Effects of taraxasterol on inflammatory responses in lipopolysaccharide-induced RAW 264.7 macrophages

Optimization of methyl jasmonate and β-cyclodextrin for enhanced production of taraxerol and taraxasterol in (Taraxacum officinale Weber) cultures

CONTEXT

Taraxacum officinale Weber (TO) commonly known as "dandelion", is a tropical Asian medicinal plant which contains taraxasterol (TX) and taraxerol (TA) in its roots, which are reported to be commercially important anticancer compounds.

OBJECTIVE

The main objective of the present study was to evaluate the increase in yield of TX and TA through elicitation by addition of abiotic elictors like methyl jasmonate (MJ) and β-cyclodextrin (CD), to the root callus suspension cultures of TO.

MATERIALS AND METHODS

The root callus suspension was maintained on Murashige and Skoog's (MS) medium MS + IAA + BA + 2, 4-D (0.5 ppm + 1 ppm + 0.5 ppm). The concentrations of the abiotic elicitors MJ and CD were optimized using central composite design (CCD) and quantification of TA and TX in elicited cultures was done by High Performance Liquid Chromatography (HPLC) analysis.

RESULT

It was observed that MJ at a concentration of 0.2 mM showed good increase in content of TX to 0.032% w/w and at concentrations 0.05 mM, 0.1 mM and 0.2 mM showed similar increase in TA content to 0.018% w/w, whereas CD at the concentration of 25 mM showed highest increase in TX content to 0.036% w/w and at the concentrations of 25 mM, 50 mM showed increase in TA content to 0.023% w/w as compared to the plant root (PR) which showed content of TX as 0.0299% w/w and TA as 0.0169% w/w.

DISCUSSION AND CONCLUSION

From the present investigation it was concluded that out of the two abiotic elicitors MJ and CD, CD was found to be more effective to increase TA and TX content in Dandelion cell cultures.

Bioactive Extract from Moringa oleifera Inhibits the Pro-inflammatory Mediators in Lipopolysaccharide Stimulated Macrophages

Introduction:

Inflammation is a well-known physiological response to protect the body against infection and restore tissue injury. Nevertheless, the chronic inflammation can trigger various inflammatory associated diseases/disorder. Moringa oleifera is a widely grown plant in most tropical countries and it has been recognized traditionally for several medicinal benefits.

Objectives:

The objective of this study was to investigate the anti-inflammatory properties of M. oleifera extract on lipopolysaccharide (LPS) - stimulated macrophages.

Materials and Methods:

The anti-inflammatory effect of M. oleifera hydroethanolic bioactive leaves extracts was evaluated by assessing the inhibition of nitric oxide (NO) production during Griess reaction and the expression of pro-inflammatory mediators in macrophages.

Results:

Interestingly, we found that M. oleifera hydroethanolic bioactive leaves extract significantly inhibited the secretion of NO production and other inflammatory markers such as prostaglandin E₂, tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β. Meanwhile, the bioactive extract has induced the production of IL-10 in a dose-dependent manner. In addition, M. oleifera hydroethanolic bioactive leaves extract effectively suppressed the protein expression of inflammatory markers inducible NO synthase, cyclooxygenase-2, and nuclear factor kappa-light-chain-enhancer of activated B-cells p65 in LPS-induced RAW264.7 macrophages in a dose-dependent manner.

Conclusion:

These findings support the traditional use of M. oleifera plant as an effective treatment for inflammation associated diseases/disorders.

SUMMARY

Hydroethanolic extracts of Moringa oleifera effectively inhibit the NO production in LPS induced inflammatory model.

M. oleifera crude extracts successfully modulate the production of pro-inflammatory mediators in LPS stimulated macrophages.

M. oleifera extracts suppressed the expression of inflammatory mediators in LPS stimulated macrophages.

Identifying Chinese herbal medicine network for treating acne: Implications from a nationwide database

ETHNO-PHARMACOLOGICAL RELEVANCE

Acne is a highly prevalent inflammatory skin disease which causes patients great psychological stress, especially teenagers. Chinese herbal medicine (CHM) is commonly used to treat acne with personalized but complicated prescriptions. The aim of this study is to determine a CHM network and core CHM treatments for acne by analyzing a nationwide database.

MATERIALS AND METHODS

From January 1st to December 31st, 2011, all CHM prescriptions made for acne (ICD-9-CM code: 706.0 or 706.1) were included in this study. Visits with acupuncture, manual therapy or other treatment modalities were excluded, and CHM visits with other diagnoses were also excluded in final analysis. Association rule mining (ARM) and social network analysis (SNA) were used to explore and demonstrate a CHM network.

RESULTS

A total of 91,129 patients used traditional Chinese medicine, and 99% of them chose CHM for acne treatment. Most CHM users were teenagers, and there were twice as many female patients as male patients. A total of 279,823 CHM prescriptions were made for acne in 2011. Qing-Shang-Fang-Feng-Tang was the most commonly used CHM (31.2% of all prescriptions), and Zhen-Ren-Huo-Ming-Yin combined with Forsythia suspensa (Thunb.) Vahl. (Lian Qiao) was the most commonly used CHM-CHM combination. Thirty-one important CHM-CHM combinations were identified, and the CHM network could be built. Extensive coverage of the known pathogenesis of acne could be found in the CHM network when incorporating CHM pharmacological mechanisms into the network. Anti-inflammatory and anti-bacterial effects were commonly found in the CHM network, and CHMs with anti-androgen, anti-depressive and skin whitening effects were frequently used in combination.

CONCLUSIONS

The CHM combination patterns and core treatments for acne were disclosed in this study by applying network analysis to a CHM prescription database. These results may be beneficial for further bench or clinical studies when choosing target CHM.

Mulberry fruit prevents LPS-induced NF-κB/pERK/MAPK signals in macrophages and suppresses acute colitis and colorectal tumorigenesis in mice

Here, we investigated the impact of mulberry fruit (MBF) extracts on lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages, and the therapeutic efficacy of MBF diet in mice with dextran sulfate sodium (DSS)-induced acute colitis and MUC2^−/− mice with colorectal cancer. In vitro, LPS-induced nitric oxide (NO) production was significantly inhibited by MBF extracts via suppressing the expression of proinflammatory molecules, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1 beta (IL-β) and IL-6. Particularly, a dose-dependent inhibition on LPS-induced inflammatory responses was observed following treatment with MBF dichloromethane extract (MBF-DE), in which linoleic acid and ethyl linolenate were identified as two active compounds. Moreover, we elucidated that MBF-DE attenuated LPS-induced inflammatory responses by blocking activation of both NF-κB/p65 and pERK/MAPK pathways. In vivo, DSS-induced acute colitis was significantly ameliorated in MBF-fed mice as gauged by weight loss, colon morphology and histological damage. In addition, MBF-fed MUC2^−/− mice displayed significant decrease in intestinal tumor and inflammation incidence compared to control diet-fed group. Overall, our results demonstrated that MBF suppressed the development of intestinal inflammation and tumorgenesis both in vitro and in vivo, and supports the potential of MBF as a therapeutic functional food for testing in human clinical trials.

Pereskia aculeata Miller leaves present in vivo topical anti-inflammatory activity in models of acute and chronic dermatitis

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Pereskia aculeata Miller (Cactaceae), known as Barbados gooseberry, are used in Brazilian traditional medicine as emollients and to treat skin wounds and inflammation. This study investigated the topical anti-inflammatory activity of the hexane fraction (HF) obtained from the methanol extract of the leaves of this species in models of acute and chronic ear dermatitis in mice.

MATERIAL AND METHODS

Mice ear edema was induced by topical application of croton oil, arachidonic acid, capsaicin, ethyl-phenylpropiolate and phenol; and by subcutaneous injection of histamine. Ear biopsies were obtained to determine the levels of IL-1β, IL-6 and TNF-α cytokines by ELISA assay. Histopathological analysis was also performed to evaluate the HF activity in croton oil multiple application test. In addition, acute dermal irritation/corrosion test in rats was accomplished. HF chemical characterization was performed by GC-MS analysis.

RESULTS

HF intensively reduced the inflammatory process induced by all irritant agents used, except for arachidonic acid. This activity is related, at least in part, to the reduction of IL-6 and TNF-α cytokines levels. Moreover, when the glucocorticoid receptor antagonist mifepristone was used, HF failed to respond to the croton oil application.The results strongly suggested a glucocorticoid-like effect, which was reinforced by the presence of considerable amounts of sterol compounds identified in HF. The acute dermal irritaton/corrosion test showed no signs of toxicity.

CONCLUSIONS

This study showed that the acute and chronic anti-inflammatory activity of P. aculeata leaves is very promising, and corroborates to better understand their ethnopharmacological applications.

Protective effects of quercetin and taraxasterol against H2O2-induced human umbilical vein endothelial cell injury in vitro

Due to the association between inflammation and endothelial dysfunction in atherosclerosis, the blockage of the inflammatory process that occurs on the endothelial cells may be a useful way of preventing atherosclerosis. In the present study, human umbilical vein endothelial cells (HUVECs) were used to investigate the protective effects of quercetin and taraxasterol against H₂O₂-induced oxidative damage and inflammation. HUVECs were pretreated with quercetin or taraxasterol at concentrations ranging between 0 and 210 µM for 12 h, prior to being administered different concentrations of H₂O₂ for 4 h. Cell viability and levels of apoptosis were assessed through cell counting kit-8 (CCK-8) and terminal deoxynucleotidyl transferase dUTP nick end labeling assays, respectively, to determine the injury to the HUVECs. The viability loss in the H₂O₂-induced HUVECs was markedly restored in a concentration-dependent manner by pretreatment with quercetin or taraxasterol. This effect was accompanied by significantly decreased expression of vascular cell adhesion molecule 1 (VCAM-1) and cluster of differentiation (CD)80 for taraxasterol and that of CD80 for quercetin. In conclusion, the present study showed the protective effects of quercetin and taraxasterol against cell injury and inflammation in HUVECs and indicated that the effects were mediated via the downregulation of VCAM-1 and CD80 expression. This study has therefore served as a preliminary investigation on the anti-atherosclerotic and cardiovascular protective effects of quercetin and taraxasterol as dietary supplements.

Anti-Inflammatory Activity of Heterocarpin from the Salt Marsh Plant Corydalis heterocarpa in LPS-Induced RAW 264.7 Macrophage Cells

The inhibitory effect of three chromones 1-3 and two coumarins 4-5 on the production of nitric oxide (NO) was evaluated in LPS-induced RAW 264.7 macrophage cells. Among the compounds tested heterocarpin (1), a furochromone, significantly inhibited its production in a dose-dependent manner. In addition, heterocarpin suppressed prostaglandin E2 (PGE2) production and expression of cytokines such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6).

In vitro Hypolipidemic and Antioxidant Effects of Leaf and Root Extracts of Taraxacum Officinale

Adipose tissue dysfunction constitutes a primary defect in obesity and might link this disease to severe chronic health problems. We aimed to evaluate the antioxidant activity of three extracts from Taraxacum officinale (dandelion) as well as their effects on mature 3T3-L1 adipocytes concerning intracellular lipid accumulation and cytotoxicity, this would give indications regarding therapeutic interest of dandelion as potential anti-obesity candidate. Antioxidant activities of extracts from dandelion roots and leaves were evaluated in vitro using 1,1-diphenyl-2-picrylhyorazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) methods at the concentration range used in cellular assays (300–600 µg/mL). The influence of the extracts on mature 3T3-L1 adipocyte viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Lipid content was determined by Oil-red-O staining. The extracts showed effective antioxidant activity correlating with total flavonoid and polyphenol contents. However, the functionality level was weakly associated with the antioxidant activity. Further, our data demonstrated that mature 3T3-L1 adipocytes reduced in size and number when incubated with the extracts, which suggests a significant increase in lipolysis activity. Particularly, leaf extract and crude powdered root of dandelion reduced triglyceride accumulation in mature 3T3-L1 adipocytes to a greater extent that the extract from the root. Our study shows anti-lipogenic effects of dandelion extracts on adipocytes as well as radical scavenging and reducing activity. Importantly, along with previous results indicating that cell populations cultivated in the presence of the dandelion extracts decrease in 3T3-L1 adipogenesis capacity, these results suggests that these extracts might represent a treatment option for obesity-related diseases by affecting different processes during the adipocyte life cycle.

Occurrence of taraxerol and taraxasterol in medicinal plants

Indian soil germinates thousands of medicinal drugs that are cultivated with a purpose to obtain a novel drug. As it is a well-established fact that the structural analogs with greater pharmacological activity and fewer side-effects may be generated by the molecular modification of the functional groups of such lead compounds. This review throws light on two natural triterpenes - Taraxerol and Taraxasterol which have many important pharmacological actions including anti-cancer activity, their chemistry, biosynthesis aspects, and possible use of these compounds as drugs in treatment of cancer. A silent crisis persists in cancer treatment in developing countries, and it is intensifying every year. Although at least 50-60% of cancer victims can benefit from radiotherapy that destroys cancerous tumors, but search for the paramount therapy which will prove to be inexpensive with minimal side effects still persists. Various treatment modalities have been prescribed, along with conventional and non-conventional medicine but due to their adverse effects and dissatisfaction among users, these treatments are not satisfactory enough to give relief to patients. Hence, this review sparks the occurrence of Taraxerol (VI) and Taraxasterol (VII) in nature, so that the natural godowns may be harvested to obtain these potent compounds for novel drug development as well as discusses limitations of these lead compounds progressing clinical trials.

Quantification of taraxasterol in rat plasma by LC/MS/MS: application to a pharmacokinetic study

Taraxasterol, a pentacyclic triterpene from Taraxacum officinale, is one of the main active constituents of the herb. This study developed and validated a highly selective and sensitive liquid chromatography/tandem mass spectrometry for the determination of taraxasterol in rat plasma over the range of 9.0-5000 ng/mL. Chromatographic separation was achieved on a C18 (4.6 × 50 mm, 5.0 µm) column with methanol-isopropanol-water-formic acid (80:10:10:0.1, v/v/v/v) as mobile phase with an isocratic elution. The flow rate was 0.7 mL/min. After adding cucurbitacin IIa as an internal standard (IS), liquid-liquid extraction was used for sample preparation using ethyl acetate. The atmospheric pressure chemical ionization source was applied and operated in positive ion mode. Selected reaction monitoring mode was used for the quantification of transition ions m/z 409.4 → 137.1 for taraxasterol and m/z 503.4 → 113.1 for IS. The mean recoveries of taraxasterol in rat plasma ranged from 85.3 to 87.2%. The matrix effects for taraxasterol were between 98.5 and 104.0%. Intra- and inter-day precision were both <11.8%, and the accuracy of the method ranged from -7.0 to 12.9%. The method was successfully applied to a pharmacokinetic study of taraxasterol after oral administration of 7.75, 15.5 and 31.0 mg/kg in rats.

Taraxasterol inhibits IL-1β-induced inflammatory response in human osteoarthritic chondrocytes

Osteoarthritis (OA), a chronic degenerative joint disease, is a leading cause of disability among elderly patients. Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been shown to have anti-inflammatory effects. However, the protective effect of taraxasterol on OA remains unclear. In order to provide a scientific basis for the applicability of taraxasterol in OA, the anti-inflammatory effects of taraxasterol on IL-1β-stimulated osteoarthritic chondrocytes were investigated. Chondrocytes were pretreated with taraxasterol 1h before IL-1β treatment. The productions of MMP-1, MMP3, MMP13, PGE2 and NO were measured by ELISA and Griess reaction. The expression of COX-2, iNOS, and NF-κB was detected by western blot analysis. Our results demonstrated that taraxasterol dose-dependently suppressed MMP-1, MMP3, MMP13, PGE2 and NO production induced by IL-1β. The expression of COX-2 and iNOS was also inhibited by taraxasterol. Western blot analysis showed that taraxasterol suppressed IL-1β-induced NF-κB activation in a dose-dependent manner. Taken together, we found that taraxasterol protected human chondrocytes by inhibiting MMPs, NO and PGE2 production. Taraxasterol may be a useful agent for prevention and treatment of OA.

Box-Behnken design for optimum extraction of biogenetic chemicals from P. lanceolata with an energy audit (thermal × microwave × acoustic): a case study of HPTLC determination with additional specificity using on-line/off-line coupling with DAD/NIR/ESI-MS

INTRODUCTION

The genus Pluchea comprises about 80 species distributed worldwide, out of them, only Pluchea lanceolata (DC.) Oliv. & Hiern, is used extensively in the traditional system of India. No chromatographic method is available for its quality.

OBJECTIVES

To perform the energy audit for the extraction of biogenetic pentacyclic triterpene, its acetate and sterol from P. lanceolata utilising organic and four alternative solvents. Additionally to resolve the uncertainty of TLC determination, on-line/off-line coupling with a diode-array detector (DAD), and near-infrared (NIR) and electrospray ionisation (ESI) MS was introduced.

METHODS

The extraction of taraxasterol (Tx), taraxasterol acetate (TxAc) and stigmasterol (St) from P. lanceolata was performed using three energy modes. The effects of different operating parameters were studied for optimum extraction yield using the design of experiments, that is, the central composite design and Box-Behnken design. In addition to the retention factor (Rf ) and visible spectral matching, two additional optical spectroscopic techniques, that is, NIR and ESI-MS, were applied for extended specificity.

RESULTS

The method was developed for Tx, TxAc and St determination using HPTLC at 645 nm. The optimum extraction yield of targeted compounds was found to be higher with organic solvents than eco-friendly surfactants. The pulse ultrasonic assisted extraction (PUAE) has resulted in optimum extraction of compounds comparable to hot extraction. Both NIR and ESI-MS provided extended specificity in determination.

CONCLUSION

The 5/1-PUAE was determined to be effective, reproducible, simple and energy efficient for the determination of Tx, TxAc and St in P. lanceolata. The offline coupling of NIR and ESI-MS with HPTLC led to considerable improvement in specificity.

Effects of taraxasterol on iNOS and COX-2 expression in LPS-induced RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Taraxasterol was isolated from the Chinese medicinal herb Taraxacum officinale which has been frequently used as a remedy for inflammatory diseases. Our previous study has shown that taraxasterol inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in RAW 264.7 macrophages. To elucidate the underlying mechanism responsible for these effects, in the present study, we investigated the effects of taraxasterol on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, and mitogen-activated protein kinases (MAPKs) signaling pathway in LPS-induced RAW 264.7 macrophages.

MATERIALS AND METHODS

RAW 264.7 cells were pretreated with 2.5, 5 and 12.5 μg/ml of taraxasterol 1 h prior to treatment with 1 μg/ml of LPS. The mRNA expression levels of iNOS and COX-2 were examined by RT-PCR. The protein expression levels of iNOS and COX-2, and the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and c-Jun N-terminal kinase (JNK) MAPKs were measured by Western blot.

RESULTS

The mRNA and protein expression levels of iNOS and COX-2 were inhibited by taraxasterol in a concentration-dependent manner. Further studies revealed that taraxasterol suppressed the phosphorylation of ERK1/2 and p38 in LPS-induced RAW 264.7 macrophages.

CONCLUSIONS

These results indicate that taraxasterol inhibits iNOS and COX-2 expression by blocking ERK1/2 and p38 MAPKs signaling pathway.

A survey of chinese medicinal herbal treatment for chemotherapy-induced oral mucositis

Oral mucositis is one of the common side effects of chemotherapy treatment with potentially severe implications. Despite several treatment approaches by conventional and complementary western medicine, the therapeutic outcome is often not satisfactory. Traditional Chinese Medicine (TCM) offers empirical herbal formulas for the treatment of oral ulceration which are used in adaptation to chemotherapy-induced mucositis. While standard concepts for TCM treatment do not exist and acceptance by conventional oncologists is still low, we conducted a review to examine the evidence of Chinese herbal treatment in oral mucositis. Eighteen relevant studies on 4 single herbs, 2 combinations of 2 herbs, and 11 multiherbal prescriptions involving 3 or more compounds were included. Corresponding molecular mechanisms were investigated. The knowledge about detailed herbal mechanisms, especially in multi-herbal prescriptions is still limited. The quality of clinical trials needs further improvement. Meta-analysis on the existent database is not possible but molecular findings on Chinese medicinal herbs indicate that further research is still promising for the treatment of chemotherapy-induced oral mucositis.

Antimalarial and safety evaluation of Pluchea lanceolata (DC.) Oliv. & Hiern: in-vitro and in-vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

Many of the effective therapeutic strategies have been derived from ethnopharmacologically used natural products. Pluchea lanceolata is an herb employed in Indian folk medicine for malaria like fever but it lacks proper pharmacological intervention.

AIM OF THE STUDY

To evaluate antimalarial and safety profile of Pluchea lanceolata: an in-vitro, in-vivo for its ethnopharmacological validation.

MATERIALS AND METHODS

Methanol, butanol, ethyl acetate, chloroform, hexane extracts and its isolate, taraxasterol acetate (TxAc) were obtained from air dried aerial part of Pluchea lanceolata. These were tested in-vitro against chloroquine-sensitive strain of Plasmodium falciparum NF54 by measuring the parasite specific lactate dehydrogenase activity. The most potent hexane extract and TxAc were further validated for in-vivo antimalarial and safety evaluation. TxAc, a pentacyclic-triterpene isolated from the most active fraction was further evaluated with special emphasis on inflammatory mediators involved in malaria pathogenesis. Murine malaria was induced by intra-peritoneal injection of Plasmodium berghei infected red blood cells to the male Swiss inbred mice. Mice were orally treated following Peters 4-Day suppression test. In-vivo antimalarial efficacy was examined by evaluating the parasitaemia, percent survival, mean survival time, blood glucose, haemoglobin and pro-inflammatory mediators involved in malaria pathogenesis.

RESULTS

Hexane extract and TxAc showed promising antimalarial activity in-vitro and in-vivo condition. TxAc attributed in inhibition of the pro-inflammatory cytokines as well as afford to significant increase in the blood glucose and haemoglobin level when compared with vehicle treated infected mice. We have not observed the synergistic action of combinations of chloroquine and TxAc from our experimental results. In-vitro and in-vivo safety evaluation study revealed that hexane extract is non toxic at higher concentration.

CONCLUSION

Present study further validates the ancient Indian traditional knowledge and use of Pluchea lanceolata as an antimalarial agent. Study confirms the suitability of Pluchea lanceolata as a candidate for further studies to obtain a prototype for antimalarial medicine.

Sargachromenol from Sargassum micracanthum inhibits the lipopolysaccharide-induced production of inflammatory mediators in RAW 264.7 macrophages

During our ongoing screening program designed to determine the anti-inflammatory potential of natural compounds, we isolated sargachromenol from Sargassum micracanthum. In the present study, we investigated the anti-inflammatory effects of sargachromenol on lipopolysaccharide (LPS)-induced inflammation in murine RAW 264.7 macrophage cells and the underlying mechanisms. Sargachromenol significantly inhibited the LPS-induced production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in a dose-dependent manner. It also significantly inhibited the protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner in LPS-stimulated macrophage cells. Further analyses showed that sargachromenol decreased the cytoplasmic loss of inhibitor κBα (IκBα) protein. These results suggest that sargachromenol may exert its anti-inflammatory effects on LPS-stimulated macrophage cells by inhibiting the activation of the NF-κB signaling pathway. In conclusion, to our knowledge, this is the first study to show that sargachromenol isolated from S. micracanthum has an effective anti-inflammatory activity. Therefore, sargachromenol might be useful for cosmetic, food, or medical applications requiring anti-inflammatory properties.

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 10mg/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.

Molecular mechanisms underlying the in vitro anti-inflammatory effects of a flavonoid-rich ethanol extract from chinese propolis (poplar type)

China produces the greatest amount of propolis but there is still lack of basic studies on its pharmacological mechanisms. Our previous study found that ethanol extract from Chinese propolis (EECP) exerted excellent anti-inflammatory effects in vivo but mechanisms of action were elusive. To further clarify the possible mechanisms underlying the anti-inflammatory effects of Chinese propolis (poplar type), we utilized EECP to analyze its chemical composition and evaluated its potential anti-inflammatory effects in vitro. High-performance liquid chromatography (HPLC) profile indicated that EECP contained abundant flavonoids, including rutin, myricetin, quercetin, kaempferol, apigenin, pinocembrin, chrysin, and galangin. Next we found that EECP could significantly inhibit the production of NO, IL-1β, and IL-6 in lipopolysaccharide- (LPS-) stimulated RAW 264.7 cells and suppress mRNA expression of iNOS, IL-1β, and IL-6 in a time- and dose-dependent manner. Furthermore, we found that EECP could suppress the phosphorylation of IκBα and AP-1 but did not affect IκBα's degradation. In addition, using a reporter assay, we found that EECP could block the activation of NF-κB in TNF-α-stimulated HEK 293T cells. Our findings give new insights for understanding the mechanisms involved in the anti-inflammatory effects by Chinese propolis and provide additional references for using propolis in alternative and complementary therapies.