Toxicity screening of herbal cosmetics MCQs With Answer

Introduction:

This quiz compilation focuses on toxicity screening of herbal cosmetics tailored for M.Pharm students. It covers essential concepts such as in vitro and in vivo toxicological assays, dermal irritation and sensitization testing, phototoxicity, genotoxicity, and safety assessment strategies specific to herbal ingredients. Emphasis is placed on regulatory guidelines, interpretation of hazard and risk, biomarkers, and common contaminants (heavy metals, pesticides, mycotoxins) that influence safety. These MCQs are framed to deepen understanding of experimental design, OECD test guidelines, data interpretation (NOAEL, LD50, IC50), and best practices for standardization and quality control of herbal cosmetic preparations used in preclinical evaluation.

Q1. Which in vitro assay is commonly used to assess skin irritation potential of cosmetic formulations as an alternative to the Draize rabbit test?

• Franz diffusion cell permeation test
• Keratinocyte (KeratinoSens) or reconstructed human epidermis (RHE) models
• Local lymph node assay (LLNA)
• Ames bacterial reverse mutation test

Correct Answer: Keratinocyte (KeratinoSens) or reconstructed human epidermis (RHE) models

Q2. The Local Lymph Node Assay (LLNA) primarily assesses which aspect of dermal toxicity?

• Acute dermal irritation
• Skin sensitization via lymphocyte proliferation
• Phototoxicity upon UV exposure
• Transdermal permeation rate

Correct Answer: Skin sensitization via lymphocyte proliferation

Q3. In toxicity screening, NOAEL stands for which of the following?

• Normal Observed Adverse Exposure Limit
• No Observed Adverse Effect Level
• Non-Observable Aqueous Effect Limit
• New Observational Active Endpoint Level

Correct Answer: No Observed Adverse Effect Level

Q4. Which OECD test guideline is widely used for assessing acute dermal toxicity in animals?

• OECD TG 404
• OECD TG 402
• OECD TG 471
• OECD TG 487

Correct Answer: OECD TG 402

Q5. Phototoxicity of herbal cosmetics, particularly those containing furocoumarins, is best screened by which in vitro method?

• 3T3 Neutral Red Uptake (NRU) phototoxicity test
• Micronucleus assay in lymphocytes
• Hepatocyte metabolic stability test
• Transdermal flux by Franz cell

Correct Answer: 3T3 Neutral Red Uptake (NRU) phototoxicity test

Q6. Which test is primarily used to detect mutagenic potential of herbal extracts at the bacterial level?

• Ames (bacterial reverse mutation) test
• Comet assay in keratinocytes
• Local lymph node assay
• In vitro skin irritation using RHE

Correct Answer: Ames (bacterial reverse mutation) test

Q7. For topical herbal cosmetics, the Margin of Safety (MOS) is calculated by comparing which two values?

• Maximum usage concentration and LD50
• Systemic exposure dose and therapeutic index
• No Observed Adverse Effect Level (NOAEL) and estimated human exposure
• IC50 and EC50 values

Correct Answer: No Observed Adverse Effect Level (NOAEL) and estimated human exposure

Q8. Which contaminant class in herbal raw materials is particularly associated with hepatotoxicity and requires targeted screening?

• Short-chain fatty acids
• Pyrrolizidine alkaloids
• Non-ionic surfactants
• Phthalate esters

Correct Answer: Pyrrolizidine alkaloids

Q9. The Draize test historically assessed which endpoint in rabbits?

• Ocular irritation and scoring of corneal/conjunctival damage
• Systemic toxicity from oral administration
• Mutagenicity in bone marrow
• Dermal sensitization using lymph node proliferation

Correct Answer: Ocular irritation and scoring of corneal/conjunctival damage

Q10. Which parameter is most relevant when evaluating dermal absorption of an herbal active using Franz diffusion cells?

• Vapor pressure of the compound
• Permeation flux (ng/cm2/hr) across excised skin
• Systemic clearance in rodents
• Melting point of the active component

Correct Answer: Permeation flux (ng/cm2/hr) across excised skin

Q11. Which assay is suitable for detecting cytotoxicity of herbal cosmetic extracts in cultured mammalian cells?

• MTT or XTT cell viability assays
• Gas chromatography-mass spectrometry (GC-MS)
• Headspace analysis
• Skin colorimeter measurement

Correct Answer: MTT or XTT cell viability assays

Q12. The presence of heavy metals like lead and mercury in herbal cosmetics is primarily assessed by which analytical technique?

• High performance liquid chromatography (HPLC)
• Inductively coupled plasma mass spectrometry (ICP-MS)
• ELISA for proteins
• Polarimetry

Correct Answer: Inductively coupled plasma mass spectrometry (ICP-MS)

Q13. Which guideline or committee provides opinions on safety of cosmetic ingredients in the European Union?

• ICH (International Council for Harmonisation)
• SCCS (Scientific Committee on Consumer Safety)
• ICH Q1A Stability
• FDA Center for Devices and Radiological Health

Correct Answer: SCCS (Scientific Committee on Consumer Safety)

Q14. For assessing genotoxicity in mammalian cells, which assay detects DNA strand breaks at the single cell level?

• Micronucleus assay
• Comet assay (single cell gel electrophoresis)
• Ames test
• LLNA

Correct Answer: Comet assay (single cell gel electrophoresis)

Q15. Which of the following is a key concern with essential oils in topical herbal cosmetics?

• High ionic strength altering pH
• Potential phototoxicity due to furocoumarins and psoralens
• Inability to penetrate the stratum corneum
• Absence of volatile constituents

Correct Answer: Potential phototoxicity due to furocoumarins and psoralens

Q16. The preservative efficacy test (challenge test) for cosmetics evaluates which factor?

• Ability of preservative system to prevent microbial growth during product use
• Rate of skin absorption of preservatives
• Volatility of the preservative under vacuum
• Partition coefficient between oil and water phases

Correct Answer: Ability of preservative system to prevent microbial growth during product use

Q17. Which statement about batch-to-batch variability in herbal extracts is most accurate for toxicity assessment?

• Variability is negligible after extraction and need not be controlled
• Standardization of marker compounds and phytochemical profiling is essential to ensure reproducible safety data
• Only the solvent used matters for toxicity, not the extract composition
• Biological assays cannot detect differences from variability

Correct Answer: Standardization of marker compounds and phytochemical profiling is essential to ensure reproducible safety data

Q18. When evaluating systemic toxicity after repeated dermal exposure in animals, which clinical pathology parameters are typically monitored?

• Blood glucose only
• Hematology (RBC, WBC), liver enzymes (ALT, AST), and renal markers (creatinine, BUN)
• Only skin histology at application site
• Electrolytes only

Correct Answer: Hematology (RBC, WBC), liver enzymes (ALT, AST), and renal markers (creatinine, BUN)

Q19. Which regulatory concept requires that cosmetic ingredients demonstrate a sufficient margin between safe exposure and observed adverse effect levels?

• Good Manufacturing Practice (GMP)
• Margin of Safety (MOS)
• Bioequivalence Index (BEI)
• Production batch certification

Correct Answer: Margin of Safety (MOS)

Q20. In assessing genotoxic impurities in herbal cosmetics, which approach provides the most conservative safety evaluation?

• Ignoring low-level impurities due to natural origin
• Applying threshold of toxicological concern (TTC) and conducting appropriate genotoxicity tests if above TTC
• Relying solely on historical human use without testing
• Measuring only total organic carbon (TOC)

Correct Answer: Applying threshold of toxicological concern (TTC) and conducting appropriate genotoxicity tests if above TTC

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