Hops

Hops/Drug Interactions:

  • GeneralGeneral: In rats, xanthohumol diminished expression of liver sulfotransferase (Sult1a1) and uridine-diphosphate glucuronosyltransferase (Ugt1a1) (61). It also decreased transcript levels of constitutive androstane receptor (CAR), known to be involved in regulation of drugs and xenobiotics.
  • AcetaminophenAcetaminophen: In mice, hop extracts enhanced and prolonged the analgesic action of paracetamol (acetaminophen); it was proposed that this was achieved by decelerating metabolism and eliminating paracetamol (88; 89). In combination with paracetamol, hop extracts reduced the lipoperoxidation (LPx) intensity, activities of catalase (CAT) and glutathione peroxidase (GSHPx), and glutathione (GSH) content in the liver homogenate. An increase in the aspartate aminotransferase (AST) value was also observed.
  • AnalgesicsAnalgesics: In human research, the hop component of Idrastin? cream was reported to be responsible for analgesic effects (90). In mice, hop extracts enhanced and prolonged the analgesic action of paracetamol (acetaminophen); it was proposed that this was achieved by decelerating metabolism and eliminating paracetamol (88; 89). In combination with paracetamol, hop extracts reduced the lipoperoxidation (LPx) intensity, activities of catalase (CAT) and glutathione peroxidase (GSHPx), and glutathione (GSH) content in the liver homogenate. An increase in the aspartate aminotransferase (AST) value was also observed
  • AntibioticsAntibiotics: In vitro, essential oils and extracts of hops have demonstrated activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Brucella abortus and B. melitensis), and five strains of acne-causing bacteria (12; 91; 92; 93; 94; 95).
  • AntidepressantsAntidepressants: Hops may possess mild central nervous system (CNS) depressant activities (15; 16).
  • AntidiabeticsAntidiabetics: Colupulone from hops has been found to elevate serum glucose levels in diabetic mice, but it has also been shown to either lack effect, or to lower serum glucose levels, in nondiabetic mice (50; 51). In other mouse studies, use of hops lacked significant alteration of the parameters of glucose homeostasis (basal glucose and insulin, insulin-induced hypoglycemia, glycated hemoglobin, and pancreatic insulin concentration) (86). In patients with metabolic syndrome, a combination treatment containing rho-iso-alpha-acids from hops reduced fasting insulin levels (96).
  • AntifungalsAntifungals: In vitro, the essential oil and chloroform extracts of hops demonstrated activity against Trichophyton mentagrophytes var. interdigitale (12).
  • Anti-inflammatoriesAnti-inflammatories: Hop constituents, including humulon and hop bitter acids, have demonstrated anti-inflammatory activity in mice (10; 29). Hop extract decreased inflammatory markers in human research (45). In lipopolysaccharide (LPS)- or tumor necrosis factor (TNF)-alpha-stimulated cultured cells, hop constituents abrogated the inflammatory response (97; 98; 99; 29). In a wound-healing assay, some hop constituents exhibited anti-inflammatory effects (100). In mice with collagen-induced arthritis, rho-iso-alpha-acids from hops inhibited the GSK-3/NF-kappaB pathway and reduced inflammatory markers associated with bone and cartilage degradation, with effects similar to those caused by celecoxib (97). In mice, hop extracts enhanced and prolonged the analgesic action of paracetamol (acetaminophen); it was proposed that this was achieved by decelerating metabolism and eliminating paracetamol (88; 89). In combination with paracetamol, hop extracts reduced the lipoperoxidation (LPx) intensity, activities of catalase (CAT) and glutathione peroxidase (GSHPx), and glutathione (GSH) content in the liver homogenate. An increase in the aspartate aminotransferase (AST) value was also observed.
  • AntilipemicsAntilipemics: In human research, a hop extract caused a decrease in total cholesterol and triglyceride levels in those with a total cholesterol level of 240mg/dL or more, and oxidized LDL antibodies (all p<0.05) (45). In patients with metabolic syndrome, a combination treatment containing hop extract reduced the levels of plasma LDL cholesterol, non-HDL cholesterol, total cholesterol, apolipoprotein (apo) B, triglycerides, and homocysteine; the apo B:apo A1 ratio, the cholesterol:HDL cholesterol ratio, and the triglyceride:HDL cholesterol ratio, and the total LDL particle number and the large HDL particle number (p<0.01) (101; 102; 96).
  • AntineoplasticsAntineoplastics: The bitter acids and flavonoids of hops may possess antiproliferative activity, and hops have been characterized as a "broad-spectrum" cancer chemopreventative agent in vitro (25). In vitro, hop constituents have exhibited anticancer activity (103; 104; 105; 106; 107). Some hop components exhibited antiangiogenic effects, while others exhibited angiogenic effects (100).
  • AntipsychoticsAntipsychotics: Ingestion of hops with antipsychotic agents like phenothiazines has been suggested as possibly increasing the risk of hyperthermia, although human data is lacking. Theoretically, concurrent use may also increase the risk of sedation.
  • Antiulcer agentsAntiulcer agents: Hops have been shown to exhibit stimulant effects on gastric secretions in laboratory animals (87).
  • AntiviralsAntivirals: Xanthohumol from hops enhanced the antiviral effect of interferon-alpha-2b against the bovine viral diarrhea virus, a surrogate of the hepatitis C virus (108).
  • CNS depressantsCNS depressants: Hops may possess mild CNS depressant activity when used alone or concomitantly with other CNS depressants (15; 16). However, a study of a hop/valerian combination reported a lack of potentiation of sedation associated with ethanol; a single dose of a combination product (300mg of hops, 300mg of valerian) lacked sedative effects that were different from placebo after 12 hours (43).
  • ContraceptivesContraceptives: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • Cytochrome P450-metabolized agentsCytochrome P450-metabolized agents: Hop-containing fermented products may inhibit the CYP450 metabolism of various isoenzymes, including CYP2D6, CYP3A4, CYP3A5, CYP3A7, CYP19, and CYP2C9 (56; 57). In vitro and in vivo studies have demonstrated the induction of cytochrome P450 3A and P450 2B by hops (58; 59; 60). In rats, xanthohumol decreased the phenobarbital-inducible cytochrome P450 mRNA levels (61). The induction of hepatic cytochrome P450 3A is attributed to the lupulone constituent of hops. Theoretically, hops may alter the levels and effects of agents metabolized by CYP450.
  • Disulfiram (Antabuse?)Disulfiram (Antabuse?): Some hop preparations may contain high alcohol content and may theoretically elicit a disulfiram reaction.
  • Fertility agentsFertility agents: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • Gastrointestinal agentsGastrointestinal agents: Hops have demonstrated stimulant effects on gastric secretion in laboratory animals (87), but available human research is lacking in this area. Large doses of "spent" hops (used for beer-making) ingested by dogs resulted in vomiting, signs of abdominal pain, hyperthermia, restlessness, panting, and seizures, possibly caused by uncoupling oxidative phosphorylation (53).
  • Hormonal agentsHormonal agents: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies, such as tamoxifen or raloxifene (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • ImmunosuppressantsImmunosuppressants: In vitro, xanthohumol from hops inhibited T cell proliferation, development of interleukin (IL)-2 activated killer cells and cytotoxic T lymphocytes, and Th1 cytokine production (54). Xanthohumol also inhibited monocyte chemoattractant protein-1 and TNF-alpha release in LPS-stimulated RAW 264.7 mouse macrophages and U937 human monocytes (55).
  • InterferonsInterferons: In vitro, xanthohumol (a component of hops) enhanced the antiviral effect of interferon alpha-2b against bovine viral diarrhea virus (108).
  • Metronidazole (Flagyl?)Metronidazole (Flagyl?): A disulfiram reaction may theoretically occur when metronidazole and alcohol are used concomitantly. Due to the high alcohol content in some hops preparations, this combination may theoretically cause such a reaction.
  • SedativesSedatives: According to data from human and animal studies, hops may possess mild CNS depressant activity when used alone or concomitantly with other CNS depressants, such as valerian, although some data are conflicting in this area (15; 16; 43; 109; 110; 111; 8; 9; 17; 112).
  • Sexual stimulantsSexual stimulants: In animals, hop extract appears to have gender-specific libido effects. In hormone-primed female rats, hop extract increased libido (113). In na?ve male rats, however, hop extract exerted an anaphrodisiac effect (28).
  • SteroidsSteroids: In primary cultures of rat Leydig cells, 8-prenylnaringenin and isoxanthohumol differentially suppressed steroidogenesis (114).
  • Thyroid hormonesThyroid hormones: In rats, xanthohumol modulated hepatic expression of genes involved in thyroid hormone distribution and metabolism (61).

    • Hops/Herb/Supplement Interactions:

  • GeneralGeneral: In rats, xanthohumol diminished expression of liver sulfotransferase (Sult1a1) and uridine-diphosphate glucuronosyltransferase (Ugt1a1) (61). It also decreased transcript levels of constitutive androstane receptor (CAR), known to be involved in regulation of drugs and xenobiotics.
  • AnalgesicsAnalgesics: In a human trial, the hop component of Idrastin? cream was reported to be responsible for analgesic effects (90).
  • AntibacterialsAntibacterials: In vitro, essential oils and extracts of hops have demonstrated activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Brucella abortus and B. melitensis), and five strains of acne-causing bacteria (12; 91; 92; 93; 94; 95).
  • AntidepressantsAntidepressants: Hops may possess mild CNS depressant activities (15; 16).
  • AntifungalsAntifungals: In vitro, the essential oil and chloroform extracts of hops demonstrated activity against Trichophyton mentagrophytes var. interdigitale (12).
  • Anti-inflammatoriesAnti-inflammatories: Hop constituents, including humulon and hop bitter acids, have demonstrated anti-inflammatory activity in mice (10; 29). Hop extract decreased inflammatory markers in human research (45). In LPS- or TNF alpha-stimulated cultured cells, hop constituents abrogated the inflammatory response (97; 98; 99; 29). In a wound-healing assay, some hop constituents exhibited anti-inflammatory effects (100). In mice with collagen-induced arthritis, rho-iso-alpha-acids from hops inhibited the GSK-3/NF-kappaB pathway and reduced inflammatory markers associated with bone and cartilage degradation, with effects similar to those caused by celecoxib (97).
  • AntilipemicsAntilipemics: In human research, a hop extract caused a decrease in total cholesterol and triglyceride levels in those with a total cholesterol level of 240mg/dL or more, and oxidized LDL antibodies (all p<0.05) (45). In patients with metabolic syndrome, a combination treatment containing hop extract reduced the levels of plasma LDL cholesterol, non-HDL cholesterol, total cholesterol, apolipoprotein (apo) B, triglycerides, and homocysteine; the apo B:apo A1 ratio, the cholesterol:HDL cholesterol ratio, and the triglyceride:HDL cholesterol ratio, and the total LDL particle number and the large HDL particle number (p<0.01) (101; 102; 96).
  • AntineoplasticsAntineoplastics: The bitter acids and flavonoids of hops may possess antiproliferative activity, and hops have been characterized as a "broad-spectrum" cancer chemopreventative agent in vitro (25). In vitro, hop constituents have exhibited anticancer activity (103; 104; 105; 106; 107). Some hop components exhibited antiangiogenic effects, while others exhibited angiogenic effects (100).
  • AntioxidantsAntioxidants: In vitro, hop constituents exhibited antioxidant effects (1; 115; 91).
  • AntipsychoticsAntipsychotics: Ingestion of hops with antipsychotic agents may increase the risk of hyperthermia, although supporting human data is lacking.
  • Antiulcer agentsAntiulcer agents: Hops have been shown to exhibit stimulant effects on gastric secretions in laboratory animals (87).
  • AntiviralsAntivirals: Xanthohumol from hops enhanced the antiviral effect of interferon-alpha-2b against bovine viral diarrhea virus, a surrogate of the hepatitis C virus (108).
  • AphrodisiacsAphrodisiacs: In animals, hop extract appears to have gender-specific libido effects. In hormone-primed female rats, hop extract increased libido (113). In na?ve male rats, however, hop extract exerted an anaphrodisiac effect (28).
  • CNS depressantsCNS depressants: Hops may possess mild CNS depressant activity when used alone or concomitantly with other CNS depressants (15; 16). However, a study of a hop/valerian combination reported a lack of potentiation of sedation associated with ethanol; a single dose of a combination product (300mg of hops, 300mg of valerian) lacked sedative effects that were different from placebo after 12 hours (43).
  • ContraceptivesContraceptives: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • Cytochrome P450-metabolized herbs and supplementsCytochrome P450-metabolized herbs and supplements: Hop-containing fermented products may inhibit the CYP450 metabolism of various isoenzymes, including CYP2D6, CYP3A4, CYP3A5, CYP3A7, CYP19, and CYP2C9 (56; 57). In vitro and in vivo studies have demonstrated the induction of cytochrome P450 3A and P450 2B by hops (58; 59; 60). In rats, xanthohumol decreased the phenobarbital-inducible cytochrome P450 mRNA levels (61). The induction of hepatic cytochrome P450 3A is attributed to the lupulone constituent of hops. Theoretically, hops may alter the levels and effects of agents metabolized by CYP450.
  • Fertility agentsFertility agents: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • Gastrointestinal agentsGastrointestinal agents: Hops have demonstrated stimulant effects on gastric secretion in laboratory animals (87), but available human research is lacking in this area. Large doses of "spent" hops (used for beer-making) ingested by dogs resulted in vomiting, signs of abdominal pain, hyperthermia, restlessness, panting, and seizures, possibly caused by uncoupling oxidative phosphorylation (53).
  • Hormonal herbs and supplementsHormonal herbs and supplements: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • HypoglycemicsHypoglycemics: Colupulone from hops has been found to elevate serum glucose levels in diabetic mice, but it has also been shown to lack effect, or to lower serum glucose levels, in nondiabetic mice (50; 51). In other mouse studies, hops have not significantly altered the parameters of glucose homeostasis (basal glucose and insulin, insulin-induced hypoglycemia, glycated hemoglobin, and pancreatic insulin concentration) (86). In patients with metabolic syndrome, a combination treatment containing rho-iso-alpha-acids from hops reduced fasting insulin levels (96).
  • ImmunomodulatorsImmunomodulators: In vitro, xanthohumol from hops inhibited T cell proliferation, development of IL-2 activated killer cells and cytotoxic T lymphocytes, and Th1 cytokine production (54). Xanthohumol also inhibited monocyte chemoattractant protein-1 and TNF-alpha release in LPS-stimulated RAW 264.7 mouse macrophages and U937 human monocytes (55).
  • PhytoestrogensPhytoestrogens: Like many other herbs that contain phytoestrogenic compounds, the phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties, with unknown effects on other hormonal therapies (46; 47; 48; 49; 22). Phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • SedativesSedatives: According to data from human and animal studies, hops may possess mild CNS depressant activity when used alone or concomitantly with other CNS depressants, such as valerian, although some data are conflicting in this area (15; 16; 43; 109; 110; 111; 8; 9; 17; 112).
  • SteroidsSteroids: In primary cultures of rat Leydig cells, 8-prenylnaringenin and isoxanthohumol differentially suppressed steroidogenesis (114).
  • Thyroid agentsThyroid agents: In rats, xanthohumol modulated hepatic expression of genes involved in thyroid hormone distribution and metabolism (61).
  • ValerianValerian: The combination of hops and valerian may increase sedation (43; 84). In healthy volunteers, the combination of hops and valerian was found to cause patients to feel less active, reduce alertness, and slow cognitive performance (43). The researchers of this study also recommended caution while driving or operating heavy machinery, because drowsiness or sedation may occur (43).

    • Hops/Food Interactions:

  • Insufficient available evidence.

    • Hops/Lab Interactions:

  • Hormone panelHormone panel: The phytoestrogens in hops may possess estrogen receptor agonist or antagonist properties (46; 47; 48; 49; 22). The phytoestrogens found in hops have been shown to exert direct estrogenic activity in vitro (22).
  • Immune panelImmune panel: In vitro, xanthohumol from hops inhibited T cell proliferation, development of IL-2 activated killer cells and cytotoxic T lymphocytes, and Th1 cytokine production (54). Xanthohumol also inhibited monocyte chemoattractant protein-1 and TNF-alpha release in LPS-stimulated RAW 264.7 mouse macrophages and U937 human monocytes (55).
  • Inflammatory markersInflammatory markers: In human research, a hop extract caused a significant decrease in the complement C3 fraction (p<0.005), C-reactive protein levels (p<0.05), and in the value of interleukin-6 (IL-6) (p<0.05) (45).
  • InsulinInsulin: In patients with metabolic syndrome, a combination treatment containing rho-iso-alpha-acids from hops reduced fasting insulin levels (96).
  • Lipid profileLipid profile: In human research, a hop extract caused a decrease in total cholesterol and triglyceride levels in those with a total cholesterol level of 240mg/dL or more, and oxidized LDL antibodies (all p<0.05)(45). In patients with metabolic syndrome, a combination treatment containing hop extract reduced the levels of plasma LDL cholesterol, non-HDL cholesterol, total cholesterol, apolipoprotein (apo) B, triglycerides, and homocysteine; the apo B:apo A1 ratio, the cholesterol:HDL cholesterol ratio, and the triglyceride:HDL cholesterol ratio, and the total LDL particle number and the large HDL particle number (p<0.01) (101; 102; 96).
  • Serum glucoseSerum glucose: Colupulone from hops has been found to elevate serum glucose levels in diabetic mice, but it has also been shown to have either no effect, or to lower serum glucose levels, in nondiabetic mice (50; 51). In other mouse studies, hops have not altered the parameters of glucose homeostasis (basal glucose and insulin, insulin-induced hypoglycemia, glycated hemoglobin, and pancreatic insulin concentration) (86). In patients with metabolic syndrome, a combination treatment containing rho-iso-alpha-acids from hops reduced fasting insulin levels (96).