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Novel delivery system in REMfresh mimics the way the body naturally releases and maintains melatonin over a 7-hour period

Real-world evidence confirms previous clinical data on improved sleep duration and sleep quality with REMfresh

Reporter: Gail S. Thornton, M.A.

Chronic disorders of sleep and wakefulness affect an estimated 50-70 million adults in the United States.[i] The cumulative long term effects of sleep loss have been associated with a wide range of damaging health consequences, including obesity, diabetes, impaired glucose tolerance, cardiovascular disease, hypertension, anxiety and depression.[ii]In terms of preventing health consequences, sleeping 6-8 hours per night consistently may provide optimal health outcomes.[iii]

This month, real-world evidence from two recently completed patient-reported outcomes (PRO) studies presented at SLEEP 2019 in San Antonio, Texas, confirms previous clinical data demonstrating statistically significant improvements in sleep onset, sleep duration, sleep maintenance and sleep quality with REMfresh®, the first and only continuous release and absorption melatonin (CRA-Melatonin™). This data supports and reinforces the benefits of REMfresh, which is designed to give patients up to 7 hours of sleep support. PRO studies of this kind, which more closely address real-world patient experience, are increasingly being recognized by regulatory authorities and academia in evaluating new therapies.

The REMfresh Duration Validation (REMVAL) study provides further evidence of a correlative relationship between the 7-hour pharmacokinetic profile observed in the earlier clinical study, REM Absorption Kinetics Trial (REMAKT), and the hypnotic effects of REMfresh, observed in subsequent studies, as demonstrated by improvements in sleep onset, sleep duration, sleep maintenance, sleep quality and patient satisfaction. This latest study further validates the findings of past studies that have been presented and undergone peer review at major sleep conferences:  

  • REMfresh Patient Reported Outcomes DURation (REMDUR), the first, 500-patient, PRO study of this sleep brand, presented at the annual meeting for sleep specialists, SLEEP 2018, which demonstrated that more than 77 percent of patients achieved 6 or more hours of sleep compared to 23.6 percent who slept that duration prior to taking REMfresh (p<.0001)[iv], and
  • REM Absorption Kinetics Trial (REMAKT), a pharmacokinetic study presented at SLEEP 2017 and 2018, which demonstrated that REMfresh mimics the body’s own seven-hour Mesa-Wave® release profile, a natural pattern of melatonin blood levels during a normal night’s sleep cycle.[v] 

An additional PRO subset study, part of REMVAL, called the REMfresh Short Sleep Cohort Assessment (REMSS), assessed improvements in sleep duration and sleep maintenance among 311 patients with morbid or extreme short sleep duration of 4 hours or less.

These two PRO studies (REMVAL and REMSS) were presented at SLEEP 2019, the 33rd Annual Meeting of the Associated Professional Sleep Societies (APSS), which is a joint meeting of the American Academy of Sleep Medicine and the Sleep Research Society, held in San Antonio, Texas, from June 8-12.

“These latest findings provide further confirmation of the potential for nonprescription REMfresh to help address the public health issue of  the cumulative effects of sleep loss,” said David C. Brodner, M.D., a leading sleep specialist who is Double Board-Certified in Otolaryngology — Head and Neck Surgery as well as Sleep Medicine, Founder and Principle Physician at the Center for Sinus, Allergy, and Sleep Wellness, in Palm Beach County, Florida, and Senior Medical Advisor for Physician’s Seal, LLC. “Based on a novel Ion Powered Pump® (IPP®) delivery system that provides a pharmacokinetic (PK) profile that more closely aligns with the body’s own natural sleep pattern, REMfresh has demonstrated once again promising results and high levels of satisfaction in a real-world population of patients who have had chronic difficulties sleeping, providing up to seven hours of sleep support,” said Dr. Brodner.

Topline findings of these studies are as follows:

  • The 1,116 patient-reported outcomes (PRO) study, REMfresh Duration Validation (REMVAL), found that after taking 99 percent ultra-pure, continuous release and absorption melatonin (REMfresh®, CRA-melatonin™), the majority (78.8 percent) of patients involved achieved a sleep duration of greater than or equal to 6 hours (p<.0001), while more than 91 percent of patients reported a major/moderate improvement in sleep onset, sleep maintenance and sleep quality (p<.0001).  Of the 30.7 percent of patients (342 in total), who reported never having taken other brands of melatonin, 99.4 percent indicated they were likely or very likely to continue taking CRA-melatonin for their sleep issues (p<.0001).
  • REMVAL provides further real-world evidence of a correlative relationship between the originally observed 7-hour pharmacokinetic profile in the REM Absorption Kinetics Trial (REMAKT) and the strong observed hypnotic effects of CRA-melatonin, as demonstrated by improvements in sleep onset, sleep duration, sleep maintenance and sleep quality.
  • A second PRO subset study, REMfresh Short Sleep Cohort Assessment (REMSS), involving 311 patients who reported sleeping four hours or less nightly from the REMVAL study, found that 95.8 percent of patients who previously experienced daily, morbid short sleep duration of less than or equal to 4 hours reported an improvement in sleep duration (p<.0001), including more than 46 percent who achieved a sleep duration of greater than or equal to 6 hours (p<.0001). More than 93 percent of patients reported a major/moderate improvement in sleep onset, sleep maintenance and sleep quality (p<.0001).
  • REMVAL and REMSS also provides validation of the results from the previously peer-reviewed and presented clinical study, REMAKT, which demonstrated that REMfresh mimics the body’s own 7-hour Mesa Wave®, a natural pattern of melatonin blood levels during a normal night’s sleep cycle and the 500-patient, peer-reviewed and presented  REMfresh® Patient Reported Outcomes DURation (REMDUR) study, that demonstrated statistically significant improvements in sleep onset, sleep maintenance and sleep quality.

REMVAL Study Describes Improvements in Sleep Duration and Sleep Quality

The poster entitled, “Observed Hypnotic Effects with a Continuous-Release Ion Powered Pump Melatonin Delivery System: Self-Reported Patient Outcomes Study Results Demonstrating Improvement in Sleep Duration and Quality,” reported findings provides further real-world evidence of a correlative relationship between the originally observed 7-hour pharmacokinetic profile in the REM Absorption Kinetics Trial (REMAKT) and the strong hypnotic effects of CRA-melatonin observed in subsequent studies and may offer a new low-dose, drug-free alternative to prescription hypnotics to treat chronic sleep disturbances.

The 1,116-patient REMVAL study was designed to obtain clinically relevant information about patients’ past usage of melatonin and non-melatonin sleep aids, sleep patterns prior to taking CRA-melatonin, sleep duration before and after taking CRA-melatonin, frequency of CRA-melatonin usage, improvement in sleep onset, sleep maintenance and sleep quality after taking CRA-melatonin, and overall satisfaction with CRA-melatonin.

In the study, patients with sleep disturbances in the general population received a sample of REMfresh from their physicians and were invited to complete a 13-question online survey. After taking REMfresh, the majority (78.8 percent) of patients achieved a sleep duration of greater than or equal to 6 hours (p<.0001). More than 91 percent of patients reported a major/moderate improvement in sleep onset, sleep maintenance and sleep quality (p<.0001). Of the 30.7 percent of patients (342 in total), who reported never having taken other brands of melatonin, 99.4 percent indicated they were likely or very likely to continue taking REMfresh for their sleep issues (p<.0001).

REMSS Study Shows Improvement in Patients with Chronic, Extreme Short Sleep

The poster entitled, “Improvement in Sleep Duration and Maintenance with Ion Powered Continuous Release and Absorption Melatonin in a Cohort of Patients with Chronic Short Sleep Duration: Results from a Patient-Reported Outcomes Study,” highlighted findings from the REMfresh Short Sleep Cohort Assessment (REMSS), involving a cohort of 311 patients from the REMVAL study who reported sleeping four hours or less nightly. This cohort analysis was designed to obtain clinically relevant information from these patients experiencing morbid short sleep disturbances, including sleep patterns and melatonin usage before taking REMfresh, sleep duration before and after taking REMfresh, improvement in sleep onset, sleep maintenance and sleep quality after taking REMfresh, and overall product satisfaction.

Data from this cohort show that 95.8 percent of patients who previously experienced daily, morbid short sleep duration of less than or equal to 4 hours reported an improvement in sleep duration (p<.0001), including more than 46 percent who achieved a sleep duration of greater than or equal to 6 hours (p<.0001). This increase from less than or equal to 4 hours to greater than or equal to 6 hours represents a major sleep duration upgrade in this group facing morbid sleep disturbances. More than 93 percent of patients reported a major/moderate improvement in sleep onset, sleep maintenance and sleep quality (p<.0001). Ninety-nine percent of the patients suffering with morbid short sleep (27.2 percent of whom had never previously tried a melatonin brand) reported that they were very likely or likely to continue using CRA-melatonin. These results provide real-world evidence that CRA-melatonin with its extended 7-hour pharmacokinetic  plateau time and benign safety-profile may be a practical baseline therapy to improve sleep duration and other key sleep parameters, including, sleep maintenance and sleep quality in this group of patients who have a higher risk of all-cause mortality.[vi]˒[vii]˒[viii]˒[ix]

Statistics & Data Corporation (SDC), a top-tier clinical data services provider, has independently determined that the number of participants in the study provides adequate power (>90%) to detect even small improvements in sleep outcomes. This high power, or probability of seeing statistically significant results if CRA-melatonin is truly working to improve sleep outcomes, applies to the overall study population (REMVAL) as well as the cohort of short sleepers (REMSS). SDC has subsequently independently validated the statistical results achieved, (e.g., p-values and statistical language).

The Increasing Appreciation of PRO Studies to Include Patient Experience 
Increasingly, there is an appreciation by the U.S. Congress, regulatory authorities and academia, of the substantive value that real-world patient experience brings to assessing new therapies. In addition to the traditional randomized, placebo-controlled trial studies, regulatory authorities are now incorporating the patient perspective in their decision making, including PRO studies. A PRO study is a measurement based on a report that comes directly from the patient about the status or change in their health condition and without amendment or interpretation of the patient’s response by health-care intermediaries. PRO measures can be used to capture a patient’s everyday experience outside of the clinician’s office, and the effects of a treatment on the patient’s activities of daily living.[x]˒[xi]Together, clinical measures and PRO measures can provide a fuller picture of patient benefit.

REMAKT Clinical Study Presented at Past Medical Meetings 
Pharmacokinetic data on REMfresh® was peer-reviewed and then presented in 2017 and 2018 at SLEEP, the Annual Meeting of the Associated Professional Sleep Societies LLC (APSS), and a joint meeting of the American Academy of Sleep Medicine (AASM) and the Sleep Research Society (SRS). 

The study, REM Absorption Kinetics Trial (REMAKT), was a U.S.-based randomized, crossover pharmacokinetic (PK) evaluation study in healthy, non-smoking adults that compared REMfresh (CRA-melatonin) with a market-leading, immediate-release melatonin (IR-melatonin). The study found that melatonin levels with REMfresh exceeded the targeted sleep maintenance threshold for a median of 6.7 hours, compared with 3.7 hours with the leading IR-melatonin. Conversely, the levels of the market-leading IR-melatonin formulation dramatically increased 23 times greater than the targeted levels of exogenous melatonin for sleep maintenance and then had a rapid decline in serum levels that did not allow melatonin levels to be maintained beyond 4 hours. 

Analysis presented at SLEEP 2017 and 2018 showed that REMfresh builds upon the body of evidence from prolonged-release melatonin (PR-M), approved by the European Medicines Agency (EMA) in 2007 as a prescription drug for insomnia, which demonstrated in well-conducted, placebo-controlled studies, statistically significant improvement in sleep quality, morning alertness, sleep onset and quality of life in patients aged 55 years and older compared with placebo.[xv] REMfresh was designed to overcome the challenges of continuous release and absorption in the intestines, thereby extending the continual and gradual release pattern of melatonin through the night (known as the Mesa Wave®, a flat-topped hill with steep sides).[xvi] There was the desirable fast time to reach the sleep threshold level, which is anticipated to result in improved sleep onset, while the extended median plateau time to 6.7 hours and rapid fall-off in plasma levels at the end of the Mesa Wave may help to improve sleep maintenance and morning alertness. 

Over 5,000 healthcare practitioners are estimated to have used REMfresh for their patients and about 320,000 patients are estimated to have purchased and used REMfresh. The continuing, rapid acceptance of REMfresh by patients is observable by several markers, including rapid sales growth and availability among major drug retailers.

###

Data Presented at SLEEP 2019 Poster Sessions:

Monday, June 10, 2019, 5:15-7:15pm

  • (Abstract 0398, Poster Board #135) Improvement in Sleep Duration and Maintenance with Ion Powered Continuous Release and Absorption Melatonin in a Cohort of Patients with Chronic Short Sleep Duration: Results from a Patient-Reported Outcomes Study
    • David J. Seiden, M.D., FAASM,  David Brodner, M.D., Syed M. Shah, Ph.D.
  • (Abstract 0399, Poster Board #136) Observed Hypnotic Effects with a Continuous-Release Ion Powered Pump Melatonin Delivery System: Self-Reported Patient Outcomes Study Results Demonstrating Improvement in Sleep Duration and Quality
    • David J. Brodner, M.D., David J. Seiden, M.D. FAASM, Syed M. Shah, Ph.D.

The abstracts are published in an online supplement of the journal, Sleep, which is available at https://sleepmeeting.org/wp-content/uploads/2019/04/SLEEP_42_S1-Website-Final.pdf.

REFERENCES:


[i] Colten, H.R., & Altevogt, B.M. (Eds). (2006). Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem.  Institute of Medicine (US) Committee on Sleep Medicine and Research. Washington, DC: National Academies Press (US). doi: https://doi.org/10.17226/11617

[ii] Cappuccio, F.P., D’Elia, L., Strazzullo, P., & Miller, M.A. (2010). Sleep duration and all-cause mortality: A systemic review and meta-analysis of prospective studies. Sleep, 33(5):585-592.

[iii] Watson, N.F., Badr, M.S., Belenky, G., et al. (2015). Joint Consensus Statement of the American Academy of Sleep  Medicine and Sleep Research Society on the Recommended Amount of Sleep for the Healthy Adult, Methodology and Discussion. Journal of Clinical Sleep Medicine, 11(6); 591-592.

[iv] Seiden,D.J., Brodner, D.C., & Shah, S.M. (2018, June 2-6). Improvement in Sleep Maintenance and Sleep Quality with Ion-Powered Pump Continuous Release and Absorption Melatonin: Results from a Self-Reported Patient Outcomes Study (Abstract #0419). Poster presented at SLEEP 2018, Baltimore, Maryland.

[v] Brodner, D.C., Shah, S.M. (2017, June 3-7). REM Absorption Kinetics Trial: A Randomized, Crossover, Pharmacokinetics Evaluation of a Novel Continuous Release and Absorption Melatonin Formulation versus a Same Strength Immediate-Release Formulation in Healthy Adults (Abstract #0396). Poster presented at: SLEEP 2017, Boston, Massachusetts.

[vi] Knutsen, K.L., Turek,, F.W., Patel, S.R., et al (2006). The u-shaped association between sleep and health: the 2 peaks do not mean the same thing.  Comment on Patel, SR, et al. Sleep, 29(7): 878-879.

[vii] Lubetkin,, E.I., & Haomiao, J. (2018). Burden of disease due to sleep duration and sleep problems in the elderly. Sleep Health, 4; 182-187.

[viii] Hafner M, et al. (2017). Why sleep matters-the economic costs of insufficient sleep: A cross-country comparative analysis, Rand Quarterly.

[ix] Ikehara, S, et al. (2009). Association of Sleep Duration with Mortality  from Cardiovascular Disease and other Causes for Japanese Men and Women: the JACC Study. Sleep, 32(3); 295-301.

[x] U.S. Food and Drug Administration. Real World Evidence. Retrieved from https://www.fda.gov/scienceresearch/specialtopics/realworldevidence/default.htm

[xi] U.S. Food and Drug Administration. 21st Century Cures Act. Retrieved from https://www.fda.gov/regulatoryinformation/lawsenforcedbyfda/significantamendmentstothefdcact/21stcenturycuresact/default.htm.

[xii] Colten, H.R., & Altevogt, B.M. (Eds). (2006). Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem.  Institute of Medicine (US) Committee on Sleep Medicine and Research. Washington, DC: National Academies Press (US). doi: https://doi.org/10.17226/11617

[xiii] Cappuccio, F.P., D’Elia, L., Strazzullo, P., & Miller, M.A. (2010). Sleep duration and all-cause mortality: A systemic review and meta-analysis of prospective studies. Sleep, 33(5):585-592.

[xiv] Watson, N.F., Badr, M.S., Belenky, G., et al. (2015). Joint Consensus Statement of the American Academy of Sleep  Medicine and Sleep Research Society on the Recommended Amount of Sleep for the Healthy Adult, Methodology and Discussion. Journal of Clinical Sleep Medicine, 11(6); 591-592.

[xv] European Medicines Agency.(2007). Assessment Report for CIRCADIN.

[xvi] Brodner, D.C. & Shah, S.M. (2017, June 3-7). A Continuous Release Ion Powered Pump Melatonin Delivery System that Overcomes Challenges of Release and Absorption in the Intestines (Abstract #0385). Poster presented at: SLEEP 2017,  Boston, Massachusetts.

SOURCES:

https://finance.yahoo.com/news/significant-real-world-evidence-confirms-123000247.html

Dr. David C. Brodner, Center for Sinus, Allergy, and Sleep Wellness (http://www.brodnermd.com/sleep-hygiene.html)

Other related articles published in this Open Access Online Scientific Journal include the following:

2018

https://pharmaceuticalintelligence.com/2018/06/10/patient-reported-outcomes-study-presented-at-sleep-2018-provides-confirmatory-real-world-evidence-of-the-previously-presented-7-hour-action-of-remfresh-the-first-continuous-release-and-absorp/

2017

https://pharmaceuticalintelligence.com/2017/10/02/2017-nobel-prize-in-physiology-or-medicine-jointly-to-jeffrey-c-hall-michael-rosbash-and-michael-w-young-for-their-discoveries-of-molecular-mechanisms-controlling-the-circadian-rhythm/

https://pharmaceuticalintelligence.com/2017/06/11/ultra-pure-melatonin-product-helps-maintain-sleep-for-up-to-7-hours/

2016

https://pharmaceuticalintelligence.com/2016/03/16/sleep-science/

2013

https://pharmaceuticalintelligence.com/2013/03/09/melatonin-and-its-effect-on-acetylcholinesterase-activity-in-erythrocytes/

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Alteration in Reduced Glutathione level in Red Blood Cells: Role of Melatonin

Author: Shilpa Chakrabarti, PhD

List of abbreviation:
DTNB- 5,5- dithiobis,2-nitrobenzoic acid
t-BHP- Tertiary butyl hydroperoxide
GSH-Reduced glutathione
GSSG- Oxidised glutathione

Objective: The study was taken up to see the effect of melatonin on the alteration of reduced glutathione level in red blood cells.

Pineal melatonin is involved in many physiological functions, the most important among them being sleep promotion and circadian regulation. This pineal product exhibits characteristic diurnal rhythm of synthesis and secretion, which attains its peak at night followed by a gradual decrease during the daytime. Melatonin detoxifies highly toxic hydroxyl and peroxyl radicals in vitro, scavenges hydrochlorous acid, as well as peroxynitrite. It has also been reported to increase the synthesis of glutathione and of several antioxidant enzymes [1].

Method: The present study was undertaken to understand the modulation of intracellular reduced glutathione (GSH) by melatonin in human red blood cells according to the oscillatory circadian changes in levels of this hormone.We have also studied the dose-dependent effect of melatonin on GSH in erythrocytes obtained from blood at two different times, subjected to oxidative stress by incubating with tert-butyl hydroperoxide (t-BHP) [2]. We used t-BHP as pro-oxidant [3]. Erythrocyte GSH was measured following the method of Beutler [4]. The method was based on the ability of the –SH group to reduce 5,5- dithiobis,2-nitrobenzoic acid (DTNB) and form a yellow coloured anionic product whose OD is measured at 412 nm.

A suspension of packed red blood cells in phosphate-buffered saline (PBS) containing glucose was treated with melatonin taken at different concentrations. A stock solution (10mM) of melatonin was prepared in absolute ethanol; further dilutions (100 uM–10 nM) were done with PBS. The concentration of ethanol was alwaysThe in vitro effect of melatonin was evaluated by incubating erythrocytes with melatonin at different doses (10 uM –1 nM final concentration) of melatonin for 30 minutes at 37°C. After washing the erythrocytes with the buffer, to remove any amount of the compound, and finally, packed erythrocytes were used for the assay of GSH. In parallel control experiments, blood was incubated with ethanol (final concentration not more than 0.01% (v/v)) but without melatonin.Oxidative stress was induced in vitro by using tert-butyl hydroperoxide both in presence and absence of melatonin. Use of TBHP is in accordance with the published reports [5].

Results and Discussion: The experiment demonstrated that erythrocyte GSH level increased in nocturnal samples which highlights the role of endogenous melatonin in the circadian changes in cellular glutathione level. Exogenous melatonin demonstrated a protective effect against t-BHP-induced peroxidative damage in both diurnal and nocturnal samples, the effect being more pronounced in aliquots containing very low concentration of melatonin (10 nM – 1 nM) [6]. Melatonin was found to inhibit GSH oxidation in a dose-dependent manner.

Melatonin has been found to upregulate cellular glutathione level to check lipid peroxidation in brain cells [7]. We may say that the incubation of the red cells with melatonin for an extended period (more than 30 minutes) may not have the same effects on the level of glutathione in these cells [12]. Melatonin may act as pro-oxidant in the cells exposed to the indoleamine for longer time. Also, the half-life period of pineal melatonin is for 30 to 60 minutes, as reviewed by Karasek and Winczyk [11].The recycling of glutathione in the cells depends on an NADPH-dependent glutathione enzyme system which includes glutathione peroxidise, glutathione reductase, and γ-glutamyl-cysteine synthase forming a meshwork of an antioxidative system. The stimulatory effect of melatonin on the regulation of the antioxidant enzymes has been reported [8].Since melatonin has an amphiphilic nature, its antioxidative efficiency crosses the cellular membrane barriers in a non-receptor-mediated mechanism. Another explanation of melatonin’s antioxidative activity may be based on its role in the upregulation of some antioxidant enzymes directly. Blanco et al had reported that glutathione reductase and glutathione peroxidase, the major constituents of the glutathione-redox system being stimulated by melatonin [9]. The plasma GSH/GSSG redox state is controlled by multiple processes, which includes synthesis of GSH from its constitutive amino acids, cyclic oxidation and reduction involving GSH peroxidase and GSSG reductase, transport of GSH into the plasma, and the degradation of GSH and GSSG by γ-glutamyltranspeptidase. The increase in erythrocyte GSH concentration after melatonin administration can be related Blanco et al’s report on the known stimulation of γ-glutamylcysteine synthase,a rate-limiting enzyme in reduced glutathione synthesis, by melatonin [10].

Conclusion: On the basis of our study, we may conclude that melatonin affects the glutathione level in red blood cells in a circadian manner. The rhythmic pattern of glutathione level confirms the relationship between physiological melatonin and erythrocyte GSH level and pharmacological dosage of the drug. The role of melatonin as an antioxidant and its activity in relation to these biomarkers has been studied in the above experiments.

Key words: Glutathione, circadian rhythm,, melatonin, biomarkers, oxidative stress

REFERENCES


1. D. Bonnefont-Rousselot and F. Collin, “Melatonin: action as antioxidant and potential applications in human disease and aging,” Toxicology, vol. 278, no. 1, pp. 55–67, 2010. http://www.drvitaminsolutions.com/images/products/Melatonin%20as%20antioxidant%20and%20potential%20applications%20in%20human%20disease%20and%20aging.pdf
2. A. V.Domanski, E. A. Lapshina, and I. B. Zavodnik, “Oxidative processes induced by tert-butyl hydroperoxide in human red blood cells: chemiluminescence studies,” Biochemistry (Moscow), vol. 70, no. 7, pp. 761–769, 2005. http://link.springer.com/article/10.1007%2Fs10541-005-0181-5
3. Z. Cˇervinkova´, P. Krˇiva´kova´, A. La´bajova´ et al., “Mechanisms participating in oxidative damage of isolated rat hepatocytes,” Archives of Toxicology, vol. 83, no. 4, pp. 363–372, 2009. http://www.ncbi.nlm.nih.gov/pubmed/16097939
4. E. Beutler, A Manual of Biochemical Methods, Grunne and Stratton, New York, NY, USA, 1984.
5. P. Di Simplicio, M. G. Cacace, L. Lusini, F. Giannerini, D. Giustarini, and R. Rossi, “Role of protein -SH groups in redox homeostasis—the erythrocyte as a model system,” Archives of Biochemistry and Biophysics, vol. 355, no. 2, pp. 145–152, 1998.
6. S. Chakravarty and S. I. Rizvi., “Day and Night GSH andMDA Levels in Healthy Adults and Effects of Different Doses ofMelatonin on These Parameters” International Journal of Cell Biology, vol. 2011, pp. Article ID 404591.http://www.hindawi.com/journals/ijcb/2011/404591/9CDay+and+Night+GSH+andMDA+Levels+in+Healthy+Adults+and+Effects+of+Different+Doses+ofMelatonin+on+These+Parameters”&gt;
7. S. R. Pandi-Perumal, V. Srinivasan, G. J. M. Maestroni, D. P. Cardinali, B. Poeggeler, and R. Hardeland, “Melatonin: nature’s most versatile biological signal?” FEBS Journal, vol. 273, no. 13, pp. 2813–2838, 2006.http://onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2006.05322.x/full
8. R. J. Reiter, R. C. Carneiro, and C. S. Oh, “Melatonin in relation to cellular antioxidative defense mechanisms,” Hormone and Metabolic Research, vol. 29, no. 8, pp. 363–372, 1997.http://www.ncbi.nlm.nih.gov/pubmed/9288572
9. Y.Urata, S.Honma, S. Goto et al., “Melatonin induces gammaglutamylcysteine synthetase mediated by activator protein-1in human vascular endothelial cells,” Free Radical Biology and Medicine, vol. 27, no. 1-2, pp. 838–847, 1997.http://www.ncbi.nlm.nih.gov/pubmed/10515588
10. R. A. Blanco, T. R. Ziegler, B. A. Carlson et al., “Diurnal variation in glutathione and cysteine redox states in human plasma,” American Journal of Clinical Nutrition, vol. 86, no. 4, pp. 1016–1023, 2007. http://www.ncbi.nlm.nih.gov/pubmed/17921379
11. M. Karasek, K. Winczyk, “Melatonin in humans,” Journal of Phsiology and Pharmacology, vol. 57, no. 5, pp. 19-39, 2006. http://www.jpp.krakow.pl/journal/archive/11_06_s5/articles/02_article.html
12. A. Krokosz ,J. Grebowski, Z. Szweda-Lewandowska et al., ” Can melatonin delay oxidative damage of human
erythrocytes during prolonged incubation?” Advances in Medical Sciences, vol. 58, no. 1, 2013.http://www.researchgate.net/publication/236614971_Can_melatonin_delay_oxidative_damage_of_human_erythrocytes_during_prolonged_incubation

 

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Melatonin and its effect on acetylcholinesterase activity in erythrocytes

Author: S. Chakravarty, PhD

 

Objective: The study was conducted to see the effect of melatonin on the activity of acetylcholinesterase in red blood cells.

Mammalian red blood cells contain membrane-bound acetylcholinesterase which acts as biomarkers of oxidative imbalance. Melatonin is a powerful free radical scavenger and upregulates several antioxidant enzymes to reduce oxidative stress. Being an effective antioxidant, it may initiate variation in erythrocyte acetylcholinesterase activity.

The study was carried out on twenty-nine subjects of both sexes who gave their informed consent for the use of their blood samples for the study (Chakravarty and Rizvi, 2011a). The red cells isolated from blood collected at two different timings of the day, viz., 10:00 a.m. and 10:00 p.m.,were subjected to in vitro treatment with melatonin in a dose-dependant manner followed by the assay of enzyme activity (Ellman et al., 1961).

Acetylcholinesterase (AChE) is also found on the red blood cell membranes, where it constitutes the Yt blood group of antigen, which is a blood-group determining protein. AChE has the features of a secreted rather than a transmembrane protein because it lacks long hydrophobic stretches, other than that which forms the signal peptide (Li et al., 1991). Besides, acetylcholinesterase activity in erythrocytes may be considered as a marker of central cholinergic status (Kaizer et al., 2008). AChE shows highest activity in the immature rat brain is at 6.00 a.m. and lowest after midnight, which undergoes a reversal after attaining maturity (Moudgil and Kanungo, 1973). The enzyme also exhibits annual changes in its activity (Lewandowski, 2008). Acetylcholinesterase activity has been used to for studying the activity pattern of human erythrocytes (Prall et al., 1998). Free radicals and increased oxidative stress have been found to reduce AChE activity (Molochkina et al., 2005). This indicates that melatonin may have some relation with the circadian rhythmicity of acetylcholinesterase activity.

The concentration-dependant assay of AChE activity in red cells bear close relation with the circadian rhythm in humans thus sharing a similar conclusion with that mentioned by Moudgil and Kanungo (Moudgil and Kanungo, 1973). The effect of melatonin on enzyme functions in erythrocytes follows rhythmic modulation with day/night cycle. The samples obtained in the morning exhibit significantly higher activity of acetylcholinesterase than those obtained during the night-time. The samples collected at two different timings of the day show different response to in vitro melatonin treatment. The rise in AChE activity is more pronounced at low doses of melatonin. Our results indicate significant increase in acetylcholinesterase activity in diurnal as well as nocturnal blood samples at different concentrations of exogenous melatonin (Rizvi and Chakravarty, 2011). At supraphysiological doses, the enzyme activity exhibits no significant change, owing to the prooxidative influence exerted by melatonin (Marchiafava and Longoni, 1999).

Acetylcholinesterase activity is affected by the hydrophobic environment of the cell membrane and depends on the plasma membrane fluidity and surface charge of the cell (Klajnert et al., 2004).  The activity of AChE depends largely on the biophysical features of membrane. Oxidative stress decreases the fluidity of membrane lipid bilayer, thus affecting its normal functions (Goi et al., 2005).  Such are the ill-effects of oxidative radicals that tend to increase with aging. The decrease in AChE correlates significantly with age-induced oxidative stress (Jha and Rizvi, 2009).  On the basis of our study we conclude that melatonin modulates acetylcholinesterase activity in erythrocytes. The rhythmicity observed in the activity of acetylcholinesterase in response to the melatonin confirms our opinion on the relationship between the enzyme function, pineal secretion and pharmacological dosage of the indole antioxidant.

References:

  1. Chakravarty S, Rizvi SI, Circadian modulation of sodium-potassium ATPase and sodium-proton exchanger in human erythrocytes: in vitro effect of melatonin. <a href=”80-6. “http://www.ncbi.nlm.nih.gov/pubmed/21366966
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Day and Night Variation in Melatonin Level affects Plasma Membrane Redox System in Red Blood Cells

Author: Shilpa Chakravarty, PhD

Melatonin is a well-established antioxidant and sleep-regulating hormone. Over the past fifty years, its efficiency as a regulator of circadian rhythm and several other physiological functions has been studied extensively in different species. As a free-radical scavenger, melatonin has shown its activity in coordination with its circadian nature. One of the most important biomarkers of oxidative stress studied in red blood cells is the plasma membrane redox system (PMRS).

As a part of the research activity, PMRS activity has been summarised in this article. The experiments with PMRS and ascorbate free-radical reductase (AFR reductase) have been conducted in vitro.

The study was carried out on 61 healthy individuals of both sexes (aged 20-30) having no acute or chronic diseases (such as diabetes mellitus, asthma, or tuberculosis) or any organ dysfunction and had not taken any medication. Blood samples were collected at two different timings at 10:00AM and 10:00PM.  Red blood cell-membrane, was in retrospect a good experimental system to try to extract and isolate membrane proteins for biochemical assays. Two factors that have favoured it for experimental use are availability and simplicity. Results from its study have been replicated in every other mammalian cell type, and in some crucial points, the patterns shown by RBC
proteins have led the way to such interpretations of extensive physiological studies.

PMRS transfers electrons from extracellular substates to intracellular electron acceptors incorporating AFR reductase. An increase in PMRS activity indicates the ability of the cell to combat oxidative damage.The aging of human red cells may well be attributed to free radical induced oxidative damage. Maintenance of redox state of sulphydryl residues and reduction of lipid hydroperoxides at the expense of electron donors, such as ascorbate and NADH, is essential for normal energy metabolism in the cell. The neutralisation of oxidants also involves some membrane proteins that comprise the PMRS. The rise in PMRS activity is required to maintain a balanced NAD+/NADH ratio that is essential for normal energy metabolism. It leads to cell survival and membrane homeostasis under stress conditions and during calorie restriction in eukaryotes. The day and night variation in PMRS activity shows that the antioxidative behaviour of melatonin is also influenced by its circadian mode of action. While melatonin is an effective antioxidant against cellular toxicity, it also increases the PMRS activity in red blood cells at night. During the day, when the pineal secretion is low, the PMRS activity is also suppressed.

However, if subjected to in vitro treatment with melatonin, at such a concentration that lies close to the maximal melatonin level in the plasma (maximal secretion of melatonin occurs during the scotopic phase of the day), PMRS increases in red blood cells. This shows that the circadian nature of the hormone not only pertains to its pineal production but also to exogenous administration of the drug.

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