Toxicity studies as per OECD guidelines for herbal products MCQs With Answer

Toxicity studies as per OECD guidelines for herbal products MCQs With Answer

This quiz collection is designed for M.Pharm students studying Advanced Pharmacognosy-II to deepen understanding of toxicity testing of herbal products following OECD guidelines. It covers acute, subacute, subchronic and chronic toxicity protocols, genotoxicity assays, reproductive and developmental studies, toxicokinetics, study design considerations such as dose selection, limit tests, GLP, and interpretation of NOAEL/LOAEL. Questions emphasize practical application for herbal extracts — including test item characterization, route of administration, satellite groups, humane endpoints and reporting standards — to prepare students for research, regulatory submissions and critical appraisal of preclinical toxicology data.

Q1. Which OECD test guideline is commonly used for acute oral toxicity using the up-and-down procedure suitable for minimizing animal use in herbal extract testing?

• OECD 420 Fixed Dose Procedure
• OECD 425 Up-and-Down Procedure
• OECD 423 Acute Toxic Class Method
• OECD 408 90-Day Oral Toxicity Study

Correct Answer: OECD 425 Up-and-Down Procedure

Q2. In a 28-day repeated dose toxicity study of a herbal extract (OECD 407), which parameter is most critical for establishing the NOAEL?

• Appearance and colour of dosing solution
• Detailed histopathology of target organs
• Daily body weight measurement only
• Supplier certificate of raw herb

Correct Answer: Detailed histopathology of target organs

Q3. Which OECD guideline provides the standard for 90-day (subchronic) oral toxicity studies in rodents?

• OECD 420
• OECD 408
• OECD 407
• OECD 401

Correct Answer: OECD 408

Q4. For genotoxicity assessment of an herbal product, which in vitro test is typically performed first as a screening assay under OECD guidelines?

• OECD 471 Bacterial Reverse Mutation (Ames) Test
• OECD 486 In Vitro Mammalian Cell Micronucleus Test
• OECD 473 In Vivo Chromosomal Aberration Test
• OECD 408 Subchronic Toxicity

Correct Answer: OECD 471 Bacterial Reverse Mutation (Ames) Test

Q5. In OECD toxicity studies of herbal extracts, what is the purpose of conducting a limit test?

• To determine maximum tolerated concentration in humans
• To assess toxicity at a single high dose when no adverse effects are anticipated
• To compare two extraction methods
• To replace GLP requirements

Correct Answer: To assess toxicity at a single high dose when no adverse effects are anticipated

Q6. Which parameter is essential to report for the test item in OECD guideline studies for herbal products?

• Colour of the lab coat worn by the technician
• Detailed characterization including phytochemical profile and batch-to-batch consistency
• Retail price of the herbal product
• Number of pages in the supplier brochure

Correct Answer: Detailed characterization including phytochemical profile and batch-to-batch consistency

Q7. Which OECD guideline addresses toxicokinetic studies that help interpret systemic exposure and dose selection in toxicity testing?

• OECD 417 Toxicokinetics
• OECD 429 Skin Sensitisation
• OECD 425 Acute Oral Toxicity
• OECD 471 Ames Test

Correct Answer: OECD 417 Toxicokinetics

Q8. For dermal toxicity testing of an herbal formulation, which route and guideline are most appropriate?

• Oral administration under OECD 408
• Topical/dermal administration under OECD 402 Acute Dermal Toxicity
• Inhalation exposure under OECD 403
• Intravenous injection under OECD 410

Correct Answer: Topical/dermal administration under OECD 402 Acute Dermal Toxicity

Q9. Which OECD guideline covers in vitro skin irritation tests that can be used for topical herbal products to reduce animal use?

• OECD 439 In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method
• OECD 420 Fixed Dose Procedure
• OECD 408 90-Day Study
• OECD 474 In Vivo Micronucleus Test

Correct Answer: OECD 439 In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method

Q10. In reproductive and developmental toxicity testing of herbal extracts, which guideline series provides relevant test methods?

• OECD TG 414 Prenatal Developmental Toxicity Study and TG 416 Two-Generation Reproduction Toxicity
• OECD 471 Ames Test only
• OECD 407 28-Day Study only
• OECD 423 Acute Toxic Class only

Correct Answer: OECD TG 414 Prenatal Developmental Toxicity Study and TG 416 Two-Generation Reproduction Toxicity

Q11. What is the primary regulatory significance of determining NOAEL in OECD toxicity studies of herbal products?

• To calculate therapeutic dose in humans without uncertainty factors
• To establish a reference point for deriving safe human exposure limits using uncertainty factors
• To determine manufacturing cost
• To certify herbal purity

Correct Answer: To establish a reference point for deriving safe human exposure limits using uncertainty factors

Q12. Which in vivo assay under OECD guidelines is commonly used to detect clastogenic and aneugenic effects in mammalian bone marrow?

• OECD 471 Ames Test
• OECD 474 Mammalian Erythrocyte Micronucleus Test
• OECD 429 Skin Sensitisation Test
• OECD 439 Skin Irritation Test

Correct Answer: OECD 474 Mammalian Erythrocyte Micronucleus Test

Q13. When designing an OECD-compliant subchronic study for a herbal extract, why are satellite groups used?

• To increase the number of histology slides
• To allow recovery assessment after treatment cessation for reversibility of effects
• To provide extra animals for breeding
• To test a different formulation not specified in the protocol

Correct Answer: To allow recovery assessment after treatment cessation for reversibility of effects

Q14. For regulatory submissions, Good Laboratory Practice (GLP) is required because it ensures which of the following for OECD toxicity studies?

• Lower cost of the study
• Standardization, traceability, data integrity and reproducibility of study data
• Faster publication in journals
• Exemption from ethical review

Correct Answer: Standardization, traceability, data integrity and reproducibility of study data

Q15. In the context of herbal product toxicity testing, which approach is recommended by OECD for reducing animal use while still generating necessary safety data?

• Use highest possible dose without pilot studies
• Apply weight-of-evidence, read-across, in vitro alternatives and tiered testing strategies
• Exclude histopathology to save animals
• Test only on one sex of animals

Correct Answer: Apply weight-of-evidence, read-across, in vitro alternatives and tiered testing strategies

Q16. Which factor is most important when preparing a dosing solution of a herbal extract for an OECD toxicity study?

• Smell of the solution
• Stability and homogeneity of the test item in the vehicle across the dosing period
• Colour matching with control vehicle
• Using distilled water only regardless of solubility

Correct Answer: Stability and homogeneity of the test item in the vehicle across the dosing period

Q17. The Ames test (OECD 471) requires metabolic activation (S9 mix) for herbal extracts primarily to:

• Enhance bacterial growth
• Simulate mammalian metabolic conversion to detect promutagens
• Reduce solvent effects
• Stain colonies for easier counting

Correct Answer: Simulate mammalian metabolic conversion to detect promutagens

Q18. Which observation in a 90-day oral toxicity study would most directly indicate hepatotoxicity from a herbal extract?

• Increased kidney weight only
• Elevated serum ALT/AST levels and histopathological lesions in the liver
• Change in fur colour
• Altered cage activity during night only

Correct Answer: Elevated serum ALT/AST levels and histopathological lesions in the liver

Q19. During OECD guideline studies, humane endpoints are important because they:

• Ensure data variability is maximized
• Allow early euthanasia to minimize animal suffering while preserving scientific objectives
• Require additional animals to be used
• Are optional recommendations with no impact on study design

Correct Answer: Allow early euthanasia to minimize animal suffering while preserving scientific objectives

Q20. For an herbal product with multiple constituents, which toxicological data approach is most appropriate under OECD recommendations?

• Test only the major constituent and ignore the extract
• Characterize the whole extract, test the extract itself and use component data for read-across where justified
• Assume traditional use equates to safety and skip testing
• Test each constituent separately without studying the whole extract

Correct Answer: Characterize the whole extract, test the extract itself and use component data for read-across where justified

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