Vitexin inhibits inflammation in murine ovalbumin-induced allergic asthma.

Vitexin is an important component of various medicinal plants frequently used to treat asthma, such as Crataegus spp., Vitex spp., Passiflora spp., and Echinodorus spp. However, there is no information about the vitexin potential as anti-asthmatic. The aim of the present work was to evaluate the anti-hypersensitive activity of vitexin in a murine ovalbumin (OVA)-induced allergic asthma model. Mice were sensitized to OVA by i.p. injection on days 1st and 10th, followed by a daily challenge with OVA using a nebulizer, from days 19th to 24th. Vitexin or dexamethasone were orally administered 1h before each OVA challenge. Vitexin attenuates migration induced by OVA-hypersensitivity of eosinophil, neutrophil, and mononuclear cells in bronchoalveolar lavage fluid (BALF). Histological analysis of the lungs shows that vitexin suppressed leukocyte infiltration, mucus production and pulmonary edema. Increases in Th2 cytokines in BALF in OVA-induced asthma is also attenuated by vitexin, as well as plasma levels of IgE. Overall, these results suggest that vitexin can suppress OVA-induced allergic inflammation in mice and provide a strong rationale for further developing vitexin as a candidate treatment for allergic hypersensitivity. These data corroborate the popular use of vitexin-rich plants for asthma treatment.

Hydroethanolic extract from Echinodorus scaber Rataj leaves inhibits inflammation in ovalbumin-induced allergic asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Echinodorus scaber, Alismataceae, is popularly known in Brazil as "chapéu-de-couro". The plant leaves are used by the population as decoction, infusion, or maceration in bottled spirits, to treat inflammatory respiratory diseases. AIM OF THE STUDY: To investigate the anti-inflammatory mechanism of the hydroethanolic extract of leaves of Echinodorus scaber (HEEs) in allergic asthma. A phytochemical analysis of the extract was performed as well. MATERIALS AND METHODS: The leaves of Echinodorus scaber were prepared by maceration in 75% ethanol. Preliminary phytochemical analysis was carried out using basic classical methods, and the secondary metabolites detected in HEEs were analyzed and confirmed by high-performance liquid chromatography (HPLC). The in vivo anti-inflammatory activity of HEEs was evaluated in Swiss male albino mice sensitized and challenged by OVA. The HEEs (1, 5 and 30mg/kg, p.o.) was administered to mice twice a day, 1h before the challenge, from days 19 through 24. The mechanism of action of HEEs was studied by evaluating the levels of TH2 cytokines (IL-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF) and IgE production in blood plasma. Histopathological changes triggered by OVA-sensitization/challenge in the lung tissue were also investigated. RESULTS: HEEs reduced total leukocyte, eosinophil, neutrophil, and mononuclear cell counts at all doses tested, with maximum effect at 30mg/kg (73.9%, 75.9%, 75.5%, and 65.2% reduction, p<0.001, respectively). Increases in TH2 cytokine secretion (IL-4, IL-5 and IL-13) and in IgE levels were also attenuated by HEEs. Preliminary phytochemical screening seems to indicated the presence of phenolic compounds, flavonoids and alkaloids. HPLC analyses evidenced the presence of phenolic compounds, such as gallic acid, rutin and vitexin. CONCLUSION: Our findings provided pharmacological preclinical evidence for the popular use of the leaves of Echinodorus scaber in allergic inflammation. Its anti-inflammatory effect was dependent on the decrease in migratory inflammatory cells, and both TH2 cytokines and IgE levels. It is suggested that vitexin, gallic acid and rutin, known anti-inflammatory compounds, may participate in the anti-asthamtic effect of the HEEs, by acting jointly along with other components present in the extract.

Mandevilla longiflora (Desf.) Pichon improves airway inflammation in a murine model of allergic asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Mandevilla longiflora, popularly known as "velame" in central Brazil, is a subshrub widely distributed in South America. Its xylopodium is used in the form of a decoction or infusion to treat inflammation and other ailments. AIM OF THE STUDY: This study aimed to evaluate the anti-inflammatory potential of M. longiflora in an in vivo model of ovalbumin-induced immediate hypersensitivity, identifying its effects on leukocyte infiltration, IgE and LTB4 levels, and Th2 cytokine production. In addition, HPLC fingerprint of the extract was performed. MATERIAL AND METHODS: The hydroethanolic extract 70% of M. longiflora (HEMI) was obtained by maceration of the plant xylopodium. Swiss mice were sensitized by i.p. injection OVA-aluminium hydroxide on days 1 and 10. Nine days after the last sensitisation animals were challenged for 6 consecutive days with OVA solution for 20min daily in a closed chamber under continuous flow of aerosol. The animals were treated with HEMl (20, 50 and 200mg/kg p.o.), 2 times per day, and euthanized 24h later. Animals treated with vehicle (2% Tween-20) or dexamethasone were used as negative and positive controls, respectively. The recruitment of inflammatory cells into the pulmonary cavity was evaluated by counting cells present in broncho-alveolar lavage fluid (BALF). Lung tissue was also collected for histopathology and infiltration analysis. Quantification of IL-4, IL-5 and IL-13 from the BALF, and IgE, and LTB4 from plasma, were conducted by immunoassay. RESULTS AND CONCLUSIONS: The HEMl attenuated leukocyte migration into the airways, which was evidenced by a decrease in eosinophils, neutrophils and mononuclear cells, both in BALF quantification and by histopathological analysis, as well as decreasing the concentrations of IL-4, IL-5, IL-13, IgE and LTB4. All of these events are typical of air-mucosa inflammatory disease. These findings scientifically evidence for the first time the ethnopharmacological use of M. longiflora to treat chronic inflammatory events, such as asthma, and suggest a potential therapeutic use or complementary therapy for this plant extract.

Vitexin reduces neutrophil migration to inflammatory focus by down-regulating pro-inflammatory mediators via inhibition of p38, ERK1/2 and JNK pathway.

BACKGROUND: Vitexin is a flavonoid found in plants of different genus such as Vitex spp. and Crataegus spp. Despite being an important molecule present in phytomedicines and nutraceuticals, the mechanisms supporting its use as anti-inflammatory remains unclear. PURPOSE: To investigate the cellular and molecular mechanisms involved in acute anti-inflammatory effect of vitexin with regard to neutrophil recruitment and macrophages activation. METHODS: Anti-inflammatory properties of vitexin were evaluated in four models of neutrophil recruitment. The regulation of inflammatory mediators release was assessed in vivo and in vitro. Vitexin (5, 15 and 30 mg/kg p.o) effects on leukocytes migration to peritoneal cavity induced by zymosan (ZY), carrageenan (CG), n-formyl-methionyl-leucyl-phenylalanine (fMLP) and lipopolysaccharide (LPS) were evaluated in Swiss-Webster mice and the effects on the levels of TNF-α, IL-1ß and IL-10 cytokines, and NO concentration were in the LPS-peritonitis. RAW 264.7 macrophages viability were determined by Alamar Blue assay as well as the capacity of vitexin in directly reducing the concentrations of TNF-α, IL-1ß, IL-10, NO and PGE2. Additionally, vitexin effects upon the transcriptional factors p-p38, p-ERK1/2 and p-JNK were evaluated by western blotting in cells activated with LPS. RESULTS: Vitexin was not cytotoxic (IC50 > 200 µg/ml) in RAW 264.7 and at all doses tested it effectively reduced leukocyte migration in vivo, particularly neutrophils in the peritoneal lavage, independently of the inflammatory stimulus used. It also reduced TNF-α, IL-1ß and NO releases in the peritoneal cavity of LPS-challenged mice. Vitexin had low cytotoxicity and was able to reduce the releases of TNF-α, IL-1ß, NO, PGE2 and increase in IL-10 release by LPS activated RAW 264.7 cells. Vitexin was also able to regulate transcriptional factors for pro-inflammatory mediators, reducing the expression of p-p38, p-ERK1/2 and p-JNK in LPS-elicited cells. CONCLUSIONS: Vitexin presented no in vitro cytotoxicity. Inhibition of neutrophil migration and pro-inflammatory mediators release contributes to the anti-inflammatory activity of vitexin. These effects are associated with the inactivation of important signaling pathways such as p38, ERK1/2 and JNK, which act on transcription factors for eliciting induction of inflammatory response.

Leishmanicidal effect of Spiranthera odoratíssima (Rutaceae) and its isolated alkaloid skimmianine occurs by a nitric oxide dependent mechanism.

Leishmaniasis is one of the neglected diseases. High cost, systemic toxicity, and diminished efficacy due to development of resistance by the parasites has a negative impact on the current treatment options. Thus, the search for a new, effective and safer anti-leishmanial drug becomes of paramount importance. Compounds derived from natural products may be a better and cheaper source in this regard. This study evaluated the in vitro anti-leishmanial activity of Spiranthera odoratíssima (Rutaceae) fractions and isolated compounds, using promastigote and amastigote forms of different Leishmania species. J774 A.1 macrophage was used as the parasite host cell for the in vitro assays. Evaluations of cytoxicity, nitric oxide (NO), interleukin-10 and in silico analysis were carried out. In vitro experiments showed that the fruit hexanic fraction (Fhf) and its alkaloid skimmianine (Skm) have a significant (P<0·001) effect against L. braziliensis. This anti-L. braziliensis activity of Fhf and Skm was due to increased production of NO and attenuation of IL-10 production in the macrophages at concentrations ranging from 1·6 to 40·0 µg/ml. The in silico assay demonstrated significant interaction between Skm and amino acid residues of NOS2. Skm is thus a promising drug candidate for L. braziliensis due to its potent immunomodulatory activity.