Anti-inflammatory effects of ethanolic extract from Lagerstroemia indica on airway inflammation in mice

Aim of the study

In the present study, we investigated whether the Lagerstroemia indica Linn (LI) extract has an anti-inflammatory effect on lung inflammation in ovalbumin-induced asthmatic mice.

Materials and methods

The LI extract was obtained from dried and powdered whole plants of LI using 80% ethanol. ELISA was performed to evaluate cytokine concentration. BALB/c mice were used as a mouse model of asthma after asthmatic induction by ovalbumin sensitization and inhalation. We examined the effects of the LI extract on leukocyte infiltration and mucus secretion using cell count and histological stain.

Results

The amount of cytokines, such as interleukin (IL)-2, IL-4, IL-5, IL-13, and TNF-α, was increased in Jurkat cells using the extract from house dust mites. Increased cytokine concentrations were inhibited by the LI extract. The LI extract suppressed the increased expression of IL-6 after treatment with mite extract of EoL-1 cells and THP-1 cells. In an in vivo experiment using asthmatic mice, the LI extract significantly inhibited leukocytosis and eosinophilia in bronchoalveolar lavage (BAL) fluid and lung tissue samples. The LI extract inhibited the increase in mucus secretion by goblet cells, blocked the production of reactive oxygen species in BAL fluid cells, and blocked the protein expression of IL-5 in BAL fluid. The concentration of ovalbumin-specific IgE in BAL fluid was weakly inhibited by the LI extract.

Conclusions

These results suggest that the LI extract may be used as a valuable agent for treating allergic diseases such as asthma due to its anti-inflammatory property.     

Anti-diabetic activity of Chiliadenus iphionoides

Ethnopharmacological relevance

Chiliadenus iphionoides (Boiss. & Blanche) Brullo (Asteraceae), a small aromatic shrub found throughout Israel, is used traditionally in the treatment of diabetes mellitus. In this study, Chiliadenus iphionoides anti-diabetic activity was characterized using cellular and animal models.

Materials and methods

Pancreatic β cells, adipocytes, and skeletal myotubes were treated with an ethanolic extract of Chiliadenus iphionoides to study the extract's effects on insulin secretion and glucose uptake. The sand rat (Psammomys obesus) was used to study Chiliadenus iphionoides acute and long term effects in vivo. An oral starch tolerance test was performed as well as a 30 day feeding study.

Results

Chiliadenus iphionoides extract increased insulin secretion in β cells as well as glucose uptake in adipocytes and skeletal myotubes. The extract also displayed hypoglycemic activity in the diabetic sand rat.

Conclusions

Chiliadenus iphionoides exhibits considerable anti-diabetic activity, although the mechanism of action remains to be determined.     

In vitro antioxidant, antiplatelet and anti-inflammatory activity of Carpobrotus rossii (pigface) extract

Ethnopharmacological relevance

Carpobrotus rossii (CR) has a history of use as a food and therapeutic agent by Australian indigenous peoples and early European settlers and is believed to contain a number of pharmacologically active polyphenolic compounds.

Aims of the study

Oxidation of low density lipoprotein (LDL), platelet aggregation, and inflammation contribute to the development and progression of atherosclerosis. The aim of the present study was to investigate the antioxidant, antiplatelet and anti-inflammatory activity of CR extract using human blood components.

Materials and methods

An assay employing in vitro copper-induced oxidation of serum lipids was used to assess antioxidant activity of CR extract (and tannin, flavonoid and pre- and post-flavonoid fractions). The effects of CR extract on ADP- and collagen-induced platelet aggregation, and on basal (unstimulated) and lipopolysaccharide (LPS)- and phytohaemagglutinin A (PHA)-stimulated cytokine release from peripheral blood mononuclear cells (PBMC) were also investigated.

Results

CR extract increased the lag time of serum oxidation (maximum of ∼4-fold at 20 μg/ml) in a concentration-dependent manner. The antioxidant activity resided only in the tannin and post-flavonoid fractions. CR had no effect on ADP-induced platelet aggregation, but significantly decreased collagen-induced platelet aggregation. LPS, but not PHA, significantly increased the release of IL-1β and TNF-α from PBMC. CR extract alone inhibited monocyte chemoattractant protein (MCP)-1 release and in the presence of LPS, inhibited IL-10, TNF-α and MCP-1 release compared to LPS alone.

Conclusion

CR has significant in vitro antioxidant, antiplatelet and, potentially, anti-inflammatory activity.     

Suppression of dust mite extract and 2,4-dinitrochlorobenzene-induced atopic dermatitis by the water extract of Lindera obtusiloba

Ethnopharmacological relevance

The Lindera obtusiloba has been used in traditional medicine for the treatment of inflammation and dermatitis. In this study, we investigated the effect of topical application of Lindera obtusiloba water extract (LOWE) on the house dust mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD).

Materials and methods

We established AD model in BALB/c mice by repeated local exposure of DFE/DNCB to the ears. After a topical application of LOWE on the skin lesions, the epidermal thickness, mast cell infiltration, and serum immunoglobulin E (IgE) and histamine were measured. In addition, the gene expression of interleukin (IL)-4, IL-13, IL-31, and tumor necrosis factor (TNF)-α in the ears was assayed.

Results

LOWE reduced AD symptoms based on ear thickness, histopathological analysis, and serum IgE levels. LOWE inhibited mast cell infiltration into the ear and elevation of serum histamine in AD model. Moreover, LOWE suppressed DFE/DNCB-induced expression of IL-4, IL-13, IL-31, and TNF-α in the ears.

Conclusions

Our results showed that topical application of LOWE exerts beneficial effects in AD symptoms, suggesting that LOWE might be a candidate for the treatment of AD.     

Analgesic compounds from Scorzonera latifolia (Fisch. and Mey.) DC.

Ethnopharmacological relevance

A traditional mastic named yak? sak?z? prepared from the roots of Scorzonera latifolia (Fisch. and Mey.) DC. is used as a folk remedy for treatment of pain in Turkish folk medicine.

Aim of the study

To isolate and identify the compounds responsible for the antinociceptive activity of S. latifolia using bioassay-guided fractionation.

Materials and methods

The methanolic extract of the S. latifolia roots was prepared and subjected to isolation procedures such as solvent-solvent partitioning and column chromatography. Writhing and tail-flick tests were used to determine the antinociceptive activity.

Results

The n-hexane fraction of the S. latifolia root methanolic extract showed potent antinociceptive activity in both writhing and tail-flick tests. Three compounds were isolated from n-hexane fraction using bioassay-guided chromatographic purification. Isolated compounds were the triterpene taraxasteryl myristate, taraxasteryl acetate, and fern-7-en-3-β-one, structures were elucidated by means of MS and NMR techniques. Both taraxasterol derivatives showed promising antinociceptive activity when compared to reference compounds.

Conclusion

Results of the present study support the usage of S. latifolia in Turkish folk medicine. Both plant root extract and the isolated compounds showed promising antinociceptive activities. Our results suggested that antinociceptive activity of the plant extract is probably caused by the synergistic interaction of the isolated compounds.     

Inhibition of matrix metalloproteinases related to metastasis by diosgenyl and pennogenyl saponins

Ethnopharmacological relevance

Diosgenyl and pennogenyl saponins isolated from Rhizoma Paridis, showed pro-apoptosis and immunoregulation with antitumor activity in cultured cells and animal systems.

Aim of the study

To evaluate their anti-metastatic mechanism on cancer cells and discuss their structure-activity relationship on anti-tumor effect.

Materials and methods

This research used the wound healing and migration assay to detect their anti-invasive effect on B16 melanoma cells. Through the gelatin zymography assay, immunofluorescence analysis and western blot, saponins exhibited different levels of protein expression inhibition of MMP-1, -2, -3, -9 and -14.

Results

Through the analysis, diosgenyl and pennogenyl saponins inhibited the metastasis of B16 melanoma cells. Diosgenyl saponins also showed strong suppression of enzyme activity of MMP-2 and -9. Different saponins exhibited different levels of inhibition on MMP expression.

Conclusions

17-α OH increases the sensitivity of diosgenyl saponins to the membrane-bound protease which can stimulate proMMP-2 activation, but it also decreases the anti-metastatic activity of diosgenyl saponin. Furthermore, their combination might provide a potential therapeutic modality for metastasis.     

Encecalol angelate, an unstable chromene from Ageratum conyzoides L.: total synthesis and investigation of its antiprotozoal activity

Ethnopharmacological relevance

In agreement with ethnomedicinal reports, the dichloromethane extract of Ageratum conyzoides L. (Asteraceae) was recently shown to be of considerable activity against Trypanosoma brucei rhodesiense, the etiologic agent of East African Human Trypanosomiasis (East African Sleeping Sickness). Isolated compounds, namely, methoxylated flavonoids as well as the chromene derivative encecalol methyl ether, were less active than the crude extract. The activity of the extract was found to decrease considerably while stored in solution. An unstable compound was detected in the fresh extract by HPLC, which was converted rapidly into the encecalol methyl ether while stored in methanolic solution. This compound, deemed to represent a constituent with antitrypanosomal activity, could not be isolated from the extract in intact form.

Aim of the study

To elucidate the structure of this unstable compound and to investigate its potential role in the antitrypanosomal activity of the total extract.

Materials and Methods

UHPLC/ESI-qQTOF MSMS and NMR data of the degraded product indicated its chemical identity as encecalol angelate (1) which was therefore prepared by total synthesis via a linear six steps synthesis, starting from resorcinol and 2-methylbut-3-en-2-ol.

Results

Total synthesis, in an overall yield of 15%, led to pure 1, which was chromatographically and spectroscopically identical with the natural product. The compound degraded in methanol with a half-life of approximately 6 h to yield encecalol methyl ether (2). The antiprotozoal activity of synthetic encecalol angelate against T. brucei rhodesiense as well as T. cruzi, Leishmania donovani and Plasmodium falciparum was investigated and found to be quite low.

Conclusions

The synthetic approach applied here for the first time also provides access to the related bioactive chromenes encecalin (7) and encecalol (8) with improved yields compared with reported methods. Encecalol angelate, however, is most likely not responsible for the high antitrypanosomal activity of the freshly prepared dichloromethane extract of A. conyzoides.     

Preliminary study of antidiabetic activity of the methanolic leaf extract of Axonopus compressus (P. Beauv) in alloxan-induced diabetic rats

Ethnopharmacological relevance

Axonopus Compressus is commonly used by the people of Southern Nigeria to treat different ailment such as common cold and diabetes. This study therefore, evaluated the anti-diabetic effect of the methanolic leaf extract of the plant.

Materials and methods

Diabetes was induced in the rats by intraperitoneal (i.p.) injection of alloxan monohydrate at the dose of 180 mg/kg. Three test doses of the extract (250, 500 and 1000 mg/kg) administered per os through gastric gavage to the rats were used in the study. The activity was compared to a standard reference drug (glibenclamide, 2 mg/kg) and a negative control. Blood from the tail snip was used to measure the effects of the extract and drug at 0, 1, 3 and 6 h using autoanalyzer (AccuCheck Active^®) glucose kit.

Results

Methanolic leaf extract of Axonopus compressus at all the doses (250, 500 and 1000 mg/kg) used caused a respective time dependent and significant (p < 0.0001) reduction (by 31.5%, 19.8% and 24.5%) of the blood glucose levels in the diabetic rats when compared to the negative control group at the 6th hour. However, the reference drug (glibenclamide, 2 mg/kg) decreased the blood glucose levels by 69.9% and the tween 20 solution (negative control) increased the blood glucose level by 15.2% at the 6th hour. Moreso, the extract at the different test doses caused various degrees of reduction of the blood glucose levels of the test rats at 1st, 3rd and 6th hours when compared to the negative control rats.

Conclusion

The findings suggest that Axonopus compressus may possess antidiabetic property.     

Inonotus obliquus extracts suppress antigen-specific IgE production through the modulation of Th1/Th2 cytokines in ovalbumin-sensitized mice

Ethnopharmacological relevance

Chaga mushroom (Inonotus obliquus, IO) has been used as a folk remedy for cancer, digestive system diseases, and other illnesses in Russia and Eastern Europe.

Aim of the study

In the present study, we investigated the immunomodulating effects of IO through in vivo and ex vivo studies.

Materials and methods

Serum immunoglobulins (IgE, IgG₁, and IgG_2a) and cytokines (interleukin (IL)-4, interferon (IFN)-γ, and IL-2) were measured in concanavalin A (ConA)-stimulated splenocytes and CD4⁺ T cells. The nitric oxide (NO) secretion of lipopolysaccharide (LPS)-stimulated peritoneal macrophages was also measured after oral administration of 50, 100, or 200 mg kg⁻¹ d⁻¹ IO hot water extract (IOE) to ovalbumin (OVA)-sensitized BALB/c mice.

Results

We found that the OVA-induced increase in serum IgE and IgG_2a was significantly suppressed when IOE was orally administered after the second immunization with OVA. ConA stimulation in spleen cells isolated from OVA-sensitized mice treated with 100 mg kg⁻¹ IOE resulted in a 25.2% decrease in IL-4 production and a 102.4% increase in IFN-γ, compared to the controls. Moreover, IL-4, IFN-γ, and IL-2 were significantly reduced after ConA stimulation in isolated CD4⁺T cells. We also determined that IOE inhibits the secretion of NO from LPS-stimulated peritoneal macrophages ex vivo.

Conclusions

We suggest that IO modulates immune responses through secretion of Th1/Th2 cytokines in immune cells and regulates antigen-specific antibody production.     

Sheng-Ma-Ge-Gen-Tang (Shoma-kakkon-to) inhibited cytopathic effect of human respiratory syncytial virus in cell lines of human respiratory tract

Ethnopharmacological relevance

Sheng-Ma-Ge-Gen-Tang (SMGGT; Shoma-kakkon-to) has been used against pediatric viral infection for thousands of year in ancient China. However, it is unknown whether SMGGT is effective against human respiratory syncytial virus (HRSV).

Aim of the study

HRSV is a major pediatric viral pathogen of low respiratory tract infection without effective management. This study tested the hypothesis that SMGGT effectively inhibited cytopathy induced by HRSV.

Materials and methods

Effect of the crude extract of SMGGT on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Ability of SMGGT to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA).

Results

Crude extract of SMGGT dose-dependently inhibited HRSV-induced plaque formation. The crude extract was more effective when given before viral infection (p < 0.0001). It inhibited viral attachment dose-dependently (p < 0.0001) and could increase heparin effect on viral attachment. Furthermore, it was synergistic with very low-dose heparin on viral attachment. In addition, the crude extract time-dependently and dose-dependently (p < 0.0001) inhibited HRSV internalization into HEp-2 cells. Epithelial cells secrete IFN-β and TNF-α to counteract viral infection. The crude extract could stimulate epithelial cells to secrete these cytokines beforehand and become resistant to viral infection. It also stimulated IFN-β to defense HRSV after viral inoculation.

Conclusions

Sheng-Ma-Ge-Gen-Tang could be effective to manage HRSV infection in young children.     

Inhibition effect of Gynura procumbens extract on UV-B-induced matrix-metalloproteinase expression in human dermal fibroblasts

Ethnopharmacological relevance

Gynura procumbens Merr. (Asteraceae) has been used as a traditional remedy for various skin diseases in certain areas of Southeast Asia.

Aim of the study

In order to evaluate the protective activity of Gynura procumbens extract on skin photoaging and elucidate its mode of action.

Materials and methods

Matrix-metalloproteinase (MMP)-1 and -9 expressions were induced by UV-B irradiation in human primary dermal fibroblasts. MMP-1 expression level was measured by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Zymography was employed for evaluating the enzymatic activity of MMP-9. Anti-inflammatory activity and anti-oxidative capacity of the extract were evaluated by ELISA and dichlorodihydrofluorescein diacetate (DCF-DA) assay.

Results

The ethanolic extract of Gynura procumbens inhibited MMP-1 expression up to 70% compare to negative control group. The enzymatic activity of MMP-9 was inhibited around 73% by the treatment of 20 μg/mL of the extract. The extract markedly reduced the production of reactive oxygen species (ROS). Gynura procumbens extract showed an inhibitory effect on releasing pro-inflammatory cytokines (IL-6 and IL-8) in human HaCat keratinocyte.

Conclusion

The ethanolic extract of Gynura procumbens inhibited MMP-1 and MMP-9 expressions induced by UV-B irradiation via inhibition of pro-inflammatory cytokine mediator release and ROS production.     

Tanshinones isolated from the rhizome of Salvia miltiorrhiza inhibit passive cutaneous anaphylaxis reaction in mice

Ethnopharmacological relevance

The rhizome of Salvia miltiorrhiza Bunge (SM, family Labiatae), which contains tanshinones as main constituents, has been used as a cardiovascular and anti-inflammatory agent in Chinese medicine.

Aim of the study

This study aimed to elucidate anti-allergic effects of the root of Salvia miltiorrhiza Bunge (SM, family Labiatae) and its main constituents, tanshinones, against passive cutaneous anaphylaxis (PCA) reaction.

Materials and methods

PCA reaction was induced by IgE-antigen complex (IAC) in ICR mice. Protein expression of IL-4 and TNF-α in rat basophilic leukemia (RBL)-2H3 cells was performed by enzyme-linked immunosorbent assay and NF-κB and c-jun (AP-1) activation assayed by immunoblot.

Results

Tanshinones inhibited the PCA reaction and reduced IL-4 and TNF-α production in mice as well as in IAC-stimulated RBL-2H3 cells. Tanshinones also inhibited NF-κB and AP-1 activation in RBL-2H3 cells stimulated with IAC. Among tested tanshinones, tanshinone I exhibited the most potent inhibition, followed by 15,16-dihydrotanshinone I, tanshinone IIA and cryptotanshinone.

Conclusions

SM and tanshinones may ameliorate the PCA reaction by inhibiting the allergic cytokines IL-4 and TNF-α via NF-κB and AP-1 pathways.     

Selective Th1 upregulation by ethyl acetate fraction of Labisia pumila

Aim of the study

Labisia pumila has rejuvenating properties that help women to regain the strength and vigour after giving birth (Burkill, 1935) leading us to speculate that Labisia pumila might also modulate the immune matrix as it is one of the important aspect of healthy state of the living body.

Materials and methods

Studies were carried out for the evaluation of pro-inflammatory cytokines in murine neutrophils followed by expression of T cell-surface markers and corresponding intracellular expression of cytokines related to T helper1 (Th1) and T helper 2 (Th2) activity.

Results

The ethyl acetate fraction (A001/3b) obtained from ethanolic extract of leaves of Labisia pumila at graded doses (in vitro) showed increased expression of TNF-α, IL-6 and IL-12. IL-12 is a strong inducer of Th1 response in activated CD4+ T cells and accordingly T cell studies were carried out (in vivo). These specific studies showed A001/3b to cause marked stimulation of CD4+ T helper cells and related cytokine expression like IL-2 and IFN-gamma (a potent Th1 inducer), thereby, having a predominant Th1 upregulation pathway. This was further validated by suppression of IL-4 and IL-10 expression which are the Th2 pathway cytokines.

Conclusion

This study showed ethyl acetate fraction (A001/3b) of Labisia pumila to have Th1 upregulating activity and suggests its possible usefulness as a therapeutic agent in immune compromised patients.     

Topical application of porcine placenta extract inhibits the progression of experimental contact hypersensitivity

Aim of study

Placenta extract features as a composition of ointments used for skin beautification, dermatological diseases and skin dryness. However, little evidence has been cited about its underlying mechanisms of action by which it exerts a beneficial role in dermatological diseases in vivo. In this study, we intended to test the effect of topical application of porcine placenta extract in mouse model of contact hypersensitivity and elucidate its mechanism of action.

Materials and methods

To test the in vitro effect of porcine placenta extract, RAW 264.7 cells were cocultured with porcine placenta extract and stimulated with LPS (1 μg/ml) and the expression of inflammatory mediator TNF-α was estimated by RT-PCR at the mRNA level and by intracellular staining at the protein level. To further test in vivo efficacy, porcine placenta extract was topically applied to the mice with experimental skin hypersensitivity. For in vivo studies placenta extract in gel form was topically applied to ear of DNCB-induced contact hypersensitivity mouse model everyday for 2 weeks and progression of the disease was estimated by following criteria: (a) ear thickness, (b) serum IgE level by ELISA, (c) histological examination of ear tissue by H&E staining and (d) cytokine profile of total cells and CD4⁺ T cells by real time PCR.

Results

Topical application of porcine placenta extract on mouse ears with contact hypersensitivity decreased the severity and progression of the disease manifested by reducing ear swelling, inflammation and edema. Histological evaluation showed that placenta extract treatment reduced lymphocyte infiltration in the ear tissues. Protective effect of placenta extract is also associated with down-regulation of serum IgE level and inflammatory cytokine production (IL-1β, IFN-γ, TNF-α, IL-4, IL-12 and IL-17) in total lymph node cells and CD4⁺ T cells.

Conclusions

Our data indicate that protective effect of porcine placenta extract in contact hypersensitivity is mediated by inhibition of the inflammatory responses and IgE production, suggesting a potential therapeutic application of porcine placenta extract to modulate skin inflammation.     

Protective effect of a polyphenolic rich extract from Magnolia officinalis bark on influenza virus-induced pneumonia in mice

Ethnopharmacological relevance

Magnolia officinalis bark is used in traditional Chinese medicine for the treatment of cough, colds, fever, chronic bronchitis and stomach ailments.

Aim of the study

To investigate therapeutic effects of polyphenol rich extract from M. officinalis bark (MPE) in influenza virus A-infected mice, and to provide evidence for the inflammation response and immunomodulatory potential during infection.

Materials and methods

Mice were infected with influenza virus A (IVA) and MPE at doses of 10 and 20 mg/kg were orally administrated daily for 5 days after challenge. The levels of serum L-6 and TNF-α were determined by ELISA while protein expressions of NF-κB and TLR3 were detected by western blotting analysis.

Results

MPE exhibited significant therapeutical effects on reducing levels of serum NO, IL-6 and TNF-α, inhibiting pneumonia, decreasing lung viral titers and sensitizing IVA-induced apoptosis through down-regulation of NF-κB and TLR3 protein expression in the lung tissue of IVA-infected mice.

Conclusions

MPE could exhibit preventive and therapeutical effects on IVA-infected mice as a suppressor of the production of inflammatory mediators, NO and pro-inflammatory cytokines, TNF-α and IL-6. These effects appeared to be mediated, at least in part, by an inhibition of TLR3 and NF-κB activation. Therefore, MPE could provide a safe and effective therapeutic approach for influenza and its subsequent viral pneumonia.     

In vitro screening on β-amyloid peptide production of plants used in traditional medicine for cognitive disorders

Aim of the study

The aim of the study was to investigate the activity on β-amyloid peptide production of crude extracts of 9 plant species traditionally used in Benin or in Madagascar for the treatment of cognitive disorders, in order to select candidates for Alzheimer's disease treatment.

Materials and methods

For each species, hexane, dichloromethane, ethyl-acetate and water extracts were tested, at non-toxic concentrations, on CHO cells overexpressing the human neuronal β-amyloid peptide precursor (APP695) to measure variations of APP processing (by Western-blotting) and, for the most active, of Aβ-amyloid production (by ECLIA).

Results

We observed, at non-toxic concentrations, a significant increase in CTF/APP ratio with Oldenlandia affinis cyclotide-enriched fraction, Prosopis africana EtOAc extract, Pterocarpus erinaceus aqueous extract and Trichilia emetica hexane extract. We also showed that the Pterocarpus erinaceus extract significantly decreased Aβ production, displaying effects similar to those of DAPT (γ-secretase inhibitor) on APP processing, but may act on another inhibition site.

Conclusion

These active extracts are worth further studies to isolate the compounds responsible for the observed activities, to analyze their mode of action and determine their clinical potentials.     

Increased sexual motivation in female rats treated with Humulus lupulus L. extract

Aim of the study

To evaluate the influence of Humulus lupulus extract on sexual behavior in female rats.

Materials and methods

Ovariectomized rats hormonally primed with estradiol benzoate (1.5 μg/rat) and progesterone (500 μg/rat) were acutely treated by oral gavage with Humulus lupulus extract dosed at 5, 10 and 25 mg/kg and then tested for partner preference and sexual receptivity.

Results

The administration of Humulus lupulus extract at the highest dose significantly increased the preference for the stimulus male during the partner preference test and the number of proceptive behaviors during the receptivity test, without affecting the lordosis response.

Conclusions

Humulus lupulus extract increased sexual motivation in hormone-primed female rats.