Coadministration of Stigmasterol and Dexamethasone (STIG+DEX) Modulates Steroid-Resistant Asthma.

Airway inflammation in asthma is managed with anti-inflammatory steroids such as dexamethasone (DEX). However, about 20% of asthmatics do not respond to this therapy and are classified as steroid-resistant. Currently, no effective therapy is available for steroid-resistant asthma. This work therefore evaluated the effect of a plant sterol, stigmasterol (STIG), and stigmasterol-dexamethasone combination (STIG+DEX) in LPS-ovalbumin-induced steroid-resistant asthma in Guinea pigs. To do this, the effect of drugs on inflammatory features such as airway hyperreactivity and histopathology of lung tissue was evaluated. Additionally, the possible pathway of drug action was assessed by measuring events such neutrophil levels, oxidative and nitrative stress, and histone deacetylase 2 (HDAC2) and interleukin 17 (IL-17) levels. STIG alone did not affect inflammatory features, although it caused some changes in the molecular events associated with steroid-resistant asthma. However, STIG+DEX caused significant modulation of inflammatory features by protecting against destruction of lung tissue. The modulation of inflammatory features was associated with significant inhibition of neutrophilia and oxidative and nitrative stress, decrease in HDAC2, and increase in IL-17 levels that are usually associated with steroid-resistant asthma. Our findings show that although STIG and DEX individually do not protect against steroid-resistant asthma, their coadministration results in significant modulation of inflammatory features and the associated molecular events that lead to steroid-resistant asthma.

Xylopic Acid Suppresses Adjuvant-induced Arthritis in Sprague Dawley Rats via Reduction in Serum Levels of IL-6 and TNF-alpha.

BACKGROUND: Xylopic acid (XA) is the principal constituent obtained from the biofractionation of the dried fruits of Xylopia aethiopica. Our initial reports have established the acute anti-inflammatory activity of this kaurene diterpene. OBJECTIVE: Currently, we investigate the chronic anti-inflammatory activity of xylopic acid. METHODS: The adjuvant-induced arthritis model in rats was employed in carrying out the study. RESULTS: It was observed from the study that XA significantly (P < 0.05) suppressed the oedema associated with adjuvant arthritis while preventing associated joint deformation as identified from the radiographs. Histopathological analysis of joints of treated animals revealed signs of bone reformation and re-calcification following XA administration. From the haematological analysis, xylopic acid significantly decreased eosinophil sedimentation rate (ESR) while also decreasing white blood cells (WBC), which were increased after arthritis induction. Serum analysis showed the inhibitory effect of XA on serum expression of IL-6 and TNF-alpha in arthritic rats. CONCLUSION: Our study demonstrates the anti-arthritic activity of orally administered XA while pointing to a possible mechanism of its anti-inflammatory action.

Endocannabinoid system and its modulation of brain, gut, joint and skin inflammation.

The discovery of endogenous cannabinoid receptors CB1 and CB2 and their endogenous ligands has generated interest in the endocannabinoid system and has contributed to the understanding of the role of the endocannabinoid system. Its role in the normal physiology of the body and its implication in pathological states such as cardiovascular diseases, neoplasm, depression and pain have been subjects of scientific interest. In this review the authors focus on the endogenous cannabinoids, and the critical role of cannabinoid receptor signaling in neurodegeneration and other inflammatory responses such as gut, joint and skin inflammation. This review also discusses the potential of endocannabinoid pathways as drug targets in the amelioration of some inflammatory conditions. Though the exact role of the endocannabinoid system is not fully understood, the evidence found much clearly points to a great potential in exploiting both its central and peripheral pathways in disease management. Cannabinoid therapy has proven promising in several preclinical and clinical trials.

Acetic Acid-Induced Ulcerative Colitis in Sprague Dawley Rats Is Suppressed by Hydroethanolic Extract of Cordia vignei Leaves through Reduced Serum Levels of TNF-α and IL-6.

BACKGROUND: Ulcerative colitis (UC) is a recurrent inflammatory bowel disease (IBD) that causes long-lasting inflammation on the innermost lining of the colon and rectum. Leaf decoctions of Cordia vignei have been used in traditional medicine either alone or in combination with other plant preparations to treat the disease. AIM: In this study, we investigated the effect of hydroethanolic extract of Cordia vignei have been used in traditional medicine either alone or in combination with other plant preparations to treat the disease. METHOD: Male Sprague Dawley rats received oral treatment of either saline (10 ml/kg), sulfasalazine (500 mg/kg), or CVE (30-300 mg/kg) daily for 7 days. On day 4, colitis was induced by a single intrarectal administration of 500 µl of acetic acid (4% v/v/. RESULTS: CVE significantly (P < 0.05) prevented colonic ulceration and reduced the inflammatory score. Serum levels of TNF-α and IL-6 were significantly reduced. Depletion of superoxide dismutase (SOD) and catalase (CAT) activities by acetic acid was significantly inhibited while lipid peroxidation indexed as malondialdehyde (MDA) level in the colon was reduced. However, loss of body weight was not significantly affected by treatment with CVE. CONCLUSION: This data suggest that CVE has a potential antiulcerative effect.

Allergic Airway-Induced Hypersensitivity Is Attenuated by Bergapten in Murine Models of Inflammation.

Bergapten (5-methoxypsoralen, 5-MOP) is a plant-derived furocoumarin with demonstrated anti-inflammatory action. The present study investigated its effects on allergic inflammation in two related pathways of mast cell degranulation. Compound 48/80 and lipopolysaccharide (LPS) were used to activate the IgE-independent pathway while bovine serum albumin (BSA) was used as allergen for the IgE-dependent pathway. The modulatory effect of bergapten on mast cell degranulation, neutrophil extravasation, protein concentration, lung histopathology, and oxidative stress was assessed. Bergapten at 10, 30, and 100 µg/ml for 15 min stabilized mast cells in rat mesenteric tissue from disruption in vitro and when administered in vivo at 3, 10, and 30 mg kg-1 for 1 h protected mice from fatal anaphylaxis induced by compound 48/80. Similarly, treatment of LPS-challenged mice with bergapten (3, 10, and 30 mg kg-1) for 24 h significantly decreased neutrophil infiltration into bronchoalveolar lavage fluid, mean protein concentration, and inflammatory cell infiltration of pulmonary tissues when compared to the saline-treated LPS-challenged control. In addition, lung histology of the bergapten-treated LPS-challenged mice showed significantly less oedema, congestion, and alveolar septa thickening when compared to the saline-treated LPS-challenged disease control. LPS-induced oxidative stress was significantly reduced through increased tissue activities of catalase and superoxide dismutase and reduced malondialdehyde levels on treatment with bergapten. In the triple antigen-induced active anaphylaxis, daily administration of bergapten at 3, 10, and 30 mg kg-1 for 10 days, respectively, protected previously sensitized and challenged mice against anaphylactic shock. Overall, our study demonstrates the ability of bergapten to attenuate allergic airway-induced hypersensitivity in murine models of inflammation, suggesting its possible therapeutic benefit in this condition.

Stigmasterol Alleviates Cutaneous Allergic Responses in Rodents.

The therapeutic potential of stigmasterol, a natural steroid alcohol with established immune-modulatory properties, was assessed on allergic cutaneous responses. We examined its suppressive effect on immunoglobulin E (IgE)-mediated active cutaneous anaphylaxis (ACA), compound 48/80 (C48/80)-induced pruritus, and irritant dermatitis induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Stigmasterol at 10-100 mg/kg significantly inhibited ACA with reduction in reaction area and concentration of the extravasated Evans blue dye. Given at 50 and 100 mg/kg, stigmasterol significantly inhibited C48/80-induced scratching behaviour when compared to saline-treated C48/80-injected control. Skin histopathology of injected sites confirmed that stigmasterol reduced mast cell trafficking and degranulation associated with C48/80-induced pruritus. Stigmasterol controlled inflammatory features such as ear skin oedema and neutrophilia and also reduced serum levels of TNFα induced by topical application of TPA. Epidermal layer thickening and inflammatory cell infiltration of ear skin tissue were significantly reduced by stigmasterol. Taken together, stigmasterol demonstrates significant potential as a molecule of interest in allergic skin disease therapy.

The acute anti-inflammatory action of xylopic acid isolated from Xylopia aethiopica.

Background Our earlier studies had given evidence of the traditional application of Xylopia aethiopica in the management of inflammation. The principal constituent obtained from its bio-fractionation is xylopic acid. It is a crystalline diterpene that belongs to the class of kauranes. This work sets out to investigate the anti-inflammatory potential of the xylopic acid isolated from the dried fruit of X. aethiopica. Methods A preliminary anti-inflammatory study, using the protein denaturation model, and in vivo anti-inflammatory assay were employed in the investigation of acute inflammation. The modulation of the effect of the pro-inflammatory markers histamine, serotonin, bradykinin, and prostaglandin E2 by xylopic acid was investigated by in vivo mice paw oedema models. Results Xylopic acid showed a concentration-dependent inhibition of albumen denaturation with an IC50 of 15.55 µg mL-1. Xylopic acid (10, 30, 100 mg kg-1) inhibited the maximal oedema and the average paw thickness (oedema) over the period of each study considerably for all phlogistic agents employed (i.e. carrageenan, histamine, serotonin, bradykinin, and prostaglandin E2) in the inflammation induction for both prophylactic and therapeutic protocols. Conclusion This study establishes that xylopic acid has anti-inflammatory action in acute inflammation.

Stigmasterol inhibits lipopolysaccharide-induced innate immune responses in murine models.

Stigmasterol is a naturally occurring steroid alcohol which occurs in vegetables, soya and a large variety of medicinal plants. Stigmasterol and other phytosterols have been documented as immunomodulators with huge therapeutic potential. We assessed the mitigating effect of stigmasterol on non-fatal and fatal innate immune responses in murine models after intraperitoneal challenge with an endotoxin, lipopolysaccharide, LPS. The effect of stigmasterol on LPS-induced febrile response, inflammatory cell proliferation, multiple organ damage and mortality were respectively investigated. Pretreatment with stigmasterol 10, 50 and 100mg/kg reduced total LPS-induced fever response by 39.93±10.52%, 53.05±5.84% and 77.27±6.25% respectively. Neutrophil proliferation both in blood and recovered peritoneal fluid was significantly reversed by stigmasterol at 50 and 100mg/kg. Lung and liver histopathology showed stigmasterol effectively controlled organ damage. The lung inflammation score of 9.20±0.73 for the polyethylene glycol, PEG-treated disease control mice was reduced respectively to 6.50±0.54, 4.60±0.40 and 4.10±0.42 with 10, 50 and 100mg/kg of stigmasterol. Serum levels of liver enzyme markers, alanine transaminase, ALT and aspartate transaminase, AST were consistent with the observed histological changes. Stigmasterol at 50 and 100mg/kg significantly protected mice from LPS-induced mortality with 40% survival. Overall, stigmasterol inhibits LPS-induced innate immune responses in murine models.

The Ethanolic Stem-Bark Extract of Antrocaryon micraster Inhibits Carrageenan-Induced Pleurisy and Pedal Oedema in Murine Models of Inflammation.

We investigated the antioxidant and anti-inflammatory effects of a 70% v/v ethanol extract of the stem bark of Antrocaryon micraster on murine models of carrageenan-induced pleurisy and paw oedema. Rat pleural fluid was analysed for volume, protein content, and leucocytes, while lung histology was assessed for damage. Lung tissue homogenates were assayed for glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and myeloperoxidase (MPO). Phytochemical analysis was carried out on the stem bark. Acute toxicity studies were conducted in rats. In the pleurisy model the extract (30-300 mg/kg) significantly reduced the volume and amount of proteins and leucocytes in the exudate and also protected against lung injury. Tissue level of GSH and SOD and CAT expression were increased while MDA level and MPO activity were reduced. The peak and total oedema responses were significantly suppressed when given both preemptively and curatively in the mice paw oedema test. Saponins, alkaloids, triterpenoids, and tannins were present in the stem bark. A. micraster extract exhibited no apparent acute toxicity. We conclude that the ethanolic stem-bark extract of A. micraster has antioxidant action and exhibits significant anti-inflammatory activity through suppression of pleurisy and paw oedema induced with carrageenan.

Xylopia aethiopica (Annonaceae) fruit extract suppresses Freund's adjuvant-induced arthritis in Sprague-Dawley rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Xylopia aethiopica is used in a decoction of the dried fruit to treat bronchitis, asthma, arthritis, rheumatism, headache, neuralgia and colic pain. The aim of the study is to evaluate the anti-arthritic effects of a 70% aqueous ethanol extract of the fruit of Xylopia aethiopica in a chronic inflammatory model. MATERIALS AND METHODS: Adjuvant arthritis was induced in Sprague-Dawley rats by intraplantar injection of Complete Freund's adjuvant into the right hind paw. Foot volume was measured by water displacement plethysmometry. The oedema component of inflammation was evaluated as the percentage change in paw swelling and the total oedema induced calculated as area under the time course curves. In addition to X-ray radiography, histopathology of ankle joints supported by haematological analysis was used to assess the anti-arthritic action of the extract of Xylopia aethiopica (XAE). RESULTS: Xylopia aethiopica extract (100, 300 and 600 mg kg(-1)) modified the time course curve significantly reducing hind paw oedema in the ipsilateral paw at all dose levels when administered both prophylactically and therapeutically. In addition XAE significantly suppressed the systemic spread of the arthritis from the ipsilateral to the contralateral limbs. The radiological pictures of the joints particularly metatarsal, phalanges and the ankle joint space of rats in the XAE-treated group showed protective effect against adjuvant-induced arthritis while histopathology revealed significant reduction in mononuclear infiltration, pannus formation and bone erosion. The haematological analysis in the test animals revealed significant improvement relative to the CFA model group. CONCLUSION: Xylopia aethiopica XAE suppresses joint inflammation and destruction in arthritic rats.