Sweet Basil

Scientific Name(s): Ocimum basilicum L.
Common Name(s): Basil, Common basil, Genovese basil, Great basil, Saint-Joseph's-wort, Sweet basil

Medically reviewed by Drugs.com. Last updated on Jan 22, 2025.

Clinical Overview

Use

Animal studies of sweet basil suggest antimicrobial, insect repellent, anti-inflammatory, cardiovascular, CNS, and antidiabetic activities. O. basilicum has been investigated clinically for use in migraine headache; however, clinical studies are lacking to support use for any indication.

Dosing

Clinical studies are lacking to provide dosing recommendations for sweet basil.

Contraindications

Contraindications have not been identified. Hypersensitivity to any components of the plant species should be considered a contraindication.

Pregnancy/Lactation

Avoid use. Avoid amounts larger than those usually used in cooking. Emmenagogue and abortifacient effects have been reported for O. basilicum.

Interactions

None well documented.

Adverse Reactions

Basil as an herb and sweet basil essential oil have generally recognized as safe (GRAS) status in the United States.

Toxicology

Information is limited; the chemical constituents estragole and linalool have been associated with toxicity.

Scientific Family

• Lamiaceae (mint)

Botany

Nearly 4,000 species worldwide belong to the Lamiaceae family, and there are approximately 200 species of the genus Ocimum.(Vieira 2014) The sweet basil plant is cultivated worldwide; many varieties exist, differing in chemical composition and affected by multiple geographic factors. Sweet basil is an annual herb that grows up to 1 m in height depending on the climate, with characteristic opposite, light-green, smooth leaves that grow to 6 cm in width and 11 cm in length. The plant bears small, white flowers arranged in a terminal spike.(Khan 2010, USDA 2021) Related plants include Ocimum sanctum (holy basil), Ocimum gratissimum (African basil), Ocimum campechianum (Amazonian basil), and Ocimum canum (African mint, hoary basil). A synonym of O. basilicum is Ocimum americanum L.

History

Traditionally, O. basilicum has been used as an appetite stimulant, carminative, diuretic, and anxiolytic, as well as in cardiovascular disease and diabetes, among other conditions. Medicinal use of basil among ancient Greek and Chinese healers for promoting circulation and treating snake and insect bites has been documented. Sweet basil also has widespread culinary applications.(Bora 2011, Duke 2002, Khan 2010)

Chemistry

The major components of the volatile oil of sweet basil are linalool, cineole, and estragole (methyl chavicol), depending on the source.(Duke 1992, Scazzocchio 2016, Shirazi 2014, Vieira 2014)

Studies have elucidated the chemical composition of the essential oil and describe terpenic hydrocarbons (eg, cymene, limonene, myrecene, pinene, terpinene, phellandrene), aromatic phenols (carvacrol, eugenol, thymol, and safrol), ketones (menthone, pulegone, carvone and thujone, verbenone, and fenchone), alcohols (eg, borneol, carveol, geraniol, linalool, menthol, terpineol), aliphatic aldehydes (citral, citronellal, and perillaldehyde), acids (citronellic acid and cinnamic acid) and esters (linalyl acetate). Concentrations of these components vary depending on the source of the plant.(Bhuvaneshwari 2016, Mahajan 2013, Pandey 2014, Vieira 2014)

The seeds of the plant contain ursolic acid, rosmarinic acid, caffeic acid, vallinin, stigmasterol, apigenin, and luteolin, among other components.(Duke 1992, Mahajan 2013)

Uses and Pharmacology

Analgesic activity

Animal data

Analgesic effects of basil essential oil, primarily mediated by delta- and mu-opioid pathways, were demonstrated using various mouse pain models. No significant difference was observed between morphine and basil essential oil in the second phase of the formalin test, while basil essential oil and indomethacin reduced visceral pain by 33.15% and 47.66%, respectively, compared with the control (P=0.014 and P=0.003). At a higher dose (180 mg/kg), inhibition of thermal pain was observed (P<0.01) that was not seen with lower doses (45 mg/kg or 90 mg/kg). There were no negative effects on motor coordination when tested at the highest dose.(Bae 2020)

Anti-inflammatory activity

Animal and in vitro data

Limited animal studies report anti-inflammatory activity of O. basilicum essential oil, including via reductions in leukocytes, in rats and mice with experimentally induced colitis and arthritis, respectively; efficacy in carrageenan-induced paw edema has also been demonstrated.(Bae 2020, Rashidian 2016, Yamada 2013) Both the essential oil and the single component estragole showed efficacy in reducing histamine- and arachidonic acid–induced paw edema in mouse models.(Rodrigues 2016) Additionally, in vitro experimental studies suggest that extracts of O. basilicum or its fractions may exert an influence on cyclooxygenase enzyme activity and on prostaglandin and thromboxane production.(Amrani 2009, Umar 2014)

Antimicrobial activity

In vitro data

In vitro studies report activity of the essential oil against human and plant pathogens.(Araujo 2016, Freires 2015, Radaelli 2016, Scazzocchio 2016, Shirazi 2014, Siddiqui 2012, Sienkiewicz 2013, Snoussi 2016, Srivastava 2015)

Sweet basil essential oil was not active against fluconazole-resistant Candida spp. in an in vitro study.(Soares 2015)

Laboratory experiments suggest that the oil may be an alternative to common synthetic repellents and/or acaricides, likely due to constituents such as alpha-pinene, limonene, citronellol, citronellal, camphor, and thymol.(Cisak 2012, Inbaneson 2012, Nerio 2010, Perumalsamy 2014, Phasomkusolsil 2010, Rehman 2014)

Antiprotozoal activity has been demonstrated in vitro against Trichomonas vaginalis and Leishmania spp.(Ezz Eldin 2015, Khan 2010)

Antioxidant activity

Animal and in vitro data

Antioxidant activity has been documented in vitro and in animal studies.(Jadoon 2015, Ogaly 2015, Saha 2012, Sakr 2013, Shirazi 2014) In a transient global cerebral ischemia and reperfusion rat model, pretreatment with O. basilicum extract reduced cerebral infarct size and attenuated memory and motor coordination impairment. Antioxidant activity may contribute to these observed effects.(Bora 2011)

Asthma

Animal data

In a rat model of asthma, oral administration of basil extract significantly improved cytokine levels and inflammatory markers (ie, interferon-gamma, interleukin 4 [IL-4], immunoglobulin, phospholipase A₂, total protein) in bronchoalveolar lavage fluid compared with control rats (P<0.01 to P<0.001). Lung pathology also significantly improved with the higher basil extract concentration of 3 mg/mL (P<0.05 to P<0.01).(Eftekhar 2019)

Cancer

Animal and in vitro data

In vitro studies report activity of the essential oil against cancer cell lines, including breast and cervical cancer.(Al-Ali 2013, Behbahani 2014, Kathirvel 2012, Monga 2011, Shirazi 2014) In a study in rats, a polysaccharide from O. basilicum was noted to decrease tumor metastasis, primarily through enzyme modification.(Feng 2018)

Cardiovascular disease

Animal data

In a study in hypercholesterolemic rodents, O. basilicum extract exerted a vasorelaxant effect.(Amrani 2009) In another study in rats, O. basilicum leaf extract demonstrated protection against adverse outcomes of induced myocardial infarction (eg, ST-segment elevation, fibrosis of myocardial tissue), possibly due to its antioxidant effects.(Fathiazad 2012) Additionally, experimental studies in rodents suggest that sweet basil extracts may influence thromboxane production.(Amrani 2009, Umar 2014)

CNS effects

Animal data

In limited experiments in mice, extracts of O. basilicum demonstrated antianxiety and sedative effects,(Rabbani 2015) memory enhancement effects,(Sarahroodi 2012) and improvement in neuromuscular coordination.(Zahra 2015) An antidepressant-like effect has been described for basil essential oils in a murine model of depression induced by chronic unpredictable mild stress. Serum cortisol levels (P<0.001), brain-derived neurotrophic factor (P<0.01), and glucocorticoid receptor expression (P<0.04) improved significantly with administration of basil essential oils aromatherapy as well as the positive control (fluoxetine) compared with untreated stress controls. Significant improvements in several behavioral tests were also observed in the basil and fluoxetine groups (P<0.01 to P<0.001).(Ali 2017, Ayuob 2018)

In a study examining the same chronic unpredictable mild stress mouse model, hallmark neuropathological Alzheimer disease changes were significantly less with basil essential oil inhalation therapy and in the fluoxetine group than in untreated control mice. Memory impairment was also significantly improved in both treatment groups compared with untreated controls (P=0.001 for basil essential oil; P=0.01 for fluoxetine).(Ayuob 2018) In another chronic neurodegenerative animal model (ie, rats with ethidium bromide–induced multiple sclerosis), fresh basil emulsion administered orally for 14 days significantly improved memory deficits, inflammatory biomarkers (ie, IL-6, tumor necrosis factor alpha), astrogliosis, and mitochondrial function.(Garabadu 2020)

Diabetes

Animal and in vitro data

Limited in vitro and animal experiments suggest that the observed antidiabetic effects of O. basilicum may be due to alpha-glucosidase and alpha-amylase inhibitory activity.(El-Beshbishy 2012, Kadan 2016, Singh 2016) In rats with streptozocin-induced diabetes, all 3 basil extract doses evaluated significantly lowered blood glucose levels, with markers for endothelial function and tissue damage demonstrating no disruptions.(Widjaja 2021)

In a study evaluating the toxicity of linalool in poultry, increased serum glucose was observed; however, the researchers considered this effect to have no biological importance.(Beier 2014)

Insect repellent

Experimental data

Based on molecular docking studies performed with proteins from the Anopheles gambiae mosquito, 12 compounds from O. basilicum and other Ocimum spp. potentially have significant mosquito repellent activity.(Gaddaguti 2016)

Migraine headache

Clinical data

In a triple-blind, randomized, placebo-controlled study of Iranian adults (N=144; age range, 18 to 46 years) diagnosed with migraine for more than 1 year and who experienced more than 2 attacks per month, the interaction between dose and time factors was significant for both migraine pain intensity and frequency of attacks (P<0.001 each). Sweet basil essential oil 2%, 4%, or 8%, or placebo was applied topically to the frontal and temporal lobes every 8 hours for 3 months; all patients also received acetaminophen 325 mg every 12 hours. Compared with placebo, pain intensity decreased by 87% with basil oil 4% in week 4 and by 90% with basil oil 2% in week 8. Similarly, the rate ratio of migraine attacks that occurred was 80% lower with basil oil 4% in week 12 compared with placebo.(Ahmadifard 2019)

Dosing

Clinical studies are lacking to provide dosing recommendations for sweet basil.

Pregnancy / Lactation

Avoid use. Emmenagogue and abortifacient effects have been reported. Avoid amounts larger than those usually used in cooking.(Ernst 2002)

Excretion of cineole in breast milk has been documented, but no adverse effects were reported.(Basil 2021)

Interactions

Case reports are lacking, and the relevance of findings from in vitro and animal studies is unclear. An aqueous extract of dried aerial plant parts inhibited platelet aggregation and reduced thrombin-induced platelet activation.(Amrani 2009) An in vitro study reported CYP-450 inhibitory activity with sweet basil; however, clinical relevance has not been established.(Nguyen 2014) Eugenol was observed to be hepatotoxic in glutathione-depleted mice, leading to a cautionary note by the World Health Organization on concomitant use with acetaminophen.(WHO 2002)

Adverse Reactions

Basil as an herb and sweet basil essential oil both have GRAS status in the United States.(FDA 2021) Clinical studies are lacking regarding associated adverse effects.

Related/similar drugs

Toxicology

Information is limited; basil herb and sweet basil essential oil have GRAS status in the United States.(FDA 2021, Khan 2010) Estragole, the major chemical component of sweet basil essential oil, has been associated with hepatocellular tumors in mice and with genotoxicity.(Khan 2010) In poultry administered linalool, serum AST increased but serum gamma-glutamyltransferase did not.(Beier 2014) Hematological effects (reduced hematocrit, platelets, and red blood cells) have been observed in rats.(Rasekh 2012)

Index Terms

• Ocimum americanum L.
• Ocimum campechianum (American basil)
• Ocimum canum (African mint, hoary basil)
• Ocimum gratissimum (African basil)
• Ocimum sanctum (holy basil)

References

Disclaimer

This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

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