Herbs in hair care focusing on henna and amla are essential topics for B.Pharm students studying phytopharmacology and cosmetology. This introduction covers botanical identity, principal bioactive compounds (lawsone, ascorbic acid, tannins, emblicanin), mechanisms of action (keratin binding, antioxidant and possible 5‑alpha reductase inhibition), extraction and formulation principles, analytical markers (HPTLC, HPLC, Folin–Ciocalteu), safety concerns (contact dermatitis, black henna/PPD adulteration), and stability/quality control of herbal hair preparations. Understanding these aspects links pharmacognosy, pharmaceutics, and regulatory considerations for safe, effective herbal hair-care products. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the botanical name of henna commonly used in hair dyeing?
- Lawsonia inermis
- Phyllanthus emblica
- Azadirachta indica
- Hibiscus rosa-sinensis
Correct Answer: Lawsonia inermis
Q2. Which major pigment in henna is responsible for dyeing hair by binding to keratin?
- Emblicanin A
- Lawsone (2‑hydroxy‑1,4‑naphthoquinone)
- Ascorbic acid
- Quercetin
Correct Answer: Lawsone (2‑hydroxy‑1,4‑naphthoquinone)
Q3. What is the primary botanical name used for amla in pharmacognosy?
- Lawsonia inermis
- Phyllanthus emblica (syn. Emblica officinalis)
- Glycyrrhiza glabra
- Calendula officinalis
Correct Answer: Phyllanthus emblica (syn. Emblica officinalis)
Q4. Which class of compounds in amla contributes most to its strong antioxidant activity?
- Naphthoquinones
- Ascorbic acid and polyphenols (tannins, gallic acid)
- Alkaloids
- Saponins exclusively
Correct Answer: Ascorbic acid and polyphenols (tannins, gallic acid)
Q5. How does lawsone interact with hair proteins to produce dyeing?
- It forms ionic bonds with keratin sulfates
- It deposits as a particulate pigment without chemical bonding
- It reacts covalently with nucleophilic amino acid residues of keratin (Michael‑type addition)
- It chelates metal ions in hair to change color
Correct Answer: It reacts covalently with nucleophilic amino acid residues of keratin (Michael‑type addition)
Q6. Which analytical marker is commonly used for henna quality control by HPTLC/HPLC?
- Lawsone
- Emblicanin A
- Curcumin
- Geraniol
Correct Answer: Lawsone
Q7. Which assay is routinely used to estimate total phenolic content in amla extracts?
- Folin–Ciocalteu reagent assay
- Biuret test
- Anthrone test
- Salkowski test
Correct Answer: Folin–Ciocalteu reagent assay
Q8. Black henna reactions are often due to the addition of which harmful adulterant?
- Paraben
- Para‑phenylenediamine (PPD)
- Ascorbic acid
- Lawsone
Correct Answer: Para‑phenylenediamine (PPD)
Q9. Which property of amla extract supports its use in preventing premature graying of hair?
- Oxidative bleaching of melanin
- Antioxidant protection of melanocytes and melanin stability
- High surfactant content for cleansing
- Chelation of hair calcium
Correct Answer: Antioxidant protection of melanocytes and melanin stability
Q10. What is an important stability concern when formulating aqueous henna pastes for commercial products?
- Excessive protein denaturation of hair in jar
- Microbial growth and degradation of lawsone
- Formation of nitrogen gas
- Spontaneous polymerization to insoluble glue
Correct Answer: Microbial growth and degradation of lawsone
Q11. Which solvent system is most appropriate for extracting both hydrophilic vitamin C and polyphenols from amla?
- Nonpolar solvent such as hexane
- Aqueous or hydroalcoholic (water–ethanol) extraction
- Pure chloroform
- Supercritical CO2 without modifier
Correct Answer: Aqueous or hydroalcoholic (water–ethanol) extraction
Q12. Which in vitro test is commonly used to assess antioxidant capacity of amla extracts?
- DPPH free‑radical scavenging assay
- Gram staining
- Dragendorff’s reagent
- Kjeldahl nitrogen estimation
Correct Answer: DPPH free‑radical scavenging assay
Q13. Which hair formulation benefit is attributed to tannins in henna and amla?
- Strong surfactant foaming
- Protein precipitation and astringent conditioning effect on hair cuticle
- Acting as primary preservative
- Providing UV absorption as sunscreen
Correct Answer: Protein precipitation and astringent conditioning effect on hair cuticle
Q14. Which mechanism is proposed for amla’s potential to support hair growth?
- Topical keratin hydrolysis
- Reduction of oxidative stress and possible inhibition of 5‑alpha reductase
- Direct stimulation of sebaceous gland hyperactivity
- Deposition of insoluble pigments that mechanically thicken hair
Correct Answer: Reduction of oxidative stress and possible inhibition of 5‑alpha reductase
Q15. For a B.Pharm student designing an HPTLC method for henna, which mobile phase component is likely useful to separate lawsone?
- Nonpolar hexane only
- Mixture of ethyl acetate, toluene and formic acid in suitable ratio
- Pure water
- Acetone alone
Correct Answer: Mixture of ethyl acetate, toluene and formic acid in suitable ratio
Q16. Which adverse effect is most commonly associated with topical henna and amla preparations?
- Systemic hepatic failure
- Contact dermatitis and allergic reactions
- Renal toxicity after topical use
- Immediate anaphylactic shock in all users
Correct Answer: Contact dermatitis and allergic reactions
Q17. Which excipient type improves penetration of aqueous amla actives into hair follicles in topical formulations?
- Nonvolatile oils and penetration enhancers (e.g., propylene glycol)
- Strong oxidizing agents
- High levels of particulate clay
- Strong acids for keratin hydrolysis
Correct Answer: Nonvolatile oils and penetration enhancers (e.g., propylene glycol)
Q18. Which simple quality control test helps detect PPD adulteration in black henna?
- pH paper test
- Thin‑layer chromatography / colorimetric tests for aromatic amines
- Froth test for saponins
- Benedict’s test for reducing sugars
Correct Answer: Thin‑layer chromatography / colorimetric tests for aromatic amines
Q19. Which factor increases the rate and intensity of henna color development on hair?
- Short contact time (5 minutes)
- Longer contact time, higher concentration, warmth
- Use of strong reducing agents
- Extremely acidic pH below 2
Correct Answer: Longer contact time, higher concentration, warmth
Q20. Which statement about the photostability of lawsone is correct for formulation design?
- Lawsone is completely photostable and needs no protection
- Lawsone can photodegrade so antioxidants and opaque packaging help stability
- Lawsone requires high UV exposure to activate dyeing
- Lawsone is a gas at room temperature and volatile
Correct Answer: Lawsone can photodegrade so antioxidants and opaque packaging help stability
Q21. Which analytical technique best quantifies ascorbic acid content in fresh amla?
- Gas chromatography without derivatization
- HPLC with UV detection
- Kjeldahl method
- Atomic absorption spectroscopy
Correct Answer: HPLC with UV detection
Q22. Which formulation form is traditionally used to apply henna to hair in pharmaceutics and cosmetology?
- Dry compressed tablet
- Freshly prepared aqueous paste from powdered henna leaves
- Inhalation aerosol
- Parenteral injection
Correct Answer: Freshly prepared aqueous paste from powdered henna leaves
Q23. What precaution should pharmacists advise before using henna hair products to minimize allergic risk?
- Avoid any patch test because it wastes product
- Perform a small patch test 48 hours before full application
- Mix henna with PPD to reduce allergy
- Apply to irritated scalp to build tolerance
Correct Answer: Perform a small patch test 48 hours before full application
Q24. Which compound group in amla contributes to antimicrobial effects useful in hair care formulations?
- Vitamins only
- Polyphenols and tannins
- Inorganic salts like sodium chloride
- Saturated hydrocarbons
Correct Answer: Polyphenols and tannins
Q25. Which regulatory consideration is most relevant when marketing a henna hair dye product?
- Labeling of botanical source, concentration of active marker, and warnings about PPD
- Requirement for injectable sterile grade
- Mandatory inclusion of synthetic preservatives only
- No requirement for stability testing
Correct Answer: Labeling of botanical source, concentration of active marker, and warnings about PPD
Q26. Which chromatographic profile peak would indicate presence of emblicanin in amla extract?
- A peak matching emblicanin reference standard in HPLC/HPTLC
- A single peak at retention time zero
- No peaks; emblicanin is not detectable chromatographically
- Only volatile peaks in GC profile
Correct Answer: A peak matching emblicanin reference standard in HPLC/HPTLC
Q27. Which effect does combining amla with oils (e.g., coconut oil) in formulations provide?
- Increased oxidative degradation of actives
- Enhanced conditioning, antioxidant delivery and scalp moisturization
- Complete removal of tannins
- Conversion of ascorbic acid to insoluble salts
Correct Answer: Enhanced conditioning, antioxidant delivery and scalp moisturization
Q28. Which preservative strategy is appropriate for aqueous herbal hair tonics containing amla?
- No preservative if bottled in clear glass
- Use broad‑spectrum preservatives plus good pH control and low water activity where possible
- Add sugar to 50% as preservative
- Heat to 200°C to sterilize final product
Correct Answer: Use broad‑spectrum preservatives plus good pH control and low water activity where possible
Q29. Which in vivo endpoint is most appropriate in a clinical trial assessing henna’s hair color efficacy?
- Systemic blood pressure change
- Objective colorimetric measurement of hair color intensity and colorfastness
- Urinary lawsone levels only
- Height increase of subjects
Correct Answer: Objective colorimetric measurement of hair color intensity and colorfastness
Q30. Which statement best summarizes the integrated role of henna and amla in evidence‑based herbal hair care?
- They are interchangeable with no distinct activities
- Henna provides natural dyeing and conditioning via lawsone; amla offers antioxidant, conditioning and potential anti‑hair loss actions via polyphenols and vitamin C, requiring standardized extracts and safety evaluation
- Both are toxic and have no cosmetic value
- They function solely as synthetic preservative substitutes
Correct Answer: Henna provides natural dyeing and conditioning via lawsone; amla offers antioxidant, conditioning and potential anti‑hair loss actions via polyphenols and vitamin C, requiring standardized extracts and safety evaluation
