Glycosides – Senna MCQs With Answer

Glycosides – Senna MCQs With Answer

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Glycosides – Senna MCQs With Answer

Glycosides from Senna (Cassia spp.) are clinically important anthraquinone glycosides used as stimulant laxatives in pharmacy practice. B.Pharm students should master sennosides A and B chemistry, sources (Senna leaf, pods), extraction, analytical assays (HPLC, Bornträger’s test), mechanism (bacterial hydrolysis to active anthrone, stimulation of colonic motility and secretion), therapeutic uses, dosing, adverse effects (abdominal cramps, hypokalaemia, melanosis coli), contraindications and quality control. Understanding pharmacokinetics, metabolism by gut flora, and drug interactions (digitalis potentiation) is essential for safe use and formulation. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which class of glycosides do the active constituents of Senna belong to?

  • Cardiac glycosides
  • Anthraquinone glycosides
  • Flavonoid glycosides
  • Steroidal glycosides

Correct Answer: Anthraquinone glycosides

Q2. What is the primary botanical source of pharmacopeial Senna?

  • Rheum palmatum
  • Cassia angustifolia (Senna)
  • Aloe vera
  • Digitalis purpurea

Correct Answer: Cassia angustifolia (Senna)

Q3. Which are the major active glycosides found in Senna?

  • Sennosides A and B
  • Digoxin and digitoxin
  • Quercetin and rutin
  • Glycyrrhizin and liquiritin

Correct Answer: Sennosides A and B

Q4. Chemically sennosides are best described as which of the following?

  • Monoglycosides
  • Dianthrone glycosides
  • Glycosphingolipids
  • Polyketide lactones

Correct Answer: Dianthrone glycosides

Q5. The primary mechanism of action of senna laxatives is:

  • Osmotic retention of water in the colon
  • Inhibition of acetylcholinesterase in the gut
  • Bacterial hydrolysis to active anthrone metabolites that stimulate colonic peristalsis and secretion
  • Formation of viscous bulk to increase stool volume

Correct Answer: Bacterial hydrolysis to active anthrone metabolites that stimulate colonic peristalsis and secretion

Q6. Typical oral onset of action for senna preparations is:

  • 15–30 minutes
  • 1–3 hours
  • 6–12 hours
  • 24–48 hours

Correct Answer: 6–12 hours

Q7. The most common adverse effect reported with senna use is:

  • Hepatotoxicity
  • Abdominal cramping and colic
  • Profound bradycardia
  • Severe hypertension

Correct Answer: Abdominal cramping and colic

Q8. Chronic abuse of stimulant laxatives like senna can lead to:

  • Melanosis coli and laxative dependency
  • Increased bone mineral density
  • Improved renal clearance
  • Permanent hypernatremia

Correct Answer: Melanosis coli and laxative dependency

Q9. Senna is contraindicated in which clinical scenario?

  • Functional constipation with no alarm features
  • Intestinal obstruction or acute abdominal pain of unknown origin
  • Occasional opioid-related constipation after evaluation
  • Mild hemorrhoids without systemic signs

Correct Answer: Intestinal obstruction or acute abdominal pain of unknown origin

Q10. Which drug interaction is clinically important with chronic senna-induced hypokalaemia?

  • Reduced anticoagulant effect of warfarin
  • Potentiation of digitalis toxicity
  • Increased effects of beta blockers
  • Decreased absorption of oral contraceptives

Correct Answer: Potentiation of digitalis toxicity

Q11. Which qualitative test is commonly used to detect anthraquinones after hydrolysis of Senna?

  • Benedict’s test
  • Biuret test
  • Borax test
  • Bornträger’s test

Correct Answer: Bornträger’s test

Q12. Which analytical technique is preferred for quantitative assay of sennosides in formulations?

  • Gas chromatography
  • High-performance liquid chromatography (HPLC)
  • Nephelometry
  • Polarimetry

Correct Answer: High-performance liquid chromatography (HPLC)

Q13. The aglycone moiety of sennosides belongs to which chemical family?

  • Flavone derivatives
  • Terpenoid lactones
  • Anthraquinone derivatives
  • Alkaloid derivatives

Correct Answer: Anthraquinone derivatives

Q14. Which part of the Senna plant is mainly used for medicinal preparations?

  • Roots
  • Leaves and leaflets (folia)
  • Seeds
  • Flowers

Correct Answer: Leaves and leaflets (folia)

Q15. The standard therapeutic daily dose of sennosides for adults is approximately:

  • 5 mg once daily
  • 15–30 mg per day
  • 100–200 mg per day
  • 500–1000 mg per day

Correct Answer: 15–30 mg per day

Q16. Senna glycosides are chemically unstable under which condition?

  • In inert, dry, dark storage
  • Prolonged heating and acidic hydrolysis
  • In the presence of silica gel
  • At low humidity and low temperature

Correct Answer: Prolonged heating and acidic hydrolysis

Q17. Senna is classified therapeutically as a:

  • Bulk-forming laxative
  • Osmotic laxative
  • Stimulant (irritant) laxative
  • Surfactant laxative

Correct Answer: Stimulant (irritant) laxative

Q18. The primary site of activation (conversion to active anthrone) of sennosides is:

  • Stomach by gastric acid
  • Small intestine by pancreatic enzymes
  • Colon by bacterial enzymes
  • Liver by hepatic microsomes

Correct Answer: Colon by bacterial enzymes

Q19. Stimulation by senna mainly targets which component to increase motility and secretion?

  • Gastric parietal cells
  • Enteric nerves and colonic mucosal cells
  • Pancreatic acinar cells
  • Hepatocytes

Correct Answer: Enteric nerves and colonic mucosal cells

Q20. Which common dosage form is Senna available as in pharmacy practice?

  • Injectable solution
  • Tablets and oral syrups
  • Topical cream
  • Inhalation aerosol

Correct Answer: Tablets and oral syrups

Q21. A common assay approach for sennosides in crude drug involves:

  • Direct titration of intact glycosides
  • Hydrolysis to anthraquinones followed by colorimetric determination
  • X-ray diffraction
  • Karl Fischer titration

Correct Answer: Hydrolysis to anthraquinones followed by colorimetric determination

Q22. Prolonged or excessive senna use can lead to which electrolyte disturbance?

  • Hypercalcaemia
  • Hypokalemia
  • Hypermagnesemia
  • Hyponatremia only

Correct Answer: Hypokalemia

Q23. The reversible brown-black pigmentation of the colon associated with chronic senna use is called:

  • Steatosis
  • Melanosis coli
  • Colonic polyposis
  • Hemochromatosis

Correct Answer: Melanosis coli

Q24. What is the recommended stance on senna use during pregnancy?

  • First-line laxative throughout pregnancy
  • Use with caution; not recommended as first-line in pregnancy
  • Strictly contraindicated in all trimesters
  • Safe in unlimited doses

Correct Answer: Use with caution; not recommended as first-line in pregnancy

Q25. The enzymatic activity responsible for converting sennosides to active metabolites is primarily:

  • Alpha-amylase
  • Beta-glucosidase from gut bacteria
  • Cytochrome P450 monooxygenase
  • Acetylcholinesterase

Correct Answer: Beta-glucosidase from gut bacteria

Q26. Which stereoisomers of sennosides are mainly responsible for laxative activity?

  • Sennosides C and D
  • Sennosides A and B
  • Only sennoside E
  • Only the aglycone without sugars

Correct Answer: Sennosides A and B

Q27. Which solvent is commonly used for extraction of sennosides from Senna leaves in laboratories?

  • Hexane
  • Methanol or aqueous methanol
  • Diethyl ether
  • Carbon tetrachloride

Correct Answer: Methanol or aqueous methanol

Q28. Continuous daily use of stimulant laxatives such as senna is generally not recommended for more than:

  • 1–2 days
  • 1–2 weeks
  • 6 months
  • Indefinitely if tolerated

Correct Answer: 1–2 weeks

Q29. The pigment that accumulates in macrophages in melanosis coli is primarily:

  • Melanin
  • Lipofuscin
  • Biliverdin
  • Hemosiderin

Correct Answer: Lipofuscin

Q30. Which test procedure can distinguish between free anthraquinones and bound (glycosidic) anthraquinones in a sample?

  • Bornträger’s test without prior hydrolysis detects bound glycosides
  • Bornträger’s test after hydrolysis distinguishes bound anthraquinones
  • Kjeldahl nitrogen estimation
  • Flame photometry

Correct Answer: Bornträger’s test after hydrolysis distinguishes bound anthraquinones

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