Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review

Barbie drug identification: Not a child's play

Various samples-including two vials with a pharmaceutical appearance-were submitted to the laboratory for identification. The aim of this work was to describe the unique characteristics observed during the analysis of the powder contained in the vial. Samples were submitted to HPLC-DAD, UHPLC-TOF-MS, and/or UPLC-MS-MS analysis. The majority of the samples were easily identified as standard drugs of abuse. The main difficulty lay in identifying the powder in the vials. No match was found in the library through HPLC-DAD analysis. Fortunately, the vials were labeled as "Melanotan II", although the UV spectrum was not available. Mass spectrometric analysis of melanotan II was challenging, as it is a small peptide with a molecular weight of 1024 Da, which is significantly heavier than classical drugs that the laboratory usually handles. As a result, mass spectrometer's parameters can be limited to detect masses up to 1000 Da. Additionally, melanotan II is multi-charged which is also unusual for compounds typically targeted in our daily work. Finally, the reference standard allowed us to confirm the identification with both instruments, and determine the purity of 30%. Melanotan II is not approved on the market due to safety concerns. It is used illegally mainly for tanning, explaining its nickname "Barbie drug". To conclude, analysis of melanotan II was challenging as it is heavy and doubly charged. Moreover, its UV spectrum was initially not available in the literature. The difficulties faced by forensic scientists in detecting this drug may explain its popularity on the illicit market.

Evolution of biosynthetic human insulin and its analogues for diabetes management

Hormones play a crucial role in maintaining the normal human physiology. By acting as chemical messengers that facilitate the communication between different organs, tissues and cells of the body hormones assist in responding appropriately to external and internal stimuli that trigger growth, development and metabolic activities of the body. Any abnormalities in the hormonal composition and balance can lead to devastating health consequences. Hormones have been important therapeutic agents since the early 20th century, when it was realized that their exogenous supply could serve as a functional substitution for those hormones which are not produced enough or are completely lacking, endogenously. Insulin, the pivotal anabolic hormone in the body, was used for the treatment of diabetes mellitus, a metabolic disorder due to the absence or intolerance towards insulin, since 1921 and is the trailblazer in hormone therapeutics. At present the largest market share for therapeutic hormones is held by insulin. Many other hormones were introduced into clinical practice following the success with insulin. However, for the six decades following the introduction the first therapeutic hormone, there was no reliable method for producing human hormones. The most common source for hormones were animals, although semisynthetic and synthetic hormones were also developed. However, none of these were optimal because of their allergenicity, immunogenicity, lack of consistency in purity and most importantly, scalability. The advent of recombinant DNA technology was a game changer for hormone therapeutics. This revolutionary molecular biology tool made it possible to synthesize human hormones in microbial cell factories. The approach allowed for the synthesis of highly pure hormones which were structurally and biochemically identical to the human hormones. Further, the fermentation techniques utilized to produce recombinant hormones were highly scalable. Moreover, by employing tools such as site directed mutagenesis along with recombinant DNA technology, it became possible to amend the molecular structure of the hormones to achieve better efficacy and mimic the exact physiology of the endogenous hormone. The first recombinant hormone to be deployed in clinical practice was insulin. It was called biosynthetic human insulin to reflect the biological route of production. Subsequently, the biochemistry of recombinant insulin was modified using the possibilities of recombinant DNA technology and genetic engineering to produce analogues that better mimic physiological insulin. These analogues were tailored to exhibit pharmacokinetic and pharmacodynamic properties of the prandial and basal human insulins to achieve better glycemic control. The present chapter explores the principles of genetic engineering applied to therapeutic hormones by reviewing the evolution of therapeutic insulin and its analogues. It also focuses on how recombinant analogues account for the better management of diabetes mellitus.

Melanocortin agonism in a social context selectively activates nucleus accumbens in an oxytocin-dependent manner

Social deficits are debilitating features of many psychiatric disorders, including autism. While time-intensive behavioral therapy is moderately effective, there are no pharmacological interventions for social deficits in autism. Many studies have attempted to treat social deficits using the neuropeptide oxytocin for its powerful neuromodulatory abilities and influence on social behaviors and cognition. However, clinical trials utilizing supplementation paradigms in which exogenous oxytocin is chronically administered independent of context have failed. An alternative treatment paradigm suggests pharmacologically activating the endogenous oxytocin system during behavioral therapy to enhance the efficacy of therapy by facilitating social learning. To this end, melanocortin receptor agonists like Melanotan II (MTII), which induces central oxytocin release and accelerates formation of partner preference, a form of social learning, in prairie voles, are promising pharmacological tools. To model pharmacological activation of the endogenous oxytocin system during behavioral therapy, we administered MTII prior to social interactions between male and female voles. We assessed its effect on oxytocin-dependent activity in brain regions subserving social learning using Fos expression as a proxy for neuronal activation. In non-social contexts, MTII only activated hypothalamic paraventricular nucleus, a primary site of oxytocin synthesis. However, during social interactions, MTII selectively increased oxytocin-dependent activation of nucleus accumbens, a site critical for social learning. These results suggest a mechanism for the MTII-induced acceleration of partner preference formation observed in previous studies. Moreover, they are consistent with the hypothesis that pharmacologically activating the endogenous oxytocin system with a melanocortin agonist during behavioral therapy has potential to facilitate social learning.

Alpha-melanocyte stimulating hormone (α-MSH): biology, clinical relevance and implication in melanoma

Alpha-melanocyte stimulating hormone (α-MSH) and its receptor, melanocortin 1 receptor (MC1R), have been proposed as potential target for anti-cancer strategies in melanoma research, due to their tissue specific expression and involvement in melanocyte homeostasis. However, their role in prevention and treatment of melanoma is still debated and controversial. Although a large body of evidence supports α-MSH in preventing melanoma development, some preclinical findings suggest that the α-MSH downstream signalling may promote immune escape and cancer resistance to therapy. Additionally, in metastatic melanoma both MC1R and α-MSH have been reported to be overexpressed at levels much higher than normal cells. Furthermore, targeted therapy (e.g. BRAF inhibition in BRAFV600E mutant tumours) has been shown to enhance this phenomenon. Collectively, these data suggest that targeting MC1R could serve as an approach in the treatment of metastatic melanoma. In this review, we explore the molecular biology of α-MSH with particular emphasis into its tumor-related properties, whilst elaborating the experimental evidence currently available regarding the interplay between α-MSH/MC1R axis, melanoma and antitumor strategies.

LC-HRMS characterization of the skin pigmentation and sexual enhancers melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs

The spread of performance and image enhancing drugs (PIEDs) often requires forensic toxicology laboratories to identify unknown compounds without reference standards. We characterized the PIEDs melanotan II and bremelanotide, not legally marketed, in eight unknown samples confiscated by police together with anabolic steroids, hormone modulators, sexual enhancers and stimulants, intended for the black market of bodybuilders, using liquid chromatography-high resolution/high accuracy Orbitrap mass spectrometry (LC-HRMS). The characterization was carried out by the accurate mass measurements of MH⁺ ionic species, the study of their isotopic patterns and the associated relative isotopic abundance (RIA) values, as well as the accurate mass measurements of collision-induced product ions obtained in fragmentation experiments. LC-HRMS confirmed itself as a powerful analytical tool to elucidate the elemental composition and structural characteristics of unknown compounds.

Advances in the Design of Genuine Human Tyrosinase Inhibitors for Targeting Melanogenesis and Related Pigmentations

Human tyrosinase (hsTYR) is the key enzyme ensuring the conversion of l-tyrosine to dopaquinone, thereby initiating melanin synthesis, i.e., melanogenesis. Although the protein has long been familiar, knowledge about its three-dimensional structure and efficient overexpression protocols emerged only recently. Consequently, for decades medicinal chemistry studies aiming at developing skin depigmenting agents relied almost exclusively on biological assays performed using mushroom tyrosinase (abTYR), producing a plethoric literature, often of little useful purpose. Indeed, several recent reports have pointed out spectacular differences in terms of interaction patterns and inhibition values between hsTYR and abTYR, including for widely used standard tyrosinase inhibitors. In this review, we summarize the last developments regarding the potential role of hsTYR in human pathologies, the advances in recombinant expression systems and structural data retrieving, and the pioneer generation of true hsTYR inhibitors. Finally, we present suggestions for the design of future inhibitors of this highly attractive target in pharmacology and dermocosmetics.

Combining MALDI mass spectrometry imaging and droplet-base surface sampling analysis for tissue distribution, metabolite profiling, and relative quantification of cyclic peptide melanotan II

Peptides have become a fast-growing segment of the pharmaceutical industry over the past few decades. It is essential to develop cutting edge analytical techniques to support the discovery and development of peptide therapeutics, especially to examine their absorption, distribution, metabolism and excretion (ADME) properties. Herein, we utilized two label-free mass spectrometry (MS) based techniques to investigate representative challenges in developing therapeutic peptides, such as tissue distribution, metabolic stability and clearance. A tool proof-of-concept cyclic peptide, melanotan II, was used in this study. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), which is a well-developed label-free imaging technique, was used to map the detailed molecular distribution of melanotan II and its metabolites. Droplet-based liquid microjunction surface sampling liquid chromatography-high resolution mass spectrometry (LMJ-SSP-LC-HRMS) was used in combination with MALDI-MSI to rapidly profile molecular information and provide structural insights on drug and metabolites. Using both techniques in parallel allowed a more comprehensive and complementary data set than using either technique independently. We envision MALDI-MSI and droplet-based LMJ-SSP-LC-HRMS, which can be used in combination or as standalone techniques, to become valuable tools for assessing the in vivo fate of peptide therapeutics in support of drug discovery and development.

An overview on performance and image enhancing drugs (PIEDs) confiscated in Italy in the period 2017-2019

CONTEXT

The illegal market of counterfeit and falsified medicines and supplements containing unlabeled pharmaceuticals is expanding worldwide. They are usually referred to by the term "performance and image enhancing drugs" (PIEDs) and are mainly steroids, stimulants, hormones, and drugs for erectile dysfunction. PIEDs are easily accessible through the online or black markets. We analyzed over 400 such medicines confiscated in Italy in the period 2017-2019, to determine their composition.

METHODS

Confiscated products were analyzed by gas chromatography/mass spectrometry and liquid chromatography/high-resolution mass spectrometry, in order to ascertain their composition and to evaluate the correspondence between what was declared on the label and the actual content, or to identify unknown products.

RESULTS

The most commonly found substance was anabolic steroids, found in 64% of products, with 11% containing hormone modulators, 6% stimulants, 6% sexual enhancers (mainly sildenafil) and other drugs, including thyroid hormones, melanin stimulators, and vitamins. These substances were often in mixtures. The products were often mislabeled, containing contaminants in addition to the drug declared, or consisted of a drug completely different from the one reported on the label. Fifteen percent of products had a qualitative composition completely different from that declared, while 10% of products showed cross-contamination with other drugs, mainly testosterone esters, probably due to the presence of residues of other drugs in the production line. In addition, 11% of products were not labeled, so their purported composition was unknown.

DISCUSSION

PIEDs pose a threat to public health. The main risks are related to the intrinsic toxicity of the substances found, especially when taken without a therapeutic indication. Another issue is related to the mislabeling of the fake medicines, and the poor-quality standard of counterfeit product preparation, with additional risks of the presence of other toxic ingredients or microbial contamination.

CONCLUSIONS

The use of counterfeit products is a public health concern, as it constitutes a high risk for consumer health. It is mainly caused by the uncontrolled use of steroids, stimulants, sexual enhancers, and other medicaments, without medical indication or supervision, with variable and unknown compositions and doses, as well as other contaminants as a result of the absence of good manufacturing practices.

Topical MTII Therapy Suppresses Melanoma Through PTEN Upregulation and Cyclooxygenase II Inhibition

Melanotan II (MTII), a synthetic analogue of the alpha-melanocyte stimulating hormone (α-MSH), has been applied for skin tanning in humans. However, the carcinogenic consequence of topical MTII has been equivocal. This study aims to delineate the anti-neoplastic efficacy and mechanism of MTII using the B16-F10 melanoma model in vitro and in vivo. It was found that, despite a lack of influence on proliferation, MTII potently inhibited the migration, invasion, and colony-forming capability of melanoma cells. Moreover, topical MTII application significantly attenuated the tumor progression in mice bearing established melanoma. Histological analysis revealed that MTII therapy induced apoptosis while inhibiting the proliferation and neovaluarization in melanoma tissues. By immunoblot and immunohistochemical analysis, it was found that MTII dose-dependently increased the phosphatase and tensin homolog (PTEN) protein level while reducing PTEN phosphorylation, which resulted in the inhibition of AKT/nuclear factor kappa B (NFκB) signaling. Consistently, MTII treatment inhibited cyclooxygenase II (COX-2) expression and prostaglandin E2 (PGE2) production in melanoma cells. Finally, studies of antibody neutralization suggest that the melanocortin 1 receptor (MC1R) plays a critical role in MTII-induced PTEN upregulation and melanoma suppression. Together, these results indicate that MTII elicits PTEN upregulation via MC1R, thereby suppressing melanoma progression through downregulating COX-2/PGE2 signaling. Hence, topical MTII therapy may facilitate a novel therapeutic strategy against melanoma.

It takes one to know one: exploring patient dialogue on rosacea web-based platforms and their potential for significant harm

BACKGROUND

Rosacea is a non-curable skin condition, leading patients to turn self-management options from web-based platforms. Self-management can be dangerous possibly under-reported.

AIM

To discover the extent of online material and determine the potential for harm influenced by rosacea internet sources.

MATERIAL AND METHODS

Material analyzed included search engines, apps, YouTube, forums and Facebook groups. As Facebook and forums were most active, they became the core focus. A passive 'fly on the wall' approach allowed observation of user posts and their content.

RESULTS

Three broad categories of dialogue were identified: prescribed medications, non-prescribed remedies and, most commonly, posts aimed to elicit emotional support. From this, positive and negative influences were identified. Negative influences were divided into four domains: physical harm, financial harm, emotional harm, and detrimental influences on patient-doctor relationships.

CONCLUSIONS

Rosacea patients may be susceptible to rely on peer-generated information. Forums can have detrimental outcomes, primarily due to lack of monitoring and the potential for misplaced trust between fellow sufferers, encouraging others to try potentially harmful alternative remedies. Lack of monitoring allows the spread of inaccurate information, which can result in harm. Medical practitioners should be aware of trending online dialogue and self-treatment remedies to facilitate patient safety.