Which antimicrobial peptide is secreted by salivary glands and acts in the oral cavity against fungi by disrupting intracellular function?

• A. Bacteriocins
• B. Histatins
• C. Defensins
• D. Interferons

Answer: (B)

Histatins are the antimicrobial peptides secreted by the salivary glands that target fungi in the mouth. Their standout feature is antifungal activity against Candida species, achieved by getting into fungal cells and disrupting intracellular processes. This intracellular disruption—affecting energy production and vital cellular functions—leads to inhibition of growth and cell death, which is why histatins are particularly effective in the oral cavity.

Other options don’t fit as well. Bacteriocins are peptides made by bacteria to inhibit other bacteria, not human salivary peptides. Defensins are antimicrobial peptides that can disrupt membranes and have broad activity, but the specific action described here—entering fungal cells and impairing internal functions—is characteristic of histatins. Interferons are immune signaling proteins, not salivary antimicrobial peptides.