Chai Hu (Bupleurum chinense) (Bupleurum chinense)

Chai Hu (Bupleurum chinense) is not consumed as a food for macronutrient value but is valued for its bioactive phytochemical composition. Key compounds include: **Saikosaponins** (primary active constituents, total concentration approximately 1.5–4.5% of dried root weight) — notably Saikosaponin A (anti-inflammatory, immunomodulatory; ~0.3–1.0%), Saikosaponin C (~0.2–0.6%), and Saikosaponin D (hepatoprotective, anti-inflammatory; ~0.3–1.2%). **Volatile oils** (~0.1–0.5% of dried root) containing α-pinene, limonene, linalool, and bupleurumol contribute to its aromatic and mild analgesic properties. **Flavonoids** including rutin, quercetin, and isorhamnetin (estimated total ~0.2–0.8%) provide antioxidant activity; quercetin has moderate oral bioavailability (~16–20%) enhanced by co-occurring glycosides. **Polysaccharides** (approximately 3–8% of dried root) contribute to immunostimulatory effects by activating macrophages. **Phytosterols** such as β-sitosterol and stigmasterol are present in trace amounts (~0.05–0.15%), supporting anti-inflammatory action. **Minerals** (per 100 g dried root, approximate): potassium ~800–1200 mg, calcium ~200–450 mg, magnesium ~150–300 mg, iron ~8–15 mg, zinc ~2–5 mg, manganese ~3–7 mg. **Vitamins**: trace amounts of vitamin C (~2–5 mg/100 g dried root) and small quantities of B-vitamins (B1, B2). **Crude fiber** content is approximately 15–25% of dried root. **Protein** content is roughly 5–9% of dried root weight, though it is not used as a protein source. **Lignans and organic acids** (ferulic acid, caffeic acid) are present in minor concentrations (~0.05–0.3%), contributing to hepatoprotective and antioxidant effects. **Bioavailability notes**: Saikosaponins are triterpenoid saponins with relatively low oral bioavailability (~5–15%) due to extensive first-pass metabolism and hydrolysis by gut microbiota (e.g., Saikosaponin A is converted to prosaikogenin); decoction (traditional preparation) improves extraction efficiency. Co-administration with other herbs in classical formulas (e.g., Xiao Chai Hu Tang) may enhance absorption via synergistic interactions. Saikosaponin D shows improved bioavailability when formulated with lipid-based carriers.