Animal only
This study characterized growth hormone (GH) secretion patterns and responsiveness to exogenous GH-releasing hormone (GHRH) in adult male cynomolgus monkeys, with the goal of evaluating their suitability as a model for pituitary toxicity research. Two groups of ten animals were used to assess diurnal and day-to-day GH variation via serial serum sampling, while a separate four-animal-per-group crossover examined GH responses to intravenous pralmorelin hydrochloride (a GHRH analog) versus saline. GH was measured by ELISA. The study found a diurnal pattern resembling that of humans, with GH rising in the late morning, dipping around midday, and peaking at night. Considerable inter- and intra-individual daily variation was also observed over five consecutive days. In the stimulation test, GHRH-treated animals showed significantly higher GH concentrations at 0.5 and 1 hour post-administration compared to controls. The authors conclude that cynomolgus monkeys share key GH secretion characteristics with humans and may serve as a relevant non-clinical model. Limitations include small sample sizes, male-only subjects, and the non-human primate setting, meaning direct translation to human physiology or clinical applications requires caution.
In vivo (Athens, Greece) · Jan 2026DOI ↗ Animal only
This study developed a novel low-temperature fabrication method for soluble microneedles (MNs) loaded with thymosin β4 (Tβ4), a peptide with known wound-healing and immunomodulatory properties. Traditional MN production methods involve conditions that can denature sensitive peptides, so the researchers used chitosan and sucrose to create stable, biocompatible MNs at lower temperatures. The resulting patches demonstrated uniform morphology, a high drug-loading capacity (~248 µg/patch), and rapid dissolution within one hour. In a mouse wound model, Tβ4-loaded MNs significantly enhanced wound healing compared to controls. To investigate the underlying mechanism, the study employed RNA sequencing and differentially expressed gene (DEG) analysis, identifying downregulated immune regulators Spp1, Vsig4, and IL22rα2 as potentially relevant targets. Subsequent in vitro experiments — including qPCR, western blot, and surface plasmon resonance (SPR) — demonstrated that Tβ4 specifically binds to Vsig4 (KD = 3.56 × 10⁻⁶ M) and IL22rα2 (KD = 9.69 × 10⁻⁶ M). A key limitation is that efficacy and mechanistic data are primarily derived from mouse models and cell-based assays, with no human clinical data reported. The findings offer insights into Tβ4's immunomodulatory targets and potential avenues for drug development.
Advanced healthcare materials · Dec 2025DOI ↗ Animal only
This study introduced a Golgi-targeted copper delivery system (LNP-ATOX1/GHK-Cu@PCL-GelMA) designed to enhance the activity of copper-dependent proteins—particularly lysyl oxidase (LOX)—to promote fascia regeneration. The system combined GHK-Cu (a copper-peptide complex) as a sustained-release copper source with lipid nanoparticles (LNPs) delivering mRNA encoding ATOX1, a copper chaperone that shuttles copper into the Golgi apparatus via ATP7A/B transporters. In vitro experiments showed the system significantly increased Golgi copper accumulation, raised LOX activity to approximately 1.78 times that of controls, and enhanced angiogenic capacity. The researchers also reported that ATOX1 upregulation promoted copper-dependent translocation of ATP7A and Rac1 to the plasma membrane, potentially supporting neovascularization. In a rabbit fascia defect animal model, the strategy improved collagen alignment, neovascularization, and extracellular matrix reconstruction. Limitations include the absence of human or large-animal data, reliance on a single animal model, and the translational gap between rabbit fascia repair and human clinical outcomes. No human trials were conducted.
Journal of controlled release : official journal of the Controlled Release Society · Dec 2025DOI ↗ Animal only
This study investigated the central effects of Liver-Expressed Antimicrobial Peptide 2 (LEAP-2) on food intake in broiler chickens, and explored its potential interactions with the ghrelin and cannabinoid systems. Four separate experiments were conducted, each with four groups of neonatal broiler chickens receiving intracerebroventricular (ICV) injections. Experiment 1 tested LEAP-2 alone at three doses; Experiments 2–4 tested LEAP-2 in combination with a ghrelin receptor antagonist (D-Lys-3)-GHRP-6, a CB1 receptor antagonist (SR141716A), and a CB2 receptor antagonist (AM630), respectively. Food consumption was measured at 30, 60, and 120 minutes post-injection. The study reported that ICV LEAP-2 at the two higher doses significantly reduced cumulative food intake compared to saline controls. The interaction experiments suggested that LEAP-2's appetite-suppressing effects may involve both CB1 and CB2 cannabinoid receptors as well as the ghrelin receptor system. Key limitations include the exclusive use of an avian (broiler chicken) model, small experimental group sizes, a single-species focus, and the lack of direct mechanistic or molecular data. Findings cannot be directly extrapolated to humans or mammals without further research.
Poultry science · Dec 2025DOI ↗ Animal only
This study investigated whether a self-assembling Growth Hormone-Releasing Peptide-6 (GHRP-6) peptide hydrogel could improve outcomes in acute kidney injury (AKI) by targeting metabolic reprogramming in renal tubular epithelial cells (TECs). Using a mouse model of AKI (likely ischemia-reperfusion injury), the researchers administered the GHRP-6 hydrogel and performed metabolomic sequencing analysis to characterize changes in cellular metabolism. The study found that treatment was associated with elevated levels of spermidine, L-glutamine, and acetyl-CoA — metabolites linked to amino acid and fatty acid metabolism — suggesting a favorable metabolic shift in TECs. Further mechanistic experiments indicated that the GHRP-6 hydrogel promoted TEC survival under ischemic conditions by activating the mTOR-P70 signaling pathway. The authors conclude that GHRP-6 hydrogel may protect TECs and reduce the risk of post-AKI fibrosis through metabolic reprogramming. Key limitations include that findings are restricted to a mouse model with no human data, the sample sizes and controls are not detailed in the abstract, and translation to clinical settings remains undemonstrated. The novel hydrogel formulation adds a materials-science dimension but also introduces additional variables requiring further study.
Journal of nanobiotechnology · Dec 2025DOI ↗ Animal only
This preclinical study characterizes SLU-PP-915, a novel orally bioavailable pan-agonist of estrogen receptor-related receptors (ERRα, ERRβ, and ERRγ) — orphan nuclear receptors that regulate mitochondrial biogenesis, oxidative phosphorylation, fatty acid oxidation, and the Krebs cycle. The researchers compared SLU-PP-915 to a previously developed ERR pan-agonist, SLU-PP-332, which lacks oral bioavailability. In mouse models, both compounds similarly enhanced aerobic exercise performance (measured by running distance and duration) when administered intraperitoneally, and SLU-PP-915 maintained comparable efficacy via oral administration when adjusted for systemic exposure. Both compounds strongly induced expression of Ddit4, a gene upregulated by acute aerobic exercise, at levels matching or exceeding those produced by treadmill running, depending on the muscle group examined. Notably, SLU-PP-915 appeared to synergize with exercise training to further enhance Ddit4 and mitochondrial gene expression. The authors propose that orally active ERR agonists could have therapeutic relevance for metabolic disorders, cardiovascular disease, and muscle pathologies. Key limitations include exclusive use of animal models, with no human data reported, and the need for long-term safety and efficacy evaluation.
The Journal of pharmacology and experimental therapeutics · Dec 2025DOI ↗ Animal only
This paper introduces a novel conceptual framework called the "triad" — linking corneal ulcer healing, corneal neovascularization, and intraocular pressure — and extends it to avascular tissue healing, using tendon as a parallel model. The authors propose cytoprotection as a unifying therapeutic principle and use the stable gastric pentadecapeptide BPC 157 as a primary illustrative agent. Drawing on preclinical studies, the paper describes findings in which BPC 157 reportedly normalized elevated intraocular pressure in glaucomatous rats, preserved retinal integrity, restored pupil function, maintained corneal transparency during ulcer or abrasion healing, and counteracted corneal neovascularization and dry eye. The paper also systematically maps a broad range of existing standard therapeutic agents — including ascorbate, fibronectin, EGF, anti-VEGF agents, corticosteroids, prostaglandin analogs, and Rho-kinase inhibitors — onto this triad to highlight shared pathways and inconsistencies across drug classes. The work is framed as a theoretical and narrative synthesis of preclinical data rather than a new clinical trial, and the authors explicitly call for further translational research before clinical application. Key limitations include the absence of human trial data and reliance on animal models.
Pharmaceuticals (Basel, Switzerland) · Nov 2025DOI ↗ Animal only
This study investigated whether milk-derived small extracellular vesicles (sEVs) could serve as oral delivery vehicles for two GLP-1 receptor agonists (GLP-1RAs): semaglutide and tirzepatide. Researchers loaded both peptides onto sEVs in vitro and administered them orally to diabetic db/db mice—a well-established mouse model of type 2 diabetes. The study found that both peptides were efficiently incorporated into the sEV carrier system and that oral administration of the loaded vesicles effectively reduced blood glucose levels in the diabetic mice. The authors compared this approach to the existing SNAC (sodium N-[8-(2-hydroxybenzoyl) amino] caprylate) technology used in the commercially approved oral semaglutide formulation (Rybelsus), arguing that sEVs offer broader applicability across multiple peptide drugs, not just semaglutide. Key limitations include the exclusive use of an animal model with no human pharmacokinetic or efficacy data, a relatively small and homogeneous study design, and the early-stage, preclinical nature of the platform. Translation to humans remains undemonstrated.
Journal of extracellular biology · Nov 2025DOI ↗ Animal only
This mouse study examined how acute restraint stress (30 minutes) interferes with hunger-driven food-seeking behavior and what interventions can reverse this effect. Using a conflict-based open-field feeding paradigm, researchers found that restraint stress abolished the increases in food seeking and intake normally observed in fasted mice. Two pharmacological interventions — intraperitoneal diazepam (an anxiolytic) and MK-677 (a ghrelin receptor agonist) — both reversed this stress-induced suppression of feeding behavior, though through apparently distinct neural mechanisms. To map neural correlates, the study measured c-Fos (a marker of neuronal activation) and phosphorylated pyruvate dehydrogenase (pPDH, a marker of neuronal inhibition) in the paraventricular hypothalamic nucleus (PVN). Diazepam reduced restraint-induced c-Fos expression in the PVN, suggesting anxiolysis works via suppressing stress-driven PVN activation, while MK-677 increased pPDH, indicating a separate feeding-drive mechanism. Notably, refeeding after fasting produced a pPDH-dominant PVN pattern and also reduced anxiety-related behaviors, suggesting physiological restoration of energy balance may itself confer stress resilience. Key limitations include exclusive use of a mouse model, the use of a single stress paradigm, and the lack of direct causal circuit manipulations. Findings are not directly applicable to humans without further study.
Neuroscience research · Nov 2025DOI ↗ Animal only
This study describes the development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method for measuring tirzepatide — a dual GIP/GLP-1 receptor agonist — in rat plasma. Researchers used protein precipitation with methanol for sample preparation, a peptide C18 column for chromatographic separation, and positive electrospray ionization with multiple reaction monitoring for detection, using semaglutide as an internal standard. The method demonstrated good linearity (1–1000 ng/mL), with intra- and inter-day accuracy and precision meeting regulatory criteria. Stability under various storage and handling conditions was also confirmed. The validated method was then applied to a pharmacokinetic study in rats administered tirzepatide intravenously and subcutaneously at 0.3 mg/kg. The study reports terminal half-lives of approximately 10 hours via both routes and estimates subcutaneous bioavailability at roughly 62%. Key limitations include the exclusive use of a rat model, a single dose level, and a small number of animals typical of preclinical PK studies, meaning findings may not translate directly to humans. The authors suggest the method could be adapted for quantifying other structurally similar peptide therapeutics.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences · Oct 2025DOI ↗ Animal only
This study investigated the role of ferroptosis (a form of iron-dependent regulated cell death) in pulpitis and evaluated whether thymosin α1 (Tα1) could mitigate this process. Using single-cell RNA sequencing (scRNA-seq) of tissue from 3 pulpitis and 3 healthy pulp samples, researchers identified 12 distinct cell clusters and found that differentially expressed ferroptosis-related genes (DE-FRGs) were broadly present across clusters in pulpitis tissue. Elevated reactive oxygen species (ROS) and Fe²⁺ levels, alongside reduced GPX4 and elevated PTGS2 expression by immunohistochemistry, suggested active ferroptosis in inflamed pulp. In LPS-stimulated dental pulp cells (DPCs) in vitro, Tα1 treatment was associated with increased GPX4 and FTL expression and reduced inflammatory markers (TNF-α, IL-1β, IL-6) and Fe²⁺ levels. In rat pulpitis models, delivery of prothymosin α (PTMA, the Tα1 precursor) via gelatin sponge or direct injection reduced inflammatory cell infiltration, decreased PTGS2, and increased GPX4. RNA sequencing of LPS-stimulated DPCs confirmed reversal of DE-FRG expression with Tα1 treatment. Key limitations include small human tissue sample sizes (n=3 per group), reliance on animal and cell models for intervention data, and the lack of human clinical trials.
International journal of oral science · Oct 2025DOI ↗ Animal only
This paper is a commentary responding to a previously published literature and patent review by Józwiak et al. (Pharmaceuticals 2025) that raised concerns about BPC 157, a stable synthetic gastric pentadecapeptide. The authors defend BPC 157's therapeutic profile, arguing that the reviewed concerns — specifically that it promotes pathological angiogenesis, elevates nitric oxide (NO) and eNOS toward damaging free radical formation, and may contribute to tumorigenesis or neurodegenerative diseases — are speculative and contradicted by existing preclinical evidence. The authors frame BPC 157 as a cytoprotective agent rooted in Robert's and Szabo's cytoprotection concept, emphasizing its alleged pleiotropic effects across organ systems. They argue that BPC 157 modulates rather than indiscriminately amplifies angiogenesis and the NO system, citing animal model studies on wound healing, corneal transparency, anti-tumor effects (per Folkman's concept), and counteraction of Parkinson's- and Alzheimer's-like disturbances in mice and rats. The paper reports a high safety profile (LD50 not achieved in animal studies). Key limitations include that this is a narrative commentary relying heavily on preclinical data, with no new human clinical trial data presented and no controlled experimental methodology introduced.
Pharmaceuticals (Basel, Switzerland) · Sep 2025DOI ↗ Animal only
This preclinical study developed a dual-crosslinked injectable hydrogel (HSMP-LA) designed to mimic natural gut mucus for treating colitis. The hydrogel combined thiol/maleimide-modified hyaluronic acid with two active agents: antimicrobial ε-polylysine (ε-PL) and larazotide acetate (LA), a tight junction–regulating peptide. In laboratory (in vitro) experiments using LPS-injured Caco-2 intestinal cells, sustained release of LA was reported to selectively inhibit zonulin-mediated tight junction disruption by targeting the MLCK/p-MLC signaling pathway, thereby restoring epithelial barrier integrity. The hydrogel also demonstrated broad-spectrum antimicrobial activity and strong mucoadhesive properties with prolonged retention. In a dextran sodium sulfate (DSS)-induced mouse model of colitis, HSMP-LA significantly reduced disease activity indices, suppressed pro-inflammatory cytokines, upregulated anti-inflammatory IL-10, repaired tight junction proteins (ZO-1, occludin, claudin-5), restored mucus production (MUC2), and rebalanced gut microbiota composition. The study's primary limitations are that all findings are confined to cell culture and animal models, with no human data reported. The dual-action strategy—simultaneously targeting barrier dysfunction and microbial imbalance—represents the authors' proposed innovation, though clinical translation remains undemonstrated.
Journal of controlled release : official journal of the Controlled Release Society · Sep 2025DOI ↗ Animal only
This study developed a biodegradable buccal suction patch designed to improve the systemic delivery of peptide therapeutics by bypassing gastrointestinal degradation. Researchers replaced previously used non-degradable silicone materials with thermally crosslinked, synthesized copolyesters, fabricated via a scalable mold-casting process. Mechanical testing across multiple polymer formulations and patch shapes identified the best-performing biodegradable candidate, and degradation was confirmed in both aqueous media and simulated waste environments. An ex vivo model using porcine buccal tissue demonstrated that the biodegradable patch, when combined with a chemical permeation enhancer, improved permeation of a poorly permeable dye compared to controls. In an in vivo study conducted in beagle dogs, the patch substantially improved the bioavailability of semaglutide (4.11 kDa) relative to a commercially available oral tablet over a 10-minute application window. Additionally, the patch achieved a relative bioavailability of approximately 26% for bremelanotide (1.03 kDa) compared to subcutaneous injection. Limitations include the use of an animal model (beagle dogs) rather than human subjects, a small experimental scale, and the need for further clinical translation studies. The work highlights a potential sustainable alternative to silicone-based buccal delivery devices.
Journal of Controlled Release · Aug 2025
Animal only
This study investigated whether dietary supplementation with GHRP-6, a synthetic ghrelin analog peptide, could modulate endocrine and immune responses in gilthead seabream (Sparus aurata), a commercially important aquaculture species. Fish were fed diets containing GHRP-6 for 97 days and then challenged with Incomplete Freund's Adjuvant (IFA), an immune stimulant, via intraperitoneal injection. Samples were collected 72 hours post-injection. The study found that GHRP-6-fed fish maintained more stable plasma levels of lactate, triglycerides, and cortisol following IFA challenge compared to control fish, suggesting reduced metabolic stress. Circulating immunoglobulin levels were significantly elevated in the GHRP-6/IFA group, indicating enhanced humoral immunity. Transcriptomic analysis showed the anterior intestine was the most responsive tissue, with upregulation of immune-related genes including il10, il15, il34, and mx1. Spleen tissue showed increased expression of il8, il10, and ighm, suggesting a balanced inflammatory response. No histological damage was observed in the intestine or spleen. Limitations include the exclusive use of a single fish species, no mammalian or human data, a single GHRP-6 dietary concentration tested, and the authors themselves characterize results as "preliminary."
Animal only
This preclinical study investigated whether three GLP-1-based receptor agonists — semaglutide (GLP-1 receptor agonist), tirzepatide (dual GLP-1/GIP receptor agonist), and retatrutide (triple GIP/GLP-1/glucagon receptor agonist) — could alter the interoceptive (subjective-like) effects of alcohol in rats. Using an operant drug discrimination paradigm in both male and female rats, researchers trained animals to distinguish alcohol from vehicle, then tested whether these compounds disrupted that learned discrimination. The study found that acute administration of all three agents attenuated alcohol's discriminative stimulus effects, suggesting modulation of how alcohol "feels" internally. Repeated semaglutide treatment maintained this effect over a 15-day period, and the effect reversed within three days of cessation. The authors suggest these findings may help explain clinically observed reductions in alcohol craving and drinking in humans receiving GLP-1 receptor agonists. Limitations include the exclusive use of animal models, meaning direct translation to human subjective alcohol experience remains uncertain, and the study does not assess long-term outcomes or dependence-related endpoints.
Psychopharmacology · Jul 2025DOI ↗ Animal only
This controlled animal trial investigated the comparative effects of three butyrate-based dietary supplements — tributyrin with copper and essential oils (TB-500), di- and tri-butyrin (TB-300), and coated sodium butyrate (SB-500) — versus a control diet in 1,000 Arbor Acres broiler chicks across four treatment groups (250 birds each, six replicates). Over 35 days, researchers measured growth performance, carcass traits, serum biochemistry, immune markers, gene expression (mTOR, TLR4, NBN), intestinal histomorphometry, caecal microbiota, and litter hygiene. The study found that TB-300 was associated with improved body weight (+4.6%), feed conversion ratio (–5.2%), and European Production Efficiency Factor (+14.9%). SB-500 was linked to reduced litter Clostridia and aerobic bacterial counts. All butyrate treatments were associated with improved intestinal villus morphology, elevated serum total proteins and digestive enzymes (lipase and protease), and upregulated TLR4 gene expression. TB-300 and SB-500 were associated with reduced serum lipids, urea, and AST, alongside enhanced mTOR and NBN gene expression. Limitations include that the study was conducted exclusively in broiler chickens, findings are not directly translatable to humans, and it did not include a blinded assessment of outcomes.
Scientific reports · Jul 2025DOI ↗ Animal only
This study investigated the mechanisms underlying weight loss produced by CagriSema — a combination of cagrilintide (an amylin analogue) and semaglutide (a GLP-1 analogue) — in a rat model. Researchers quantified the contributions of reduced energy intake versus preserved energy expenditure to overall weight loss. Rats treated with CagriSema achieved approximately 12% body weight loss alongside a 39% reduction in food intake. To isolate the role of energy intake, the authors used two comparison conditions: pair-feeding (matching food intake to CagriSema-treated animals) and weight matching (determining how much food restriction alone would be needed to achieve equivalent weight loss, which required a 51% reduction in intake). The gap between these conditions suggested that roughly one-third of CagriSema's weight loss effect was attributable to blunting of metabolic adaptation — the phenomenon where the body typically reduces energy expenditure in response to caloric restriction. Limitations include that findings are from an animal model and may not directly translate to humans, and the study does not address long-term outcomes. The authors conclude that CagriSema's dual action on both energy intake and expenditure may contribute to its potential effectiveness as an obesity treatment.
Nature metabolism · Jul 2025DOI ↗ Animal only
This study investigated the therapeutic potential of GHK-Cu (glycyl-l-histidyl-l-lysine-copper) in ulcerative colitis (UC) using a dextran sulfate sodium (DSS)-induced mouse model and complementary cell-based experiments. Researchers administered GHK-Cu to BALB/c mice with DSS-induced colitis and assessed disease activity, colon histology, goblet cell counts, tight junction proteins (ZO-1, Occludin), inflammatory cytokines (TNF-α, IL-6, IL-1β), and key signaling proteins (SIRT1, STAT3, p-STAT3, RORγt). Network pharmacology and molecular docking were used to predict SIRT1 as a core target. A co-culture model of mouse colonic epithelial cells (MCECs) and peritoneal macrophages confirmed GHK-Cu's role in mucosal healing. STAT3 silencing via siRNA revealed that STAT3 is required for GHK-Cu's promotion of epithelial healing and tight junction protein upregulation, but not for its anti-inflammatory effects, suggesting additional pathways are involved. The study found that GHK-Cu reduced disease severity, suppressed inflammation, enhanced mucosal repair via the SIRT1/STAT3 pathway, and decreased RORγt expression, suggesting reduced Th17 cell activity. Limitations include exclusive use of animal and in vitro models with no human data.
Frontiers in pharmacology · Jul 2025DOI ↗ Animal only
This review paper examines the proposed therapeutic mechanisms and safety profile of BPC 157, a synthetic 15-amino-acid peptide derived from a gastric protein. The authors argue, drawing on Robert and Szabo's cytoprotection concept, that BPC 157's protective effects on gastric epithelial and endothelial cells extend to other organ systems (cytoprotection → organoprotection). The paper addresses and disputes concerns that BPC 157 might promote tumorigenesis through angiogenesis, generate harmful free radicals via increased nitric oxide (NO) and eNOS activity, or contribute to neurodegenerative diseases such as Parkinson's and Alzheimer's. Instead, the authors contend that, based on reviewed animal and in vitro studies, BPC 157 modulates angiogenesis in a context-dependent manner—maintaining corneal transparency and opposing pathological neovascularization—while demonstrating anti-tumor effects both in vivo and in vitro per Folkman's framework. The paper also reports that BPC 157 counteracts Parkinson's- and Alzheimer's-like disturbances in rodent models and modulates NO levels without promoting damaging free radical formation. Key limitations include the heavy reliance on animal and in vitro data, the absence of human clinical trial data, and the authors' advocacy framing.
Pharmaceuticals (Basel, Switzerland) · Jun 2025DOI ↗