stigmasterol and Peritonitis

Stigmasterol is a phytosterol that presents pharmacologic properties. However, its anti-inflammatory mechanism and antinociceptive effect are not yet elucidated. Thus, the present study aimed to investigate the anti-inflammatory and antinociceptive activities of stigmasterol and its mechanism of action in mice. The antinociceptive activity was assessed by the acetic acid-induced writhing test, formalin test, and hot plate test. The anti-inflammatory activity was investigated by carrageenan-induced peritonitis and paw edema induced by arachidonic acid. The involvement of glucocorticoid receptors in the mechanism of stigmasterol anti-inflammatory action was investigated by molecular docking, also by pretreating mice with RU-486 (glucocorticoid receptor antagonist) in the acetic acid-induced writhing test. Mice motor coordination was evaluated by the rota-rod test and the locomotor activity by the open field test. The lowest effective dose of stigmasterol was standardized at 10 mg/kg (p.o.). It prevented abdominal writhes and paw licking, but it did not increase the latency time in the hot plate test, suggesting that stigmasterol does not show an antinociceptive effect in response to a thermal stimulus. Stigmasterol decreased leukocyte infiltration in peritonitis assay and reduced paw edema elicited by arachidonic acid. Molecular docking suggested that stigmasterol interacts with the glucocorticoid receptor. Also, RU-486 prevented the effect of stigmasterol in the acetic-acid abdominal writhing test, which might indicate the contribution of glucocorticoid receptors in the mechanism of stigmasterol action. Stigmasterol reduced the number of crossings but did not impair mice's motor coordination. Our results show that stigmasterol presents anti-inflammatory effects probably mediated by glucocorticoid receptors.

Topics: Analgesics; Animals; Anti-Inflammatory Agents; Disease Models, Animal; Dose-Response Relationship, Drug; Edema; Inflammation; Male; Mice; Mifepristone; Molecular Docking Simulation; Pain; Peritonitis; Receptors, Glucocorticoid; Stigmasterol

Polygala sabulosa A. W. Bennett is a small herb popularly known as "timutu-pinheirinho" that is widely distributed in southern Brazil and that is used to treat disorders of the bowel and kidney and as a topical anesthetic and expectorant in folk medicine. This study was designed to investigate the anti-inflammatory properties of the hydroalcoholic extract (HEPs), CH2Cl2 fraction and the steroid α-spinasterol obtained from the aerial parts of Polygala sabulosa in a model of acute inflammation induced by intraperitoneal injection of bacterial lipopolysaccharide in mice.. The anti-inflammatory effect of HEPs (3-300 mg/kg, i.g.), CH2Cl2 fraction (0.003-30 mg/kg, i.g.) and steroid α-spinasterol (0.001-1mg/kg, i.p. or 1-10mg/kg, i.g.), were evaluated in mice subjected to the acute inflammation caused by intraperitoneal (i.p.) injection of lipopolysaccharide (LPS, 0.02 µg/kg). The anti-inflammatory activity of the HEPs, CH2Cl2 fraction and steroid were assessed by determining the total numbers of leukocytes and differential cell counts (neutrophils and mononuclear cells) and levels of pro-inflammatory (IL-1β, TNF-α, IL-6) or anti-inflammatory (IL-10) cytokines in peritoneal fluid.. The administration of HEPs (3-300 mg/kg, i.g.) completely inhibited inflammatory cell infiltration (300 mg/kg, i.g.) and it reduced TNF-α (100-300 mg/kg) and IL-1β (100mg/kg) levels in LPS-injected mice. Furthermore, the administration of CH2Cl2 fraction (0.003-30 mg/kg, i.g.) or α-spinasterol (0.001-10mg/kg, by i.p. or i.g.) significantly reduces inflammatory cell infiltration in LPS-injected mice. Moreover, dexamethasone (0.5mg/kg, i.p., used as a positive control) inhibited inflammatory cell infiltration and reduced the levels of TNF-α, IL-1β and IL-6 in LPS-injected mice.. Taken together, these results provide the first experimental evidence demonstrating that HEPs have significant anti-inflammatory effects on LPS-induced inflammation. These effects appear to be, at least in part, due to the presence of α-spinasterol. These findings support the widespread use of Polygala sabulosa in popular medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with anti-inflammatory properties.

Topics: Animals; Anti-Inflammatory Agents; Ethanol; Lipopolysaccharides; Methylene Chloride; Mice; Molecular Structure; Peritonitis; Plant Extracts; Polygala; Stigmasterol; Water