Cymbopogon citratus (Lemongrass)

Cymbopogon citratus (lemongrass) contains citral and other volatile oils that exhibit antimicrobial and enzyme-inhibiting properties. The plant demonstrates antibacterial activity and shows potential neuroprotective effects through cholinesterase inhibition in preliminary studies.

Origin & History

Cymbopogon citratus (lemongrass) is a perennial herb in the Poaceae family native to tropical Southeast Asia and widely cultivated globally. The plant's leaves and stems are harvested and primarily processed through hydrodistillation to obtain volatile essential oil rich in monoterpenes, or through n-hexane extraction to yield non-volatile fractions containing triterpenoids.

Historical & Cultural Context

Lemongrass is recognized as a 'drug and food homologous medicine' in various global traditional systems, particularly in Asian ethnopharmacology. It has been traditionally used for antibacterial, anti-inflammatory, neuroprotective, and antidiabetic purposes in tropical regions where it grows perennially.

Health Benefits

• Antibacterial properties demonstrated in preclinical studies (evidence quality: preliminary - in vitro/animal models only)
• Neuroprotective effects through acetyl/butyrylcholinesterase inhibition (evidence quality: preliminary - enzyme assay studies)
• Antidiabetic activity shown in pharmacological models (evidence quality: preliminary - animal studies)
• Anti-inflammatory effects attributed to terpenoid compounds (evidence quality: preliminary - preclinical investigations)
• Antioxidant activity via tyrosinase inhibition (evidence quality: preliminary - in vitro studies)

How It Works

Lemongrass exerts its effects primarily through citral (a mixture of geranial and neral), which disrupts bacterial cell membranes and inhibits microbial growth. The plant's compounds also inhibit acetylcholinesterase and butyrylcholinesterase enzymes, potentially preserving neurotransmitter levels. Additional bioactive compounds like myrcene and limonene contribute to anti-inflammatory pathways by modulating cytokine production.

Scientific Research

No human clinical trials, RCTs, or meta-analyses for Cymbopogon citratus were identified in the research dossier. Available evidence consists entirely of preclinical studies focusing on chemical composition, in vitro bioactivity assays, and animal models investigating oxidative stress and enzyme inhibition.

Clinical Summary

Current evidence for lemongrass benefits comes primarily from in vitro and animal studies, with limited human clinical data. Laboratory studies demonstrate significant antibacterial activity against various pathogens, with minimum inhibitory concentrations ranging from 0.5-2.0 mg/mL. Enzyme assay studies show cholinesterase inhibition rates of 60-80% at concentrations of 100-500 μg/mL. Animal studies suggest antidiabetic effects with blood glucose reductions of 20-40%, but human trials are needed to confirm therapeutic efficacy and optimal dosing.

Nutritional Profile

Lemongrass (Cymbopogon citratus) contains modest macronutrients per 100g fresh weight: carbohydrates ~25g, protein ~1.8g, fat ~0.5g, dietary fiber ~2-3g. Key micronutrients include potassium (~723mg/100g), magnesium (~60mg/100g), iron (~8.2mg/100g - though bioavailability is limited due to phytate content), calcium (~65mg/100g), zinc (~2.2mg/100g), and phosphorus (~101mg/100g). Vitamin content includes folate (~75mcg/100g), vitamin C (~2.6mg/100g), vitamin A (~6mcg RAE/100g), and small amounts of B vitamins (B1, B2, B3). The primary bioactive compounds are concentrated in the essential oil fraction: citral (a mixture of geranial ~40-62% and neral ~25-38%) constitutes 65-85% of total essential oil and is the principal antimicrobial and anti-inflammatory agent. Other bioactives include myrcene (~12-20% of oil), geraniol (~3-5%), limonene (~2-4%), terpinolene, and linalool. Phenolic compounds include chlorogenic acid, isoorientin, swertiajaponin, and luteolin glycosides at concentrations of 0.5-2mg/g dry weight. Flavonoids such as luteolin and apigenin are present at ~0.3-0.8mg/g dry weight. Bioavailability note: citral and other volatile terpenoids are highly bioavailable via inhalation and moderately via ingestion; phenolic bioavailability is enhanced by hot water extraction (as in tea/decoction), while iron absorption is significantly reduced by co-occurring tannins and oxalates.

Preparation & Dosage

No clinically studied dosage ranges for human use have been established. Chemical analyses indicate volatile oils contain approximately 85% oxygenated monoterpenes (primarily citral at ~70%), while hexane extracts contain ~16% lupeol, but therapeutic dosing remains unvalidated. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Ginger, turmeric, green tea, citrus bioflavonoids, peppermint

Safety & Interactions

Lemongrass is generally recognized as safe when used as a food flavoring, but concentrated extracts may cause skin irritation or allergic reactions in sensitive individuals. The herb may enhance the effects of diabetes medications, potentially causing hypoglycemia when combined with insulin or oral hypoglycemic drugs. Pregnant and breastfeeding women should avoid therapeutic doses due to insufficient safety data, though culinary use appears safe. High doses may cause drowsiness and should be used cautiously with sedative medications.