flat-leaf parsley

Parsley/Drug Interactions:

  • NoteNote: For some of the following agents, the parsley species was not specified; however, Petroselinum crispum is the most common species used for medicinal purposes.
  • AnalgesicsAnalgesics: Based on animal study, an ethanolic extract of parsley leaves had analgesic effects in the writhing and formalin tests (37).
  • AntibioticsAntibiotics: In vitro study has suggested that parsley, as well as its essential oil and constituents, may have antibacterial effects (10; 11; 166; 167; 168), including effects against foodborne pathogens (169).
  • Anticholinesterase inhibitorsAnticholinesterase inhibitors: Based on in vitro study, parsley extract had acetylcholinesterase inhibitory activity (26).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Parsley has been reported to decrease blood coagulation in humans (55) but in separate human study did not inhibit platelet aggregation, thromboxane A2, factor VII, or other hemostatic variables (170). In animal study, parsley extract inhibited platelet aggregation in vitro and ex vivo and prolonged bleeding time (54), and platelet aggregation inhibitory effects have also been shown in vitro (18).
  • Antidiabetic agentsAntidiabetic agents: Petroselinum crispum is traditionally used to treat diabetes in Turkey. Based on animal study, parsley administration significantly prevented an increase in blood glucose in diabetic rats (8). In rats with streptozotocin (STZ)-induced diabetes, a parsley extract was shown to decrease levels of blood glucose (7). Based on an animal diabetic model, parsley reduced blood glucose, as well as alanine transaminase and alkaline phosphatase levels, and protected against degenerative changes in the liver of the animals (56; 57; 58). Parsley did not protect against diabetes-induced impairments of rat skins (57) or affect the number of secretory granules and cells in islets and other morphologic changes in pancreatic B cells (58).
  • AntihypertensivesAntihypertensives: Some human and animal study suggested that parsley has a diuretic effect (5; 6). According to secondary sources, German physicians routinely prescribe parsley as a diuretic for the treatment of hypertension. However, based on a combination product, Asparagus P?, containing parsley leaf, parsley appears ineffective for blood pressure lowering in hypertensive patients and may increase the risk of adverse effects (171; 172).
  • Anti-inflammatory agentsAnti-inflammatory agents: Based on animal study, an ethanolic extract of parsley leaves (Petroselinum crispum) exhibited protection against carrageenan-induced inflammation and cotton pellet-induced granulomas (32).
  • Antineoplastic agentsAntineoplastic agents: Based on in vitro study, parsley exhibited a marked toxicity against acute lymphoblastic leukemia cell line CEM-C7H2, with a half-maximal inhibitory concentration (IC50) of 3.5mcM/L (9). The IC50 is a measure of the effectiveness of a compound in inhibiting a biological or biochemical function. Based on secondary sources, psoralen, a substance found in parsley, showed some promise as a treatment for cutaneous T-cell lymphoma in preliminary study.
  • Antispasmodic agentsAntispasmodic agents: Based on animal study, the hydroalcoholic extract of parsley seed had a relaxation effect on the ileal contraction, potentially by blocking voltage-gated calcium channels (34).
  • Antiulcer agentsAntiulcer agents: Based on animal study, an ethanolic extract of parsley (Petroselinum crispum), had antiulcerogenic activity (32). Furthermore, ethanol-induced depleted gastric wall mucus and nonprotein sulfhydryl contents were replenished by pretreatment with the parsley extract. Based on in vitro study, aqueous extracts of parsley had bactericidal effects against Helicobacter pylori and inhibited adhesion of the bacteria to animal stomach section (35).
  • Cytochrome P450-metabolized agentsCytochrome P450-metabolized agents: Inhibitory effects of parsley against human cytochrome P450 1A2 in vitro were potentially due to its constituents, such as psoralen, 5-methoxypsoralen, 8-methoxypsoralen, and apigenin (20). Based on animal study, parsley prolonged the action of pentobarbital, and the analgesic actions of aminopyrine and paracetamol; cytochrome P450 in the liver homogenate was decreased (173).
  • DiureticsDiuretics: Some human and animal study suggested that parsley has a diuretic effect (5; 6). Rats, which were offered water with an aqueous extract of parsley, excreted a significantly larger amount of urine per 24 hours than the controls (5). Based on in vitro study, Asparagus P?, a traditional herbal medicine containing parsley, stimulated the metabolism of distal tubule-derived Madin-Darby bovine kidney (MDBK) cells and proximal tubule-derived opossum kidney (OK) cells (174).
  • Drugs used for osteoporosisDrugs used for osteoporosis: Based on a review, parsley can inhibit bone resorption in ovariectomized rats (36).
  • EstrogenEstrogen: Based on both an in vitro and in vivo study, a methanolic extract from the aerial parts of parsley (Petroselinum crispum) showed potent estrogenic activity, which was equal to that of isoflavone glycosides from soybeans (30).
  • Gastrointestinal agentsGastrointestinal agents: Based on animal study, an ethanolic extract of parsley (Petroselinum crispum), had antiulcerogenic activity (32). Furthermore, ethanol-induced depleted gastric wall mucus and nonprotein sulfhydryl contents were replenished by pretreatment with the parsley extract. Based on in vitro study, aqueous extracts of parsley had bactericidal effects against Helicobacter pylori and inhibited adhesion of the bacteria to animal stomach section (35). According to secondary sources, parsley has been reported to reduce indigestion.
  • ImmunosuppressantsImmunosuppressants: Parsley was an ingredient in a syrup shown to increase immune response in children known to catch colds often (27). The role of parsley is unknown.
  • LaxativesLaxatives: In animal study, parsley has shown laxative effects (40).
  • OxytocicsOxytocics: Parsley oil contains two potent uterine stimulants, apiol and myristicin; from the mid-19th Century to the early 20th Century, parsley oil was routinely prescribed to promote uterine contractions. This practice halted in the early 20th Century. In 1968, parsley was reported to have been used as an abortifacient (miscarriage inducer) (3). Therefore, parsley might potentiate the effectiveness of drugs such as pitocin and methergine, which stimulate uterine contractions.
  • Sleep enhancement agentsSleep enhancement agents: Based on animal study, parsley increased ketamine-induced sleeping time (39).

    • Parsley/Herb/Supplement Interactions:

  • NoteNote: For some of the following agents, the parsley species was not specified; however, Petroselinum crispum is the most common species used for medicinal purposes.
  • AnalgesicsAnalgesics: Based on animal study, an ethanolic extract of parsley leaves had analgesic effects in the writhing and formalin tests (37).
  • AntibacterialsAntibacterials: In vitro study has suggested that parsley, as well as its essential oil and constituents, may have antibacterial effects (10; 11; 166; 167; 168) including effects against foodborne pathogens (169).
  • Anticholinesterase inhibitorsAnticholinesterase inhibitors: Based on in vitro study, parsley extract had acetylcholinesterase inhibitory activity (26).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Parsley has been reported to decrease blood coagulation in humans (55) but in separate human study did not inhibit platelet aggregation, thromboxane A2, factor VII, or other hemostatic variables (170). In animal study, parsley extract inhibited platelet aggregation in vitro and ex vivo and prolonged bleeding time (54), and platelet aggregation inhibitory effects have also been shown in vitro (18).
  • Anti-inflammatory herbsAnti-inflammatory herbs: Based on animal study, an ethanolic extract of parsley leaves (Petroselinum crispum) exhibited protection against carrageenan-induced inflammation and cotton pellet-induced granulomas (32).
  • AntineoplasticsAntineoplastics: Based on in vitro study, parsley exhibited a marked toxicity against acute lymphoblastic leukemia cell line CEM-C7H2, with a half-maximal inhibitory concentration (IC50) of 3.5mcM/L (9). The IC50 is a measure of the effectiveness of a compound in inhibiting a biological or biochemical function. Based on secondary sources, psoralen, a substance found in parsley, showed some promise as a treatment for cutaneous T-cell lymphoma in preliminary study.
  • AntioxidantsAntioxidants: Based on human study, parsley increased erythrocyte glutathione reductase and superoxide dismutase activities (4). Based on animal study, an ethanolic extract of parsley protected against D-galactose-induced oxidative stress in the brain (175). A variety of chemical and cell-based antioxidant assays have shown that parsley contains bioactive phytochemical (health-promoting substances) constituents such as apigenin, apiol, and myristicin, which have antioxidant properties (176). Free-radical scavenging and lipid peroxidation protective effects of parsley extracts in vitro (177; 178; 179; 180; 181; 182) and parsley oil (183; 184) have also been examined.
  • AntispasmodicsAntispasmodics: Based on animal study, the hydroalcoholic extract of parsley seed had a relaxation effect on the ileal contraction, potentially by blocking voltage-gated calcium channels (34).
  • Antiulcer herbs and supplementsAntiulcer herbs and supplements: Based on animal study, an ethanolic extract of parsley (Petroselinum crispum) had antiulcerogenic activity (32). Furthermore, ethanol-induced depleted gastric wall mucus and nonprotein sulfhydryl contents were replenished by pretreatment with the parsley extract. Based on in vitro study, aqueous extracts of parsley had bactericidal effects against Helicobacter pylori and inhibited adhesion of the bacteria to animal stomach section (35).
  • Asparagus rootAsparagus root: Based on in vitro study, asparagus root was suggested to enhance the antioxidant effects of parsley; however, data supporting the synergistic effect is lacking (179).
  • CalciumCalcium: Parsley did not affect the absorption of calcium (185). Further details are lacking.
  • Cytochrome P450-metabolized herbs and supplementsCytochrome P450-metabolized herbs and supplements: Inhibitory effects of parsley against human cytochrome P450 1A2 in vitro were potentially due to its constituents, such as psoralen, 5-methoxypsoralen, 8-methoxypsoralen, and apigenin (20). Based on animal study, parsley prolonged the action of pentobarbital, and the analgesic actions of aminopyrine and paracetamol; cytochrome P450 in the liver homogenate was decreased (173).
  • DiureticsDiuretics: Some human and animal study suggested that parsley has a diuretic effect (5; 6). Rats, which were offered water with an aqueous extract of parsley, excreted a significantly larger amount of urine per 24 hours than the controls (5). Based on in vitro study, Asparagus P?, a traditional herbal medicine containing parsley, stimulated the metabolism of distal tubule-derived Madin-Darby bovine kidney (MDBK) cells and proximal tubule-derived opossum kidney (OK) cells (174).
  • GarlicGarlic: Based on in vitro study, parsley reduced the odor of diallyl disulfide, a constituent of garlic (186).
  • Gastrointestinal herbs and supplementsGastrointestinal herbs and supplements: Based on animal study, an ethanolic extract of parsley (Petroselinum crispum), had antiulcerogenic activity (32). Furthermore, ethanol-induced depleted gastric wall mucus and nonprotein sulfhydryl contents were replenished by pretreatment with the parsley extract. Based on in vitro study, aqueous extracts of parsley had bactericidal effects against Helicobacter pylori and inhibited adhesion of the bacteria to animal stomach section (35). According to secondary sources, parsley has been reported to reduce indigestion.
  • HypoglycemicsHypoglycemics: Petroselinum crispum is traditionally used to treat diabetes in Turkey. Based on animal study, parsley administration significantly prevented an increase in blood glucose in diabetic rats (8). In rats with streptozotocin (STZ)-induced diabetes, a parsley extract was shown to decrease levels of blood glucose (7). Based on an animal diabetic model, parsley reduced blood glucose, as well as alanine transaminase and alkaline phosphatase levels, and protected against degenerative changes in the liver of the animals (56; 57; 58). Parsley did not protect against diabetes-induced impairments of rat skins (57) or affect the number of secretory granules and cells in islets and other morphologic changes in pancreatic B cells (58).
  • HypotensivesHypotensives: Some human and animal study suggested that parsley has a diuretic effect (5; 6). According to secondary sources, German physicians routinely prescribe parsley as a diuretic for the treatment of hypertension. However, based on a combination product, Asparagus P?, containing parsley leaf, parsley appears ineffective for blood pressure lowering in hypertensive patients and may increase risk of adverse effects (171; 172).
  • ImmunosuppressantsImmunosuppressants: Parsley was an ingredient in a syrup shown to increase immune response in children known to catch colds often (27). The role of parsley is unknown.
  • IronIron: Based on in vitro study, parsley had iron-chelating effects (180). Parsley inhibited intestinal absorption of iron (187).
  • LaxativesLaxatives: In animal study, parsley has shown laxative effects (40).
  • LysineLysine: Parsley did not affect the absorption of lysine (188). Further details are lacking.
  • Osteoporosis herbs and supplementsOsteoporosis herbs and supplements: Based on a review, parsley can inhibit bone resorption in ovariectomized rats (36).
  • Sleep enhancement herbs and supplementsSleep enhancement herbs and supplements: Based on animal study, parsley increased ketamine-induced sleeping time (39).
  • Uterine stimulantsUterine stimulants: Parsley oil contains two potent uterine stimulants, apiol and myristicin; from the mid-19th Century to the early 20th Century, parsley oil was routinely prescribed to promote uterine contractions. This practice halted in the early 20th Century. In 1968, parsley was reported to have been used as an abortifacient (miscarriage inducer) (3). Therefore, parsley might potentiate the effectiveness of drugs such as pitocin and methergine, which stimulate uterine contractions.

    • Parsley/Food Interactions:

  • Antioxidant-containing foods and culinary herbsAntioxidant-containing foods and culinary herbs: Based on human study, parsley increased erythrocyte glutathione reductase and superoxide dismutase activities (4). Based on animal study, an ethanolic extract of parsley protected against D-galactose-induced oxidative stress in the brain (175). A variety of chemical and cell-based antioxidant assays have shown that parsley contains bioactive phytochemical (health-promoting substances) constituents such as apigenin, apiol, and myristicin, which have antioxidant properties (176). Free-radical-scavenging and lipid peroxidation protective effects of parsley extracts in vitro (177; 178; 179; 180; 181; 182) and parsley oil (183; 184) have also been examined.
  • Calcium-containing foodsCalcium-containing foods: Parsley did not affect the absorption of calcium (185). Further details are lacking.
  • GarlicGarlic: Based on in vitro study, parsley reduced the odor of diallyl disulfide, a constituent of garlic (186).
  • Iron-containing foodsIron-containing foods: Based on in vitro study, parsley had iron-chelating effects (180). Parsley inhibited intestinal absorption of iron (187).
  • VinegarVinegar: Dipping parsley into vinegar solutions had antibacterial effects (189; 98).

    • Parsley/Lab Interactions:

  • CalciumCalcium: Parsley did not affect the absorption of calcium (185). Further details are lacking.
  • Coagulation panelCoagulation panel: Parsley has been reported to decrease blood coagulation in humans (55) but in separate human study did not inhibit platelet aggregation, thromboxane A2, factor VII, or other hemostatic variables (170). In animal study, parsley extract inhibited platelet aggregation in vitro and ex vivo and prolonged bleeding time (54), and platelet aggregation inhibitory effects have also been shown in vitro (18).
  • IronIron: Based on in vitro study, parsley had iron-chelating effects (180). Parsley inhibited intestinal absorption of iron (187).
  • Liver enzymesLiver enzymes: Based on an animal diabetic model, parsley decreased levels of serum alkaline phosphatase and alanine transaminase (7; 56).
  • PotassiumPotassium: Based on animal study, parsley decreased levels of serum potassium (7).
  • Serum estrogenSerum estrogen: An in vitro study and an in vivo study reported that a methanolic extract from the aerial parts of parsley (Petroselinum crispum) showed potent estrogenic activity, which was equal to that of isoflavone glycosides from soybeans (30).
  • Serum glucoseSerum glucose: Based on an animal diabetic model, parsley reduced blood glucose (56; 57; 58; 8; 7). Based on animal study, parsley decreased levels of non-enzymatic glycosylation (7).
  • Sialic acidSialic acid: Based on animal study, parsley decreased levels of sialic acid (7).
  • SodiumSodium: Based on animal study, parsley decreased levels of serum sodium (7).
  • Uric acidUric acid: Based on animal study, parsley decreased levels of uric acid (7).