Campanulaceae (Plant Family)
Lobelia inflata is indigenous to the flora of Canada, Kamchatka, and
the northeastern United States. It has a long history of medicinal use as a
respiratory stimulant, antiasthmatic, antispasmodic, expectorant, and emetic
therapy. Well-known to Native Americans, this acrid-tasting plant is also called
Indian tobacco. It was also highly touted by the Thomsonians, a group of
nineteenth-century health care practitioners sarcastically labeled
"lobelia doctors." Herbalists have traditionally combined lobelia with other
medicinal plants such as cayenne pepper, lungwort, Ma Huang, or licorice.
American Indians historically smoked lobelia as a treatment for asthma. More
recently, individuals have smoked dried lobelia herb as a recreational
At one time, lobelia was approved by the FDA for use as a major ingredient in
antismoking, herbal preparations. Lobelia reportedly alleviated symptoms of
nicotine withdrawal during smoking cessation. However, the rationale for doing
this was eventually called into question since lobelia possesses many of the
same pharmacological properties of nicotine. The crude drug is now considered
unsafe both as an antismoking agent and as a treatment for asthma and
bronchitis. Many authorities in plant drug research claim that the risk of
potential toxicity from the alkaloids present in lobelia outweigh its benefits.
Pharmacological support for the effectiveness of lobelia as a therapeutic
agent (other than as a sedative) and euphoriant is weak. Although lobelia has a
favorable stimulatory action on the respiratory center, it is metabolized too
quickly to be considered an efficacious respiratory analeptic (restorative).
Lobelia is a visually attractive, annual or sometimes biennial herb that
grows to a height of 50 cm. It erect, hairy stem is angular, branching at the
top, and characteristically green with a tinge of violet. The pale green or
yellowish leaves are narrow, lance-shaped, and short-stemmed. They are alternate
or oblong, with hairy veins and irregularly toothed margins. The leaves have an
acrid taste and a slightly irritating odor. The sparse, small, two-lipped
flowers are pale violet-blue outside and pale yellow inside. The flowers grow in
a terminal spike on long pedicles in the leaf axils.
Herb (aerial parts), leaves, tops, seeds.
Piperidine-type alkaloids (0.48%): lobeline, lobelanine, lobelanidine,
norlobelanine, lelobanidine, norlelobanidine, norlobelanidine, lobinine; bitter
glycoside (lobelacrin), chelidonic acid, fats, gum, resin, volatile oil.
Available for oral intake as dried herb and liquid preparations, including
tinctures; and for topical use in ointments, lotions, suppositories, and
Traditional uses: Taken internally for angina pain, bronchitic asthma,
chronic bronchitis, particularly spasmodic asthma with secondary bronchitis, and
symptoms of smoking withdrawal; applied externally for myositis and rheumatic
Conditions: Asthma, spasmodic asthma with secondary bronchitis, chronic
bronchitis, spastic colon, spastic muscle conditions, pneumonia.
Clinical applications: Respiratory stimulant, spasmolytic,
The pharmacological effects of lobelia are attributed primarily to
piperidine-type alkaloid constituents, particularly lobeline. Although lobeline
is less potent than nicotine, its actions on the peripheral and central nervous
(CNS) systems are similar to those of nicotine. According to other research,
however, the principle pharmacological activity of lobeline is not nicotinic
agonism. Rather, lobeline may affect CNS activity by altering the dopamine
chemistry of the brain. Lobeline has been shown to be more potent than
d-amphetamine in blocking dopamine uptake into synaptic vesicles.
In normal doses, lobeline functions as a CNS stimulant that dilates the
bronchioles, thereby increasing respiration. However, the initial bronchial
dilation is often followed by an adverse effect of respiratory depression,
particularly during overdosing.
Lobeline induces reflex stimulation of the respiratory center by acting on
the chemoreceptors of the glomus caroticus. This medicinal plant presumably
exerts its antiasthma activity by stimulating the adrenal glands to release
epinephrine, which in turn binds to beta-2 receptors. The net effect of this
physiological property is relaxation of the airways. Lobelia also affects
gastrointestinal function by stimulating the vomiting center in the reticular
formation of the medulla oblongata at the base of the brain.
In an in vivo experiment, a crude methanolic leaf extract of
Lobelia inflata produced antidepressant effects in mice. The active
constituent responsible for this activity was identified as beta-amyrin
palmitate. In another study, the in vivo actions of beta-amyrin palmitate
on central nervous system activity were compared with those of two
antidepressant drugs, mianserin and imipramine. Beta-amyrin palmitate
(administered at 5, 10 and 20 mg kg/1) produced a dose-related decrease in
locomotor activity of mice and had an antagonistic effect on
methamphetamine-induced locomotor stimulation.
In addition, beta-amyrin palmitate at these same doses exhibited potentiating
action on chemically-induced narcosis in test animals. Beta-amyrin palmitate was
milder than mianserin but more potent than imipramine in eliciting the
potentiating effect. These findings offer pharmacological evidence for the
sedative properties of lobelia. However, since oral preparations of lobeline are
metabolized so rapidly that their effects are only transitory, topical
applications may be more efficacious.
|Dosage Ranges and Duration of
- Dried herb (infusion or decoction): ¼ to ½ tsp. herb in 8 oz. water,
preferably mixed with other herbs; steep 30 to 40 minutes. Take 2 oz. qid. (This
method is not preferred because of lobelia's acrid taste.)
- Liquid extract (1:1 in 50% alcohol): 0.2 to 0.6 ml tid
- Tincture of lobelia: 0.6 to 2.0 ml
- Vinegar tincture of lobelia (1:5 in dilute acetic acid): 1 to 4 ml
Some practitioners recommend starting dosage at 7 to 8 drops, adding a drop
with every dose. If the patient experiences nausea, cut back the dosage.
Note: Therapy should begin with the use of lower level dosages and increased
appropriately depending upon individual patient response.
Both lobelia and its main active principle, lobeline, can produce undesirable
symptoms of nausea, vomiting, diarrhea, coughing, dizziness, disturbed hearing
and vision, mental confusion, and weakness. All these symptoms resemble toxic
reactions to nicotine.
Overdosage of lobelia may cause adverse side effects of shivering, profuse
sweating, tachycardia, convulsion, hypothermia, hypotension, coma, and, in
extreme cases, death due to respiratory failure. Ingestion of 0.6 to 1 g of
lobelia leaves is reportedly toxic.
Note: In cases of acute toxicity from lobelia, atropine (2 mg) should be
administered subcutaneously as an antidote.
Lobelia should not be consumed in excessive amounts because of the toxicity
of its potent alkaloid compounds. As in the case of nicotine, lobelia and
lobeline are contraindicated during pregnancy and lactation.
No clinically significant interactions between lobelia and conventional
medications are known to have been reported in the literature to
|Regulatory and Compendial
Lobelia has not been designated as an approved herb, or an unapproved herb,
by the German Commission E. In the United Kingdom, lobelia (in doses of up to 65
mg per single dose) is on the General Sale List, Schedule 1, Table A. Higher
oral doses of up to 200 mg per dose (600 mg per day) and external preparations
containing quantities of not more than 10% lobelia are reserved for pharmacy use
only in the United Kingdom. Herbal practitioners are exempt from this
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Copyright © 2000 Integrative Medicine
CommunicationsThis publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
responsibility for the accuracy of the information or the consequences arising
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are made for any drugs or compounds currently marketed or in investigative use.
The reader is advised to check product information (including package inserts)
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interactions, and contraindications before administering any drug, herb, or
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