Common Name:
Lobelia
Botanical Name:
Lobelia inflata L. Other species include L. cardinalis L., L. siphilitica L.,
and L. spicata L.
Family:
Campanulaceae
Other Names:
English:
German:
French:
Trade Name:
Parts Used:
The dried aerial parts are generally used, but some herbalists prefer the
fresh tinctured plant. The roots were used by indigenous people as a
diuretic.
Indian tobacco, Pukeweed
Lobelienkraut, Spalglockchen, Indianischer Tabak
Lobelie enflee
Herba Lobeliae inflatae1
Constituents:
Alkaloids (0.2-0.6% total, BP min. 0.25% total calculated as lobeline)2:
At least 14 different piperidine alkaloids, principally (-)-lobeline, with
lesser amounts of meso-lobelanine, meso-lobelanidine; and the
piperideines. These alkaloids are biosynthetically formed from two
molecules of phenylalanine and one molecule of lysine.3
Carboxylic acids: chelidonic acid and beta-beta-phenyloxyproprionic acid.
Actions:
Parasympathomimetic
Respiratory stimulant
Emetic
Expectorant
Anti-spasmodic
Sialagogue
Diuretic
Anthelmintic
Historical Note:
Lobelia grows throughout much of the United States but much of the
written literature on this plant is from the colonial period of the east coast.
While the Penobscots and other Eastern indigenous peoples used L. inflata
as an expectorant and emetic to clear the stomach before “their great
councils,” other species of Lobelia were used far more often. L. siphilitica
was so named because the Iriquois peoples believed the root to be a cure
for syphilis. While the efficacy of this root to cure syphilis remained in
great debate in the early 1800’s, a number of practitioners found it
effective for the treatment of gonorrhea, and it was a popular diuretic. L.
Copyright Tieraona Low Dog, MD 2008.
cardinalis was used by many tribes as an anthelmintic, its actions similar
to L. inflata but weaker. L. inflata was used for the treatment of asthma,
bronchitis, pneumonia, angina, as an emetic, and colic. The leaves were
often smoked for the relief of asthma. Samuel Thompson encouraged the
use of lobelia for the treatment of asthma and bronchitis and as an antispasmodic and anti-convulsive. Popularity grew in spite of reported
poisonings. The dried leaves and tops were official in the USP for their
emetic and expectorant properties (1820-1936) and in the NF (19361960).4
Pharmacology:
Structurally and pharmacologically, lobeline is similar to nicotine but less
potent. Lobeline has both stimulant and depressant phases of action.
Because lobeline effects so many systems in the body, it is probably
simpler to break it down by body system.
Cardiovascular System: at low doses, the release of epinephrine and
norepinephrine by the adrenal medulla, stimulates the heart rate and mildly
elevates blood pressure. This results from activation of both the aortic and
carotid chemoreceptors, leading to tachycardia and vasoconstriction with a
subsequent rise in systolic and diastolic blood pressure.
Gastrointestinal Tract: in general, via stimulation of the parasympathetic
nervous system, gastric acid production is increased, while bowel tone and
peristalsis is enhanced. Occasionally, diarrhea is encountered from the
ingestion of excessive amounts of lobelia. The vomiting that occurs from
the ingestion of lobelia is the result of both central and peripheral actions.
The alkaloids stimulate the area postrema of the medulla oblongata, better
known as the “vomiting center.” Lobeline also stimulates both vagal and
spinal nerves, which are part of the reflex pathway of vomiting. The name
“pukeweed” is quite an appropriate term.
Peripheral Nervous System: lobeline transiently stimulates and then
depresses almost all autonomic ganglia. Small doses of lobelia directly
stimulate the ganglia and enhance nerve transmission. Larger doses
stimulate the ganglion cell, quickly followed by a blockade of nerve
transmission. Small doses of lobelia stimulate the adrenal medulla to
release epinephrine (adrenalin), while larger doses inhibit the release of
epinephrine due to stimulation of the splanchnic nerves. Lobeline
stimulates a number of sensory receptors; the stretch and pressure sensitive
mechanoreceptors of the tongue, skin, lung, and stomach; the
chemoreceptors of the carotid body; pain receptors and the thermal
receptors of both the skin and tongue.
Central Nervous System: small doses stimulate the CNS. Larger doses,
can cause tremors and convulsions. In very large doses, if emesis does not
clear the alkaloid, depression of the CNS occurs and death can result from
respiratory failure secondary to both central depression and peripheral
blockade of respiratory musculature.5
Respiratory System: lobeline initially causes a mild increase in salivation
and bronchial secretions, then has an inhibitory action. Small doses of
lobelia cause excitation of the respiratory tract reflexly through stimulation
of the chemoreceptors in the carotid and aortic bodies. Large doses cause
respiratory depression as mentioned in the previous paragraph.
Stimulation of adrenal catecholamines causes -adrenergic bronchodilator.
Applications:
Respiratory: Lobelia is still used by herbalists in the treatment of asthma
and chronic bronchitis. Those with copious mucus production but
difficulty removing it (i.e., emphysema, chronic bronchitis), find that
lobelia reduces secretions while helping expectoration. Lobelia is of
benefit in cases of pneumonia when there is a subjective feeling of
“weight” on the chest and an inability to take a deep breath.6 Spasmodic
asthma responds quite well to the plant when taken properly. Small doses
initially cause expectoration, which is then followed by relaxation of the
bronchioles and easing of the cough. The herb may be used in small daily
doses to keep the lungs free from excessive accumulation of secretions in
those with emphysema. In cystic fibrosis, there is a marked increase in the
production of pulmonary secretions, the sputum often being quite viscous
and purulent. Lobelia is an excellent choice for this population because of
its ability to assist in expectoration. Chronic bronchitis, defined as
excessive tracheo-bronchial mucus production sufficient to cause cough
with expectoration, is quite prevalent in the United States. This is largely
the result of tobacco smoking, increased air pollution and occupations that
expose their workers to organic/inorganic dusts, or noxious gases.
Inflammation of the small airways and hyperplasia of the mucus-producing
glands in the large airways are characteristic of the disease. Lobelia, along
with licorice and ginkgo, is beneficial in keeping the lungs free from
excessive mucus helping to reduce infection.
Gastrointestinal. Lobelia effectively increases secretions and motility of
the stomach and bowel. Significant amounts of gastric mucus are
produced which may be a result of gastric irritation. Taking lobelia with
an herb such as chamomile or licorice is probably wise to protect the gut.
Appetite is stimulated, flatulence reduced, and digestion enhanced with
small doses of lobelia. The aerial parts of the plant enhance exocrine
secretion from the pancreas, thus aiding in the digestion of starches,
proteins, and fats. Lobelia combines quite nicely with the anthraquinone
Copyright Tieraona Low Dog, MD 2008.
containing laxatives to overcome habitual constipation. Peristalsis is
enhanced, while griping can occur with stronger cathartics. Lobelia may
be considered in cases of spastic colon.
Reproductive. Lobelia is sometimes employed by midwives during early
labor to relax a thick and rigid os. With oral ingestion, lobelia relaxes the
perineal muscles, easing a difficult labor.
Nervous & Muscular Systems Lobelia is a useful anti-spasmodic. The
British Herbal Compendium recognizes lobelia for the treatment of spastic
muscle conditions. Lobelia may be considered when there is spasticity or
muscular rigidity, i.e.; the spasticity that can accompany multiple sclerosis;
myoclonus, and some of the dystonias. When lobelia is combined with
capsicum, the resulting liniment is very effective when applied topically
for neuralgia, easing the pain from bruising, sprains and strains; easing
muscle spasm, and reducing muscle fasciculation. The herb is
occasionally combined with valerian and cramp bark for the relief of
tension headaches.
Urinary system. Lobelia may be useful in some cases of hyper-reflexic
bladder; complaints such as incontinence, urgency and frequency are
common. Lobelia has a mild contractile effect on the urinary bladder. The
roots of all species of lobelia have substantial diuretic properties.
Pharmacokinetics:
Lobelia is well absorbed from mucous membranes of the mouth,
gastrointestinal and respiratory systems. Lobeline is metabolized primarily
by the liver, kidney, and lung, with rapid excretion by the kidneys.7 The
rate of excretion is enhanced with acidic urine and diminished by alkaline
urine. Thus, vegetarians may be slower to eliminate the alkaloids present
in the plant and more at risk to adverse effects.
Drug Interactions:
Caution should be exercised when using lobelia with other strong muscle
relaxants or central nervous system depressants. Lobelia binds nicotinic
receptors and should be used with caution in patients receiving nicotine
therapies for tobacco withdrawal.
Toxicology:
Overdose of Lobelia can cause severe adverse effects including vomiting,
profuse sweating, muscular paralysis, tachycardia, hypotension, respiratory
failure secondary to respiratory muscle paralysis, coma and death.
Fatalities have been recorded from overdose of this plant. On EKG, one
will see extrasystole, sinus arrhythmia and bundle branch block. For
overdose: treatment consists of emesis (which usually occurs naturally
with overdose); activated charcoal and purgatives should be given. In
severe overdose, atropine 2 mg. subcutaneously, warming blankets, and
dopamine is indicated if the individual is hypotensive. A ventilator may
be necessary if respiratory paralysis occurs.
Side Effects:
Nausea is the most common side effect reported by individuals. Other
side effects include coughing, dizziness, increased blood pressure,
heartburn, and diaphoresis.
Contra-Indications: Lobelia should not be used by nursing mothers as the alkaloids are
excreted in breast milk. Lobelia should not be used by those with rapid
evacuation of bowels, hypersecretion of stomach acid, tendency towards
ulcers, etc. Should not be used by those with impaired mental cognition
who may be at a higher risk of aspiration and unable to communicate when
they are feeling nauseated. Lobelia should be used cautiously in those
with hepatic or renal impairment.
Dose:
A significant problem in using lobelia is the lack of standardized
preparations for internal use. Considering the potential toxicity of the
alkaloids, this can make lobelia a potentially dangerous plant for use by an
uneducated public. The following tincture dosage is from the BPC of
1973.
Tincture of dried aerial parts - 1:5 with 60% alcohol
Adults: 0.3 ml - 1 ml. TID8
Children: calculated for age and weight.
Always start at the low end of dosage range and titrate upwards as needed.
Dried herb: 50-200 mg. in infusion TID.
Author’s Notes:
While there is undoubtedly risk from toxic doses of the plant, in the hands
of a skilled practitioner, lobelia makes a useful addition to herbal
combinations for spastic colon, chronic bronchitis, and muscle spasticity.
However, because of its potential toxicity, this is not an herb I recommend
for general use by the public.
Copyright Tieraona Low Dog, MD 2008.
1
Steinmetz, E.F. Codex Vegetabilis Entry number 670. Self-published, 1957.
British Herbal Compendium Volume 1. Bradley, P. Ed. British Herbal Medicine Association, Dorset, 1992.
3
Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. Lavoisier Publishing, Paris, 1995. Pages 695-96.
4
Vogel V. American Indian Medicine. Oklahoma Press, Norman, Oklahoma, 1970. Pages 330-32.
5
Damaj MI, et al. Pharmacology of lobeline, a nicotine receptor ligand. J Pharm Exp Ther 1997; 282:410-19.
6
Felter HW, Lloyd JU. King’s American Dispensary. Eclectic Medical Publications, Portland, Oregon, 1983.
Pages 1199-1205. Original publication 1898.
7
Westfall TC, Meldrum MJ. “Ganglionic Blocking Agents” in Craig CR, Stizel RE. Modern Pharmacology 2nd Ed.
Little, Brown and Company, Boston, 1986.
8
British Herbal Compendium Vol. 1. Bradley, Peter Ed. British Herbal Medicine Association, Dorset, 1992. Pages
149-50.
2