isopetasin and petasin

Butterbur (Petasites) is an ancient plant which has been used for medical and edible purposes with its spasmolytic agents. However, toxic alkaloid content of the plant limits its direct usage. The paper covers the pyrrolizidine alkaloids (PAs) and butterbur themes in detail in order to display the outline of alkaloid-free plant extract production for medical and edible purposes. The toxic PAs and medicinal constituents of the plant are described with emphasis on analytics, physiological effects and published patent data on alkaloid free extract production. The analytics is based on several commonly used analytical methods including liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry and enzyme linked immunoassay analysis of PAs and N-oxides based on published literature data of butterbur. The analyses of major medicinal constituents of butterbur are given and the physiological effects of these compounds have been discussed to attract attention to the importance of alkaloid-free extract production. The concentration distributions of the medicinal constituents and toxic PAs in different parts of the plant and the outcomes of the published patent data provide comprehensive information for proper plant raw-material selection and production of alkaloid-free butterbur extracts. The review is intended to guide researchers interested in medical plant extracts by providing comprehensive data on the medical plant butterbur and its chemical constituents.

Topics: Analgesics, Non-Narcotic; Animals; Anti-Inflammatory Agents, Non-Steroidal; Carcinogens; Chemical and Drug Induced Liver Injury; Dietary Supplements; Ethnopharmacology; Humans; Parasympatholytics; Petasites; Phytotherapy; Plant Extracts; Plant Leaves; Pyrrolizidine Alkaloids; Rhizome; Sesquiterpenes; Stereoisomerism

Topics: 3T3 Cells; Adipogenesis; Adiposity; Animals; Azo Compounds; Blotting, Western; Coloring Agents; Flowers; Inhibitory Concentration 50; Japan; Mice; Obesity; Petasites; Polyphenols; Pyrrolizidine Alkaloids; Real-Time Polymerase Chain Reaction; Sesquiterpenes; Structure-Activity Relationship

Butterbur root extract with its active ingredients petasin and isopetasin has been used in the prophylactic treatment of migraine for years, while its sites of action are not completely clear. Calcitonin gene-related peptide (CGRP) is known as a biomarker and promoting factor of migraine. We set out to investigate the impact of petasins on the CGRP release from trigeminal afferents induced by activation of the calcium conducting transient receptor potential channels (TRPs) of the subtypes TRPA1 and TRPV1.. We used well-established in vitro preparations, the hemisected rodent skull and dissected trigeminal ganglia, to examine the CGRP release from rat and mouse cranial dura mater and trigeminal ganglion neurons, respectively, after pre-incubation with petasin and isopetasin. Mustard oil and capsaicin were used to stimulate TRPA1 and TRPV1 receptor channels. CGRP concentrations were measured with a CGRP enzyme immunoassay.. Pre-incubation with either petasin or isopetasin reduced mustard oil- and capsaicin-evoked CGRP release compared to vehicle in an approximately dose-dependent manner. These results were validated by additional experiments with mice expressing functionally deleted TRPA1 or TRPV1 receptor channels.. Earlier findings of TRPA1 receptor channels being involved in the site of action of petasin and isopetasin are confirmed. Furthermore, we suggest an important inhibitory effect on TRPV1 receptor channels and assume a cooperative action between the two TRP receptors. These mechanisms may contribute to the migraine prophylactic effect of petasins.

Topics: Animals; Calcitonin; Calcitonin Gene-Related Peptide; Mice; Rats; Sesquiterpenes; Trigeminal Ganglion; TRPA1 Cation Channel; TRPV Cation Channels

It has been shown that a lipophilic CO

Topics: Animals; Guinea Pigs; Humans; Leukotriene Antagonists; Leukotrienes; Oils, Volatile; Petasites; Phytochemicals; Plant Extracts; Plant Leaves; Sesquiterpenes

Topics: Animals; Caco-2 Cells; Humans; Intestinal Absorption; Male; Permeability; Petasites; Phytotherapy; Plant Extracts; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Sesquiterpenes; Solubility

Petasin (1), a natural product found in plants of the genus Petasites, has beneficial medicinal effects, such as antimigraine and antiallergy activities. However, whether or not 1 modulates metabolic diseases is unknown. In this study, the effects of 1 on AMP-activated protein kinase (AMPK), which is considered a pharmacological target for treating metabolic diseases, are described. It was found that an extract of Petasites japonicus produces an increase in the phosphorylation of AMPK in vitro, and the main active compound 1 was isolated. When this compound was administered orally to mice, activation of AMPK in the liver, skeletal muscle, and adipose tissue was observed. Moreover, pretreatment with 1 enhanced glucose tolerance following the administration of a glucose solution to normal mice. The mechanism by which 1 activates AMPK was subsequently investigated, and an increased intracellular AMP/ATP ratio in the cultured cells treated with 1 occurred. In addition, treatment with petasin inhibited mitochondrial respiratory chain complex I. Taken together, the present results indicated that 1 modulates glucose metabolism and activates AMPK through the inhibition of mitochondrial respiration. The preclinical data suggested that petasin (1) could be useful for the treatment of metabolic diseases in humans.

Topics: AMP-Activated Protein Kinases; Animals; Dose-Response Relationship, Drug; Glucose; Japan; Liver; Mice; Mice, Inbred C57BL; Mitochondria; Molecular Structure; Petasites; Rats, Wistar; Sesquiterpenes

To study the chemical constituents of Ligularia intermedia of Shanxi.. The compounds were isolated by column chromatography on silica gel and preparative TLC. The structures were identified by IR, MS, 1D/2DNMR spectral data and X-ray single crystal diffraction and other methods1.. Nine compound were isolated and identified as 8beta-hydroxyeremophil-7(11)-ene-12, 8alpha(4beta, 6alpha)-diolide (1), 8beta-methoxyeremophil-7(11)-ene-12, 8alpha(4beta, 6alpha)-diolide (2), petasin (3), isopetasin (4), liguhodgsonal (5), ligudentatol (6), ligujapone (7), lupeol (8) and lupeol palmitate (9).. Compounds 2, 3, 4, 6, 7 and 9 were isolated from the plant for the first time.

Topics: Asteraceae; Molecular Conformation; Molecular Structure; Plants, Medicinal; Sesquiterpenes; Stereoisomerism

We investigated the mechanisms of action of S-petasin and S-isopetasin, from Petasites formosanus Kitamura which is used as a folk medicine for treating hypertension, tumors, and asthma in Taiwan. The tension changes of tracheal segments were isometrically recorded on a polygraph. S-Petasin and S-isopetasin non-competitively inhibited cumulative histamine-, and carbachol-induced contractions with an exception that S-isopetasin produced a parallel, rightward shift of the concentration-response curve of carbachol in a competitive manner. S-Petasin also non-competitively inhibited cumulative Ca(2+)-induced contractions in depolarized (K+, 60 mM; histamine, 100 microM; or carbachol, 10 microM) guinea-pig tracheas. S-Isopetasin did in depolarized (K+, 60 mM) trachea too. The nifedipine (10 microM)-remaining tension of carbachol (0.2 microM)-induced precontraction was further relaxed by S-petasin or S-isopetasin, suggesting that no matter whether either blocked VDCCs or not, S-petasin or S-isopetasin may have other mechanisms of relaxant action. The relaxant effect of S-petasin or S-isopetasin was unaffected by the presence of propranolol (1 microM), 2',5'-dideoxyadenosine (10 microM), methylene blue (25 microM), glibenclamide (10 microM), N omega-nitro-L-arginine (20 microM), or alpha-chymotrypsin (1 U/ml). However, S-petasin (100-300 microM), but not S-isopetasin, significantly inhibited cAMP-, but not cGMP-dependent PDE activity of the trachealis. The above results reveal that the mechanisms of relaxant action of S-petasin and S-isopetasin may be primarily due to its non-specific antispasmodic and antimuscarinic effects, respectively.

Topics: Animals; Asteraceae; Calcium; Guinea Pigs; In Vitro Techniques; Male; Muscle Relaxation; Neuromuscular Depolarizing Agents; Phosphoric Diester Hydrolases; Plants, Medicinal; Sesquiterpenes; Stereoisomerism; Trachea

Priming of eosinophils with granulocyte-macrophage colony-stimulating factor (GM-CSF) and subsequent stimulation with platelet-activating factor (PAF) or the anaphylatoxin C5a is associated with a rapid production of leukotrienes (LTs) and release of eosinophil cationic protein (ECP).. This study was designed to determine the effects of the sesquiterpene esters petasin, isopetasin and neopetasin on LT generation and ECP release in eosinophils in vitro.. The model of eosinophil activation described above was used to induce LT production and ECP release. Cells were incubated with petasins and control inhibitors prior to priming and stimulation. To analyse intracellular steps of eosinophil activation and determine potential drug targets, some key signalling events were studied. Activity of cytosolic phospholipase A2 (cPLA(2)) was measured by analysing the generation of arachidonic acid (AA). Translocation of 5-lipoxygenase (5-LO) was observed using immunofluorescence microscopy. Intracellular calcium concentrations [Ca2+]i were measured by a bulk spectrofluorometric assay.. Whereas all three compounds inhibited LT synthesis, ECP release from eosinophils was blocked by petasin only, but not isopetasin or neopetasin. Similarly, PAF- or C5a-induced increases in [Ca2+]i were completely abrogated by petasin only, whereas isopetasin and neopetasin had significant lower blocking efficacy. Moreover, only petasin, but not isopetasin or neopetasin, prevented increases in cPLA(2) activity and 5-LO translocation from the cytosolic compartment to the nucleus envelope in calcium ionophore-stimulated eosinophils.. These data suggest that different petasins may at least partially block different intracellular signalling molecules. To reduce LT synthesis, isopetasin and neopetasin may act at the level of or distal to 5-LO. In contrast, petasin may inhibit inflammatory effector functions in human eosinophils by disrupting signalling events at the level of or proximal to phospholipase Cbeta (PLCbeta), besides its potential inhibitory activity within mitogen-activated protein kinase (MAPK) and LT pathways.

Topics: Active Transport, Cell Nucleus; Anti-Inflammatory Agents, Non-Steroidal; Blood Proteins; Calcium; Cell Nucleus; Cells, Cultured; Complement C5a; Cysteine; Cytoplasm; Enzyme Inhibitors; Eosinophil Granule Proteins; Eosinophils; Humans; Inflammation; Leukotriene Antagonists; Leukotrienes; Lipoxygenase Inhibitors; Phospholipases A; Phospholipases A2; Platelet Activating Factor; Ribonucleases; Sesquiterpenes

In the present study, we attempted to compare four petasins, isolated from Petasites formosanus Kitamura, and to look for structure-activity relationships, which may be helpful for synthesizing more active compounds for the treatment of asthma. Four petasins, including petasin, isopetasin, S-petasin and S-isopetasin, concentration-dependently relaxed histamine (10 microM)-, carbachol (0.2 microM)-, KCl (30 mM)-, and leukotriene D4 (10 nM)-induced precontractions of isolated guinea pig trachealis. The IC50 values strongly showed that the relaxant effects of the sulfur-containing petasins, S-petasin and S-isopetasin, were more potent than those of non-sulfur-containing petasins, petasin and isopetasin. S-isopetasin, with IC50 values around 10 microM, selectively relaxed carbachol- and KCl-induced precontractions, and had almost no effects (IC50s > 300 microM) on histamine- and leukotriene D4-induced precontractions. However, S-petasin, with IC50 values about 6-9 microM, non-selectively relaxed the precontractions induced by all these contractile agents. The influence of isomerization of either petasin to isopetasin or S-petasin to S-isopetasin on the relaxant effects is not clear.

Topics: Animals; Asteraceae; Guinea Pigs; In Vitro Techniques; Male; Muscle Relaxation; Sesquiterpenes; Structure-Activity Relationship; Trachea