lignans and Pleurisy

Sesame oil is widely consumed as nutritious food, cooking oil, and in pharmaceuticals and food. In this study, the antinociceptive and anti-inflammatory properties of the sesame oil and sesamin were investigated. The sesame oil and sesamin reduced the number of abdominal contortions at the doses 100, 200, or 400 mg/kg. The first and second phases of the time paw licking were inhibited by sesame oil and sesamin (100, 200, or 400 mg/kg). After 90 min of treatment, sesame oil and sesamin increased the reaction time on a hot plate (200 or 400 mg/kg). Considering the tail-immersion assay, the sesame oil and sesamin produced significant effect after 60 min at the doses of 100, 200, or 400 mg/kg. After 4 h of application of the carrageenan, the sesame oil and sesamin were effective against the paw edema. The exudate volume and leucocyte migration were also reduced by sesame oil and sesamin. These results suggest that sesamin is one of the active compounds found in sesame oil and justify the antinociceptive and anti-inflammatory properties of this product.

Topics: Acetic Acid; Analgesics; Animals; Anti-Inflammatory Agents; Carrageenan; Dioxoles; Edema; Formaldehyde; Inflammation; Lignans; Male; Mice; Nociception; Pain; Pleurisy; Rats; Rats, Wistar; Sesame Oil; Toxicity Tests, Acute

Previous studies have shown that the extracts obtained from Phyllanthus amarus, and some of the lignans isolated from it, exhibit pronounced antiinflammatory properties. In the present study, we have assessed whether the antiinflammatory actions of these lignans can be mediated by interaction with platelet activating factor (PAF) receptor or interference with the action of this lipid. The local administration of nirtetralin, phyltetralin or niranthin (30 nmol/paw), similar to WEB2170 (a PAF receptor antagonist, 30 nmol/paw), significantly inhibited PAF-induced paw oedema formation in mice. The extracts of P. amarus (100 microg/ml) and niranthin (30 microM), but not nirtetralin or phyltetralin (30 microM), decreased the specific binding of [(3)H]-PAF in mouse cerebral cortex membranes. Furthermore, both niranthin and WEB2170 displaced, in a concentration-dependent manner, the [(3)H]-PAF binding sites. The mean IC(50) values from these effects were 6.5 microM and 0.3 microM, respectively. Additionally, both niranthin and WEB2170 (30 nmol/paw) inhibited the increase of myeloperoxidase activity induced by PAF injection in the mouse paw. When assessed the mouse model of pleurisy induced by PAF, pretreatment with niranthin (100 micromol/kg, p.o.) or WEB2170 (1.7 micromol/kg, i.p.) significantly inhibited PAF-induced protein extravasations. Moreover, in the rat model of PAF-induced allodynia, both niranthin (30 nmol/paw) and WEB2170 (30 nmol/paw) treatment significantly inhibited PAF-induced allodynia. In addition, niranthin had a rapid onset and long-lasting antiallodynic action when compared with WEB2170. Collectively, the present findings suggest that niranthin exhibits antiinflammatory and antiallodynic actions which are probably mediated through its direct antagonistic action on the PAF receptor binding sites.

Topics: Analgesics; Animals; Anisoles; Anti-Inflammatory Agents; Azepines; Binding, Competitive; Carrageenan; Cerebral Cortex; Dioxoles; Inflammation; Lignans; Male; Mice; Pain Measurement; Pain Threshold; Peroxidase; Phyllanthus; Plant Extracts; Platelet Activating Factor; Platelet Aggregation Inhibitors; Platelet Membrane Glycoproteins; Pleurisy; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Tetrahydronaphthalenes; Time Factors; Triazoles

In this study we examined the ability of the furofuran lignan yangambin to influence the local and systemic responses induced by antigen or PAF in actively sensitized or normal rats. Given intraperitoneally 1 h before stimulation, yangambin inhibited the pleural neutrophil and eosinophil infiltration evoked by the i.pl. injection of PAF or antigen into normal or 14 daysensitized rats whereas plasma exudation evoked by both stimuli was unaffected. The pleural neutrophil influx (6 h) after LTB4 stimulation was also significantly inhibited by yangambin. We also evidenced that the hemoconcentration, thrombocytopenia, and leucocytosis noted after i.v. PAF were all attenuated by yangambin. In actively sensitized rats, pretreatment with yangambin failed to modify the antigen-induced hemoconcentration and leucocytosis, but dose-dependently abrogated the thrombocytopenia noted 1 h post-stimulation. In vitro, the anaphylactic contraction of longitudinal jejunal segments to antigen challenge was significantly inhibited by yangambin (10(-5)-10(-4) M). Likewise, the contraction of jejunal segments from normal rats to PAF was markedly blocked by yangambin under conditions where the response to 5-hydroxytryptamine (5-HT) was not altered. In conclusion, our results show that antigen- and PAF-induced pleural neutrophil and eosinophil accumulation, but not exudation, is sensitive to treatment with yangambin. In addition, yangambin also suppressed the pleural neutrophil infiltration triggered by LTB4 as well as the blood thrombocytopenia and intestinal anaphylaxis elicited by antigen in rats. Thus, our findings indicate that yangambin shows an antagonistic action on receptors other than those of PAF, i.e., LTB4, and strongly suggest that it may be a useful drug in the treatment of some allergic inflammatory responses.

Topics: Animals; Anti-Allergic Agents; Eosinophils; Female; Furans; Leukocytosis; Lignans; Male; Neutrophils; Plant Extracts; Platelet Activating Factor; Pleurisy; Rats; Rats, Wistar; Thrombocytopenia

In the present study, A23187-induced pleurisy in mice was used to investigate the anti-inflammatory effect of magnolol, a phenolic compound isolated from Chinese medicine Hou p'u (cortex of Magnolia officinalis). A23187-induced protein leakage was reduced by magnolol (10 mg kg-1, i.p.), indomethacin (10 mg kg-1, i.p.) and BW755C (30 mg kg-1, i.p.). A23187-induced polymorphonuclear (PMN) leucocyte infiltration in the pleural cavity was suppressed by magnolol and BW755C, while enhanced by indomethacin. Like BW755C, magnolol reduced both prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels in the pleural fluid of A23187-induced pleurisy, while indomethacin reduced PGE2 but increased LTB4 formation. In the rat isolated peripheral neutrophil suspension, magnolol (3.7 microM) and BW755C (10 microM) also suppressed the A23187-induced thromboxane B2 (TXB2) and LTB4 formation. These results suggest that magnolol, like BW755C, might be a dual cyclo-oxygenase and lipoxygenase inhibitor. The inhibitory effect of magnolol on the A23187-induced pleurisy is proposed to be, at least partly, dependent on the reduction of the formation of eicosanoids mediators in the inflammatory site.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Biphenyl Compounds; Body Fluids; Calcimycin; Dinoprostone; Disease Models, Animal; Leukotriene B4; Lignans; Mice; Mice, Inbred ICR; Plant Extracts; Pleura; Pleurisy; Proteins; Rats; Rats, Sprague-Dawley