Korean red ginseng extract ameliorates skin lesions in NC/Nga mice: an atopic dermatitis model

Aim of the study

Korean red ginseng (KRG, Panax ginseng C.A. Meyer) has traditionally been considered to harbor anti-allergic effects, however its action on atopic dermatitis (AD) is unclear. Therefore, we investigated the effect of KRG on AD using NC/Nga mice as an AD model. In addition, we examined the effect of aprepitant (substance P specific neurokinin receptor antagonist) on AD.

Materials and methods

The KRG extract and aprepitant were administered orally to NC/Nga mice. The efficacy of KRG and aprepitant was evaluated by assessing total clinical severity score, ear thickness, serum IgE level and histology. In addition, mRNA and protein expression were measured by real-time RT-PCR and immunohistochemistry, respectively.

Results

The KRG extract significantly reduced the total clinical severity score, ear thickness and the level of serum IgE in AD mouse model, whereas aprepitant reduced only the serum IgE level. KRG not only decreased TNF-α, IFN-γ and substance P but also reduced the infiltration of FOXP3+ regulatory T (Treg) cells and CD1a+ Langerhans cells in the lesions, whereas aprepitant decreased only substance P and the infiltration of Treg cells.

Conclusion

These results suggest that KRG extract may be a potential therapeutic modality for AD and aprepitant could be used as adjunctive agent to control pruritus in AD.     

Effects of Catalpa ovata stem bark on atopic dermatitis-like skin lesions in NC/Nga mice

Ethnopharmacological relevance

The stem bark of Catalpa ovata has been used as a traditional herbal medicine for the treatment of various inflammatory diseases such as itching and scabies.

Aim of the study

In the present study, we investigated the anti-AD effects of Catalpa ovata stem bark on Dermatophagoides farinae-induced AD in a NC/Nga mouse AD model. We determined dermatitis score, histology, IgE, cytokines, and chemokines related to hypersensitive immune responses in AD. The mechanism of action was also investigated using HaCaT cells.

Materials and methods

We investigated the topical effects of Catalpa ovata stem bark on AD-like skin lesions in NC/Nga mice. Five category-experiments were performed, including assessment of dermatitis score; histological analysis of dorsal skin lesions; quantitative measurement of serum total IgE; quantitative measurement of cytokines (IL-1β, IL-4, IL-5, IL-6, IL-13, TNF-α) from dorsal tissue; and RT-PCR analysis of for TSLP and TARC mRNA expression in HaCaT cells.

Results

The clinical dermatitis score was significantly lower in Catalpa ovata extract (COE) groups than in the control group. Histological analysis showed that COE inhibited hypertrophy and hyperkeratosis of the epidermis, intracellular edema, and reduced the infiltration of inflammatory cells. COE significantly inhibited serum total IgE; Th2 cytokines IL-4, IL-5 and IL-13; pro-inflammatory cytokines IL-1β, IL6 and TNF-α; the Th2 chemokine TARC and the pro-Th2 cytokine TSLP.

Conclusion

These results demonstrate that Catalpa ovata stem bark may be a useful external medicine for treatment of AD. Further investigation is necessary to determine appropriate COE dosage and to evaluate the safety of this medicinal herb.     

Oral administration of Uncariae rhynchophylla inhibits the development of DNFB-induced atopic dermatitis-like skin lesions via IFN-γ down-regulation in NC/Nga mice

Ethnopharmacological relevance

Uncariae rhynchophylla (UR) is an herb which has blood pressure lowering and anti-inflammatory effects and has been prescribed traditionally to treat stroke and vascular dementia.

Aim of study

In the present study, we examined whether UR suppress Atopic dermatitis (AD)-like skin lesions in NC/Nga mice treated with 2, 4-dinitrofluorobenzene (DNFB) under SPF conditions.

Material and methods

The effect of UR in DNFB- treated NC/Nga mice was determined by measuring the skin symptom severity, levels of serum IgE, and of the amounts of IL-4 and IFN-γ secreted by activated T cells in draining lymph nodes.

Results

Oral administration of UR to DNFB-treated NC/Nga mice was found to inhibit ear thickness increases and the skin lesions induced by DNFB. IFN-γ production by CD4+ T cells from the lymph nodes of DNFB-treated NC/Nga mice was significantly inhibited by UR treatment, although levels of IL-4 and total IgE in serum were not.

Conclusion

UR may suppress the development of AD-like dermatitis in DNFB-treated NC/Nga mice by reducing IFN-γ production.     

Inhibitory effects of Chelidonium majus extract on atopic dermatitis-like skin lesions in NC/Nga mice

Aim of the study

Chelidonium majus (CM) has traditionally been used for treatment of various inflammatory diseases including atopic dermatitis (AD). However its action on atopic dermatitis (AD) is unclear. Therefore, we investigated the effect of CM on AD using NC/Nga mice as an AD model.

Materials and methods

The effect of CM on 1-chloro-2,4-dinitrobenzene (DNCB) induced NC/Nga mice was evaluated by examining skin symptom severity, itching behavior, ear thickness, levels of serum immunoglobulin E (IgE), tumor necrosis factor-α (TNF-α), and interlukin-4 (IL-4), skin histology.

Results

The CM significantly reduced the total clinical severity score, itching behavior, ear thickness and the level of serum IgE in AD mouse model. CM not only decreased TNF-α but also IL-4.

Conclusion

These results suggest that CM may be a potential therapeutic modality for AD.     

Korean red ginseng (Panax ginseng) ameliorates type 1 diabetes and restores immune cell compartments

Ethnopharmacological relevance

Historical records reveal that in traditional medicine, a disease similar to diabetes was treated with ginseng. Korean red ginseng has been considered beneficial as a dietary supplement for its anti-diabetic potential.

Aim

This study was designed to investigate the prophylactic potential of Korean red ginseng (KRG) extract (Panax ginseng C.A. Meyer Radix Rubra) in a well-established mouse model of Type 1 diabetes (T1D).

Materials and methods

The prophylactic effect of KRG extract was evaluated in mice fed with KRG extract for two weeks prior to induction of diabetes by streptozotocin (STZ) administration. Glucose levels and glucose challenge test results of KRG-treated diabetic mice were compared to those of untreated diabetic mice and healthy control mice. Examination of the immune compartments in lymphoid organs and immunohistochemical staining of pancreas for islet cell morphology and insulin producing beta cells were performed.

Results

KRG extract significantly lowered blood glucose levels to an average of 250 mg/dl from 350 mg/dl and improved glucose challenge testing when applied as prophylaxis. Histological findings indicated that KRG extract protected against STZ-induced destruction of pancreatic tissue and restored insulin secretion. Strikingly, this effect was accompanied by restoration of lymphocytes in secondary lymphoid organs, suggesting that KRG extract facilitated immune homeostasis.

Conclusion

This is the first report to demonstrate the prophylactic function of KRG extract in ameliorating the hyperglycemia of T1D. Immune compartments of diabetic mice were found to be preserved in KRG-treated mice suggesting that Korean red ginseng may benefit T1D patients, not only for its hypoglycemic but also for its immunomodulatory effects.     

Inhibitory effects of Drynaria fortunei extract on house dust mite antigen-induced atopic dermatitis in NC/Nga mice

Ethnopharmacological relevance

Drynaria fortunei (Kunze) J. Sm has been widely used in traditional medicine for the treatment of inflammation, hyperlipidemia, arteriosclerosis, rheumatism, and bone healing. We investigated the anti-inflammatory effects of a 70% ethanol extract of Drynaria fortunei (DFE).

Materials and methods

We evaluated the anti-inflammatory effects of topically applied DFE on house dust mite Dermatophargoides farinae-induced atopic dermatitis-like skin lesions in NC/Nga mice.

Results

Treatment of NC/Nga mice with DFE reduced the dermatitis score, ear thickness, and serum levels of IgE, IgG1, and IL-6. Histopathological analyses of ear and skin lesions showed inhibition of the thickening of the epidermis and reduced epidermal/dermal infiltration of inflammatory cells. In ear lesions, mRNA expression levels of IL-4, IL-6, and tumor necrosis factor-α were reduced by DFE treatment.

Conclusions

DFE inhibited the development of dermatitis-like skin lesions in NC/Nga mice. These results suggest that DFE may be a therapeutic candidate for the treatment of AD.     

Korean red ginseng stimulates insulin release from isolated rat pancreatic islets

Ethnopharmacological relevance

Korean red ginseng (KRG), one of heat-processed Korean ginseng (Panax ginseng C.A. Meyer), has a long history as herbal remedy for antidiabetic effect.

Aim of the study

The effect and mechanism of KRG on stimulation of insulin release were investigated in isolated rat pancreatic islets.

Material and methods

Pancreatic islets isolated from rats were used to evaluate the insulinotropic action of KRG. The effect of Ca on the insulinotropic action of KRG was investigated.

Results

The aqueous ethanolic extract of KRG (AEE-KRG) (0.1–1.0 mg/ml) significantly evoked a stimulation of insulin release at 3.3 mM glucose compared to the control. Experiments at different glucose concentrations (8.4 and 16.7 mM) showed that AEE-KRG significantly stimulated on its own whereas it did not potentiate insulin secretion induced by glucose. The extracellular Ca²⁺-free condition, a L-type Ca²⁺ channel blocker and an ATP-sensitive K⁺ channel opener significantly inhibited insulin secretion evoked by AEE-KRG.

Conclusion

These findings suggest that KRG displays beneficial effects in the treatment of diabetes at least in part via the stimulation of insulin release in a glucose-independent manner.     

Effects of Bambusae caulis in Liquamen on the development of atopic dermatitis-like skin lesions in hairless mice

Ethnopharmacological relevance

Bambusae caulis in Liquamen (BCL) is a nutritious liquid extracted from heat-treated fresh bamboo stems. It is an important traditional herbal medicine used to treat coughs and asthma in East Asia. In recent years, it has been studied for its anti-inflammatory, anti-allergenic, and immune-regulating properties.

Aim of the study

To examine whether BCL suppresses the development of 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)-like skin lesions in hairless mice.

Materials and methods

The effects of BCL were analyzed by measuring transepidermal water loss (TEWL), melanin content, and erythema in the skin, leukocyte numbers and IgE levels in the serum, and mRNA expression of relevant cytokines in the spleen.

Results

The transdermal administration of BCL to hairless mice inhibited the development of DNCB-induced AD-like skin lesions by suppressing TEWL, melanin production and erythema of skin, the number of leukocytes and the level of IgE in serum, and the mRNA expression of IL-4, IL-13, and TNF-α in the spleen. However, BCL administration increased the expression of IFN-γ in the spleen.

Conclusions

These findings indicate that BCL suppresses the development of DNCB-induced AD-like skin lesions in hairless mice, suggesting that BCL may be a potential therapeutic agent for AD in a clinical setting.     

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.     

Indirubin,a purple 3,2- bisindole,inhibited allergic contact dermatitis via regulating T helper (Th)-mediated immune system in DNCB-induced model

Ethnopharmacological relevance

Indirubin, isolated from Indigo naturalis (Apiaceae) is a purple 3,2- bisindole and a stable isomer of indigo. Although it is known to have anti-inflammatory activities, its mechanism of action has not been elucidated.

Materials and methods

Seven-week-old female BALB/c mice were sensitized with 1-chloro-2,4-dinitrobenzene (DNCB) to induce skin inflammation. Hematoxylin and eosin staining was performed to assess epidermal and dermal hyperplasia, which were determined by measuring the thicknesses of the epidermis and dermis, respectively. We also evaluated serum immunoglobulin E (IgE) levels and cytokines production, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, 6 and Interferon (IFN)-gamma. In addition, we investigated nuclear factor (NF)-κB, IκB-α and mitogen-activated protein (MAP) kinase activities for verifying the molecular mechanism of inflammation.

Results

Indirubin treatment suppressed skin inflammation in DNCB-exposed mice. The skin lesions were significantly thinner in the Indirubin-treated group than in untreated controls, and the hyperkeratosis disappeared. Indirubin reduced the total serum IgE level and cytokines production. In addition, it normalized NF-κB, IκB-α and MAP kinase expression.

Conclusions

Indirubin might be a useful treatment for allergic contact dermatitis via regulating the co-expression of T helper (Th) 1 and 2 cell-mediated immune responses.     

Preventive effects of skullcap (Scutellaria baicalensis) extract in a mouse model of food allergy

Ethnopharmacological relevance

Food allergy, which accompanies acute symptoms such as pruritus, vomiting, diarrhea, and lethal anaphylactic shock is an increasing clinical problem. Skullcap (Scutellaria baicalensis Georgi) has been widely used as a traditional herbal medicine to treat inflammation, cancer, and allergy, but its effects in treating food allergy are not yet known.

Materials and methods

To examine the effect of skullcap on food allergy, female BALB/c mice were sensitized with 20 μg OVA and 2 mg alum by intraperitoneal injection on day 0. From day 17, mice were orally challenged with OVA (50 mg) in saline every 3 days, for a total of six times. To investigate the preventive effect, skullcap (25 mg/kg) was orally administered every day from day 17 to 34.

Results

Food allergy symptoms were evaluated by the criteria for diarrhea, anaphylactic response, and rectal temperature. Severe symptoms of food allergy were observed in the sham group (diarrhea, 3 points; anaphylactic response, 2.6 points; rectal temperature, −8.36 °C. In contrast, the skullcap treatment group had a significantly suppressed OVA-induced anaphylactic response (1.3 points) and rectal temperature (−4.76 °C). Moreover, both OVA-specific IgE, Th17 cytokine (IL-17), and Th2-related cytokines (IL-4, IL-5, IL-10, and IL-13), which increased with food allergy, were significantly inhibited by skullcap treatment.

Conclusion

We demonstrate that the administration of skullcap attenuates OVA-induced food allergy symptoms through regulating systemic immune responses of Th cells. These results indicate that skullcap may be a potential candidate as a preventive agent for food allergy.     

20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol-fortified ginseng extract attenuates the development of atopic dermatitis-like symptoms in NC/Nga mice

Ethnopharmacological relevance

Ginseng and ginsenosides are frequently used in the treatment of chronic inflammatory diseases. Recently, 20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol (GPD), the main metabolite of ginsenosides, was reported to have both anti-allergic and anti-pruritic effects. The immunomodulatory effects of GPD-fortified ginseng extract (GFGE) on atopic dermatitis (AD)-like symptoms in mice were investigated. This study was designed to investigate the preventive effect of GFGE on AD-like symptoms.

Materials and methods

The effects of orally administered GFGE on Dermatophagoides farinae body extract (DFE)-induced AD-like symptoms in NC/Nga mice were assessed by analyzing dermatitis score, ear thickness, scratching time, skin histological changes, and serum level of macrophage-derived chemokine (MDC). In addition, splenocytes were isolated from the mice and stimulated with anti-CD3 and anti-CD28 monoclonal antibodies to produce cytokines.

Results

Oral administration of GFGE significantly attenuated DFE-induced increases in dermatitis score, ear thickness, scratching time, and severity of skin lesions in NC/Nga mice. GFGE treatment also reduced level of MDC in serum, infiltration of eosinophils and mast cells in skin, and production of cytokines in splenocytes.

Conclusions

These results suggest that GFGE might ameliorate DFE-induced AD-like symptoms and be an alternative therapeutic agent for the prevention of AD.     

Regulation of signaling molecules associated with insulin action, insulin secretion and pancreatic β-cell mass in the hypoglycemic effects of Korean red ginseng in Goto-Kakizaki rats

Ethnopharmacological relevance

Korean red ginseng (KRG) has long history as herbal remedy for antidiabetic effect.

Aim of the study

To study molecular mechanisms by which KRG ameliorates diabetes mellitus, we investigated whether the supplementation with the aqueous extract of KRG as a dietary admixture (1%, w/w) regulates the expressions of signaling molecules that are associated with insulin action, insulin secretion and pancreatic β-cell mass in spontaneously diabetic Goto-Kakizaki (GK) rats.

Methods

An aqueous extract of KRG was supplemented for the estimated dosage to be 0.2 g/kg rat/day beginning at 5 weeks of age for 12 weeks in male GK rats. Plasma glucose levels were measured every 4 weeks. The expressions of signaling molecules that are associated with insulin action, insulin secretion and β-cell mass in tissues were determined by Western blotting.

Results

The 12-week supplementation with KRG significantly (P<0.05) decreased blood glucose compared to control. It up-regulated the expression of glucose transporter (GLUT) 4 in adipose tissue, and down-regulated the expression of protein tyrosine phosphatases (PTP)-1B in adipose tissue and skeletal muscle. It also up-regulated the expression of insulin and down-regulated the expression of uncoupling protein (UCP) 2, Bax and poly (ADP-ribose) polymerase (PARP) in pancreas.

Conclusions

These results suggest that GLUT4, PTP-1B, insulin, UCP2, Bax and PARP may be the primary targets of KRG that result in increase in insulin action and in insulin secretion, and decrease in β-cell mass, and that cause the normalization in glucose homeostasis.     

Inhibition of 2,4-dinitrofluorobenzene-induced atopic dermatitis by topical application of the butanol extract of Cordyceps bassiana in NC/Nga mice

Ethnopharmacological significance

The Cordyceps species are insect-borne mushrooms that have been ethnopharmacologically used for skin diseases such as eczema and dermatitis.

Aim of the study

In this study, we investigated the curative effects of the butanol fraction (CBBF) of Cordyceps bassiana on atopic dermatitis.

Materials and methods

Dermatitis was induced by repeated application of 2,4-dinitrofluorobenzene (DNFB) in NC/Nga mice. After a topical application of CBBF on the skin lesions, the dermatitis score, epidermal thickness, mast cell number, and interleukin (IL)-4 and interferon (IFN)-γ, as well as the levels of histamine and immunoglobulin E (IgE) in the serum, were measured. Moreover, effect of CBBF on histamine release was examined using RBL-2H3 under stimulation with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA).

Results

CBBF inhibited atopic dermatitis symptoms and signs in the DNFB-treated NC/Nga mice. The suppressive activity of topically applied CBBF may be due to the dose-dependent blockade of a series of immunopathological events, including the release of histamine, the production of IgE, and the secretion of IL-4 and IFN-γ. However, this extract did not directly suppress the degranulation process, assessed by measuring β-hexosaminidase release.

Conclusions

Our results suggest that CBBF can be applied as an effective herbal remedy to treat atopic dermatitis.     

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.     

Inhibitory effects of Cinnamomum cassia extract on atopic dermatitis-like skin lesions induced by mite antigen in NC/Nga mice

Aim of the study

: Cinnamomum cassia (C. cassia) has been traditionally used to treat allergic disease as well as dyspepsia, gastritis, and blood circulation disturbances. However, the antiallergic properties of C. cassia have not been fully verified using scientific tools. This study investigated the effectiveness of C. cassia extract (CCE) as an antiallergic agent in atopic dermatitis model and underlying mechanism.

Materials and methods

: The effect of CCE on mite antigen-treated NC/Nga mice was evaluated by examining skin symptom severity, levels of serum IgE, tumor necrosis factor-α (TNF-α), and histamine, skin histology, and mRNA expression of cytokines in the skin lesions. Moreover, the effect of CCE on TNF-α-and interferon-γ (IFN-γ)-induced chemokine production in human keratinocytes was investigated using ELISA.

Results

: CCE treatment of NC/Nga mice reduced the dermatitis score and the levels of serum IgE, histamine, and TNF-α. Histological examination showed inhibition of the thickening of the epidermis/dermis and reduced dermal infiltration of inflammatory cells. In skin lesions, mRNA expression of IL-4, TNF-α, and thymus and activation-regulated chemokine (TARC) was inhibited by CCE treatment. The production of TARC, macrophage-derived chemokine, and RANTES from IFN-γ-and TNF-α-stimulated human keratinocytes was suppressed by CCE treatment in a dose-dependent manner.

Conclusions

: CCE inhibits the development of atopic dermatitis-like skin lesions in NC/Nga mice by suppressing the T-helper 2 cell response.