrogens (flavonoids, lignans, and stilbenes).…”

“…These data support the usefulness and relative safety of tanniferous plants (shrubs and trees), if properly consumed, for improving reproductive performance of animals ( Yucca schidigera : [ 73 ]; Quebracho tannins: [ 12 , 74 ]). On the other hand, caution should be paid when breeding animals are fed phytoestrogenic polyphenols-rich (flavonoids, nonflavonoids, and phenolic acids) plants such as soybean, linseed, clover, milk thistle seeds, rosemary leaves [ 67 ], soybean isoflavones supplement [ 45 ], and green tea powder [ 5 ]. Indeed, bioavailability of tannins seems to be more restricted due to their high molecular weight and weaker absorption through the intestine, which may limit their effects [ 75 ].…”

“…Consumption of the shrub Sesbania sesban L. exerts a negative effect on the expression of behavioral estrus in sheep [ 77 ] and feeding T. alexandrinum L. isoflavones (212,076.2 μg/ewe/day rich in biochanin A) also prevents or shortens behavioral estrus in sheep [ 13 , 58 ]. Similarly, feeding a linseed-based diet (containing primarily secoisolariciresinol and daidzein), soybean-based diet (containing mainly genistein and daidzein) or soybean isoflavones (containing a ratio of 1 genistein: 5.7 daidzein) have been found to decrease libido of rabbit bucks [ 44 , 45 ]. Conversely, Mustonen et al [ 11 ] reported that feeding sheep with T. pratense L. silage (containing formononetin, biochanin A, genistein, and daidzein) for a total of 5 months did not affect mean numbers of estrus per pregnancy (2.1 ± 0.7 for the T. pratense L. vs. 2.2 ± 0.8 grass silage in controls).…”

>b<Estudos >i<in vivo>/i< e >i<in vitro>/i< da influência da ivermectina na produção de testosterona e na atividade antitumoral em linhagem celular de melanoma>/b<

“…A administração da dose terapêutica de ivermectina foi incapaz de alterar os níveis séricos de testosterona em ratos até 72 h após a administração de ivermectina e, em coelhos, até o 30º dia da administração. A concentração sérica de ivermectina, em ratos, foi similar entre os dois grupos experimenais (0,2 e 1,0 mg/mL) e o teste Two-way ANOVA não mostrou diferenças significantes entre os grupos tratados em relação ao grupo controle em ambas espécies.Os níveis de testosterona medidos neste experimento são similares àqueles relatados por outros autores(OZCAN et al, 2015;HWANG et al, 2016;ABO-ELSOUD et al, 2019). Por outro lado, El-Far (2013), utilizando a dose de 0,5 mg/kg de ivermectina, em coelhos, observou aumento significativo LDH, CPK, estresse oxidativo, bem como aumento dos níveis de testosterona.…”