Which herb from Lamiaceae has leaves as parts used, containing thujone and rosmarinic acid, with antimicrobial and anti-inflammatory actions?

• A. Salvia officinalis
• B. Usnea barbata
• C. Rhamnus frangula
• D. Tribulus terrestris

Answer: (A)

Salvia officinalis, a member of the Lamiaceae, fits this description because sage is traditionally used with the leaves, and its essential oil and polyphenols include thujone and rosmarinic acid. Thujone is a volatile constituent in sage oil that contributes antimicrobial effects, while rosmarinic acid is a prominent anti-inflammatory and antioxidant compound in sage. Together, these constituents explain the herb’s antimicrobial and anti-inflammatory actions. The other plants listed do not share these features: they are not Lamiaceae or their main active components and used parts don’t align with thujone and rosmarinic acid in leaves.