Histamine Aerosol Research Articles

Anti-asthmatic activity of Saudi herbal composites from plants Bacopa monnieri and Euphorbia hirta on Guinea pigs

Abstract Asthma, the respiratory disorder associated with bronchial hyper-responsiveness, affected 300 million people across the globe, with a prevalence of 4.05% in Saudi Arabia and causing 61.6% of hospital emergency room annual visits. Increased side effects of conventional drugs demand the necessity for the development of natural drugs. In this study, an herbal composite from Bacopa monnieri and Euphorbia hirta was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC-MS) analysis. In vitro bacterial inhibition and anti-asthmatic activity were evaluated using animal models. Ethanolic herbal composite (EHC) showed significant anti-pathogenic activities. GC-MS analysis identified potential bioactive compounds and FT-IR analysis revealed functional groups corresponding to plant composites. The EHC increased the preconvulsive time against 1% histamine aerosol compared to control animals. In sensitized + EHC-treated animals, total leukocyte, eosinophil, lymphocyte, neutrophil, and monocyte counts were found to be reduced as compared to sensitized and control groups. EHC decreased malondialdehyde and bicarbonate levels denoting the reduced oxidative burden and increased the antioxidant activity by increased intracellular glutathione (GSH) level. The EHC-treated group showed decreased inflammatory cell infiltration compared to the sensitized. A significant anti-asthmatic effect was observed in the EHC-treated group (P < 0.05). Thus, herbal composites are used in the treatment of asthma and can be used as an alternative to commercially available pharmaceutical drugs.

Evaluation of Antiasthmatic Activity of Eraippu Noi Chooranam (ENC)

Background: Every human race has its own traditional system of medicines. Siddha system of medicine is unique and ancient of its kind originating from Tamil Nadu in India. Siddha system could be considered as the crown of all the traditional arts of the ancient Tamil. Eraippu Noi Chooranam is a modified Siddha Poly Herbal formulation indicated for respiratory diseases in the text Siddha research pharmacopoeia. The indicated traditional claim enforced to evaluate its efficacy in the management of Bronchial asthma.
 Aim and Objective: The aim of study is to evaluate the anti asthmatic activity of ENC in Bronchial asthma.
 Materials and Methods: In the present study, aqueous extract of ENC was evaluated for its anti asthmatic activity using histamine induced bronchospasm, in guinea pig at different dose levels.
 Results: The test drug ENC at all the three doses of 100,200,300 mg/kg p.o significantly (p<0.01) increased the latent period of convulsions following exposure to histamine aerosol when compared to control. The percentage of protection by the standard drug was 82.8 % whereas the protection offered by ENC at 100,200 and 300 mg/kg was found to be 61.5%, 71.1% and 80% respectively. High dose of ENC offered highest protection which was comparable to standard.
 Conclusion: It can be concluded that aqueous extract of ENC may be used in the management of asthma.

In-vitro and in-vivo Evaluation of Anti-asthmatic Activity of Eugenia jambolana bark

Objectives: The present study designed to evaluate the Antiasthmatic activity of aqueous extract of bark of Eugenia Jambolana (AEEJ) on in vitro and in vivo animal models. Materials and methods: Different in vitro and in vivo animal models was used to study the anti asthmatic activity as isolated goat tracheal chain preparation, Acetylcholine and Histamine induced bronconstriction in guinea pigs, effect of drug extract on histamine release from mast cell was checked by clonidine-induced mast cell degranulation, and milk-induced eosinophilia and leukocytosis. Results: In-vitro study on goat tracheal chain preparation revealed that aqueous extract of Eugenia jambolana (AEEJ)bark exerted antagonistic effect on the histamine induced contraction. (P<0.05) The guinea pigs when exposed to 0.2% histamine aerosol showed signs of progressive dyspnoea leading to convulsions. AEEJ significantly prolonged the latent period of convulsions (PCT) as compared to control following the exposure of histamine (0.2%) aerosol (P<0.01). The observation of present study indicates aqueous extract of Eugenia jambolana shows significant inhibition of milk induced eosinophilia and leukocytosis. Group of animals pretreated with aqueous Eugenia jambolana bark extract showed significant reduction in degranulation of mast cells when challenged with clonidine. The prevention of degranulation process by the aqueous Eugenia jambolana bark extract (P<0.01) indicates a possible stabilizing effect on the mast cells, indicating mast cell stabilizing activity. Conclusions: Thus, AEEJ showed antihistaminic, mast cell stabilizing and protective in guinea pigs against histamine induced PCD, reduced eosinophilia and leukocytosis and hence possesses potential role in the treatment of asthma.

Review on Medicinal benefits of London Rocket or SisymbriumIrio in different contextual aspects

Several studies done throughout the world on ‘SisymbriumIrio L’, also known as ‘London Rocket’ or ‘Khakshi’ have established that this annual herb is of tremendous medicinal benefits. This review paper will focus on researches done using samples collected at widespread geographical range such as Jordan, Saudi Arabia, Kashmir, Rawalpindi, Lahore, Rajasthan, UK, Europe, Mediterranean Islands, North America, and Caucasia among others. Further, we will study various phytochemicals produced by aerial parts, seeds, and other partsofSisymbriumIrio L and their clinical uses which were discovered experimentally. Such as alkaloids of aerial parts for ‘Liver Disease’; flavonoids, steroids, and alkaloids in seeds as expectorant and stimulant for ‘Clinical Asthma’; histamine aerosol for protection against ‘Bronchospasm’; ethyl acetate, aqueous extracts, and butanol from other parts as potential ‘Nutraceutical Antioxidant’. Apart from these, there is the presence of various secondary metabolites such as flavonoids, triterpenoids or steroids, saponins, alkaloids, carbohydrates, and tannins, and the absence of Anthraquinones and cardiac glycosides which were found to be of ‘Chemotherapeutic Interest’. Hence we will analyze the overall effects of various phytochemicals produced from different parts of Sisymbriumirio L and further study the possibility to use this plant as a potential replacement for various commercially used Antibiotics.

Examination of Bronchial Reactivity in Workers Exposed to Microparticles PM2.5 and PM10 during Coal Surface Mining in the Bellaqevc Power Plants of Kosovo

The impact of air pollution with microparticles (PM2.5 and PM10) on the respiratory systems of workers engaged in thesurface mining of coal at the Bellaqevc power plants of Kosovo is studied in this paper. The parameters of lung functionare defined via body plethysmography. The resistance of the airways (Raw) was recorded, intrathoracic gas volume (ITGV) was measured, and the specific resistanceof the airways (SRaw) and specific conductance (SGaw) were calculated. The research was performed withintwo groups: a control group and experimental group. The control group consisted of 28 healthy people, whereas the experimental group consisted of 50 workers engaged in the surface mining of coal at the Bellaqevc power plants of Kosovo.
 The results obtained from this research indicated that the mean specific resistance (SRaw) was ​​significantly increased in the experimental group (p<0.01) compared to the control group (p>0.1). The study also found that smoking favors the adverse effects of air pollution caused by coalsurface mining at the Bellaqevc power plants (p<0.01).
 Measurements of the respiratory systems were made prior to and following provocation with histamine–aerosol (1 mg/ml) in the control and experimental groups. Changes between these two groups following this provocation with histamine–aerosol were found to be statistically significant (p<0.01).
 In order to cause a respiratory pathology from air pollution, it is required a lot of time, such pollution can permanently cause respiratory system disorders. These scientific findings suggest that the long-term exposure of workers to microparticles PM2.5 and PM10 during the processof surface mining coal at the Bellaqevc power plants of Kosovo poses a risk to their health by causing increased bronchial reactivity, bronchial asthma, orchronic obstructive pulmonary disease (COPD).

Bronchospasmolytic and Adenosine Binding Activity of 8- (Proline / Pyrazole)- Substituted Xanthine Derivatives.

8-Phenyltheophylline derivatives exhibit prophylactic effects at a specific dose but do not produce the cardiovascular or emetic side effects associated with xanthines, thereby exhibiting unique characteristics of potential therapeutic importance. Novel series of 8-(proline/pyrazole)-substituted xanthine analogs have been synthesized. The affinity and selectivity of compounds to adenosine receptors have been assessed by radioligand binding studies. The synthesized compounds also showed good bronchospasmolytic properties (increased onset of bronchospasm; decreased duration of jerks) with 100% survival of animals in comparison to the standard drug. Besides, compound 8f & 9f showed good binding affinity in comparison to other synthesized compounds in the micromolar range. The maximum binding affinity of these compounds was observed for A2B receptors, which was ~ 7 or 10 times higher as compared to A1, A2A and A3 receptors. The newly synthesized derivatives 8f, 9a-f, 17g-m, and 18g-m displayed significant protection against histamine aerosol induced bronchospasm in guinea pigs. Newly synthesized proline/pyrazole based xanthines compounds showed a satisfactory binding affinity for adenosine receptor subtypes. Replacement or variation of substituted proline ring with substituted pyrazole scaffold at the 8th-position of xanthine moiety resulted in the reduction of adenosine binding affinity and bronchospasmolytic effects.

MANIFESTATION OF BRONCHIAL REACTIVITY IN THE WORKERS EXPOSED TO VARIOUS GASES AT THE GASIFICATION DEPARTMENT OF THE POWER PLANTS OF KOSOVO

Objective: This study aimed to determine the effects of indoor air pollution on workers and the effects of discharged gases, such as CO, CO2, NO2, O3, SO2, NH3, and PM, on the manifestation of bronchial reactivity during the process of gasification at the power plants in Kastriot, Kosovo.
 Methods: Parameters of lung function were determined using body plethysmography. Airway resistance (Raw) and intrathoracic gas volume (ITGV) were measured; based on these values, specific airway resistance (SRaw) and specific airway conductance were calculated.
 Results: The study was performed in two groups: the control group and the experimental group. The control group consisted of 32 healthy people, whereas the experimental group consisted of 55 workers of the gasification department of the power plants in Kastriot, Kosovo. The results of this study indicated that the mean value of SRaw significantly increased in the experimental group (p<0.05) compared to the control group (p>0.1). This study also showed that smoking is in favor of the negative effects of air pollution at the premises of the gasification department (p<0.01). Measurements of the respiratory systems were made before and following provocation with histamine–aerosol (1 mg/ml) in the control and experimental groups. Changes between these two groups following this provocation with histamine–aerosol were found to be statistically significant (p<0.01).
 Conclusion: Although air pollution requires time to cause a respiratory pathology, it permanently affects the manifestation of bronchial reactivity. This finding suggests that the real situation of these workers exposed to air pollution during the process of gasification poses a serious risk to their health and particularly to normal respiratory function.

PHYTOASSEMBLY AND PHARMACOLOGICAL ACTIVITY ON MORINGA OLEIFERA: A REVIEW

Moringa oleifera is a plant that has copious medicative properties and widely known as “drumstick plant” or “horseradish plant” and most widely vascular plant in India. This is a nutritional plant (herb) that consists of many pharmacological and biological exertion such as antiasthmatic, diuretic, antiepileptic, cardiovascular as well as antioxidants and also beneficial in wound healing enterprise. The anti-asthmatic action of M. oleifera seeds kernel ethanolic extract evoked by histamine and acetylcholine aerosol. Pre-treatment by ethanol gives the extract of M. oleifera also diminished carrageenan convinced rat paw edema that was comparable to standard diclofenac sodium. This review summarizes the biological exertion such as a cardiovascular, diuretic, and biological activities such as antimicrobial, antiepileptic, and anti-allergic activities and also provides pharmacological activities in essence anti-cancer, anti-diabetic, and anti-asthmatic activities.

Evaluation of antihistaminic activity of quercetin by using histamine induced bronchospasm and clonidine induced catalepsy models

Background: Histamine is an important mediator of allergic reactions. Even though presently available antihistaminics are effective in treatment of allergic reactions, still there is scope for better new drugs. Quercetin has been used as a nutritional supplement and may be beneficial against a variety of diseases. Some of the beneficial effects include anticancer, antitumor, anti-ulcer, anti-allergy and anti-inflammatory effects. As quercetin is used in traditional system of medicine for treatment of allergies, this study was undertaken to evaluate antihistaminic activity of quercetin.Methods: In histamine induced bronchospasm model, 18 guinea pigs were divided into 3 groups. Control group received normal saline, standard control group received Chlorpheniramine and test group received Quercetin. All drugs were given once daily for 5 days. Preconvulsive dyspnoea was calculated on day 0 and day 5 for all guinea pigs after administration of Histamine aerosol. In clonidine induced catalepsy model, 18 albino mice were divided into 3 groups. Control group, standard control group and test group received normal saline, Chlorpheniramine and Quercetin respectively. One hour after administration of drugs the mice were given clonidine and catalepsy was measured at 30, 60, 90, 120 and 150 min.Results: In histamine induced bronchospasm model, both chlorpheniramine and quercetin produced significant protection as compared to control group. In clonidine induced catalepsy model the effect of quercetin was comparable to chlorpheniramine.Conclusions: Quercetin has significant antihistaminic activity. It appears to be due to H1 receptor blockade, contrary to the belief that it inhibits release of histamine from mast cells.

Evaluation of the anti-asthmatic and antitussive potentials of methanol leaf extract of Napoleona vogelii in rodents

Napoleona vogelii is used in ethnomedicine for the treatment of asthma and cough. This study evaluated antiasthmatic and antitussive properties of its methanol leaf extract (NVE) in rodents. Phytochemical screening was conducted using established methods. Acute oral toxicity test was done in mice and guinea pigs. Ovalbumin (OA)-sensitized guinea pigs were orally pretreated with 100, 200 or 400 mg/kg/day of NVE or 0.5 mg/kg/day of salbutamol for 14 days before exposure to 0.2% histamine aerosol. Latency to preconvulsive dyspnea (PCD), tracheal fluid volume (TFV), flow rate (FR), and tracheal morphometry (TM) were evaluated. Tracheal rings from sensitized guinea pigs were tested in organ baths for antispasmodic and spasmolytic effects. Citric acid and ammonium hydroxide cough models were used to evaluate antitussive effects in guinea pigs and mice respectively. Tannins, alkaloids, flavonoids, and phenolic substances were found in NVE. LD50 values in mice and guinea pigs were greater than 5000 mg/kg. NVE caused a significant (P < 0.05) increase in the latency to PCD and a decrease in TFV in the group treated with 200 mg/kg. TM indicated a reduction in airway narrowing in NVE-treated groups. The presence of NVE significantly attenuated responses of tracheal rings to carbachol. Its addition to carbachol precontracted rings resulted in significant relaxation. Emax for calcium concentration-response was significantly (P < 0.01) decreased in the presence of NVE. Cough bouts dose-dependently decreased significantly (P < 0.05) in guinea pigs and mice. We conclude that NVE seems safe and possesses anti-asthmatic effect that involves inhibition of calcium influx. It also has antitussive properties that may be peripherally mediated.

Evaluation of the anti-asthmatic and antitussive effects of concurrently administered extracts of &lt;i&gt;Bryophyllum pinnatum&lt;/i&gt; and &lt;i&gt;Andrographis paniculata&lt;/i&gt; in rodents

We evaluated the anti-asthmatic and antitussive effects of concurrently administered doses of aqueous Bryophyllum pinnatum (BP) and methanol Andrographis paniculata (AP) extracts in rodents. Doses of 200 and 400 mg/kg of BP were variously administered concurrently with 4 or 8 mg/kg of AP. In the anti-asthmatic evaluation, ovalbuminsensitized guinea pigs were given oral doses of both extracts for seven days and then exposed to 0.2% histamine aerosol in a glass chamber. Latency to preconvulsive dyspnea (PCD), tracheal fluid volume and viscosity were measured. In guinea pigs given acute doses of the extract, bouts of cough were counted after exposure to 7.5% citric acid aerosol. Phenol red expectoration was estimated in mice after 7 days of treatment with the extracts. Doses of BP administered alone significant increased latency to PCD (P < 0.05); and reduced the number of cough bouts (P < 0.0001). The concurrent administration of 400 mg/kg BP with the doses of AP significantly increased latency to PCD compared to 400 mg/kg BP alone. Doses of AP significantly altered the antitussive effect of BP but significantly reversed the reduction of phenol red release by 400 mg/kg BP. We conclude that while concurrent administration of 400 mg/kg BP with doses of AP may be beneficial in asthma, this is not the case in cough. This has implication on the label indications following possible co formulation of the extracts. Keywords: Concurrent extract administration, Asthma, cough, expectoration

Evaluation of Bronchodilator Activity of Siddha Herbo Mineral Drug “Vasanthakusumakara Mathirai” by Exposing Guinea Pig in Histamine Aerosol

Evaluation of Bronchodilator Activity of Siddha Herbo Mineral Drug “Vasanthakusumakara Mathirai” by Exposing Guinea Pig in Histamine Aerosol

Anti-allergy and anti-tussive activity of Clitoria ternatea L. in experimental animals

Ethnopharmacological relevanceClitoria ternatea flower is traditionally used in the treatment of respiratory disorders including bronchitis and is one of the ingredients in different Ayurvedic preparations that are used in respiratory disorders. However, till date there is no scientific report on the anti-asthmatic activity of this flower. Aim of the studyEthanolic extract of Clitoria ternatea flowers (ECT) was evaluated for its anti-allergy and anti-tussive potential in experimental animals. Additionally, the anti-inflammatory potential of ECT was carried out to draw a plausible mechanism of action of the drug. Materials and MethodsIn-vitro anti-asthmatic activity of ECT was evaluated in goat tracheal chain and isolated guinea pig ileum preparations. Acute and chronic anti-asthmatic activity of ECT (100, 200 and 400 mg/kg; p.o.) was estimated in histamine aerosol exposed guinea pigs and in OVA sensitized and challenged mice respectively. Anti-tussive activity of ECT (100, 200 and 400 mg/kg; p.o.) was evaluated against sulfur dioxide- and citric acid-induced cough in experimental animals. Moreover, the anti-inflammatory activity of ECT (100, 200 and 400 mg/kg; p.o.) was evaluated against carrageenan- and acetic acid-induced inflammation in rats. ResultsECT attenuated histamine-induced contraction in both goat tracheal chain and isolated guinea pig ileum preparations. ECT (400 mg/kg) attenuated histamine-induced dyspnoea and OVA-induced changes in differential cell count in broncheoalveolar fluid, levels of interleukins (IL-1beta and IL-6) and immunoglobulin (OVA-sensitive IgG1) in animals. ECT (400 mg/kg) further ameliorated sulfur dioxide- and citric acid-induced cough in experimental animals. Additionally, ECT (400 mg/kg) attenuated inflammation in carrageenan and acetic acid challenged rodents. ConclusionsStandardized ECT could be considered as a potential therapeutic alternative in the management of allergy-induced asthma.

Anti asthmatic effect of Momordica Charantia and its comparison with montelukast an in vitro and in vivo model

Background: Momordica charantia (MC) (bitter gourd) have shown the inhibition of NF-κβ and Leukotrienes expression in many inflammatory pathological conditions. Based on ist anti-inflammatory action this study aimed to Identify MC fruit dry powder (MCp) and MC fresh juice (MCj) action on airway inflammation in Guinea Pig model and also to find out the presence of alkaloids and flavonoides.Methods: 18 adult Guinea pigs of both sexes (excluding mating animals) were randomly divided into three groups with six animals in each namely Montelukast, MCj and MCp groups respectively. They were given with OD oral administration of concerned drugs for 1 -7 days. 6 control animals were exposed to 2% histamine aerosol for 120 seconds using histamine chamber prior to treatment with Montelukast, MCj and MCp to observe the normal Pre-Convulsive Dyspnea (PCD) in seconds. After six hours of daily OD oral dose of test drugs administration, all the groups’ were exposed to 2% Histamine aerosol one by one for 120 sec on day1 &amp; 7 to observe PCD. The MCj and MCp were also tested with chemical assay, TLC to confirm the presence of alkaloids, flavonoides.Results: ON DAY 1 and 7: MCj and MCp showed significant decrease in PCD occurrence and it is statistically significant compared to the control. PCD blocking action of MCj group was effective in DAY 1. TLC and Chemical Assay were not supportive for bronchodilator action.Conclusions: MCj and MCp have promising preventive role in asthma. This study had expressed the positive protective role of Momordica charantia in asthmatic condition based on its known anti-inflammatory action.

Effect of Angelica glauca essential oil on allergic airway changes induced by histamine and ovalbumin in experimental animals

Objective:Angelica glauca Edgew (Apiaceae) is used in traditional medicine for treatment of several diseases including bronchial asthma. The present investigation was aimed to evaluate broncho-relaxant activity of A. glauca essential oil in histamine and ovalbumin (OVA)-induced broncho constriction in experimental animals.Materials and Methods:Airway was induced using histamine aerosol in guinea pigs (n = 24) and OVA aerosol in albino mice (n = 24). The number of inflammatory cells, namely, absolute eosinophils count in blood, total immunoglobulin E (IgE) in serum, eosinophils, and neutrophils in bronchoalveolar lavage fluid (BALF) and histopathological examination of lung tissues were investigated in A. glauca oil and dexamethasone-treated groups. A. glauca oil 200 μL/kg was given orally, and dexamethasone 2 mg/kg was given intraperitoneal. Both the treatments were repeated daily for 7 days. Results were analyzed by one-way ANOVA, and P ≤ 0.05 was considered statistically significant.Results:Treatment with A. glauca essential oil significantly (P < 0.001) increased the time of preconvulsive dyspnea in histamine-induced guinea pigs. Oral treatment of A. glauca oil significantly (P < 0.001) decreased absolute blood eosinophil count (from 325 ± 3.69 to 200 ± 3.05 cells/mm3), serum level of IgE (from 6.10 ± 0.05 to 0.70 ± 0.08 IU/L), and the number of eosinophils (from 11.0% ±1.41% to 3.0% ±0.51%), neutrophils (from 13.0% ±1.12% to 5.0% ±1.39%) in BALF. Histopathological changes observed in lungs of untreated group were marked suppressed by treatment with A. glauca oil.Conclusion:The essential oil of A. glauca has bronchorelaxation in both histamine and OVA-induced bronchoconstriction in animals. The traditional use of A. glauca against asthma could be attributed to its bronchodilator property as observed in the present study.

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.

Evaluation of the Anti-asthmatic and Antitussive Effects of Aqueous Leaf Extract of Ocimum gratissimum in Rodents

Background: Ocimum gratissimum Linn (Lamiaceae) is an aromatic plant popular for it culinary uses. The aqueous leaf extract is used in ethnomedicine for the treatment of various diseases including asthma and cough. The purpose of this study was to evaluate the anti-asthmatic, antitussive and muco-suppressant effects of the aqueous leaf extract (OGE) in rodent species. Methods: Ovalbumin-sensitized guinea pigs were exposed to 0.2% histamine aerosol in a glass chamber. Latency to preconvulsive dyspnea (PCD), tracheal fluid volume and viscosity were measured. For the antitussive screening, guinea pigs were exposed to 7.5% citric acid aerosol in a glass chamber and the bouts of cough pre and post-acute exposure were recorded. Mucus expectoration was estimated in mice after seven-day treatment with OGE. Results: Latency to preconvulsive dyspnea was not significantly increased by doses of 100, 200 and 400 mg/ kg of OGE when compared with distilled water-treated sensitized guinea pigs. Tracheal fluid volume but not viscosity was significantly (p<0.0001) reduced by all the doses of OGE when compared with distilled water-treated sensitized guinea pigs. Also, the doses of OGE significantly reduced (p<0.0001) the number of cough bouts when compared with distilled water control. All the doses of extract significantly (p<0.003) reduced phenol red dye expectoration from mice tracheae. Conclusion: The aqueous leaf extract of O. gratissimum does not protect against acute bronchospasms but possesses antitussive and muco-suppressant effects that may be helpful in asthmatics. Central mechanism may be contributory to the antitussive effect. These results lend credence to its ethnomedicinal use in the treatment of these diseases.

Effects of lung inflation on airway heterogeneity during histaminergic bronchoconstriction

Lung inflation has been shown to dilate airways by altering the mechanical equilibrium between opposing airway and parenchymal forces. However, it is not known how heterogeneously such dilation occurs throughout the airway tree. In six anesthetized dogs, we measured the diameters of five to six central airway segments using high-resolution computed tomography, along with respiratory input impedance (Zrs) during generalized aerosol histamine challenge, and local histamine challenge in which the agonist was instilled directly onto the epithelia of the imaged central airways. Airway diameters and Zrs were measured at 12 and 25 cmH2O. The Zrs spectra were fitted with a model that incorporated continuous distributions of airway resistances. Airway heterogeneity was quantified using the coefficient of variation for predefined airway distribution functions. Significant reductions in average central airway diameter were observed at 12 cmH2O for both aerosolized and local challenges, along with significant increases upon inflation to 25 cmH2O. No significant differences were observed for the coefficient of variation of airway diameters under any condition. Significant increases in effective airway resistance as measured by Zrs were observed only for the aerosolized challenge at 12 cmH2O, which was completely reversed upon inflation. We conclude that the lung periphery may be the most dominant contributor to increases in airway resistance and tissue elastance during bronchoconstriction induced by aerosolized histamine. However, isolated constriction of only a few central airway segments may also affect tissue stiffness via interdependence with their surrounding parenchyma.

Studies on the anti-asthmatic and antitussive properties of aqueous leaf extract of Bryophyllum pinnatum in rodent species

ObjectiveTo evaluate the antiasthmatic and antitussive properties of the aqueous leaf extract of Bryophyllum pinnatum (B. pinnatum) (BP) Lam. MethodsOvalbumin-sensitized guinea pigs which were treated with BP for 21 consecutive days were exposed to 0.2% histamine aerosol in a glass chamber. Mucus viscosity, white blood cell and lymphocyte counts and tracheal wall morphometry were measured. Bouts of cough were counted pre and post acute exposure of extract-treated (× 7 d) guinea pigs to 7.5% citric acid aerosol in a chamber. Phenol red expectoration was estimated in mice after 7 d of daily administration of BP. ResultsDoses of 200 and 400 mg/kg/day (×21 d) BP significantly increased the time for guinea pigs to experience preconvulsive dyspnoea. BP and salbutamol (0.5 mg/kg/day ×21 d) reduced mucus viscosity in the sensitized group to values comparable with controls. White blood cell, lymphocyte counts and tracheal morphometry were not significantly altered. Both doses of BP also significantly reduced the bouts of cough but only 400 mg/kg/day significantly inhibited the amount of phenol red secreted. ConclusionsBP has demonstrated antiasthmatic and antitussive properties in these rodent models. These properties may underscore its use in Nigerian ethnomedicine.

Evaluation of the protective and ameliorative properties of Garcinia kola on histamine-induced bronchoconstriction in guinea pigs

Background:Garcinia kola is popularly used in African traditional medicine for the relief of acute bronchoconstrictive episodes.Objective:In this study, we examined the anti-asthmatic and morphological effects of the ethanol extract of G. kola in animal model.Materials and Methods:Guinea pigs were sensitized with ovalbumin and then given doses of 200 or 400 mg/kg/day for 21 consecutive days. Theophylline (10 mg/kg/day) was used as a standard. At the end of the exposure, the animals were exposed to 0.2% histamine aerosol in a chamber. Lymphocyte count, bronchial histology and morphometry were done.Results:Compared with non-sensitized controls, 200 mg/kg/day dose of the extract significantly (P < 0.05) increased the time taken for onset of preconvulsive dyspnea while the dose of 400 mg/kg/day significantly (P < 0.01) reduced bronchial wall thickness. Lymphocytes counts were not significantly affected but the bronchi of extract-treated animals were histologically clearer of lesions visible in the sensitized.Conclusion:These protective and ameliorative properties lend credence to the use of G. kola in ethnomedicine.