Xi Jiao Di Huang Tang (Rhinoceros Horn and Rehmannia)

Xi Jiao Di Huang Tang is a classical TCM decoction comprising four primary herbs, each contributing distinct bioactive compounds rather than conventional macronutrients. **Shui Niu Jiao (Water Buffalo Horn, substitute for Rhinoceros Horn):** Contains keratin, peptides, amino acids (including cysteine, arginine, tyrosine), calcium phosphate (~15-20% by weight), cholesterol, and trace minerals (zinc, iron). Bioactive peptides may exert antipyretic and anti-inflammatory effects; bioavailability of mineral content is moderate due to prolonged decoction required (typically 3+ hours). **Sheng Di Huang (Rehmannia glutinosa, raw, ~30g typical dose):** Rich in iridoid glycosides (catalpol ~2-5% dry weight, aucubin, rehmannioside A-D), polysaccharides (stachyose ~40-50% of sugars), amino acids, mannitol, stigmasterol, campesterol, and trace minerals (iron, zinc, manganese). Catalpol demonstrates neuroprotective and anti-inflammatory properties; oral bioavailability of catalpol is approximately 20-30%. **Shao Yao (Paeonia lactiflora, ~12g typical dose):** Contains paeoniflorin (~3-6% dry weight), albiflorin, benzoylpaeoniflorin, paeonol, tannins (gallotannins ~1-2%), beta-sitosterol, and benzoic acid. Paeoniflorin has documented anti-inflammatory, immunomodulatory, and hepatoprotective activity; oral bioavailability of paeoniflorin is low (~3-5%) but enhanced by decoction and co-administration with glycyrrhizin-containing formulas. **Mu Dan Pi (Paeonia suffruticosa cortex, ~9g typical dose):** Contains paeonol (~3-5% dry weight), paeonoside, paeoniflorin, benzoyloxy-paeoniflorin, tannins, phytosterols, and volatile oils. Paeonol demonstrates anticoagulant, anti-inflammatory, and antimicrobial activity; bioavailability of paeonol is moderate (~40-50%) and improved by decoction. **Overall formula profile:** Essentially negligible macronutrient content (protein <2g, fat <1g, carbohydrates ~5-10g per prepared dose, primarily from Rehmannia polysaccharides). No significant vitamin content. Trace minerals include calcium (~50-100mg), iron (~2-5mg), zinc (~1-2mg), and manganese (~0.5-1mg) per standard decoction dose, though bioavailability varies. The formula's therapeutic value is derived from synergistic bioactive compounds rather than nutritional content. Combined iridoid glycosides, monoterpene glycosides (paeoniflorin), and phenolic compounds (paeonol) work synergistically to clear blood-level heat, cool blood, and resolve stasis in TCM paradigm.