Medicinal uses and health benefits of Spirulina MCQs With Answer

Introduction: Spirulina (Arthrospira) is a nutrient-dense cyanobacterium extensively studied for its medicinal uses and health benefits. Rich in high-quality protein, phycocyanin, essential fatty acids (including GLA), vitamins, minerals and antioxidants, Spirulina shows anti-inflammatory, immunomodulatory, lipid-lowering and glucose-regulating effects. B. Pharm students should understand its bioactive constituents, mechanisms of action, clinical evidence, safety concerns (microcystin contamination, heavy metals), dosage ranges, quality control and regulatory status. Knowledge of pharmacognosy, analytical methods and potential drug–nutrient interactions is essential for safe therapeutic recommendations and product evaluation. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which pigment is primarily responsible for Spirulina’s characteristic blue color and many of its antioxidant and anti-inflammatory activities?

• Phycocyanin
• Chlorophyll a
• Beta-carotene
• Astaxanthin

Correct Answer: Phycocyanin

Q2. What approximate percentage of Spirulina’s dry weight is typically high-quality protein used in nutraceutical formulations?

• 5–10%
• 20–30%
• 60–70%
• 90–95%

Correct Answer: 60–70%

Q3. Which mechanism best explains Spirulina’s antioxidant action in biological systems?

• Chelation of dietary iron preventing absorption
• Direct free-radical scavenging via phycocyanin and carotenoids
• Inhibition of cytochrome P450 enzymes
• Blocking vitamin C metabolism

Correct Answer: Direct free-radical scavenging via phycocyanin and carotenoids

Q4. Clinical studies most consistently report which effect of Spirulina supplementation on lipid profiles?

• Increase in LDL cholesterol and triglycerides
• No change in lipid parameters
• Reduction in LDL cholesterol and triglycerides
• Induction of hypercholesterolemia

Correct Answer: Reduction in LDL cholesterol and triglycerides

Q5. Which of the following best summarizes Spirulina’s reported effects in glucose metabolism from clinical and preclinical studies?

• Marked hypoglycemia in all subjects
• May lower fasting blood glucose and improve insulin sensitivity
• Causes permanent pancreatic beta-cell destruction
• No interaction with glucose metabolism

Correct Answer: May lower fasting blood glucose and improve insulin sensitivity

Q6. Spirulina has been reported to modulate the immune system. Which immunological effect is commonly observed?

• Suppression of natural killer (NK) cell activity
• Enhancement of NK cell activity and increased cytokine production
• Selective depletion of CD4+ T cells
• Complete immunosuppression

Correct Answer: Enhancement of NK cell activity and increased cytokine production

Q7. What is the primary contamination risk of poorly produced Spirulina supplements that can cause hepatotoxicity?

• Microbial E. coli contamination
• Microcystin toxins from cyanobacterial contamination
• Aflatoxin B1 from mold contamination
• Excessive vitamin C addition

Correct Answer: Microcystin toxins from cyanobacterial contamination

Q8. In which patient population should Spirulina be used with caution due to its immune-stimulating properties?

• Patients with autoimmune disorders
• Patients with controlled hypertension
• Patients using topical antibiotics only
• Healthy adolescents with no comorbidities

Correct Answer: Patients with autoimmune disorders

Q9. What daily dose range of Spirulina has been commonly used in human clinical trials?

• 0.01–0.1 g/day
• 0.1–0.5 g/day
• 1–8 g/day
• 50–100 g/day

Correct Answer: 1–8 g/day

Q10. Which dosage forms are commonly used for Spirulina in pharmaceutical and nutraceutical products?

• Injectable solutions only
• Tablets, capsules, powders and standardized extracts
• Transdermal patches exclusively
• Inhalation aerosols only

Correct Answer: Tablets, capsules, powders and standardized extracts

Q11. Taxonomically, Spirulina belongs to which group?

• Green algae (Chlorophyta)
• Cyanobacteria (blue‑green algae)
• Fungi
• Dinoflagellates

Correct Answer: Cyanobacteria (blue‑green algae)

Q12. Which Spirulina component is widely used as a natural blue food colorant approved in some regions?

• Chlorophyll
• Phycocyanin
• Lutein
• Beta-sitosterol

Correct Answer: Phycocyanin

Q13. Which storage condition is most likely to degrade phycocyanin and reduce product potency?

• Cool, dark, dry storage
• Exposure to heat and light
• Low humidity refrigerated storage
• Storage under inert gas at low temperature

Correct Answer: Exposure to heat and light

Q14. Which simple analytical method is commonly used to quantify phycocyanin in Spirulina extracts?

• Gas chromatography–mass spectrometry (GC–MS)
• Spectrophotometric absorbance at ~620 nm
• Flame photometry for sodium content
• Polarimetry for optical rotation

Correct Answer: Spectrophotometric absorbance at ~620 nm

Q15. What effect has Spirulina supplementation shown on blood pressure in some clinical studies?

• Marked increase in diastolic pressure only
• May reduce systolic blood pressure modestly
• Universal normalization to 120/80 mmHg
• No studies have evaluated blood pressure

Correct Answer: May reduce systolic blood pressure modestly

Q16. Which unusual fatty acid is present in Spirulina and contributes to its nutritional profile?

• Omega-9 oleic acid only
• Gamma-linolenic acid (GLA)
• Trans-palmitoleic acid exclusively
• Stearidonic acid exclusively

Correct Answer: Gamma-linolenic acid (GLA)

Q17. Which solvent system is most appropriate for extracting water-soluble phycocyanin from Spirulina biomass?

• Nonpolar solvents like hexane
• Aqueous buffer (water-based extraction)
• Strongly acidic concentrated sulfuric acid
• Pure ethanol without water

Correct Answer: Aqueous buffer (water-based extraction)

Q18. What is the regulatory status of food-grade Spirulina (Arthrospira) in the United States?

• Classified as a Schedule I controlled substance
• Generally Recognized As Safe (GRAS) for specified uses
• Banned for all human consumption
• Approved only as a prescription drug

Correct Answer: Generally Recognized As Safe (GRAS) for specified uses

Q19. Spirulina supplementation has been associated with improvements in which hematological parameter in some studies?

• Decrease in hemoglobin concentration
• Increase in hemoglobin and hematocrit in anemic subjects
• Complete suppression of erythropoiesis
• Permanent aplastic anemia

Correct Answer: Increase in hemoglobin and hematocrit in anemic subjects

Q20. Which in vitro assay is commonly used to assess the antioxidant capacity of Spirulina extracts?

• Minimum inhibitory concentration (MIC) assay
• DPPH free radical scavenging assay
• Enzyme-linked immunosorbent assay (ELISA) for insulin
• Bradford protein assay

Correct Answer: DPPH free radical scavenging assay

Q21. Which contaminant is most important to screen for in Spirulina products due to similarity with other cyanobacteria?

• Shelf-stable preservatives
• Microcystin hepatotoxins
• Excessive vitamin B12
• Natural sugars

Correct Answer: Microcystin hepatotoxins

Q22. For which clinical indication is evidence most consistent supporting Spirulina supplementation?

• Acute bacterial infections
• Hyperlipidemia and dyslipidemia adjunct therapy
• Curative therapy for metastatic cancer
• Immediate treatment of stroke

Correct Answer: Hyperlipidemia and dyslipidemia adjunct therapy

Q23. Phycocyanin belongs to which class of biological molecules?

• Phycobiliproteins (pigment–protein complexes)
• Simple polysaccharides
• Saturated triglycerides
• Alkaloids

Correct Answer: Phycobiliproteins (pigment–protein complexes)

Q24. Compared with Chlorella, Spirulina is generally considered more digestible because:

• It contains chitin in the cell wall
• It lacks a rigid cellulose cell wall and is more easily digested
• It has an outer shell made of waxes
• It must be chemically lysed to be digestible

Correct Answer: It lacks a rigid cellulose cell wall and is more easily digested

Q25. Which factors most strongly influence the shelf life and potency of Spirulina powder?

• Color of packaging only
• Moisture, heat and light exposure
• Ambient CO2 concentration
• Altitude of storage

Correct Answer: Moisture, heat and light exposure

Q26. Which modern method is most reliable for authenticating Spirulina species and detecting adulteration?

• Organoleptic smell test
• DNA barcoding and PCR-based species identification
• Measuring only total protein content
• Checking tablet hardness in a tablet tester

Correct Answer: DNA barcoding and PCR-based species identification

Q27. Regarding pharmacokinetics of Spirulina proteins like phycocyanin, which statement is most accurate?

• Phycocyanin is fully absorbed intact into systemic circulation
• Proteins are largely digested to amino acids/peptides with limited intact absorption
• All Spirulina components are excreted unchanged in urine
• Phycocyanin acts only after being converted into glucose

Correct Answer: Proteins are largely digested to amino acids/peptides with limited intact absorption

Q28. Which adverse reaction has been reported, albeit rarely, with Spirulina ingestion?

• Anaphylactic allergic reactions
• Guaranteed development of renal failure
• Immediate severe hypoglycemia in all users
• Universal loss of hair within 24 hours

Correct Answer: Anaphylactic allergic reactions

Q29. In nonalcoholic fatty liver disease (NAFLD) and related studies, Spirulina supplementation has shown potential benefit by:

• Increasing ALT and AST permanently
• Reducing liver enzymes such as ALT and improving lipid parameters
• Causing acute fulminant hepatic failure in most patients
• Eliminating the need for diet and exercise

Correct Answer: Reducing liver enzymes such as ALT and improving lipid parameters

Q30. Which statement about vitamin B12 in Spirulina is correct and clinically relevant for B. Pharm students?

• Spirulina provides bioavailable active vitamin B12 sufficient for vegans
• Spirulina contains B12 analogues that are largely inactive in humans
• Spirulina is the richest source of heme iron but contains no B12 analogues
• Spirulina supplementation cures pernicious anemia without B12 injections

Correct Answer: Spirulina contains B12 analogues that are largely inactive in humans

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