Effects of taraxasterol on ovalbumin-induced allergic asthma in mice

Ethnopharmacological relevance

Taraxasterol was isolated from the Chinese medicinal herb Taraxacum officinale which has been frequently used as a remedy for inflammatory diseases. In the present study, we determined the in vivo protective effect of taraxasterol on allergic asthma induced by ovalbumin (OVA) in mice.

Materials and methods

Mice were sensitized and challenged with OVA, and were orally treated daily with taraxasterol at 2.5, 5 and 10 mg/kg from day 23 to 27 after sensitization. The number of inflammatory cells in bronchoalveolar lavage fluid (BALF) was determined. Th2 cytokine interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13) production in BALF and OVA-specific immunoglobulin E (IgE) production in sera were measured using ELISA. Histological changes in lung tissues were examined using hematoxylin and eosin (H&E) and periodic acid-Schiff staining (PAS). Airway hyperresponsiveness (AHR) to inhaled methacholine was assessed.

Results

Taraxasterol dramatically decreased the total inflammatory cell and main inflammatory cell counts, reduced the production of Th2 cytokine IL-4, IL-5, IL-13 in BALF and OVA-specific IgE in sera, and suppressed AHR in a dose-dependent manner. Histological studies demonstrated that taraxasterol substantially suppressed OVA-induced inflammatory cells infiltration into lung tissues and goblet cell hyperplasia in airways.

Conclusions

This finding suggests that taraxasterol protects against OVA-induced allergic asthma in mice.     

Attenuation of airway hyperreactivity and T helper cell type 2 responses by coumarins from Peucedanum praeruptorum Dunn in a murine model of allergic airway inflammation

Ethnopharmacological relevance

The root of Peucedanum praeruptorum Dunn (PPD) is a commonly used traditional Chinese medicine for the treatment of asthma. Its major constituents, coumarins, were presumed to be responsible for its efficacy.

Aim of the study

The potential of coumarins from PPD (CPPD) as anti-asthma agent was investigated.

Materials and methods

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) to induce allergic airway inflammation. CPPD was administered intragastrically before every OVA challenge. Airway reactivity to the intravenous administration of acetylcholine chloride was measured 48 h after final OVA inhalation. Airway inflammation was evaluated by leukocyte counts of bronchoalveolar lavage fluid (BALF) and histopathological analysis of lung lesions. Levels of interleukin (IL)-4, IL-5, IL-10, IL-13 and IFN-γ in BALF and OVA-specific immunoglobulin (Ig) E in serum, and activity of eosinophil peroxidase (EPO) in lung was measured. The percentage of CD4⁺CD25⁺Foxp3⁺ regulatory T cells among CD4⁺ T cells in spleen was analyzed by flow cytometry.

Results

Compared with model group, CPPD significantly reduced airway hyperreactivity and airway eosinophilic inflammation, improved pathologic lesion of the lungs, reduced levels of IL-4, IL-5, IL-13 in BALF and OVA-specific IgE in serum, inhibited the activities of EPO in lung, and up-regulated levels of IL-10 and IFN-γ in BALF as well as the percentage of CD4⁺CD25⁺Foxp3⁺ regulatory T cells in spleen.

Conclusion

CPPD can significantly suppress OVA-induced airway inflammation, airway hyperreactivity and Th2 predominant response in mice, showing great therapeutic potential for the treatment of allergic asthma.     

Immunomodulatory activity of Asparagus racemosus on systemic Th1/Th2 immunity: Implications for immunoadjuvant potential

Ethnopharmacological relevance

Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations.

Aim of the study

To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals.

Materials and methods

We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside^®) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls.

Results

Treatment with ARE (100 mg/(kg b.w. p.o.)) resulted in significant increase of CD3⁺ and CD4/CD8⁺ percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes.

Conclusion

The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.     

Propolis effect on Th1/Th2 cytokines production by acutely stressed mice

Aim of the study

Propolis has gained special attention due to its biological properties, however, little is known about its immunomodulatory effects in stress conditions. The purpose of this study was to investigate propolis effect on Th1/Th2 cytokines production by spleen cells of acutely stressed mice. Serum corticosterone concentration was determined as a stress indicator.

Materials and methods

Male BALB/c mice were submitted to restraint stress and treated with propolis (200 mg/kg) for 3 days. Supernatants of splenocytes cultures were assessed for Th1/Th2 cytokines determination.

Results

Regarding Th1 cytokines production, no alterations were seen in IL-2 production; however, IFN-γ production was inhibited in stressed mice, even when treated with propolis. As to Th2 cytokines, IL-4 was inhibited in stressed mice, but normal levels were seen when these animals were treated with propolis. No significant differences were found in IL-10 production between the experimental groups. Stressed groups (treated or not with propolis) showed higher corticosterone concentrations in comparison to control group.

Conclusions

Data suggest that propolis treatment was not able to counteract the stress-induced immunosuppressive effect on IFN-γ production; however, propolis showed an immunorestorative role, increasing IL-4 production in stressed mice, favoring humoral immune response during stress. Since the exact mechanisms of this natural product on immune system are still unclear, further studies are still required for a better comprehension of propolis use as a therapeutic alternative against the stress-induced negative effects that could lead to the development of various diseases.     

Anti-inflammatory and anti-asthmatic effects of Viola mandshurica W. Becker (VM) ethanolic (EtOH) extract on airway inflammation in a mouse model of allergic asthma

Aim of the study

We investigated the efficacy of Viola mandshurica W. Becker (VM) ethanolic (EtOH) extract in the treatment of bronchial asthma in an ovalbumin (OVA)-induced asthmatic BALB/c mouse model.

Materials and methods

Female BALB/c mice were sensitized with intraperitoneal (i.p.) ovalbumin (OVA) on days 0 and 14, and were next given intranasal OVA on days 28–30. Randomized treatment groups of sensitized mice received VM EtOH extract, dexamethasone, or placebo, orally, from days 28 to 30.

Results

VM EtOH extract significantly inhibited increases in total immunoglobulin E (IgE) and cytokines IL-4 and IL-13 levels in serum and bronchoalveolar lavage fluid (BALF), and also effectively suppressed airway hyperresponsiveness (AHR), eosinophilia, and mucus hypersecretion, in mice with OVA-induced asthma.

Conclusions

The results suggest that VM EtOH extract and allied extracts could be useful herbal medicines for asthma treatment, and that VM may also be a valuable lead material for anti-asthma drug development.     

Bambusae Caulis in Taeniam extract reduces ovalbumin-induced airway inflammation and T helper 2 responses in mice

Ethnopharmacological relevance

Bambusae Caulis in Taeniam (BC) was known as traditional herbal medicine with anti-inflammatory property in the Orient.

Aim of the study

Allergic asthma is inflammatory disease of airways associated with enhanced T helper (Th) 2 lymphocytes responses to allergens, leading to eosinophilic infiltration and elevated serum IgE levels. Although there were some studies that BC extract had an anti-inflammatory property, there was no study on asthma. In present study, we investigated the suitability of BC extract as a therapeutic candidate in the treatment of allergic airway disease in ovalbumin-induced asthma model.

Materials and methods

Balb/C mice (female, 6 weeks old) were treated by ovalbumin sensitization and nebulization, and used as asthma model. The number of eosinophil in bronchoalveolar lavage (BAL) fluid and the degree of eosinophila were investigated by hematoxylin and eosin stain and the infiltration of inflammatory cells into lung tissues was examined by staining by hematoxylin and eosin solution. The levels of interleukin (IL)-4 in BAL fluid, immunoglobulin E (IgE) in serum, interferon (IFN)-γ and IL-4 production in splenocyte culture from Balb/C mice (not treated, 6 weeks old) that incubated with or without BC extract for 48 h were determined by enzyme-linked immunosorbent assay.

Results

The level of eosinophils was decreased by treatment of the animals with BC extract (40 mg/kg) and correspondingly, a significantly lowered degree of eosinophila was also reported (p < 0.01). In lung tissue, BC extract reduced the increased immune cell infiltration induced by OVA (p < 0.05). Furthermore, the levels of IL-4 and IgE in BAL fluid or serum up-regulated by OVA was decreased by BC extract. Finally, IFN-γ production was significantly increased (p < 0.01), while IL-4 production significantly decreased (p < 0.01), after treatment of the culture supernatants of splenocytes with BC extract.

Conclusions

These results indicated that BC extract reduces OVA-induced airway inflammation and Th 2 response in mice, suggesting that BC extract can be a therapeutic candidate for allergic airway disease, including asthma.     

Inhibitory effects of Duchesnea chrysantha extract on ovalbumin-induced lung inflammation in a mouse model of asthma

Ethnopharmacological relevance

Duchesnea chrysantha (D. chrysantha) is a herb with anti-oxidative, anti-inflammatory and immune-enhancing properties.

Aim of the study

Asthma is an inflammatory disease of the lungs, and the hallmarks of the disease are increased inflammatory cell infiltration into the airways and poor respiratory function. Although there is the possibility that D. chrysantha may have an inhibitory effect on lung inflammation, the effects of D. chrysantha on asthma have not been fully investigated. In the present study, we investigated the anti-inflammatory activity of D. chrysantha extract (Dc extract) on lung inflammation in a murine model of ovalbumin-induced asthma.

Materials and methods

Dc extract was obtained from dried and powdered whole plants of D. chrysantha using 80% ethanol. BALB/c mice induced by ovalbumin sensitization and nebulization were used as a mouse model of asthma. RT-PCR and ELISA were performed to measure mRNA and protein expression of cytokines. We examined the effects of Dc extract on leukocyte infiltration and mucus secretion using periodic acid-Schiff staining as well as hematoxylin and eosin staining.

Results

Dc extract significantly inhibited leukocytosis and eosinophilia in the bronchoalveolar lavage (BAL) fluid (p < 0.01). Dc extract significantly reduced the elevated infiltration of inflammatory cells (p < 0.05) and inhibited the increased mucus secretion, despite the absence of significant value. Although Dc extract weakly inhibited the mRNA expression of IL-4, IL-5, IL-13, and eotaxin, it strongly inhibited the protein expression of IL-5 (p < 0.05) and eotaxin (p < 0.01) in BAL fluid. Ovalbumin-specific IgE levels in the serum and BAL fluid were blocked by Dc extract (p < 0.05).

Conclusions

These results suggest the possibility that Dc extract can exert suppressive effects on asthma and may provide evidence that Dc extract is a useful agent for the treatment of allergic airway disease.     

Protective effects of Ulmus davidiana var. japonica against OVA-induced murine asthma model via upregulation of heme oxygenase-1

Aim of the study

Traditionally, the stem and root bark of Ulmus davidiana var. japonica (Ulmaceae) are Korean herbal medicines used for anti-inflammatory and anticancer therapy. In this study, we investigated the protective effects of Ulmus davidiana var. japonica ethanolic extract (UD) in a murine asthma model. Furthermore, we determined whether heme oxygenase (HO)-1 is required for the protective activity of UD.

Materials and methods

Airways of ovalbumin (OVA)-sensitized mice exposed to OVA challenge developed eosinophilia, mucus hypersecretion and increased cytokine levels. UD was applied 1 h prior to OVA challenge. Mice were administered UD orally at doses of 100 and 200 mg/kg once daily on days 18–23. Bronchoalveolar lavage fluid (BALF) was collected 48 h after the final OVA challenge. Levels of interleukin (IL)-4 and IL-5 in BALF were measured using enzyme-linked immunosorbent assays (ELISAs). Lung tissue sections 4 μm in thickness were stained with Mayer's hematoxylin and eosin for assessment of cell infiltration and mucus production with PAS (periodic acid shift reagent) staining, in conjunction with ELISA, immunohistochemistry and Western blot analyses for HO-1 protein expression.

Results and conclusion

Orally administered UD significantly inhibited the number of OVA-induced inflammatory cells and IgE production, along with reduced T-helper (Th)2 cytokine levels, such as IL-4 and IL-5, in BALF and lung tissue. In addition, UD induced a marked decrease in OVA-induced reactive oxygen species (ROS), inflammatory cell infiltration and mucus production in lung tissue. These effects were correlated with HO-1 mRNA and protein induction. Our results indicate that UD protects against OVA-induced airway inflammation, at least in part, via HO-1 upregulation.     

Matrine attenuates allergic airway inflammation and eosinophil infiltration by suppressing eotaxin and Th2 cytokine production in asthmatic mice

Ethnopharmacological relevance

Matrine has been isolated from Sophora flavescens, and found to show anti-inflammatory effects in macrophages and anti-cachectic effects in hepatomas. The present study investigated whether matrine suppressed eosinophil infiltration and airway hyperresponsiveness (AHR) in mice, and decreased the inflammatory response of tracheal epithelial cells.

Materials and methods

BALB/c mice were sensitized and challenged with ovalbumin to induce allergic asthma in mice. These asthmatic mice were given various doses of matrine by intraperitoneal injection. Additionally, activated human tracheal epithelial cells (BEAS-2B cells) were treated with matrine, and evaluated for levels of proinflammatory cytokines and chemokines.

Results

We found that matrine significantly decreased AHR, and suppressed goblet cell hyperplasia, eosinophil infiltration, and inflammatory response in the lung tissue of asthmatic mice. Matrine also reduced the levels of Th2 cytokines and chemokines in bronchoalveolar lavage fluid, and suppressed OVA–IgE production in serum. Furthermore, matrine treatment of activated BEAS-2B cells decreased production of proinflammatory cytokines and eotaxins, as well as suppressed ICAM-1 expression and thus adhesion of eosinophils to inflammatory BEAS-2B cells in vitro.

Conclusions

Our findings suggest that matrine can improve allergic asthma in mice, and therefore has potential therapeutic potential in humans.     

Production of Th1- and Th2-dependent cytokines induced by the Chinese medicine herb, Rhodiola algida, on human peripheral blood monocytes

Ethnopharmacological relevance

Rhodiola algida, an herb ingredient used in Chinese medicine, has been clinically proven to be effective in enhancing human immune responses.

Aim of study

This study attempted to identify the potential immunomodulatory effect of Rhodiola algida extract in human immune system in vitro, and to examine its underlying molecular effects.

Materials and methods

Firstly, the bioactive marker compound salidroside was used for standardization of Rhodiola algida extract by reversed-phase HPLC. Secondly, the regulation of human immune responses was investigated in human peripheral blood monocytes. A series of cytokines known to play important roles in the human immune responses were examined.

Results

The current study provided quantitative assay for the marker compound, salidroside, in the Rhodiola algida extract for ensuring the quality consistency of Rhodiola algida used in the following experiments. Biological assay indicated that Rhodiola algida stimulates human peripheral blood lymphocytes and its underlying immunomodulatory effects probably through its regulation of IL-2 in Th1 cells and IL-4, IL-6, IL-10 in Th2 cells.

Conclusion

The findings may enable us to further explain the pharmacological properties in Chinese medicine and make Rhodiola algida a very promising immunomodulating agent.     

Phytochemical profiles and biological activity evaluation of Zanthoxylum bungeanum Maxim seed against asthma in murine models

Ethnopharmacological relevance

Zanthoxylum bungeanum Maxim seed (ZBMS) has been used in Traditional Chinese Medicine (TCM) as an ingredient of polyherbal formulations for the treatment of inflammation and asthma. The aim of this study was to analyze the major composition and to evaluate the anti-asthma activity of ZBMS.

Materials and methods

Some murine models including acetylcholine/histamine-induced asthma, ovalbumin-induced airway inflammation, ear edema and toe swelling measurement, citric acid-induced cough, and anti-stress abilities were investigated to fully study the anti-asthma activity of ZBMS.GC chromatography was also performed to analyze the major fatty acid composition of ZBMS.

Results

The results demonstrated that the major fatty acid composition of ZBMS includes oleic acid (20.15%), linoleic acid (26.54%), and α-linolenic acid (30.57%), which was the leading component of ZBMS, and that the total fatty acid content of ZBMS was 77.27%. The murine models demonstrated that ZBMS displays a protective effect on guinea pig sensitization, a dose-dependent inhibition of the increases in R_L and decreases in C_dyn, which resulted in the relief of auricle edema and toe swelling in mice and anti-stress activity.

Conclusion

Our results validate the traditional use of ZBMS for the treatment of asthma and other inflammatory joint disorders, and suggest that ZBMS has potential as a new therapeutic agent for asthma management.     

Essential oil from Pterodon emarginatus seeds ameliorates experimental autoimmune encephalomyelitis by modulating Th1/Treg cell balance

Ethnopharmacological relevance

Pterodon emarginatus Vogel is a medicinal plant commonly used in Brazilian traditional medicine as a folk therapy due to its immunosuppressive, anti-inflammatory, anti-rheumatic, healing, tonic and depurative activities. The essential oil (EO) of Pterodon emarginatus is composed of volatile aromatic terpenes and phenyl propanoids, mainly, β-elemene and β-caryophyllene sesquiterpenes. Here we reported the effects and some underlying mechanisms of action of EO during murine model of MS, the experimental autoimmune encephalomyelitis (EAE).

Materials and methods

EO (50 and 100 mg/kg) was orally administered during the entire period of development of EAE (preventive treatment, day 0–25). In vitro and in vivo immunological responses were evaluated by ELISA, immunohistochemistry, immunofluorescence and flow cytometry.

Results

We provide evidence that EO of Pterodon emarginatus (100 mg/kg, p.o.) significantly attenuates neurological signs and also the development of EAE. Furthermore, at the same dose EO consistently inhibited Th1 cell-mediated immune response and upregulated Treg response in vitro. Moreover, the EO inhibited both microglial activation and expression of iNOS, associated with inhibition of axonal demyelization and neuronal death during the development of the disease.

Conclusion

This is the first experimental evidence showing that oral administration of EO consistently reduces and limits the severity and development of EAE, mainly, through the modulation of Th1/Treg immune balance, and might represent a helpful new tool for control immunoinflammatory conditions, such as MS.     

Antihistaminic and antiallergic actions of extracts of Solanum nigrum berries: Possible role in the treatment of asthma

Ethnopharmacological relevance

Berries of the plant Solanum nigrum Linn (Solanaceae) are used for the treatment of asthma in folk medicine and ancient books.

Aim of study

To evaluate potential of the plant berries in the treatment of asthma.

Materials and methods

Petroleum ether, ethanol and aqueous extracts of S. nigrum berries (50, 100 and 200 mg/kg, i.p.) were screened for the treatment of asthma by the various methods viz. effect on clonidine and haloperidol induced catalepsy, milk-induced leucocytosis and eosinophilia, mast cell stabilizing activity in mice and studies on smooth muscle preparation of guinea pig ileum (in vitro). Active petroleum ether extract was standardized by HPTLC.

Results

The petroleum ether extract of S. nigrum berries inhibited clonidine-induced catalepsy significantly but not haloperidol-induced catalepsy. Petroleum ether extract significantly inhibited increased leukocyte and eosinophil count due to milk allergen and showed maximum protection against mast cell degranulation by clonidine. Petroleum ether extract resisted contraction induced by histamine better than other extracts. All the results are dose dependant. Active petroleum ether extract showed presence of antiasthmatic compound, β-sitosterol.

Conclusion

The petroleum ether extract of S. nigrum berries can inhibits parameters linked to the asthma disease.     

Effect of Astragali-Cordyceps Mixtura on TGF-β/Smad signal pathway in the lung of asthma airway remodeling

Aim of the study

We try to find out the influence of traditional Chinese Medicine Astragali-Cordyceps Mixtura (ACM) on TGF-β/Smad signal pathway in the lung of asthma airway remodeling.

Materials and methods

Mice were sensitized and challenged by OVA to establish a model of asthma. To assess the effects of ACM on the mice, animals of the ACM groups were treated with ACM. Data were achieved by using techniques as follow: counting cell number of BALF, assaying the amount of collagen deposition by Masson's staining, performing RT-PCR and immunohistochemistry for mRNA and protein expression of TGF-β1, Smad3 and Smad7.

Results

The depositions of collagen in airway wall greatly increased at the model group compared with that of the normal group. In contrast, these decreased at the ACM groups. As compared with the control group, TGF-β1 expression also decreased at both mRNA and protein level at the ACM-M group versus increased both at the model group. Whereas, Smad7 significantly decreased only at the model group and partly restored at the ACM-M group.

Conclusions

ACM greatly improves the symptoms of asthma airway remodeling by inhibiting the expression of TGF-β1 and upregulating the amount of Smad7.     

The effect of the extract of Crocus sativus on tracheal responsiveness and plasma levels of IL-4, IFN-γ, total NO and nitrite in ovalbumin sensitized Guinea-pigs

Ethnomedical relevance

Anti-inflammatory, anti oxidant and effect of Crocus sativus (C. sativus) on Th₁/Th₂ balance were described previously.

Aim of the study

The preventive effects of the extract of Crocus sativus on tracheal responsiveness and plasma levels of IL-4, IFN-γ, total NO and nitrite were examined on sensitized guinea pigs.

Materials and methods

Five groups of sensitized guinea pigs to ovalbumin (OVA), were given drinking water containing three concentrations of the extract of Crocus sativus, dexamethasone (S+D) or alone (group S). Tracheal responses (TR) of control animals (group C) and sensitized guinea pigs (n=6, for each group) to methacholine, OVA and the levels of IL-4, IFN-γ, total NO and nitrite in serum were examined.

Results

The TR to both methacholine and OVA, the levels of serum IL-4, total NO and nitrite in S guinea pigs were significantly increased but that of IFN-γ and IFN-γ/IL-4 ratio (Th₁/Th₂ balance) were decreased compared to the controls (p<0.05 to p<0.001). In the treated animals with dexamethasone and all concentrations of the extract, TR to both methacholine and OVA, IL-4, total NO and nitrite were significantly decreased but IFN-γ and IFN-γ/IL-4 ratio increased compared to S group (p<0.05 to p<0.001). The effects of the highest concentration of the extract was greater than those of other concentrations and the effect of dexamethasone (p<0.05 to p<0.01).

Conclusions

These results not only showed a preventive effect of C. sativus extract on tracheal responses and serum levels of inflammatory mediators in sensitized guinea pigs but also showed increased Th₁/Th₂ balance.