Ocimum sanctum is from the Lamiaceae family. It is commonly known as tulsi or holy basil, and should not be confused with sweet basil or Ocimum basilicum, which also belongs to the Lamiaceae family and is used in Italian and Asian foods (Ulbricht, 2010). Other common names for tulsi include basilici herba, common basil, garden basil, green holy basil, hot basil, Indian basil, kala tulsi, Ocimum tenuiflorum, Rama tulsi, sacred basil, Thai basil, and vicenin (Petersen, 2014; Ulbricht, 2010). In Sanskrit, tulsi means the incomparable one, and in India, tulsi is known as the queen of herbs and Mother medicine of nature (Cohen, 2014; Mandal, Mandal, & Pal, 2012; Ulbricht, 2010). The herb is native to India and other parts of Asia, but can be found globally (Ulbricht, 2010).
Every part of the tulsi plant has beneficial properties, but the components found in the leaves are the most studied. Leaves are a source of volatile oils or essential oils and ethanolic extracts (Shimizu et al., 2013). The main active constituent is eugenol, which provides much of the therapeutic activity to the herb (Mandal et al., 2012). Tulsi also contains alkaloids, ascorbic acid, camphor, carvacrol, flavonoids, glycosides, linalool, manganese, methyl chavicol, methyl eugenol, phenols, proteins, resins, saponins, sodium, steroids, tannins, triterpenoids, ursolic acid, vitamin A, vitamin C, and zinc (Balakumar, Rajan, Thirunalasundari, & Jeeva, 2011; Inbaneson, Ravikumar, Suganthi, 2012; Mandal et al., 2012; Petersen, 2014). The essential oil is a good source of eugenol and methyl eugenol, alpha and beta-caryophyllene, carvacrol, linalool, germacrene A, beta-ocimene, and cinnamyl acetate (Petersen, 2014b).
Tulsi was used for its medicinal and spiritual properties and often considered the “elixir of life” (Cohen, 2014, p. 252). In India it was and is used in religious ceremonies, and to protect homes (Ulbricht, 2010). In Ayurveda, it dried tissues, managed stress, prepared the body for spiritual rituals, prevented illness, reduced fever, treated colds, treated skin conditions, and promoted health, wellbeing, and longevity (Cohen, 2014; Ulbricht, 2010). It was used in the Siddha system of medicine to treat conditions affecting the skin and liver, and as an antidote for snake and scorpion bites (Shimizu et al., 2013). In Traditional Chinese Medicine (TCM), tulsi was a spasmolytic for the stomach, provided kidney support, increased circulation, and treated snake and insect bites (Ulbricht, 2010).
Tulsi improves complexion, and fosters beauty, calmness, intelligence, and stamina (Cohen, 2014). It is used to heal wounds, lower blood glucose and lipid levels, protect against eye infections, and treat allergies, arthritis, asthma, back pain, bad breath, cardiac conditions, diarrhea, dysentery, gastric disorders, genitourinary disorders, hiccups, indigestion, malaria, mouth sores, ringworm, sore throat, ulcers, and vomiting (Cohen, 2014; Shimizu et al., 2013; Ulbricht, 2010). Tulsi is an adaptogenic, analgesic, anthelmintic, anti-carcinogenic, anticatarrh, anti-diabetic, anti-inflammatory, antioxidant, antimicrobial, antipyretic, antitussive, carminative, demulcent, expectorant, galactagogue, hepatoprotective, immunomodulator, and radioprotective (Hoffman, 2003; Shimizu et al., 2013; Ulbricht, 2010).
The Food and Drug Administration (FDA) considers tulsi as Generally Recognized As Safe or GRAS. However, it should be used with caution by those taking blood sugar medications or those with hypoglycemia or diabetes (Ulbricht, 2010). There are reports holy basil has anti-fertility effects, and should be avoided by women trying to conceive (Petersen, 2014).
Standard doses vary from 1 to 2.5 g of dried herb (Petersen, 2014). As a preventative and health promoter 300 to 2,000 mg should be consumed daily, and as a therapeutic 600 to 1,800 mg should be consumed daily (Ulbricht, 2010). Tulsi tea can be prepared with 2 g of herbs (Ulbricht, 2010). It can be consumed as a dried herb, extract, food, or supplement. Specific dosages, possible contra-indicatory effects, and drug interactions should be reviewed with a health care provider.
Tulsi has been studied in animal and human studies, and been found to be an effective adaptogenic, analgesic, anti-carcinogenic, anti-cataract, anticoagulant, antidiabetic, anti-diarrheal, antiemetic, anti-hypercholesterimic, antihypertensive, anti-inflammatory, antimicrobial, antioxidant, antitussive, cardioprotective, chemoprotective, diaphoretic, hepatoprotective, immunomodulatory, insect repellant, memory enhancer, neuroprotective, radioprotective, and spasmolytic (Cohen, 2014). It has been used to prevent arthritis, allergies, asthma, and ulcers (Cohen, 2014).
An in vitro study determined that ethanolic exctract from tulsi at a concentration of 800 µg / mL and essential oil of tulsi at 1% vol / vol inhibited the proliferation of pancreatic cancer cells (Shimizu et al., 2014). Tulsi decreased the motility of cells, invaded them, and decreased the size of the tumor. The ethanolic extract was 20 to 40 times more effective than the essential oil. However, when tested in mice, the same effects were present, but were not as strong (Shimizu et al., 2014).
Another study found that a 95% ethanol extract of tulsi enhanced antioxidant enzymes and displayed anti-metastatic activity. A follow-up study showed ethanolic extract from tulsi significantly reduced osteoponin, a glycoprotein involved in tumor migration and metastasis; prevented adhesion of lung cancer cells, which is a component of metastasis; and inhibited some metabolic pathways associated with cancer (Kwak et al., 2014). Tulsi is also effective in preventing cancer by reducing damage within DNA and aiding in the apoptosis of precancerous and cancerous cells (Cohen, 2014).
Extracts of tulsi have antibacterial activity against Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and others. A study showed that an extract of 50 g of dried herb in 50% ethanol had antibacterial activity against Salmonella enterica, the bacteria that cause typhoid fever that is resistant to antibiotic treatments (Mandal et al., 2012). Whole plant extracts showed activity against Plasmodium falciparum, the parasite that causes malaria (Inbaneson et al., 2012). Leaf extracts and essential oil of tulsi also showed antifungal activity against dermatophytic fungi, such as Trichophyton mentagrophytes, Microsporum canis, and Epidermophyton floccosum (Balakumar et al., 2011).
Tulsi has antioxidant effects and helps the body to prevent and fight damage caused by toxins. The black or purple variety of tulsi, known as Krishna tulsi, is the most effective due to its high phenolic content (Cohen, 2014). Other constituents that offer an antioxidant effect are glutathione, superoxide dismutase, and catalase. Tulsi helps the body get rid of toxins by enhancing the effect of cytochrome P450 enzymes, which support the liver and kidneys in deactivating toxic chemicals and excreting them from the body (Cohen, 2014). Tulsi’s constituents reduce damage from heavy metals, industrial chemicals, pesticides, pharmaceuticals, and radiation (Cohen, 2014).
Natural Medicines, formerly known as Natural Standard, gave a grade C to evidence that tulsi is effective in reducing blood sugar levels and treating diabetes mellitus (Ulbricht, 2010). A grade C indicates that the evidence is unclear or conflictive. A study over a 30 day period on diabetes patients showed a 26.4% reduction in plasma glucose after administering a 200 mg / kg of tulsi extract on a daily basis (Petersen, 2014).
All these studies indicate why tulsi was known as the elixir of life.
Balakumar, S., Rajan, S., Thirunalasundari, T., & Jeeva, S. (2011). Antifungal activity of Ocimum sanctum Linn. (Lamiaceae) on clinically isolated dermatophytic fungi. Asian Pacific Journal of Tropical Medicine, 4(8), 654-657. doi:10.1016/S1995-7645(11)60166-1.
Cohen, M. M. (2014). Tulsi – Ocimum sanctum: a herb for all reasons. Journal of Ayurveda and Integrative Medicine, 5(4), 251-259. doi:10.4103/0975-9476.146554
Hoffman, D. (2003). Medical Herbalism, The Science and Practice of Herbal Medicine. Rochester, VT: Healing Arts Press.
Inbaneson, S. J., Ravikumar, S., & Suganthi, P. (2012). In vitro antiplasmodial effect of ethanolic extracts of traditional medicinal plant Ocimum species against Plasmodium falciparum. Asian Pacific Journal of Tropical Medicine, 5(2), 103-106. doi:10.1016/S1995-7645(12)60004-2
Kwak, T. K., Sohn, E. J., Kim, S., Won, G., Choi, J. U., Jeong, K., Jeong, M., Kwon, O. S., & Kim, S. H. (2014). Inhibitory effect of ethanol extract of Ocimum sanctum on osteopontin mediated metastasis of NCI-H460 non-small cell lung cancer cells. BMC Complementary and Alternative Medicine, 14(419), 1-10. Retrieved from http://www.biomedcentral.com/1472-6882/14/419
Mandal, S., Mandal, M. D., & Pal, N. K. (2012). Enhancing chloramphenicol and trimethoprim in vitro activity by Ocimum sanctum Linn. (Lamiaceae) leaf extract against Salmonella enterica serovar Typhi. Asian Pacific Journal of Tropical Medicine, 5(3), 220-224. doi:10.1016/S1995-7645(12)60028-5.
Petersen, D. (2014). Herb 503 Advanced Herbal Materia Medica II. Portland, OR: American College of Healthcare Sciences.
Shimizu, T., Torres, M. P., Chakraborty, S., Souchek, J. J., Rachagani, S., Kaur, S., Macha, M., Ganti, A. K., Hauke, R. J., & Batra, S. K. (2013). Holy basil leaf extract decreases tumorigenicity and metastasis of aggressive human pancreatic cancer cells in vitro and in vivo: potential role in therapy. Cancer Letters, 336(2), 270-280. doi:10.1016/j.canlet.2013.03.017.
Ulbricht, C. E. (2010). Natural Standard: Herb & Supplement Guide- An Evidence-Based Reference. St. Louis, MO: Elsevier Mosby.