Named Bioactive Compounds · Compound
Carnosol
Moderate Evidencecompound
Hermetica Superfood Encyclopedia
Carnosol is a phenolic diterpenoid compound found primarily in rosemary that exhibits potent antioxidant and anti-inflammatory properties. It functions by scavenging reactive oxygen species and suppressing the NF-κB inflammatory pathway.
Carnosol is a phenolic diterpenoid compound (C20H26O4) found primarily in herbs of the Lamiaceae family, particularly rosemary (Rosmarinus officinalis) and sage (Salvia officinalis), where it occurs in leaves, chloroplasts, and glandular trichomes at concentrations up to 0.2% of dry leaf weight. It forms naturally as an oxidized derivative of carnosic acid and is typically extracted from dried leaves using ethanolic or methanolic solvents.
No human clinical trials, randomized controlled trials, or meta-analyses have been conducted on isolated carnosol. Current evidence is limited to in vitro cell line studies and animal research, with human data available only indirectly through rosemary extract studies containing multiple compounds.
No clinically studied dosages exist for isolated carnosol due to absence of human trials. In vitro studies used concentrations of 28-157 μM (9-52 μg/mL). Rosemary extracts standardized to 5-10% total diterpenes (carnosol plus carnosic acid) are typically dosed at 100-500 mg/day in general antioxidant studies. Consult a healthcare provider before starting any new supplement.
Carnosol (C20H26O4, MW 330.42 g/mol) is a phenolic diterpene lactone, not a nutritional macronutrient source. It is a bioactive secondary metabolite found primarily in rosemary (Rosmarinus officinalis) and sage (Salvia officinalis). Key details: • Concentration in rosemary leaf: approximately 0.02–0.4% dry weight (~0.2–4 mg/g dried herb), varying by cultivar, harvest time, and extraction method. • Concentration in sage leaf: approximately 0.01–0.2% dry weight. • Biosynthetically derived from carnosic acid via oxidative lactonization; carnosic acid (its precursor) is typically present at higher concentrations (~1.5–2.5% dry weight in rosemary) and readily converts to carnosol during drying, heating, or extraction. • Lipophilic compound (LogP ~3.6), soluble in ethanol, DMSO, and lipid matrices; poorly soluble in water (<0.1 mg/mL). • Bioavailability notes: Oral bioavailability is considered low due to poor aqueous solubility and significant first-pass hepatic metabolism; absorption is enhanced when consumed with dietary fats or lipid-based delivery systems. In vitro studies suggest phase I (CYP450-mediated hydroxylation) and phase II (glucuronidation, sulfation) metabolism. Plasma concentrations in animal models after oral dosing (~30–90 mg/kg) reach low micromolar levels (~1–5 μM), suggesting limited but measurable systemic availability. • No macronutrient value (no significant protein, carbohydrate, fat, or fiber contribution at typical dietary exposure levels). • No vitamin or mineral content inherent to the compound itself. • Co-occurring bioactive compounds in rosemary extract (typical context of dietary exposure): carnosic acid (~15–25 mg/g extract), rosmarinic acid (~10–50 mg/g extract), ursolic acid (~2–10 mg/g extract), and smaller amounts of rosmanol, epirosmanol, and methyl carnosate. • Typical dietary intake from culinary rosemary use: estimated at <5 mg/day carnosol from ~1–2 g dried rosemary; concentrated rosemary extracts (standardized supplements) may deliver 10–50 mg carnosol per dose. • EFSA-approved rosemary extracts (E392) used as food antioxidant additives contain carnosol + carnosic acid combined at standardized levels (typically ≥10% w/w combined diterpenes).
Carnosol exerts its effects primarily through suppression of the nuclear factor-κB (NF-κB) signaling pathway, reducing inflammatory cytokine production. It scavenges reactive oxygen species including hydroxyl radicals and superoxide anions, protecting cellular lipids from peroxidation. The compound also modulates various enzymes involved in oxidative stress responses and inflammatory cascades.
Current evidence for carnosol consists primarily of in vitro laboratory studies and animal research, with limited human clinical data available. Laboratory studies have demonstrated significant antioxidant activity and NF-κB pathway suppression at concentrations ranging from 10-50 μM. Animal studies suggest potential anti-cancer effects, but sample sizes are typically small (n=8-20 per group). Human clinical trials are needed to establish therapeutic efficacy and optimal dosing protocols.
Carnosol appears generally well-tolerated when consumed through dietary sources like rosemary, with no significant adverse effects reported in animal studies. However, concentrated supplement forms lack comprehensive safety data, particularly regarding long-term use and potential drug interactions. The compound may theoretically interact with medications metabolized by cytochrome P450 enzymes, though specific interactions have not been documented. Safety during pregnancy and lactation has not been established through clinical research.
