Melatonin is a hormone produced in the pineal gland that regulates sleep cycles. It is secreted at night in response to darkness and suppresses in the morning in response to light. As an antioxidant, it plays a role in reducing oxidative stress and protecting nuclear and mitochondrial DNA. Therapeutically, melatonin is used to treat cancer, immune disorders, cardiovascular diseases, depression, and sleep disorders. Low melatonin levels can be caused by factors like alcohol, caffeine, medications, stress, and cigarettes. While melatonin supplements have benefits, high doses can cause side effects like nausea, vivid dreams, and drowsiness.
Melatonin is a hormone made in the body. It regulates night and day cycles or sleep-wake cycles. Melatonin in supplements is usually made in a lab.
Darkness triggers the body to make more melatonin, which signals the body to sleep. Light decreases melatonin production and signals the body to be awake. Some people who have trouble sleeping have low levels of melatonin. It's thought that adding melatonin from supplements might help them sleep.
Melatonin is a hormone made in the body. It regulates night and day cycles or sleep-wake cycles. Melatonin in supplements is usually made in a lab.
Darkness triggers the body to make more melatonin, which signals the body to sleep. Light decreases melatonin production and signals the body to be awake. Some people who have trouble sleeping have low levels of melatonin. It's thought that adding melatonin from supplements might help them sleep.
Globally 14.2 million people - 30-69 years old die / year from the modern Lifestyle Diseases.These diseases emerged as bigger killers than infectious or hereditary ones. Orthopaedic complaints accounts for the epidemic proportions (cases of low back ache, joint disorders, degenerative diseases that we find in our clinics and also around us). Lack of proper sleep and the continuous exposure to Blue light from television, PC and laptop screens are of the sources of the worst blue lights one can be exposed to and by leaving a television set or laptop screen on during the night will suppress melatonin production significantly. Melatonin is distributed widely in nature; it acts as a photoperiod messenger molecule, transducing photoperiod changes to various cyclic function (reproduction, sleep-wake rhythms). Melatonin is very important antioxidant . Melatonin influences various cell mechanisms . We have to know how to Improve and Protect our Melatonin Production by Improving our sleep hygiene.
Melatonin Transcription:
Melatonin controls the circadian rhythm as well as the deep stages of sleep.
Melatonin is produced by the pineal gland and declines significantly when a person reaches age 40.
Melatonin levels peak at night and decrease throughout the day with the help of natural sunlight.
The essential amino acid (tryptophan) from which melatonin is derived helps to regulate your circadian sleep rhythm.
Melatonin is considered a super antioxidant due to its ability to cross the blood-brain barrier.
Melatonin also works with cholecystokinin in the digestive tract to decrease the likelihood and severity of many symptoms associated with gastric ulcers and colitis.
Your melatonin levels will naturally decrease with age. This is why some older people will sleep less even though they still need the same amount of sleep.
Cortisol (the stress hormone) is partially regulated by melatonin.
Culprits of Low Melatonin Levels:
Alcohol
Vitamin B12
Caffeine
NSAID anti-inflammatory medication
Beta-blocker medication
Glucocorticoid medication
Cigarettes
Antidepressants
Frequent stress
Melatonin is a natural substance that should be taken at night. It is not addictive or habit forming.
Sleep Facts:
New parents lose 400-750 hours of sleep during their newborn’s first year.
The number of car accidents decreases in Canada during daylight savings.
Constant access to the internet is one of the biggest contributors to lack of sleep.
Ducks are able to keep one half of their brain awake, while the other half is asleep, in order to survive predator attacks.
http://vitalitmed.com/hormones/melatonin/
Melatonin is produced by the pineal gland from the essential amino acid L-tryptophan and declines significantly when a person reaches age 40. Melatonin also controls the circadian rhythm as well as deep stages of sleep. Learn more about this powerful sleep hormone and its benefits.
Globally 14.2 million people - 30-69 years old die / year from the modern Lifestyle Diseases.These diseases emerged as bigger killers than infectious or hereditary ones. Orthopaedic complaints accounts for the epidemic proportions (cases of low back ache, joint disorders, degenerative diseases that we find in our clinics and also around us). Lack of proper sleep and the continuous exposure to Blue light from television, PC and laptop screens are of the sources of the worst blue lights one can be exposed to and by leaving a television set or laptop screen on during the night will suppress melatonin production significantly. Melatonin is distributed widely in nature; it acts as a photoperiod messenger molecule, transducing photoperiod changes to various cyclic function (reproduction, sleep-wake rhythms). Melatonin is very important antioxidant . Melatonin influences various cell mechanisms . We have to know how to Improve and Protect our Melatonin Production by Improving our sleep hygiene.
Melatonin Transcription:
Melatonin controls the circadian rhythm as well as the deep stages of sleep.
Melatonin is produced by the pineal gland and declines significantly when a person reaches age 40.
Melatonin levels peak at night and decrease throughout the day with the help of natural sunlight.
The essential amino acid (tryptophan) from which melatonin is derived helps to regulate your circadian sleep rhythm.
Melatonin is considered a super antioxidant due to its ability to cross the blood-brain barrier.
Melatonin also works with cholecystokinin in the digestive tract to decrease the likelihood and severity of many symptoms associated with gastric ulcers and colitis.
Your melatonin levels will naturally decrease with age. This is why some older people will sleep less even though they still need the same amount of sleep.
Cortisol (the stress hormone) is partially regulated by melatonin.
Culprits of Low Melatonin Levels:
Alcohol
Vitamin B12
Caffeine
NSAID anti-inflammatory medication
Beta-blocker medication
Glucocorticoid medication
Cigarettes
Antidepressants
Frequent stress
Melatonin is a natural substance that should be taken at night. It is not addictive or habit forming.
Sleep Facts:
New parents lose 400-750 hours of sleep during their newborn’s first year.
The number of car accidents decreases in Canada during daylight savings.
Constant access to the internet is one of the biggest contributors to lack of sleep.
Ducks are able to keep one half of their brain awake, while the other half is asleep, in order to survive predator attacks.
http://vitalitmed.com/hormones/melatonin/
Melatonin is produced by the pineal gland from the essential amino acid L-tryptophan and declines significantly when a person reaches age 40. Melatonin also controls the circadian rhythm as well as deep stages of sleep. Learn more about this powerful sleep hormone and its benefits.
Tryptophan is first hydroxylated to form 5-OH-tryptophan in liver. The reaction is analogous to conversion of Phe - to tyrosine. Liver phenyl alanine hydroxylase also can catalyse hydroxylation of tryptophan. In the next step, 5-OH-tryptophan is decarboxylated, by the enzyme 5-OH-tryptophan decarboxylase, in presence of B6-PO4 to form 5-hydroxy tryptamine (5-HT), also called serotonin. The enzyme is present in kidney, liver and stomach. Aromatic-Lamino acid decarboxylase, widely distributed in tissues can also catalyse this reaction.
Melatonin supplements are most usually taken as a tranquilizer, however as per research, it might have other constructive outcomes on the body. In its normal state, melatonin is discharged by an organ in our mind and directs a cycle called the circadian musicality.
1-ENDOCRINOLOGY-Part-I.PPT PART OF THE HUMAN BODYbarilloanfhal
What Is Endocrinology?
The Basics
Endocrinology is a branch of medicine that deals with the endocrine system, which controls the hormones in your body. An endocrinologist is a physician who specializes in the field of endocrinology. Endocrinologists diagnose and treat a wide range of conditions affecting the endocrine system, including diabetes mellitus, thyroid disorders, osteoporosis, growth hormone deficiency, infertility, cholesterol problems, hypertension (high blood pressure), obesity and more.
How the Endocrine System Works
The endocrine system’s glands and organs release hormones that regulate a number of vital functions of our body. These glands include the hypothalamus, pineal body, pituitary, thyroid, parathyroids, adrenals, pancreas, testes and ovaries.
The hormones in your body all have specific jobs to complete. There are up to 40 different hormones circulating in your blood at any time. Once released into the bloodstream, a hormone travels throughout the body until it reaches its specific destination(s) to perform its function. These destinations, called targets, can be located either on other endocrine glands or on other organs and tissues in the body.
When a hormone reaches its target, it tells that part of your body what work to do, when to do it and for how long. Hormones are often referred to as the “messengers” because they help different parts of the body communicate. Overall, they are involved in many different processes in the body, including:
Blood sugar control
Growth and development
Metabolism (the process of getting and maintaining energy in the body)
Regulation of heart rate and blood pressure
Sexual development and function
Reproduction
Mood
What Happens When the Endocrine System Does Not Work?
Hormonal function is a balancing act. Too much or too little of one hormone can have an impact on the release of other hormones. If this hormonal imbalance occurs, some of your body’s systems will not work properly.
These imbalances can often be corrected by the body itself. Your body has built-in mechanisms to keep track of and respond to any changes in hormone levels to bring them back to normal and restore the balance.
Sometimes, however, this system goes wrong and there can be a problem that the body can’t fix itself. In this case, a primary care physician will refer you to an endocrinologist, who is an expert in treating frequently complex (and often chronic) conditions which can involve several different systems within the body.
The Anatomy of the Endocrine System
The endocrine system is made up of a collection of glands. Each gland has a specific function in the body, and all these glands work together to regulate vital functions of our body.
Adrenal glands
Located just above the kidneys, adrenal glands are responsible for the secretion of several hormones which maintain the body’s salt and water balance that in turn regulate blood pressure, help the body cope with and respond to stress, regulate body meta
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These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
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Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
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3. Melatonin
Arone Lerner was discovered this hormone in 1958.
Melatonin also known chemically as N-acetyl-5
methoxytryptamine.
It is a naturally occuring compound found in all living
creatures from algae to humans at levels that vary in
daily cycles.
It is known as “Hormone of darkness”.
it is secreted in darkness in both day-active (diurnal) and
night-active (nocturnal).
Many biological effects of melatonin are produced
through activation of Melatonin receptors.
5. Production:
In higher animals, melatonin is produced by pinealocytes in
the pineal gland (located in the brain) and also by the
retina , lens and GI tract.
It is naturally synthesized from the amino acid tryptophan
Melatonin produced in the pineal gland acts as an
endocrine hormone since it is released into the blood.
By contrast, melatonin produced by the retina and the
gastrointestinal (GI) tract acts as a paracrine hormone.
production of melatonin by the pineal gland is under the
influence of the suprachiasmatic nucleus (SCN) of the
hypothalamus which receives information from the retina
about the daily pattern of light and darkness.
6. Contd…………
The light/dark information reaches the SCN via
the inner retinal ganglion cells which are
intrinsically photosensitive ,photoreceptor cells
those involved in the visual system.
These cells represent approximately 2% of retinal
ganglion cells in humans and express the non-
visual photo pigment Melanopsin.
The sensitivity of melanopsin fits with that of a
vitamin A based photo pigment with a peak
sensitivity at 484 nm (blue light)
7. Contd………..
This photoperiod cue entrains the circadian
rhythm, and the resultant production of specific
“dark” and “ light” induced neural and endocrine
signals regulates behavioral and physiological
circadian rhythms.
Melatonin may also be produced by a variety of
peripheral cells such as bone marrow cells
lymphocytes and epithelial cells.
Usually, the melatonin concentration in these cells
is much higher than that found in the blood but it
does not seem to be regulated by the photoperiod.
8.
9. Role of the SCN in the Sleep-Wake cycle
During the day, the SCN
emits an alerting signal
that helps maintain
Wakefulness.
At night, the alerting
signal is attenuated,
facilitating the onset
of sleep.
10. Secretion:
Melatonin secretion starts at 3-4 months of age.
Peak levels at 1-3 years of age.
Slightly lower levels through early adulthood.
Peak levels for 70 year old is ¼ of levels for young adult.
Metabolism:
Liver is the 1st site for metabolism & clears >90% of
circulation melatonin.
Melatonin is 1st hydroxylated then excreted in urine as
sulphate & glucoronide conjugates.
About 1 % of melatonin remains unchanged in urine.
11. Melatonin receptors:
Found in central nervous system and peripheral
Tissues.
In brain MT1 and MT2 receptors are found in
membranes of neurons of (SCN).
MTI and MT2 are G - protein-couple receptors.
MT3 receptor is also found which is poorly
understood.
12. MT1 Agonists
Promote sleep via MT1
Receptor in SCNregulating
Sleep/wake cycle
Physiological Sleep
MT1
Sleep promotion
Melatonin receptor agonist
15. Melatonin in Animals:
Melatonin can suppress libido by inhibiting secretion of
(LH) and (FSH) especially in mammals that have a
breeding season when daylight hours are long.
The reproduction of long-day breeders is repressed by
melatonin and the reproduction of short-day breeders is
stimulated by melatonin.
In animals ,circulating levels of the hormone melatonin vary
in a daily cycle.
During the night, melatonin regulates leptin lowering
the levels.
16. Melatonin in Humans:
The melatonin signal forms part of the system that
regulates the sleep-wake cycle.
Infants melatonin levels become regular in about the
third month after birth, with the highest levels
measured between midnight and (8 AM).
In humans, 90% of melatonin is cleared through the
liver, a small amount is excreted in urine and a small
amount is found in saliva.
17. Light dependence:
Production of melatonin is inhibited by light and
permitted by darkness. SO called "the hormone of
darkness“.
Its onset called the Dim-Light Melatonin Onset
(DLMO).
Secretion in blood peaks in the middle of the night, and
gradually falls during the second half of the night, with
normal variations in timing according to an individual's
chronotype.
It is principally blue light, around 460 to 480nm that
suppresses melatonin.
Use of blue-blocking goggles the last hours before
bedtime advised for people who need to adjust to an
earlier bedtime, as melatonin promotes sleepiness.
18. Physiological role of melatonin:
Antioxidant
Immune system
Cancer
Dreaming
Sleep
Menstrual Benefits
Other
19. Anti- oxidant action of melatonin:
1.Direct anti-oxidant actions
Free radical scavenger of ROS
Free radical scavenger of RNS
2.In direct anti-oxidant actions
Stimulation of anti-oxidant enzymes
Stimulation of synthesis of glutathione
Synergistic actions of melatonin with
classical anti-oxidants
20. Melatonin as a scavenger of ROS:
Melatonin scavenger of Hydroxyl radical (OH):
Each molecule of melatonin scavengers 2 OH radicals.
Cyclic 3-Hydroxy melatonin itself has free radical
scavenging action and it is foot print molecule that
appears in urine.
Melatonin scavenger of superoxide(O2
- .
)
Melatonin scavenger O2
- .
in a pure chemical system
where a hypoxanthine/ xanthine system was used to
produce O2
- .
21. Melatonin scavenger of H2O2:
Melatonin is scavenger of H2O2 in a pure chemical
system.
A mechanism of the oxidation of melatonin by H2O2
was suggested on the basis of two major resulting
metabolite i.e., N- Acetyl-N-Formyl-5-Methoxy
kynuranine(AFMK)
Cyclic 3- hydroxy melatonin & AFMK function as
scavenger of toxic reactants as like as parent molecule
(i.e,Melatonin).
22. Melatonin scavenger of singlet oxygen:
Melatonin neutralizer singlet O2 during which AFMK
was generated i.e., AFMK was the product when
melatonin was oxidized by singlet oxygen.
Melatonin scavenger of initiating agents of lipid
peroxidation.
Melatonin is highly efficient in limiting the
peroxidation of lipids. It is due to scavenging of
initiating agents(.OH,NOO-) rather than direct LOO.
scavenger.
23. Melatonin Scavenger of RNS:
Melatonin interacts with NO
.
only in the presence of
molecule oxygen.
The chief product of melatonin /NO
.
reaction is N-
nitromelatonin.
Indirect antioxidant actions of melatonin:
1.Melatonin stimulation of glutathione:
It stimulates the rate limiting enzyme
γ-Glutanylcysteine synthase,there increasing intracellular
GSH conc.
This action of melatonin ,unlike direct free radical
scavenging function of the indoleamine is likely mediated
by specific receptors.
The stimulation of GSH synthesis by melatonin could be a
major antioxidative action of melatonin.
24. Melatonin stimulation of antioxidant enzymes:
Melatonin stimulates GPx ,GR. The ability of melatonin
to regulate GSH by modulating enzyme activates appears
to involve an actions of melatonin at nuclear binding
site.
The other GSH metabolizing enzyme i.e., catalase also
increases it’s activity on response to melatonin.
GR requires the cofactor NADPH which is generated by
the antioxidant enzymes G-6-phosphate
dehydrogenase(G6PD).Melatonin also stimulates G6PD.
Melatonin enhances gene expression for antioxidant
enzymes either under base conditions or after their
inhibition by neurotonic agents.
25. Synergistic action of melatonin with classical
antioxidants:
Melatonin important actions at the level of
mitochondria are:
It is efficient scavenger of ROS/RNS which are
abundant in mitochondria.
Although mitochondria are incapable of GSH
synthesis they posses GPx &GR for GSH cyclins ,
both enzymes of which are stimulated by
melatonin.
Melatonin has anti-apoptotic effects against
apoptic signals originating in mitochondria.
Melatonin may be in higher conc. in
mitochondria than in the cell.
26.
27. Other roles of melatonin as Antioxidant:
It is extremely powerful antioxidant with a particular
role in the protection of nuclear and mitochondrial
DNA
Melatonin that can protect against cancer by
eliminating free radicals.
It does this by activating the cytokine system
(lymphocytic function).
28. Contd…………….
Melatonin is a direct scavenger of OH, and NO.
Melatonin once oxidized cannot be reduced to its
former state because it forms several stable end
products upon reacting with free radicals Called
terminal or suicidal antioxidant.
The antioxidant activity of melatonin may reduce
damage caused by some types of Parkinson's
disease may play a role in preventing cardiac
arrhythmia.
29. Melatonin in Immune System:
Immunological effect is thought to result from
melatonin acting on high affinity receptors (MT1
and MT2).
Melatonin may enhance cytokine production.
Melatonin might be useful fighting infectious
disease including viral, such as HIV and bacterial
infections , and cancer.
Endogenous melatonin in human lymphocytes has
been related to interleukin-2 (IL-2) production.
30. Cancer:
Melatonin has also been thought to fight against
cancer (especially prostate, breast and colon cancers).
Melatonin is inhibitory action of tumor growth.
The apparent melatonin induced suppression of
prolactin , when prolactin is a hormone that can
promote mammary cancer .
Several studies reported that , during the initial state
of tumor development , melatonin is increased an
early stage of cancer with malignant cells that do not
growth.
31. Melatonin in Dream:
Increase in vivid dreaming or frequency of dreams.
Extremely high doses of melatonin (50 mg) increased
REM sleep time and dream activity in both
narcoleptics and those without narcolepsy
80mg can induce sleep in adults.
Many drugs such as cannabis ,cocaine increase
melatonin synthesis.
Sleep:
Melatonin is “opening the sleep gate”
SCN is the site of internal biological clock.
Elevated melatonin level occur at night coincident
with sleep.
32. Melatonin’s Digestive Powers:
Melatonin works with cholecystokinin in the
digestive tract to decrease the likelihood and severity
of many symptoms associated with gastric ulcers
and colitis.
Menstrual Benefits:
When estradiol is administered to postmenopausal
women, their melatonin levels increase.
This occurs naturally throughout a woman’s life
before she reaches menopause, having a positive
effect on women’s menstrual cycles.
33. Other Functions:
Exogenous melatonin decreases leptin production.
Reported that melatonin intake reduced BP during
sleep, without effect of the heart rate.
One of the claimed action of melatonin that anti aging
effect.
Melatonin controls the circadian rhythm as well as
deep stages of sleep.
It increasing secretion of GnRH and sex hormones.
Inhibits growth and development of sex organs before
puberty.
Many biological effects of melatonin are produced
through activation of melatonin receptors.
34. Therapeutic uses:
Melatonin is used in the treatment of
Cancer
Immune disorders
Cardiovascular diseases
Depression
Seasonal effective sleep disorders
Sexual dysfunction
Fertility
Headache
Used as dietary supplement
Used to Prevent ischemic damage
36. Adverse Effects:
• Some unwanted effects in some people especially
at high doses(3mg/day or more).
Nausea
Vivid dreams or night mares
Reduced blood flow
Hypothermia
Hormone fluctuations
Drowsiness , Dizziness
Confusion , Hallucinations
Fatigue
Menstrual irregularities
37. Recommended dose of melatonin:
For most uses doses ranging from 0.3 to 5 mg once
daily (usually in the evening) seem to work well.
Some of the marketed products:
38. Summary:
Finally when melatonin secretes it leads to sleep.
Melatonin levels maintain the biological clock.
It used to treat the cancer at early stages.
It controls the BP and cardiac rhythm during sleep.
It reduce damage in case of Parkinson's disease.
It plays a particular role in the protection
of nuclear and mitochondrial DNA.
Melatonin has also been found to help protect your
brain in the event of a traumatic brain injury.
39. References:
http://www.drugs.com/melatonin.html
Lewis, Alan (1999). Melatonin and the Biological Clock.
McGraw-Hill.
Hardeland R (2005). "Antioxidative protection by
melatonin: multiplicity of mechanisms from radical
detoxification to radical avoidance.". Endocrine .
Foundations of nutrition by bhavana sabarwal.
Rieter,J.R. The pineal gland and melatonin in relation to
aging; a summary of the theories and the
data.Exp.Gerontol. 30:199-212.
Ross and Wilson Anatomy and physiology in health
and illness.