Bunch of Tulsi Plants .
Ocimum tenuiflorum, holy basil (also tulsi, tulasī), is an aromatic plant in the family Lamiaceae which is native throughout the Old World tropics and widespread as a cultivated plant and an escaped weed.
It is an erect, much branched subshrub, 30–60 cm tall with hairy stems and simple, opposite, green leaves that are strongly scented. Leaves have petioles, and are ovate, up to 5 cm long, usually slightly toothed. The flowers are purplish in elongate racemes in close whorls.
The two main morphotypes cultivated in India and Nepal are green-leaved (Sri or Lakshmi tulsi) and purple-leaved (Krishna tulsi).
Tulsi is cultivated for religious and medicinal purposes, and for its essential oil. It is widely known across South Asia as a medicinal plant and an herbal tea, commonly used in Ayurveda, and has an important role within the Vaishnavite tradition of Hinduism, in which devotees perform worship involving tulsi plants or leaves.
The variety of Ocimum tenuiflorum used in Thai cuisine is referred to as Thai holy basil, or kraphao ; it is not be confused with Thai basil, which is a variety of Ocimum basilicum.
Recent studies suggest tulsi may be a COX-2 inhibitor, like many modern painkillers, due to its high concentration of eugenol (1-hydroxy-2-methoxy-4-allylbenzene).
One study showed it to be an effective treatment for diabetes by reducing blood glucose levels. The same study showed significant reduction in total cholesterol levels with tulsi. Another study showed its beneficial effect on blood glucose levels is due to its antioxidant properties. Tulsi also shows some promise for protection from radiation poisoning and cataracts. The fixed oil has demonstrated antihyperlipidemic and cardioprotective effects in rats fed a high fat diet Experimental studies have shown an alcoholic extract of tulsi modulates immunity, thus promoting immune system function. Some of the main chemical constituents of tulsi are: oleanolic acid, ursolic acid, rosmarinic acid, eugenol, carvacrol, linalool, β-caryophyllene, β-elemene (c.11.0%), β-caryophyllene (about 8%), and germacrene D (aboutv2%). β-Elemene has been studied for its potential anticancer properties, but human clinical trials have yet to confirm its effectiveness.
O. sanctum extracts are antibacterial (against E. coli, S. aureus and P. aeruginosa).