What are the health benefits of Oregano Oil Extracts?

Oregano Benefits updated on June 1, 2009

Oregano (Origanum vulgare) is native to Europe, the Mediterranean
region and southern and central Asia. Oregano is a derivation from the
Greek origanon "mountain" and the verb ganousthai "delight in". Its leaves
are commonly used in Greek and Italian cuisine.

Oregano oils are rich in carvacrol. Baser KH., Anadolu University,
Turkey, pointed out that carvacrol is responsible for the biological
activities of oregano. Dr. Baser further stated that carvacrol might possibly
offer many health benefits such as antimicrobial, antitumor, antimutagenic,
antigenotoxic, analgesic, antispasmodic, antiinflammatory, angiogenic,
antiparasitic, antiplatelet, AChe inhibitory, antielastase, insecticidal,
antihepatotoxic and hepatoprotective activities and uses such as feed
additive. [2] Oil from oregano leave contains mainly carvacrol, trans-
sabinene hydrate, cis-piperitol, borneol, terpinen-4-ol, and linalool. [A1]

Components
Extracts of oregano leaves contain flavanones, dihydroflavonols, favonols
and flavones. [A2] Water soluble ingredients from the leaves are 4'-O-
beta-D-glucopyranosyl-3',4'-dihydroxybenzyl protocatechuate and 4'-O-
beta-D-glucopyranosyl-3',4'-dihydroxybenzyl 4-O methylprotocatechuate.
[A3]

Oregano oil was mainly composed of monoterpenes and sesquiterpenes.
Monoterpene fraction was found to have linalyl acetate, sabinene, gamma-
terpinene, trans-ocimene, and cis-ocimene. Low percentages of the
phenolic monoterpenoids (thymol and carvacrol) were also detected in the
oil. The main components of sesquiterpenoid were beta-caryophyllene,
caryophyllene oxide, germacrene D, and gamma-elemene. [9]

Potential Health Benefits
Very limited studies have been done for the health benefits of oregano.
Oil extracted from Oregano leaves is found to have antimicrobial activity.
Its ingredient, carvacrol is the most effective in the study. [A1]

Extracts from oregano leaves have antioxidant activities. [A2-A4] Extracts
from the oregano leaves have insecticide activities. Thymol, carvacrol,
(1R)-(+)-alpha-pinene and (1S)-(-)-alpha-pinene were the most toxic. [A5]
Aqueous extract of oregano leaves showed benefits toward diabetic rats. It
lowered the sugar blood level to the normal values in rats. [A6]

Oregano oil may offer benefits on people at risk of bacterial
infection or enteric parasites.

Oregano oil was shown to prevent the growth of E. coli O157:H7 in foods.
[3] Researchers from URI-Campus de Erechim, Brazil, reported the
antimicrobial activity in fresh sausage of marjoram (Origanum majorana
L.) essential oil against several species of bacteria based on an in vitro
study of fresh sausage. [1] Researchers from Avian Sciences Research
Centre, SAC, Edinburgh, demonstrated that oregano oil had limited effects
on intestinal microflora in female chicks. [7] Oregano oil (Oreganum
vulgare) was orally administered to 14 adult patients suffered from enteric
parasites, Blastocystis hominis, Entamoeba hartmanni and Endolimax
nana. After 6 weeks of supplementation with 600 mg emulsified oil of
oregano daily, Entamoeba hartmanni (four cases), Endolimax nana (one
case), and Blastocystis hominis in (eight cases) was undetected in the
patients. Gastrointestinal symptoms also improved in seven of the 11
patients. [8]

Oregano oil may benefit animals at risk of certain types of cancers

Monoterpenes are dietary components found in most of the plant oils and
most of these monterpenes showed antitumor activity in cell or test-tube
studies. Carvacrol, one of the key ingredient from gregano oil was
demonstrated to have antitumor activity in a study of myoblast cells,
CO25. [5]

Interesting…
Oregano oil has been shown to inhibit lipid oxidation in meat during
refrigerated storage. Lipid oxidation causes color changes, texture of the
meat. In some cases, lipid oxidation can be toxic. … Can I consider this as
a kind of health benefit of oregano oil? [6] Anyway, there is also one
article suggesting that oregano oil is anti-inflammatory. [10]

Side Effects
There are no scientific studies about its side effect on human subjects, but
origanum essential oil has been experimented on rat's operant
conditioning behavior. At the high doses the oil caused a depressive
effect (probably due to toxicity) while at the lowest doses they caused
weak or doubtful effects, probably related to a direct action on the central
nervous system. [4] No sure if this side effect also happens in human. If
you experience any side effects because of using oregano extracts or its
oil, you must stop using it and discuss with your doctor.

Reference:

[A1] Santoyo S, Cavero S, Jaime L, Ibañez E, Señoráns FJ, Reglero G.
Supercritical carbon dioxide extraction of compounds with antimicrobial
activity from Origanum vulgare L.: determination of optimal extraction
parameters. J Food Prot. 2006 Feb;69(2):369-75. School: Ciudad
Universitaria de Cantoblanco, Madrid, Spain:[A2] Rodríguez-Meizoso I,
Marin FR, Herrero M, Señorans FJ, Reglero G, Cifuentes A, Ibáñez E.
Subcritical water extraction of nutraceuticals with antioxidant activity from
oregano. Chemical and functional characterization. J Pharm Biomed Anal.
2006 Aug 28;41(5):1560-5. Epub 2006 Feb 20. Instituto de
Fermentaciones Industriales (CSIC), Spain. [A3] Matsuura H, Chiji H,
Asakawa C, Amano M, Yoshihara T, Mizutani J. DPPH radical scavengers
from dried leaves of oregano (Origanum vulgare). Biosci Biotechnol
Biochem. 2003 Nov;67(11):2311-6. Northern Advancement Center for
Science & Technology, Japan. [4] Zheng W, Wang SY. Antioxidant activity
and phenolic compounds in selected herbs. J Agric Food Chem. 2001 Nov;
49(11):5165-70. U. S. Department of Agriculture, USA. [A5] Traboulsi AF,
Taoubi K, el-Haj S, Bessiere JM, Rammal S. Insecticidal properties of
essential plant oils against the mosquito Culex pipiens molestus (Diptera:
Culicidae). Pest Manag Sci. 2002 May;58(5):491-5. Lebanese University,
Beirut, Lebanon. abdallah@cyberia.net.lb. [A6] Lemhadri A, Zeggwagh
NA, Maghrani M, Jouad H, Eddouks M. Anti-hyperglycaemic activity of the
aqueous extract of Origanum vulgare growing wild in Tafilalet region. J
Ethnopharmacol. 2004 Jun;92(2-3):251-6. UFR PNPE, BP 21, Errachidia
52000, Morocco. [1] Busatta C, Vidal RS, Popiolski AS, Mossi AJ, Dariva
C, Rodrigues MR, Corazza FC, Corazza ML, Vladimir Oliveira J, Cansian
RL. Application of Origanum majorana L. essential oil as an antimicrobial
agent in sausage. Food Microbiol. 2008 Feb;25(1):207-11. Epub 2007 Jul
28. [2] Baser KH Biological and pharmacological activities of carvacrol and
carvacrol bearing essential oils. Curr Pharm Des. 2008;14(29):3106-19.
[3] Cross DE, McDevitt RM, Hillman K, Acamovic T. The effect of herbs
and their associated essential oils on performance, dietary digestibility
and gut microflora in chickens from 7 to 28 days of age. Br Poult Sci. 2007
Aug;48(4):496-506. [4] Fundarò A, Cassone MC. Action of essential oils of
chamomile, cinnamon, absinthium, mace and origanum on operant
conditioning behavior of the rat, Boll Soc Ital Biol Sper. 1980 Nov 30;56
(22):2375-80. [5] Zeytinoglu H, Incesu Z, Baser KH. Inhibition of DNA
synthesis by carvacrol in mouse myoblast cells bearing a human N-RAS
oncogene. Phytomedicine. 2003 May;10(4):292-9. [6] Govaris A,
Botsoglou N, Papageorgiou G, Botsoglou E, Ambrosiadis I. Dietary versus
post-mortem use of oregano oil and/or alpha-tocopherol in turkeys to
inhibit development of lipid oxidation in meat during refrigerated storage.
Int J Food Sci Nutr. 2004 Mar;55(2):115-23. [7] Burt SA, Reinders RD.
Antibacterial activity of selected plant essential oils against Escherichia
coli O157:H7. Lett Appl Microbiol. 2003;36(3):162-7. [8] Force M, Sparks
WS, Ronzio RA. Inhibition of enteric parasites by emulsified oil of oregano
in vivo. Phytother Res. 2000 May;14(3):213-4. [9] Afsharypour S, Sajjadi
SE, Erfan-Manesh M. Volatile constituents of Origanum vulgare ssp. viride
(syn. O. heracleoticum) from Iran. Planta Med. 1997 Apr;63(2):179-80.
[10] Bukovská A, Cikos S, Juhás S, Il'ková G, Rehák P, Koppel J. Effects
of a combination of thyme and oregano essential oils on TNBS-induced
colitis in mice. Mediators Inflamm. 2007;2007:23296.