Browse more peptide research, methods and limitations.
Whey protein produced greater short-term satiety than casein in humans, with faster amino acid absorption, higher plasma amino acid peaks, and different gastrointestinal hormone (CCK, GLP-1) profiles.
Hall, W L; Millward, D J; Long, S J; Morgan, L M · Clinical Trial
The thymosin family comprises functionally distinct members: prothymosin alpha (gene regulation), thymosin alpha-1 (immune modulation), parathymosin (chromatin), and beta-thymosins (cytoskeleton/wound healing) — each with unique therapeutic potential.
Hannappel, Ewald; Huff, Thomas · Review
Multiple neuropeptide systems (CRF, NPY, substance P/NK1, galanin, vasopressin, nociceptin) offer novel antidepressant and anxiolytic targets with mechanisms fundamentally different from monoamine-based drugs.
Holmes, Andrew; Heilig, Markus; Rupniak, Nadia M J; Steckler, Thomas; Griebel, Guy · Review
Ghrelin's unique status as the only circulating appetite-promoting hormone, combined with evidence from knockout and antibody studies, makes it a rational anti-obesity drug target for reducing hunger and fat accumulation.
Horvath, Tamas L; Castañeda, Tamara; Tang-Christensen, Mads; Pagotto, Uberto; Tschöp, Matthias H · Review
A novel Na+/Cl--coupled opioid peptide transport system was identified in retinal pigment epithelial cells, enabling active regulation of local opioid peptide concentrations at the blood-retinal barrier.
Hu, Huankai; Miyauchi, Seiji; Bridges, Christy C; Smith, Sylvia B; Ganapathy, Vadivel · In Vitro
A structure-based macrocyclic peptide deformylase inhibitor showed potent enzyme inhibition with a novel antibiotic mechanism targeting an essential bacterial enzyme absent in humans.
Hu, Xubo; Nguyen, Kiet T; Verlinde, Christophe L M J; Hol, Wim G J; Pei, Dehua · In Vitro
Dynorphin-positive nerve fibers were found in close apposition to lymphocytes in the rat liver, providing anatomical evidence for direct opioidergic neuroimmunomodulation of hepatic immune responses.
Kaiser, Matthias J T; Tiegs, Gisa; Neuhuber, Winfried L · Animal Study
Mu-opioid receptor agonists inhibited basal and LH-stimulated progesterone and androstenedione production in porcine theca cells in a dose-dependent manner, demonstrating direct opioid peptide control of ovarian steroidogenesis.
Kaminski, T; Siawrys, G; Bogacka, I; Okrasa, S; Przala, J · In Vitro
Epithalon peptide (Ala-Glu-Asp-Gly) induced telomerase catalytic subunit (hTERT) expression, telomerase enzymatic activity, and telomere elongation in telomerase-negative human fetal fibroblasts.
Khavinson, V Kh; Bondarev, I E; Butyugov, A A · In Vitro
In a 6-8 year follow-up study of 266 elderly people, treatment with thymic peptide (Thymalin) and pineal peptide (Epithalamin) bioregulators for 2-3 years was associated with dramatic reductions in mortality: 2.0-2.1 times lower with Thymalin, 1.6-1.8 times lower with Epithalamin, and 2.5 times lower with the combination. The most striking result: patients treated with both peptides annually for 6 years showed a 4.1-fold decrease in mortality compared to controls. Treated patients also showed improved cardiovascular, endocrine, immune, and nervous system function, a 2.0-2.4 fold reduction in respiratory infections, and lower rates of ischemic heart disease, hypertension, osteoarthritis, and osteoporosis.
Khavinson, Vladimir Kh; Morozov, Vyacheslav G · Clinical Trial
Plasma ET-1 correlated with NYHA class, exercise capacity, and BNP in CHF patients, and independently predicted adverse outcomes, providing complementary prognostic information to natriuretic peptides.
Kinugawa, Toru; Kato, Masahiko; Ogino, Kazuhide; Osaki, Shuichi; Igawa, Osamu; Hisatome, Ichiro; Shigemasa, Chiaki · Cross Sectional
Selank and tuftsin-family peptides improved adaptive behavior in stressed animals in a phenotype-dependent manner, with different peptides optimal for different emotional reactivity types — supporting personalized peptide anxiolytic therapy.
Kozlovskaya, M M; Kozlovskii, I I; Val'dman, E A; Seredenin, S B · Animal Study
Selank selectively enhanced conditioned avoidance learning and memory in rats with initially low learning ability while minimally affecting normal learners, demonstrating deficit-correcting rather than general cognitive enhancement.
Kozlovskii, I I; Danchev, N D · Animal Study
GH secretagogues primarily activated arcuate nucleus neurons while NPY activated both arcuate and ventromedial hypothalamic neurons, demonstrating distinct appetite-stimulating circuits despite similar feeding outcomes.
Kumarnsit, Ekkasit; Johnstone, Louise E; Leng, Gareth · Animal Study
Opioid peptides directly inhibited uterine cell proliferation in a developmental stage-dependent manner: strongest in immature tissue, diminishing with maturation, with different receptor subtypes active at different stages.
Környei, J L; Vértes, Z; Kovács, K A; Göcze, P M; Vértes, M · In Vitro
A macrocyclic peptide incorporating beta-aminophosphotyrosyl mimetic achieved potent Grb2 SH2 domain binding through conformational restriction, demonstrating macrocyclic drug design for cancer signaling disruption.
Lee, Kyeong; Zhang, Manchao; Liu, Hongpeng; Yang, Dajun; Burke, Terrence R · In Vitro
TNF-alpha inhibited TFF3 transcription through NF-κB activation in intestinal cells, creating a pathogenic feedback loop where inflammation simultaneously damages the gut AND suppresses its natural repair peptide.
Loncar, M B; Al-azzeh, E-d; Sommer, P S M; Marinovic, M; Schmehl, K; Kruschewski, M; Blin, N; Stohwasser, R; Gött, P; Kayademir, T · In Vitro
POMC-derived beta-endorphin selectively modulated the appetitive (wanting/seeking) phase of feeding behavior in a deprivation-state-dependent manner, separating opioid reward from hunger-driven consumption.
Low, Malcolm J; Hayward, Michael D; Appleyard, Suzanne M; Rubinstein, Marcelo · Animal Study
Alpha-MSH and KPV serve triple immune functions: anti-inflammatory (NF-κB inhibition, cytokine suppression), antimicrobial (direct pathogen killing), and immunomodulatory (melanocortin receptor-mediated immune cell regulation) — a comprehensive immune regulatory system.
Luger, Thomas A; Scholzen, Thomas E; Brzoska, Thomas; Böhm, Markus · Review
Early inflammatory pain inhibition was mediated by CRF-triggered opioid release from immune cells, while late inflammation used chemokine (CXCL1/2)-stimulated opioid release — the intrinsic pain control mechanism evolves with inflammation maturation.
Machelska, Halina; Schopohl, Julia K; Mousa, Shaaban A; Labuz, Dominika; Schäfer, Michael; Stein, Christoph · Animal Study
High hydrostatic pressure sensitized Salmonella typhimurium and Pseudomonas aeruginosa outer-membrane mutants to lactoferrin, lactoferricin, and other antimicrobial peptides through outer membrane disruption.
Masschalck, Barbara; Deckers, Daphne; Michiels, Chris W · In Vitro
Chronic oral GHRP-2 in GH-deficient adults produced persistent increases in appetite and body weight alongside GH/IGF-1 elevation, confirming sustained orexigenic effects of long-term GH secretagogue therapy.
Mericq, Verónica; Cassorla, Fernando; Bowers, Cyril Y; Avila, Alejandra; Gonen, Boas; Merriam, George R · Clinical Trial
PT-141 (bremelanotide) induced sexual arousal in both male and female animals through central MC3R/MC4R activation, representing a mechanistically novel approach to sexual dysfunction treatment through brain desire pathways rather than peripheral blood flow.
Molinoff, P B; Shadiack, A M; Earle, D; Diamond, L E; Quon, C Y · Animal Study
Ghrelin provides triple-mechanism benefit for heart failure: GH-mediated cardiac improvement, appetite stimulation counteracting cachexia, and direct GHS-R-mediated cardioprotection — addressing three core disease components.
Nagaya, Noritoshi; Kangawa, Kenji · Review
Ghrelin treatment improved LVEF, increased lean body mass, enhanced exercise capacity, and reduced neurohormonal activation in heart failure, simultaneously addressing cardiac dysfunction and cachexia.
Nagaya, Noritoshi; Kangawa, Kenji · Review
GH secretagogues directly modulated skeletal muscle electrical excitability and contractile properties through a muscle-specific ghrelin-type receptor, independent of GH release — revealing direct muscle-targeting activity.
Pierno, Sabata; De Luca, Annamaria; Desaphy, Jean-François; Fraysse, Bodvael; Liantonio, Antonella; Didonna, Maria Paola; Lograno, Marcello; Cocchi, Daniela; Smith, Roy G; Camerino, Diana Conte · In Vitro
Both short and long maternal separation produced distinct, persistent alterations in brain opioid peptide levels (dynorphin, met-enkephalin) across reward and stress regions in adult rats, demonstrating lasting neurochemical consequences of early life experience.
Ploj, Karolina; Roman, Erika; Nylander, Ingrid · Animal Study
In healthy human colon and ileum tissue, LL-37 expression was restricted to differentiated epithelial cells. In cell culture, butyrate, isobutyrate, propionate, and the histone deacetylase inhibitor trichostatin A all increased LL-37 expression in colon cells alongside cell differentiation. Flavone also induced LL-37 but without affecting differentiation, demonstrating that LL-37 can be upregulated independently. Critically, when the MEK-ERK signaling pathway was blocked, butyrate-induced LL-37 expression was abolished — even though cell differentiation was actually enhanced. Conversely, blocking the p38/MAP kinase pathway stopped cell differentiation without inhibiting LL-37 expression. This separation of signaling pathways means LL-37 production and cell maturation are independently controllable, opening the possibility of specifically boosting antimicrobial peptide production through targeted dietary or pharmacological interventions.
Schauber, J; Svanholm, C; Termén, S; Iffland, K; Menzel, T; Scheppach, W; Melcher, R; Agerberth, B; Lührs, H; Gudmundsson, G H ·
CP-154,526 showed anxiolytic effects across multiple animal models, antidepressant activity, and HPA axis modulation without sedation, providing the most comprehensive validation of CRF1 antagonism as a psychiatric drug mechanism.
Seymour, Patricia A; Schmidt, Anne W; Schulz, David W · Review
Topical BPC-157 cream reversed methylprednisolone-induced burn wound healing impairment in mice, restoring wound closure rates during concurrent steroid treatment.
Sikiric, P; Seiwerth, S; Mise, S; Staresinic, M; Bedekovic, V; Zarkovic, N; Borovic, S; Gjurasin, M; Boban-Blagaic, A; Batelja, L; Rucman, R; Anic, T · Animal Study
Multiple peptidase inhibition in rat spinal cord slices allowed endogenous opioid peptides to accumulate and trigger mu-opioid receptor internalization, revealing that rapid enzymatic degradation normally prevents full endogenous opioid receptor activation.
Song, Bingbing; Marvizón, Juan Carlos G · In Vitro
BPC-157 accelerated transected Achilles tendon healing in rats (improved biomechanics and histology) and directly stimulated tendocyte proliferation in vitro, demonstrating both functional repair and cellular mechanism.
Staresinic, M; Sebecic, B; Patrlj, L; Jadrijevic, S; Suknaic, S; Perovic, D; Aralica, G; Zarkovic, N; Borovic, S; Srdjak, M; Hajdarevic, K; Kopljar, M; Batelja, L; Boban-Blagaic, A; Turcic, I; Anic, T; Seiwerth, S; Sikiric, P · Animal Study
Depression, panic, and PTSD show distinct stress neurohormone patterns (CRF, vasopressin, NPY alterations), with ANP demonstrating anxiolytic properties — disorder-specific peptide profiles enabling targeted therapy.
Ströhle, A; Holsboer, F · Review
MK-677 treatment increased the proportion of non-22kDa and 20kDa GH isoforms relative to total GH in obese subjects, demonstrating that GH secretagogues alter the GH isoform profile differently from exogenous GH replacement.
Svensson, J; Boguszewski, C L; Shibata, F; Carlsson, B; Carlsson, L M S; Bengtsson, B-A · Clinical Trial
Intrathecal [Dmt1]DALDA analgesia was partly mediated by endogenous opioid peptide release (confirmed by opioid antiserum blocking), demonstrating drug-induced amplification through the endogenous opioid system.
Szeto, Hazel H; Soong, Yi; Wu, Dunli; Qian, XuanXuan; Zhao, Guo-Min · Animal Study
All three endogenous opioid peptide families (endorphins, enkephalins, dynorphins) inversely correlated with aggression across brain regions, with each acting through distinct receptor systems (mu, delta, kappa) and neural circuits.
Tordjman, Sylvie; Carlier, Michèle; Cohen, David; Cesselin, François; Bourgoin, Sylvie; Colas-Linhart, Nicole; Petiet, Anne; Perez-Diaz, Fernando; Hamon, Michel; Roubertoux, Pierre L · Animal Study
Beta-casomorphin-7 and casein hydrolysate stimulated mucus release in rat jejunum through mu-opioid receptor activation, providing a direct mechanism for dairy-derived gut protection through opioid peptide signaling.
Trompette, Aurélien; Claustre, Jean; Caillon, Fabienne; Jourdan, Gérard; Chayvialle, Jean Alain; Plaisancié, Pascale · Animal Study
Dynorphin B activated nuclear opioid receptors coupling to nuclear PKC activation, which induced cardiac transcription factors (GATA-4, Nkx-2.5) for cardiogenesis in embryonic stem cells — a novel nuclear signaling mechanism.
Ventura, Carlo; Zinellu, Elisabetta; Maninchedda, Emiliana; Maioli, Margherita · In Vitro
Opioid-primed cardiogenesis in GTR1 embryonic stem cells was mediated by PKC epsilon nuclear translocation, which activated GATA-4 and Nkx-2.5 cardiac transcription — mapping the complete opioid-to-cardiac differentiation signaling cascade.
Ventura, Carlo; Zinellu, Elisabetta; Maninchedda, Emiliana; Fadda, Marina; Maioli, Margherita · In Vitro
Lactoferricin demonstrates antibacterial, antifungal, antiviral, antiparasitic, antitumor, and immunomodulatory activities — establishing it as a remarkably multi-functional peptide derived from the common milk protein lactoferrin.
Wakabayashi, H; Takase, M; Tomita, M · Review
Peripheral opioid receptor activation in airway mucosa increased net water absorption, affecting mucociliary transport — identifying an opioidergic regulation of tracheobronchial respiratory defense mechanisms.
Wang, Lian; Tiniakov, Ruslan L; Yeates, Donovan B · Animal Study
Serial postoperative BNP levels predicted clinical complications and recovery trajectory after CABG, with persistent elevation identifying high-risk patients, while ANP was less discriminating.
Watanabe, Masazumi; Egi, Koso; Hasegawa, Satoru; Tanaka, Hiroyuki; Ohshima, Hisanaga; Sakamoto, Tohru; Sunamori, Makoto · Cohort
Intravenous ghrelin administration increased slow-wave sleep (deep sleep) across the total night and enhanced delta-wave activity during the second half of the night. REM sleep was reduced during the second third of the night, while other sleep stages were unaffected. Ghrelin also stimulated multiple hormonal responses: growth hormone and prolactin levels were elevated throughout the night, and cortisol rose during the first half. Interestingly, the GH response was strongest after the first injection and weakest after the fourth, while cortisol showed the opposite pattern. Leptin levels were unaffected.
Weikel, J C; Wichniak, A; Ising, M; Brunner, H; Friess, E; Held, K; Mathias, S; Schmid, D A; Uhr, M; Steiger, A · Clinical Trial
High-dose intrathecal endomorphin-2 produced anti-analgesia through spinal dynorphin release activating NMDA receptors, demonstrating a dose-dependent flip from opioid analgesia to opioid-induced pain generation.
Wu, Hsiang-En; Sun, Han-Sen; Darpolar, Moses; Leitermann, Randy J; Kampine, John P; Tseng, Leon F · Animal Study
Met-enkephalin (OGF) inhibited cancer proliferation through OGFr nuclear translocation and activation of p16/p21 cell cycle inhibitors across pancreatic, colon, and squamous cell cancers — a non-classical opioid anti-cancer mechanism.
Zagon, Ian S; McLaughlin, Patricia J · In Vitro
Adrenomedullin is overexpressed in many cancers where it promotes tumor growth, drives angiogenesis (tumor blood vessel formation), and may suppress anti-tumor immunity — positioning it as a multi-mechanism cancer therapy target.
Zudaire, E; Martínez, A; Cuttitta, F · Review
Cecropin A, melittin, magainin, and indolicidin demonstrated antiviral activity against both Junin virus (arenavirus) and HSV-1, expanding the antimicrobial peptide antiviral spectrum to include hemorrhagic fever viruses.
Albiol Matanic, Vanesa C; Castilla, Viviana · In Vitro
Thymosin alpha-1 + interferon-alpha achieved 40% SVR versus 20% for interferon alone in naive chronic hepatitis C patients (n=22), demonstrating significant immune-mediated enhancement of antiviral efficacy.
Andreone, P; Gramenzi, A; Cursaro, C; Felline, F; Loggi, E; D'Errico, A; Spinosa, M; Lorenzini, S; Biselli, M; Bernardi, M · RCT
Cyclic peptides targeting CDK2's substrate recruitment site (not catalytic site) selectively induced tumor cell apoptosis through the E2F pathway, with crystal structures confirming the novel binding mechanism.
Andrews, Martin J I; McInnes, Campbell; Kontopidis, George; Innes, Lorraine; Cowan, Angela; Plater, Andy; Fischer, Peter M · In Vitro
MK-677 increased GH and IGF-1 in elderly hip fracture patients with functional improvement trends, but the primary endpoint of functional independence was not statistically significant in this pilot RCT.
Bach, Mark A; Rockwood, Kenneth; Zetterberg, Carl; Thamsborg, Gorm; Hébert, Réjean; Devogelaer, Jean-Pierre; Christiansen, Jens Sandahl; Rizzoli, René; Ochsner, J Lockwood; Beisaw, Norman; Gluck, Oscar; Yu, Leisure; Schwab, Thomas; Farrington, Jeanne; Taylor, Alice M; Ng, Jennifer; Fuh, Vivian · RCT