Melanotan 1 (MT1)
The Skin Protector
Protect Your Skin: Enhance UV Resistance with Melanotan 1
Melanotan 1 (MT1), also known as afamelanotide, is a synthetic peptide primarily used for its ability to stimulate the production of melanin, the pigment responsible for skin color. This peptide is a synthetic analog of the naturally occurring hormone α-melanocyte-stimulating hormone (α-MSH), which plays a crucial role in regulating skin pigmentation.
Melanotan 1 works by binding to and activating the melanocortin 1 receptor (MC1R) on the surface of melanocytes, the cells in the skin that produce melanin. By activating this receptor, Melanotan 1 mimics the natural signaling pathways that lead to an increase in melanin production. The resulting effect is a darker skin tone, which can provide a protective layer against UV radiation from the sun.
This peptide has been explored for its potential therapeutic benefits, particularly in providing a protective tan that could reduce the risk of skin damage and potentially lower the incidence of skin cancers in individuals with fair skin who are more susceptible to UV rays.
Potential Benefits Under Research
- Enhanced UV Protection: Increases melanin in the skin, providing a protective tan that can reduce the risk of sunburn and subsequent UV radiation damage.
- Prevention of Skin Cancers: The increased pigmentation might lower the risk of various skin cancers, particularly in lighter-skinned individuals more vulnerable to UV damage.
- Treatment of Skin Disorders: Potential treatment for conditions responsive to increased melanin, such as erythropoietic protoporphyria (EPP), a condition where sunlight can cause painful skin reactions.
- Photoprotection in Photosensitive Conditions: May help manage photosensitivity in conditions like polymorphous light eruption, which results in rashes and other skin reactions from sunlight exposure.
- Possible Reduction in Blood Pressure: Early studies suggest that Melanotan 1 could have effects on cardiovascular health, including lowering blood pressure by activating certain melanocortin receptors which influence cardiovascular regulation.
- Potential Cognitive Benefits: There is preliminary research into whether Melanotan 1’s activation of melanocortin pathways might also influence cognitive functions, possibly offering neuroprotective benefits or improving aspects of cognitive health.
Overview
Melanotan 1 is a synthetic analogue of alphamelanotocyte stimulating hormone. It is used clinically, in Europe, to prevent sun-related skin damage (i.e. phototoxicity) from occurring in people suffering from erythropoietic protoporphyria. Though initially developed as a sunless tanning agent, melanotan 1 has been found to have a number of physiologic effects on blood pressure, feeding behavior, central nervous system function, and more. The peptide is in phase 3 clinical trials for the treatment of polymorphose light eruption and is in phase 2 clinical trials for the treatment of actinic keratosis (a specific type of skin damage caused by the sun) and its more serious counterpart, squamous cell carcinoma.
Structure
The chemical structure of Melanotan 1 (MT-1) is as follows:
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
In this structure:
- “Ac” represents an acetyl group at the N-terminus.
- “Nle” stands for norleucine, a modified amino acid.
- “cyclo” indicates that the peptide contains a cyclic structure.
- The amino acid sequence following “cyclo” represents the sequence of amino acids in Melanotan 1, which is as follows: Asp-His-D-Phe-Arg-Trp-Lys.
This sequence of amino acids is the key component responsible for the biological activity of Melanotan 1, which primarily involves stimulating melanocytes in the skin to produce melanin, resulting in increased skin pigmentation or tanning when used for cosmetic purposes.
How Does Melanotan 1 Work?
Melanotan 1 is very similar to naturally occurring alpha-melanocyte stimulating hormone (alphaMSH). Alpha-MSH is primarily known for its influence on melanocytes, the cells in skin and hair responsible for pigmentation. This function is mediated via strong binding to melanocortin receptor 1. Alpha-MSH is a non-selective full agonist of melanocortin receptors 1, 3, 4, and 5.
Melanotan 1 differs from alpha-MSH by a single amino acid and was actually first developed as a sunless tanning agent. Research into melanocortin receptors and their effects was relatively limited at the time and scientists quickly discovered that while Melanotan 1 did indeed cause pigmentation, it also increased sexual arousal, boosted appetite, and altered baseline metabolism. Subsequent study of Melanotan 1 and other melanocortin-binding proteins helped scientists to better understand the melanocortin signaling system.
Melanotan 1 Research
Melanotan 1 Originally Designed for Sunless Tanning
MT-1 has been studied in phase 1 clinical trials for its effect on tanning in humans exposed to ultraviolet radiation. The research showed that subjects administered MT-1 were 75% more likely to tan and 47% less likely to experience sunburn. Compared to controls, subjects given Melanotan 1 required 50% less exposure to ultraviolet light to achieve equivalent tanning. They also retained their tan for three weeks longer than those exposed only to UV light. There is some thought among scientists that Melanotan 1 could be used to boost tanning in high UV settings to protect against sunburn and the long-term effects of ultraviolet skin damage. This could be particularly useful in individuals with poor-tanning skin types (referred to as type I and type II by the Fitzpatrick scale).
Research in individuals with variant MCl receptors shows that they are less likely to tan than the average individual. As it turns out, administration of Melanotan 1 in this setting increases melanin density and tanning substantially, helping to protect people who do not tan well and are most in need of photoprotection. These are individuals who get limited benefits from sunscreen and, in order to prevent skin cancer, must limit their sun exposure a great deal. This research could open pathways to better UV protection and reduce rates of skin cancer substantially.
There is also interest in using Melanotan 1 to treat vitiligo. A small phase 1 trial showed that using Melanotan 1 in conjunction with UVB light therapy stimulated both melanin production and the proliferation of the melanocytes that produce melanin. Nearly half of treated patients showed improved pigmentation of vitiligo lesions and a faster rate of repigmentation. Research shows that combining Melanotan 1 treatment with existing treatment modalities of vitiligo produces synergistic effects and improved aesthetic outcomes in shorter periods of time. If successful in vitiligo treatment, there may be applications for Melanotan 1 treatment in the setting of hypopigmented scars, etc.
Actinic keratosis, also called solar keratosis, is a crusty scaly growth of skin caused by overexposure to UV light. It is considered a precancerous lesion that will eventually lead to squamous cell carcinoma (one type of skin cancer) if left untreated. There are more than 400,000 cases every year. Though obvious lesions can be removed by a dermatologist or surgeon, the vast majority are so small that they cannot be seen or even felt. Melanotan 1 is being investigated as a possible first-line agent for treating these invisible lesions and for preventing their progression to full-blown skin cancer.
Melanotan-1 Research and Blood Pressure
Research in hypertensive (high blood pressure) mice has revealed that Melanotan 1 can protect against high blood pressure without affecting animals that have normal blood pressure. This is important because current blood pressure medications can cause hypotension, which can lead to loss of consciousness, stroke, heart attack, and more. This side effect of blood pressure medications is more common in the elderly, thanks in part to their labile physiology. The ability to regulate high blood pressure without causing significant lows makes Melanotan 1 the perfect candidate for exploring further drug development.
Cognitive Decline, Alzheimer’s Disease, and Melanotan 1
Research in transgenic mice indicates that Melanotan 1 may protect the brain against the kind of damage that leads to cognitive decline and Alzheimer’s disease. The study, which used a mouse model of moderate Alzheimer’s disease
(AD), indicated that Melanotan 1, even in minuscule doses, reduces the level of amyloid beta plaques in the brain, protects neurons from death, and improves clinical measures of cognitive function as well as laboratory measures of synaptic transmission. In the same study, blocking the effects of Melanotan 1 at the MC4 receptor prevented all of the peptide’s favorable effects.
The benefit of Melanotan 1 action at the MC4 receptor has been explored in other studies as well. Research, also in mice, shows that MC4 receptor stimulation can boost neurogenesis and lead to cognitive recovery in AD. It is one of the few studies to show improvement in the condition rather than simply slowing decline. Once daily administration of MT-1 reduces levels of all AD-related biomarkers, indicating that the peptide actually works through multiple pathophysiological pathways.
The MC4 receptor is the only melanocortin receptor known to be expressed on astrocytes, the cells that protect neurons and provide them with nutrition. Research in rats indicates that Melanotan 1 improves astrocyte functioning by increasing levels of brain-derived neurotrophic factor (BDNF). BDNF is critical to protecting synapse stability and neurogenesis in general.
Melanotan 1 and Functional Recovery Following Stroke
It isn’t just biomarkers in AD that improve following MT-1 treatment. Research in gerbil models of a stroke lasting ten full minutes reveals that treatment with nanomolar doses of Melanotan 2 can reduce brain damage, including neuron death, and improve recovery of learning and memory. What is really exciting is that these effects are achieved even Melanotan 1 is administered 9 hours after a stroke. It is thought that MT-1 activates repair mechanisms that improve synaptic plasticity and promote long-lasting functional recovery by allowing the brain to reroute learning and memory to healthier areas. The lynchpin in this process appears to be the expression of the Zif268 gene. Zif268 is over-expressed in animals given melanotan-1. The same gene is also over-expressed in the models of Alzheimer’s disease showing cognitive improvement.
Melanotan 1 Influences Heart and Circulation
Research in rats undergoing heart attack has shown that Melanotan 1 and other melanocortins can help reduce injury and improve circulatory parameters. Administration of MT-1 during CPR and in conjunction with epinephrine helps to restore baseline arterial pressure and heart rate, reverses metabolic acidosis, reduces inflammatory markers, and improves the expression of genes associated with cardiac function. Overall, the therapy improved the survival rate by 81 %, a substantial increase that may make Melanotan 1 or a similar melanocortin a mainstay of emergency advanced cardiac life support.
Melanotan 1 Research and Neuroinflammatory Disease
Research on Melanotan 1 has revealed that the MCl receptor is responsible for pigmentation in skin and hair. For a long time, it was thought that this was the receptor’s only function. Recent research in mice, however, has indicated that this receptor plays a role in mediating inflammation in the central nervous system. In multiple sclerosis, for instance, helper T cells cause loss of myelin on neurons, which in turn causes neuron dysfunction and even death. In mice, administration of Melanotan 1 interferes with this process and prevents loss of myelin, thus preventing neuron damage. In fact, administration of MT-1 to these mice improved myelin recovery and helped to reestablish neuron
signaling.
Similar effects as above are also seen in mouse models of uveitis, an inflammatory disorder of the eye that can cause pain and vision loss. Current treatments have a range of side effects, so scientists are constantly searching for alternatives to steroids and immunosuppressive drugs. Alpha-MSH acts to suppress T-cell function, a property mediated through the MC4 receptor and thus mimicked by MT-1. Surprisingly, local administration of MC4 receptor agonists directly to the eye is as effective as systemic administration. This route of administration helps to eliminate systemic side effects.
Melanotan 1 Investigated in Fat Loss Trials
Melanotan 1 works on several melanocortin receptors, including the MC5 receptor. Stimulation of MC5R promotes the oxidation of fatty acids by muscle and shifts fat cells from fat storage to fat burning. These findings in mice also reveal that the fat burning caused by melanocortin stimulation is complex and involves several receptors and physiologic pathways. That said, Melanotan 1 is useful to scientists wishing to explore how fatty acid metabolism can be altered and offers the tantalizing ability to boost baseline physiology without the need for exercise, which could be of tremendous benefit in individuals who are unable to exercise due to morbid obesity, disability, or injury.
Dosing Protocol for Research Purposes
- Enhancing Consciousness: A minimum effective dose (MED) of 0.25 mg injected subcutaneously 1-2 times in the morning per week.
- Skin Tanning: 0.5 mg injected subcutaneously twice per day, increasing the daily dosage to 1.5 per mg by the 3rd/4th day and then stopping after one week.
About The Author
Research by L. Edmiston, M.D. L. Edmiston holds an M.D. from Case Western Reserve University School of Medicine and a B.S. in molecular biology.
References
- “Effects of a Superpotent Melanotropic Peptide in Combination With Solar UV Radiation on Tanning of the Skin in Human Volunteers I Dermatology! JAMA Dermatology I JAMA Network.”
- “Effect of MELANOTAN, [Nle(4), D-Phe(7)]: alpha-MSH, on melanin synthesis in humans with MClR variant alleles. – PubMed – NCBI.” [Online]. Available:
https://www.ncbi.nlm.nih.gov/pubmed/162933 41. [Accessed: 24-Jun-20191:, - “Afamelanotide and narrowband UV-B phototherapy for the treatment of vitiligo: a randomized multicenter trial.” [Online].:. Available:
https://reference. med scape .com/med I ine/abstract/25230094. [Accessed: 24-Jun-20191. - “Advances in Vitiligo: An Update on Medical and Surgical Treatments.” [Online]. Available: https://reference. med scape .com/medline/abstract/28210378. [Accessed: 24-Jun-20191:
- “a-MSH analogue attenuates blood pressure elevation in DOCA-salt hypertensive mice. – PubMed – NCBI.” [Online]. Available:
https://www.ncbi.nlm.nih.gov/pubmed/239773 63. [Accessed: 24-Jun-2019]. - “Melanocortins protect against brain damage and counteract cognitive decline in a transgenic mouse model of moderate Alzheimer’s disease. – PubMed – NCBI.”
[Online]. Available: https://www.ncbi.nlm.nih.gov/pubmed/250348 07. [Accessed: 24 https://www.ncbi.nlm.nih.gov/pubmed/26003413 - “NDP-a-MSH induces intense neurogenesis and cognitive recovery in Alzheimer transgenic mice through activation of melanocortin MC4 receptors. – PubMed – NCBI.” [Online]. Available:
- “Melanocortins protect against progression of Alzheimer’s disease in triple-transgenic mice by targeting multiple pathophysiological pathways. – PubMed – NCBI.” [Onlinel_ Available: https://www.ncbi.nlm.nih.gov/pubmed/240945 79. [Accessed: 24-Jun-20191].
- “Melanocortin 4 receptor activates ERK-cFos pathway to increase brain-derived neurotrophic factor expression in rat astrocytes and hypothalamus. – PubMed -NCBI.” [Online]. Available: https://www.ncbi.nlm.nih.gov/pubmed/258924 44. [Accessed: 24-Jun-20191].
- “Functional recovery after delayed treatment of ischemic stroke with melanocortins is associated with overexpression of the activity..: dependent gene … – PubMed – NCBI.”
[Online]. Available: https://www.ncbi.nlm.nih.gov/pubmed/193457 27. [Accessed: 24-Jun-20191]. - “Protective effects of the melanocortin analog NDP-a-MSH in rats undergoing cardiac arrest. – PubMed – NCBI.” [Online]. Available: https://www.ncbi.nlm.nih.gov/pubmed/254469 29. [Accessed: 24-Jun-20191}.
- “Melanocortin-1 receptor activation is neuroprotective in mouse models of neuroinflammatory disease. – PubMed – NCBI.” [Online]. Available: https://www.ncbi.nlm.nih.gov/Rubmed/277979 62. [Accessed: 24-Jun-20191].
- “immunosuppressive activity of a novel peptide analog of a-melanocyte stimulating hormone (a-MSH) in experimental autoimmune uveitis. – PubMed – NCBI.”
[Online]. Available: https://www.ncbi.nlm.nih.gov/pubmed/216403 92. [Accessed: 24-Jun-20191]. - “Peripheral effect of alpha-melanocyte stimulating hormone on fatty acid oxidation in skeletal muscle. – PubMed – NCBI.” [Online]:. Available:
https://www.ncbi.nlm.nih.gov/pubmed/171276 74. [Accessed: 24-Jun-2019]. - “Characterization of murine melanocortin receptors mediating adipocyte lipolysis and examination of signaling pathways involved. – PubMed – NCBI.” [Online]. Available:
https://www.ncbi.nlm.nih.gov/pubmed/216161 21. [Accessed: 24-Jun-20191].