Vasaka (Adhatoda vasica)

Vasaka (Adhatoda vasica) is not consumed as a food source, so a traditional macronutrient profile (carbohydrates, fats, protein) is not typically characterized. Its significance lies in its bioactive phytochemical composition. Key compounds include: Quinazoline alkaloids — vasicine (peganine, approximately 0.5–1.5% dry weight of leaves) and vasicinone (an oxidation product of vasicine, approximately 0.2–0.5%), which are the primary bronchodilatory and expectorant agents; Essential oils — including small amounts of monoterpenes and sesquiterpenes contributing to antimicrobial activity; Flavonoids — including apigenin, kaempferol, and quercetin glycosides (collectively estimated at 0.3–0.8% dry weight), contributing antioxidant and anti-inflammatory effects; Tannins — approximately 2–5% dry weight, providing astringent and antimicrobial properties; Saponins — present in moderate amounts, contributing to expectorant action by reducing surface tension of mucus; Vitamin C (ascorbic acid) — detected in leaves at approximately 50–130 mg per 100 g fresh weight, contributing to antioxidant defense; Minerals — leaves contain potassium (~1.2–1.8% dry weight), calcium (~0.8–1.4% dry weight), magnesium (~0.3–0.6% dry weight), iron (~15–25 mg per 100 g dry weight), and zinc (~3–5 mg per 100 g dry weight); Crude fiber — approximately 12–18% of dry leaf weight; Beta-sitosterol and other phytosterols — present in minor quantities (~0.05–0.1%), with potential anti-inflammatory roles; Gallic acid and other phenolic acids — contributing to total phenolic content estimated at 3–6 mg GAE/g dry weight. Bioavailability notes: Vasicine is well-absorbed orally and has demonstrated good bioavailability in pharmacokinetic studies, with peak plasma levels reached within 1–2 hours. Vasicinone, formed both in vivo by oxidation and present natively, also shows reasonable oral bioavailability. Flavonoid glycosides have moderate bioavailability, enhanced when consumed with lipids or in decoction form. Tannins may reduce the bioavailability of co-consumed minerals (iron, zinc) through chelation. Traditional preparations as aqueous decoctions (kashaya) or expressed leaf juice (svarasa) optimize extraction of water-soluble alkaloids and phenolics.