In vivo anti-inflammatory activity of some naturally occurring O- and N-prenyl secondary metabolites.

A series of O- and N-prenyl secondary metabolites of insect, fungal, and plant origin have been evaluated for their topical anti-inflammatory activity using the Croton oil ear test in mice as a model of acute inflammation. Some of the tested compounds revealed an effect (ID50 = 0.31 divided by 0.56 micromol/cm2) comparable with that of the reference non-steroidal anti-inflammatory drug indomethacin (ID50 = 0.23 micromol/cm2).

Steroids with anti-inflammatory activity from Vernonia nigritiana Oliv. & Hiern.

The leaves of Vernonia nigritiana Oliv. & Hiern. (Asteraceae) were investigated for their in vivo topical anti-inflammatory properties, following a bioassay-oriented fractionation approach. Petroleum ether, chloroform and chloroform-methanol extracts inhibited the Croton oil-induced ear dermatitis in mice. The chloroform extract was only about half as active as the non steroidal anti-inflammatory drug indomethacin (ID50=237 and 93 µg/cm(2), respectively). Phytochemical investigation of this extract led to the isolation of nine polyhydroxylated stigmasterol glycosides and six polyhydroxylated stigmasterols. Their structures were elucidated by NMR, MS and chemical methods. Each compound exerted a significant anti-oedema activity, the most active being 1 (3ß-O-ß-D-glucopyranosyloxy-5α-stigmasta-7,9(11),24(28)Z-triene-6ß,16ß,26,29-tetrol) and 3 (3ß-O-ß-D-glucopyranosyloxy-5α-stigmasta-7,9(11),24(28)Z-triene-6ß,16ß,29-triol), only two and five fold less potent than the steroidal drug hydrocortisone (ID50=0.10, 0.21 and 0.04 µmol/cm(2), respectively). Compound 1 (50 µM) also completely inhibited the transcription factor NF-κB in vitro.

Lignan derivatives from Krameria lappacea roots inhibit acute inflammation in vivo and pro-inflammatory mediators in vitro.

The roots of Krameria lappacea are used traditionally against oropharyngeal inflammation. So far, the astringent and antimicrobial properties of its proanthocyanidin constituents are considered to account for the anti-inflammatory effect. The aim of the present study was to characterize pharmacologically a lipophilic extract of K. lappacea roots and several isolated lignan derivatives (1-11) in terms of their putative anti-inflammatory activity. The dichloromethane extract (ID50 77 µg/cm²) as well compounds 1-11 (ID50 0.31-0.60 µmol/cm²) exhibited topical antiedematous properties comparable to those of indomethacin (ID50 0.29 µmol/cm²) in a mouse ear in vivo model. Two of the most potent compounds, 2-(2-hydroxy-4-methoxyphenyl)-5-(3-hydroxypropyl)benzofuran (5) and (+)-conocarpan (7), were studied regarding their time-dependent edema development and leukocyte infiltration up to 48 h after croton oil-induced dermatitis induction, and they showed activity profiles similar to that of hydrocortisone. In vitro studies of the isolated lignan derivatives demonstrated the inhibition of NF-κB, cyclooxygenase-1 and -2, 5-lipoxygenase, and microsomal prostaglandin E2 synthase-1 as well as antioxidant properties, as mechanisms possibly contributing to the observed in vivo effects. The present findings not only support the ethnopharmacological use of K. lappacea roots but also reveal that the isolated lignan derivatives contribute strongly to the anti-inflammatory activity of this herbal drug.

Topical anti-inflammatory activity of boropinic acid and its natural and semi-synthetic derivatives.

Boropinic acid is a natural isopentenyloxycinnamic acid extracted from the aerial parts of Boronia pinnata Sm. (Rutaceae) with soybean 5-lipoxygenase inhibitory activity. In this paper the topical anti-inflammatory activity of boropinic acid and some of its natural and semi-synthetic derivatives was evaluated using the Croton oil ear test in mice as a model of acute inflammation. Some of the tested compounds (15, 17, 19, 20) revealed an effect comparable (ID(50)=0.18÷0.72µmol/cm(2)) to that of the reference drug indomethacin (ID(50)=0.23µmol/cm(2)), a non-steroidal anti-inflammatory drug.

Antiinflammatory activity of coumarins from Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae).

Four coumarin derivatives [selidinin 1, (+)-praeruptorin A 2, visnadin 3 and (R)-(+)-7-(2',3'-epoxy-3'-methylbutoxy)-coumarin 4] were isolated from the aerial parts of Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae). This is the first report on the identification of these compounds in the Ligusticum genus. Their topical antiinflammatory activity was evaluated as the inhibition of croton oil-induced ear dermatitis in mice. Each compound (0.3 µmol/cm(2) ) induced a significant oedema reduction and compound 4 exerted an effect similar to that of the equimolar dose of the reference drug indomethacin.

Comparative topical anti-inflammatory activity of cannabinoids and cannabivarins.

A selection of seven phytocannabinoids representative of the major structural types of classic cannabinoids and their corresponding cannabivarins was investigated for in vivo topical anti-inflammatory activity in the Croton oil mouse ear dermatitis assay. Differences in the terpenoid moiety were far more important for anti-inflammatory activity than those at the C-3 alkyl residue, suggesting the involvement not only of cannabinoid receptors, but also of other inflammatory end-points targeted by phytocannabinoids.

Topical anti-inflammatory activity of Eupatilin, a lipophilic flavonoid from mountain wormwood ( Artemisia umbelliformis Lam.).

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is the major lipophilic flavonoid from Artemisia umbelliformis Lam. and Artemisia genipi Weber, two mountain wormwoods used for the production of the celebrated alpine liqueur genepy. The topical anti-inflammatory activity of eupatilin was investigated using the inhibition of the Croton-oil-induced dermatitis in the mouse ear as the end point. The oedematous response and the leukocyte infiltration were evaluated up to 48 h after the induction of phlogosis, comparing eupatilin with hydrocortisone and indomethacin as representatives of steroid and non-steroid anti-inflammatory drugs, respectively. At maximum development, eupatilin significantly reduced edema in a dose-dependent manner (ID(50) = 0.28 micromol/cm(2)), showing an anti-inflammatory potency comparable to that of indomethacin (ID(50) = 0.26 micromol/cm(2)) and only 1 order of magnitude lower than that of hydrocortisone (ID(50) = 0.03 micromol/cm(2)). Within 48 h, eupatilin (0.30 micromol/cm(2)) caused a global inhibition of the oedematous response (42%) higher than that of an equimolar dose of indomethacin (18%) and fully comparable to that of 0.03 micromol/cm(2) of hydrocortisone (55%). Moreover, the effect of eupatilin on the granulocytes infiltrate (32% inhibition) was similar to that of indomethacin (35% inhibition) and comparable to that of hydrocortisone (42% reduction), as confirmed by histological analysis. When our results are taken together, they show that eupatilin is endowed with potent in vivo topical anti-inflammatory activity, qualitatively similar to that of hydrocortisone and intermediate in terms of potency between those of steroid and non-steroid drugs.

In vivo anti-inflammatory and in vitro antioxidant activities of Mediterranean dietary plants.

Five hydroalcoholic extracts of edible plants from Calabria region (Italy) used in local traditional medicine for the treatment of inflammatory diseases were evaluated for their in vivo topical anti-inflammatory activity (inhibition of croton oil-induced ear oedema in mice) and in vitro antioxidant and antiradical properties (inhibition of linoleic acid oxidation and bovine brain liposomes peroxidation, DPPH radical scavenging). All the extracts showed an anti-inflammatory effect: 300 microg/cm(2) provoked oedema reductions ranging from 21 to 27%. All the extracts exerted also radical scavenging and/or antioxidant properties, the most active plant being Mentha aquatica L. (Lamiaceae) which contained the highest amount of phenolics (337 mg/g) and of flavonoids (15.75 mg/g). Moreover, the content and the composition of sterols were assessed by GC-MS in the examined plants Borago officinalis L. (Boraginaceae) contained the highest number of sterols.

Evaluation of the topical anti-inflammatory activity of ginger dry extracts from solutions and plasters.

In this study the skin permeation and the topical anti-inflammatory properties of ginger extracts were investigated. A commercial ginger dry extract (DE) and a gingerols-enriched dry extract (EDE) were evaluated for their in vivo topical anti-inflammatory activity by inhibition of Croton oil-induced ear oedema in mice. Furthermore, the feasibility of an anti-inflammatory plaster containing DE or EDE was evaluated. Since the in vivo activity was evaluated in mice, the ex vivo skin permeation study was performed by using mouse skin or human epidermis. The DE from the acetonic solution exerted a dose-dependent topical anti-inflammatory activity (ID (50) = 142 microg/cm (2)), not far from that of the potent reference substance indomethacin (ID (50) = 93 microg/cm (2)). Similarly, the EDE induced a dose-dependent oedema reduction though its potency (ID (50) = 181 microg/cm (2)) was slightly lower than that of DE. Increase of the 6-gingerol concentration in the extract did not improve the anti-inflammatory activity. The medicated plasters, containing 1 mg/cm (2) of the commercial DE or EDE, had good technological characteristics and exerted a significant antiphlogistic effect, too. By using the plaster containing EDE, the 6-gingerol amount that permeated through human epidermis was 6.9 microg/cm (2) while the amount that passed through mouse skin was 22.1 microg/cm (2). Nevertheless, the amounts of 6-gingerol permeated through human epidermis and mouse skin in the early period (8h) were comparable (p > 0.3). This preliminary result suggests that the anti-inflammatory effect observed in mice could also be exerted in humans.

Topical antiinflammatory activity of an innovative aqueous formulation of actichelated propolis vs two commercial propolis formulations.

A novel aqueous commercial formulation of a new hydrophilic propolis product (Actichelated((R)) Propolis, contained in 'LeniGola PropolEffect Spray Senza Alcohol'; Pharbenia, Milan, Italy) was evaluated for its topical antiinflammatory activity in comparison with a hydroglyceric propolis spray solution ('Propoli LeniGola Spray Senza Alcool'; Pharbenia, Milan, Italy) and a hydroalcohol preparation ('Propoli LeniGola Spray Forte'; Pharbenia, Milan, Italy). Actichelated propolis (Actimex, Trieste, Italy) is a multicomposite material obtained with a patented technology, mechano-chemical activation, which application led to a new hydrosoluble form of propolis. Each propolis preparation provoked a dose-dependent inhibition of the croton oil-induced ear oedema in mice. Considering the administered doses of flavonoids, 'LeniGola PropolEffect Spray Senza Alcool' (ID(50) = 13.6 microL/cm(2), corresponding to 13.6 microg flavonoids/cm(2)) is slightly more active than the hydroglyceric formulation 'Propoli LeniGola Spray' (ID(50) = 13.7 microL/cm(2), corresponding to 20.6 microg flavonoids/cm(2)) and six times more active than the hydroalcohol preparation 'Propoli LeniGola Spray Forte' (ID(50) = 5.5 microL/cm(2), corresponding to 82.5 microg flavonoids/cm(2)). As a reference, 15 microL/cm(2) of the commercial sprays Tantum Verde and Froben, containing 37.5 or 45 microg of the non-steroidal antiinflammatory drugs benzidamine hydrochloride or flurbiprofen, induced 18% and 35% oedema inhibition, respectively.

Topical anti-inflammatory activity of extracts and compounds from Hypericum perforatum L.

Three preparations of Hypericum perforatum L. (a hydroalcoholic extract, a lipophilic extract and an ethylacetic fraction) and the pure compounds hypericin, adhyperforin, amentoflavone, hyperoside, isoquercitrin, hyperforin dicyclohexylammonium (DHCA) salt and dicyclohexylamine were evaluated for their topical anti-inflammatory activity. H. perforatum preparations provoked a dose-dependent reduction of Croton-oil-induced ear oedema in mice, showing the following rank order of activity: lipophilic extract > ethylacetic fraction > hydroalcoholic extract (ID50 (dose that inhibited oedema by 50%) 220, 267 and >1000 microg cm(-2), respectively). Amentoflavone (ID50 0.16 micromol cm(-2)), hypericin (ID50 0.25 micromol cm(-2)), hyperforin DHCA salt (ID50 0.25 micromol cm(-2)) and adhyperofrin (ID50 0.30 micromol cm(-2)) had anti-inflammatory activity that was more potent or comparable to that of indometacin (ID50 0.26 micromol cm(-2)), whereas isoquercitrin and hyperoside were less active (ID50 about 1 micromol cm(-2)). As dicyclohexylamine alone was inactive, the effect of hyperforin DHCA salt can be attributed completely to the phloroglucinol moiety. The pharmacological activity and phytochemical profile of the tested extracts and fraction suggest that different constituents are involved in the topical antiphlogistic property of H. perforatum in-vivo.

Characterization of topical antiinflammatory compounds in Rosmarinus officinalis L.

The topical antiinflammatory activity of three extracts at increasing polarity (n-hexane, chloroform, and methanol) from the leaves of Rosmarinus officinalis L. (Labiatae) has been tested using the croton oil ear test in mice. Both the n-hexane and the chloroform (CE-1) extracts from the leaves showed a dose-dependent activity, the last one possessing an antiinflammatory potency similar to that of indomethacin, the nonsteroidal antiinflammatory drug used as a reference drug (ID50 = 83 and 93 microg/cm2, respectively). The bioassay-oriented fractionation of CE-1 led to the identification of tritepenes, ursolic acid, oleanolic acid, and micromeric acid as the main antiinflammatory principles. Furthermore, the CE-1 extract obtained from the residue of the steam distillation of the leaves (extract A) showed the same antiinflammatory potency of CE-1, suggesting this waste product as a source of antiinflammatory products.

Anti-inflammatory activity of two diterpenes of Hyptis suaveolens from El Salvador.

Separation and isolation of the two main compounds suaveolol and methyl suaveolate from leaves of chichinguaste (Hyptis suaveolens Poit., Lamiaceae) could be achieved by means of repeated column chromatography and repeated preparative thin layer chromatography. Their chemical structures were approved by MS, 1H NMR, 13C NMR and 2D-NMR experiments. The anti-inflammatory activity of the two compounds was tested for the first time as inhibition of croton oil-induced dermatitis of the mouse ear. Suaveolol and methyl suaveolate showed nearly the same dose-dependent topical anti-inflammatory activity, only two to three times lower than that of the reference drug indomethacin. The anti-inflammatory properties of these compounds could contribute to the antiphlogistic activity of extracts of Hyptis species and confirm the rational use of Hyptis suaveolens extracts in dermatological diseases.

Fatty acids profile and antiinflammatory activity of Nonea setosa R. et S.

In order to verify the antiinflammatory properties of Nonea setosa R. et S. (Fam. Boraginaceae) and to identify the relevant active principles, aerial parts of this plant were extracted with increasing polarity solvents. The antiinflammatory activity was investigated by a bioassay-oriented fractionation using the inhibition of the croton oil-induced ear oedema in mice as an experimental model of inflammation. GC-MS analysis of the most active fraction revealed the presence of high amounts of polyunsaturated fatty acids.

New sesquiterpene lactones from Arnica tincture prepared from fresh flowerheads of Arnica montana.

Investigation of an ethanolic extract prepared from fresh Arnica montana flowers afforded three new 1,5- trans-guaianolides, of which 11alpha,13-dihydro-2-O-tigloylflorilenalin and the respective 2-O-isovaleryl derivative are reported for the first time. Additionally, three new and one known 2beta-ethoxy-2,3-dihydrohelenalin esters were isolated. GC/MS studies of the extract after a two year storage at 4 degrees C demonstrated that the latter were artefacts that had been formed by addition of ethanol to the cyclopentenone structure of helenalin. Formation of these adducts gave compounds possessing an inhibitory activity comparable to that of 11alpha,13-dihydrohelenalin derivatives in the NF-kappaB EMSA and the IL-8 ELISA in vitro assays as well as in the in vivo croton oil-induced mouse ear edema test for one adduct, namely 2beta-ethoxy-6-O-acetyl-2,3-dihydrohelenalin. As expected, 6-O-(2-methylbutyryl)- and 6-O-methacryloyl-helenalin exhibited a stronger activity in the NF-kappaB EMSA and IL-8 ELISA. Sesquiterpene lactones seem to be the most important NF-kappaB inhibiting compounds in the Arnica extract. Bioguided fractionation using the luciferase reporter gene assay resulted in the isolation of only moderately active compounds, such as 6-acetoxy-2,2-dimethylchroman-4-one and 10-acetoxy-8,9-epoxythymol isobutyrate.

Glaucopines A and B, new cyathane diterpenes from the fruiting bodies of Sarcodon glaucopus.

Glaucopine A (1) and B (2), two new cyathane diterpenes, have been isolated from the mushroom Sarcodon glaucopus: their structures have been determined on the basis of spectral data. Their topical anti-inflammatory activity was evaluated using the Croton oil ear test in mice: compounds 1 and 2 (1 micromol/cm2) provoked edema reduction (62 % and 55 %, respectively) similar to that induced by the reference non-steroidal anti-inflammatory drug, indomethacin (0.3 micromol/cm2, 61 % edema reduction).

Synthesis and biological evaluation of new phenidone analogues as potential dual cyclooxygenase (COX-1 and COX-2) and human lipoxygenase (5-LOX) inhibitors.

A new series of potential human 5-LOX inhibitors structurally related to the 1-phenyl-3-pyrazolidinone (phenidone, 2) has been synthesized and the activity against COX-1, COX-2, and human 5-LOX enzymes has been evaluated. In contrast with literature data, we observed that phenidone resulted to be inactive against human 5-LOX, while retains its activity against cyclooxygenases in a micromolar range. The present results suggest that the substitution of the amino function at the 4-position is detrimental in terms of activity toward COX-1 and COX-2, while the presence of a double bond at the 4,5-position does not alter the biological profile against COX. The absence of activity vs. human 5-LOX strongly suggests a re-consideration of phenidone and its analogs as 5-LOX inhibitors in humans.

New triterpene glycosides from the stems of Anomospermum grandifolium.

Two new dammarane saponins identified as jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[beta-d-glucopyranosyl(1-->6) beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (2) and jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[6-O-[3-hydroxy-3-methylglutaryl]-beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (3) and a new lupane saponin, 3beta-hydroxylup-20(29)-en-27,28-dioic acid 28-O-beta-d-glucopyranosyl(1-->2)-[beta-d-xylopyranosyl(1-->3)]-beta-d-xylopyranosyl(1-->2)-beta-d-glucopyranoside ester (5), along with the known jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (1) and 3beta-hydroxylup-20(29)-ene-27,28-dioic acid (4), were isolated from the methanol extract of the stems of Anomospermum grandifolium. The structures of the new compounds were established by spectral analysis. Antimicrobial activity screening of compounds 1-3 revealed antifungal properties against C. albicans ATCC 3153 for compounds 2 and 3. The antibacterial and antifungal activities of the petroleum ether, chloroform, and methanol extracts of A. grandifolium stems were also evaluated.

Anti-inflammatory sesquiterpene lactones from Lourteigia ballotaefolia.

Three sesquiterpene lactones were isolated from Lourteigia ballotaefolia (H. B. K.). 9beta-hydroxy-atripliciolide-8- O-tiglate ( 1) was isolated for the first time from this plant and was previously reported in Conocliniopsis prasiifolia (DC) K. et R., 9beta-hydroxy-atripliciolide-8- O-(5'-acetoxytiglate) ( 2) had been already reported in this species. The minor component, 9beta-(tigloyloxy)-atripliciolide, is a new compound. The anti-inflammatory activity of compounds 1 and 2 was evaluated using the croton oil ear test in mice.

Screening of the topical anti-inflammatory activity of some Central American plants.

Hexane, chloroform and methanol extracts of seven herbal drugs used in the folk medicine of Central America against skin disorders (Aristolochia trilobata leaves and bark, Bursera simaruba bark, Hamelia patens leaves, Piper amalago leaves, and Syngonium podophyllum leaves and bark) were evaluated for their topical anti-inflammatory activity against the Croton oil-induced ear oedema in mice. Most of the extracts induced a dose-dependent oedema reduction. The chloroform extract of almost all the drugs exhibited interesting activities with ID(50) values ranging between 108 and 498 micro g/cm(2), comparable to that of indomethacin (93 micro g/cm(2)). Therefore, the tested plants are promising sources of principles with high anti-inflammatory activity.