Article

Harmful effects of nicotine

Abstract

With the advent of nicotine replacement therapy, the consumption of the nicotine is on the rise. Nicotine is considered to be a safer alternative of tobacco. The IARC monograph has not included nicotine as a carcinogen. However there are various studies which show otherwise. We undertook this review to specifically evaluate the effects of nicotine on the various organ systems. A computer aided search of the Medline and PubMed database was done using a combination of the keywords. All the animal and human studies investigating only the role of nicotine were included. Nicotine poses several health hazards. There is an increased risk of cardiovascular, respiratory, gastrointestinal disorders. There is decreased immune response and it also poses ill impacts on the reproductive health. It affects the cell proliferation, oxidative stress, apoptosis, DNA mutation by various mechanisms which leads to cancer. It also affects the tumor proliferation and metastasis and causes resistance to chemo and radio therapeutic agents. The use of nicotine needs regulation. The sale of nicotine should be under supervision of trained medical personnel.
24 Indian Journal of Medical and Paediatric Oncology | Jan-Mar 2015 | Vol 36 | Issue 1
Harmful effects of nicotine
preparation that deliver around 1 mg and 3 mg nicotine to
the blood stream respectively. E-cigarette, a sophisticated
nicotine delivery device, delivers nicotine in a vapor form
and it closely mimics the act of smoking. Currently, these
products constitute approximately 1% of total nicotine
consumption and are showing an increasing trend in most
countries.[3]
Nicotine is well known to have serious systemic side effects
in addition to being highly addictive. It adversely affects the
heart, reproductive system, lung, kidney etc. Many studies
have consistently demonstrated its carcinogenic potential.
[Table 1] The only other known use of nicotine has been
as an insecticide since 17th century.[4] After World War II,
its use has declined owing to the availability of cheaper,
more potent pesticides that are less harmful to mammals.
The environment Protection Agency of United States
has banned use of nicotine as a pesticide from 1st January
2014.[4] India, one of the largest producer and exporter
of nicotine sulphate, has progressively banned its use
as agricultural pesticide.[5] We undertook this review to
evaluate the systemic adverse effects of nicotine.
MATERIALS AND METHODS
A computer aided search of the Medline and PubMed
databases was done using different combination of the
keywords “nicotine,” “chemical composition,” “history,”
“metabolism,” “addiction,” “cancer,” “toxic,” “endocrine
system,” “cardiovascular system,” “respiratory system,”
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DOI:
10.4103/0971-5851.151771
Aseem Mishra,
Pankaj Chaturvedi,
Sourav Datta, Snita Sinukumar,
Poonam Joshi, Apurva Garg
Department of Surgical Oncology,
Head and Neck Services, Tata
Memorial Hospital, Parel, Mumbai,
Maharashtra, India
Address for correspondence:
Dr. Pankaj Chaturvedi,
Professor, Department of
Surgical Oncology, Head and
Neck Services, Tata Memorial
Hospital, Dr. E. Borges Road,
Parel, Mumbai - 400 012,
Maharashtra, India.
E-mail: chaturvedi.pankaj@gmail.com
ABSTRACT
With the advent of nicotine replacement therapy, the consumption of the nicotine
is on the rise. Nicotine is considered to be a safer alternative of tobacco. The IARC
monograph has not included nicotine as a carcinogen. However there are various
studies which show otherwise. We undertook this review to specically evaluate the
effects of nicotine on the various organ systems. A computer aided search of the
Medline and PubMed database was done using a combination of the keywords. All
the animal and human studies investigating only the role of nicotine were included.
Nicotine poses several health hazards. There is an increased risk of cardiovascular,
respiratory, gastrointestinal disorders. There is decreased immune response and it also
poses ill impacts on the reproductive health. It affects the cell proliferation, oxidative
stress, apoptosis, DNA mutation by various mechanisms which leads to cancer. It also
affects the tumor proliferation and metastasis and causes resistance to chemo and radio
therapeutic agents. The use of nicotine needs regulation. The sale of nicotine should
be under supervision of trained medical personnel.
Key words: Addiction, cancer, cardiovascular, gastrointestinal, nicotine, respiratory
INTRODUCTION
Tobacco is the leading cause of preventable cancers.
WHO estimated around 1.27 billion tobacco users world-
wide. Tobacco consumption alone accounts for nearly 5.4
million deaths per year and one billion people may die in
this century if global tobacco consumption remained at
the current levels.[1] An international treaty spearheaded
by WHO in 2003 and signed by 170 countries, aims to
encourage governments to reduce the production, sales,
distribution advertisement and promotion of tobacco
products. Despite strong opposition from the Industry,
the treaty has been making steady progress in achieving
its goal of comprehensive tobacco control around the
world.[2] As tobacco consumption is being curbed, there
is a growing demand for cessation. Pharmacological
treatment of nicotine addiction remains an active area of
research. There are many nicotine preparations (nicotine
gums, patches, e cigarettes and inhalational agents) that are
freely available in most parts of the world. These products
are being heavily promoted and marketed as magical
remedies. Nicotine gums are available in 2 mg and 4 mg
REVIEW ARTICLE
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Mishra, et al.: Harmful effects of nicotine
Indian Journal of Medical and Paediatric Oncology | Jan-Mar 2015 | Vol 36 | Issue 1 25
“lung carcinogenesis, “gastrointestinal system,” “immune
system,” “ocular,” “ cataract,” “central nervous system,”
“renal system,” “ reproductive system,” “menstrual cycle,”
“oocytes,” “foetus,”. Initial search buildup was done using
“Nicotine/adverse effects” [Mesh], which showed 3436
articles. Articles were analyzed and 90 relevant articles were
included in the review. All the animal and human studies
that investigated the role of nicotine on organ systems
were analyzed. Studies that evaluated tobacco use and
smoking were excluded. All possible physiological effects
were considered for this review. We did not exclude studies
that reported benecial effects of nicotine. The objective
was to look at the effects of nicotine without confounding
effects of other toxins and carcinogens present in tobacco
or tobacco smoke.
CHEMICAL PROPERTIES AND METABOLISM
Nicotine was rst extracted from tobacco by German
physicians Wilhelm Heinrich Posselt and Karl Ludwig
Reimann. Nicotine, a strong alkaloid, in its pure form is
a clear liquid with a characteristic odour. It turns brown
on exposure to air. It is water soluble and separates
preferentially from organic solvents. It is an amine
composed of pyridine and pyrrolidine rings.
Nicotine is a dibasic compound and the availability and
absorption in human body depends upon the pH of the
solution.[7] The absorption can occur through oral mucosa,
lungs, skin or gut.[6] The increase in pH of a solution causes
an increase in concentrations of uncharged lipophilic
nicotine, in this form it can actively pass through all
biological membranes.[7] The addition of slaked lime and
catechu to tobacco increases the absorption of nicotine
from the oral cavity.
Nicotine once ingested, is absorbed and metabolized
by the liver. The metabolic process can be categorized
into two phases. In phase I there is microsomal
oxidation of the nicotine via multiple pathways.[8] This
leads to formation of various metabolites like cotinine
and nornicotine, demethyl cotinine, trans-3-hydroxy-
cotinine and d-(3-pyridyl)-g-methylaminobutyric acid.[9,10]
Thereafter in phase II there is N’-and O’-glucuronidation
of the metabolites and excretion via urine, feces, bile,
saliva, sweat etc.[11,12] 5-10% of elimination is by renal
excretion of unchanged nicotine, however there is
reabsorption from the bladder when the urinary pH is
high.[14] There is evidence that nitrosation of nicotine
in vivo could lead to formation of N-nitrosonornicotine
(NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-
butanone (NNK).[13] which are known to be highly
carcinogenic. Inammation in the oral cavity increases
risk of endogenous nitrosation.
MECHANISM OF ACTION
Nicotine acts via 3 major mechanisms, producing
physiological and pathological effects on a variety of organ
systems.[15,16]
1. Ganglionic transmission.
2. Nicotinic acetylcholine receptors (nAChRs) on
chromafn cells via catecholamines.
3. Central nervous system (CNS) stimulation of nAChRs.
Brain imaging studies demonstrate that nicotine acutely
increases activity in the prefrontal cortex and visual
systems. There is release of a variety of neurotransmitters
important in drug-induced reward. Nicotine also causes an
increased oxidative stress and neuronal apoptosis, DNA
damage, reactive oxygen species and lipid peroxide increase.
nAChRs were originally thought to be limited to neuronal
cells, however, studies have identied functional nAChRs
in tissues outside the nervous system. Actions on nicotinic
receptors produce a wide variety of acute and long-term
effects on organ systems, cell multiplication and apoptosis,
throughout the body.
IMMEDIATE EFFECTS AND TOXICITY
Nicotine on direct application in humans causes irritation
and burning sensation in the mouth and throat, increased
salivation, nausea, abdominal pain, vomiting and diarrhea.[17]
Gastrointestinal effects are less severe but can occur even
after cutaneous and respiratory exposure.[18] Predominant
immediate effects as seen in animal studies and in humans
consist of increase in pulse rate and blood pressure.
Nicotine also causes an increase in plasma free fatty
acids, hyperglycemia, and an increase in the level of
catecholamines in the blood.[19,20] There is reduced coronary
blood ow but an increased skeletal muscle blood ow.[20,22]
The increased rate of respiration causes hypothermia, a
Table 1: Studies showing nicotine
as a carcinogen
Author Model System References
Jensen et al., 2012 Animal Gastrointestinal [50]
Schuller et al., 1995 Animal Lung cancer [45]
Nakada et al. 2012 Human Tumor promoter
in lung cancer
[46]
Al-Wadei et al., 2009 Mice Pancreatic cancer [56]
Treviño et al., 2012 Animal Pancreatic cancer [58]
Crowley-Weber et al.,
2003
Human Pancreatc cancer [57]
Chen et al., 2011 Human Breast cancer [59]
Wassenaar et al., 2013 Human Lung [44]
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Mishra, et al.: Harmful effects of nicotine
26 Indian Journal of Medical and Paediatric Oncology | Jan-Mar 2015 | Vol 36 | Issue 1
hypercoagulable state, decreases skin temperature, and
increases the blood viscosity.
Nicotine is one of the most toxic of all poisons and has a
rapid onset of action. Apart from local actions, the target
organs are the peripheral and central nervous systems. In
severe poisoning, there are tremors, prostration, cyanosis,
dypnoea, convulsion, progression to collapse and coma.
Even death may occur from paralysis of respiratory muscles
and/or central respiratory failure with a LD50 in adults
of around 30-60 mg of nicotine. In children the LD50 is
around 10 mg.[23]
GREEN TOBACCO SICKNESS
This is an acute form of nicotine toxicity that is known
to occur due to handling of green tobacco leaves, with
symptoms lasting from 12 to 24 h. The acute symptoms
include headache, nausea, vomiting, giddiness, loss of
appetite, fatigue and tachyarrythmias.[24] No signicant
mortality has been reported due to green tobacco sickness
(GTS) but it signicantly affects the health of workers in
the tobacco industry.[25]
NICOTINE ADDICTION
Nicotine is one of the most addicting agent. The US
surgeon general (2010) has concluded nicotine to be as
addictive as cocaine or heroin. Nicotine interacts with
the nicotinic acetyl choline receptors and stimulates the
dopaminergic transmission.[26] This in turn stimulates the
reward centre and is responsible for the mood elevation
and apparent improvement in cognitive function.[27] With
chronic stimulation by nicotine the GABAergic neurons
are desensitized and thus lose their inhibitory effect on
dopamine.[28] This in turn reinforces the addiction by
inducing craving. This effect has been shown to affect
the CYP2A6 gene and leads to heritable dependence to
nicotine. Studies have shown the nicotine dependence to be
transmitted maternally and grand maternally by epigenetic
mechanism.[29]
EFFECTS ON METABOLISM
Nicotine causes catecholamine release and stimulates the
autonomic system. There is increased glycogen synthesis
due to α-adrenoceptor stimulation. This leads to reduction
in the fasting blood glucose levels. It also causes lipolysis
thus decreasing body weight. Nicotine affects insulin
resistance and predisposes to metabolic syndrome. In an
animal study prenatal exposure was toxic to pancreatic
β-cell and leads to decreased B cell population, thus
increasing the risk of diabetes.[30,31]
NICOTINE AND CANCER
The stimulation of nAChRs by nicotine has biologic
effects on cells important for initiation and progression of
cancer.[26] It activates signal transduction pathways directly
through receptor-mediated events, allowing the survival of
damaged epithelial cells. In addition, nicotine is a precursor
of tobacco specific nitrosamines (TSNAs), through
nitrosation in the oral cavity.[32,33] It is shown that nitrosation
of nicotine could lead to formation of NNN and NNK.
This effect of nicotine may be important because of its
high concentration in tobacco and nicotine replacement
products.[13] NNN and NNK are strongly carcinogenic.[34]
Nicotine forms arachidonic acid metabolites which cause
increased cell division. Binding to Bcl-2 and action on
vascular endothelial growth factor and cyclooxygenase-2
(COX-2) causes increased cancer proliferation and
survival.[35,36] Promotion of tumor angiogenesis accelerates
tumor growth which is mediated by β-adrenergic activation
and stimulation of nAChRs.[35,37-39] Nicotine also suppresses
apoptosis by phosphorylation mediated extracellular
signal regulated kinases of Bcl-2.[40,41] Recent studies show
that nicotine, activates nuclear factor kappa B (NF-kB)-
dependent survival of cancer cell and proliferation.[42]
In normal cells, nicotine can stimulate properties consistent
with cell transformation and the early stages of cancer
formation, such as increased cell proliferation, decreased
cellular dependence on the extracellular matrix for survival,
and decreased contact inhibition. Thus, the induced
activation of nAChRs in lung and other tissues by nicotine
can promote carcinogenesis by causing DNA mutations[26]
Through its tumor promoter effects, it acts synergistically
with other carcinogens from automobile exhausts or wood
burning and potentially shorten the induction period of
cancers[43] [Table 2].
LUNG CARCINOGENESIS
A study relates lung carcinogenesis by nicotine due to
genetic variation in CYP2B6.[44] Its simultaneous exposure
with hyperoxia has been found to induce cancer in
hamsters.[45] Cotinine has been found to promote lung
tumorigenesis by inhibiting anti-apoptotic pathway.[46]
Nuclear translocation of ARB1 gene by nicotine has
found in proliferation and progression of nonsmall-cell
lung cancer. Several Studies have shown that nicotine
has signicant role in tumor progression and metastasis
via CXCR4 and increased angiogenesis.[36,47] Carriers of
the lung-cancer-susceptibility loci in their DNA extract
more nicotine. Smokers carrying the gene CHRNA3 and
CHRNA5 were found to extract more nicotine and cells
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Indian Journal of Medical and Paediatric Oncology | Jan-Mar 2015 | Vol 36 | Issue 1 27
were thus exposed to a higher internal dose of carcinogenic
nicotine-derived nitrosamines.[48] Additionally modulation
of the mitochondrial signaling pathway leads to resistance
to the chemotherapeutic agents.[49]
GASTRO INTESTINAL CARCINOGENESIS
The carcinogenic role may be mediated by the MAPK/
COX-2 pathways, α-7 nAchR and β-adrenergic receptor
expression, and mi RNAs α-BTX anatagonist.[50]
Nicotine forms adducts with liver DNA which enhances
its mutagenic potential.[49,51,52] activation of cell-surface
receptors by nicotine stimulates downstream kinases that
can mediate resistance to chemotherapy. It has been shown
by the nding that smokers who continue to smoke during
chemotherapy have a worse prognosis. Moreover they
also have increased toxicity and lower efcacy of chemo
therapeutic drugs.[53] Nicotine affects the periostin gene,
α-7-nAChR and e-cadherin suppression which explains
the mechanism of gastric cancer growth, invasion and
metastasis.[54,55] Nicotine negatively impacts tumor biology
by promoting angiogenesis, tumor invasion and increased
risk of metastasis.[53]
PANCREATIC CANCER
Nicotine has been found to induce pancreatic
adenocarcinoma in mice model, by stimulating the stress
neurotransmitters.[56,57] In another study nicotine promoted
the growth of nonsmall cell lung cancer and pancreatic
cancer in a receptor dependent fashion. It also increased
tumor metastasis, and resistance to gemcitabine induced
apoptosis, causing chemoresistance.[58] The MUC-4
upregulation, NF-kB and GRP78 activation and Id1
expression by Src dependent manner are the probable
mechanism leading to tumor growth, metastasis and
chemotherapeutic drug resistance.[57,58]
BREAST CANCER
Nicotine causes α9-nAChR-mediated cyclin D3
overexpression which might cause transformation of
normal breast epithelial cells and induce cancer. Nicotine
and cotinine has been found to be present in the breast
uid of lactating women.[59] Several studies have found
that α9-nAChR mediated mechanism leads to increased
tumor growth, metastasis and tumor cells resistant to
chemotherapeutic drugs in breast cancer.[59,60]
CARDIOVASCULAR SYSTEM
The acute hemodynamic effects of cigarette smoking
or smokeless tobacco are mediated primarily by
the sympathomimetic action. The intensity of its
hemodynamic effect is greater with rapid nicotine
delivery.[61] Nicotine causes catecholamine release both
locally and systemically leading to an increase in heart
rate, blood pressure and cardiac contractility. It reduces
blood ow in cutaneous and coronary vessels; and
increases blood ow in the skeletal muscles. Due to
restricted myocardial oxygen delivery there is reduced
cardiac work. In a study, chewing a low dose (4 mg)
of nicotine gum by healthy nonsmokers blunted the
increase in coronary blood flow that occurs with
increased heart rate produced by cardiac pacing.[21]
Thus, persistent stimulation by nicotine can contribute
to Coronary Vascular Disease by producing acute
myocardial ischemia. In the presence of coronary
disease, myocardial dysfunction can be worsened. In a
placebo-controlled experiment that produced transient
ischemia in anesthetized dogs myocardial dysfunction
was produced at doses, that did not alter heart rate,
blood pressure, or blood ow or myocyte necrosis.[62]
Nicotine alters the structural and functional characteristics of
vascular smooth muscle and endothelial cells.[63] It enhances
release of the basic broblast growth factor and inhibits
production of transforming growth factor-β1.[64] These
effects lead to increased DNA synthesis, mitogenic activity,
endothelial proliferation and increases atherosclerotic
plaque formation.[65] Neovascularization stimulated
by nicotine can help progression of atherosclerotic
plaques.[66] These effects lead to myointimal thickening and
atherogenic and ischemic changes, increasing the incidence
of hypertension and cardiovascular disorders. A study on
Table 2: Studies showing the role of nicotine
as tumor promoter
Author System References
Chu et al., 2013 Gastrointestinal
tumor growth
[71]
Improgo et al., 2013 Lung [47]
Heusch and Maneckjee, 1998 Lung [40]
Mai et al., 2003 Lung [41]
Shin et al., 2005 Gastric [36]
Heeschen et al., 2001 Tumor growth and
angiogenesis
[35]
Zhu et al., 2003 Tumor angiogenesis
and growth
[39]
Heusch and Maneckjee, 1998 Lung [40]
Le Marchand et al., 2008 Lung [48]
Perez-Sayans et al., 2010 GIT [51]
Zhang et al., 2010 GIT [49]
Petros et al., 2012 Chemoresistance [53]
Trevino et al., 2012 Tumor growth and
chemoresistance
[90]
GIT – Gastrointestinal tract
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28 Indian Journal of Medical and Paediatric Oncology | Jan-Mar 2015 | Vol 36 | Issue 1
dogs demonstrated the deleterious effects of nicotine on
the heart.[67]
Nicotinic acetylcholine receptor’s actions on vascular
smooth muscle proliferation and plaque neovascularization
increases the risk of peripheral arterial disorders. In a
murine model of hind limb ischemia, short-term exposure
to nicotine paradoxically increased capillary density and
improved regional blood ow in the ischemic hind limb.
[35] However, long-term exposure to nicotine for 16 weeks
(about one-third of the life span of a mouse) before
induction of ischemia obliterated angiogenic response to
nicotine.[68]
RESPIRATORY SYSTEM
The effects of nicotine on respiratory system are twofold.
One, directly by a local exposure of lungs to nicotine
through smoking or inhaled nicotine, and second via
a central nervous system mechanism. Nicotine plays a
role in the development of emphysema in smokers, by
decreasing elastin in the lung parenchyma and increasing
the alveolar volume. Nicotine stimulates vagal reex
and parasympathetic ganglia and causes an increased
airway resistance by causing bronchoconstriction.[69]
Nicotine alters respiration through its effects on the
CNS. The simultaneous effect of bronchoconstriction
and apnea increases the tracheal tension and causes
several respiratory disorders. In a study microinjection
of nicotine were administered to the prebotzinger
complex and adjacent nuclei in the brain. The ring
pattern of the brain signals and breathing pattern were
monitored. There was an increased frequency of bursts
and decreased amplitude and a shallow and rapid rhythm
of respiration.[70]
GASTROINTESTINAL SYSTEM
Nicotine use has been associated with Gastro Esophageal
Reux Disorder (GERD) and peptic ulcer disease (PUD).
[36,71] This effect is mediated by increased gastric acid,
pepsinogen secretion and stimulatory effects on vasopressin.
The action on the cyclo-oxygenase pathway also increases
the risk of GERD and PUD.[72] Nicotine causes smooth
muscle relaxation by action of endogenous nitric oxide
as a nonadrenergic noncholinergic neurotransmitter.[73]
The decrease in tone of the colon and gastric motility and
reduced lower esophageal sphincteric pressure might be
the reason of increased incidence of GERD.[74]
There is an increased incidence of treatment resistant
Helicobacter pylori infection in smokers. It potentiates the
effects of toxins of H. pylori by its action on the gastric
parietal cells.[75] This effect could be due to histamine
mediated response of nicotine.
IMMUNOLOGICAL SYSTEM
Nicotine has been known to be immunosuppressive through
central and peripheral mechanisms. It impairs antigen and
receptor mediated signal transduction in the lymphoid
system leading to decreased immunological response. The
T-cell population is reduced due to arrest of cell cycle.
Even the macrophage response, which forms the rst
line defense against tuberculosis becomes dysfunctional
and causes increased incidence of tuberculosis.[76] The
migration of broblasts and inammatory cells to the
inamed site is reduced. There is decreased epithelialization
and cell adhesion and thus there is a delayed wound healing
as well as increased risk of infection in nicotine exposed
individuals.
The action on the hypothalamo-pituitary adrenal axis and
autonomic nervous system stimulation via sympathetic and
parasympathetic pathways affects the immune system. The
adrenocorticotropic hormone (ACTH) secretion pathway
and corticotrophin release is affected and this causes
immunosuppression.[77]
OCULAR SYSTEM
Nicotine promotes pathologic angiogenesis and retinal
neovascularization in murine models. It causes age-related
macular degeneration in mice.[78] In a clinical study, the
most virulent form of age-related maculopathy was
associated with retinal neovascularization that contributed
to visual deterioration. Tobacco smokers are known to be
at greater risk of age-related macular degeneration than
are nonsmokers.[79] In animal model, spraguely Dawley
rats with type 1 diabetes treated with nicotine, developed
cataract.[80] Thus the syngergistic relationship between
nicotine and glucose metabolism exaggerating diabetes
might cause accelerated cataract formation. There is
synergistic relationship between nicotine and glucose
metabolism which increases the risk of diabetes mellitus.
This might cause accelerated cataract formation.
RENAL SYSTEM
Risk of chronic kidney disease in smokers is high. Cigarette
smoking has been found to increase albumin excretion in
urine, decrease glomerular ltration rate, causes increased
incidence of renal artery stenosis and is associated with an
increased mortality in patients with end-stage renal disease.
The pathogenesis of renal effects is due to the action
of nicotine via COX-2 isoform induction. The COX-2
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Indian Journal of Medical and Paediatric Oncology | Jan-Mar 2015 | Vol 36 | Issue 1 29
isoforms causes increased glomerular inammation, acute
glomerulonephritis and ureteral obstruction.[81] There is
impaired response of kidneys to the increased systemic
blood pressure in smokers. This loss of renoprotective
mechanism in smokers also leads to pathogenetic effects
of nicotine on the renal system.[82]
REPRODUCTIVE SYSTEM — MALES
Nitrous oxide liberated from parasympathetico-nergic
nerves plays a pivotal role in generating immediate penile
vasodilatation and corpus cavernosum relaxation, and NO
derived from endothelial cells contributes to maintaining
penile erection. Nicotine causes impairment of NO
synthesis. This may lead to loss of penile erections and
erectile dysfunction.[83]
Various animal studies suggest that nicotine causes
seminiferous tubules degeneration, disrupts the
spermatogenesis and at cellular level, affect germ cell
structure and function in males.[84] It decreases testosterone
levels which is secondary to decreased production of
StAR.[85] StAR is the protein which plays an important role
in testosterone biosynthesis.
REPRODUCTIVE SYSTEM — FEMALE
Menstrual cycle
Nicotine by inhibiting the 21 hydoxylase causes
hypoestrogenic state. It shunts the metabolites to
formation of androgen. This leads to chronic anovulation
and irregular menstrual cycles. Nicotine can predispose
the endometrium to inappropriate cytokine production
and irregular bleeding.[86] There is consistent evidence
that increase in follicle-stimulating hormone levels
and decreases in estrogen and progesterone that are
associated with cigarette smoking in women, is atleast in
part due to effects of nicotine on the endocrine system.[26]
Effect on oocytes
Nicotine affects the ovaries and alters the production of
oocytes in various animal studies. Nicotine-treated oocytes
appeared nonspherical with rough surface and torn and
irregular zona-pellucida. Nicotine also caused disturbed
oocyte maturation. There is a decreased blood ow to the
oviducts and thus impaired fertilization.[87]
Peri-natal effects
Maternal smoking has always been known to have
deleterious effects on the fetal outcome. There is an
increased incidence of intrauterine growth restriction,
still birth, miscarriages and mental retardation.[88] Various
animal studies show retarded fetal growth and lower birth
weight when treated perinatally with nicotine. The lower
levels of ACTH and cortisol due to nicotine are probable
reasons for the incidence of lower birth weight in the
newborns.[89]
Maternal as well as grand maternal smoking has been found
to increase risk of pediatric asthma. Another serious and
important effect is the transgenic transmission of the
addictive pattern.[29]
CONCLUSION
Nicotine is the fundamental cause of addiction among
tobacco users. Nicotine adversely affects many organs as
shown in human and animal studies. Its biological effects
are widespread and extend to all systems of the body
including cardiovascular, respiratory, renal and reproductive
systems. Nicotine has also been found to be carcinogenic
in several studies. It promotes tumorigenesis by affecting
cell proliferation, angiogenesis and apoptotic pathways. It
causes resistance to the chemotherapeutic agents. Nicotine
replacement therapy (NRT) is an effective adjunct in
management of withdrawal symptoms and improves the
success of cessation programs. Any substantive benecial
effect of nicotine on human body is yet to be proven.
Nicotine should be used only under supervision of trained
cessation personnel therefore its sale needs to be strictly
regulated. Needless to say, that research for safer alternative
to nicotine must be taken on priority.
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How to cite this article: Mishra A, Chaturvedi P, Datta S,
Sinukumar S, Joshi P, Garg A. Harmful effects of nicotine. Indian J
Med Paediatr Oncol 2015;36:24-31.
Source of Support: Nil. Conict of Interest: None declared.
[Downloaded free from http://www.ijmpo.org on Wednesday, September 16, 2015, IP: 14.139.127.162]
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... Regardless of the situation, nicotine is a molecule capable of promoting addiction (ANVISA, 1072;Olson, 2014). Most studies related toxic effects from tobacco considering smoking or cigarette exposition (Balbani & Montovani, 2005;Mishra et al., 2015;Moreno-Coutiño & Bello, 2012;Olson, 2014;Trilha, 2009), and there are no studies on tobacco exposition from shamanic snuff. ...
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... Nicotine was also detected as an alkaloid compound in bottled drinking water samples in Spain with an average concentration of 0.012 μg/L (Alonso et al. 2012). Nicotine is well-known as a highly addictive chemical that can cause adverse effects on the heart, reproductive system, lung, kidney, and multiple organs (Mishra et al. 2015). Nonylphenol (NP), octylphenols (OPs), triclosan (TCS), Aps, and BPA are endocrine-disrupting chemicals (EDCs) that have raised significant environmental and health concerns due to their estrogenic activity (Priac et al. 2017). ...
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