Classification (APG IV)
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Lamiales
Family: Lamiaceae
Genus: Ocimum
Species: Tulsi - Ocimum tenuiflorum L.

Botanical description
Tulsi (Ocimum tenuiflorum), also known as holy basil, is an erect, aromatic, bushy perennial plant in the Lamiaceae family. The plant grows to a height of 30–60 cm and has stems and leaves covered with hairs of varying lengths. The leaves are green or purple-tinted, simple, ovate, sharp-tipped, with serrated edges, and up to 5 cm long. The flowers are purple, bilabiate, and arranged in dense, whorled verticillasters around the stem, with up to ten flowers per whorl. The perianth is double and pentamerous, and the corolla is bilabiate. There are four stamens, two longer and two shorter. The ovary is bicarpellary and four-chambered. The fruit is composed of dried sepals that enclose four nutlets. [1]

There are three main morphological types:

1. Ram Tulsi: The most common type, with broad, bright green leaves and a slightly sweet flavor.

2. Krishna or Shyam Tulsi: Less common, with purple-green leaves.

3. Vana Tulsi: Ocimum gratissimum, a wild type. [1]

Distribution
Tulsi is widespread in tropical and subtropical regions of Asia, Australia, and the western Pacific. It is extensively cultivated across Southeast Asia's tropics. [2] In tropical America, it has become naturalized and, in some areas, invasive. [4]

Effects and Uses
Tulsi is known to reduce stress and strengthen the immune system. It helps regulate blood sugar and blood pressure and has anti-inflammatory, antibacterial, stress-relieving, and digestive health-promoting properties. Studies suggest that tulsi consumption may enhance memory, cognitive abilities, and alleviate depression and anxiety. [4] Daily use of tulsi, whether as a dried herb or in food, is believed to help prevent various health issues, though many claims require further clinical validation. [2,3,4]

Tulsi is widely used in agriculture and traditional Southeast Asian cuisine. The plant is highly aromatic and used primarily in cooking. Its seeds are added to beverages for a gelatinous texture and to aid digestion. Tulsi also has cultural and religious significance. [4]

Tulsi herb and its essential oil contain tannins, flavonoids, eugenol, caryophyllene, carvacrol, linalool, camphor, and cinnamyl acetate. A study identified a group of ten neolignans, named tulsinols A–J. Dominant aromatic compounds in the essential oil include camphor, eucalyptol, ⍺-bisabolene, eugenol, germacrene, and β-bisabolene. [6,7]

References
1. Warrier, P. K. (1995). Indian Medicinal Plants. Orient Longman. ISBN 978-0-86311-551-6.
2. Kothari, S. K., Bhattacharya, A. K., Ramesh, S., Garg, S. N., & Khanuja, S. P. S. (2005). Volatile Constituents in Oil from Different Plant Parts of Methyl Eugenol-Rich Ocimum tenuiflorum. Journal of Essential Oil Research, 17(6), 656–658. https://doi.org/10.1080/10412905.2005.9699025.
3. Beltrán-Noboa, A., et al. (2022). Metabolomic Profile and Computational Analysis for the Identification of Anti-Inflammatory Mechanisms in Ocimum Plants. Food and Chemical Toxicology, 164, 113039. https://doi.org/10.1016/j.fct.2022.113039.
4. Cohen, M. M. (2014). Tulsi - Ocimum sanctum: A Herb for All Reasons. Journal of Ayurveda and Integrative Medicine, 5(4), 251–259. https://doi.org/10.4103/0975-9476.146554.
5. Jamshidi, N., & Cohen, M. M. (2017). The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review. Evidence-Based Complementary and Alternative Medicine, 2017, 9217567. https://doi.org/10.1155/2017/9217567.
6. Yamani, H. A., et al. (2016). Antimicrobial Activity of Tulsi Essential Oil and Major Constituents Against Bacteria. Frontiers in Microbiology, 7, 681. https://doi.org/10.3389/fmicb.2016.00681.
7. Padalia, R. C., & Verma, R. S. (2011). Comparative Volatile Oil Composition of Four Ocimum Species from Northern India. Natural Product Research, 25(6), 569–575. https://doi.org/10.1080/14786419.2010.482936.

Süstemaatiline kuuluvus (APG IV)
Riik: Taimed (Plantae)
Klaad: Soontaimed (Tracheophyta)
Klaad: Katteseemnetaimed (Angiospermae)
Klaad: Päriskaheidulehelised (Eudicotyledonae)
Selts: Iminõgeselaadsed / Lamiales
Sugukond: Huulõielised / Lamiaceae
Perekond: Basiilik / Ocimum
Liik: Tulsi / Ocimum tenuiflorum L.

Botaaniline kirjeldus
Tulsi on püstine, vastakalt paljuharunev põõsasjas aromaatne taim huulõieliste sugukonnast, perekonnast basiilik. Taim kasvab 30-60 cm kõrguseks. Nii varred kui lehed on kaetud erineva pikkusega karvadega. Lehed on rohelised või purpurse tooniga; need on lihtsad, munajad, teravtipulised, tavaliselt harvahambulise saagja servaga, ning kuni 5 cm pikad. Lillad huulõied on paigutatud tihedatesse ümber varre keerduvatesse männasjatesse õisikesse. Õisi männases kuni kümme. Õiekate on kaheli, viietine. Õiekroon on huuljas. Tolmukaid neli, kaks pikemad, kaks lühemad. Emakas kaheviljalehine, neljakambriline. Vilja moodustavad kuivanud tupplehed, mis peidavad endas nelja pähklikest. [1]

Peamiselt on levinud kolm morfoloogiliselt erinevat rühma: Ram tulsi (kõige tavalisem tüüp, millel on laiad erkrohelised lehed, mis on kergelt magusamaitselised), vähem levinud on purpurroheliste lehtedega Krishna või Shyam tulsi ning vana tulsi (Ocimum gratissimum). [1]

Levila
Taim on levinud Austraalias, Aasias ja Vaikse ookeani lääneosa troopilistes ja subtroopilistes piirkondades. Seda kasvatatakse laialdaselt kogu Kagu-Aasia troopikas. [2] Troopilises Ameerikas esineb ka metsistunud, kohati invasiivse  võõrliigina. [4]

Toime ja kasutamine
Taim aitab leevendada stressi ja tugevdab immuunsüsteemi. Lisaks sellele aitab tulsi normaliseerida veresuhkrut ja vererõhku. Sellel on põletikuvastane, antibakterioaalne, stressi leevendav ning seedesüsteemi tervist toetav.  On tehtud uuringuid, mis näitavad, et tulsi tarvitamine võib parandada mälu ning kognitiivseid võimeid ja aitab leevendada depressiooni ning ärevust. [4] Lisaks näitavad uuringud, et tulsi igapäevane droogina tarvitamine või lisamine toidule aitab ennetada mitmesuguste terviseprobleemide esinemist, kuid paljud väited vajavad edasist kliinilist hindamist. [2, 3, 4]

Taim on oluline põllumajanduses ning on osa Kagu-Aasia tradistioonilisest köögist. Tulsi on väga aromaane - taime kasutatakse peamiselt kulinaarias. Seemneid lisatakse jookidele klimbise tekstuuri andmiseks ja seedimise parandamiseks. Taim leiab kasutust ka religioossetes praktikates. [4] 

Tulsi ürt ja selle õli sisaldavad tanniine, flavonoide, eugenooli, karüofülleene, karvakrooli, linalooli, kamforit ja tsinnamüülatsetaati. Ühes uuringus avastati 10 neoliiganaani rühm, mida nimetatakse tulsinooliks A-J. Olulised õlis domineerivad aromaatsed ühendid on kamfor, eukalüptool, ⍺-bisaboleen, eugenool, germakreen ja β-bisaboleen.  [6, 7]

Kasutatud allikad
1. Warrier, P. K. (1995). Indian Medicinal Plants. Orient Longman. ISBN 978-0-86311-551-6.
2. Kothari, S. K., Bhattacharya, A. K., Ramesh, S., Garg, S. N., & Khanuja, S. P. S. (November–December 2005). Volatile Constituents in Oil from Different Plant Parts of Methyl Eugenol-Rich Ocimum tenuiflorum L.f. (syn. O. sanctum L.) Grown in South India. Journal of Essential Oil Research, 17(6), 656–658. doi:10.1080/10412905.2005.9699025. S2CID 95551382.
3. Beltrán-Noboa, A., Proaño-Ojeda, J., Guevara, M., Gallo, B., et al. (2022). Metabolomic profile and computational analysis for the identification of the potential anti-inflammatory mechanisms of action of the traditional medicinal plants Ocimum basilicum and Ocimum tenuiflorum. Food and Chemical Toxicology, 164, 113039. https://doi.org/10.1016/j.fct.2022.113039.
4. Cohen M. M. (2014). Tulsi - Ocimum sanctum: A herb for all reasons. Journal of Ayurveda and integrative medicine, 5(4), 251–259. https://doi.org/10.4103/0975-9476.146554
5. Jamshidi, N., & Cohen, M. M. (2017). The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature. Evidence-based complementary and alternative medicine : eCAM, 2017, 9217567. https://doi.org/10.1155/2017/9217567
6. Yamani, H. A., Pang, E. C., Mantri, N., & Deighton, M. A. (2016). Antimicrobial Activity of Tulsi (Ocimum tenuiflorum) Essential Oil and Their Major Constituents against Three Species of Bacteria. Frontiers in Microbiology, 7, 681.  https://doi.org/:10.3389/fmicb.2016.00681 
7. Padalia, R. C., & Verma, R. S. (2011). Comparative volatile oil composition of four Ocimum species from northern India. Natural Product Research, 25(6), 569–575.  https://doi.org/:10.1080/14786419.2010.482936