Pivotal roles of prolactin and other hormones in lactogenesis and the nutritional composition of human milk

Codonopsis lanceolata polysaccharide ameliorates high-fat diet induced-postpartum hypogalactia via stimulating prolactin receptor-mediated Jak2/Stat5 signaling

This study aims to investigate the ameliorative effect of Codonopsis lanceolata polysaccharide (PCL) on mice with hypogalatia induced by a high-fat diet (HFD) and the potential underlying mechanism. We found that oral administration of PCL demonstrated significant benefits in countering the negative effects of HFD, including weight gain, hepatic steatosis, mesenteric adipocyte hypertrophy, and abnormal glucose/lipid metabolism. In addition, PCL improved mammary gland development and enhanced lactogenesis performance. Histologically, PCL ameliorated the retardation of ductal growth, reduced mammary fat pad thickness, improved the incomplete linear encapsulation of luminal epithelium and myoepithelium, and increased the proliferation of mammary epithelial cells. Flow cytometry analysis showed that PCL mitigated the detrimental effects of HFD on mammary gland development by promoting the proliferation and differentiation of mammary epithelial cells. Mechanistic studies revealed that PCL upregulated the levels of prolactin (PRL) and its receptor (PRLR) in the mammary gland, activated JAK2/STAT5 signaling pathway, and increased the expression of p63, ERBB4, and NRG1. Overall, PCL can ameliorate HFD-induced hypogalactia by activating PRLR-mediated JAK2/STAT5 signaling. Our findings offer a methodological and theoretical foundation for investigating the functional constituents of traditional Chinese medicine in the treatment of hypogalactia.

The effect of yoga training on postpartum prolactin and oxytocin levels in primipara women

Lactation relies on the secretion of two key hormones, prolactin and oxytocin. Studies have shown that yoga in the postpartum period can stimulate feelings of comfort and relaxation, which increases oxytocin production. The aim of this study was to evaluate the effect of yoga training on postpartum prolactin and oxytocin levels in a group of primipara women. This quasi-experimental study included 60 healthy primigravida, primipara women in their third trimester who attended antepartum and postpartum care at four primary healthcare centers in Kediri Regency. The participants were randomly allocated to an intervention group (n = 30) and a control (n = 30) group. The intervention group received health education and participated at eight yoga sessions with a duration of 60 min, from week 32 of gestation until the postpartum period. The control group received standard antepartum and postpartum care. Prolactin and oxytocin levels were measured in weeks 1 and 6 postpartum. Mean prolactin increment was significantly higher in the intervention group (176.8 ± 66.6 ng/ml) than the control group (24.8 ± 39.5 ng/ml). Similarly, mean oxytocin increment was significantly higher in the intervention group (58.6 ± 31.59 pg/ml) than the control group (14.6 ± 36.06 pg/ml). Our results suggest that yoga training in the third trimester until the postpartum period increases prolactin and oxytocin levels among primipara postpartum women.

Gene Expression Levels of CSF-1 and CSF-1R Endometrial under The Influence of Prolactin Level in Unexplained Miscarriage: A Case-Control Study

BACKGROUND

Hormones such as prolactin, by influencing expression of the endometrial genes, play a pivotal role in embryo implantation and development. The present study aimed to evaluate serum level of prolactin and its effect on altering expression level of colony-stimulating factor-1 (CSF-1) and colony-stimulating factor-1 receptor (CSF-1R) genes in endometrial tissue during in vitro fertilization (IVF) pregnancy in the infertile women and recurrent pregnancy loss (RPL), compared to fertile women, who lost their pregnancies at gestational age <20 weeks.

MATERIALS AND METHODS

In this case-control study, 40 infertile women, 40 IVF pregnant women with RPL and 40 fertile women who lost their pregnancies at <20 weeks of gestation for unknown reasons were selected. Prolactin serum level was assessed using ELISA technique and expression of CSF-1 and CSF-1R genes was determined in endometrial tissue, using quantitative reverse transcription polymerase chain reaction (qRT-PCR).

RESULTS

Mean prolactin level of the infertile group was 24.38 ± 1.43 ng/mL and it had statistically significant relationship with the fertile group (P<0.001). Expression level of the CSF-1 and CSF-1R genes were higher in the fertile than infertile groups by 2.88 times (P<0.0001) and 2.64 times (P<0.0001), while it was respectively 2.28 (P<0.0001) and 1.69 (P<0.0001) times higher compared to the RPL group. Risk factors for pregnancy loss, such as aging, increased body mass index (BMI), smoking and diabetes caused decreasing changes in gene expression (CSF-1 and CSF-1R ) and the differences were statistically significant, except in the infertile group.

CONCLUSION

The present study showed a significant relationship of CSF-1 and CSF-1R expression levels with pregnancy loss. Risk factors such as aging, obesity, smoking and diabetes decreased both genes expression levels.

Ethanol Extract of Carica papaya Leaf Can Increase Breast Milk in Lactating Rat

BACKGROUND: Carica papaya leaves (Carica papaya L) have been used empirically and traditionally as a galactogogue, but their mechanism as galactogogue is still unknown. AIM: This study aimed to analyze the effect of ethanol extract from papaya leaves on blood prolactin levels, prolactin receptor (prlr) gene expression, the number of breast alveoli and lobes of lactating rats. METHODS: This in vivo true experimental study with a post-test control group design was conducted on 24 rats with the same lactating period. They were divided into four groups consisting of six rats each. The control group was given daily standard food, whereas the three treatment groups were, respectively, given additionally ethanol extract of 0.95 mg, 1.9 mg, and 3.8 mg/200 g BW/day from day 1 to day 14 of lactation. On day 14, all of the rats were sacrificed, blood prolactin levels were measured by ELISA, prlr gene expressions were measured using RT-PCR, and numbers of breast alveoli and lobes were microscopically observed through staining histological specimens. A statistical analysis was carried out using one-way ANOVA, Tukey's test, Games–Howell test, and path analysis at 95% confidence level. RESULTS: Levels of blood prolactin levels, prlr gene expression, the number of breast alveoli, and lobes of all treatment rat groups were significantly above those of the control group (p < 0.05). The increases of all parameters were consistent; the most effective dose was 1.9 mg/200 g BW. CONCLUSION: The Carica papaya leaf ethanol extract had a galactogogue effect on lactating rats by increasing blood prolactin levels, prlr gene expression, and numbers number of breast alveoli and lobes.