Turmeric, because of its yellow color, must have attracted attention from the very early days, and it was probably used along with ginger. Haridara, as turmeric is referred to in ancient Indian Vedic texts, has been in continuous use for its coloring, flavoring, and digestive properties, and acquired additional importance when Ayurveda, the ancient, medical practice of India, was systematized by Caraca and Susruta
Turmeric and isolated compounds from turmeric have demonstrated a remarkable variety of beneficial pharmacological activities. These include antioxidant antiarthritic, antimutagenic, antitumor, anti-tumor promotion, antithrombotic antivenom by neutralizing the hemorrhagic effect of the venom in mice, antibacterial antifungal antiviral nematocidal, choleretic and antihepatotoxicactivities. Low incidence of Alzheimers disease in regions where turmeric is extensively used in cuisine and as an herbal remedy suggests that it may protect against this disease since areas of high consumption such as those in India have very low Alzheimers incidence. Further, a transgenic mouse model of Alzheimers has shown favorable response to curcumin therapy. Little or no toxicity is reported for humans receiving large (8 g/day18) therapeutic doses of curcumin, an important major component of turmeric.Turmeric, dried and cured, generally yields from 1.5 to 5% volatile oil, though few selections of agricultural research stations have recently shown values up to 7%.
Composition of turmeric oil has been studied extensively using gas chromatography (GC) and gas
chromatography-mass spectrometry (GC-MS). The oil is dominated by oxygenated sesquiterpenes,
along with small quantities of sesquiterpene hydrocarbons, monoterpene hydrocarbons and oxygenated monoterpenes. The main components are the turmerones, – (30 to 32%) and – (15 to18%), and ar-turmerone (dehydroturmerone) (17 to 26%). Turmerone is unstable in the presence of air, yielding its dimmer or the most stable ar-turmerone (Su et al., 1982).
It is shown that the aroma of turmeric is due to the sesquiterpene ketones, forming nearly 59% of the oil and identified them as ar-turmerone and tumerone occurring in the proportion of 40 and 50%. Studies have indicated that curcumin is nontoxic to humans even at a dose of 8000 mg/d taken continuously (Cheng, 2001). The medicinal uses of turmeric and curcumin are indeed diverse, ranging from cosmetic face cream to the prevention of Alzheimer’s disease. Turmeric is also qualified as the queen of natural Cox-2 inhibitors (Duke, 2003). Recent researches on turmeric are focused on its antioxidant, hepatoprotective, anti-inflammatory, anticarcinogenic, and antimicrobial properties, in addition to its use in cardiovascular and gastrointestinal disorders.
Fifteen patients receiving an extract of Curcuma (18 mg of diferuloylmethane and 2mg of the desmethoxy derivative suspended in 200 mg of essential oils derived from Curcuma spp.) at daily doses of 26–180 mg of diferuloylmethane for up to 4 months, were monitored for adverse effects by physical examination and tests for haematological parameters. In the course of the study, one patient (receiving 108 mg/day diferuloylmethane) experienced nausea and two patients (receiving 72 and 180mg/day diferuloylmethane) experienced diarrhoea. There were no reported adverse effects in a study of twenty-five patients taking diferuloylmethane (99.3%) at doses of up to 8000 mg/day for 3 months. The Committee considered that these ancillary studies could not be used to derive an ADI for curcumin.
Based upon clinical study data and some previous findings, the inhibitory action of the Curcuma rhizome-derived ar-turmerone, curcumin, and turmerone confirm their superiority and usefulness on antiplatelet agents. Taken together, curcumin and the volatile oil from Curcuma longa appear to be responsible for the well documented anti-inflammatory action in the acute and subchronic models.