ghrelin

 Foeniculum vulgare (Fennel) is one of the aromatic plants whose effect on appetite control is very questionable. we investigated the effect of fennel aqueous extract on the appetite/satiety hormones. 

Forty adult female BALB/c mice were equally divided into 5 groups; Control (no treatment), sham (distilled water injection) and FE1, FE2, FE3, the test groups (received aqueous fennel extract intraperitoneally at doses of 50, 100 and 200 (mg/kg) every 24 hours for 14 days, respectively). Serum levels of neuropeptideY (NPY), adiponectin, ghrelin and leptin were measured using ELISA. We also performed immunohistochemical staining in order to measure the hypothalamic leptin receptor expression level. Data analysis was performed by SPSS.V22. 

Serum NPY in FE3 and FE2 groups increased significantly compared with the control group (for both p<0.05). The results also showed a significant increase in serum adiponectin in FE3 group compared with the control group (p<0.05). Administration of different doses of fennel did not show any effects on ghrelin concentration. FE1 group represented the highest serum leptin concentration compared with other groups (p<0.0001). FE3 group showed a significant increase in hypothalamic leptin receptor expression level compared to the control group (p<0.05).

High doses of fennel can increase appetite, while lower doses may induce satiety. Choosing the right dose of fennel is key to using it as an effective weight management supplement.

It is well established that ghrelinerghic system has an inhibitory effect on reproductive activity. RFamide-related peptide-3 (RFRP-3) is one of the most important neuropeptides that regulates the mammalian reproduction. Studies have indicated the presence of the ghrelin receptor, called the growth hormone secretagogue receptor (GHS-R1a), in the RFRP-3 containing areas in the brain. Thus, it may be possible that ghrelinergic system involves in the control of reproduction through the RFRP-3. The aim of this study was to investigate the possible role of the GHS-R1a receptors in the regulation of RFRP-3 and its receptor GPR147 mRNA expression in the hypothalamus of male rats.

40 male Wistar rats in were divided in 8 groups (n=5) and each group received saline, 2,-4 or-8nmol ghrelin, 5,-10 or-20nmol D-Lys3-GHRP-6 (DLS), or concomitantly of ghrelin (4nmol) and DLS (10nmol) via the stereotaxically implanted cannula. Hypothalamus of rats was dissected 2h after treatment for evaluation of RFRP-3 and GPR147 mRNA levels.

Our findings indicated that 4nmol (P<0.05) or 8nmol (P<0.01) ghrelin injection significantly increased the RFRP-3 mRNA expression compare to saline group. While, the injection of 20nmol DLS significantly (P<0.05) decreased the RFRP-3-mRNA level when compared to saline group. Pretreatment of ghrelin-received animals with DLS prevented the increasing effects of ghrelin on RFRP-3 gene expression. Ghrelin or DLS had no significant effects on hypothalamic GPR147-mRNA levels.

The acute activation of GHS-R1a by gherlin has a stimulatory role in hypothalamic RFRP-3 gene expression without any significant effects on GPR147-mRNA level in an acute treatment.

Previous studies have shown that ghrelin inhibits the activity of Hypothalamus-Pituitary-Thyroid (H-P-T) axis. It is also proved that ghrelin increases the appetite via Agouti Related Protein and neuropeptide Y Pathway, decreases T3 and T4 secretion. Also morphine by effect on Pituitary hormones like TSH decreases T3 and T4 concentrations. Thus, the goal of this study was to determine the influence of the interaction between ghrelin and morphine on thyroid hormones concentration. Twenty one male Wistar rats weighing 200-250 g were randomly divided into 3 groups. The groups received 5 nmol ghrelin, 1µg morphine or 5 nmol ghrelin together with 1µg morphine in third cerebral ventricle in volumes of 3 μl .The blood samples were collected every day. Starting one day before and up to one day after injections. Brain slices were taken to ensure that the place of the canulae was right. The plasma was analysed by Radioimmunoassay technique to determine T3 and T4 concentrations. The results showed that the i.c.v injection of ghrelin and morphine significantly decreased the mean plasma concentrations of thyroid hormones (P<0.05). Co-administration of these two substances in some of groups showed that decrease mean plasma concentrations of thyroid hormones (P<0.05). This study showed that ghrelin and morphine significantly decreased mean plasma concentration of T3 and T4. Co-administration of two substances in some of groups showed that decrease mean plasma concentration of thyroid hormones (p<0.05).

Rehabilitation training in cardiac patients after coronary artery bypass graft (CABG) improves several physiological capacities. The aim of this study was to investigate the effect of eight weeks of combined training on plasma levels and ghrelin gene expression in PBMNC among CABG patients. In this quasi-experimental study, 30 cardiac patients of Javad Al-Aemeh cardiac specialty hospital of Mashhad, who underwent CABG operation, were selected using convenience and purposeful sampling method and randomly divided into two equal groups (n=15): combined training and control. The combined training group performed selected aerobic and resistance training protocols for eight weeks, three sessions per week. Before and after training program, body composition assessments and blood sampling were performed to measure variables. Then, the obtained data were analyzed using independent and dependent t-tests at the significance level of 0.05. Data analysis showed that combined training significantly reduces body weight and BMI and significantly increases plasma ghrelin levels and relative expression of ghrelin gene in PBMNC (P≤0.05). Additionally, a significant difference was observed between plasma ghrelin levels and relative expression of ghrelin gene in PBMNC of training group compared to control group (P≤0.05). It seems that eight weeks of combined rehabilitation training increases plasma levels and ghrelin gene expression in PBMNC among CABG patients and can promote desirable physiological adaptations in cardiovascular health.

Ghrelin increases food intakes and body weight while weight loss and fasting is accompanied by increased levels of cortisol. The goal of this study was to determine the effects of cortisol and morphine on ghrelin concentration in ewes with different levels of energy requirements.Ten Zandi ewes were randomly divided in to two groups. The groups were fed either by 50% or 100% of energy content in diet for 10 days. After a week animals in both groups received cortisol(60 μg/kg), morphine(0. 15 mg/kg) or simultaneous injection of cortisol and morphine respectively. Blood samples were collected 2 hours after infusions.Ghrelin concentration significantly increased in the 7th day of experiment compared to first day in the %50 group. While in the group by 100% energy level, significant changes wasn’t observed in ghrelin concentration. After injection of cortisol ghrelin reduction in the both groups. Morphine increased ghrelin in both groups. After simultaneous injection of cortisol and morphine there was no significant increasing and decreasing changes in both groups.