# Curcumin Innovative Delivery Forms: Paving the Yellow Brick Road' of Antitumoral Phytotherapy
## 1 Introduction  
### Curcumin Overview  
The history of curcumin dates back about five thousand years. This strong yellow pigment is the main active component of _Curcuma longa_, a perennial Zingiberaceae plant native to southwest India, but now grown across the South and Southeast Asia, especially in China and India [1; 2; 3]. The rhizomes of this plant are dried and powdered to obtain the spice commonly known as turmeric, referenced in Ayurvedic medicine, the characteristic medicinal system of Ancient India, as a home remedy for various diseases [4]. The expansion of the therapeutic use of curcumin to the Western civilizations dates from the time of the Portuguese \"State of India\", in the XVI century. [PERSON], the physician of the Viceroy of India, mentioned turmeric in his compendium on Indian plants and principles, as \"a medicine for jaundice\" used widely across Asia [5].  
Turmeric dry rhizome is composed mainly of starch, having also, in lesser extent and in varying composition according to geoclimatic factors, carbohydrates, proteins, lipids, fiber, curcuminoid pigments, sesquiterpenes (turmerone, atlantone, zingiberone, turmeronol, germacrone, \(\alpha\)-curcumene, \(\beta\)-sesquiphellandereine, bisacurone, curcuminone, dehydrocurdione, procurcumadiol, bis-acumol, curcuminols, zedoaronediol, bisabolene, and curlone), and caffeic acid [6; 7]. The curcuminoid content typically varies between 2% and 9%. Curcuminoids are biosynthesized by condensation of malonic acid with cinnacyl CoA or \(p\)-counaroyl CoA. Curcumin is the most abundant curcuminoid inturmeric, but traces of its precursors, desmethoxycurcumin and bisdemethoxycurcumin (Figure 1), are also present [8]. Curcumin and its analogues can be found in several other _Curcuma_ species as well as in a few species from other genera. Sources of curcuminoids include _Curcuma mangga, Curcuma zedaria, Costus speciosus, Curcuma xanthorhiza, Curcuma aromatic, Curcuma phaeocaulis, Etlingera elalitor, and Zingiber cassumunar_[9]. _C. mangga_, commonly named mango ginger, is indicated as a good dietary source of curcumin, but it is still far from reaching the widespread reputation of turmeric as a dietary supplement and functional food.  
In western societies, turmeric consumption is a growing trend due to the recognition of its therapeutic properties against inflammation and cancer [10; 11]. Turmeric has been granted the GRAS status ('Generally Recognized as Safe') by the FDA [12], with an acceptable daily intake (ADI) limit of 2.5 mg/kg of body weight; for pure curcumin, the ADI is of 0.1 mg/kg weight [13]. The official acknowledgement of turmeric as a safe dietary supplement contributed strongly to its widespread use. Turmeric is, since 2013, the top-ranking herbal supplement in North America, having had, in that year, a most impressive sales growth of 26.2% [14]. The applications of curcumin in commercial products are expanding beyond the field of food supplements and tending to grow into other areas, such as cosmetics. While India is the largest producer of curcumin, North America is the largest curcumin market. Market revenue in 2014 was superior to US$20 million [15]. Future market predictions, from now up to 2022, estimate a shift in the demand towards Europe, with Germany and Denmark expected to grow by 17% and to become the largest market. By 2022, the global curcumin market is predicted to reach $94.3 billion [16].