Introduction: Ginkgo (Ginkgo biloba) is a widely studied herbal drug with important medicinal uses and health benefits relevant to B. Pharm students. The standardized leaf extract (EGb 761) contains flavonoid glycosides and terpene lactones (ginkgolides, bilobalide) offering antioxidant, anti-inflammatory, neuroprotective and platelet-activating factor (PAF) antagonistic effects. Clinical applications include cognitive impairment, dementia, and intermittent claudication, while safety concerns involve bleeding risk, interactions (e.g., warfarin), and seed ginkgotoxin toxicity. Quality control, standardization (24% flavone glycosides, 6% terpene lactones) and formulation considerations are critical for therapeutic efficacy. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which are the primary active constituents in Ginkgo biloba leaf extract responsible for its pharmacological activity?
- Alkaloids and glycosides
- Flavonoid glycosides and terpene lactones (ginkgolides and bilobalide)
- Saponins and tannins
- Essential oils and coumarins
Correct Answer: Flavonoid glycosides and terpene lactones (ginkgolides and bilobalide)
Q2. The commonly used standardized extract EGb 761 is standardized to which composition?
- 10% flavone glycosides and 2% terpene lactones
- 24% flavone glycosides and 6% terpene lactones
- 40% flavonoids and 10% polyphenols
- 5% ginkgolic acids and 20% terpenes
Correct Answer: 24% flavone glycosides and 6% terpene lactones
Q3. What is a major mechanism by which Ginkgo extract exerts an anti-platelet effect?
- Inhibition of cyclooxygenase-1 (COX-1)
- Antagonism of platelet-activating factor (PAF)
- Activation of thromboxane A2 synthesis
- Enhancement of fibrinogen binding to platelets
Correct Answer: Antagonism of platelet-activating factor (PAF)
Q4. Which clinical indication has the strongest evidence base for Ginkgo biloba extract?
- Treatment of acute bacterial infections
- Improvement of cognitive function in mild-to-moderate dementia and vascular cognitive impairment
- Cure for Parkinson’s disease
- Primary treatment for major depressive disorder
Correct Answer: Improvement of cognitive function in mild-to-moderate dementia and vascular cognitive impairment
Q5. What is the typical daily dose range recommended for standardized Ginkgo leaf extract (EGb 761) in clinical studies?
- 10–20 mg/day
- 50–80 mg/day
- 120–240 mg/day
- 500–1000 mg/day
Correct Answer: 120–240 mg/day
Q6. Which toxic compound is associated with Ginkgo seeds and can cause seizures if consumed in large amounts?
- Ginkgolic acid
- 4′-O-methylpyridoxine (ginkgotoxin)
- Bilobalide
- Ginkgolide B
Correct Answer: 4′-O-methylpyridoxine (ginkgotoxin)
Q7. Which important drug interaction is a safety concern with Ginkgo biloba?
- Reduced blood glucose levels with metformin
- Increased bleeding risk with anticoagulants such as warfarin
- Marked increase in blood pressure with ACE inhibitors
- Severe sedation with benzodiazepines
Correct Answer: Increased bleeding risk with anticoagulants such as warfarin
Q8. Which analytical technique is commonly used for quality control and fingerprinting of Ginkgo leaf extracts in pharmacognosy labs?
- Thin layer chromatography without visualization
- High-performance thin-layer chromatography (HPTLC)
- Simple pH titration
- Flame photometry
Correct Answer: High-performance thin-layer chromatography (HPTLC)
Q9. Which of the following is a terpene trilactone characteristic of Ginkgo and considered pharmacologically important?
- Quercetin
- Ginkgolide B
- Rutin
- Resveratrol
Correct Answer: Ginkgolide B
Q10. Why are ginkgolic acids controlled in standardized Ginkgo extracts?
- They provide the main therapeutic effect
- They are allergenic, cytotoxic and should be minimized (<5 ppm)
- They enhance absorption of flavonoids
- They improve taste and color
Correct Answer: They are allergenic, cytotoxic and should be minimized (<5 ppm)
Q11. Which statement best describes the oral absorption of Ginkgo flavonoids?
- Flavonoid glycosides are absorbed intact without any metabolism
- Flavonoid glycosides are hydrolyzed by gut microbiota to aglycones, which are absorbed
- They are directly absorbed in the stomach without modification
- Flavonoids are absorbed only after intravenous administration
Correct Answer: Flavonoid glycosides are hydrolyzed by gut microbiota to aglycones, which are absorbed
Q12. Common adverse effects associated with Ginkgo biloba leaf extract include:
- Severe renal failure in all patients
- Gastrointestinal upset, headache, dizziness, allergic skin reactions and increased bleeding risk
- Complete hair loss within 24 hours
- Profound hyperglycemia
Correct Answer: Gastrointestinal upset, headache, dizziness, allergic skin reactions and increased bleeding risk
Q13. Which patient group should generally avoid Ginkgo biloba use without medical supervision?
- Patients on anticoagulants such as warfarin
- Individuals taking vitamin C supplements
- People with mild seasonal allergies only
- Patients using topical moisturizers
Correct Answer: Patients on anticoagulants such as warfarin
Q14. The neuroprotective antioxidant action of Ginkgo is primarily due to:
- Direct inhibition of insulin secretion
- Free radical scavenging, mitochondrial protection and reduction of oxidative stress
- Stimulation of excitotoxic glutamate release
- Permanent increase in neuronal excitability
Correct Answer: Free radical scavenging, mitochondrial protection and reduction of oxidative stress
Q15. Which extraction method is commonly used to prepare standardized Ginkgo leaf extracts for therapeutic products?
- Cold water maceration of fresh roots
- Hydroalcoholic (organic solvent-water) extraction of dried leaves with further fractionation
- Steam distillation of seeds
- Direct compression of powdered leaves into tablets without extraction
Correct Answer: Hydroalcoholic (organic solvent-water) extraction of dried leaves with further fractionation
Q16. For optimal stability, standardized Ginkgo extracts should be stored under which conditions?
- Strong light and high humidity
- High temperature (above 40°C) and open air
- Cool, dry, dark place in airtight containers to protect flavonoids and terpenoids
- Mixed with citrus juices at room temperature
Correct Answer: Cool, dry, dark place in airtight containers to protect flavonoids and terpenoids
Q17. Which bioassay is most appropriate to evaluate Ginkgo’s anti-PAF activity in the lab?
- Antibacterial disc diffusion test
- Platelet aggregation assay using PAF-induced aggregation
- Serum electrolyte measurement
- Glucose tolerance test
Correct Answer: Platelet aggregation assay using PAF-induced aggregation
Q18. Bilobalide is primarily associated with which pharmacological property?
- Hepatotoxicity at microdose levels
- Neuroprotection and mitochondrial stabilization
- Strong adrenergic stimulation
- Selective inhibition of HMG-CoA reductase
Correct Answer: Neuroprotection and mitochondrial stabilization
Q19. Regulatory monographs for Ginkgo specify limits for ginkgolic acids to reduce adverse effects. What is the typical limit?
- <50% of extract
- <5 ppm (parts per million)
- <10 mg/mL in finished product
- No limit is recommended
Correct Answer: <5 ppm (parts per million)
Q20. Which general statement about Ginkgo and cytochrome P450 interactions is most accurate?
- Ginkgo has no potential to affect any CYP enzymes
- Ginkgo may interact with drugs metabolized by cytochrome P450 enzymes, so caution is advised
- Ginkgo universally inhibits CYP2D6 causing fatal toxicity with all drugs
- Ginkgo irreversibly destroys all hepatic CYP enzymes
Correct Answer: Ginkgo may interact with drugs metabolized by cytochrome P450 enzymes, so caution is advised
Q21. How does Ginkgo biloba help patients with intermittent claudication?
- By acting as a strong opioid analgesic
- Improving peripheral blood flow via vasodilation and antiplatelet effects
- By lowering LDL cholesterol dramatically
- By increasing skeletal muscle mass directly
Correct Answer: Improving peripheral blood flow via vasodilation and antiplatelet effects
Q22. Which clinical cognitive assessment tool is commonly used in trials to measure Ginkgo’s effect on cognition?
- Electrocardiogram (ECG)
- Mini-Mental State Examination (MMSE)
- Complete blood count (CBC)
- Arterial blood gas (ABG) analysis
Correct Answer: Mini-Mental State Examination (MMSE)
Q23. Which part of the Ginkgo plant is the primary source of ginkgotoxin and is associated with acute toxicity when eaten raw?
- Leaves
- Seeds (nuts)
- Bark
- Flowers
Correct Answer: Seeds (nuts)
Q24. Patients taking warfarin should have which parameter monitored if Ginkgo biloba is started?
- Blood glucose
- International Normalized Ratio (INR)
- Serum creatinine only
- Serum cholesterol
Correct Answer: International Normalized Ratio (INR)
Q25. Which official monographs or bodies provide guidance on Ginkgo biloba leaf extract quality and use?
- World Health Organization (WHO) and European Medicines Agency/ESCOP monographs
- Local weather bureau guidelines
- Food packaging color standards
- International Automotive Code
Correct Answer: World Health Organization (WHO) and European Medicines Agency/ESCOP monographs
Q26. Contact dermatitis associated with some Ginkgo preparations is primarily attributed to which component?
- Flavone glycosides
- Ginkgolic acids
- Bilobalide exclusively
- Ginkgolide A in pelleted sugar
Correct Answer: Ginkgolic acids
Q27. For pharmaceutical formulation of Ginkgo extract tablets, what is an important consideration to preserve activity?
- Formulate with high water content in the tablet core
- Use moisture-protective coatings and antioxidants to prevent degradation
- Store tablets in direct sunlight to activate flavonoids
- Exclude standardization to maintain natural variability
Correct Answer: Use moisture-protective coatings and antioxidants to prevent degradation
Q28. Which laboratory finding is consistent with Ginkgo’s pharmacological action on platelets?
- Increased platelet aggregation in response to ADP
- Inhibition of PAF-induced platelet aggregation
- Marked thrombocytosis in CBC
- Irreversible platelet activation by collagen only
Correct Answer: Inhibition of PAF-induced platelet aggregation
Q29. What is the approximate elimination half-life of ginkgolide B from EGb 761 reported in pharmacokinetic studies?
- Approximately 30 minutes
- Approximately 4 hours
- Approximately 48 hours
- Approximately 7 days
Correct Answer: Approximately 4 hours
Q30. Is Ginkgo biloba recommended during pregnancy?
- Yes, high doses are recommended to prevent morning sickness
- No, it is not recommended due to limited safety data and potential bleeding risk
- Yes, it is essential for fetal brain development
- Only raw seeds are recommended during pregnancy
Correct Answer: No, it is not recommended due to limited safety data and potential bleeding risk
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.
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