History:
Turmeric has been used in Indian systems of medicine for a long time. It is listed in an Assyrian herbal dating from about 600 BC and is also mentioned by Dioscorides. Both the East and the West have held its medicinal properties in high regard.

Distribution:
The plant is a native of southern Asia (probably India) and is cultivated extensively throughout the warmer parts of the world.

Habit:
C.longa is a perennial herb, with a short stem and tufted leaves. The rhizomes, which are short and thick, constitute the turmeric of commerce. 

Phytochemistry:
The rhizomes contain curcuminoids, curcumin, demethoxy curcumin, bis- demethoxycurcumin, 5'- methoxycurcumin and dihydrocurcumin which are found to be natural anti-oxidants. A new curcuminoid, cyclocurcumin, was isolated from the nematocidally active fraction of turmeric. The fresh rhizomes also contain two new natural phenolics which possess antioxidant and anti-inflammatory activities and also two new pigments. Several sesquiterpenes, germacrone, turmerone, ar-(+)-, a-, ß- turmerones; ß- bisabolene; a-curcumene; zingiberene; ß- sesquiphellandene, bisacurone; curcumenone; dehydrocurdione; procurcumadiol; bis-acumol; curcumenol; isoprocurcumenol epiprocurcumenol; procurcumenol; zedoaronediol; curlone; and turmeronol A and turmeronol B, have been recorded from the rhizomes. The rhizomes are also reported to contain four new polysaccharides-ukonans - having activity on the Reticuloendothelial system, along with stigmasterol, ß-sitosterol, cholesterol and 2-hydroxymethyl anthraquinone. (Ravindranath & Satyanarayana, Phytochemistry, 1980, 19, 2031; Masuda et al, ibid, 1993, 32, 1557; Toda et al, Chem Pharm Bull, 1985, 33, 1725; Kiuchi et al, ibid, 1993, 41, 1640; Nakayama et al, Phytochemistry, 1993, 33, 501; Ohshiro et al, ibid, 1990, 29, 2201; Golding et al, J Chem Soc, Chem Commun, 1982, 363; Uehara et al, Shoyakugaku Zasshi, 1992, 46, 55; Kiso et al, Phytochemistry, 1983, 22, 596; Imai et al, Agric Biol Chem, 1990, 54, 2367; Gonda et al, Chem Pharm Bull, 1990, 38, 482; 1992, 40, 185; Chem Abstr, 1977, 87, 11482; Ogbeide et al, Pak J Sci, 1985, 37, 15).

The essential oil from the rhizome contains d-a-phellandrene, d-sabinene, cineol, borneol, zingiberene, sesquiterpenes (turmerones), (Kelkar & Rao. J. Indian Inst. Sci.,1933, 17A, 7). A ketone, and an alcohol identified as p-tolylmethyl carbinol, have been obtained distillate (Chem. Abstr., 1933, 27, 4876). The crystalline coloring matter, curcumin, is a diferuloyl methane. It dissolves in concentrated sulphuric acid giving a yellow-red coloration. (Mayer & Cook,93; Chem. Abstr.,1948,42,8496).                      a-Phellandrene

Pharmacology:
Turmeric possesses anti-inflammatory property. Petroleum ether extracts of the rhizome showed significant anti-inflammatory activity in experimental animals without producing any toxicity or side effects. The anti-inflammatory activity of turmeric extracts has been attributed to curcumin and its analogues [Choudhury & Haq, Bull Med-Ethno-Bot Res, 1980, 1, 408; Arora et al, Indian J Med Res, 1971, 59, 2189; Ammon & Wahl, Planta Med, 1991, 57, 1; Rao et al, Indian J Med Res, 1982, 75, 574; Khung et al, Indian J Pharmacol, 1986, 18, 20; Srimal & Dhawan, J Pharm Pharmacol, 1973, 25, 447; Srimal, Indian Spices, 1993, 30 (2&3), 21; Dhawan, ibid, 1993, 30 (2&3), 19; East Pharm, 1979, 22 (258), 70; Sinha et al, Nagarjun, 1976, 19 (6), 11].

Oil of C.longa leaves obtained by steam distillation was given orally to study its effects on the exudative and proliferative phases of the inflammatory reaction, using the techniques of carrageenin-induced paw edema and cotton pellet methods in male albino rats. The anti-inflammatory activity was compared with Phenylbutazone. In carrageenin- induced edema, 1.6ml/kg of the volatile oil had as much anti-inflammatory activity as that of 100 mg/kg Phenylbutazone. The oil was also found to be potent in cotton pellet granuloma studies (Iyengar, M.A et al., Indian Drugs, 1994, v., 31(11), 528-531).

An oral dose of 500 mg/kg of the ethanol extract of turmeric produced significant antiulcerogenic activity in rats subjected to hypothermic-restraint stress and pyloruic ligation. It also showed marked anti-ulcerogenic effect in indomethacin and reserpine, induced-gastric ulcers in rats. The extract had a highly significant protective effect against cytodestructive agents. Turmeric extract not only increased the gastric wall mucus significantly but also restored the non-protein sulfhydryl (NP-SH) content in the glandular stomachs of the rats (Rafatullah, S. et al., J. Ethnopharmacol., 1990, v., 29(1), 25-34).

C.longa rhizome extract showed blood glucose lowering activity in experimental, induced- diabetic rats. After 3 and 6 hrs of curcuma injection (10 mg), 37.2 percent and 54.5 percent fall, were observed respectively in the glucose levels (Tank, R. et al., Indian Drugs, 1990, v., 27(11), 587-589).

Turmeric is reported to have anti-fertility activity as observed with experimental animals. The petroleum ether and aqueous extracts showed 100 percent anti-implantation in rats at a dose of 200 mg/kg body wt fed orally on day 1 to 7 of pregnancy (Choudhury & Haq, Bull Med-Ethno-Bot Res, 1980, 1, 408; Garg et al, Indian J Exp Biol, 1978, 16, 1077; Garg, Planta Med, 1974, 26, 225; Curr Res Med Arom Pl, 1983, 5, 83-01-549).

Clinical studies:
Of the 50 cases of conjunctivitis, 25 cases were treated with Haridra Eye drops (HEB) and other 25 cases with soframycin eye drops (SED). Clinical symptoms started subsiding from the 3rd day and all were cured by the 6th day (except 2 patients) in patients treated with HED. In SED patients symptoms subsided from the 4th day and complete relief took 7 days except for 2 cases, which took 9 days. This indicates that HED has a definite role in conjunctivitis. Bacteriological study shows that Haridra act, effectively on E.coli, Staphylococus aureus, Klebsella and Pseudomonas (Srinivas,C. and Prabhakaran,K.V.S., Ancient Science of Life, 1989, v., 8(3 & 4), 279-283).

The Volatile oil of C.longa when given orally, was found most effective in the treatment of bronchial asthma than when given intramuscularly (Jain,J.P. et al. J. Res. Ayur. and Siddha, 1990, v., 11(1-4), 20-30).

Toxicity:
The clastogenic potential of Curcuma longa in experimental rats in in vivo conditions has been evaluated. A single acute dose treatment (500 mg/kg b.w.) could not significantly induce micronucleated polychromatic erythrocytes but caused considerably higher chromosomal abberrations (Jain, A.K.et al., Curr. Sci., 1987, 56(19), 1005-1006).

Indications:
In Indian systems of medicine, turmeric is used to some extent as a stomachic, tonic and blood purifier. It is also prescribed as an antiperiodic alterative. Externally, it is applied to indolent ulcers. A decoction of the rhizome is said to relieve the pain of purulent ophthalmia. Oil of turmeric, distilled from the dried rhizomes, has feeble antiseptic properties. It is an antacid, and, in small doses, acts as a carminative, stomachic, appetiser and tonic. In large doses, however, it appears to act as an antispasmodic inhibiting excessive peristaltic movements of the intestines. Turmeric also possesses anti-inflammatory property.Eur J Med Res 1997;2:37-43.