It is widely recognized that developing bi- or multifunctional opioid compounds could offer a valuable approach to pain management with fewer side effects compared to single-target compounds. In this study, we designed and characterized two novel chimeric peptides, EM-1-DLS and EM-2-DLS, incorporating endomorphins (EMs) and the ghrelin receptor antagonist [D-Lys3]-GHRP-6 (DLS). Functional assays demonstrated that EM-1-DLS and EM-2-DLS acted as κ-opioid receptor (κ-OR)-preferring agonists, weak μ-opioid receptors (μ-OR) and ghrelin receptor (GHSR) agonists. Upon intracerebroventricular (i.c.v.) administration in mice, both EM-1-DLS and EM-2-DLS exhibited dose- and time-dependent antinociceptive effects in the tail withdrawal test. EM-1-DLS demonstrated the highest antinociceptive potency among the peptides, with an ED50 approximately 8-fold greater than EM-1, while EM-2-DLS showed comparable effects to EM-2. The antinociceptive actions of EM-1-DLS involved activation of GHS-R1α, μ-OR, and κ-OR, whereas EM-2-DLS acted via GHS-R1α, δ-OR, and κ-OR pathways. Additionally, acute antinociceptive tolerance was investigated, revealing that EM-1-DLS induced a tolerance ratio of 2.33-fold, significantly lower than the 5.19-fold ratio induced by EM-1. Cross-tolerance ratios between the chimeric peptides and EMs ranged from 0.92 to 1.76, indicating reduced tolerance compared to EMs alone. These findings highlight the potential of these chimeric peptides to mitigate pain with diminished tolerance development, suggesting a promising strategy for the development of new analgesic therapies with improved safety profiles.

This study aimed to evaluate the cardioprotective effects of ghrelin in septic mice, focusing on its anti-inflammatory and antioxidant properties. Thirty-five male Swiss mice (8-12 weeks old, 23-33g) were randomly assigned to five groups (n = 7 each): (1) Normal, fed usual diets, (2) Sham, subjected to anesthesia and laparotomy, (3) Sepsis, subjected to cecal ligation and puncture, (4) Vehicle, given an equivalent volume of intraperitoneal saline injections immediately after cecal ligation and puncture, and (5) Ghrelin-treated, administered 80 µg/kg ghrelin intraperitoneal injections immediately following cecal ligation and puncture. Serum levels of tumor necrosis factor-alpha (TNF-α), macrophage migration inhibitory factor (MIF), toll-like receptor 4 (TLR4), and 8-epi-prostaglandin F2 alpha (8-epi-PGF2α) were measured. The extent of cardiac damage was also evaluated histologically. The mean serum levels of TNF-α, MIF, TLR4, and 8-epi-PGF2α levels were significantly higher in the sepsis and vehicle groups than in the normal and sham groups. The levels were significantly lower in the ghrelin-treated group than in the vehicle and sepsis groups. Histological analysis revealed normal myocardial architecture in the normal and sham groups, whereas the sepsis and vehicle groups had severe myocardial injury. The ghrelin-treated group displayed histological features similar to the sham group, indicating reduced myocardial damage. Ghrelin ameliorated sepsis-induced cardiotoxicity in mice by exhibiting strong anti-inflammatory and antioxidant effects. These findings suggest that ghrelin may be a promising therapeutic candidate for the prevention of sepsis-induced cardiotoxicity.

BACKGROUND: Thyroid storm (TS), a life-threatening condition that can damage multiple organs, has limited therapeutic options. Hypercytokinemia is a suggested background, but the pathological condition is unclear and there are no appropriate animal models. We aimed to develop a TS mouse model by administration of triiodothyronine and lipopolysaccharide, and then to examine the effects of ghrelin on this model.
METHODS: We evaluated the use of serum IL-6 levels as a representative marker of hypercytokinemia in patients with TS. To establish the mouse model, preliminary experiments were conducted to determine the non-lethal doses of triiodothyronine and lipopolysaccharide when administered individually. As a TS model, C57BL/6 mice were administered with triiodothyronine 1.0 mg/kg (subcutaneously, once daily for seven consecutive days) and lipopolysaccharide 0.5 mg/kg (intraperitoneally, on day 7) to develop a lethal model with approximately 30% survival on day 8. We assessed the survival ratio, mouse sepsis scores and blood biomarkers (IL-6, metanephrine, alanine aminotransferase) and evaluated the effects of ghrelin 300 µg/kg on these parameters in TS model.
RESULTS: Serum IL-6 was increased in patients with TS compared with those with Graves\' disease as the diseased control (18.2 vs. 2.85 pg/mL, P < .05, n = 4 each). The dosage for the murine TS model was triiodothyronine 1.0 mg/kg and lipopolysaccharide 0.5 mg/kg. The TS model group had increased mouse sepsis score, serum IL-6, metanephrine and alanine aminotransferase. In this model, the ghrelin improved the survival rate to 66.7% (P < .01, vs. 0% [saline-treated group]) as well as the mouse sepsis score, and it decreased the serum IL-6 and metanephrine.
CONCLUSIONS: We established an animal model of TS that exhibits pathophysiological states similar to human TS with induction of serum IL-6 and other biomarkers by administration of T3 and LPS. The results suggest the potential effectiveness of ghrelin for TS in humans.

Ghrelin modulates several biological functions via selective activation of the growth hormone secretagogue receptor (GHSR). GHSR agonists may be useful for the treatment of anorexia and cachexia, while antagonists and inverse agonists may represent new drugs for the treatment of metabolic and substance use disorders. Thus, the identification and pharmacodynamic characterization of new GHSR ligands is of high interest. In the present work the label-free dynamic mass redistribution (DMR) assay has been used to evaluate the pharmacological activity of a panel of GHSR ligands. This includes the endogenous peptides ghrelin, desacyl-ghrelin and LEAP2(1-14). Among synthetic compounds, the agonists anamorelin and HM01, the antagonists HM04 and YIL-781, and the inverse agonist PF-05190457 have been tested, together with HM03, R011, and H1498 from patent literature. The DMR results have been compared to those obtained in parallel experiments with the calcium mobilization assay. Ghrelin, anamorelin, HM01, and HM03 behaved as potent full GHSR agonists. YIL-781 behaved as a partial GHSR agonist and R011 as antagonist in both the assays. LEAP2(1-14) resulted a GHSR inverse agonist in DMR but not in calcium mobilization assay. PF-05190457, HM04, and H1498 behaved as GHSR inverse agonists in DMR experiments, while they acted as antagonists in calcium mobilization studies. In conclusion, this study provided a systematic pharmacodynamic characterization of several GHSR ligands in two different pharmacological assays. It demonstrated that the DMR assay can be successfully used particularly to discriminate between antagonists and inverse agonists. This study may be useful for the selection of the most appropriate compounds to be used in future studies.

Exercise training is a valuable tool for improving body weight and composition in overweight or obese adults, which leads to a negative energy balance. It is relevant to consider whether exercise can help people lose weight or prevent weight gain because any energy expended in exercise increases the severity of hunger and promotes food consumption. Over the past decade, the identification of the circulating peptide ghrelin, which alerts the brain to the body\'s nutritional state, has significantly expanded our understanding of this homeostatic mechanism that controls appetite and body weight. To shed more light on this issue, we decided to investigate the effects of resistance and endurance training on plasma ghrelin and leptin levels. In addition, we sought to understand the mechanisms by which acute and chronic exercise can regulate hunger. This review analyzes studies published in the last fifteen years that focused on changes suffered by ghrelin, leptin, or both after physical exercise in overweight or obese individuals. Most studies have shown a decrease in leptin levels and an increase in ghrelin levels in these cases. Exercise regimens that support weight maintenance need further investigation.

The growing drive towards more sustainable dietary patterns has led to an increased demand for and availability of plant-based meat analogues (PBMAs). This systematic review aims to summarize the currently available evidence from human intervention studies investigating the impact of substituting animal meat (AM) with PBMAs in adults. A total of 19 studies were included. Overall, an increase in satiety following PBMA intake was reported, albeit to different extents and not always accompanied by changes in leptin and ghrelin. PBMAs generally resulted in lower protein bioavailability and a smaller increase in plasma essential amino acids in comparison to AM. However, muscle protein synthesis and physical performance were not affected. Finally, conflicting results have been reported for other outcomes, such as pancreatic and gastrointestinal hormones, oxidative stress and inflammation, vascular function, and microbiota composition. In conclusion, we documented that the impact of substituting AM with PBMA products has been scarcely investigated. In addition, the heterogeneity found in terms of study design, population, outcomes, and findings suggests the need for additional high-quality intervention trials, particularly long-term ones, to better clarify the advantages and potential critical issues of such substitutions within sustainable healthy diets.

Objective. Genetic factors substantially contribute to the development and duration of arterial hypertension. The study of the A1166C polymorphism of the angiotensin II type 1 receptor gene (AGTR1) in arterial hypertension is an auspicious area for assessing the relationship between heredity, hypertension development, and adipokines, but it still remains debatable. The purpose of the current study was to investigate serum adipokines levels depending on the AGTR1 A1166C polymorphism. Methods. A total of 86 patients with arterial hypertension were examined, who underwent the evaluation of the allelic A1166C polymorphism of AGTR1 by polymerase chain reaction with electrophoretic detection and determination of serum adipokines levels using enzyme-linked immunosorbent assay. Results. In the group of patients with arterial hypertension, a significant increase in serum adipokines (resistin, adiponectin, and leptin) levels was found against the background of a decrease in the antianorexic hormone ghrelin with a predominance of CC genotype carriers compared with AA genotype carriers of the AGTR1. A statistically significant decrease in ghrelin and an increase in serum adipokines (resistin, adiponectin, and leptin) in CC genotype carriers compared with AA genotype carriers of the AGTR1 were found suggesting that CC genotype carriers may be predictors of the development of arterial hypertension in our patients. Conclusions. Statistically significant decrease in ghrelin and increase in serum adipokines (resistin, adiponectin, and leptin) were found in CC genotype carriers compared with AA genotype carriers of the AGTR1, which suggests that carriers of the CC genotype are predictors of the arterial hypertension development in our patients.

Ingestible electronics have the capacity to transform our ability to effectively diagnose and potentially treat a broad set of conditions. Current applications could be significantly enhanced by addressing poor electrode-tissue contact, lack of navigation, short dwell time, and limited battery life. Here we report the development of an ingestible, battery-free, and tissue-adhering robotic interface (IngRI) for non-invasive and chronic electrostimulation of the gut, which addresses challenges associated with contact, navigation, retention, and powering (C-N-R-P) faced by existing ingestibles. We show that near-field inductive coupling operating near 13.56 MHz was sufficient to power and modulate the IngRI to deliver therapeutically relevant electrostimulation, which can be further enhanced by a bio-inspired, hydrogel-enabled adhesive interface. In swine models, we demonstrated the electrical interaction of IngRI with the gastric mucosa by recording conductive signaling from the subcutaneous space. We further observed changes in plasma ghrelin levels, the \"hunger hormone,\" while IngRI was activated in vivo, demonstrating its clinical potential in regulating appetite and treating other endocrine conditions. The results of this study suggest that concepts inspired by soft and wireless skin-interfacing electronic devices can be applied to ingestible electronics with potential clinical applications for evaluating and treating gastrointestinal conditions.

OBJECTIVE: This study aimed to investigate the integrative effects and mechanisms of transcutaneous electrical acustimulation (TEA) on postprocedural recovery from endoscopic retrograde cholangio-pancreatography (ERCP).
METHODS: A total of 86 patients for elective ERCP were randomly ordered to receive TEA (n = 43) at acupoints PC6 and ST36 or Sham-TEA (n = 43) at sham points from 24 hours before ERCP (pre-ERCP) to 24 hours after ERCP (PE24). Scores of gastrointestinal (GI) motility-related symptoms and abdominal pain, gastric slow waves, and autonomic functions were recorded through the spectral analysis of heart rate variability; meanwhile, circulatory levels of inflammation cytokines of tumor necrosis factor-α (TNF-α) and interleukin (IL)-10 and GI hormones of motilin, ghrelin, cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) were assessed by enzyme-linked immunosorbent assay.
RESULTS: 1) TEA, but not Sham-TEA, decreased the post-ERCP GI motility-related symptom score (2.4 ± 2.6 vs 7.9 ± 4.6, p < 0.001) and abdominal pain score (0.5 ± 0.7 vs 4.1 ± 2.7, p < 0.001) at PE24, and decreased the post-ERCP hospital day by 20.0% (p ＜0.05 vs Sham-TEA); 2) TEA improved the average gastric percentage of normal slow waves and dominant frequency by 34.6% and 33.3% at PE24, respectively (both p < 0.001 vs Sham-TEA); 3) TEA, but not Sham-TEA, reversed the ERCP-induced increase of TNF-α but not IL-10 at PE24, reflected as a significantly lower level of TNF-α in the TEA group than in the Sham-TEA group (1.6 ± 0.5 pg/mL vs 2.1 ± 0.9 pg/mL, p ＜ 0.01); 4) compared with Sham-TEA, TEA increased vagal activity by 37.5% (p ＜ 0.001); and 5) TEA caused a significantly higher plasma level of ghrelin (1.5 ± 0.8 ng/ml vs 1.1 ± 0.7 ng/ml, p ＜ 0.05) but not motilin, VIP, or CCK than did Sham-TEA at PE24.
CONCLUSIONS: TEA at PC6 and ST36 accelerates the post-ERCP recovery, reflected as the improvement in GI motility and amelioration of abdominal pain, and suppression of the inflammatory cytokine TNF-α may mediate through both autonomic and ghrelin-related mechanisms.

BACKGROUND: Diabetes mellitus (DM) presents impediment to wound healing. While ultraviolet B (UVB) exposure showed therapeutic potential in various skin conditions, its capacity to mediate diabetic wound healing remains unclear. To investigate the efficacy of UVB on wound healing and its underlying basis.
METHODS: Male C57BL/6 mice were subjected to the high-fat diet followed by streptozotocin administration to establish the diabetic model. Upon confirmation of diabetes, full-thickness wounds were inflicted and the treatment group received UVB radiation at 50 mJ/cm2 for 5 min every alternate day for 2 weeks. Wound healing rate was then assessed, accompanied by evaluations of blood glucose, lipid profiles, CD31 expression, and concentrations of ghrelin and leptin. Concurrently, in vitro studies were executed to evaluate the protective role of ghrelin on human umbilical vein endothelial cells (HUVEC) under high glucose (HG) conditions.
RESULTS: Post UVB exposure, there was a marked acceleration in wound healing in DM mice without alterations in hyperglycemia and lipid profiles. Compared to non-UVB-exposed mice, the UVB group showed enhanced angiogenesis manifested by a surge in CD31 expression. This trend appeared to be in harmony with the elevated ghrelin levels. In vitro experiments indicated that ghrelin significantly enhanced the migratory pace and angiogenic properties of HUVEC under HG-induced stress, potentially mediated by an upregulation in vascular endothelial growth factor expression.
CONCLUSIONS: UVB exposure bolstered wound healing in diabetic mice, plausibly mediated through augmented angiogenesis induced by ghrelin secretion. Such findings underscore the vast potential of UVB-induced ghrelin in therapeutic strategies targeting diabetic wound healing.