Inhibitory effects of adlay bran (Coix lachryma-jobi L. var. ma-yuen Stapf) on chemical mediator release and cytokine production in rat basophilic leukemia cells

Ethnopharmacological relevance

Adlay (Job's tears, Coix lachryma-jobi L. var. ma-yuen Stapf) has long been used in China to treat rheumatism.

Aim of the study

We investigated the anti-allergic effects of adlay bran on rat basophilic leukemia (RBL)-2H3 cells.

Materials and methods

To evaluate the anti-allergic effects of adlay bran, the release of histamines and cytokines were measured using ELISA. To explore the mechanism of these effects, the protein expression levels were determined using western blotting.

Results

A 40.8 μg/mL concentration of the ethyl acetate fraction of the ethanolic extracts of adlay bran (ABE-EtOAc) effectively inhibited mast cell degranulation. The 40–100% EtOAc/Hex subfractions of ABE-EtOAc inhibited histamine release with an IC₅₀ of 71–87 μg/mL. Moreover, the ABE-EtOAc subfractions suppressed the secretion of interleukin (IL)-4, IL-6 and tumor necrosis factor-α in the RBL-2H3 cells, indicating that adlay bran can inhibit cytokine secretion in the late phase of the allergic reaction. In addition, adlay bran reduced the intracellular production of reactive oxygen species, inhibited the phosphorylation of Akt and decreased the expression of protein kinase C. Furthermore, six phenolic acids and one flavone were isolated. Of these compounds, luteolin showed the most potent inhibitory activity (IC₅₀ = 1.5 μg/mL).

Conclusion

Adlay bran extract reduced the release of histamines and cytokines and suppressed the production of Akt. These combined effects influenced the signal transduction in RBL-2H3 cells, thereby revealing the mechanisms of the anti-allergic effects of adlay.     

Antiallergic effect of KOB03, a polyherbal medicine, on mast cell-mediated allergic responses in ovalbumin-induced allergic rhinitis mouse and human mast cells

Ethnopharmacological relevance

KOB03 is a polyherbal medicine consisting of five different herbs and has commonly been used for the treatment of various allergic diseases. However, its precise anti-allergic effect and mechanism remain unknown.

Aim of the study

The aim of this study was to investigate the effect of KOB03 on allergic responses through the regulation of mast-cell mediated allergic inflammation.

Materials and methods

To determine the effect of KOB03 on mast cell-mediated allergic reactions, we investigated the parameter changes of in vivo models such as compound 48/80-induced systemic anaphylaxis and ovalbumin (OVA)-induced allergic rhinitis, and the release of allergic inflammatory mediators such as histamine, immunoglobulin (Ig) E, and inflammatory cytokines via the MAPKs and NF-kappaB pathways.

Results

The oral administration of KOB03 at doses of 100 and 200 mg/kg inhibited histamine release and mortality in compound 48/80-induced anaphylactic rats. KOB03 also improved rhinitis symptoms, inhibited the histopathological changes of nasal mucosa, and decreased the serum levels of histamine, OVA-specific IgE and TNF-α in OVA-induced allergic rhinitis in mice. In vitro, KOB03 suppressed compound 48/80-induced histamine release by blocking mast cell degranulation. In addition, KOB03 inhibited the production of inflammatory cytokines such as TNF-α, IL-1β, IL-6 and IL-8 in PMA/A23187-stimulated HMC-1 mast cells by suppressing their gene expression and blocking the ERK1/2 and p38 MAPK and NF-κB pathways.

Conclusions

These results suggest that KOB03 has an anti-allergic effect by modulating mast cell-mediated allergic responses in allergic rhinitis.     

Mast cell stabilization and antihistaminic potentials of Curculigo orchioides rhizomes

Aim of the study

To investigate the mast cell stabilization and antihistaminic activities of the rhizomes of Curculigo orchioides (COR). Extract of Curculigo orchioides Gaertn. (Fam. Amaryllidaceae) has been reported to possess immunostimulant, and anti-inflammatory potentials. In Indian traditional system of medicine it is also used as anti-asthmatic and anti-inflammatory.

Materials and methods

Estimation of histamine release is key parameter for evaluating any target for its anti-allergic potential. The stabilization potential of the alcoholic extract of COR (100–400 mg/kg) against mast cell degranulation was studied on isolated mice peritoneal mast cells. The antihistaminic activity was performed by determining the mortality rate of mice upon exposure to compound 48/80 and effect on inhibition of histamine release upon degranulation.

Results

The raised number of intact mast cells intimates that the COR stabilized the mast cell degranulation (60.96 ± 1.96%) and percentage antihistaminic potential of the extract (63.58 ± 1.8 inhibition at dose of 400 mg/kg) and it virtues further work towards the isolation of phytoconstituents from this plant.

Conclusion

This finding provides evidence that COR inhibits mast cell-derived immediate-type allergic reactions and mast cell degranulation.     

Inula japonica extract inhibits mast cell-mediated allergic reaction and mast cell activation

Ethnopharmacological relevance

The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for the treatment of bronchitis, digestive disorders, and inflammation. However, the mechanisms underlying its anti-inflammatory effects remain yet to be elucidated. The objectives of this study were 1) to assess the anti-allergic activity of the ethanol extract of flowers of Inula japonica extract (IFE) in vivo, 2) to investigate the mechanism of its action on mast cells in vitro, and 3) to identify its major phytochemical compositions.

Materials and methods

The anti-allergic activity of IFE was evaluated using mouse bone marrow-derived mast cells (BMMCs) in vitro and a passive cutaneous anaphylaxis (PCA) animal model in vivo. The effects of IFE on mast cell activation were evaluated in terms of degranulation, eicosanoid generation, Ca²⁺ influx, and immunoblotting of various signaling molecules.

Results

IFE inhibited degranulation and the generation of eicosanoids (PGD₂ and LTC₄) in stem cell factor (SCF)-stimulated BMMCs. Biochemical analysis of the SCF-mediated signaling pathways demonstrated that IFE inhibited the activation of multiple downstream signaling processes including mobilization of intracellular Ca²⁺ and phosphorylation of the mitogen-activated protein kinases (MAPKs), PLCγ1, and cPLA₂ pathways. When administered orally, IFE attenuated the mast cell-mediated PCA reaction in IgE-sensitized mice. Its major phytochemical composition included three sesquiterpenes, 1-O-acetylbritannilactone, britanin and tomentosin.

Conclusions

This study suggests that IFE modulates eicosanoids generation and degranulation through the suppression of SCF-mediated signaling pathways that would be beneficial for the prevention of allergic inflammatory diseases. Anti-allergic activity of IFE may be in part attributed particularly to the presence of britanin and tomentosin as major components evidenced by a HPLC analysis.     

Anti-diabetic activity of extract from Persea americana Mill. leaf via the activation of protein kinase B (PKB/Akt) in streptozotocin-induced diabetic rats

Ethnopharmacological relevance

The leaves of Persea americana Mill. (Lauraceae) have been popularly used in the treatment of diabetes in countries in Latin America and Africa.

Aim of the study

To investigate the hypoglycaemic properties and to determine the molecular mechanism by which the hydroalcoholic extract of the leaves of Persea americana reduce blood glucose levels in streptozotocin (STZ)-induced diabetes in rats via the enzymatic pathway of protein kinase B (PKB/Akt).

Methods

The hydroalcoholic extract of the leaves of Persea americana (0.15 and 0.3 g/kg/day), vehicle and metformin (0.5 g/kg/day) were administered orally to STZ-diabetic rats (n = 7/group) for 4 weeks. Changes in body weight, food and water intake, fasting glucose levels and oral glucose tolerance were evaluated. Phosphorylation and the expression of PKB in the liver and soleus muscle were determined by Western blot.

Results

The hydroalcoholic extract of the leaves of Persea americana reduced blood glucose levels and improved the metabolic state of the animals. Additionally, PKB activation was observed in the liver and skeletal muscle of treated rats when compared with untreated rats.

Conclusion

The results indicate that the hydroalcoholic extract of the leaves of Persea americana has anti-diabetic properties and possibly acts to regulate glucose uptake in liver and muscles by way of PKB/Akt activation, restoring the intracellular energy balance.     

In vivo study of the anti-inflammatory and antitumor activities of leaves from Plectranthus amboinicus (Lour.) Spreng (Lamiaceae)

Ethnopharmacological relevance

Plectranthus amboinicus (Lour.) Spreng is a medicinal specie often used in Brazil, especially in Northeast Region, for the treatment of several diseases including inflammations and cancer.

Aim of the study

To evaluate the anti-inflammatory and antitumor activities of the hydroalcoholic extract from leaves of P. amboinicus in an attempt to determine whether the medicinal uses are supported by pharmacological effects.

Materials and methods

Anti-inflammatory activity was determined by carrageenan-induced paw edema method. The antitumor effect was evaluated in an in vivo experimental study, using the following tumors: Sarcoma-180 and Erlich ascite carcinoma.

Results

There were statistically significant decreases (p < .05) of edema paw in at the doses of 150, 250 and 350 mg/kg (i.p.) of the hydroalcoholic extract of P. amboinicus. Similarly, the administration of P. amboinicus at the doses of 100, 150, 250 and 350 mg/kg (i.p.) inhibited the growth of sarcoma-180 and Ehrlich ascite carcinoma tumors in mice.

Conclusion

The results suggest that the hydroalcoholic extract of P. amboinicus possesses anti-inflammatory and antitumor activities, supporting the folk use of this medicinal specie.     

Inhibitory effects of Solidago chilensis Meyen hydroalcoholic extract on acute inflammation

Aim of the study

Alcoholic or hydroalcoholic preparations of the plant Solidago chilensis Meyen (Asteraceae) are employed in popular medicines to treat inflammation.The anti-inflammatory effects of the hydroalcoholic extract of aerial parts of the plant (93% ethanol) were investigated and the main components of the extract were identified.

Materials and methods

Ear oedema was induced in male Wistar rats by topical application of the chloroform fraction of latex-extract from Euphorbia milii. Leukocyte mobilisation was quantified after air-pouch inflammation evoked by oyster glycogen. Leukocyte–endothelial interactions and mast cell degranulation were quantified by intravital microscopy. The extract itself was characterised via HPLC–DAD–MS and HPLC–MS/MS.

Results

Topical (12.5–50 mg/kg) or intraperitoneal (25 or 50 mg/kg) administrations of the extract reduced ear oedema formation (>25% reduction). Intraperitoneal applications of 25 mg/kg of extract inhibited the migration of polymorphonuclear cells into the inflamed cavity (about 50%). In addition, the rolling behaviour and adherence of circulating leukocytes to postcapillary venules of the mesentery network was diminished (50%), but the mast cell degranulation in the perivascular area was not affected. The major components of the extract were identified as caffeoylquinic acid derivatives and the flavonoid rutin.

Conclusions

The data presented herein show local and systemic anti-inflammatory effects of the hydroalcoholic extract of aerial parts of Solidago chilensis, and implicate the inhibition of leukocyte–endothelial interactions as an important mechanism of the extract's action.     

Effects of acute administration of the hydroalcoholic extract of mate tea leaves (Ilex paraguariensis) in animal models of learning and memory

Aim of the study

Ilex paraguariensis St. Hilaire (Aquifoliaceae) is a plant widely cultivated in South America that is used to prepare a tea-like beverage with a reputation to improve cognitive function, a response that has been attributed to the constituents of the leaves, especially caffeine. Our previous study indicated that the hydroalcoholic extract of Ilex paraguariensis presents an antiparkinsonian profile in reserpine- and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-treated rodents.

Materials and methods

In the present study, the effects of the hydroalcoholic extract of Ilex paraguariensis on the short- and long-term learning and memory of rats were assessed with the social recognition, Morris water maze, and step-down inhibitory avoidance tasks.

Results

A preliminary HPLC fingerprint of the plant extract confirmed the presence of caffeine (the major compound), rutin and kaemperol, and revealed the absence of detectable concentrations of caffeic acid, quercetin and ursolic acid. Acute pre-training intraperitoneal (i.p.) or oral administration of the extract of Ilex paraguariensis improved the short-term social memory in a specific manner as well as facilitated the step-down inhibitory avoidance short-term memory evaluated 1.5 h after training. Moreover, a synergistic response was observed following the co-administration of ‘non-effective’ doses of caffeine and Ilex paraguariensis in the social memory. In contrast, pre-training administration of hydroalcoholic extract of Ilex paraguariensis did not alter the step-down inhibitory avoidance long-term memory evaluated 24 h after training, while the highest dose tested (250 mg/kg, i.p.) disrupted the animals’ performance in a cued version of the Morris water maze.

Conclusion

These results partly substantiate the traditional use of mate tea for improvement of cognition indicating that acute administration of hydroalcoholic extract of Ilex paraguariensis differentially modulates short- and long-term learning and memory in rats probably through its antagonist's action on adenosine receptors.     

The inhibitory activity of atractylenolide Ш, a sesquiterpenoid,on IgE-mediated mast cell activation and passive cutaneous anaphylaxis (PCA)

Ethnopharmacological relevance

AT Ш, a sesquiterpenoid, is the major component of Atractylodes japonica Koidz that has been used as a traditional oriental medicine.

Aim of the study

We investigated the anti-allergic activity of AT Ш and its mechanism of action.

Materials and methods

The released amount of β-hexosaminidase in mast cells, a key parameter of degranulation, was measured. Anti-allergic potential of AT Ш was evaluated using passive cutaneous anaphylaxis in vivo. The anti-allergic mechanism of AT Ш was investigated by immunoblotting analysis, RT-PCR and measurement of [Ca²⁺]i in mast cells.

Results

AT Ш significantly inhibited IgE/Ag-mediated degranulation with an IC₅₀ value (36±4 μM) in RBL-2H3 cells without affecting cell viability. It also suppressed IgE/Ag-mediated passive cutaneous anaphylaxis (PCA) response with an ED₅₀ value (65±41 mg/kg) in vivo. AT Ш suppressed the production of interleukin (IL-4) and tumor necrosis factor (TNF)-alpha mRNAs more potent than the Src-family kinase inhibitor PP2 in RBL-2H3 cells at all concentrations. In order to elucidate the anti-allergic mechanisms of AT Ш in mast cells, we examined the activated levels of signaling molecules. AT Ш inhibited the phosphorylation of Lyn, Fyn, Syk, LAT, PLCγ, Gab2, Akt, p38, and JNK kinases expression. IgE/Ag-mediated [Ca²⁺]i elevation was significantly inhibited by AT Ш.

Conclusions

Our study suggests that AT Ш might be used as a therapeutic agent for allergic diseases.     

Old plants newly discovered: Cassia sieberiana D.C. and Cassia abbreviata Oliv. Oliv. root extracts inhibit in vitro HIV-1c replication in peripheral blood mononuclear cells (PBMCs) by different modes of action

Ethnopharmacological relevance

Despite advances in anti-retroviral therapy which has transformed HIV/AIDS from a fatal to a manageable chronic disease, increasing viral drug resistance, side effects and uneven access to anti-retroviral drugs remain considerable therapeutic challenges. Partly as a consequence of these shortcomings and partly based on the fact that HIV/AIDS gives rise to opportunistic infections whose symptoms have been managed in Africa in an HIV/AIDS-independent context by traditional healers for centuries, many HIV/AIDS patients use herbal medicines. The aim of this study was to screen selected medicinal plants from Botswana, used by traditional healers to treat/manage HIV/AIDS, for inhibitory activities on HIV replication.

Materials and methods

Based on an ethnomedical survey, ethanolic tannin-containing and tannin-free extracts from 10 medicinal plants were tested for inhibitory properties against a clone of HIV-1c (MJ₄) measuring cytopathic effect protection and levels of viral p24 antigen in infected PBMCs.

Results

Cassia sieberiana D.C., Cassia abbreviata Oliv. Oliv. and Plumbago zeylanica L. extracts showed significant inhibition of HIV-1c (MJ₄) replication. The inhibitory activity of the Plumbago zeylanica extract could be attributed to its tannin content. Anti-HIV activity of Cassia sieberiana root and bark extracts, and Cassia abbreviata root extracts occurred in a concentration-dependent manner with an effective concentration (EC₅₀) of 65.1 μg/ml, 85.3 μg/ml and 102.8 μg/ml, respectively. Experiments to elucidate possible mechanism(s) of action revealed that Cassia sieberiana root and bark extracts blocked HIV replication at its binding- (EC₅₀ = 70.2 μg/ml and 90.8 μg/ml, respectively) and entry stage (EC₅₀ = 88.9 μg/ml and 100.5 μg/ml, respectively) while Cassia abbreviata extracts did not.

Conclusions

We report here for the first time a direct inhibitory effect on HIV-1c replication of extracts from two extremely popular medicinal plants, Cassia sieberiana and Cassia abbreviata. Considering the traditional uses of both Cassia species, our findings strongly suggest pilot clinical observational studies involving traditional healers to further evaluate the therapeutic potential of the Cassia extracts.     

A report on anti-oedemogenic activity of Byttneria herbacea roots--possible involvement of histamine receptor (type I)

Ethnopharmacological relevance

The traditional healers of the Kol tribes of West Bengal, Bihar and Jharkhand (India), widely use the woody rootstock of Byttneria herbacea to reduce the swelling of limbs, due to filariasis. Besides filariasis different part of this plant is used for the treatment of cholera, diarrhoea and asthma.

Aim of this study

This study is a preliminary attempt to evaluate the anti-oedemogenic activity of the roots of Byttneria herbacea.

Materials and methods

The anti-oedemogenic activity of the hydroalcoholic extract of the roots of Byttneria herbacea (HBH) was evaluated against carrageenan and histamine induced rat paw oedema, acetic acid induced writhing and histamine induced vascular permeability in mice. Further, the effect of HBH on the expression of human histamine receptor type I (H1R) was studied in HeLa cells.

Results

HBH exhibited significant dose-dependent inhibition (*p < 0.05) against carrageenan and histamine induced rat paw oedema. Similar significant dose-dependent inhibition was observed against acetic acid induced writhing and histamine-induced vascular permeability in mice. Moreover, H1R specific mRNA expression was also significantly (*p < 0.05) suppressed by HBH.

Conclusion

HBH was observed to possess anti-oedemogenic activity which is probably mediated through suppression of H1R.     

Hyperpigmentant activity of leaves and flowers extracts of Pyrostegia venusta on murine B16F10 melanoma

Ethnopharmacological relevance

Pyrostegia venusta is a native Brazilian plant which has a variety of uses in traditional folk medicine including the treatment of vitiligo. However, its effectiveness on melanogenesis is not yet elucidated.

Aim of the study

This study aimed to investigate the melanogenic activity of hydroalcoholic extracts from the leaves and flowers of P. venusta on murine B16F10 melanoma cells.

Materials and methods

Different concentrations of the hydroalcoholic extracts of flowers and leaves of P. venusta were evaluated in trials of spontaneous melanin content (4 days), and cell viability by the MTT assay in murine B16F10 cells, and in the mushroom tyrosinase activity in vitro.

Results

Both extracts, leaves (0.1; 0.3; 1 and 3 μg/mL) and flowers (0.03 and 0.1 μg/mL) increased the melanin content in a concentration dependent manner after 4 days of incubation on melanoma cells. Leaves extract promoted enhancement of melanogenesis with maximum effect of 33.3 ± 3% (3 μg/mL), and the flower extract increased in 23.4 ± 3% (0.1 μg/mL). The cell viability test using MTT showed that in the same tested concentrations of both extracts no cell death was detected. Actually, either extract was not able to cause any change in the tyrosinase activity. HPLC analysis of P. venusta extracts found 0.09% and 1.08% of allantoin on leaves and flowers extracts, respectively.

Conclusions

The leaves and flowers extracts of P. venusta stimulates B16F10 melanogenesis at very low concentrations. These findings support the folk medicinal use of P. venusta on the treatment of hypopigmentation diseases, such as vitiligo.     

Anti-allergic and anti-inflammatory effects of bakkenolide B isolated from Petasites japonicus leaves

Aims of the study

To elucidate the anti-allergic and anti-inflammatory effects of Petasites genus, we studied the effects of several compounds isolated from Petasites japonicas leaves.

Materials and methods

Bakkenolide B was isolated from Petasites japonicus leaves. Antigen-induced degranulation was measured in RBL-2H3 mast cells by measuring β-hexosamidase activity. Induction of inducible nitric oxide synthase and cyclooxygenase 2 was measured by Western blotting in peritoneal macrophages. Ovalbumin-induced asthma model was used for in vivo efficacy test of bakkanolide B.

Results

We found that bakkenolide B, a major component of the leaves, concentration-dependently inhibited RBL-2H3 mast cell degranulation. Bakkenolide B also inhibited the gene inductions of inducible nitric oxide synthase and cyclooxygenase 2 in mouse peritoneal macrophages. Furthermore, in an ovalbumin-induced asthma model, bakkenolide B strongly inhibited the accumulation of eosinophils, macrophages, and lymphocytes to bronchoalveolar lavage fluid.

Conclusion

Bakkenolide B has suppressive properties for allergic and inflammatory responses and may be utilized as a potent agent for the treatment of asthma.     

Hancornia speciosa: indications of gastroprotective, healing and anti-Helicobacter pylori actions

Ethnopharmacological relevance

Mangaba (Hancornia speciosa Gomez) is a medicinal plant frequently cited in ethnopharmacological inventories of the central region of Brazil against gastrointestinal disorders such as diarrhoea, ulcer, gastritis and stomachache.

Aim of the study

The hydroalcoholic extract (HE) and infusion (BI) of Hancornia speciosa bark were investigated for their ability to prevent and heal rodent gastric ulcer.

Materials and methods

The preventive and healing action of both preparations of Hancornia speciosa were evaluated in experimental models in rodents that simulated this disease in human gastric mucosa.

Results

BI did not exert gastroprotective effect, in contrast to HE (500 mg/kg, p.o.) that decreased (p < 0.05) the severity of gastric damage induced by HCl/ethanol (52%), indomethacin/bethanechol (51%), stress (52%) or pylorus ligature experiments (54%). HE increased (p < 0.05) the pH and decreased acid output of gastric juice. This extract promoted increase of mucus amount (3.62 mg/wt. tissue vs. 5.81 mg/wt. tissue), healing action (67%) and displayed anti-Helicobacter pylori effect.

Conclusions

The antiulcer action of Hancornia speciosa resulted in increase of gastric mucus formation and antioxidant properties of polymeric proanthocyanidins present in the bark composition of this medicinal plant.     

Evaluation of antiallergic and anti-anaphylactic activity of ethanolic extract of Sanseveiria trifasciata leaves (EEST) in rodents

Aim of the study

The leaves and rhizomes of Sansevieria trifasciata are used in folk medicine for treating bronchitis, asthma, cough, snake bite and insect bite etc. The ethanolic extract elicited analgesic, anti-inflammatory and antipyretic activity. Hence, it was decided to study the antiallergic activity of ethanolic extract of S. trifasciata (EEST) on various animal models as well as in vitro conditions, and also to understand possible mechanism of action.

Materials and methods

Ethanolic extract of S. trifasciata leaves (EEST) were prepared by cold maceration followed by concentration and evaporation under reduced pressure on a rotary evaporator to obtain semisolid mass. The various phytoconstituents were analyzed. The acute toxicity study of EEST was carried out in mice. The antiallergic and anaphylactic activities were evaluated using animal models viz. milk induced eosinophilia and leukocytosis, compound 48/80 induced mast cell degranulation, active and passive cutaneous anaphylaxis and histamine induced pedal edema. In addition, EEST effect on Shultz–Dale reaction in sensitized guinea pig ileum in ex vivo and antioxidant activity by free radical scavenging by DPPH method (in vitro) were also studied.

Results

EEST treatment at 100 mg/kg and 200 mg/kg p.o inhibited (a) milk-induced increased eosinophilia, leukocytosis, monocytes and neutrophils. (b) Prevented passive cutaneous and active anaphylactoid reactions. (c) Prevented compound 48/80 induced degranulation of sensitized mesenteric mast cells. (d) Inhibited histamine induced pedal edema formation significantly. EEST pretreatment inhibited Shultz–Dale reaction in guinea pig ileum and also elicited potent antioxidant activity.

Conclusion

Experimental findings demonstrate promising antiallergic and anti-anaphylactic activity of EEST and also elicited potent antioxidant activity. The antiallergic and anti-anphylactic activity might be due to inhibition of release of chemical mediators from mast cells largely by phytoconstituents like steroidal saponins, triterpenoids and flavonoids present in EEST.     

Effect of Sophora flavescens Aiton extract on degranulation of mast cells and contact dermatitis induced by dinitrofluorobenzene in mice

Ethnopharmacological relevance

The dried root of Sophora flavescens Aiton (Sophorae radix, SR) has long been used in traditional medicine for the treatment of fever and swelling in eastern countries.

Materials and methods

The present study investigated the anti-allergic and anti-inflammatory effects of SR using 1-fluoro-2,4-dinitrofluorobenzene (DNFB)-induced contact dermatitis mouse model and in vitro using RBL-2H3 cells.

Results

In mice, the topical application of 10 mg/mL of SR effectively inhibited enlargement of ear thickness and weight induced by repeated painting with DNFB. Topical application of SR also inhibited hyperplasia, edema, spongiosis and infiltration of mononuclear cells in ear tissue. In addition, production levels of interferon-gamma and tumor necrosis factor-alpha were decreased by SR in vivo. Finally, the release of histamine and β-hexosaminidase, and migration were inhibited by treatment with SR.

Conclusions

These data indicate the potential of SR in treating patients with allergic skin diseases and also suggest that related mechanisms are involved in anti-inflammatory action on the Th 1 skewing reaction and inhibition against recruitment and degranulation of mast cells.     

Anti-mycobacterial diynes from the Canadian medicinal plant Aralia nudicaulis

Ethnopharmacological relevance

Aralia nudicaulis, or wild sarsaparilla, is used as a traditional medicinal plant for the treatment of various illnesses by many of the Canadian First Nations. Iroquois and Algonquin First Nations of Eastern Canada use a tea prepared from dried Aralia nudicaulis rhizome as a cough medicine and for the treatment of tuberculosis. Previous investigations of aqueous extracts of Aralia nudicaulis rhizomes have shown it to possess antimycobacterial activity.

Aim of the study

To isolate and identify antimycobacterial constituents from Aralia nudicaulis rhizomes.

Materials and methods

Methanolic extracts of Aralia nudicaulis rhizomes were subjected to bioassay guided fractionation using the microplate resazurin assay (MRA) to assess inhibitory activity against Mycobacterium tuberculosis strain H37Ra. The antimycobacterial constituents were identified by NMR, MS and polarimetry.

Results

Two C17 polyacetylenes with significant antimycobacterial activity were isolated from the Aralia nudicaulis rhizome extract. The polyacetylenes were identified as (3R)-falcarinol and (3R, 9R, 10S)-panaxydol. Falcarinol and panaxydol displayed MICs of 25.6 μM and 36.0 μM and IC₅₀s of 15.3 μM and 23.5 μM against Mycobacterium tuberculosis H37Ra.

Conclusions

Falcarinol and panaxydol were identified as the principal constituents responsible for the antimycobacterial activity of Aralia nudicaulis rhizomes validating an ethnopharmacological use of this plant by the Canadian First Nations.     

Forsythia suspensa extract alleviates hypersensitivity induced by soybean β-conglycinin in weaned piglets

Aim of the study

Soybeans are known to stimulate food allergies; however, current therapies are lacking in alleviating hypersensitivity. The present study investigated whether Forsythia suspensa extract could attenuate purified soybean β-conglycinin-induced anaphylactic reactions in weaned piglets.

Materials and methods

Eighteen 14-day-old piglets were sensitized and boosted by oral administration of purified β-conglycinin. Forsythia suspensa extract was supplemented in the diet after the initial sensitization and continued for the remainder of the experiment. Piglets were challenged on day 28, and anaphylactic symptoms, passive cutaneous anaphylaxis, plasma histamine and intestinal microbial flora were analyzed. T-cell proliferative responses and cytokine production were also determined.

Results

Forsythia suspensa extract alleviated β-conglycinin-induced anaphylactic symptoms by markedly reducing anaphylactic antibodies, mast cell degranulation, and histamine release while improving intestinal microbial flora. Furthermore, Forsythia suspensa extract significantly suppressed β-conglycinin-induced T lymphocyte proliferation and IL-4 synthesis.

Conclusion

Forsythia suspensa extract protected β-conglycinin-sensitized piglets from anaphylactic reactions. Forsythia suspensa extract may provide a novel effective therapy for soybean allergy.     

Aqueous extract of Centella asiatica promotes corneal epithelium wound healing in vitro

Ethnopharmacological relevance

Centella asiatica is a traditional herbal medicine that has been shown to have pharmacological effect on skin wound healing, and could be potential therapeutic agent for corneal epithelial wound healing.

Aim of the study

This study was done to evaluate the effects of Centella asiatica on the proliferation and migration of rabbit corneal epithelial (RCE) cells in the in vitro wound healing model.

Materials and methods

RCE cells were cultured with or without supplementation of Centella asiatica aqueous extract. Viability and proliferation of the RCE cells was determined by MTT assay and cell cycle was analyzed by flow cytometry. In vitro re-epithelization was studied by scratch assay and migration rate was evaluated quantitatively by image analyzer. Expression of corneal specific differentiation markers, CK12 and connexin 43, were studied via RT-PCR.

Results

It was found that supplementation of Centella asiatica did not show any significant effect on the RCE cells proliferation at the concentration up to 500 ppm, while at the concentration of 1000 ppm significantly inhibited RCE cells proliferation (p < 0.05). However, at the concentration up to 62.5 ppm, RCE cells shows significant enhancement of migration rate compared to the control group (p < 0.05). It was also found that the supplementation of Centella asiatica aqueous extract did not alter the expression of differentiation markers and cell cycle.

Conclusion

In conclusion, supplementation of Centella asiatica aqueous extract at low concentrations could be useful to promote corneal epithelium wound healing.