Holy Basil
Scientific Name(s): Ocimum sanctum L., Ocimum tenuiflorum L.
Common Name(s): Ajaka, Baranda, Brinda, Holy basil, Ka prao, Kha phrao, Manjari, Monk's basil, Parnasa, Patra-puspha, Sacred basil, Suvasa, Thai basil, Thulasi, Tulasi, Tulsi
Medically reviewed by Drugs.com. Last updated on Jan 22, 2025.
Clinical Overview
Use
Limited evidence suggests potential applications in treating stress, anxiety, and diabetes. Anti-inflammatory and antimicrobial activities have also been demonstrated. However, clinical trials are lacking to recommend use for any indication.
Dosing
Limited clinical trials are available to provide dosing recommendations for holy basil.
Contraindications
Contraindications have not been identified. Hypersensitivity to any components of the plant species should be considered a contraindication.
Pregnancy/Lactation
Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking. Emmenagogue and abortifacient effects have been reported for the related species Ocimum basilicum.
Interactions
None well documented.
Adverse Reactions
Clinical information is lacking.
Toxicology
No data.
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) O. tenuiflorum is a perennial, many-branched shrub indigenous to India and parts of Africa, Taiwan, and China and cultivated in southeast Asia. It can grow up to 1 m in height. Green and purple color variants exist that are otherwise morphologically indistinguishable.
Unlike common basil, holy basil plants have slightly hairy, pale leaves that are simple, opposite, and oblong or ovate, measuring 3 to 7 cm in length and 1 to 3 cm in width. The leaves have a characteristically strong aroma, likened to that of cloves, and an astringent taste. The flowering part of the plant consists of a florescence of purple and red flowers. Related plants include O. basilicum (sweet basil), Ocimum gratissimum (African basil), Ocimum campechianum (Amazonian basil), and Ocimum canum (African mint, hoary basil).(Duke 2002, USDA 2021, WHO 2002)
History
Use of O. tenuiflorum is described in ancient Ayurvedic texts, and the plant is an important symbol in Hindu religious tradition. Holy basil has been described as an "elixir of life" and a tonic with adaptogenic properties. It has been used to promote longevity and to treat a range of conditions, including the common cold, headache, stomach complaints, inflammation, heart disease, insect or snake bites, and malaria. Holy basil is used in cooking and is consumed as a fresh leaf, an herbal tea, a dried powder, or mixed with ghee. The dried leaves can be stored with grains and used as an insect repellent. The essential oil is used in cosmetics and skin preparations.(Cohen 2014, Mondal 2009, WHO 2002)
Chemistry
O. tenuiflorum primarily contains tannins, flavonoids, and an essential oil. Gas chromatography-mass spectrometry has been used to elucidate the constituents of the essential oil, which include eugenol and methyl eugenol (up to 64%), alpha- and beta-caryophyllene, 1,8 cineole, methyl chavicol, carvacrol, linalool, thymol, limonene, gamma-terpinene, camphor, germacrene A, beta-ocimene, and cinnamyl acetate. Chemical composition varies with geographical location and other environmental and genetic factors.(Duke 1992, Mahajan 2013, Pandey 2014, Vieira 2014, WHO 2002) Additional constituents, among others, include oleanolic acid, rosmarinic acid, ursolic acid, apigenins, luteolins, cerebrosides, and acimumosides.(Mahajan 2013, Pandey 2014, Upadhyay 2015) Traces of zinc, manganese, sodium, and vitamins A and C have been identified.(Mahajan 2013)
Uses and Pharmacology
Despite traditional medicinal use of holy basil for various conditions, clinical trials examining such uses are lacking. Many therapeutic effects are attributed to the antioxidant action of the extracts and individual chemical constituents.(Mahajan 2013, Pandey 2014)
Anticancer/Radioprotection
Animal and in vitro data
In animal studies, extracts of holy basil were protective against radiation-induced DNA damage, probably via antioxidant mechanisms.(Dutta 2007, Joseph 2011, Nayak 2005, Siddique 2007, Subramanian 2005, Vrinda 2001)
In vitro studies have demonstrated activity against human cancer cell lines, including brain, lung, pancreatic, prostate, and ovarian carcinomas, as well as neuroblastoma and leukemia.(Dhandayuthapani 2015, Kwak 2014, Pandey 2015, Shimizu 2013) Anticancer activity has also been demonstrated in rodent studies.(Coeugniet 1987, Manaharan 2014, Rastogi 2007)
Anti-inflammatory activity
Animal and in vitro data
In vitro studies demonstrate possible effects of holy basil extracts on inflammatory markers,(Choudhury 2014, Manaharan 2014, Navin 2013) while in studies of rats with isoproterenol-induced myocardial infarction, pretreatment with a methanolic extract of O. tenuiflorum leaves decreased lipoxygenase and cyclooxygenase activity and leukotriene and thromboxane levels.(Kavitha 2015) In a carrageenan-induced paw edema study in rodents, the ethyl acetate root extract of holy basil was effective as an anti-inflammatory agent.(Kumar 2015)
Clinical data
A small clinical study (N=29) reported improved healing rates in mandibular fractures with administration of O. tenuiflorum (as an adaptogen; one teaspoonful taken 4 times a day for 4 weeks).(Mohammad 2014)
Antimicrobial activity
Animal and in vitro data
Extracts of holy basil, particularly those containing eugenol, have shown in vitro activity against a number of microorganisms, including Enterococcus faecalis, Salmonella enterica, and resistant strains of Neisseria gonorrhoea.(Mandal 2012, Navin 2013, Shokeen 2008) Activity against Candida albicans has also been demonstrated in vitro.(Khan 2014) Reports of efficacy against Mycobacterium tuberculosis and the parasite Leishmania donovani have been published.(Bhatter 2016, Kaur 2015b)
Inhibition of dental caries and periodontal pathogens (including Actinobacillus actinomycetemcomitans,(Eswar 2016) Streptococcus mutans, and Streptococcus sanguinis [formerly known as Streptococcus sanguis])(Kochikar 2015) has been demonstrated in several in vitro studies evaluating effects of O. sanctum.(Chandra Shekar 2015) Another study reported antimicrobial activity of an O. tenuiflorum 2% gel in the treatment of experimentally induced periodontitis in rats.(Hosadurga 2015)
Clinical data
A small clinical trial evaluated an O. tenuiflorum extract mouthwash (in polyethylene glycol and water) compared with a chlorhexidine mouthwash and placebo. Reductions in gingival bleeding and plaque indices, similar to those with chlorhexidine, were achieved with the herbal extract compared with placebo.(Gupta 2014)
A comparator study evaluated the effect of O. tenuiflorum leaf extract mouth rinse compared with sodium fluoride 0.05% rinse in 60 school children 6 to 12 years of age. After 7 days using 5 mL of mouth rinse twice daily, the O. tenuiflorum rinse led to a statistically lower salivary Streptococcus mutans count (0.289 colony-forming units [CFU]×103) than sodium fluoride (2.293 CFU×103; P<0.001). Additionally, salivary pH value was significantly increased with the rinse compared with baseline (P<0.001) but not compared with sodium fluoride.(Megalaa 2018)
Antiulcer effects
Animal data
Animal models of induced ulcers demonstrate protective and healing properties of holy basil extracts and fixed oil. Suggested mechanisms of action include antioxidant effects, lipoxygenase inhibition, histamine antagonism, and antisecretory effects.(Dharmani 2004, Goel 2005, Kath 2006, Singh 1999, WHO 2002)
Antiviral activity
Experimental data
Of 46 phytochemicals identified in the literature from O. tenuiflorum, 3 potential inhibitors of severe acute respiratory syndrome (SARS)-CoV-2 main proteases were identified in silico using simulated molecular docking and molecular dynamic studies. Vicenin, isorientin 4ʹ-O-glucoside 2"-O-p-hydroxybenzoagte, and ursolic acid were predicted to be the best docked compounds and probable inhibitors of SARS-CoV-2 main proteases. Additionally, all 3 met simulated criteria for "drug-likeness" and ADMET (absorption, distribution, metabolism, excretion, toxicity) profile, with no carcinogenic effects.(Shree 2020)
Cardiovascular
Animal data
Conflicting data exist regarding the cardioprotective properties of holy basil extracts. Positive histological and biochemical marker findings have been reported in some animal experiments.(Mohanty 2006, Sood 2006) Reductions in lipid peroxidation have also been demonstrated in animal studies.(Geetha 2004, Reddy 2008)
CNS effects
Animal and in vitro data
Experiments in rats have demonstrated a protective effect of holy basil extracts against noise-induced stress. Pretreatment with holy basil extract prevented the increases in circulating corticosterone, dopamine, and serotonin levels induced by noise exposure; other adaptogenic effects on biochemical changes in acetylcholine, acetylcholinesterase, and creatine kinase have also been reported.(Archana 2002, Giridharan 2011, Gupta 2007, Jothie Richard 2016, Samson 2007, Sembulingam 2005)
Analgesic and anticonvulsant actions have been described in animals, as well as attenuation of the effects of cerebrovascular insufficiency, induced axonal degeneration, and memory deficits.(Kaur 2015a, Khanna 2003, Malve 2014, Muthuraman 2008, Sembulingam 2005, WHO 2002) Models of Parkinson disease and induced dementia suggest potential applications of holy basil extracts.(Giridharan 2011, Siddique 2014, Venuprasad 2013) Reduced stress, similar to that with alprazolam, was observed in rats fed O. tenuiflorum in forced swim tests.(Bathala 2012)
Clinical data
In a study of healthy volunteers, an ethanolic leaf extract of holy basil 300 mg administered over 30 days improved cognition (measured by reaction times and error rates on standard tests) compared with placebo. Improvements were also observed in salivary cortisol and anxiety scores.(Sampath 2015) Limited clinical studies suggest that O. tenuiflorum improves symptoms of stress disorders compared with placebo.(Bhattacharyya 2008, Saxena 2012, Zamin 2011)
Diabetes/Metabolic syndrome
Animal data
In animal experiments, O. tenuiflorum improved lipid profiles and demonstrated antioxidant, cardioprotective, and hypoglycemic effects, suggesting a potential role in the management of metabolic syndromes.(Dusane 2012, Gamboa-Gómez 2014, Hannan 2006, Kapoor 2008, Muralikrishnan 2012, Parasuraman 2015, Reddy 2008, Singh 2016, Suanarunsawat 2011, Suanarunsawat 2016, Vats 2004) Suggested mechanisms include insulin secretory effects and reductions in insulin resistance, inhibition of alpha-glucosidase, and enhanced activity of glucokinase, hexokinase, and phosphofructokinase enzymes.(Hannan 2006, Reddy 2008, Singh 2016, Vats 2004)
Clinical data
In a 2004 Cochrane review evaluating use of traditional plants in hyperglycemia, holy basil produced a hypoglycemic response compared with placebo in 1 small trial (N=40). However, poor methodological quality related to inadequate blinding and randomization was noted, and no trials compared holy basil with pharmacological agents.(Liu 2004) A more recent, small study using holy basil extract 250 mg twice daily for 8 weeks noted statistically significant improvements in body mass index and in lipid and insulin levels in overweight and obese patients 17 to 30 years of age.(Satapathy 2017)
Insect repellent effects
In molecular modeling studies, several compounds in O. tenuiflorum have demonstrated binding to the odorant binding proteins of Anopheles gambiae, indicating potential use as mosquito repellent.(Gaddaguti 2016)
Dosing
Limited clinical trials are available to provide dosing recommendations for holy basil.
CNS disorders
A dose of 300 mg/day of an ethanolic leaf extract for 30 days was used in a study evaluating holy basil for enhancement of cognition.(Sampath 2015) An O. sanctum dosage of 1,000 mg/day for 8 weeks or an O. tenuiflorum dosage of 1,200 mg/day for 6 weeks has been used in studies evaluating the effects of holy basil extract on stress disorders.(Bhattacharyya 2008, Saxena 2012)
Diabetes/Metabolic syndrome
One small study in overweight and obese young adults evaluated effects of supplementation with O. sanctum extract (250 mg twice daily for 8 weeks) on metabolic parameters and liver enzymes.(Satapathy 2017)
Mandibular fractures
O. tenuiflorum as an adaptogen (5 mL taken 4 times a day for 4 weeks) was used in a clinical study evaluating effects on mandibular fracture healing rates.(Mohammad 2014)
Pregnancy / Lactation
Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking. Conflicting data exist regarding the embryotoxicity of O. tenuiflorum.(WHO 2002) Emmenagogue and abortifacient effects have been reported for the related species O. basilicum.(Ernst 2002) Traditional use of holy basil to increase lactation has been recorded, but safety data are lacking.(Duke 2002, WHO 2002)
Interactions
Case reports are lacking. Potentiation of the sedative effects of barbiturates has been demonstrated in experiments in rats.(Khanna 2003) Eugenol was observed to be hepatotoxic in glutathione-depleted mice; therefore, caution is recommended for concomitant use of holy basil with acetaminophen.(WHO 2002) In an epileptic rat model, administration of a hydroalcoholic leaf extract of O. tenuiflorum 30 minutes after the antiepileptic levetiracetam significantly increased the time to maximum plasma concentration for levetiracetam (P=0.009). A nonstatistically significant reduction in levetiracetam plasma levels was observed and changes in AUC, volume of distribution, half-life, and clearance were also not found to be significantly different.(Sarangi 2020)
Adverse Reactions
Data are limited. Few adverse reactions have been noted in clinical studies.(Bhattacharyya 2008, Liu 2004, Saxena 2012)
Toxicology
Clinical information is limited. Reversible inhibition of spermatogenesis and decreased total sperm count and motility have been demonstrated in rodents administered high doses of O. tenuiflorum extracts.(Ahmed 2011, Narayana 2014) In one study evaluating the acute oral toxicity and mutagenic potential of O. tenuiflorum, no treatment-related effects were reported(Chandrasekaran 2013); however, other toxicity studies report no biochemical, hematological, or histopathological changes at ethanolic leaf extract doses up to 1,000 mg/kg/day.(Gautam 2014, Raina 2015)
Index Terms
- Ocimum basilicum (sweet basil)
- Ocimum campechianum (Amazonian basil)
- Ocimum canum (African mint, hoary basil)
- Ocimum gratissimum (African basil)
References
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