Herbs and plantsOregano — can kitchen oil fight infections?
- Henryk Różański — Rozporządzenie (WE) NR 1924/2006 Parlamentu Europejskiego i Rady z dnia 20 grudnia 2006 r. w sprawie oświadczeń żywieniowych i zdrowotnych dotyczących żywności – znaczenie dla zielarstwa i ziołolecznictwa.
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- Oregano Oil and Harmless Blue Light to Synergistically Inactivate Multidrug-Resistant Pseudomonas aeruginosa. · Front Microbiol 2022
- Antimicrobial and Antibiofilm Efficacy and Mechanism of Oregano Essential Oil Against Shigella flexneri. · Foodborne Pathog Dis 2023
- Savory, Oregano and Thyme Essential Oil Mixture (HerbELICO®) Counteracts Helicobacter pylori. · Molecules 2023
- Development and Evaluation of Microencapsulated Oregano Essential Oil as an Alternative Treatment for Candida albicans Infections. · ACS Appl Mater Interfaces 2024
- Evaluation of the activity and mechanisms of oregano essential oil against PRV in vivo and in vitro. · Microb Pathog 2024
- Oregano essential oil inhibits Candida spp. biofilms. · Z Naturforsch C J Biosci 2021
- Effect of oregano essential oil and carvacrol on Cryptosporidium parvum infectivity in HCT-8 cells. · Parasitol Int 2018
- Oregano oil, carvacrol, and thymol as novel ophthalmic antimicrobials: ocular safety, phenolic interactions, and antibacterial efficacy against clinically relevant ocular pathogens. · Sci Rep 2026
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Henryk Różański lists oregano essential oil among antiviral oils.
- The small amount of oregano in food is no reason to attribute the medicinal properties of oregano essential oil to it.
- Salads with oregano and other ingredients are said to inhibit the growth of bacteria and fungi in the digestive tract.
- Oregano is also listed among plants with a similar action profile to wild thyme.
What the authors write
The small amount of oregano in food is no reason to attribute to it the medicinal properties of oregano essential oil.
Oregano essential oil is on the list of antiviral oils.
Salads with oregano and the other ingredients listed are said to inhibit the growth of bacteria and fungi in the digestive tract.
Oregano is listed among plants with a similar action profile to wild thyme.
Research from PubMed · Europe PMC
We selected 8 studies with the best, positive results. This is a selection, not a full review of all research.
Total number of studies on this topic in PubMed: 356.
Combining oregano oil with blue light effectively reduced drug-resistant bacteria and wound infection in mice.
Aim of the study: Blue light (BL) at 405 nm and oregano essential oil (OEO) have shown bactericidal activity by its own. Here, we demonstrated that the two synergistically killed multidrug-resistant (MDR) Pseudomonas aeruginosa (Pa).
Results: The duo also sufficiently eliminated acute or biofilm-associated infection of open burn wounds in murine without incurring any harmful events in the skin. The synergic bactericide was attributed mainly to the ability of OEO to magnify cytotoxic reactive oxygen species (ROS) production initiated by BL that excited endogenous tetrapyrrole macrocycles in bacteria while completely sparing the surrounding tissues from the phototoxic action. OEO ingredient analysis in combination with microbial assays identified carvacrol and its isomer thymol to be the major phytochemicals that cooperated with BL executing synergic killing. The finding argues persuasively for valuable references of carvacrol and thymol in assessing and standardizing the bactericidal potential of various OEO products.
“Not stated” does not mean nobody paid — the database does not always record it.
Oregano oil killed Shigella flexneri and reduced its biofilm in laboratory tests and in infected meat.
Aim of the study: The aim of this study was to assess the antimicrobial activity of oregano essential oil (OEO) against Shigella flexneri and eradication efficacy of OEO on biofilm. The results showed that the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of OEO against S.
Results: In conclusion, OEO exerts its antimicrobial action effectively and also has a valid scavenging effect on the biofilm of S. flexneri. These findings suggest that OEO has the potential to be used as a natural antibacterial and antibiofilm material in the control of S. flexneri in meat product supply chain, thereby preventing meat-associated infections.
“Not stated” does not mean nobody paid — the database does not always record it.
A mixture of oils containing oregano inhibited the growth of the H. pylori strains tested, and a small study of users recorded eradication rates of up to 90%.
Aim of the study: Fifty percent of the world's population is infected with Helicobacter pylori, which can trigger many gastrointestinal disorders. H.
Results: The minimum concentration required to inhibit in vitro H. pylori growth by HerbELICO® was 4-5% (v/v); 10 min exposure to HerbELICO® was enough to kill off the examined H. pylori strains, while HerbELICO® was able to penetrate through mucin. A high eradication rate (up to 90%) and acceptance by consumers was observed.
“Not stated” does not mean nobody paid — the database does not always record it.
Microparticles containing oregano oil completely inhibited the growth of Candida albicans in culture, and the study also assessed them in a mouse model.
Aim of the study: Vulvovaginal candidiasis (VVC) is characterized as a very common fungal infection that significantly affects women's health worldwide. Essential oils (EOs) are currently being evaluated as an alternative therapy.
Results: albicans biofilms while preserving Lactobacillus species. In in vivo, a single intravaginal application of OEO-KMPs induced a reduction in C. albicans growth, while maintaining Lactobacillus species. In conclusion, this therapeutic approach with OEO-KMPs is promising as a potential alternative or complementary therapy for VVC while preserving vaginal microflora.
“Not stated” does not mean nobody paid — the database does not always record it.
In mice, oregano oil reduced the amount of PRV in tissues, limited tissue damage, and increased survival.
Aim of the study: The Pseudorabies Virus (PRV) leading to pseudorabies and causes huge economic losses in pig industry. The development of novel PRV variations has diminished the efficacy of traditional vaccinations, and there is yet no medication that can stop the spread of PRV infection. Therefore, PRV eradication is challenging.
Results: The current study assessed the anti-pseudorabies virus (PRV) activity of oregano essential oil and explored its mechanisms and most effective components against PRV. Our in vivo findings demonstrated that oregano essential oil could decrease the PRV load in tissues, mitigate tissue lesions, and enhance the survival rate of mice. The potential antiviral mechanism involves augmenting humoral and cellular immune responses in PRV-infected mice. To further investigate the most effective components of oregano essential oil against PRV, an in vitro study was conducted, revealing that oregano essential oil and its main constituents, carvacrol and thymol, all diminished PRV intracellular proliferation in vitro. Carvacrol exhibited the most potent anti-PRV effect, serving as the primary contributor to oregano essential oil's anti-PRV activity.
“Not stated” does not mean nobody paid — the database does not always record it.
Oregano oil inhibited Candida biofilm formation and acted against already formed biofilms.
Aim of the study: Candida spp. can form biofilms on mucosal surfaces and epithelial cells as well as on devices implanted in the body such as catheters and dentures, which are thought to underlie the most recalcitrant infections.
Results: The inhibitory effects of O. onites essential oil, against C. spp., were demonstrated for the first time. It also had antifungal effect on biofilm formation and established biofilm even at MIC level.
“Not stated” does not mean nobody paid — the database does not always record it.
In cell culture, oregano oil reduced the infectivity of Cryptosporidium after the parasite had entered cells, but did not prevent its invasion.
Aim of the study: Cryptosporidium parvum is the second leading cause of persistent diarrhea among children in low-resource settings. This study examined the effect of oregano essential oil (OEO) and carvacrol (CV) on inhibition of C.
Results: Treatment with bioactive after invasion reduced relative C. parvum infectivity in a dose-dependent manner to 55.6±10.4% and 45.8±4.1% at 60 and 30μg/mL of OEO and CV, respectively. OEO and CV are potential bioactives to counteract C. parvum infection in children.
“Not stated” does not mean nobody paid — the database does not always record it.
In laboratory tests, oregano oil inhibited the growth of several bacteria associated with eye infections.
Aim of the study: Bacterial ocular infections are a major cause of vision loss, with antimicrobial resistance limiting treatment efficacy. This study investigated oregano oil and its phenolic components, carvacrol and thymol, as alternative antibacterial agents for ophthalmic use.
Results: Fractional inhibitory concentration (FIC) analysis revealed additive antibacterial interactions (FICI > 0.5-1) between carvacrol and thymol, suggesting these phenolic constituents could serve as adjunct antibacterial agents. Ocular safety was evaluated using the bovine corneal opacity and permeability (BCOP), hen's egg chorioallantoic membrane (HET-CAM), and red blood cell haemolysis assays. At concentrations exceeding MICs (0.5% v/v oregano oil, 0.1% v/v carvacrol, 0.1% w/v thymol), no corneal irritation occurred in the BCOP model, although mild to moderate irritation appeared in conjunctival and membrane assays. Safety index analysis showed oregano oil had the widest safety margin, supporting its potential as an antibacterial for ocular and wider use.
“Not stated” does not mean nobody paid — the database does not always record it.
Perspectives and opinion materials
The content below presents the authors’ opinions, interpretations and hypotheses. It is not treated as equal to scientific studies and systematic reviews.
Pisaczek does not judge who is right. It shows what was written and where to read it. Every sentence above has its source.