سیده تقوا موسوی

Estrogen consumption in women can increase the risk of breast cancer. Estrogen stimulates the growth of cancer cells through the estrogen receptor alpha (ERα). One of the strategies that has recently been considered is the use of phytoestrogens. Previous studies have shown that Chaste-berry contains high levels of phytoestrogens. Scientists disagree on whether the phytoestrogens in Chaste-berry are used to treat many diseases in women, which are ERα or ERβ selective. In the present study, laying hens were used as a model to find the answer because only alpha estrogen receptor is expressed in the oviduct. In this study, the effect of Chaste-berry fruit powder on performance, egg quality, immune response, and the expression of GnRH, LH, ovalbumin (OVAL), and ovomucoid (OVM) genes in laying hens were evaluated. A total of 90 leghorns (Hy-Line, W-36) laying hens (at 72 to 80 weeks old) were used in a completely randomized design with three treatments and five replicates (n=6). The treatments were various levels of Chaste-berry fruit powder including zero, 1, and 2% levels of Chaste-berry fruit powder per kg of diet. Our results showed that performance parameters, egg quality factors, and immune responses were not significantly affected by various levels of Chaste-berry fruit powder. Moreover, the results indicated that the various levels of Chaste-berry did not have a significant effect on LH, OVAL, and OVM gene expression. However, GnRH gene expression was significantly increased in treatment 3 (a diet containing 2% Chaste-berry) compared to the control and 1% Chaste-berry groups. Moreover, the addition of 1% Chaste-berry fruit powder to the diet had no significant effect on GnRH gene expression. Therefore, Chaste-berry supplementation is not recommended in laying hens. Furthermore, our data reinforce this theory that phytoestrogens in Chaste-berry fruits are ERβ-selective.

Phytoestrogens are herbal estrogens with estrogen-like functions and structures. The estrogen hormone has an important role in the process of the synthesis of egg white proteins in the avian oviduct. Vitex agnus-castus (VAC) is a native plant of the middle Asian, southern European, and Mediterranean countries. This plant has numerous uses in traditional medicine and is traditionally used to treat many diseases in women. Previous studies have shown that VAC contains high levels of phytoestrogens. VAC consists of compounds such as vitexin, apigenin, and pendoltin, which are the most active phytoestrogen in VAC fruits. No study has been published so far on the effect of VAC on oviduct markers gene expression (ovalbumin (OVAL) and ovomucoid (OVM)). Hence, this study was performed to evaluate the effect of VAC fruits on gene expression for two oviduct markers OVAL and OVM of laying hens.

A total of 90 leghorns (Hy-Line, W-36) laying hens on the second cycle of production (at 72 to 80 weeks old) were used in a completely randomized design with three treatments, five replicates and six hens per replivate. The treatments were various levels of VAC fruit powder including zero, 1, and 2% levels of VAC fruit powder per kg of diet. After extraction of total RNA, RNA quality was evaluated using Nanodrop and agarose gel electrophoresis and cDNA was synthesized using a Sinaclone kit. Eventually, gene expression was measured by the real-time qPCR method. In this method, 𝜷-actin gene was used as a reference gene to normalize the gene expression data. To confirm the specificity of each primer, its melting curves were examined.

Electrophoresis of the PCR products showed the 60, 133, and 150-bp fragments for OVAL, OVM, and Beta-actin, respectively. Melting peaks analysis on the PCR products for all primers confirmed minimal primer-dimers and primer specificity. The results of the real-time qPCR method indicated that supplementation of VAC fruits powder at levels 1 and 2 to the diet of laying hens has no effect on the expression of OVAL and OVM genes of laying hens in the second production cycle.

Therefore, Adding VAC fruit powder to the diet of laying hens is not expected to increase egg production in laying hens. Therefore, VAC supplementation is not recommended to the diet of laying hens.