Lemongrass (Cymbopogon citratus)

Nomenclature & Taxonomic Classification

• Botanical Binomial: Cymbopogon citratus (DC.) Stapf
• Family: Poaceae
• Common Name(s): Lemongrass, West Indian Lemongrass, Cymbopogon, Bhutrinah (Ayurveda)
• Parts Used: Fresh or dried leaf blades and lower fibrous pseudostems.

Botanical Description, Habitat & Sustainability

• Physical Description: * Growth Habit: A large, coarse, glaucous, tufted perennial grass growing in dense clumps up to 1.5 to 2 meters tall.
  • Morphology: Features elongated, linear leaf blades with rough, sharp margins and a stout, ringed, bulbous base (pseudostem). Emits a pungent, crisp lemon aroma when crushed. Rarely flowers under standard cultivation.
• Habitat & Cultivation: Native to maritime Southeast Asia and Southern Asia. Thrives in tropical and subtropical regions with high humidity, abundant rainfall, and rich, sandy, loam soils.
• Sustainability Status: Secure; heavily cultivated for culinary use and worldwide essential oil markets.

Energetics & Traditional Actions

• Western Tissue States: Corrects Torpor (stagnation/sluggishness) and Irritation (heat/fever).
• Traditional Vector:
  • Ayurveda: Rasa (Taste): Katu (Pungent), Tikta (Bitter) | Virya (Energy): Ushna (Warm) | Vipaka (Post-Digestive Effect): Katu (Pungent) | Dosha Modulation: Pacifies Kapha and Vata; elevates Pitta in excess.
  • Traditional Chinese Medicine: Temperature: Warm | Taste: Acrid, Bitter | Organ Meridians Entered: Lung, Stomach, Liver
• Historical Folk Use: Extensively used in Brazilian folk medicine as a calming nervine, sedative, and anti-spasmodic. In Caribbean and Asian folk medicine, it is a quintessential diaphoretic remedy used to “break” acute fevers and settle digestive flatulence.

Phytochemistry & Pharmacological Dynamics

• Primary Phytochemicals: Volatile oil (0.2–0.6%, rich in citral [a mixture of geranial and neral], myrcene, geraniol), phenolic compounds (luteolin, apigenin), and chlorogenic acid.
• Mechanism of Action: > The primary volatile monoterpene citral has been shown to induce vascular endothelium-independent smooth muscle relaxation, likely via the blockade of L-type calcium channels. Furthermore, it exhibits broad-spectrum antimicrobial and antifungal profiles by disrupting cell membrane integrity in pathogens such as Candida albicans and Helicobacter pylori. The flavonoids offer notable anti-inflammatory action by selectively suppressing inducible nitric oxide synthase (iNOS).

Clinical Applications & Indications

• Primary Indications: Acute febrile conditions (as a hot diaphoretic tea), flatulent dyspepsia, intestinal cramping, and topical superficial fungal infections (tinea pedis/ringworm via essential oil).
• Secondary Indications: Mild insomnia, stress-induced hypertension, and oral care (as an antimicrobial mouthwash to manage gingivitis).
• Modern Clinical Evidence: Clinical evaluations demonstrate that Lemongrass decoctions possess mild diuretic and significant anxiolytic actions without impairing motor coordination. Studies also show that topical application of the essential oil or highly concentrated extracts effectively resolves dermatomycoses.

Preparation, Dosing & Extraction Matrix

• Optimal Menstruum & Extraction Guidelines: Water infusions capture the hydrophilic polyphenols and a fraction of the diaphoretic oils perfectly. For concentrated antimicrobial tincture formulations, a high-proof alcohol (70–80% EtOH) is mandatory to fully dissolve the lipophilic myrcene and citral compounds.

Standard Dosage Parameters

Safety Profile, Contraindications & Drug Interactions

• Contraindications: Pure essential oil should never be applied undiluted to mucous membranes or sensitive skin due to severe risk of contact dermatitis. Avoid oral therapeutic essential oil ingestion during pregnancy.
• Side Effects & Toxicity Thresholds: Ingestion of whole-plant teas is incredibly safe. Inhalation of the essential oil may occasionally trigger mild bronchospasm in highly sensitive asthmatic individuals.
• Pharmaceutical Cross-Interactions: * Enzyme Alterations: Citral can inhibit CYP2B6 activity minorly at massive, continuous oral concentrations.
  • Additive Pathways: Antifungals: May act synergistically with topical azole medications (e.g., clotrimazole) to clear cutaneous yeast infections.

References

1. Negrelle, R. R., & Gomes, E. C. (2007). Cymbopogon citratus: An overview. Journal of Essential Oil Bearing Plants, 10(4), 258-271.
2. Carbajal, D., et al. (1989). Pharmacological study of Cymbopogon citratus leaves. Journal of Ethnopharmacology, 25(1), 103-115.
3. Lorenzi, H., & Matos, F. J. A. (2002). Plantas Medicinais no Brasil. Instituto Plantarum.