African basil
StarOcimum gratissimum
Western Herbalism Properties
Traditional Uses
In Caribbean and Latin American folk medicine the leaves of Ocimum gratissimum (albahaca de clavo, alfavaca) are taken as an aromatic infusion for fever, cough, headache, colic, indigestion and diarrhea, and applied externally as a wash for skin eruptions, fungal infections and as an insect repellent (Liogier, 1990; Morton, 1981).
Gallery
Botanical Description
Ocimum gratissimum, clove basil, African basil or scent leaf, is an aromatic perennial subshrub in the mint family Lamiaceae growing 1 to 3 meters tall on square woody-based stems. The opposite leaves are ovate-lanceolate, 5 to 15 centimeters long, with serrate margins, soft pubescence on both surfaces and a strong clove-like aroma derived chiefly from eugenol in the essential oil. Small two-lipped greenish-white to pale yellow flowers are borne in slender terminal racemose panicles up to 20 centimeters long, followed by tiny dark nutlets. The species is native across tropical Africa, Madagascar, southern Asia and the Bismarck Archipelago and has naturalized widely through Polynesia, Hawaii, Mexico, Panama, the West Indies, Brazil and Bolivia. The leaves are prized as a culinary herb across West Africa (the Nigerian "scent leaves" of pepper soup) and contain polyphenols (gallic and rosmarinic acids), flavonoids (quercetin, rutin) and an eugenol-rich essential oil with documented antibacterial and anti-leishmanial activity.
Active Constituents
Eugenol
Phenylpropanoid (phenolic volatile)Concentration: Often a major essential-oil component (chemotype-dependent, can exceed 40-70%)
The clove-like principal volatile of many O. gratissimum populations. Confers strong antimicrobial, antifungal, analgesic and anti-inflammatory activity and is a main driver of the plant's medicinal effects.
Thymol
Monoterpene phenolConcentration: Major in thymol-chemotype oils
A phenolic monoterpene with potent antibacterial and antifungal activity; in some chemotypes it dominates the oil and largely accounts for antimicrobial action against enteric pathogens.
1,8-Cineole (eucalyptol)
Monoterpene etherConcentration: Variable minor-to-moderate
Contributes expectorant, bronchodilatory and anti-inflammatory activity underlying traditional use for coughs and respiratory complaints.
β-Caryophyllene
SesquiterpeneConcentration: Common minor-to-moderate oil component
A dietary cannabinoid-receptor (CB2) agonist sesquiterpene with anti-inflammatory and analgesic properties.
Rosmarinic acid and caffeic/chlorogenic acids
Hydroxycinnamic acid derivativesConcentration: Principal polyphenols of leaf extracts
Water-soluble antioxidants that provide much of the free-radical-scavenging and anti-inflammatory activity of aqueous leaf preparations.
Flavonoids (luteolin, apigenin, quercetin, rutin, nevadensin, vicenin)
Flavones / flavonolsConcentration: Minor
Contribute to antioxidant, anti-inflammatory and reported antidiabetic and hepatoprotective activities of the leaf.
Ursolic and oleanolic acids
Pentacyclic triterpenoidsConcentration: Minor
Triterpene acids associated with anti-inflammatory, antimicrobial and metabolic effects in preclinical studies.
⚠ Drug Interactions
Antidiabetic medicines (insulin, sulfonylureas, metformin)
Leaf extracts consistently lower blood glucose in animal models, partly by inhibiting intestinal glucose transport, which could add to glucose-lowering drugs.
Clinical note: Monitor blood glucose if used medicinally with antidiabetic therapy; watch for hypoglycaemia.
Antihypertensive drugs
Reported hypotensive/vasorelaxant activity of the plant could add to antihypertensive medication.
Clinical note: Monitor blood pressure with regular medicinal use alongside antihypertensives.
Antiplatelet and anticoagulant drugs (aspirin, clopidogrel, warfarin)
Eugenol, a major constituent, inhibits platelet aggregation in vitro, giving a theoretical additive antiplatelet effect at high intake of concentrated preparations.
Clinical note: Culinary use is not a concern; caution with concentrated essential oil in patients on antithrombotic therapy.
Preparation Methods
Leaf infusion / tea
Parts: leaves
Fresh or dried leaves are steeped in hot water and drunk for coughs, colds, fevers and digestive upset, and consumed as a health tea (as on Ishigaki Island, Japan). Typically a handful of leaves per cup, taken once or twice daily.
Steam inhalation / decoction
Parts: leaves, flowering tops
Leaves are boiled and the aromatic steam inhaled for nasal congestion and respiratory complaints; the warm decoction is also used as a wash for skin infections.
Essential oil (topical, diluted)
Parts: leaves (steam-distilled oil)
The eugenol/thymol-rich oil is used, diluted in a carrier oil, as a topical antimicrobial and analgesic. Phenol-rich oil can irritate skin and mucosa and should not be taken internally without professional guidance; avoid in pregnancy.
Culinary herb / scent leaf
Parts: leaves
Widely used fresh as a flavouring ('scent leaf') in West African cooking, providing a mild everyday dietary intake of its aromatic constituents.
Clinical Studies
A review on the traditional uses, phytochemistry, and pharmacological activities of clove basil (Ocimum gratissimum L.)
Comprehensive review collating the essential-oil and polyphenol chemistry of O. gratissimum and its antioxidant, anti-inflammatory, antimicrobial, antidiabetic, antihypertensive and hepatoprotective activities, which remain largely supported by in vitro and animal evidence rather than randomized human trials.
Anti-Diabetic Potential of Ocimum gratissimum Leaf Fractions in Fortified Diet-Fed Streptozotocin Treated Rat Model of Type-2 Diabetes
Leaf fractions of clove basil produced dose-dependent reductions in blood glucose and improved metabolic parameters in a diet/streptozotocin rat model of type-2 diabetes, supporting traditional antidiabetic use.
Historical Texts
Ayurvedic tradition (as 'Ram Tulsi' / Vana Tulsi complex)
Classical to modern Indian ethnomedicineWest African and Nigerian ethnomedicine ('scent leaf'/'efirin', 'nchanwu')
Traditional, documented in modern ethnobotanical surveysReferences
- Ugbogu OC, Emmanuel O, Agi GO, et al.. A review on the traditional uses, phytochemistry, and pharmacological activities of clove basil (Ocimum gratissimum L.) . Heliyon (2021) [DOI]
- Melo RS, et al.. Characterization of essential oil from Ocimum gratissimum leaves: Antibacterial and mode of action against selected gastroenteritis pathogens . Microbial Pathogenesis (2019) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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