Allium cepa

scientific name: 
Allium cepa L.
Botanical family: 

Botanical description

Bulbous and scaly herb; bulbs up to 10 cm in diameter, tunicated.  Leaves basal, up to 40 cm in length, hollow, semi-circular or in cross-section.  Scape up to 60 long.  Flowers numerous, purple or almost white, grouped in large, spherical umbel, with 2 to 3 bracts.  Fruit capsular.



sapito (mouth candidiasis):

  bulb, macerated in water, applied locally 2


  bulb, macerated in water, orally2


  bulb, natural juice, orally1

The bulb of Allium cepa var. aggregatumis widely used for human consumption.

For pneumopathy:

Grind, mash and squeeze one to two bulbs in a cloth.  Mix 15 to 30 mL (1-2 spoons) of juice with honey.  Drink before breakfast once a day for 3 weeks.

For sapito (mouth candidiasis = thrush):

Apply drops of the fresh bulb juice directly on affected area.

According to published and other information:

Use for pneumonia is classified as REC, based on the significant traditional use documented in the TRAMIL surveys, and on available published scientific information.

Should there be a notable worsening of the patient’s condition, or should the respiratorydisorder last more than 5 days or 3 days in case of fever, seek medical attention.

Due to the health risks involved with pneumonia, an initial medical evaluation is recommended.  The use of this resource can be considered complementary to medical treatment, unless it is contraindicated.

Use for sapito (thrush) is classified as REC, based on the significant traditional use documented in the TRAMIL surveys, and on available published scientific information.

For topical application, strict hygiene measures should be observed in order to avoid contamination or additional infection.

The fresh bulb, and the aqueous and ethanolic extracts did not show mutagenicity in the Salmonella typhymurium TA98 model17-18.

The bulb (1 kg/day) administered orally to 18 female young cows caused signs of toxicity after 5 days, characterized by lack of appetite, tachycardia, cardiovascular collapse, reddening of conjunctiva, hemoglobinuria, hemolytic anemia and leukocytosis; this condition was reversed in 17 members of the sample and caused the death of one19.

The ingestion of 150 g of bulb pie (89.7 mg of quercetin), plus 300 mL of black tea (1.4 mg of quercetin), by 20 female and 16 male volunteers during 14 days, to evaluate the effect of flavonoids –mainly quercetin- in the diet, did not report significant damage to DNA in the peripheral lymphocyte model20.

Adverse reactions reported: rhinitis, conjunctivitis and contact dermatitis21.

There is no available information documenting the safety of medicinal use in children or in pregnant or lactating women.

The bulb has been extensively studied and contains, among other components, essential oil: mainly sulfinothioic acid esters3; sulfur compounds: allicin, allium-ene4, allylmethyl disulfide and derivatives, prop-1-ene-1-thiol and derivatives5; flavonoids: crhysanthemin, cyanidin and derivatives, glycosides, paeonidin glucoside and derivatives6, pelargonidin7, quercetin8.

The ethanolic extract (80%) from the fresh bulb did not show antiviral activity in vitro against Herpes simplex9, or against vesicular stomatitis10.

The aqueous extract from the entire fresh plant in vitro (0.3 mL/well) inhibited the growth of Bacillus subtilis, Chromobacterium violaceum, Enterococcus faecalis, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella paratyphi, S. typhi and Staphylococcus aureus but did not inhibit the growth of Klebsiella pneumoniae.  It also inhibited the growth of Aspergillus flavus, A. fumigatus, A. niger and Candida albicans11.

The ethanolic extract (95%) from the bulb in the isolated guinea pig trachea model inhibited histamine- and carbachol-induced contraction of the tracheal muscle, while in the isolated guinea pig ileum model (0.4 mg/mL), it antagonized histamine, serotonin and acetylcholine-induced contractions12.

The juice and the ether extract from the bulb caused an anti-asthmatic effect in vivo through oral administration in guinea pig model (100 mg/kg). When the bronchial obstruction was triggered by allergens and platelet activating factor; however, it did not show an anti-asthmatic effect when the obstruction was induced by histamine or acetylcholine13-14.

The ethanolic extract (95%) from the bulb administered orally to 300 asthmatic adults, male and female, (500 mg/person) reported anti-asthmatic activity12.

The ethanolic extract (1:1) from the bulb applied topically inhibited anti-IgE-induced allergic reactions of the skin in a clinical study with 12 adult individuals15.

The ethanolic extract (95%) from the bulb inhaled by human adult inhibited allergen-induced bronchial obstruction16.


1 GERMOSEN-ROBINEAU L, GERONIMO M, AMPARO C, 1984 Encuesta TRAMIL. enda-caribe, Santo Domingo, Rep. Dominicana.

2 WENIGER B, ROUZIER M, 1986 Enquête TRAMIL. Service Oecuménique d'Entraide SOE, Port au Prince, Haïti.

3 BLOCK E, NAGANATHAN S, PUTMAN D, ZHAO SH, 1992 Allium chemistry: hplc analysis of thiosulfinates from onion, garlic, wild garlic (ramsoms), leek, scallion, shallot, elephant (great-headed) garlic, chive, and Chinese chive. Uniquely high allyl to methyl ratios in some garlic samples. J Agr Food Chem 40(12):2418-2430.

4 WU JB, CHENG YD, HUANG SC, CHANG KH, HSIEH MT, 1992 Quantitative determination of active compounds in Allium genus (Liliaceae) by hplc. China Med Coll J 1(2):123-128.

5 TOKITOMO Y, KOBAYASHI A, 1992 Isolation of the volatile components of fresh onion by thermal desorption cold trap capillary gas chromatography. Biosci Biotech Biochem 56(11):1865-1866.

6 DONNER H, GAO L, MAZZA G, 1997 Separation and characterization of simple and malonylated anthocyanins in red onions, Allium cepa L. Food Res Int 30(8):647-643.

7 FULEKI T, 1969 The anthocyanins of strawberry, rhubarb, radish and onion. J Food Sci 34(4):365-369.

8 PATIL BS, PIKE LM, YOO KS, 1995 Variation in the quercetin content in different colored onions (Allium cepa L.). J Amer Soc Hort Sci 120(6):909-913.

9 VAN DEN BERGHE DA, IEVEN M, MERTENS F, VLIETINCK AJ, LAMMENS E, 1978 Screening of higher plants for biological activities. II. Antiviral activity. J Nat Prod 41(4):463-467.

10 ABOU M, SHIER W, 1990 A simplified plaque reduction assay for antiviral agents from plants. Demonstration of frequent occurrence of antiviral activity in higher plants. J Nat Prod53(2):340-344.

11 SRINIVASAN D, NATHAN S, SURESH T, PERUMALSAMY PL, 2001 Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine. J Ethnopharmacol 74:217-220.

12 SHARMA KC, SHANMUGASUNDRAM SSK, 1979 Allium cepa as an antiasthmatic. RRL Jammu Newsletter 6(2):8.

13 DORSCH W, ETTL M, HEIN G, SCHEFTNER P, WEBER J, BAYER T, WAGNER H, 1987 Antiasthmatic effects of onion. Inhibition of platelet-activating factor-induced bronchial obstruction by onion oils. Int Arch Allergy Appl Immunol 82(3/4):535-536.

14 DORSCH W, ADAM O, WEBER J, ZIEGELTRUM T,1985 Antiasthmatic effects of onion extracts -detection of benzyl- and other isothiocyanates (mustard oil) as antiasthmatic compounds of plant origin. Eur J Pharmacol 107(1):17-24.

15DORSCH W, RING J, 1984 Suppression of immediate and late anti-IgE-induced skin reactions by topically applied alcohol/onion extract. Allergy 39:43-49.

16 DORSCH W, WAGNER H, 1991 New antiasthmatic drugs from traditional medicine? Int Arch Allergy Appl Immunol 94(1/2):262-265.


The information provided is for educational purposes only for the benefit of the general public and health professionals. It is not intended to take the place of either the written law or regulations. Since some parts of plants could be toxic, might induce side effects, or might have interactions with certain drugs, anyone intending to use them or their products must first consult with a physician or another qualified health care professional. TRAMIL has no responsibility whatsoever towards the user for any decision, action or omission made in relation to the information contained in this Pharmacopoeia.