Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hydrastis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Photochemistry and photocytotoxicity of alkaloids from Goldenseal (Hydrastis canadensis L.). 2. Palmatine, hydrastine, canadine, and hydrastinine.

Goldenseal is an herb that is widely used in dietary supplements, eye washes, and skin lotions. The presence of Goldenseal root powder in dietary supplements and the topical application of Goldenseal preparations raise the possibility that an adverse phototoxic reaction may result from an interaction between its constituent alkaloids and light in exposed tissues. We have previously shown that berberine, the major alkaloid in Goldenseal powder, in combination with UVA causes DNA damage and cell death in HaCaT keratinocytes [(2001) Chem. Res. Toxicol. 14, 1529]. We have studied the photochemical and photobiological properties of four minor alkaloids found in Goldenseal, namely, hydrastine, palmatine, canadine, and hydrastinine. UVA radiation of palmatine in aqueous solutions generated no (1)O(2), but in CH(2)Cl(2), copious amounts of (1)O(2) were detected (Phi = 0.2). Palmatine also photogenerated oxygen-centered radicals, (*)OH and O(2)(*)(-) in aerated aqueous buffer and acetonitrile, respectively, as detected by the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO). In nitrogen-sparged acetonitrile containing DMPO, we observed the neutral palmatine radical formed by one-electron reduction. UVA irradiation (4 J/cm(2)) of HaCaT keratinocytes in the presence of palmatine (50 microM) resulted in a 50% decrease in cell viability but no DNA damage as measured by the comet assay. UVA irradiation of hydrastine, hydrastinine, or canadine (50 microM) did not cause DNA damage or cell death in keratinocytes. Although palmatine is photoactive, it is present in such small amounts in Goldenseal root powder that the phototoxicity of the herb is most likely due to berberine, the major constituent alkaloid.

Alkaloids↗

Effect of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on digoxin pharmacokinetics in humans.

Phytochemical-mediated modulation of P-glycoprotein (P-gp) and other drug transporters may give rise to many herb-drug interactions. Serial plasma concentration-time profiles of the P-gp substrate, digoxin, were used to determine whether supplementation with goldenseal or kava kava modified P-gp activity in vivo. Twenty healthy volunteers were randomly assigned to receive a standardized goldenseal (3210 mg daily) or kava kava (1227 mg daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (600 mg daily, 7 days) and clarithromycin (1000 mg daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxin, 0.5 mg) was administered p.o. before and at the end of each supplementation and control period. Serial digoxin plasma concentrations were obtained over 24 h and analyzed by chemiluminescent immunoassay. Comparisons of area under the curve (AUC)((0-3)), AUC((0-24)), C(max,) CL/F, and elimination half-life were used to assess the effects of goldenseal, kava kava, rifampin, and clarithromycin on digoxin pharmacokinetics. Rifampin produced significant reductions (p < 0.01) in AUC((0-3)), AUC((0-24)), CL/F, t(1/2), and C(max), whereas clarithromycin increased these parameters significantly (p < 0.01). With the exception of goldenseal's effect on C(max) (14% increase), no statistically significant effects on digoxin pharmacokinetics were observed following supplementation with either goldenseal or kava kava. When compared with rifampin and clarithromycin, supplementation with these specific formulations of goldenseal or kava kava did not appear to affect digoxin pharmacokinetics, suggesting that these supplements are not potent modulators of P-gp in vivo.

Adult↗

Photochemistry and photocytotoxicity of alkaloids from Goldenseal (Hydrastis canadensis L.) 1. Berberine.

Goldenseal is an herb which is widely used for many medical applications such as in eyewashes and skin lotions and which is currently undergoing testing by the National Toxicology Program. The main alkaloid constituent of Goldenseal is berberine. The topical application of Goldenseal or berberine to the skin or eyes raises the possibility that an adverse phototoxic reaction may result from an interaction between the alkaloid and light. We have therefore studied the photochemistry of berberine in different solvents and its phototoxicty to HaCaT keratinocytes. Irradiation of berberine in aqueous solutions does not generate (1)O(2), but in CH(2)Cl(2), (1)O(2) is produced with a quantum yield phi = 0.34. With the aid of the electron paramagnetic resonance (EPR) spin trapping technique and 5,5-dimethyl-1-pyrroline N-oxide (DMPO), we have detected oxygen-centered radicals photogenerated by berberine in water and acetonitrile. In the latter solvent and in the absence of oxygen, the neutral berberine radical formed by one electron reduction was observed. Methanol radicals were detected by EPR in water/alcohol low-temperature glasses irradiated in the berberine long-wavelength absorption band. In such alcoholic glasses, we have also detected an EPR signal from the berberine triplet at 77 K, in contrast to aqueous glasses where neither triplet nor radicals were detectable. Our data show that, although a weak photosensitizer in water, berberine is able to produce both (1)O(2) and radical species in a nonpolar environment. UVA irradiation of HaCaT keratinocytes in the presence of 50 microM berberine resulted in an 80% decrease in cell viability and a 3-fold increase in DNA damage as measured by the Comet assay. These findings suggest that exposure to sunlight or artificial light sources emitting UVA should be avoided when topical preparations derived from Goldenseal or containing berberine are used.

Administration, Topical↗

A reproductive screening test of goldenseal.

BACKGROUND: Goldenseal (Hydrastis canadensis L) is a multi-purpose herb (Hobbs, 1990: Pharm Hist 32:79-82) widely used for its antibiotic properties. It is traditionally contraindicated in pregnancy based on in vivo data but this contraindication has not been confirmed by conventional studies that have been peer reviewed. METHODS: Female rats were dosed by gavage using 65 times the human dose of goldenseal daily on either gestation days (GD) 1-8 or GD 8-15. Controls received an equivalent dose of ethanol. On GD 20, fetuses were weighed and examined for signs of external, internal, or skeletal malformations. Rat fetuses were also explanted on GD 10.5 and cultured with decreasing concentrations of goldenseal for 26 hr. Embryos were examined for growth retardation and malformations. RESULTS: There was no increase in pre- or post-implantation losses. There was no increase in fetal body weight in fetuses exposed to goldenseal. There was no difference in incidence of external or internal malformations. Goldenseal induced toxicity when GD10.5 embryos were cultured for 26 hr in rat serum to which extract was added. CONCLUSIONS: It is likely that poor absorption of goldenseal from the small intestine could explain the discrepancy between the in vivo and in vitro results. It is unlikely that serum concentration from oral treatment could attain the LOEL achieved in vitro. The contrasting results highlight the continuing importance of in vivo work and the necessity of pharmacokinetic data when interpreting in vitro data. The data suggest that goldenseal, at the prescribed human dose, is unlikely to be absorbed to an extent to be unsafe to use in pregnancy despite the apparent cytotoxic effects in vitro. However, these results indicate that pharmacokinetic studies are required to confirm this conclusion.

Abnormalities, Drug-Induced↗

Capillary zone electrophoresis as a tool for the quality control of goldenseal extracts.

The root extracts of goldenseal (Hydrastis canadensis L.) are popular phytomedicines for the treatment of gastrointestinal disorders and upper respiratory tract infections. Here we describe a simple and fast capillary zone electrophoresis (CZE) method with ultraviolet detection at 225 nm for the quantification of the major goldenseal constituents, berberine and hydrastine, in herbal remedies containing goldenseal root extracts. Tritoqualine, an antihistaminic drug with a hydrastine-like phthalidisoquinoline structure, was applied as an internal standard. The running buffer was a 1:5 mixture of 500 mM ammonium acetate (adjusted to pH 3.4 with acetic acid) and methanol. Our newly developed CZE method was validated regarding limit of detection (LOD), limit of quantification, linearity, accuracy and precision. For both berberine and hydrastine, the LOD was 1.0 microg/mL and the linearity was obtained between 2.5 and 500 microg/mL. Using our newly developed method, both the alkaloids could be analysed in herbal remedies containing goldenseal root extracts within 8 min.

Alkaloids↗

In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes.

OBJECTIVES: Phytochemical-mediated modulation of cytochrome P450 (CYP) activity may underlie many herb-drug interactions. Single-time point phenotypic metabolic ratios were used to determine whether long-term supplementation of goldenseal ( Hydrastis canadensis ), black cohosh ( Cimicifuga racemosa ), kava kava ( Piper methysticum ), or valerian ( Valeriana officinalis ) extracts affected CYP1A2, CYP2D6, CYP2E1, or CYP3A4/5 activity. METHODS: Twelve healthy volunteers (6 women) were randomly assigned to receive goldenseal, black cohosh, kava kava, or valerian for 28 days. For each subject, a 30-day washout period was interposed between each supplementation phase. Probe drug cocktails of midazolam and caffeine, followed 24 hours later by chlorzoxazone and debrisoquin (INN, debrisoquine), were administered before (baseline) and at the end of supplementation. Presupplementation and postsupplementation phenotypic trait measurements were determined for CYP3A4/5, CYP1A2, CYP2E1, and CYP2D6 by use of 1-hydroxymidazolam/midazolam serum ratios (1-hour sample), paraxanthine/caffeine serum ratios (6-hour sample), 6-hydroxychlorzoxazone/chlorzoxazone serum ratios (2-hour sample), and debrisoquin urinary recovery ratios (8-hour collection), respectively. The content of purported "active" phytochemicals was determined for each supplement. RESULTS: Comparisons of presupplementation and postsupplementation phenotypic ratio means revealed significant inhibition (approximately 40%) of CYP2D6 (difference, -0.228; 95% confidence interval [CI], -0.268 to -0.188) and CYP3A4/5 (difference, -1.501; 95% CI, -1.840 to -1.163) activity for goldenseal. Kava produced significant reductions (approximately 40%) in CYP2E1 only (difference, -0.192; 95% CI, -0.325 to -0.060). Black cohosh also exhibited statistically significant inhibition of CYP2D6 (difference, -0.046; 95% CI, -0.085 to -0.007), but the magnitude of the effect (approximately 7%) did not appear to be clinically relevant. No significant changes in phenotypic ratios were observed for valerian. CONCLUSIONS: Botanical supplements containing goldenseal strongly inhibited CYP2D6 and CYP3A4/5 activity in vivo, whereas kava inhibited CYP2E1 and black cohosh weakly inhibited CYP2D6. Accordingly, serious adverse interactions may result from the concomitant ingestion of goldenseal supplements and drugs that are CYP2D6 and CYP3A4/5 substrates. Kava kava and black cohosh may interact with CYP2E1 and CYP2D6 substrates, respectively. Valerian appears to be less likely to produce CYP-mediated herb-drug interactions.

Adult↗

Microbial transformation of the phthalideisoquinoline alkaloid, (-)-beta-hydrastine.

The phthalideisoquinoline alkaloid (-)-beta-hydrastine is one of the main active constituents of the medicinal plant, Hydrastis canadensis, which is used in many dietary supplements intended to enhance the immune system. Treatment of hydrastine with the fermentation broth of Polyporous brumalis (ATCC 34487) as a model for mammalian metabolism, gave a new alkaloid, (1S)-hydroxyhydrastine. Structure elucidation was based primarily on NMR and chiroptical studies.

Alkaloids↗

Human cytochrome p450 inhibition and metabolic-intermediate complex formation by goldenseal extract and its methylenedioxyphenyl components.

The concurrent use of herbal medicinals with prescription and over-the-counter drugs carries a risk for unanticipated adverse drug-botanical pharmacokinetic interactions, particularly as a result of cytochrome P450 (P450) inhibition. Extracts of goldenseal (Hydrastis canadensis) containing approximately equal concentrations ( approximately 17 mM) of two methylenedioxyphenyl alkaloids, berberine and hydrastine, inhibited with increasing potency (CYP2C9) diclofenac 4'-hydroxylation, (CYP2D6) bufuralol 1'-hydroxylation, and (CYP3A4) testosterone 6beta-hydroxylation activities in human hepatic microsomes. The inhibition of testosterone 6beta-hydroxylation activity was noncompetitive with an apparent Ki of 0.11% extract. Of the methylenedioxyphenyl alkaloids, berberine (IC50 = 45 microM) was the more inhibitory toward bufuralol 1'-hydroxylation and hydrastine (IC50 approximately 350 microM for both isomers), toward diclofenac 4'-hydroxylation. For testosterone 6beta-hydroxylation, berberine was the least inhibitory component (IC50 approximately 400 microM). Hydrastine inhibited testosterone 6beta-hydroxylation with IC50 values for the (+)- and (-)-isomers of 25 and 30 microM, respectively. For (-)-hydrastine, an apparent Ki value of 18 microM without preincubation and an NADPH-dependent mechanism-based inhibition with a kinactivation of 0.23 min(-1) and a KI of approximately 110 microM were determined. Cytochrome P450 metabolic-intermediate (MI) complex formation could be demonstrated for both hydrastine isomers. With expressed P450 isoforms, hydrastine formed a P450 MI complex with CYP2C9, CYP2D6, and CYP3A4. Coexpression of cytochrome b5 with the P450 isoforms enhanced the rate but not the extent of P450 MI complex formation.

Cytochrome P-450 Enzyme Inhibitors↗