The Common Cold


Causes Other Medicinal Plants
Symptoms References

By: Daniel Ramirez, Katie Souza, and Jeanne Tenorio




            The common cold is an infection of the upper respiratory tract (URI) caused by some 200 different viruses.   The average child will get 5-7 colds each year and the average adult will get 1-2 colds each year.  It is the most “common” illness responsible for lost time at work and school.  Colds are more common in the winter months.  Symptoms last 3-10 days.


  There are many viruses that can cause a cold, but by far the most common is the human rhinovirus (HRV) of which there are 100 known types.  HRV is responsible for at least half of all acute respiratory illnesses. Studies show rhinoviruses are most active in early autumn and late spring. It is spherical in shape, 28-30 nm in diameter, contains a linear RNA genome, and attaches to the folds in the mucous membranes of the nose (hence the name rhinovirus).  HRV is very prolific and once the particles have begun to replicate, high amounts of HRV is secreted in nasal mucous. Rhinoviruses are transmitted from person to person either by direct contact, contact by a healthy person with a contaminated surface, or by airborne particles.  HRV survives for many hours on environmental surfaces. 

            HRV infection is highest among infants and small children.  Researchers believe that this is because antibodies and nasal secretions increase with the primary infection.  These antibodies peak 2-3 days into the illness and then begin to decrease.  Antibodies can be present for a few years after the illness, therefore, helping to prevent reinfection.  Infants and small children have fewer antibodies to draw on and, thus, a higher infection rate.



Artist: Daniel Ramirez

Artist:  Jeanne Tenorio 

There are several other types of viruses that can cause the common cold.  Human coronaviruses (HCV) are responsible for 15-24% of upper respiratory diseases and the chance of reinfection is higher than with rhinovirus. HCV is 80-120 nm in diameter and also contains an RNA genome.  Immunity, if any develops, is short lived.  Stress can exacerbate HCV diseases. 

Other viruses include the Coxsackie viruses, the Echoviruses, the Adenoviruses, the Picornoviruses (rhinovirus is one of these), the Myxoviruses (such as Influenza and Parainfluenza) and Mycoplasma pneumoniae, which is actually a bacteria.


            The period of incubation, the time between exposure and manifestation of symptoms, is usually two or three days.  

            The first symptoms are feelings of roughness or soreness of the throat, development of a nasal discharge, sneezing,  and a sensation of fullness and irritation in the upper respiratory tract.  Headache, general malaise, and chills are often present.  A slight increase in temperature, usually not over 101o F may occur, and gastrointestinal discomfort especially in children.

The cold may be followed by more serious complications – bronchitis, otitis media (middle ear infection), bacterial sinus infection, infection of the mastoid bone, meningitis, bronopenumonia or lobar pneumonia, or exacerbation of other conditions or diseases, such as asthma, arthritis, kidney disease or heart disease.



            Colds are common world wide.  HRV and HCV cause infection in individuals from pole to pole, however, in the temperate regions, the “cold” season correlates with the winter season.

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Scientific Name:  Echinacea purpurea,, Echinacea angustifolia, and Echinacea pallida                           


Common Names:  Purple coneflower, Sampson root, Missouri snakeroot, Rudbekia, Red sunflower

Photo Courtesy of DA Brill, 




Description and Habitat:

            Echinacea is a hardy, herbaceous perennial from the Asteraceae family.  It is often used as an ornamental plant because of its beautiful purple or pink daisy-like flowers.  Echinacea can grow upwards of 3 feet with stout dark green stems and bristly leaves.  It prefers to grow in full sun but can tolerate some shade.  Echinacea is native to the prairies of North America but can be successfully cultivated in the southwest.  


Historical Significance:

            Traditionally, Echinacea was the primary medicinal plant used by the North American Plain Indians.  Echinacea was used to treat everything from sore gums to rattlesnake bites; hydrophobia to gonorrhea.  Echinacea entered mainstream medicine in 1870 when HCF Meyer introduced “Meyer’s Blood Purifier”, a cure-all which contained Echinacea extract.  By the 1920’s Echinacea had been incorporated into the Modern American medicine as a remedy for the common cold.  In recent years, Echinacea has become wildly popular in both the US and Europe, where it has been used as a primary treatment for colds and infections.  However, due to its increasing popularity, Echinacea is now on the medicinal plants “at risk” list created by the United Plant Savers.  



         Echinacea is usually taken at the first sign of a cold and continued for 7 to 14 days. 

         Tinctures:  One of the most popular forms of Echinacea supplement, a tincture may be alcohol or glycerin based.  Standard Dose:  4 mL, 3 times a day

          Capsules:  Another popular form of the herb, capsules normally contain a mixture of plant organs or simply crushed root powder.  

Standard Dose:  ˝-2g, 3 times a day

Tea: Generally the least expensive preparation, a tea can be brewed from the root or a mixture of  plant organs.

Standard Dose: 1/2-2g per cup of tea, 3 times a day  

Powdered Extract:

Standard Dose: 300mg, 3 times a day

Echinacea Juice:

Standard Dose: 2-3 mL, 3 times a day


Active Compounds and Effects:

While no single compound in Echinacea has been solely attributed to its cold fighting ability, many researchers believe that the high-molecular-weight polysaccharides, caffeic acid derivatives, and alkyl amides contribute to its immunostimulatory action.  Echinacea has been shown to increase levels of interferon, which in turn, stimulates phagocytosis (basically healthy cells eating the virally infected cells), cellular respiration, and lymphocyte activation. Cichoric acid (a caffeic acid derivative) has also been shown to inhibit integrase, an important enzyme in viral reproduction.  Echinacea has also exhibited anti-inflammatory action which is often attributed to the alkyl amides and high-molecular-weight polysaccharides.  Much of the research on Echinacea is focused on determining how these immune-boosting compounds work together to shorten the duration of the common cold.  

 Cichoric Acid 

Flowers: 12,000 - 31,000 ppm  Root: 6,000 - 21,000 ppm

Alkyl Amide Derivatives

Root 40 - 1,510 ppm


Polysaccharides (too large to draw)

A Heteroxylan:  Molecular Mass 35,000

An Arabinorhamnogalactan:  Molecular Mass 45,000 

Experimental Data and Other Research:

An ever-increasing amount of evidence shows that Echinacea can shorten the duration of a cold.  The herb can also make the symptoms of the cold milder, and may help to "abort" a new cold.  The most relevant studies are those that test Echinacea on people with cold symptoms.  Many of these clinical studies on Echinacea were conducted in Germany, where Echinacea is a commonly prescribed medicine.  By 1999, at least 29 controlled studies were completed on Echinacea, 14 of which were double blind.   Most of this research examined Echinacea with respect to upper respiratory tract infections (URI's) which are illnesses involving the nose, throat, and bronchi.  In all, these studies make a relatively strong case that Echinacea, in its various forms, can reduce the number of days of sickness and make cold a flu symptoms milder.  Most researchers believe that Echinacea increases the cell-meditated immunity.  This is the part of the immune system involving T-lymphocytes-specialized cells designed to recognize and attach to specific invaders.  They also begin to make copies of themselves once they've spotted their quarry, as well as to release chemicals that act as a rallying cry to the rest of the immune system.  In one study, Echinacea was found to "wake up" the immune system and increase the reaction in tests of cell-mediated immunity.  This distinctly suggests that Echinacea is an immune stimulant.  Additional studies have examined Echinacea's effects on the activity of the immune cells.  One study showed that both injected and oral administration of Echinacea causes an increase in phagocytosis; the swallowing of foreign bodies by certain immune cells.  Researchers are still trying to pinpoint the main chemical compounds responsible for Echinacea's immune boosting effects. 

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Other Medicinal Plants Used to treat Colds

Anise (Pimpinella anisum)

·        Expectorant to get rid of phlegm

·        Anti-viral in large doses

·     Burnet-saxifrage (Pimpinella major) also as expectorant, cough suppressant and widely used to treat sore throat,   bronchitis and hoarseness


Elderberry (Sambucus nigra)

·        Contains 2 compounds active against flu virus

Prevents virus from attacking the respiratory tract


Ephedra (Ephedra sinica)

·        Powerful decongestant

·        Contains ephedrine & pseudoephadrine

May raise blood pressure and cause insomnia


Garlic (Allium sativum)

·        Potent antibiotic and anti-viral

·        Several compounds in garlic contain sulfur

·        Compound known as quercetin retards inflammatory reactions

·        Compound known as allicin, a potent, broad-spectrum antibiotic


  Ginger (Zingiber officinale)

·        Contains nearly a dozen anti-viral compounds

·        Several chemicals including: sesquiterpenes, effective against rhinovirus

Gingerols and shogaols reduce pain and fever, suppress cough, the mild sedative effect encourages rest


Goldenseal (Hydrastis canadensis)

·        Stimulates immune system

·        Antiseptic

·        Increases blood supply to the spleen

·        Compound berberine activates special white blood cells, macrophages, which destroy bacteria, fungi, viruses and tumor cells.  Several other chemicals seem to be of help.


  Licorice (Glycyrrhiza glabra)

·        Antiviral compounds that induce the body to release interferons, our own antiviral constituents


  Marsh mallow (Althaea officinalis)

·        Soothes cough, sore throat

·        Spongy root materials (mucilage) soothes inflamed mucous membranes


Mullein (Verbascum thapsis)

·        Tea of flowers is throat-soothing mucilage

·        A good expectorant

·        Leaf teas are also good


Onion (Allium cepa)

·        Many of the same attributes of garlic

Works well in combination with garlic in food


Osha (Lomatium dissectum)

·        Try chewing on the root.  

·        Native American remedy


Pennyroyal (Hedeoma oblongifoleum)

·        Lowers temperature at first sign of illness

·        Promotes sweating (diaphoretic), eliminating toxins

·        Helps relieve nausea, stomach spasms, especially after vomiting

·        Not to be taken during pregnancy

Found in NM, AZ, CO at 3,000 to 7500 ft.


Purslane (Portulaca oleracea)

·        Rich in the compound glutathione, immune system booster


  Slippery Elm (Ulmus rubra)

·        The bark contains large quantities of a mucilage… throat and respiratory soother

·        Also recognized by the FDA as effective cough suppressant


Stinging nettle (Urtica dioica)  

·    Has been used for centuries to treat nasal and respiratory symptoms such as cough, congestion and runny nose as well

   as asthma, whooping cough and even tuberculosis.

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ATLAS OF VIRUS DIAGRAMS/©1995 CRC Press, Inc. Pages 28-31, 67  


Vol. 1 Pages 410-411, Vol. 3 Pages 1234-1235  

ENCYCLOPEDIA OF LIFE SCIENCES/©2002 Macmillan Publishers Ltd, Nature Publishing Group

                Vol. 16 Pages 409-415

ENCYCLOPEDIA OF VIROLOGY/©1994 Academic Press, Ltd.

                Vol. 1 Pages 258-260, Vol.3 Pages  1253-1259

INFECTIONS OF THE UPPER RESPIRATORY TRACT/© 2002 Neal R. Chamberlain, PhD.                              

"INPR: Echinacea." Retrieved June 30, 2003, from 

"Klinger M.D., Benjamin. "Echinacea." (2003). PDF file retrieved June 30, 2003 from 

McKeown, K.A. (1999). "A Review of the Taxonomy of the Genus Echinacea." p. 482-489. In: J. Janick (ed.), Perspectives On New Crops and   New Uses. 

        ASHS     Press: Alexandria, VA.  

Medicinal Plants of the Mountain West; Michael Moore, 1979 Museum of New Mexico Press

NATURAL TREATMENTS FOR COLDS AND FLUS/ Anna M. Borlon, Elizabeth Collins, ND, Nancy

Berkoff/©1999 Prima Health Publishing.

VITAMIN C THE COMMON COLD AND THE FLU/Linus Paulin/©1976 W.H. Freemman & CO.

The Green Pharmacy; James A. Duke, Ph.D., 1977, The Rodale Press

"The Herb Research Foundation: Herb Information Greenpaper: Echinacea."(2001). Retreived JUne 30, 2003 from 

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Last updated July 18, 2003
For more information contact Dr. Mary O'Connell at

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