In vivo anti-inflammatory and antinociceptive effects of liriodendrin isolated from the stem bark of Acanthopanax senticosus

In the present study, liriodendrin isolated by activity-guided fractionation from the ethyl acetate (EtOAc) extracts of the stem bark of Acanthopanax senticosus, was evaluated for anti-inflammatory and antinociceptive activities. Liriodendrin (5, 10 mg/kg/day, p. o.) significantly inhibited the increase of vascular permeability induced by acetic acid in mice and reduced an acute paw edema induced by carrageenan in rats. When the analgesic activity was measured by the acetic acid-induced writhing test and hot plate test, liriodendrin showed a dose-dependent inhibition in animal models. In addition, syringaresinol, the hydrolysate of liriodendrin, more potently inhibited the LPS-induced production of NO, PGE 2 and TNF-alpha production of macrophages than liriodendrin. Consistent with these observations, the expression level of iNOS and COX-2 enzyme was decreased by syringaresinol in a concentration-dependent manner. These results suggest that the anti-inflammatory and antinociceptive effects of liriodendrin after oral administration were attributable to the in vivo transformation to syringaresinol, which may function as the active constituent.     

Analgesic principle from the bark of Careya arborea

Bioactivity guided isolation of the bark of Careya arborea afforded piperine--an alkaloid chemically known as 1-[5-(1,3-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine, which was found to possess significant central and peripheral analgesic activity. At oral doses of 10, 20 and 30 mg/kg body weight, piperine exhibited 41 (p < 0.01), 45 (p < 0.01) and 53% (p < 0.001) inhibition of acetic acid induced writhing in mice respectively. At doses of 20 and 30 mg/kg body weight, the compound also showed 31.8 (p < 0.05) and 52.4% (p < 0.01) prolongation of tail flicking time of mice 30 min after the treatments determined by the radiant heat method.     

Isolation and identification of an anti-inflammatory principle from Capparis spinosa

The homologous polyprenols cappaprenol-12 (1), cappaprenol-13 (2) and cappaprenol-14 (3) with 12, 13 and 14 isoprene units, respectively, could be isolated by preparative HPLC from alcoholic extracts of Capparis spinosa. Testing 2 for its anti-inflammatory activity an inhibition of the carrageenan-induced paw edema in rats of 44 vs. 67% for the standard oxyphenbutazone was found.     

beta-Amyrin and alpha-amyrin acetate isolated from the stem bark of Alstonia boonei display profound anti-inflammatory activity

Context: Alstonia boonei De Wild (Apocyanaceae) is used in ethnomedicine for the management of malaria, ulcer, rhematic pain, toothache, and inflammatory disorders.

Objective: To investigate the anti-inflammatory potential of β-amyrin and α-amyrin acetate isolated from the stem bark of Alstonia boonei using animal models.

Materials and methods: Chromatographic purification of the crude methanol extract led to the isolation and structure elucidation of β-amyrin and α-amyrin acetate. Their anti-inflammatory activities were evaluated in rodents using egg albumen-induced paw edema and xylene-induced ear edema models. The gastric ulcerogenic, in vivo leucocyte migration, and RBC membrane stabilization tests were also investigated.

Results: α-Amyrin acetate at 100?mg/kg showed significant (p?p?>?0.01) irritation of the gastric mucosa while significant (p?p?p?Discussion and conclusion: This study generally provided evidence of profound anti-inflammatory activity of β-amyrin and α-amyrin acetate isolated from the Alstonia boonei stem bark.     

Analgesic and anti-inflammatory effects of the methanol stem bark extract of Prosopis africana

Prosopis africana (Guill. & Perr.) Taub. (Mimosoideae) is a shrub used for menstrual and general body pain in Nupe land in north central Nigeria. In this study, the methanol extract of the stem bark of Prosopis africana (at doses of 62.5, 125, and 250?mg/kg) was evaluated for analgesic and anti-inflammatory activities using acetic acid-induced writhing assay and carrageenan-induced inflammation in rats. The extract significantly (P <0.05) attenuated the acetic acid-induced writhing with the highest activity observed at the highest dose, 250?mg/kg (76.89%) comparable to that of piroxicam (83.16%) the standard agent used. In the carrageenan-induced inflammation assay, the extract showed significant anti-inflammatory activity (P <0.001) from the third hour. The preliminary phytochemical screening revealed the presence of flavonoids, saponins, carbohydrates, cardiac glycosides, tannins, and alkaloids. The oral median lethal dose was found to be 3807.9?mg/kg in mice and > 5000?mg/kg in rats. This study supports the folkloric claim of the use of Prosopis africana in the management of pain.     

Triterpenes involved in the anti-inflammatory effect of ethanolic extract of Pterodon emarginatus Vogel stem bark

Bioassay-guided fractionation of the ethanolic extract of Pterodon emarginatus Vogel stem bark (EtEx) resulted in the isolation and characterization of lupeol and betulin. Their structures were elucidated by spectroscopic methods including IR, ¹H-NMR, ¹³C-NMR and comparison with literature values. This study showed the anti-inflammatory activity of EtEx, the hexane (HexL) and dichloromethane (DichL) layers, and lupeol and betulin. The extract, HexL, DichL, lupeol and betulin were able to inhibit acetic acid-induced writhing. In the formalin test, EtEx decreased licking time only in the second phase characterizing anti-inflammatory activity. In the oil-induced ear oedema test, EtEx, lupeol and betulin decrease edema formation. In conclusion, EtEx has antinociceptive effects arising from anti-inflammatory activity; this activity could be due to the presence of lupeol and betulin.     

Anti-tuberculosis constituents from the stem bark of Micromelum hirsutum

Anti-TB bioassay-directed fractionation led to the isolation of six carbazole alkaloids, as well as the gamma-lactone derivative of oleic acid, from the CH (2)Cl (2) extract of the stem bark of Micromelum hirsutum. The carbazoles include the new micromeline ( 2) and five known alkaloids: lansine ( 3), 3-methylcarbazole ( 4), methyl carbazole-3-carboxylate ( 5), 3-formylcarbazole ( 6), and 3-formyl-6-methoxycarbazole ( 7). Compound 1 was identified as the lactone derivative of oleic acid, (-)- Z-9-octadecene-4-olide, for which the trivial name micromolide ( 1) is suggested. It showed potent in vitro anti-TB activity against H37R v (MIC: 1.5 microg/mL), a selectivity index (SI) of 63, and exhibited activity against the Erdman strain of M. tuberculosis in a J774 mouse macrophage model (EC (90) : 5.6 microg/mL). Thus, 1 appears worthy of further evaluation as a potential new anti-TB agent. Isolates 2, 3, 6 and 7 had anti-TB MIC values between 14.3 and 42.3 microg/mL, while compounds 4 and 5 were considered inactive (MIC > 128 microg/mL). Structure elucidation and identification were based on spectroscopic analysis, including MS, 1D/2D NMR, and a full (1)H spin system analysis of 1.     

Antioxidant compounds from the stem bark of Garcinia atroviridis

A new xanthone, namely garcinexanthone G (1), along with eight known compounds, stigmasta-5,22-dien-3β-ol (2), stigmasta-5,22-dien-3-O-β-glucopyranoside (3), 3β-acetoxy-11α,12α-epoxyoleanan-28,13β-olide (4), 2,6-dimethoxy-p-benzoquinone (5), 1,3,5-trihydroxy-2-methoxyxanthone (6), 1,3,7-trihydroxyxanthone (7), kaempferol (8) and quercetin (9), were isolated from the stem bark of Garcinia atroviridis. Their structures were elucidated based on spectroscopic methods including nuclear magnetic resonance (NMR-1D and 2D), UV, IR, and mass spectrometry. All the isolated compounds were evaluated for their antioxidant properties based on the DPPH radical scavenging activities. Results showed that 1,3,7-trihydroxyxanthone and quercetin showed significant antioxidant activities with EC₅₀ values of 16.20 and 12.68 μg/ml, respectively, as compared to the control, ascorbic acid (7.4 μg/ml).     

Antiplasmodial alkaloids from the stem bark of Strychnos malacoclados

From the stem bark of Strychnos malacoclados, one new bisindole alkaloid, 3-hydroxylongicaudatine Y (1), was isolated along with the known alkaloids vomicine (2), bisnordihydrotoxiferine (3), divarine (4), longicaudatine (5), longicaudatine Y (6), and longicaudatine F (7). All the compounds were tested for their antimalarial activity against the chloroquine-sensitive 3D7 and -resistant W2 strains of Plasmodium falciparum. Longicaudatine was the most active compound with IC?? values of 0.682 and 0.573 μM, respectively. The activity of compounds 1, 3, 4, 6, and 7 against the two strains ranged from 1.191 to 6.220 μM and 0.573 to 21.848 μM, respectively. Vomicine (2), the only monomer isolated, was inactive. The alkaloids of the longicaudatine-type ( 1, 5-7) were more active than those of the caracurine-type (3- 4). The presence of the ether bridge in the molecule seems to increase the antiplasmodial activity. Compounds 1, 5, and 7 were tested against the WI-38 human fibroblast cell line. Longicaudatine was the most cytotoxic compound with an IC?? of 2.721 μM. Longicaudatine F was 40-46 times more active against the two strains of P. falciparum than against the human fibroblasts and was thus considered as the more selective alkaloid. The structures of the compounds were determined based on the analysis of their spectral data.     

Bioactive triterpenoids from the stem bark of Picea glehni

Two new triterpenoids, 3 alpha-methoxyserrat-14-en-21 beta-yl formate (1), and 24-methylcycloartenone (2), were isolated from the stem bark of Picea glehni (Fr. Schm.) Masters together with three known triterpenoids, 3 alpha-methoxyserrat-14-en-21 beta-ol, 3 beta-methoxyserrat-14-en-21 beta-ol, and piceanonol A. Compounds 1, 2, and a synthetic sample, 3 alpha-methoxyserrat-13-en-21 beta-yl formate showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA).     

Cytotoxic triterpenes from stem bark of Physocarpus intermedius

Seven triterpenes (1-7), i.e., betulinic acid 1, ursolic acid 2, oleanolic acid 3, 3-O-caffeoyloleanolic acid 4, euscaphic acid 5, 2 alpha-hydroxyursolic acid 6 and maslinic acid 7 were isolated from the stem bark extract of P. intermedius as active principles responsible for the cytotoxicity against five cultured human tumor cell lines, i.e., A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCT-15 (colon), in vitro.     

Glucoindole alkaloids from stem bark of Strychnos mellodora

Three glucoindole alkaloids, dolichantoside (1), strictosidine (2), and palicoside (3), have been identified in the stem bark of Strychnos mellodora (Loganiaceae), collected in Zimbabwe. The chiroptical (CD) data are compared.     

2'-Hydroxycinnamaldehyde from stem bark of Cinnamomum cassia

2'-Hydroxycinnamaldehyde, which inhibits farnesyl-protein transferase (FPTase), has been isolated from the stem bark of Cinnamomum cassia Blume. The biologically active agent in the extract has been purified by silica column chromatography and HPLC. The structure of the isolated compound was elucidated on the basis of 500 MHz NMR experiments.     

Antinociceptive and anti-inflammatory effects of the ethyl acetate stem bark extract of Bridelia scleroneura (Euphorbiaceae)

Bridelia scleroneura is a member of the Euphorbiaceae family. In folk medicine in Cameroon, the stem bark of this plant is used for relieving abdominal pain, contortion, arthritis and inflammation. In this study, the antinociceptive and anti-inflammatory activities of the ethyl acetate stem bark extract have been evaluated. The putative analgesic effect of the plant extract was examined in abdominal constriction, hot plate, formalin and on pain using tail immersion mouse models and in carrageenan-induced paw edema in rats. The extract (150–600 mg/kg) exhibited a dose-dependent analgesic effect (46.27–78.97%) in acetic acid-induced abdominal constriction in mice. B. scleroneura extract increased the pain latency of nociceptive response to thermal stimuli at the higher dose of 600 mg/kg. B. scleroneuna induced significant dose-dependent reduction of the nociception in both early and late phases of the formalin test. The extract at the dose of 300 mg/kg, increased significantly, by 63.70% and 52.01% the tail-immersion latency time, 1 and 2 h post-dosing. In the carrageenan test, B. scleroneura (150–600 mg/kg, p.o) had dose-dependent and significant effects at different time intervals. This behaviour was similar to indometacin (10 mg/kg) used as a standard drug. These results show that the ethyl acetate stem bark extract of B. scleroneura possesses peripheral and central analgesic properties as well as anti-inflammatory activity against acute inflammation processes, in support of the folk medicinal use of the plant.     

A new furanoxanthone from the stem bark of Calophyllum inophyllum

The stem bark extracts of Calophyllum inophyllum furnished one new furanoxanthone, inophinnin (1), in addition to inophyllin A (2), macluraxanthone (3), pyranojacareubin (4), 4-hydroxyxanthone, friedelin, stigmasterol, and betulinic acid. The structures of these compounds were determined by spectroscopic analysis of 1D and 2D NMR spectral data ((1)H, (13)C, DEPT, COSY, HMQC, and HMBC) while EI-MS gave the molecular mass. The new xanthone, inophinnin (1), exhibited some anti-inflammatory activity in nitric oxide assay.