Guinea Pig Tracheal Chains Research Articles

Antiasthmatic Efficacy Of Ethanolic Leaf Extract Of Fagonia Arabica Linn On Isolated Guinea Pig Tracheal Chain Preparation

Antiasthmatic Efficacy Of Ethanolic Leaf Extract Of Fagonia Arabica Linn On Isolated Guinea Pig Tracheal Chain Preparation

EVALUATION OF ANTI-ASTHMATIC ACTIVITY OF ETHANOLIC EXTRACT OF CYNODON DACTYLON LEAVES

In the present study Cynodon dactylon leaves ethanolic extract and its chloroform and ethyl acetate fractions were used to evaluate the anti-asthmatic activity, using various experimental in vivo and in vitro animal models. Ethanolic extract of Cynodon dactylon and its chloroform and ethyl acetate fractions were evaluated for its anti-asthmatic activity by in vitro models (isolated guinea pig ileum preparation and isolated guinea pig tracheal chain preparation) in vivo models (Histamine and acetylcholine induced bronchospasm in guinea pigs and milk induced eosinophilia in mice model). Ethanolic extract of Cynodon dactylon and its ethyl acetate fraction at the concentration of 10 mg significantly antagonized the effect of histamine induced contraction on isolated guinea pig ileum preparation. Ethyl acetate fraction of Cynodon dactylon showed the maximum spasmolytic activity and significantly extended the latent period of convulsion as compared to standard (Ketotifen fumarate) upon histamine and acetylcholine exposure in a dose dependent manner. The study concluded that, chloroform and ethyl acetate fractions of Cynadon dactylon was shown significant anti-asthmatic activity.

Effect of Roflumilast in airways disorders via dual inhibition of phosphodiesterase and Ca2+-channel

The bronchodilator effects of Roflumilast “a selective phosphodiesterase type-4 (PDE4)” inhibitor studied in this experimental protocol. The spiral strips of isolated guinea-pig tracheal chains mounted in organ bath and maintained in Krebs solution ventilated with carbogen at 32 °C and in Ca++ restricted krebs solution. PDE inhibitory activity was evaluated by recording dose response curves using inhibitory effect of isoprenaline on CCh induced contractions. For confirmation of PDE inhibition the intracellular cAMP levels were also estimated. Roflumilast resulted a sharp inhibition in contractile responses of carbachol (CCh, 1 µM) and K+ (80 mM) and the results were almost similar to verapamil. In Ca++ restricted Krebs solution, a rightward shift in the Ca++ response curves observed in the tracheal chain strips which were pretreated with Roflumilast (0.001–0.003 mg/mL) and the maximum response was suppressed, similarly as with verapamil. PDE inhibitory effect of Roflumilast evaluated by recording dose-dependent (0.03–0.1 mg/mL) responses, the isoprenaline-induced inhibitory dose response curves shifted leftward similar to papaverine (PDE inhibitor). Pretreatment with Roflumilast exhibited elevated intracellular cAMP levels in tracheal strips. Findings of the experiment conclude bronchodilatory influence of Roflumilast via PDE and Ca++ channel inhibition. Results of current experiment offers comprehensive mechanistic background of Roflumilast in future as therapeutic bronchodilator for hyperactive bronchial airway diseases.

Design, Synthesis, Biological Evaluation, and In Silico ADMET Studies of 1,8-Naphthyridine Derivatives as an H1-receptor Inhibitor

In the present study, 1,8-naphthyridine-3-carboxylic acid derivatives (5a1, 5a2, 5b1, and 5b2) were designed, synthesized, and screened for their in vitro H1-antihistaminic activity. H1R inhibitory activity of the synthesized derivatives was calculated by the modified Van Arman technique, histamine-induced bronchoconstriction in guinea pigs. A good bronchorelaxant effect of compounds was observed in histamine-contracted guinea pig tracheal chain through H1-receptor antagonism. In addition, the hypothetically resulted compounds are checked for their reliability on other in silico drug designing online web services like SwissADME predictor. In silico ADMET analysis results show that all the derivatives had negligible toxicity, good absorption, and solubility profile. These compounds may serve as possible lead for establishing safe and effective antihistaminic agent(s).

Anti-histaminic and bronchodilatory activities of aqueous and methanol extracts of <i>Calotropis procera</i> (Ait) R.Br. root bark on allergic asthma in rodents

The root bark of Calotropis procera (C. procera) (Asclepiadaceae) has been reported to be a part of herbal remedies for the management of allergic conditions including asthma. However, there is paucity of data on its anti-histaminic and bronhodilatory activity in asthma. This study therefore aimed to provide some pharmacological rationale for the ethnomedical use of C. procera as an anti-histamine and bronchodilator in asthma. The aqueous and methanol extracts of C. procera were investigated for anti-histaminic and bronchodilatory activities using histamine induced contraction of isolated guinea pig tracheal chain (at 0.5 ml, 1 ml and 2 ml, and stock concentration of 0.5 mg/ml), histamine induced contraction of isolated guinea pig ileum strip test (at 0.1, 0.2, 0.4, 0.8 and 1 ml, and stock concentration of 10 mg/ml), and haloperidol induced catalepsy test in rats (at 200 mg/kg and 300 mg/kg doses). Both extracts of C. procera significantly relaxed (p˂0.01) histamine induced contraction of isolated guinea pig trachea. The extracts also significantly inhibited (p˂0.001) histamine induced contraction of isolated guinea pig ileum. The aqueous extract did not significantly inhibit haloperidol-induced catalepsy. However, methanol extract significantly inhibited (p˂0.05) haloperidol-induced catalepsy at 300 mg/kg. The aqueous and methanol root bark extract of C. procera was found to poses anti-histaminic and bronchodilatory activities in in vivo and in vitro antiasthmatic test on animal models, with the methanol extract having greater activity than the aqueous extract, thus support the folkloric use of the plant in inflammatory and allergic conditions including asthma.Keywords: Calotropis procera, Anti-histaminic, Bronchorelaxant, Anti-asthmatic, Histamine

INHIBITORY EFFECT OF ETHANOLIC EXTRACT OF ERIOBOTRYA JAPONICA LEAVES PRE-INCUBATED WITH THEOPHYLLINE AND ASPIRIN ON ISOLATED GUINEA PIG TRACHEAL

Objectives: The objectives of the study were to examine the inhibitory effect of ethanol extract of Eriobotrya japonica leaves (EEEJL) pre-incubated with theophylline and aspirin on isolated guinea pig tracheal chains against acetylcholine (ACh)-induced contraction.Methods: The effect of EEEJL (1-8 mg/Ml) on the isolated tracheal strips was tested in vitro. Furthermore, the mechanism of relaxant effects of EEEJL was evaluated in the presence of theophylline and aspirin.Results: The contractile response evoked by Ach (1.25 × 10−3 M) was decreased by EEEJL (effective concentration50 = 1.36 mg/mL) and has no significant difference of relaxant effect to that of EEEJL pre-incubated with theophylline and aspirin (p>0.05).Conclusion: The EEEJL decreased the ACh-induced contraction through the inhibition of PDE and the protective effect on prostaglandin E2.

English

Guiera senegalensis is a medicinal plant that is widely used in West Africa against many illnesses. In this work, the antiasthmatic properties of ethanol leaf extract of the G. senegalensis were evaluated by using various in vitro animal models. In vitro models like isolated guinea pig tracheal chain preparation, isolated guinea pig ileum and rabbit jejunum preparations were studied to evaluate possible mechanism by which extract shows relaxant activity. The preliminary phytochemical screening of the extract revealed the presence of alkaloids, anthraquinones, flavonoids, saponins and tannins. The study showed that the extract contained phytochemicals such as flavonoids, alkaloids, steroids, tannins and saponins. Isolated tracheal smooth muscles contractions induced by histamine was significantly (p<0.01) reduced by the extract, so also that induced by acetylcholine at concentrations of 4 and 8 mg/ml. The findings were similar to that of 0.4 µg/ml isoprenaline. Guinea pig and rabbit jejunum contractions induced by histamine and acetylcholine were significantly (p<0.01) reduced by the extract. These observed effects can be attributed to the presence of phytochemicals such as flavonoids, alkaloids and steroids in the extract. The results of these studies indicated ethanol extract of G. senegalensis possess antiasthmatic activity. Key words: Antiasthmatic activity, bronchoconstriction, Guiera senegalensis, guinea pig ileum. &nbsp

Corilagin Attenuates Allergy and Anaphylactic Reaction by Inhibiting Degranulation of Mast Cells.

BackgroundThis study evaluated the anti-allergic activity of corilagin and also postulates the possible mechanism of its action.Material/MethodsCorilagin was given orally at dose of 10, 20, and 40 mg/kg/day. All the animals (guinea pigs, rats, and mice) were sensitized for allergy such as eosinophilia and leukocytosis induced by milk; degranulation of mast cell by compound 48/80; and passive and active anaphylaxis. Moreover, the antagonistic effect was determined by estimating the effect of corilagin on contraction of guinea pig tracheal chain and ileum induced by Ach and histamine, respectively.ResultThere was a significant decrease in the leukocyte and eosinophil counts in the corilagin-treated group compared to the negative control group. Treatment with corilagin significantly protects the degranulation of mast cells, and it also has significant anti-muscarinic and antihistaminic activity by reducing the muscle contraction induced by Acetylcholine (Ach) and histamine in guinea pig tracheal chain and ileum.ConclusionsCorilagin possess anti-anaphylactic and anti-allergic activity by inhibiting the release of mediators from mast cells and by decreasing the serum concentration of immunoglobulin E (IgE).

Evaluation of Antiasthmatic Activity of Murraya Koenigii L. Leaves

The present investigation was designed to evaluate the anti-asthmatic activity of ethanolic extract of Murraya Koenigii Leaves in experimental animals. Murraya Koenigii Leaves was evaluated for anti-histaminic activity using isolated Guinea pig tracheal chain preparation, histamine induced Bronchoconstriction in Guinea pig and milk induced leucocytosis in mice. Ethanolic extract of Murraya Koenigii Leaves oral dose 400mg/kg body weight significantly inhibited dose dependent contraction of Guinea pig tracheal chain produced by histamine and also showed significant protection by prolonging PreConvulsion Dyspnoea time (PCT) in guinea pigs. Murraya Koenigii Leaves was evaluated by milk induced leucocytosis in mice showed significant decreased of total leukocyte count. Thus, Murraya Koenigii Leaves showed anti-allergic activity against histamine hence possesses potential role in the treatment of asthma.

Bronchodilatory effect of <i>Myxopyrum serratulum</i> in animal model

<p class="Abstract">The plant <em>Myxopyrum </em>serratulum is traditionally claimed to relieve asthma and cough. The present study was undertaken to evaluate the bronchodilatory effect of the methanolic extract of <em>M. </em>serratulum on histamine-induced bronchospasm by <em>in vivo</em> and the inhibitory effect of the extract on histamine-contracted tracheal chain and ileum by <em>in vitro</em> guinea pig model. Additionally, the relaxant effect of four cumulative concentrations of the extract (0.25, 0.5, 0.7 and 1.0 g%) was assessed using precontracted tracheal chain under different conditions. The extract (400 mg/kg) prolonged the preconvulsive time to 102.3 ± 3.8 sec when compared to saline and standard chlorpheniramine maleate as 121.3 ± 4.5 sec (p<0.05). The extract also possessed significant inhibitory effect on histamine-contracted guinea pig ileum and tracheal chain and also exhibited significant relaxation effect on precontracted tracheal chain of guinea pig models contracted by 60 mM KCl (p<0.001) and 10 µM methacholine (p<0.001) when compared with standard theophylline.</p>

Evaluation of anti-histaminic and bronchodilatory Activity of milk of equus africanus Asinus in rodents

The Equus africanus asinus milk commonly known as donkey milk (DM) is often used as a substitute for breast milk, and as medicine for treating the child of delicate health, improving immunity, treatment of respiratory problems like cough, whooping cough and asthma in infants.The present study was therefore designed to evaluate the antihistaminic and bronchodilator activity of milk of Equus africanus asinus in rodents. Equus asinus milk was evaluated using histamine induced contractions on isolated ileum and tracheal chain preparations and histamine induced bronchoconstriction in Guinea pigs. The Equus asinus milk significantly inhibited histamine induced contraction of isolated guinea pig ileum and tracheal chain preparation and significantly protected the guinea pigs against histamine induced Bronchoconstriction as indicated by delay in the pre-convulsive dyspnoea time (PCT) following the exposure of histamine aerosol. The results suggested that Equus asinus milk has antihistaminic and bronchodilator activity and may prove beneficial effect in the management of asthma.

Design, Synthesis and Evaluation of New 2, 6-Dihydroimidazo[1, 2-c]Pyrimido[5, 4-e]-Pyrimidine-5(3H)-thiones as Possible Antihistaminic/Antiasthmatic Agents.

A series of new 10-(alkylamino)-8-methyl-2, 6-dihydroimidazo[1, 2-c]pyrimido[5, 4-e]pyrimidine-5(3H)-thiones (4a-g) were subjected to molecular property prediction (drug-likeness, lipophilicity and solubility parameters) using Osiris Property Explorer, ALOGPS 2.1, Molinspiration and ACD/Chemsketch 12.0 software programmes. The calculated drug-related properties of the designed molecules were similar to those found in most marketed drugs. Amongst the proposed analogues, four promising candidates were chosen (4a-d) for synthesis on the basis of Lipinski's 'Rule of Five' and drug-likeness scores. The significant biological activity of the test compounds in two in vitro modes (isolated guinea pig tracheal chain preparation, isolated guinea pig ileum) supports the promise and accuracy of the prediction. Among them, 4a was the most potent antihistaminic (IC50 value of 30.2 μM; standard, chlorpheniramine maleate showed an IC50 of 14.1 μM).

Evaluation of antitussive and anti-asthmatic activity of Tabernaemontana divaricata(L.) R. Br. Ex Roem. and Schult.

Background:The study was aimed to investigate the antitussive and anti-asthmatic activities of ethanolic extract of Tabernaemontana divaricata (TDEE) leaves by in vivo and in vitro models. Recently, indole alkaloids (monoterpenoid indole alkaloids) have been approved as investigational new drug for clinical trial in respiratory diseases, and T. divaricata has already proven its potential for the presence of indole alkaloids.Materials and Methods:Acute toxicity studies of TDEE were performed in accordance with the Organization for Economic Cooperation and Development guidelines no. 425. The sensitized guinea pigs were screened out and divided into control, standard, and TDEE-treated groups. Anti-asthmatic activity of TDEE was assessed by in vitro guinea pig tracheal chain method and in vivo bronchoprotective test method using aminophylline as a standard drug. Taken codeine as standard, antitussive activity was evaluated by in vivo citric acid-induced tussive response.Results:TDEE was found to be safe up to 2000 mg/kg, body weight. TDEE exhibits maximum bronchi relaxation of 91.66% and 92.83% against acetylcholine and histamine-induced contraction, respectively. TDEE exhibited maximum and significant (P < 0.001) bronchoprotection of 42.28% at the dose level of 200 mg/kg, body weight. TDEE at aerosolic dose of 6% (w/v) exhibited decreased average cough frequency (4.83 ± 0.30) which is quite significant (P < 0.001) and effective as compared to standard drug codeine. Based on the histopathological evidences, TDEE-treated groups showed reduced inflammatory cell infiltration and had restored epithelial damage.Conclusion:The results of the study revealed the potent antitussive and anti-asthmatic activities of T. divaricata, which support its further implication for the treatment of cough-associated complications such as cough variant asthma.

Evaluation of Surinamese Medicinal Plants for their Potential Bronchospasmolytic Effects in Isolated Guinea Pig Tracheal Chains

Evaluation of Surinamese Medicinal Plants for their Potential Bronchospasmolytic Effects in Isolated Guinea Pig Tracheal Chains

Contribution of water and lipid soluble substances in the relaxant effects of Tymus vulgaris extract on guinea pig tracheal smooth muscle in vitro.

To examine the relaxant effects of hydro-ethanolic, macerated aqueous (MA) and lipidfree macerated aqueous (LFMA) extract of Tymus vulgaris on tracheal chains of guinea pigs. The relaxant effects of five cumulative concentrations of each extract (0.4, 0.8, 1.2, 1.6 and 2.0 g/100 mL) were compared with saline as negative control and five cumulative concentrations of theophylline (0.1, 0.2, 0.4, 0.6 and 0.8 mmol/L) on precontracted tracheal smooth muscle of guinea pig with 60 mmol/L KCl (group 1) and 10 µmol/L methacholine (group 2, n=6 for each group). In group 1 all concentrations of theophylline, three higher concentrations of hydro-ethanolic, two concentrations of LFMA and last concentration of MA extracts showed significant relaxant effects compared with that of saline (P<0.05 or P<0.01). Two lower concentrations of LFMA and all concentrations of MA except higher one caused contraction compared with saline (P<0.05 or 0.01). In group 2 experiments, all concentrations of theophylline, hydro-ethanolic, MA and LFMA extracts showed significant relaxant effects compared to that of saline (P<0.05 or P<0.01). In both groups, the relaxant effect of all concentrations of hydro-ethanolic extract were significantly higher than most concentrations of others (P<0.05 or P<0.01). The relaxant effect of different concentrations of three extracts were significantly greater in group 2 compared with group 1 experiments (all P<0.01). There were significantly positive correlations between the relaxant effects and concentrations for theophylline and all extracts in both groups (P<0.05 or P<0.01). Hydro-ethanolic extract has a potent weaker relaxant effect for other extracts from Tymus vulgaris on tracheal chains of guinea pigs.

The preventive effects of natural adjuvants, G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-Γ (th1/th2 balance) in sensitized guinea pigs

OBJECTIVE:The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs.METHODS:The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n = 7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin.RESULTS:The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases).CONCLUSIONS:These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs.

The effect of single dose of thymoquinone, the main constituents of Nigella sativa, in guinea pig model of asthma.

Introduction: In previous studies, the relaxant and antihistaminic effects of thymoquinone, the main constituents of Nigella sativa, have been demonstrated on guinea pig tracheal chains. In the present study, the prophylactic effect of (IP) single dose of thymoquinone on tracheal responsiveness and lung inflammation of guinea pig model of asthma was examined. Methods: Thirty guinea pigs were randomly divided to 3 groups; control (C), sensitized (S) and pretreated group with (TQ); 3 mg/kg, IP (S+TQ). Tracheal responsiveness to methacholine and ovalbumin (OA), total and differential cell count in bronchoalveolar lavage, lung pathological changes and blood Interleukin 4(IL-4) and Interferon gamma (IFNγ) level in three groups were measured. Results: Increased tracheal responsiveness to methacholine and OA, lung lavage fluid white blood cell (WBC) and eosinophil count, IL-4 and IFN-γ levels and pathological changes were seen in sensitized group in comparison to control group (p<0.001 to p<0.05). Decreased tracheal responsiveness to methacholine and OA, pathological changes and bronchoalveolar lavage eosinophil were observed in S+TQ group compared to S group (p<0.001 to p<0.05). However, tracheal responsiveness to methacholine and OA, contractility, bronchoalveolar lavage WBC and eosinophil and most of pathological changes in S+TQ group were significantly higher than those in controls (p<0.01 to p<0.05). Conclusion: These results showed the preventive effect of single dose of thymoquinone on guinea pig model of asthma.

Relaxant effects of asafoetida extract and its constituent umbelliprenin on guinea-pig tracheal smooth muscle.

To investigate the relaxant effects of the asafoetida (Ferula Asafoetida Oleo-Gum-Resin) and its coumarin constituent umbelliprenin on tracheal chains of guinea pigs. The relaxant effects of three cumulative concentrations of the aqueous extract (2, 5 and 10 mg/mL), umbelliprenin (0.04, 0.2 and 0.4 mg/mL), theophylline (0.05, 0.1 and 0.15 mg/mL) and saline were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mmol/L KCl (group 1), and 10 μ mol/L methacholine (group 2). In group 1 all concentrations of theophylline and the highest concentration of the extract showed signififi cant relaxant effects compared with that of saline (P<0.01 for theophylline and P<0.05 for extract). In group 2, relaxant effects of all concentrations of theophylline, extract and two higher concentrations of umbelliprenin differed significantly compared with saline [P<0.01 for all cases except low concentration of umbelliprenin (0.04 mg/mL)]. There were no signififi cant differences between relaxant effects of the extract and theophylline in group 2. The relaxant effect of the extract in group 2 was signififi cantly greater than that of group 1 (P<0.01). The relaxant effect of the extract was significantly more potent than umbelliprenin in all groups (P<0.05 or P<0.01). These results showed a potent relaxant effect for the asafoetida extract on tracheal smooth muscle which is, at least, in part, due to its constituent umbelliprenin. A muscarinic receptor blockade was also suggested for the extract.

Evaluation of anti-allergic and anti-anaphylactic activity of ethanolic extract of Zizyphus jujuba fruits in rodents

The present study reports the anti-allergic activity of ethanolic extract of Zizyphus jujuba Mill., Rhamnaceae, and its possible mode of action. The effect of extract of Z. jujuba at different doses (250, 500 and 1000mg/kg, orally) was simulated on studied animal models of asthma and allergy: a) milk induced eosinophilia and leukocytosis; b) compound 48/80 induced mast cell degranulation; and, c) active and passive cutaneous anaphylaxis. In addition, extract of Z. jujuba's effect on sensitized guinea pig ileum (ex vivo) and tracheal chain preparations (invitro) were investigated. Treatment with extract of Z. jujuba at all doses significantly: prevented the milk-induced eosinophilia and compound 48/80 induced degranulation of mesenteric mast cells; decreased passive cutaneous and active anaphylactic reactions. In addition, extract of Z. jujuba inhibited acetylcholine as well as histamine induced tracheal chain contraction, and also antigen induced contraction of sensitized guinea pig ileum (Shultz- Dale inhibition test). Furthermore, it exhibited also free radicals scavenging activity (in vitro). The observed anti-allergic and anti-anaphylactic activity of extract of Z. jujuba may be largely through the stabilization of mast cells by the membrane presence of phytoconstituents (steroidal saponins and flavonoids).

The effect of carvacrol on serum cytokines and endothelin levels of ovalbumin sensitized Guinea-pigs.

Different pharmacological effects of carvacrol including relaxant effect, its inhibitory effect on muscarinic and histamine (H1) and stimulatory effect on β-adrenoceptors have been demonstrated on guinea pig tracheal chains in previous studies. In the present study, the effect of carvacrol on blood IL-4, IFN- γ and endothelin levels of sensitized guinea pigs is examined. Five groups of guinea pigs sensitized to ovalbumin (OA) were given pure drinking water (group S), drinking water containing three concentrations of carvacrol (40, 80 and 160 µg/ml)) and dexamethasone. The blood IL-4, IFN- γ and endothelin levels of sensitized and control guinea pigs were evaluated (n=6, for all groups). Blood IL-4 and IFN-γ levels (P<0.001 for both cases) as well as endothelin (P<0.01) were increased but IFN-γ/IL-4 ratio decreased (P<0.05) in sensitized animals compared to controls. The treatment of S animals by dexamethasone (P<0.01) and two higher concentrations of carvacrol (P<0.001 for both cases) significantly decreased IL-4 level. The treatment of S animals with dexamethasone did not changed IFN-γ levels but treatment with high concentration of carvacrol significantly increased its level (P<0.001). In addition, IFN-γ/IL-4 ratio was significantly increased in S groups, who were treated with dexamethasone (P<0.05) and two higher concentrations of carvacrol (P<0.001 for both cases). Treatment of S animals by dexamethasone (P<0.01) and all concentrations of carvacrol also significantly decreased endothelin level (P<0.01 to P<0.001). The results show that carvacrol causes the reduction of IL-4 and endothelin, but it increases IFN-γ and IFN-γ/IL-4 ratio in the blood of sensitized guinea pigs. The results also suggest more specific effect of carvacrol compared to dexamethasone due to the absence of the effect of later on IFN-γ.