Oregano
Oregano/Drug Interactions:
AbortifacientsAbortifacients: Oregano has been traditionally used as an abortifacient. Also the over-the-counter herbal combination product Carachipita? (which contains oregano, pennyroyal (Mentha pulegium), yerba de la perdiz (Margyricarpus pinnatus), and guaycuru (Statice brasiliensis)) has been linked with case reports of induced abortion (1), and in female mice, oregano essential oil resulted in an increased rate of cell death in embryos obtained on day 4 of pregnancy (81). Alzheimer's agentsAlzheimer's agents: In vitro, extracts from oregano-related species (Origanum syriacum) inhibited acetylcholinesterase (4). AnthelminthicsAnthelminthics: In vitro, oregano-related species had antiparasitic effects against species such as Schistosoma haematobium (101). AntiangiogenicsAntiangiogenics: Origanum heracleoticum reduced activation of the hypoxia response element of the vascular endothelial growth factor promoter in vitro, suggesting an inhibition of angiogenic activity (102). AntibioticsAntibiotics: Oregano (Origanum vulgare and Origanum onites) essential oil or spice, and the constituents carvacrol, thymol, and eugenol have all demonstrated antibacterial activity in vitro against a wide spectrum of Gram-positive and Gram-negative organisms from food and clinical sources (1990-1999 (103; 104; 105; 106; 16), 2000-2009 (15; 107; 108; 12; 14; 109; 11; 7; 10; 110; 111; 112; 60; 8; 113; 114; 9; 115; 116; 117; 61; 118; 17; 119; 120; 93; 121; 122; 123; 124; 125; 126; 127; 128; 129; 130; 131; 132; 133; 134; 135; 136; 137; 138; 139)), including methicillin-resistant staphylococci (MRSA) (5). In laboratory research, oregano essential oil had additive or synergistic effects with various antibiotics (128; 140; 71). In laboratory research, the minimum inhibitory concentrations of amikacin, streptomycin, and neomycin were increased against Escherichia coli following oral application of oregano essential oil (141). Along with cosmetic ingredients, a combination of essential oils, including mint, oregano, and sage, had antibacterial effects in vitro (71). In laboratory research, oregano in combination with other herbs, such as basil, thyme, or marjoram, showed antibacterial effects (142). In human research, use of an oregano-containing ointment resulted in the isolation of three cultures (19%) testing positive for Staphylococcus aureus vs. seven (41%) in the control group (86). Anticoagulants and antiplateletsAnticoagulants and antiplatelets: In laboratory research, oregano had antithrombin effects (29). The antiplatelet effects of oregano have also been examined in animal models; however, oregano was found to not be as effective as various other plant essential oils (77). AntidiabeticsAntidiabetics: In animal and laboratory research, oregano lowered blood sugar levels and had hypoglycemic effects (78; 43; 44). Other antidiabetic effects, such as inhibition of glycation, amylase, and aldose reductase, have been shown in vitro (2; 46; 44; 48; 49). AntidiarrhealsAntidiarrheals: In animal research, oregano reduced infectious diarrhea due to bacterial pathogens (Lawsonia intracellularis, Escherichia coli) (18; 51). Antifungals, Antifungals: Oregano, related species, and their constituents have displayed antifungal activity against various types of fungi including (but not limited to) Candida albicans, Candida lipolytica, Debaryomyces hansenii, Hansenula anomala, Kloeckera apiculata, Lodderomyces elongisporus, Saccharomyces cerevisiae, Aspergillus parasiticus, Torulopsis glabrata, Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., Fusarium oxysporum f. sp. melonis, Fusarium graminearum, Fusarium verticillioides, and Verticillium dahlia (16; 21; 143; 144; 145; 146; 147; 148; 149; 150; 151; 64; 152; 153; 154; 155; 123; 120; 156; 157; 158; 159; 160; 133; 23; 22; 12). In laboratory research, essential oil from oregano interacted synergistically with amphotericin B and nystatin (161; 162). AntihistaminesAntihistamines: Allergic reaction to oregano has been documented via patch test (84). The potential for allergies to essential oils, including those from oregano, have been discussed by other authors (83; 84). A case report described a 45 year-old man who developed itching and swelling of the lips and tongue, difficulty speaking, progressive upper respiratory difficulty, as well as intense swelling of the face and eyelids on three occasions after eating pizza containing cheese, tomato, and oregano (first episode); meat seasoned with thyme (second episode); and snails seasoned with thyme (third episode) (82). On two occasions, he also developed hypotension. Further challenges with these foods without the herbs had no effect. Skin prick and specific IgE tests for oregano and other herbs of the Lamiaceae family were positive. The patient made a full recovery following treatment with epinephrine, corticosteroids, antihistamines, and fluids. Anti-inflammatoriesAnti-inflammatories: In animal and laboratory research, oregano and related species reduced inflammation and had protective effects against inflammation, particularly in the colon (40; 41; 163; 49). In laboratory research, oregano and its constituents, such as lithospermic acid B, were found to inhibit soybean lipoxygenase (163; 49). AntihypertensivesAntihypertensives: In vitro, a water extract of oregano inhibited angiotensin I-converting enzyme activity (47). AntilipemicsAntilipemics: In hepatotoxin-treated animals, carvacrol normalized levels of total cholesterol, very-low-density lipoprotein (VLDL) cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, phospholipids, and free fatty acids (164). In human research, an aqueous distillate of Origanum onites resulted in improvements in LDL and HDL cholesterol levels, as well as apolipoprotein B and lipoprotein (a) (87). AntimalarialsAntimalarials: In vitro, Origanum compactum essential oil and ethyl acetate extract had antimalarial effects, with an IC50 of 34 and 33mg/mL, respectively (70). AntineoplasticsAntineoplastics: In animal and in vitro research, oregano reduced carcinogenesis and inhibited the number and growth of cancer cells, and it had other antimutagenic effects in vitro (35; 31; 32; 91; 36). AntiprotozoalsAntiprotozoals: In human research, oregano oil completely eradicated various parasites, including Blastocystis hominis, Entamoeba hartmanni, and Endolimax nana (89). In vitro, oregano oils resulted in an inhibition of epimastigote growth and an increase in trypomastigote lysis in Trypanosoma cruzi (165). In animals experimentally infected with Eimeria tenella, oregano oil was found to exert an anticoccidial effects (50). AntispasmodicsAntispasmodics: The antispasmodic activity of oregano-related species and their constituents (thymol and carvacrol) have been investigated (166; 59; 167). These constituents reportedly act as noncompetitive antagonists and are not significantly different from each other (166). AntiviralsAntivirals: In vitro, essential oils and extracts from oregano-related species had antiviral effects (64). AnxiolyticsAnxiolytics: In animal research, carvacrol, a constituent of oregano, displayed anxiolytic effects through GABAergic mechanisms (168). CNS depressantsCNS depressants: In animal research, Origanum essential oils at high doses had a depressive effect on the central nervous system (79). Cytochrome P450 metabolized agentsCytochrome P450 metabolized agents: According to secondary sources, oregano may interact with agents metabolized by the liver's cytochrome P450 enzyme system.Dermatologic agentsDermatologic agents: In vitro, origanoside, isolated from Origanum vulgare, inhibited melanogenesis (73). In human research, an ointment containing oregano improved color and scar assessment, and reduced the number of Staphylococcus aureus-positive cultures (86). However, adverse effects to oregano include allergic contact dermatitis (84). In a clinical trial, pruritus, cellulitis, and mild tenderness occurred in both the oregano and control groups (86). Fertility agentsFertility agents: In animal research, an oregano feed supplement reduced sow mortality and improved reproductive performance (decreased sow culling during lactation, increased number of live-born piglets, decreased stillbirth rate, and increased farrowing rate) (95; 96; 97). However, oregano has been traditionally used as an abortifacient. Also, the over-the-counter herbal combination product Carachipita? (which contains oregano, pennyroyal (Mentha pulegium), yerba de la perdiz (Margyricarpus pinnatus), and guaycuru (Statice brasiliensis)) has been linked with case reports of induced abortion (1), and in female mice, oregano essential oil resulted in an increased rate of cell death in embryos obtained on day 4 of pregnancy (81). FurosemideFurosemide: In vitro, oregano enhanced furosemide permeability across Caco-2 cell monolayers (169). Gastrointestinal agentsGastrointestinal agents: In animal research, oregano reduced infectious diarrhea due to bacterial pathogens (Lawsonia intracellularis, Escherichia coli) (18; 51). In isolated rat fundus, duodenum, and ileum, an aqueous distillate of Origanum onites inhibited contractions; possible active constituents included cis-p-menth-4-ene-1,2-diol and 3,7-dimethyl-1-octen-3,7-diol (170). Hormonal agentsHormonal agents: In laboratory research, oregano was found to contain phytoestrogens and phytoprogestins (171). ImmunosuppressantsImmunosuppressants: In animal research, oregano displayed immunostimulatory effects (65). VasoconstrictorsVasoconstrictors: According to a review, transient receptor potential (TRP) channels TRPA1 and TRPV3 are activated by constituents of oregano, resulting in K(Ca)-dependent, endothelium-dependent vasodilation (172). VasodilatorsVasodilators: According to a review, transient receptor potential (TRP) channels TRPA1 and TRPV3 are activated by constituents of oregano, resulting in K(Ca)-dependent, endothelium-dependent vasodilation (172). Oregano/Herb/Supplement Interactions:
AbortifacientsAbortifacients: Oregano has been traditionally used as an abortifacient. Also, the over-the-counter herbal combination product Carachipita? (which contains oregano, pennyroyal (Mentha pulegium), yerba de la perdiz (Margyricarpus pinnatus), and guaycuru (Statice brasiliensis)) has been linked with case reports of induced abortion (1), and in female mice, oregano essential oil resulted in an increased rate of cell death in embryos obtained on day 4 of pregnancy (81). Alpha-tocopherolAlpha-tocopherol: In turkey meat, a combination of oregano essential oil and alpha-tocopheryl acetate had synergistic effects on its oxidative stability (173). Also, the oregano oil resulted in increased alpha-tocopherol levels in the meat (173; 174). Alzheimer's agentsAlzheimer's agents: In vitro, extracts from oregano-related species (Origanum syriacum) inhibited acetylcholinesterase (4). AnthelminthicsAnthelminthics: In vitro, oregano-related species had antiparasitic effects against species such as Schistosoma haematobium (101). AntiangiogenicsAntiangiogenics: Origanum heracleoticum reduced activation of the hypoxia response element of the vascular endothelial growth factor promoter in vitro, suggesting an inhibition of angiogenic activity (102). AntibacterialsAntibacterials: Oregano (Origanum vulgare and Origanum onites) essential oil or spice, and the constituents carvacrol, thymol, and eugenol have all demonstrated antibacterial activity in vitro against a wide spectrum of Gram-positive and Gram-negative organisms from food and clinical sources (1990-1999 (103; 104; 105; 106; 16), 2000-2009 (15; 107; 108; 12; 14; 109; 11; 7; 10; 110; 111; 112; 60; 8; 113; 114; 9; 115; 116; 117; 61; 118; 17; 119; 120; 93; 121; 122; 123; 124; 125; 126; 127; 128; 129; 130; 131; 132; 133; 134; 135; 136; 137; 138; 139)), including methicillin-resistant staphylococci (MRSA) (5). In laboratory research, oregano essential oil had additive or synergistic effects with various antibiotics (128; 140; 71). In laboratory research, the minimum inhibitory concentrations of amikacin, streptomycin, and neomycin were increased against Escherichia coli following oral application of oregano essential oil (141). Along with cosmetic ingredients, a combination of essential oils, including mint, oregano, and sage, had antibacterial effects in vitro (71). In laboratory research, oregano in combination with other herbs, such as basil, thyme, or marjoram, showed antibacterial effects (142). In human research, use of an oregano-containing ointment resulted in the isolation of three cultures (19%) testing positive for Staphylococcus aureus vs. seven (41%) in the control group (86). Anticoagulants and antiplateletsAnticoagulants and antiplatelets: In laboratory research, oregano had antithrombin effects (29). The antiplatelet effects of oregano have also been examined in animal models; however, oregano was found to not be as effective as various other plant essential oils (77). AntidiarrhealsAntidiarrheals: In animal research, oregano reduced infectious diarrhea due to bacterial pathogens (Lawsonia intracellularis, Escherichia coli) (18; 51). Antifungals, Antifungals: Oregano, related species, and their constituents have displayed antifungal activity against various type of fungi including (but not limited to) Candida albicans, Candida lipolytica, Debaryomyces hansenii, Hansenula anomala, Kloeckera apiculata, Lodderomyces elongisporus, Saccharomyces cerevisiae, Aspergillus parasiticus, Torulopsis glabrata, Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., Fusarium oxysporum f. sp. melonis, Fusarium graminearum, Fusarium verticillioides, and Verticillium dahlia (16; 21; 143; 144; 145; 146; 147; 148; 149; 150; 151; 64; 152; 153; 154; 155; 123; 120; 156; 157; 158; 159; 160; 133; 23; 22; 12). In laboratory research, essential oil from oregano interacted synergistically with amphotericin B and nystatin (161; 162). AntihistaminesAntihistamines: Allergic reaction to oregano has been documented via patch test (84). The potential for allergies to essential oils, including those from oregano, have been discussed by other authors (83; 84). A case report described a 45 year-old man who developed itching and swelling of the lips and tongue, difficulty speaking, progressive upper respiratory difficulty, as well as intense swelling of the face and eyelids on three occasions after eating pizza containing cheese, tomato, and oregano (first episode); meat seasoned with thyme (second episode); and snails seasoned with thyme (third episode) (82). On two occasions, he also developed hypotension. Further challenges with these foods without the herbs had no effect. Skin prick and specific IgE tests for oregano and other herbs of the Lamiaceae family were positive. The patient made a full recovery following treatment with epinephrine, corticosteroids, antihistamines, and fluids. Anti-inflammatoriesAnti-inflammatories: In animal and laboratory research, oregano and related species reduced inflammation and had protective effects against inflammation, particularly in the colon (40; 41; 163; 49). In laboratory research, oregano and its constituents, such as lithospermic acid B, were found to inhibit soybean lipoxygenase (163; 49). AntilipemicsAntilipemics: In hepatotoxin-treated animals, carvacrol normalized levels of total cholesterol, VLDL, LDL, and HDL cholesterol, triglycerides, phospholipids, and free fatty acids (164). In human research, an aqueous distillate of Origanum onites resulted in improvements in LDL and HDL cholesterol levels, as well as apolipoprotein B and lipoprotein (a) (87). AntimalarialsAntimalarials: In vitro, Origanum compactum essential oil and ethyl acetate extract had antimalarial effects, with an IC50 of 34 and 33mg/mL, respectively (70). AntineoplasticsAntineoplastics: In animal and in vitro research, oregano reduced carcinogenesis and inhibited the number and growth of cancer cells and had other antimutagenic effects in vitro (35; 31; 32; 91; 36). AntiparasiticsAntiparasitics: In human research, oregano oil completely eradicated various parasites, including Blastocystis hominis, Entamoeba hartmanni, and Endolimax nana (89). In vitro, oregano oils resulted in an inhibition of epimastigote growth and an increase in trypomastigote lysis in Trypanosoma cruzi (165). In animals experimentally infected with Eimeria tenella, oregano oil was found to exert an anticoccidial effects (50). AntispasmodicsAntispasmodics: The antispasmodic activity of oregano-related species and their constituents (thymol and carvacrol) have been investigated (166; 59; 167). These constituents reportedly act as noncompetitive antagonists and are not significantly different from each other (166). AntiviralsAntivirals: In vitro, essential oils and extracts from oregano-related species had antiviral effects (64). AnxiolyticsAnxiolytics: In animal research, carvacrol, a constituent of oregano, displayed anxiolytic effects through GABAergic mechanisms (168). BasilBasil: In vitro, oregano in combination with other herbs, such as basil, thyme, or marjoram, exhibited antibacterial effects (142). Capsicum oleoresinCapsicum oleoresin: In animal research, a combination of carvacrol, cinnamaldehyde, capsicum oleoresin, and formic acid resulted in a modification of the gastrointestinal ecosystem, stomach contents, and stomach-emptying rate (52). CinnamaldehydeCinnamaldehyde: In animal research, a combination of carvacrol, cinnamaldehyde, capsicum oleoresin, and formic acid resulted in a modification of the gastrointestinal ecosystem, stomach contents, and stomach-emptying rate (52). CopperCopper: Based on the tannin content of oregano, consumption of herbal teas or infusions around meals may inhibit absorption and bioavailability of copper (80). CranberryCranberry: In laboratory research, the combination of cranberry and oregano extracts exhibited antioxidant activity and antibacterial effects as well as improved longevity (195; 196; 3). Cytochrome P450 metabolized agentsCytochrome P450 metabolized agents: According to secondary sources, oregano may interact with agents metabolized by the liver's cytochrome P450 enzyme system.Dermatologic agentsDermatologic agents: In vitro, origanoside, isolated from Origanum vulgare, inhibited melanogenesis (73). In human research, an ointment containing oregano improved color and scar assessment, and reduced the number of Staphylococcus aureus-positive cultures (86). However, adverse effects to oregano include allergic contact dermatitis (84). In a clinical trial, pruritus, cellulitis, and mild tenderness occurred in both the oregano and control groups (86). FenugreekFenugreek: In fenugreek sprouts, oregano extract resulted in stimulation of the phenylpropanoid pathway (197). Fertility agentsFertility agents: In animal research, an oregano feed supplement reduced sow mortality and improved reproductive performance (decreased sow culling during lactation, increased number of live-born piglets, decreased stillbirth rate, and increased farrowing rate) (95; 96; 97). However, oregano has been traditionally used as an abortifacient. Also the over-the-counter herbal combination product Carachipita? (which contains oregano, pennyroyal (Mentha pulegium), yerba de la perdiz (Margyricarpus pinnatus), and guaycuru (Statice brasiliensis)) has been linked with case reports of induced abortion (1) and in female mice, oregano essential oil resulted in an increased rate of cell death in embryos obtained on day 4 of pregnancy (81). Formic acidFormic acid: In animal research, a combination of carvacrol, cinnamaldehyde, capsicum oleoresin, and formic acid resulted in a modification of the gastrointestinal ecosystem, stomach contents, and stomach-emptying rate (52). GarlicGarlic: In animal research, a combination of garlic and oregano was effective in controlling proliferative enteropathy, resulting in reduced diarrhea and prevalence of Lawsonia intracellularis (51). Gastrointestinal agentsGastrointestinal agents: In animal research, oregano reduced infectious diarrhea due to bacterial pathogens (Lawsonia intracellularis, Escherichia coli) (18; 51). In isolated rat fundus, duodenum, and ileum, an aqueous distillate of Origanum onites inhibited contractions; possible active constituents included cis-p-menth-4-ene-1,2-diol and 3,7-dimethyl-1-octen-3,7-diol (170). Green teaGreen tea: In human research, consumption of a bread containing prebiotics, green tea powder, and herbs (including oregano) resulted in increased percentage of CD19 and decreased intercellular adhesion molecule-1 (ICAM-1) and CD3+NK+ (198). Hormonal agentsHormonal agents: In laboratory research, oregano was found to contain phytoestrogens and phytoprogestins (171). HypoglycemicsHypoglycemics: In animal and laboratory research, oregano lowered blood sugar levels and had hypoglycemic effects (78; 43; 44). Other antidiabetic effects, such as inhibition of glycation, amylase, and aldose reductase, have been shown in vitro (2; 46; 44; 48; 49). HypotensivesHypotensives: In vitro, a water extract of oregano has been shown to inhibit angiotensin I-converting enzyme activity (47). ImmunosuppressantsImmunosuppressants: In animal research, oregano displayed immunostimulatory effects (65). IronIron: In human research, oregano was found to inhibit iron absorption (199). Based on the tannin content of oregano, consumption of herbal teas or infusions around meals may inhibit the absorption and bioavailability of iron (80). Lactic acidLactic acid: In vitro, a combination of oregano and cranberry extracts exhibited antimicrobial activity (200). The addition of lactic acid further increased this activity. Methyl gallateMethyl gallate: In vitro, a combination of methyl gallate (Galla Rhois), carvacrol (from oregano), and nalidixic acid had synergistic antibacterial effects (201). Mucuna pruriensMucuna pruriens: Priming Mucuna pruriens seeds with oregano extract resulted in enhanced L-DOPA content (202). PhytoestrogensPhytoestrogens: In laboratory research, oregano was found to contain phytoestrogens and phytoprogestins (171). PrebioticsPrebiotics: In human research, consumption of a bread containing prebiotics, green tea powder, and herbs resulted in increased percentage of CD19 and decreased intercellular adhesion molecule-1 (ICAM-1) and CD3+NK+ (198). In nonsmokers, the ferric-reducing ability of plasma increased, as did concentrations of uric acid and alpha-tocopherol. PhytoprogestinsPhytoprogestins: In laboratory research, oregano was found to contain phytoestrogens and phytoprogestins (171). SedativesSedatives: In animal research, Origanum essential oils at high doses had a depressive effect on the central nervous system (79). Sunflower oilSunflower oil: In vitro, sunflower oil inhibited the antibacterial effects of oregano essential oil (142). Sweet marjoramSweet marjoram: In laboratory research, oregano in combination with other herbs, such as basil, thyme, or marjoram, exhibited antibacterial effects (142). ThymeThyme: In animal research, a combination of thyme and oregano essential oils resulted in decreased inflammation and mortality rate and increased body weight and recovery from induced colitis (40). In laboratory research, oregano in combination with other herbs, such as basil, thyme, or marjoram, showed antibacterial effects (142). VasoconstrictorsVasoconstrictors: According to a review, transient receptor potential (TRP) channels TRPA1 and TRPV3 are activated by constituents of oregano, resulting in K(Ca)-dependent, endothelium-dependent vasodilation (172). VasodilatorsVasodilators: According to a review, transient receptor potential (TRP) channels TRPA1 and TRPV3 are activated by constituents of oregano, resulting in K(Ca)-dependent, endothelium-dependent vasodilation (172). ZincZinc: Based on the tannin content of oregano, consumption of herbal teas or infusions around meals may inhibit absorption and bioavailability of zinc (80). Oregano/Food Interactions:
Beef extractBeef extract: In vitro, beef extract increased the antibacterial effects of oregano essential oil (142). Fenugreek sproutsFenugreek sprouts: In fenugreek sprouts, oregano extract resulted in stimulation of the phenylpropanoid pathway (197). Mucuna pruriensMucuna pruriens: Priming Mucuna pruriens seeds with oregano extract resulted in enhanced L-DOPA content (202). PastaPasta: The addition of oregano both increased and decreased the palatability of pasta with tomato sauce (203). Potato starchPotato starch: In vitro, potato starch inhibited the antibacterial effects of oregano essential oil (142). Sunflower oilSunflower oil: In vitro, sunflower oil inhibited the antibacterial effects of oregano essential oil (142). WineWine: In vitro, wine extracts of oregano leaves exhibited antibacterial effects (204). Oregano/Lab Interactions:
B and T cellsB and T cells: In animal research, oregano displayed immunostimulatory effects, as evidenced by increased proportion of CD4, CD8, MHC class II antigen, and non-T/non-B cells in peripheral blood lymphocytes, and increased the proportion of CD4+ CD8+ double-positive T lymphocytes in peripheral blood and mesenteric lymph nodes (65). Blood glucoseBlood glucose: In animal and laboratory research, oregano lowered blood sugar levels and had hypoglycemic effects (78; 43; 44). Other antidiabetic effects, such as inhibition of glycation, amylase, and aldose reductase, have been shown in vitro (2; 46; 44; 48; 49). Blood pressureBlood pressure: In vitro, a water extract of oregano inhibited angiotensin I-converting enzyme activity (47). Blood vessel diameterBlood vessel diameter: According to a review, transient receptor potential (TRP) channels TRPA1 and TRPV3 are activated by constituents of oregano, resulting in K(Ca)-dependent, endothelium-dependent vasodilation (172). Coagulation panelCoagulation panel: In laboratory research, oregano had antithrombin effects (29). The antiplatelet effects of oregano have also been examined in animal models; however, oregano was found to not be as effective as various other plant essential oils (77). CopperCopper: Based on the tannin content of oregano, consumption of herbal teas or infusions around meals may inhibit absorption and bioavailability of copper (80). C-reactive proteinC-reactive protein: In human research, an aqueous distillate of Origanum onites resulted in improvements in high-sensitivity C-reactive protein (87). Hormone panelHormone panel: Oregano was found to contain phytoestrogens and phytoprogestins (171). Immune panelImmune panel: In animal research, oregano displayed immunostimulatory effects (65). IronIron: In human research, oregano inhibited iron absorption (199). Based on the tannin content of oregano, consumption of herbal teas or infusions around meals may inhibit the absorption and bioavailability of iron (80). Lipid panelLipid panel: In hepatotoxin-treated animals, carvacrol normalized levels of total cholesterol, VLDL, LDL, and HDL cholesterol, triglycerides, phospholipids, and free fatty acids (164). In human research, an aqueous distillate of Origanum onites resulted in improvements in LDL and HDL cholesterol levels, as well as apolipoprotein B and lipoprotein (a) (87). ZincZinc: Based on the tannin content of oregano, consumption of herbal teas or infusions around meals may inhibit the absorption and bioavailability of zinc (80).