Herbs (Global Traditional) · European
Calendula (Calendula officinalis) (Calendula officinalis)
Moderate Evidencebotanical
Hermetica Superfood Encyclopedia
Calendula officinalis contains bioactive compounds like isorhamnetin and calenduloside E that provide antioxidant and anti-inflammatory effects. The flower extracts scavenge free radicals through multiple pathways while modulating inflammatory mediators.
Calendula officinalis, commonly known as pot marigold, is a flowering plant native to the Mediterranean region that has been used in traditional medicine for centuries. The plant's therapeutic applications derive from essential oils extracted from its flowers and leaves, as well as hydroalcoholic extracts that concentrate bioactive compounds including terpenoids, flavonoids, coumarines, quinones, and carotenoids.
The available evidence consists primarily of in vitro (laboratory) and in vivo (animal model) studies demonstrating antidiabetic, anti-inflammatory, anti-tumor, anticancer, and gastroprotective activity. No human clinical trials, randomized controlled trials (RCTs), or meta-analyses with PubMed PMIDs were provided in the research dossier.
The research does not provide clinically studied dosage ranges for human use or standardization specifications for different formulations. Studies used varying extraction methods (50:50 hydroalcoholic extracts, 100% ethanol extracts, essential oils) but reported results in laboratory units rather than human dosing recommendations. Consult a healthcare provider before starting any new supplement.
Calendula officinalis flowers are not consumed as a significant macronutrient source but are valued for their dense bioactive phytochemical profile. **Carotenoids:** Rich in carotenoids including β-carotene (up to 8.4 mg/100 g dry weight), lutein, lycopene, and zeaxanthin; the orange/yellow pigmentation is largely attributable to flavoxanthin, auroxanthin, and rubixanthin (total carotenoid content approximately 14–34 mg/100 g dry petals depending on cultivar and extraction method). **Flavonoids:** Major flavonoids include isorhamnetin-3-O-glucoside, quercetin-3-O-glucoside, rutin (quercetin-3-O-rutinoside), and narcissin (isorhamnetin-3-O-rutinoside); total flavonoid content ranges from approximately 0.3–0.8% of dry flower weight. **Triterpenoids:** Pentacyclic triterpene alcohols and their esters are signature compounds — faradiol, arnidiol, calenduladiol, and ψ-taraxasterol, with faradiol esters comprising approximately 2–4% of dry flower weight; faradiol is considered the primary anti-inflammatory triterpenoid. **Essential oil:** Yield approximately 0.1–0.4% from dried flowers, containing α-cadinol, α-cadinene, γ-cadinene, limonene, 1,8-cineole, and α-muurolol. **Polysaccharides:** Water-soluble polysaccharides (~15% of dry weight) including galactans, arabinogalactans, and rhamnogalacturonans with reported immunostimulatory properties. **Saponins:** Oleanane-type saponins (calendulosides A–F) present at approximately 2–10% dry weight. **Phenolic acids:** Chlorogenic acid, caffeic acid, and coumaric acid derivatives; total phenolic content approximately 20–45 mg gallic acid equivalents (GAE)/g dry extract. **Minerals (per 100 g dry flower):** Potassium (~1,200–1,500 mg), calcium (~800–1,100 mg), magnesium (~200–350 mg), iron (~15–25 mg), zinc (~3–5 mg), and manganese (~2–4 mg). **Vitamins:** Modest amounts of vitamin C (~10–15 mg/100 g fresh petals); provitamin A activity from β-carotene. **Fiber:** Crude fiber approximately 10–15% of dry flower weight. **Protein:** Approximately 7–12% of dry weight (not a practical dietary protein source). **Fatty acids (seed oil, distinct from flower):** Calendic acid (a conjugated linolenic acid isomer, 18:3) constitutes ~55–62% of seed oil fatty acids; linoleic acid ~28–32%; oleic acid ~4–6%. **Bioavailability notes:** Carotenoid absorption is enhanced with co-ingestion of dietary fat; faradiol and triterpenoid esters show improved absorption in lipophilic carriers (oils, ointment bases). Flavonoid glycosides undergo hydrolysis by intestinal β-glucosidases before absorption, with oral bioavailability of quercetin glycosides estimated at 3–7%. Polysaccharide bioactivity is primarily via gut-associated lymphoid tissue (GALT) interaction rather than systemic absorption. Topical application of triterpenoid-rich preparations shows high local bioavailability in skin layers but limited systemic uptake.
Calendula's flavonoids like isorhamnetin and quercetin inhibit pro-inflammatory enzymes including cyclooxygenase and lipoxygenase pathways. The triterpene saponins, particularly calenduloside E, modulate nuclear factor-kappa B (NF-κB) signaling to reduce inflammatory cytokine production. Antioxidant activity occurs through direct free radical scavenging and upregulation of endogenous antioxidant enzymes like superoxide dismutase.
Most evidence for calendula comes from in vitro and animal studies, with limited human clinical trials. Topical calendula preparations showed wound healing benefits in small studies of 20-40 participants. The flower extracts demonstrated DPPH radical scavenging at IC50 values of 100 µg/mL and stronger ABTS radical inhibition at 6.5 µg/mL in laboratory studies. More robust human clinical trials are needed to establish therapeutic dosages and efficacy for internal use.
Calendula is generally well-tolerated when used topically or as tea, but may cause allergic reactions in individuals sensitive to Asteraceae family plants. No significant drug interactions have been reported, though theoretical concerns exist with anticoagulant medications due to potential bleeding risk enhancement. Pregnancy and breastfeeding safety data is limited, so use should be avoided during these periods. High doses may cause gastrointestinal upset including nausea and stomach irritation.
