Flaxseeds are a nutrient-dense botanical widely studied for their medicinal uses and health benefits relevant to pharmacy practice. Rich in alpha-linolenic acid (ALA), lignans (e.g., secoisolariciresinol diglucoside, SDG), mucilage, and dietary fiber, flaxseed offers lipid-lowering, antiplatelet, anti-inflammatory, glycemic-modulating, and laxative effects. Understanding pharmacognosy, extraction methods, formulations (oil, ground seed, mucilage, capsules), pharmacokinetics, analytical assays (GC, HPLC), clinical evidence, adverse effects, and drug interactions is essential for B. Pharm students to counsel patients and evaluate research. This concise overview emphasizes mechanisms—limited ALA conversion, enterolignan formation by gut microbiota, and bile-acid binding—plus quality control and dosing considerations. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which constituent is the primary omega-3 fatty acid in flaxseeds?
- Alpha-linolenic acid (ALA)
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
- Linoleic acid
Correct Answer: Alpha-linolenic acid (ALA)
Q2. Which lignan is the major phenolic compound in flaxseed?
- Secoisolariciresinol diglucoside (SDG)
- Matairesinol
- Enterolactone
- Enterodiol
Correct Answer: Secoisolariciresinol diglucoside (SDG)
Q3. What is a primary mechanism by which flaxseed lowers serum cholesterol?
- Inhibition of HMG-CoA reductase in the liver
- Binding bile acids in the intestine and increasing their excretion
- Direct removal of cholesterol by gut absorption
- Enhancement of cholesterol synthesis
Correct Answer: Binding bile acids in the intestine and increasing their excretion
Q4. Which statement about conversion of ALA to EPA/DHA in humans is correct?
- ALA converts to EPA/DHA with high efficiency (>50%)
- ALA conversion to EPA/DHA is limited and variable (<10% to EPA, even lower to DHA)
- ALA is directly converted to arachidonic acid
- ALA is not metabolized and is excreted unchanged
Correct Answer: ALA conversion to EPA/DHA is limited and variable (<10% to EPA, even lower to DHA)
Q5. Flaxseed lignans are bioactivated in the gut primarily by:
- Hepatic enzymes
- Acid hydrolysis in the stomach
- Gut microbiota converting SDG to enterolignans
- Pancreatic lipases
Correct Answer: Gut microbiota converting SDG to enterolignans
Q6. Which analytical technique is most suitable for profiling fatty acids in flaxseed oil?
- High-performance liquid chromatography (HPLC) with UV detection
- Gas chromatography with flame ionization detection (GC-FID)
- Colorimetric assay
- Infrared spectroscopy
Correct Answer: Gas chromatography with flame ionization detection (GC-FID)
Q7. Which quality-control parameter indicates primary oxidation (rancidity) of flaxseed oil?
- Acid value
- Peroxide value
- Iodine value
- Saponification value
Correct Answer: Peroxide value
Q8. Flaxseed mucilage is commonly used in pharmaceutical formulations as a:
- Preservative
- Binder and suspending agent (excipient)
- Systemic antiseptic
- Antioxidant additive
Correct Answer: Binder and suspending agent (excipient)
Q9. A recognized potential adverse effect or interaction with high flaxseed intake is:
- Severe hepatotoxicity
- Increased bleeding risk with anticoagulants
- Permanent renal damage
- Acute pancreatitis
Correct Answer: Increased bleeding risk with anticoagulants
Q10. How does flaxseed primarily affect postprandial blood glucose?
- Increases glucose absorption
- Reduces postprandial glucose by slowing carbohydrate absorption through viscous fiber
- Stimulates pancreatic beta-cell proliferation
- Blocks glucose transporters in muscle
Correct Answer: Reduces postprandial glucose by slowing carbohydrate absorption through viscous fiber
Q11. For maximal bioavailability of ALA from flaxseed, which form is preferred?
- Whole intact seeds
- Ground flaxseed or flaxseed oil
- Flaxseed hulls only
- Raw seed pods
Correct Answer: Ground flaxseed or flaxseed oil
Q12. A commonly recommended therapeutic daily dose range of ground flaxseed used in clinical studies is:
- 1–2 g
- 5–10 g
- 10–30 g
- 50–100 g
Correct Answer: 10–30 g
Q13. Regarding use in pregnancy, current guidance for flaxseed intake is:
- Universally recommended at high doses
- Use with caution or avoid high doses due to phytoestrogen content
- Required for fetal neurodevelopment
- No restrictions; completely safe at any dose
Correct Answer: Use with caution or avoid high doses due to phytoestrogen content
Q14. The laxative action of flaxseed is mainly due to:
- A stimulant effect on enteric nerves
- Bulk-forming fiber increasing fecal bulk and water retention
- Osmotic salts released from seeds
- Direct secretory action on colonic mucosa
Correct Answer: Bulk-forming fiber increasing fecal bulk and water retention
Q15. Which compound in flaxseed contributes significantly to its antioxidant activity?
- Sodium lignate
- Secoisolariciresinol diglucoside (SDG)
- Cholesterol
- Trans fats
Correct Answer: Secoisolariciresinol diglucoside (SDG)
Q16. Which drug class is most likely to interact clinically with flaxseed supplementation?
- Proton pump inhibitors
- Anticoagulants such as warfarin
- Beta-adrenergic blockers
- Loop diuretics
Correct Answer: Anticoagulants such as warfarin
Q17. Ideal storage for flaxseed oil to minimize oxidation is:
- Room temperature in a clear bottle
- Refrigerated in a dark, airtight container
- Exposed to light on a warm shelf
- Stored near heat sources for stability
Correct Answer: Refrigerated in a dark, airtight container
Q18. Which parameter measures the degree of unsaturation in flaxseed oil?
- Peroxide value
- Iodine value
- Acid value
- Moisture content
Correct Answer: Iodine value
Q19. Clinical evidence supports that flaxseed supplementation typically produces which effect on LDL cholesterol?
- No change in LDL cholesterol
- Modest reduction in LDL cholesterol
- More than 50% reduction in LDL cholesterol
- Increase in LDL cholesterol
Correct Answer: Modest reduction in LDL cholesterol
Q20. Enterolactone, a metabolite of flax lignans, exhibits which biological activity?
- Mineralocorticoid receptor agonism
- Phytoestrogenic activity (estrogenic/anti-estrogenic effects)
- Strong pro-inflammatory signaling
- Direct antimicrobial killing
Correct Answer: Phytoestrogenic activity (estrogenic/anti-estrogenic effects)
Q21. Which extraction method preserves ALA content best for nutritional flaxseed oil?
- High-temperature solvent extraction
- Cold-pressing (mechanical pressing at low temperature)
- Prolonged steam distillation
- Superheated water extraction
Correct Answer: Cold-pressing (mechanical pressing at low temperature)
Q22. Which patient group has been commonly targeted in clinical trials of flaxseed for benefit?
- Patients with hyperlipidemia
- Patients with acute bacterial infections
- Patients requiring opioid analgesia
- Patients with stage IV cancer only
Correct Answer: Patients with hyperlipidemia
Q23. Which flaxseed component primarily contributes to its laxative (bowel-regulating) action?
- Lignans
- Mucilage (soluble fiber)
- Trace minerals
- Protein fraction
Correct Answer: Mucilage (soluble fiber)
Q24. A biochemical reason for poor conversion of ALA to long-chain omega-3s is:
- Excessive pancreatic lipase activity
- Low conversion efficiency due to competition with omega-6 fatty acid metabolism
- Immediate renal excretion of ALA
- Lack of dietary carbohydrates
Correct Answer: Low conversion efficiency due to competition with omega-6 fatty acid metabolism
Q25. Which analytical technique is most appropriate for quantifying SDG lignan content in flaxseed samples?
- Gas chromatography-mass spectrometry (GC-MS) for non-derivatized lignans
- High-performance liquid chromatography (HPLC)
- Simple pH titration
- Direct UV spectrophotometry without separation
Correct Answer: High-performance liquid chromatography (HPLC)
Q26. A common tolerability issue with high intake of flaxseed is:
- Gastrointestinal discomfort such as bloating and gas
- Severe hypertension
- Acute vision loss
- Marked bradycardia
Correct Answer: Gastrointestinal discomfort such as bloating and gas
Q27. Flaxseed oil is predominantly composed of which fatty acid class?
- Saturated fatty acids
- Omega-3 polyunsaturated fatty acids
- Trans fatty acids
- Medium-chain triglycerides
Correct Answer: Omega-3 polyunsaturated fatty acids
Q28. For standardization of flaxseed nutraceuticals, which parameter is commonly measured?
- Secoisolariciresinol diglucoside (SDG) content
- Vitamin C content
- Mercury concentration
- Fungal spore count only
Correct Answer: Secoisolariciresinol diglucoside (SDG) content
Q29. Topical application of flaxseed oil is mainly used for:
- Antiseptic wound sterilization
- Emollient and skin barrier repair
- Photosensitization in phototherapy
- Hair depigmentation
Correct Answer: Emollient and skin barrier repair
Q30. Which statement about flaxseed is FALSE?
- Flaxseed contains alpha-linolenic acid (ALA)
- Flaxseed lignans are converted by gut bacteria to enterolignans
- Whole flaxseed provides maximal bioavailability of ALA
- Flaxseed fiber can help lower serum cholesterol
Correct Answer: Whole flaxseed provides maximal bioavailability of ALA
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
Mail- Sachin@pharmacyfreak.com