Effect of Flaxseed on some hormonal profile and genomic DNA concentration in Karadi lambs

Abstract

The aims of the current study were to investigate the effect of dietary supplementation of flaxseed powder on some hormonal profile and genomic DNA concentration of Karadi male lambs. Twelve healthy Karadi ram lambs, 6 months old, were randomly divided into 3 equal groups (4 lambs/group); and the treatments were as follow for two months; 0% considered as control group, 4% as a low level (T1), and 8% of flaxseed as a high level (T2) in their feed. Blood samples were collected from each ram lambs every two weeks, serum was separated immediately after sampling, testosterone, estradiol, growth hormone (GH), Thyroid Stimulating Hormone (TSH), and Thyroxine (T4) were measured. Genomic DNA was extracted from each samples. The results showed that testosterone hormone concentration decreased significantly in T2 group (1.575±0.004 n.mol / l) in comparison to control group (6.95±1.992 n.mol / l). Estradiol hormone level significantly increased in T1 (293±4.2 P.mol/l) in comparison to control and T2 (128.5±5.485 and 139±8.083 P.mol/l) respectively. A positive significant effect of flaxseed recorded on growth hormone, which its level increased in T2 group (120±2 ng/ul) in comparison to T1 group (81.5±1 ng/ul). TSH concentration increased significantly in T1 and T2 groups (13.5±2 and 14.5±1 U/ml, respectively) in comparison to control group (7±1.5 U/ml), while T4 hormone was not affected. Flaxseed supplementation caused a significant decrease in Genomic DNA concentration in T2 group (56.2 ng) in comparison to control (28.7 ng). In conclusion, adding flaxseed in lamb rations caused a significant decrease of testosterone, increased estradiol concentration, also each of growth hormone and TSH hormones increased significantly, T4 not affected. This decrease in genomic DNA concentration with flaxseed supplementation may due to one of the mechanisms by which phytoestrogens may influence reproductive physiology that involve in inhibition of enzymes essential for DNA replication.

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

“…The bioactivity of polyphenols depends moreover on several factors including the polyphenol molecular weight, its conjugation with other derivatives, its hydrolysation by digestive tract enzymes (stomach and intestine), the action of rumen or cecal microflora, and the binding affinity for blood plasma proteins [ 57 ].…”

“…Polyphenols may also control steroid function by binding or inactivating sex production enzymes, such as P450 aromatase, 5α-reductase, 17β-hydroxysteroid dehydrogenase (17β-OHDH), topoisomerases, and tyrosine kinases. In addition, polyphones can alter sex hormone binding globulin (SHBG) affinity, and thus levels of active steroids in blood circulation [ 57 ]. Finally, polyphenols can also affect the reproductive functions through controlling the expression of genes or the activity of enzymes that contribute to the regulation of reproductive events: (1) activity of enzymes controlling DNA replication (topoisomerases I and II) and extracellular signal regulated kinases; (2) antioxidant and inflammatory molecular pathways; (3) cellular apoptotic and proliferation pathways; (4) modification of the expression of genes related to synthesis of angiogenesis factors in different reproductive tissue; (5) epigenetic mechanisms involving both hypermethylation and hypomethylation; (6) regulation of metabolic hormone signals such as growth hormones, insulin-like growth factors, and triiodothyronine; and (7) modification of the expression of genes associated with fatty acids metabolism [ 13 , 55 , 57 , 64 , 65 ].…”

“…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).…”

“…homadae ) can inhibit the activity of the steroid 5α-reductase by binding to the enzyme [ 83 ]. Isoflavones, stilbenes, and coumestans can inhibit 5α-reductase, aromatase and the 3β-hydroxysteroid dehydrogenase/isomerase complex by decreasing gene expression and/or inhibiting the enzyme itself [ 57 , 84 ]. In other studies, gossypol inhibits activity of 5α-reductase and 3α-hydroxysteroid dehydrogenase enzymes [ 85 ], as well as the antioxidant enzyme superoxide dismutase, via the second messenger cGMP pathway, leading to inhibition of steroid production by different molecular pathways [ 85 ].…”

Effect of Dietary Flaxseed Oil Supplementation on the Redox Status, Haematological and Biochemical Parameters of Horses’ Blood

“…The presence of these compounds acting as estrogens may disrupt the metabolism of sex hormones in males and negatively affect reproductive indices. This was evidenced by the results of studies where flaxseeds were used, and not FO [33,34]. It should be mentioned that lignans are weak estrogens [35] and as mentioned earlier, their content in oil is much lower than in seeds, which minimizes the risk of adverse effects.…”