In vitro cytotoxic activity of abietane diterpenes from Peltodon longipes as well as Salvia miltiorrhiza and Salvia sahendica.

Phytochemical investigations of the n-hexane extract from the roots of Peltodon longipes (Lamiaceae) resulted in the isolation of 12 known abietane diterpenes (1-12). Structures were established on the basis of one and two dimensional nuclear magnetic resonance spectroscopic data ((1)H and (13)C, COSY, HSQC and HMBC), electron ionization mass spectrometric analysis (EIMS) as well as comparison with data from literature. These compounds, as well as eight known diterpenes (13-19) from Salvia miltiorrhiza, and two from Salvia sahendica (20 and 21) were evaluated for their cytotoxic effects in human pancreatic (MIAPaCa-2) and melanoma (MV-3) tumor cell lines using the MTT assay. Tanshinone IIa (13), 7α-acetoxyroyleanone (1), 1,2-dihydrotanshinone (16) and cryptotanshinone (14) had the highest cytotoxic effects in MIAPaCa-2, displaying IC(50) of 1.9, 4.7, 5.6, and 5.8 µM, respectively. Structure-activity relationships of abietane diterpenoid quinones are discussed.

Pharmacophore design of p38α MAP kinase inhibitors with either 2,4,5-trisubstituted or 1,2,4,5-tetrasubstituted imidazole scaffold.

Synthetic compounds with a tri- and tetra-substituted imidazole scaffold are known as selective inhibitors of the p38 mitogen-activated protein (MAP) kinase responsible for proinflammatory cytokine release. The scope is to review the literature describing their design, synthesis and activity studies. To date a great plethora of crystal structures of p38 in complex with small organic ligands have been published. Cocrystallized ligand information is of particular interest to our review study, i.e. ATP itself, the reference inhibitor SB203580 with its aryl-pyridinyl-imidazoles and related imidazole and pyrimidine-based derivatives. The selective inhibitors bind to the pocket of adenosine 5'-triphoshate (ATP) replacing the latter. The hydrophobic region II, however, is not occupied by the natural binder ATP, but accommodates the pyridine substituents preserving the 4-fluorophenyl ring occupation in pocket I as a prerequisite to gain higher binding selectivity and potency than the reference compound SB203580 (4-[5-(4-fluoro-phenyl)-2-(4-methanesulfinyl-phenyl)-3himidazol-4-yl]-pyridine). Experimental and computed work is reviewed which evidence that the 2 position of the pyrimidine ring is amenable to the introduction of a side chain and the replacement of pyridine in SB203580 by a pyrimidine ring improves both inhibitory activity and selectivity for p38 over other kinases. All ligands with a pyridyl C2 side chain occupy the hydrophobic pocket II and in some cases a double hydrogen bond is reported between methionine 109 and glycine 110 of the hinge region, following an observed backbone shift. The substituted pyridine ring binds stronger than the two other side chains on the imidazole scaffold.

Identification of rosmarinic acid as the major active constituent in Cordia americana.

ETHNOPHARMACOLOGICAL RELEVANCE: Preparation from leaves of Cordia americana have been widely used in traditional medicine in South Brazil to treat wounds and various inflammations. AIM OF THE STUDY: The objective of this work was to identify the effective compounds in the ethanolic extract prepared from the leaves of Cordia americana, which is used in traditional South Brazilian medicine as anti-inflammatory and wound healing remedy. MATERIALS AND METHODS: Isolation and structure elucidation techniques were performed in order to identify the compounds of Cordia americana and HPLC analysis was used for the quantification. The major constituent and the ethanolic extract were investigated for inhibition of 5-lipoxygenase, p38alpha MAPK, TNFalpha release and NF-kappaB as well as in the fibroblast scratch assay. RESULTS: Rosmarinic acid (1) was identified as the major compound with an amount of 8.44% in the ethanolic extract of the leaves of Cordia americana. The ethanolic extract as well as (1) exhibited the highest inhibitory effects on 5-lipoxygenase (IC(50)=0.69 and 0.97microg/mL, resp., IC50 of BWA4C as reference: 0.3microM) and p38alpha (IC50=3.25 and 1.16microg/mL, resp., IC50 of SB203580 as reference: 0.046microM) and moderate inhibitory effects on TNFalpha release. Slight effects were observed in the fibroblast scratch assay. CONCLUSIONS: This study increases our knowledge on the effective compound in Cordia americana and supports its use in traditional medicine. We demonstrated for the first time pharmacological effects of Cordia americana and we provide evidences for a crucial role of rosmarinic acid as the major key player.

Participation of leukotriene C(4) in the regulation of suicidal erythrocyte death.

Eryptosis, the suicidal death of erythrocytes, is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface. Eryptosis is triggered by increase in cytosolic Ca(2+) concentration upon energy depletion. The present study explored the involvement of leukotrienes. Western blotting was employed to detect the cysteinyl-leukotriene receptor cysLT1, competitive immune assay to determine leukotriene release from erythrocytes, Fluo3 fluorescence to estimate cytosolic Ca(2+) concentration, forward scatter to analyse cell volume and annexin V-binding to disclose phosphatidylserine exposure. As a result, erythrocytes expressed the leukotriene receptor CysLT1. Glucose depletion (24 hours) significantly increased the formation of the cysteinyl-leukotrienes C(4)/D(4)/E(4). Leukotriene C(4) (10 nM) increased Ca(2+) entry, decreased forward scatter, activated caspases 3 and 8, and stimulated annexin V-binding. Glucose depletion similarly increased annexin V-binding, an effect significantly blunted in the presence of the leukotriene receptor antagonist cinalukast (1 microM) or the 5-lipoxygenase inhibitor BW B70C (1 microM). In conclusion, upon energy depletion erythrocytes form leukotrienes, which in turn activate cation channels, leading to Ca(2+) entry, cell shrinkage and cell membrane scrambling. Cysteinyl-leukotrienes thus participate in the signaling of eryptosis during energy depletion.

Biological studies on Brazilian plants used in wound healing.

AIM OF THE STUDY: n-Hexanic and ethanolic extracts from twelve plants (Brugmansia suaveolens Brecht. et Presl., Eupatorium laevigatum Lam., Galinsoga parviflora Cav., Iresine herbstii Hook., Kalanchöe tubiflora Hamet-Ahti, Petiveria alliacea L., Pluchea sagittalis (Lam.) Cabrera, Piper regnellii DC., Schinus molle L., Sedum dendroideum Moç et Sessé ex DC., Waltheria douradinha St. Hill., Xanthium cavanillesii Schouw.) used in traditional South Brazilian medicine as wound healing agents were investigated in various biological assays, targeting different aspects in this complex process. MATERIALS AND METHODS: The extracts were investigated on NF-kappaB DNA binding, p38alpha MAPK, TNF-alpha release, direct elastase inhibition and its release as well as on caspase-3. Fibroblasts migration to and proliferation into the wounded monolayers were evaluated in the scratch assay, the agar diffusion test for antibacterial and the MTT assay for cytotoxic effects. RESULTS: The hydrophilic extracts from Galinsoga parviflora, Petiveria alliacea, Schinus molle, Waltheria douradinha and Xanthium cavanillesii as well as the lipophilic extract of Waltheria douradinha turned out to be the most active ones. CONCLUSIONS: These results increase our knowledge on the wound healing effects of the investigated medicinal plants. Further studies are necessary to find out the effective secondary metabolites responsible for the observed effects.

The dual inhibitor of lipoxygenase and cyclooxygenase ML3000 decreases the expression of CXCR3 ligands.

OBJECTIVE: To find previously unknown properties of ML3000, a competitive inhibitor of the cyclooxygenase and the lipoxygenase (LO) pathway. METHODS: Gene expression of ML3000 treated and untreated rheumatoid arthritis synovial fibroblasts were measured with Affymetrix gene arrays. Downregulation of chemokine (C-X-C motif) ligands CXCL9, CXCL10 and CXCL11 was verified with Real-time polymerase chain reaction, CXCL10 protein levels were determined with ELISA. Rheumatoid arthritis synovial fibroblasts were treated with the cyclooxygenase inhibitor naproxen, the 5-LO inhibitor BWA4C and the 5-lipoxygenase-activating protein (FLAP) inhibitor MK886, and consecutive changes in CXCL10 protein levels measured. 5-LO expression was determined by polymerase chain reaction and Western blot. RESULTS: In synovial fibroblasts and monocyte-derived macrophages ML3000 inhibited the tumour necrosis factor induced expression of CXCL9, CXCL10 and CXCL11, which are all ligands of the chemokine receptor CXCR3. No effect was observed in monocytes. Whereas inhibition of the cyclooxygenase pathway or the FLAP protein showed no effect, blockade of 5-LO significantly downregulated CXCL10 protein levels. 5-LO mRNA was detected in monocytes and in monocyte-derived macrophages. All tested cell types expressed 5-LO protein. CONCLUSIONS: ML3000 effectively downregulates CXCR3 ligands. This study confirms that a thorough analysis of the impact of a drug on its target cells cannot only reveal unexpected properties of a substance, but also helps to understand the underlying molecular mechanisms. Accordingly, our data provide the basis for further clinical studies testing the application of ML3000 in diseases such as rheumatoid arthritis or multiple sclerosis.

Treatment with licofelone prevents abnormal subchondral bone cell metabolism in experimental dog osteoarthritis.

OBJECTIVES: To determine if treatment with licofelone, a combined 5-lipoxygenase and cyclo-oxygenase inhibitor, in vivo in experimental dog osteoarthritis can modify bone cell metabolism in long term in vitro subchondral osteoblast cell cultures (Ob). METHODS: Group 1 received sectioning of the anterior cruciate ligament (ACL) of the right knee with no active treatment (placebo group). Groups 2 and 3 received sectioning of the ACL of the right knee, and were given licofelone (2.5 or 5.0 mg/kg daily by mouth, respectively) for eight weeks beginning the day after surgery. Primary Ob were prepared from the subchondral bone plate. Levels of phenotypic markers (alkaline phosphatase activity, osteocalcin release), and urokinase plasminogen activator (uPA) and insulin-like growth factor-1 (IGF-I) levels, were evaluated in each group. Lastly, prostaglandin E(2) (PGE(2)) and leucotriene B(4) levels were evaluated. RESULTS: No significant differences in alkaline phosphatase activity or osteocalcin release from Ob between the three groups, under either basal or 1,25(OH)(2)D(3) induction were seen. In contrast, treatment with licofelone reduced uPA and IGF-I levels in Ob. PGE(2) levels, which were still raised in the placebo group, were decreased sharply by licofelone. A relationship was found between licofelone treatment and either the reduction in the size of lesions on tibial plateaus or the levels of uPA, IGF-I, or PGE(2). CONCLUSIONS: Licofelone treatment prevents and/or delays the abnormal metabolism of subchondral osteoblasts in this model. Licofelone reduced PGE(2) levels after long term Ob, suggesting that the reduction in uPA and IGF-I levels is linked, at least in part, to this reduction.

An in-vitro screening assay for the detection of inhibitors of proinflammatory cytokine synthesis: a useful tool for the development of new antiarthritic and disease modifying drugs.

OBJECTIVE: This work targets the development of a new tool to help develop new anticytokine drugs that prevent or reduce the progression of arthritic diseases. The specific aim of our study was to establish a fast and reliable in vitro screening assay of cytokine synthesis inhibitors (TNFalpha, IL-1beta) which shows better correlation with enzyme assays than previously reported in vitro assays. The test system should be able to detect p38-MAP kinase inhibitors. MATERIAL AND METHODS: Human peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll density gradient centrifugation from human EDTA-potassium whole blood. Cells were adjusted at 1 x 10(6) cells/ml. PBMCs were stimulated with lipopolysaccharide (LPS; E. coli serotype 026:B6: 1 microg/ml) in the presence of test compound (10(-5)-10(-8)M) for 4h at 37 degrees C in a 5% CO(2)-incubator. Induced TNFalpha and IL-1beta protein were measured by ELISA. RESULTS: The following are representative examples of inhibitors which effect cytokine synthesis. Corticoid Dexamethasone inhibits IL-1beta and TNFalpha synthesis at IC(50) of 38 nM and 25 nM, respectively. ERK1/ERK2 inhibitor U0126 effects cytokine synthesis at IC(50) of 0.34 microM for IL-1beta production and 0.26 microM for TNFalpha synthesis.p38-MAP kinase inhibitor SB 203580 inhibits IL-1beta- and TNF-alpha-synthesis (IC(50)sof 0.052 microM and 0.46 microM) in the same degree as p38-MAP kinase activity (IC(50): 0.34 microM). Same results could be shown for SB 210313, which had same efficacy on IL-1beta and TNFalpha biosynthesis (IC(50)'s: 1.88 microM and 1.01 microM) and on p38-MAP kinase (IC(50): 6.85 microM). Also for SB 202190 this correlation in inhibition of IL-1beta and TNFalpha synthesis (IC(50)'s: 0.055 microM and 1.01 microM) and p38-MAP kinase inhibition (IC(50): 0.088 microM) could be shown. CONCLUSION: This study shows the screening assay using PBMCs stimulated with LPS for IL-1beta and TNFalpha synthesis is a reliable test system for the quantification of the effectiveness of new drugs modulating IL-1beta and TNFalpha synthesis which is mainly mediated by p38-MAP Kinase. These assay allows fast detection of IL-1beta and TNFalpha synthesis inhibitors with different modes of action, including p38-MAP kinase inhibitors. The results obtained with our in-vitro screening assay show good correlation with results from enzyme assays.

The mechanism of action of the new antiinflammatory compound ML3000: inhibition of 5-LOX and COX-1/2.

OBJECTIVE: We examined the effects of ML3000 and several non-steroidal antiinflammatory drugs (NSAIDs) on the synthesis of products of 5-LOX (LTB4, LTC4) and COX-1/2 (TXB2, PGE2) in vitro and ex vivo in order to further elucidate the mechanism of action of ML3000. METHODS AND RESULTS: Using a human whole blood assay the effect of ML3000 on the shunt of arachidonic acid to the lipoxygenase pathway when COX is blocked was studied. ML3000 (0.3, 1, 3, 10, 30 microg/ml) and indomethacin (0.3, 1, 3, 10, 30 microg/ml) concentration-dependently inhibited the synthesis of PGE2 (IC50 = 3.9 and 4.5 microM). In contrast to ML3000, indomethacin produced an increase of LTC4 of up to 155.5% of control. 5-lipoxygenase inhibition was further tested in a basophilic leukemia cell assay using RBL-1 cells. ML3000 (1-10 microM) inhibited the synthesis of LTB4 in a concentration related manner (IC50: 3.6 microM). In carrageenan induced rat paw edema, ML3000 and indomethacin completely blocked the formation of PGE2 in the inflamed tissue. The LTB4 production in the inflamed paw was reduced to basal levels by ML3000 (10 +/- 1.4 pg/paw saline control and 7.5 +/- 1.3-5.9 +/- 3.2 pg/paw ML3000), whereas LTB4 levels remained markedly elevated as compared to saline control by indomethacin (30.7 pg/paw). 5-LOX inhibition in the inflamed rat colon was investigated by measuring LTB4 synthesis. MK-886 and ML3000 at 10 mg/kg p.o. reduced LTB4 production to 29.8 +/- 4.9 and 30.1 +/- 2.8 pg/mg tissue as compared to control (54.2 +/- 7.4 mg/kg tissue). LTB4 levels in the rat stomach were comparable to control (2.5 +/- 0.4 pg/mg protein) after oral administration of ML3000 (10, 30, 100 mg/kg), whereas oral treatment with indomethacin (0.3, 1, 3 mg/kg) or diclofenac (1, 3 mg/kg) increased LTB4 up to 9.2 +/- 2.3 or 8.9 +/- 1.6 pg/mg protein. This effect was significant at 1 mg/kg diclofenac and 0.3 mg/kg indomethacin. CONCLUSIONS: These results provide further evidence, that ML3000 inhibits 5-LOX as well as COX-1 and COX-2 in vitro and in animal experiments. The favourable gastrointestinal (GI) tolerability of the compound is believed to be linked to the mechanism of combined 5-LOX and COX-1/2 inhibition of ML3000.

In vivo dual inhibition of cyclooxygenase and lipoxygenase by ML-3000 reduces the progression of experimental osteoarthritis: suppression of collagenase 1 and interleukin-1beta synthesis.

OBJECTIVE: To study the therapeutic effectiveness of ML-3000, a new antiinflammatory drug that has balanced dual inhibitory activity against 5-lipoxygenase and cyclooxygenase, on the development of lesions in the experimental osteoarthritis (OA) dog model, and to determine the action of ML-3000 on the synthesis of collagenase 1 in cartilage and interleukin-1beta (IL-1beta) in synovial membrane. METHODS: The anterior cruciate ligament of the right stifle joint of 21 mongrel dogs was sectioned with a stab wound. Dogs were divided into 3 groups: group 1 (n = 7) received placebo; groups 2 (n = 7) and 3 (n = 7) were treated with therapeutic dosages of oral ML-3000 at 2.5 mg/kg/day and 5 mg/kg/day, respectively. The dogs began receiving medication the day after surgery and were killed 8 weeks later. The size and grade of cartilage erosions on both the condyles and plateaus were evaluated, and the severity of the cartilage lesions and synovial inflammation was examined histologically. Levels of collagenase 1 in cartilage and IL-1beta in the synovial membrane were measured by immunohistochemistry. In addition, levels of prostaglandin E2 (PGE2) in the synovial fluid and leukotriene B4 (LTB4) in cultured synovial membrane explants were determined using specific enzyme immunoassays. RESULTS: Serum levels of ML-3000 in treated dogs were within the therapeutic range. ML-3000 significantly decreased the size and grade of the cartilage lesions in tibials and plateaus, compared with placebo. At the histologic level, the severity of cartilage lesions was also decreased in the ML-3000-treated dogs versus the placebo-treated dogs in both the condyles and the plateaus. All 3 OA groups exhibited a notable and similar level of synovial inflammation. ML-3000 significantly decreased the level of PGE2 in synovial fluid and LTB4 production by synovium. It also markedly reduced the levels of collagenase 1 in cartilage and IL-1beta in synovial membrane. CONCLUSION: ML-3000 significantly reduced the development of lesions in experimental dog OA. The drug acts by reducing the synthesis of the inflammation mediators PGE2 and LTB4 and catabolic factors such as collagenase 1 and IL-1beta, which are known to play an important role in the pathophysiology of OA lesions. The effect of the drug on catabolic factors could possibly be related to its inhibitory action on LTB4 synthesis.

Anti-inflammatory activity of myricetin-3-O-beta-D-glucuronide and related compounds.

OBJECTIVE AND DESIGN: The anti-inflammatory effect of myricetinglucuronide (MGL) was investigated and structurally-related compounds were compared to examine the structure/activity-relationship in carrageenan-induced rat paw edema. MATERIALS AND SUBJECTS: In vitro studies were performed using rat basophilic leukemia (RBL-1) cells, human polymorphonuclear leukocytes (PMNL), COX-1 from ram seminal vesicle, COX-2 from sheep placenta and human venous blood. For the in vivo tests male Wistar rats were used, for the ex vivo test perfused rabbit ears. TREATMENT: 1-300 microg/kg MGL or myricetinmethylglucuronate and 0.1-5 mg/kg other related compounds administered p.o. (carrageenan edema). 5, 50 and 150 microg/kg MGL p.o. for 14 days (Freund's adjuvant arthritis), 5 and 50 microg/kg p.o. for 6 days (ulceration). METHODS: Anti-inflammatory effects were measured in carrageenan edema and in adjuvant arthritis. Incidence of gastric lesions was tested in an ulcerogenicity model in vivo. Influence on COX was determined in the perfused rabbit ear, in PMNL and in a test assay using COX-1 and COX-2. 5-LOX activity was studied using PMNL and RBL-1. The influence on platelet aggregation was evaluated measuring light transmission. RESULTS: MGL exerted a marked and dose-dependent anti-inflammatory effect in acute (carrageenan edema, ED50 15 microg/kg, indomethacin ED50 10 mg/kg) and chronic (adjuvant arthritis, inhibition at 150 microg/kg 18.1 % left paw, 20.6% right paw, indomethacin 3 mg/kg 18.0% and 19.4%)) models of inflammation. In the perfused rabbit ear 1 microg MGL inhibited the release of PGI2, PGD2 and PGE2 to the same extent as 1 microg indomethacin. The inhibition of COX-1 in the intact cell system was IC50 = 0.5 microM, that of indomethacin 0.0038 microM. In the isolated enzyme preparations of COX-1 and COX-2 the IC50 was 10 microM and 8 microM, that of indomethacin 9.2 mM and 2.4 microM. In the RBL-1 and PMNL test assay the inhibition of 5-LOX was 0.1 microM and 2.2 microM. An orally administered dose of 50 microg/kg/day induced no gastric ulcers in rats treated for 6 days. The investigations on carrageenan edema showed a close relationship between the structure of MGL and the anti-inflammatory effect. CONCLUSIONS: MGL is a COX-1, COX-2 and 5-LOX inhibitor. In view of the moderate in vitro activity and the very potent in vivo activity an additive mechanism must be involved. Small changes in the molecular structure lead to the loss or reduction of the anti-inflammatory activity.

Studies on the in vitro and in vivo genotoxicity of [2,2-dimethyl-6- (4-chlorophenyl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-yl]-acetic acid.

[2,2-Dimethyl-6-(4-chlorophenyl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5- yl]-acetic acid (CAS 156897-06-2, ML 3000) was examined for genotoxic activity in bacteria and mammalian cells in vitro as well as in vivo. The substance did not increase gene mutation frequencies either in a bacterial system or in a cultured V79 cell line of the Chinese hamster. Both in vitro tests were conducted in the presence and absence of S9-mix. In the unscheduled DNA synthesis assay in vitro with primary rat hepatocytes, negative results were also obtained. A cytogenetic analysis of the bone marrow of male and female Wistar rats was performed. After oral application ML 3000 did not increase the number of cells with structural chromosomal aberrations. The results suggest that ML 3000 has no genotoxic potential in vitro and in vivo.

Induced moderate hypotensive anesthesia for spinal fusion and Harrington-rod instrumentation.

The effect of moderate hypotensive anesthesia on blood loss, need for transfusion, and length of surgery of forty-nine patients who underwent posterior spinal fusion and Harrington-rod instrumentation was compared retrospectively. Twenty-seven patients were given enflurane as the main anesthetic agent, with fentanyl supplementation, and their blood pressure was maintained at twenty to thirty millimeters of mercury less than the preoperative systolic blood pressure. These patients were compared with twenty-two patients who had been anesthetized with nitrous oxide, oxygen, and narcotic technique and were normotensive throughout the duration of the anesthesia. The results were analyzed by the unpaired Student t test. Moderate hypotensive anesthesia was found to significantly decrease the average blood loss by nearly 40 per cent, reduce the need for transfusion by nearly 45 per cent, and shorten the average operating time by nearly 10 per cent. No complications attributable to the anesthetic technique occurred. The findings of this study suggest that moderate hypotensive anesthesia with enflurane and fentanyl supplementation may be of benefit in scoliosis surgery by reducing blood loss, the need for blood replacement, and operating time.