Melatonin and Circadian Rhythm: Aging, Cancer, and Mechanism

Kovacic, Peter; Somanathan, Ratnasamy

doi:10.4236/ojpm.2014.47065

Cited by 7 publications

(3 citation statements)

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“…However, the effect of MEL in a complex active topical mixture was not sufficiently investigated [ 40 ]. MEL, C 13 H 16 N 2 O 2 , N -acetyl-5-methoxy-tryptamine, is an indole amine, a natural hormone that is produced in a circadian manner by the pineal gland and in smaller quantities by the brain, bone marrow, retina, ciliary body, thymus, placenta, gonads, gastrointestinal tract, and skin [ 41 , 42 , 43 ]. Most of the MEL involved in physiological and pathological processes is generated by the pineal cells, where the sequential action of arylalkylamine N -acetyltransferase and hydroxy indole- O -methyltransferase on serotonin takes place on tryptophan, its precursor [ 44 , 45 ].…”

Section: Introductionmentioning

confidence: 99%

“…Starting from the studies of Pagnacco et al [ 64 ] who assessed the antibacterial, anti-edematous, and anti-inflammatory effects of HA when used as a topical treatment for periodontitis in a clinical trial, we decided to use HA as a matrix for antibiotics and MEL. Additionally, in the gingival crevicular fluid, a naturally high level of HA was determined, while it was absent in cases of gingivitis or periodontitis [ 41 ]. Thus, it is possible to evaluate the presence and degree of periodontitis considering HA as a marker.…”

Section: Introductionmentioning

confidence: 99%

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Considerations on the Controlled Delivery of Bioactive Compounds through Hyaluronic Acid Membrane

et al. 2022

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(1) Background: The standard treatment for periodontal disease, a chronic inflammatory state caused by the interaction between biofilms generated by organized oral bacteria and the local host defense response, consists of calculus and biofilm removal through mechanical debridement, associated with antimicrobial therapy that could be delivered either systemically or locally. The present study aimed to determine the effectiveness of a hyaluronic acid membrane matrix as a carrier for the controlled release of the active compounds of a formulation proposed as a topical treatment for periodontal disease, and the influence of pH on the complex system’s stability. (2) Methods: The obtained hyaluronic acid (HA) hydrogel membrane with dispersed melatonin (MEL), metronidazole (MZ), and tetracycline (T) was completely characterized through FTIR, XRD, thermal analysis, UV-Vis and fluorescence spectroscopy, fluorescence microscopy, zeta potential and dielectric analysis. The MTT viability test was applied to check the cytotoxicity of the obtained membranes, while the microbiological assessment was performed against strains of Staphylococcus spp. and Streptococcus spp. The spectrophotometric investigations allowed to follow up the release profile from the HA matrix for MEL, MZ, and T present in the topical treatment considered. We studied the behavior of the active compounds against the pH of the generated environment, and the release profile of the bioactive formulation based on the specific comportment towards pH variation. The controlled delivery of the bioactive compounds using HA as a supportive matrix was modeled applying Korsmeyer–Peppas, Higuchi, first-order kinetic models, and a newly proposed pseudo-first-order kinetic model. (3) Results: It was observed that MZ and T were released at higher active concentrations than MEL when the pH was increased from 6.75, specific for patients with periodontitis, to a pH of 7.10, characterizing the healthy patients. Additionally, it was shown that for MZ, there is a burst delivery up to 2.40 × 10−5 mol/L followed by a release decrease, while for MEL and T a short release plateau was recorded up to a concentration of 1.80 × 10−5 mol/L for MEL and 0.90 × 10−5 mol/L for T, followed by a continuous release; (4) Conclusions: The results are encouraging for the usage of the HA membrane matrix as releasing vehicle for the active components of the proposed topical treatment at a physiological pH.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Considerations on the Controlled Delivery of Bioactive Compounds through Hyaluronic Acid Membrane

et al. 2022

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“…Although tryptophan ( TRP ) also shows antioxidant and free-radical scavenging activity, , MLT is much more effective due to its cascade effect, , distinguishing it from other classical antioxidants, where together with its secondary and tertiary metabolites, it can be 1 order of magnitude more effective. In humans the role of MLT has been studied in antiaging, − immune system regulation, oncostasis among its many others. A review of its wide range of clinical uses in humans is available …”

Section: Introductionmentioning

confidence: 99%

Low-Energy Electron Interaction with Melatonin and Related Compounds

et al. 2017

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The electron attaching properties and fragmentation of temporary negative ions of melatonin and its biosynthetic precursor tryptophan are studied in vacuo using dissociative electron attachment (DEA) spectroscopy. The experimental findings are interpreted in silico with the support of Hartree-Fock and density functional theory calculations of empty orbital energies and symmetries, and evaluation of the electron affinities of the indolic molecules under investigation. The only fragment anions formed by DEA to melatonin at incident electron energies below 2 eV are associated with the elimination of a hydrogen atom (energetically favored from the NH site of the pyrrole ring, leaving the ring intact) or a CH radical from the temporary molecular negative ion. Opening of the pyrrole ring of melatonin is not detected over the whole electron energy range of 0-14 eV. The DEA spectra of l- and d-tryptophan are almost identical under the present experimental conditions. The adiabatic electron affinity of melatonin is predicted to be -0.49 eV at the B3LYP/6-31+G(d) level, indicating that the DEA mechanism in melatonin is likely to be present in most life forms given the availability of low energy electrons in living systems in both plant and animal kingdoms. In particular, H atom donation usually associated with free-radical scavenging activity can be stimulated by electron attachment and N-H bond cleavage at electron energies around 1 eV.

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