Screening models for anti-asthmatic drugs MCQs With Answer

Introduction: Screening models for anti-asthmatic drugs are essential tools for B. Pharm students to understand how candidate compounds affect bronchoconstriction, airway inflammation, and remodeling. These models include in vivo animal models (ovalbumin‑sensitized mice, guinea pig tracheal chain, methacholine or histamine challenge), ex vivo preparations (isolated trachea, lung slices), and in vitro assays (mast cell degranulation, bronchial epithelial cells, RBL‑2H3). Key endpoints include airway hyperresponsiveness, eosinophilia, cytokine profiles (IL‑4, IL‑5, IL‑13), BALF analysis, and lung histopathology. Knowledge of pharmacology, protocol design, controls, and limitations ensures reliable screening of bronchodilators, anti‑inflammatories, and mast cell stabilizers. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which in vivo model is commonly used to study IgE‑mediated allergic airway inflammation and eosinophilia?

• Ketamine/xylazine acute bronchospasm model
• Ovalbumin‑sensitized mouse model
• Histamine nebulization in isolated trachea
• In vitro bronchial epithelial scratch assay

Correct Answer: Ovalbumin‑sensitized mouse model

Q2. The guinea pig tracheal chain preparation is primarily used to evaluate which pharmacological effect?

• Anti‑fibrotic activity
• Mucus production inhibition
• Bronchorelaxant/bronchoconstrictor responses
• Antigen presentation by dendritic cells

Correct Answer: Bronchorelaxant/bronchoconstrictor responses

Q3. Which in vitro cell line is frequently used for mast cell degranulation and IgE‑dependent assays?

• RAW 264.7 macrophages
• RBL‑2H3 cells
• A549 alveolar epithelial cells
• HEK293 kidney cells

Correct Answer: RBL‑2H3 cells

Q4. In methacholine challenge tests, the primary endpoint used to quantify airway hyperresponsiveness in animals is:

• Bronchoalveolar lavage fluid (BALF) protein concentration
• Degranulation index of mast cells
• Airway resistance or Penh/PC20 values
• Serum IgG levels

Correct Answer: Airway resistance or Penh/PC20 values

Q5. Which biomarker in BALF indicates eosinophilic inflammation in asthma models?

• Neutrophil elastase
• Eosinophil count
• ALT enzyme activity
• CD8+ T‑cell percentage

Correct Answer: Eosinophil count

Q6. Passive cutaneous anaphylaxis (PCA) is used to assess which property of a compound?

• Bronchial smooth muscle contractility
• Ability to block IgE‑mediated immediate hypersensitivity
• Chronic airway remodeling effects
• Inhibition of T‑cell proliferation

Correct Answer: Ability to block IgE‑mediated immediate hypersensitivity

Q7. A common adjuvant used in animal sensitization protocols for allergic asthma models is:

• Aluminum hydroxide (alum)
• Lipopolysaccharide (LPS) alone
• Sodium chloride
• Polyethylene glycol (PEG)

Correct Answer: Aluminum hydroxide (alum)

Q8. Ex vivo precision‑cut lung slices (PCLS) are advantageous because they allow assessment of:

• Whole‑animal behavioral responses
• Isolated airway responses within native lung architecture
• Systemic pharmacokinetics
• Serum antibody titers

Correct Answer: Isolated airway responses within native lung architecture

Q9. Which cytokine is most directly associated with Th2‑type responses in allergic asthma?

• IFN‑gamma
• IL‑12
• IL‑4
• TNF‑alpha

Correct Answer: IL‑4

Q10. In organ bath studies of isolated trachea, the potency of a bronchodilator is commonly expressed as:

• Area under the curve (AUC) only
• EC50 value
• mg/kg oral dose
• Tissue wet weight

Correct Answer: EC50 value

Q11. Which readout best indicates mast cell stabilization in an in vitro assay?

• Increased histamine release
• Decreased histamine or β‑hexosaminidase release
• Elevated IL‑17 secretion
• Enhanced IgA production

Correct Answer: Decreased histamine or β‑hexosaminidase release

Q12. Leukotriene receptor antagonists are primarily screened using models that measure:

• Neutrophil chemotaxis
• Bronchoconstriction and leukotriene levels
• Fibroblast proliferation only
• Platelet aggregation

Correct Answer: Bronchoconstriction and leukotriene levels

Q13. Forced oscillation technique (FOT) in small animals measures:

• Serum cytokine concentrations
• Airway mechanics including resistance and compliance
• Bronchial epithelial cell proliferation
• Histological goblet cell counts

Correct Answer: Airway mechanics including resistance and compliance

Q14. Which component of BALF is commonly quantified to evaluate airway inflammation severity?

• Epithelial cell DNA methylation
• Total and differential cell counts
• Hemoglobin concentration
• Cerebrospinal fluid contamination

Correct Answer: Total and differential cell counts

Q15. For preclinical screening, what is a major limitation of the ovalbumin mouse model?

• It perfectly replicates human asthma immunopathology
• It ignores airway inflammation entirely
• It is an acute Th2‑biased model that may not reflect chronic human disease
• It lacks any measurable cytokine changes

Correct Answer: It is an acute Th2‑biased model that may not reflect chronic human disease

Q16. Which measurement indicates airway remodeling in chronic asthma models?

• Short‑term bronchospasm only
• Increased subepithelial collagen deposition and smooth muscle mass
• Reduced serum albumin
• Decreased liver enzymes

Correct Answer: Increased subepithelial collagen deposition and smooth muscle mass

Q17. A positive control when testing a novel β2‑agonist in animal bronchoconstriction assays would be:

• Saline nebulization
• Sodium cromoglycate
• Salbutamol (albuterol)
• DMSO vehicle

Correct Answer: Salbutamol (albuterol)

Q18. Which assay is suitable for measuring leukotriene production from stimulated airway cells?

• ELISA for LTC4/D4/E4
• qPCR for housekeeping genes
• Flow cytometry for CD3
• Western blot for actin

Correct Answer: ELISA for LTC4/D4/E4

Q19. In studies of inhaled drugs, which administration route best mimics clinical delivery for bronchodilators?

• Intraperitoneal injection
• Oral gavage
• Intravenous bolus
• Aerosol/nebulized inhalation

Correct Answer: Aerosol/nebulized inhalation

Q20. Reduction in airway hyperresponsiveness after treatment is best demonstrated by which observation?

• Higher airway resistance in response to methacholine
• No change in BALF cellularity
• Shift to the right in the dose‑response curve (increased PC20/EC50)
• Increased IgE titers

Correct Answer: Shift to the right in the dose‑response curve (increased PC20/EC50)

Q21. Which histological stain is commonly used to visualize mucus‑producing goblet cells in airway tissue?

• Hematoxylin and eosin (H&E) only
• Periodic acid–Schiff (PAS) stain
• Gram stain
• Oil Red O

Correct Answer: Periodic acid–Schiff (PAS) stain

Q22. During protocol design, why is selection of an appropriate vehicle control important?

• Vehicles never influence airway responses
• To ensure observed effects are due to test compound and not solvent effects
• Vehicle controls replace positive controls
• They increase variability intentionally

Correct Answer: To ensure observed effects are due to test compound and not solvent effects

Q23. Measurement of serum total and antigen‑specific IgE in allergic models helps to:

• Assess neutrophil recruitment only
• Quantify humoral sensitization and allergic status
• Evaluate drug metabolism
• Determine liver toxicity

Correct Answer: Quantify humoral sensitization and allergic status

Q24. An advantage of using human primary bronchial epithelial cells in vitro is:

• They require no ethical considerations
• They fully replicate in vivo airway complexity
• They allow human‑relevant assessment of cytokine and barrier responses
• They are immortal and unlimited

Correct Answer: They allow human‑relevant assessment of cytokine and barrier responses

Q25. Which endpoint would most directly indicate reduced airway inflammation after drug treatment?

• Increased Penh value
• Decreased eosinophil percentage in BALF
• Elevated serum ALT
• Higher mucous metaplasia score

Correct Answer: Decreased eosinophil percentage in BALF

Q26. What is a critical ethical consideration when using animal models for anti‑asthmatic drug screening?

• Maximizing animal numbers irrespective of study design
• Applying the 3Rs: Replacement, Reduction, and Refinement
• Avoiding approval from institutional committees
• Using lethal endpoints without justification

Correct Answer: Applying the 3Rs: Replacement, Reduction, and Refinement

Q27. Which technique can quantify airway smooth muscle contraction in isolated tracheal rings?

• Organ bath tension recording
• ELISA for IgE
• High‑performance liquid chromatography (HPLC)
• Confocal microscopy for mitochondria only

Correct Answer: Organ bath tension recording

Q28. A decrease in airway neutrophils but persistent eosinophilia after treatment suggests the drug primarily targets:

• Th2 eosinophilic pathways
• Neutrophilic inflammation selectively
• Non‑inflammatory mechanisms only
• Broad immunosuppression

Correct Answer: Neutrophilic inflammation selectively

Q29. In screening anti‑asthmatic compounds, why include both acute bronchoconstriction and chronic inflammation models?

• They are redundant and unnecessary
• To evaluate both immediate bronchodilator action and long‑term anti‑inflammatory/remodeling effects
• To focus only on pharmacokinetics
• Because chronic models are cheaper always

Correct Answer: To evaluate both immediate bronchodilator action and long‑term anti‑inflammatory/remodeling effects

Q30. Which statistical practice is essential for reliable interpretation of screening model results?

• Reporting only significant p‑values without effect sizes
• Using appropriate sample size, randomization, and blinding with correct statistical tests
• Pooling all data without group comparisons
• Ignoring variability and reporting single animal data

Correct Answer: Using appropriate sample size, randomization, and blinding with correct statistical tests

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