Cutler described its utility in asthma in 1813 and Reece introduced this drug in 1829 to English medical profession.
The herb found indigenous to Eastern and Central U.S.A, and Holland consists of dried aerial parts of Lobelia inflata Linn. (Lobelia BP/USP) of the family Campanulaceae. It is official in British Pharmacopoeia and United States Pharmacopoeia. The Indian herb of lobelia consists of dried aerial parts of Lobelia nicotianae folia Heyne (Lobelia IP) of the family Campanulaceae. Lobelia is also referred as Indian tobacco, Herba lobelia, Lobelia herb or Asthma weed. Lobelia should contain not less than 0.55 percent of total alkaloids, calculated as lobeline.
Lobelia consists of stems, leaves, flowers, fruits and seeds.
Morphological features of Lobelia BP/USP – Stem is green with purple patches. Upper part of stem is cylindrical hairy and the lower part is angular, channeled and less hairy. Leaves are mostly broken and are pale green in color. Leaves are ovate, oblong and irregularly toothed. Water pores are present on teeth and hairs are present on entire lamina especially on veins of lower surface. Flowers are light blue colored, 7mm long with a tubular corolla. Fruit is an inferior capsule and yellowish-green in color and inflated. Seeds are long and broad, reddish-brown colored. Lobelia has a slight irritating smell and taste is unpleasant, acrid and burning.
Morphological features of Lobelia IP – it has thick and thin stems. Thick stem is greenish to yellow, straight, cylindrical and hollow in the middle. Thin stems obtained from twigs are greenish-yellow, cylindrical. Leaves are of two types, lower leaves are bigger, yellowish-green pr greenish-yellow colored and upper leaves are smaller, dull green colored. They are lanceolate to oblong-lanceolate shaped with acute or acuminate apex. Upper surface of leaf is glabrous and lower pubescent (hairy). This drug has tobacco-like odour and acrid nauseating taste. Lobelia pyramidilis is met with as an adulterant of Indian lobelia.
Chemical Constitution Lobelia
Lobelia contains alkaloids, important of them is lobeline. Lobeline on hydrolysis yields acetophenone. Lobelidine, lobelanine, isolobelanine and lobelanidine are the other alkaloids present. It also contains pungent volatile oil, resin gum and fixed oil. Lobeline forms hydrobromide, hydrochloride and methiodide salts.
Indian lobelia contains lobelanidine, nor-lobelanidine and d-lobelanidin 2 and 3. Lobeline is absent. It has two to three times more potent stimulant activity. Use of Indian lobelia is same as that of the above variety.
Health Benefits of Lobelia
As a respiratory stimulant – lobeline present in lobelia acts as a respiratory stimulant. Its blood pressure increasing and respiratory stimulant activity is used for treating asphyxia of the new-born babies; in gas, alcohol and narcotic poisoning and in drowning in water, electric shock and collapse.
Previously fumes of powdered lobelia were used for inhalation. Lobeline and other alkaloids get easily metabolized and hence become inactive when given orally. Therefore, it is administered parenterally. In parenteral form, lobeline hydrochloride is given for resuscitation of new born infants, through umbilical vein.
As a relaxant and a bronchodilator – lobelia is mainly used for the treatment of asthma. It helps clear the mucus from the respiratory tract including lungs, throat and bronchial tubes. Because of its dilatory effect, it is also used for treating respiratory diseases like bronchial asthma and chronic bronchitis and also dyspnoea (shortness of breath).
As a smoking deterrent – Lobelia is used as a smoking deterring agent. It effectively discontinues the smoking addiction. Lobeline has physiological actions similar to nicotine and hence it increases the action of nicotine and smoker gets vomiting sensation and nausea which helps in avoiding further smoking. But later FDA reported that using lobelia as a smoking substitute was not effective in helping people quit or reduce smoking.
Miscellaneous uses of Lobelia
- Lobelia is a cardiovascular stimulant having the effects through carotid chemoreceptor and so it can be used for cardiac ailments.
- Lobeline of lobelia also stimulates cough and pain receptors so can be used for anti-tussive action for treating cough and pneumonia.
- In the 19th century physicians prescribed lobelia to induce vomiting and therefore remove the toxins from the body. Hence lobelia has also gained the name as puke-weed.
- In homeopathy, lobelia is used along with other products for muscle relaxation and in treating skin infections caused by bites or bruises or poison-ivy or ringworm.
- It is also used as a sialagogue, diaphoretic, emetic, expectorant, sedative and stimulant. Also as a cathartic, diuretic and astringent.
- Lobelia is used in ointment to treat rheumatism, pleurisy, tennis elbow, whiplash injuries and boils.
- Lobelia is also burned as an insect-repellant.
Precautions with Lobelia
Adverse effects of lobelia – Toxic doses of lobelia causes vomiting and death ensued by medullary paralysis. Toxic dose causes dry mouth to nausea to convulsion to coma.
- Lobelia may show drug interaction with other products and so you must consult your physician before consuming it.
- It may cause potential effects like profuse sweating, hypothermia, tremors, tachycardia (rapid heart rate), mental confusion and even death. So it should always be taken under the supervision of your health care provider.
- You must not consume lobelia if you are suffering from any sort of heart disease, kidney disease, liver disease or seizure disorder.
- It can worsen the symptoms of ulcer; inflammatory bowel diseases as it irritates the gastro-intestinal tract so do not consume lobelia.
- Pregnant and breastfeeding women must avoid lobelia consumption.
Available forms of lobelia – Lobelia is administered in liquid extracts; tinctures; as a dried herb in capsules and tea; as ointment, lotion or plastics for application on skin.
Lobelia was introduced a long time ago for many purposes like respiratory ailments, muscle disorders, purgative and also it was used for treating syphilis initially. And now it has been famously used for asthma treatment. It has occupied a lot many fields now. But it should be used with caution as it is a potentially toxic drug too.