Introduction: Soyabean (soybean) is a versatile medicinal plant and nutrient-dense legume widely studied for its medicinal uses and health benefits. Rich in isoflavones (genistein, daidzein), high-quality soy protein, saponins, lecithin and essential fatty acids, soy exerts lipid-lowering, cardioprotective, antioxidant, anti-inflammatory and bone-preserving effects. In pharmacy practice, soy derivatives are important as nutraceuticals, excipients and standardized herbal extracts; understanding phytochemistry, extraction, standardization, safety, drug interactions and clinical evidence is essential for B. Pharm students. This review-focused MCQ set emphasizes pharmacology, therapeutic applications, adverse effects and formulation aspects of soyabean to build critical thinking and exam preparedness. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which is the principal isoflavone in soyabean associated with many pharmacological effects?
- Equol
- Glycitein
- Genistein
- Daidzein
Correct Answer: Genistein
Q2. Soy isoflavones are classified pharmacologically as which of the following?
- Synthetic estrogens
- Phytoestrogens
- Steroidal androgens
- Peptidic growth factors
Correct Answer: Phytoestrogens
Q3. Which pair represents the major storage proteins in soybean relevant to nutritional and formulation studies?
- Albumin and globulin
- Glycinin and beta-conglycinin
- Casein and whey
- Legumin and vicilin
Correct Answer: Glycinin and beta-conglycinin
Q4. The lipid-lowering effect of soy protein is primarily attributed to which mechanism?
- Direct inhibition of pancreatic lipase
- Activation of hepatic LDL receptor expression
- Decreasing intestinal triglyceride absorption by micelle disruption
- Blocking dietary cholesterol absorption by forming insoluble complexes
Correct Answer: Activation of hepatic LDL receptor expression
Q5. Genistein shows higher binding affinity for which estrogen receptor subtype, influencing selective tissue effects?
- ERα (Estrogen Receptor alpha)
- ERβ (Estrogen Receptor beta)
- GPR30 (G-protein coupled estrogen receptor)
- Progesterone receptor
Correct Answer: ERβ (Estrogen Receptor beta)
Q6. Fermentation of soybean (e.g., tempeh, miso) commonly results in which pharmacologically relevant change?
- Conversion of aglycones to glycosides, reducing bioavailability
- Increase in isoflavone glycosides and decrease in aglycones
- Increase in isoflavone aglycones and reduced allergenicity
- Complete loss of isoflavones and proteins
Correct Answer: Increase in isoflavone aglycones and reduced allergenicity
Q7. Soy lecithin is widely used in pharmaceutical formulations primarily as what?
- A preservative
- An emulsifier
- An antimicrobial agent
- A colouring agent
Correct Answer: An emulsifier
Q8. Which patient group is at increased risk of thyroid dysfunction when consuming large amounts of unprocessed soy products?
- Patients with iodine deficiency
- Patients with hypertension
- Patients with hyperlipidemia
- Patients with vitamin D toxicity
Correct Answer: Patients with iodine deficiency
Q9. Clinical evidence most strongly supports soy isoflavone supplementation for which menopausal symptom?
- Prevention of ovarian cysts
- Significant cure of osteoporosis within weeks
- Modest reduction in frequency and severity of hot flashes
- Complete restoration of menstrual cycles
Correct Answer: Modest reduction in frequency and severity of hot flashes
Q10. Which of the following is a clear contraindication for using soy-based supplements?
- History of peanut allergy
- Confirmed soy allergy (IgE-mediated)
- Mild seasonal allergic rhinitis
- Previous gallstone surgery
Correct Answer: Confirmed soy allergy (IgE-mediated)
Q11. One anticancer mechanism attributed to genistein is inhibition of which cellular enzyme/pathway?
- DNA-dependent RNA polymerase II
- Non-receptor tyrosine kinases (tyrosine kinase inhibition)
- Na+/K+ ATPase
- Acetylcholinesterase
Correct Answer: Non-receptor tyrosine kinases (tyrosine kinase inhibition)
Q12. Typical supplemental doses of total isoflavones studied for menopausal symptom relief are commonly reported in which range?
- 1–5 mg/day
- 10–20 mg/day
- 40–80 mg/day
- 500–1000 mg/day
Correct Answer: 40–80 mg/day
Q13. Regarding protein quality scoring, soy protein isolate typically has which PDCAAS (Protein Digestibility-Corrected Amino Acid Score) characteristic?
- Very low, below 0.3
- Moderate, around 0.5
- High, close to 1.0
- Undefined, cannot be determined
Correct Answer: High, close to 1.0
Q14. Soy saponins contribute to which hypocholesterolemic action?
- Increasing endogenous cholesterol synthesis
- Reducing intestinal cholesterol absorption
- Stimulating adipose lipogenesis
- Acting as HMG-CoA reductase agonists
Correct Answer: Reducing intestinal cholesterol absorption
Q15. Which class of soybean constituents primarily contributes to antioxidant activity observed in vitro?
- Isoflavones (e.g., genistein, daidzein)
- Starch polymers
- Simple sugars like sucrose
- Mineral salts
Correct Answer: Isoflavones (e.g., genistein, daidzein)
Q16. Soybean oil is characterized by a high proportion of which type of fatty acid?
- Saturated fatty acids (palmitic dominant)
- Monounsaturated fatty acids (oleic dominant)
- Polyunsaturated fatty acids (linoleic acid dominant)
- Trans fatty acids
Correct Answer: Polyunsaturated fatty acids (linoleic acid dominant)
Q17. For standardization of soy isoflavone extracts in pharmaceutics, which marker compounds are typically quantified?
- Quercetin and kaempferol
- Genistein and daidzein
- Catechin and epicatechin
- Curcumin and demethoxycurcumin
Correct Answer: Genistein and daidzein
Q18. Which anti-nutritional factor in soybean can chelate minerals and reduce their bioavailability?
- Phytic acid (phytate)
- Vitamin C
- Omega-3 fatty acids
- Calcium carbonate
Correct Answer: Phytic acid (phytate)
Q19. Compared to glycoside forms, isoflavone aglycones in soy have which pharmacokinetic advantage?
- Lower intestinal absorption and bioavailability
- Higher molecular weight prevents absorption
- Higher bioavailability due to easier absorption
- Complete resistance to metabolism
Correct Answer: Higher bioavailability due to easier absorption
Q20. Soybean allergy reactions are primarily mediated by which immunological mechanism?
- Type I hypersensitivity (IgE-mediated)
- Type IV hypersensitivity (T-cell mediated)
- Autoimmune T-cell destruction
- Immune complex deposition (Type III)
Correct Answer: Type I hypersensitivity (IgE-mediated)
Q21. Long-term epidemiological studies in East Asian populations suggest habitual soy consumption is associated with what effect on breast cancer risk?
- No effect or increased risk in all cases
- Lifelong consumption associated with reduced breast cancer risk
- Immediate protective effect when started after diagnosis
- Guaranteed prevention of breast cancer
Correct Answer: Lifelong consumption associated with reduced breast cancer risk
Q22. Heat treatment of soybean during processing primarily inactivates which antinutrient to improve protein digestibility?
- Phytic acid
- Trypsin inhibitors
- Isoflavone aglycones
- Vitamin B12
Correct Answer: Trypsin inhibitors
Q23. The presence of trypsin inhibitors in raw soybean leads to which nutritional consequence if not inactivated?
- Enhanced protein digestibility
- Decreased protein digestibility and pancreatic hypertrophy
- Increased vitamin absorption
- Higher carbohydrate bioavailability
Correct Answer: Decreased protein digestibility and pancreatic hypertrophy
Q24. Soy isoflavones can affect drug metabolism by modulating which family of enzymes important in hepatic drug clearance?
- Monoamine oxidases (MAO)
- Cytochrome P450 enzymes (e.g., CYP3A4)
- DNA polymerases
- Acetylcholinesterase
Correct Answer: Cytochrome P450 enzymes (e.g., CYP3A4)
Q25. Which statement about isoflavone forms in fermented versus unfermented soy foods is correct?
- Fermented soy foods have more glycoside-conjugated isoflavones
- Fermented soy foods have increased isoflavone aglycones
- Unfermented soy contains only aglycones
- There is no difference in isoflavone form between fermented and unfermented soy
Correct Answer: Fermented soy foods have increased isoflavone aglycones
Q26. Tempeh, a fermented soybean product used in nutraceuticals, is produced primarily by which microorganism?
- Lactobacillus acidophilus
- Saccharomyces cerevisiae
- Rhizopus oligosporus (mold)
- Bacillus subtilis
Correct Answer: Rhizopus oligosporus (mold)
Q27. After absorption, soy isoflavones are primarily metabolized in the liver by which conjugation pathways before excretion?
- Methylation only
- Glucuronidation and sulfation
- Acetylation only
- Proteolytic cleavage
Correct Answer: Glucuronidation and sulfation
Q28. Soy protein isolate used in pharmaceutical and food formulations is characterized by which protein content?
- Less than 10% protein
- Approximately 30% protein
- Greater than 90% protein
- Only lipids, no protein
Correct Answer: Greater than 90% protein
Q29. The potential bone-protective effect of soy isoflavones is attributed mainly to which property?
- Direct calcium supplementation from isoflavones
- Estrogenic activity that helps reduce bone resorption
- Inhibition of vitamin D synthesis
- Blocking intestinal calcium absorption
Correct Answer: Estrogenic activity that helps reduce bone resorption
Q30. Which analytical technique is most commonly used in pharmaceutics to quantify individual soy isoflavones in extracts?
- Thin layer chromatography without standards
- High-performance liquid chromatography (HPLC) with UV detection
- Gravimetric analysis of total solids
- Simple colorimetric assay for total protein
Correct Answer: High-performance liquid chromatography (HPLC) with UV detection
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