Curcumin stability

Regarding the data concerning the stability of curcumin in solution, it is advisable to perform extraction under acidic conditions and to avoid direct light exposure. However, it will also depend on the material from which curcumin has to be extracted. 

Wang, Y.J. et al., Stability of curcumin in buffer solutions and characterization of its degradation products, J. Pharm. Biomed. Anal, 15, 1867, 1997. 

Some metabolites of curcumin (particularly tetrahydrocurcumin) may also participate in producing the observed effects of curcumin in different models because these metabolites display greater stabilities than the parent curcumin molecule at physiological pH. Recent data show similar modes of action of curcumin metabolites regarding antioxidant enzyme induction and inhibition of multidrug-resistant proteins. " Additional data indicate that curcumin may even act against other types of diseases such as atherosclerosis " " and Alzheimer s disease. " - " ... 

Tpnnesen, H.H, Masson, M., and Loftsson, T., Studies on curcumin and curcuminoids. XXVII. Cyclodextrin complexation solubility, chemical an photochemical stability, Int. J. Pharm., 244, 127, 2002. 

The most serious problem with curcumin is instability to light. One recommendation is that curcumin should not be used in products that are exposed to light unless the moisture content is very low. A confectionery product that fits this description is boiled sweets. The heat stability of curcumin is sufficiently good that it can withstand 140°C for 15 min in a boiled sweet mass. 

The other stability problem with curcumin is sulfur dioxide. If the sulfur dioxide level is above 100 ppm then the colour will fade. 

In contrast to c-Jun, phosphorylation of the tumor suppressor p53 by CSN-associated kinases targets the protein for degradation by the Ub system [35]. For p53 stability, modification on Thrl55 is most important as shown by mutational analysis [35] and by using different p53 peptides [31]. Mutation of Thrl55 to Val led to stabilization of the transiently expressed p53 mutant in HeLa as well as in HL60 cells [35]. Inhibitors of CSN-associated kinases such as curcumin [18] caused stabilization of cellular p53 followed by massive cell death [35]. 

Iron(III) complexation by 5-nitrotropolone follows the usual mechanistic pattern, 4 at Fe +, at FeOH +aq. Dinuclear Fe2(OH)2 aq, like FeOH +aq, reacts by an mechanism. Curcumin (232) and its diacetyl derivative form complexes with Fe + whose stabilities approach that of Fe -desferrioxamine, hence their suggested use for treatment of iron overload—a topic which dominates the following section devoted to two specific classes of hydroxyketones, viz hydroxypyranones and hydroxypyridinones. ... 

The main coloured substances in the rhizomes are curcumin (1,7-bis (4-hydroxy-3-methoxy prenyl)-l, 6-heptadiene-3, 5-dione) and two related demethoxy compounds, demethoxy curcumin and fczs-demethoxy curcumin, which belong to the group of diarylheptanoids (see Fig. 6.1). Besides these three forms of curcuminoids, three minor constituents have also been isolated (Srinivasan, 1952) that are supposed to be geometrical isomers of curcumin. One of these is assumed to be a cis-trans geometrical isomer of curcumin based on its UV spectrum, lower m.p. and lower stability when compared with curcumin, which has a trans-trans configuration. Heller (1914) isolated an isomer of curcumin with a diketone structure. 

Tonnesen HH, Karlsen J. Studies on curcumin and curcuminoids. VI. Kinetics of cur-cumin degradation in aqueous solution. Z Lebensm-Unters-Forsch 1985 180 402. Tonnesen HH, Karlsen J, van Henegouwen BG. Studies on curcumin and curcuminoids. VIII. Photochemical stability of curcumin. Z Lebensm-Unters-Forsch 1986 183 116. 

Tonnesen HH. Chemistry, Stability and Analysis of Curcumin—a Naturally Occurring Drug Molecule. Ph.D. Dissertation, University of Oslo, Oslo, NO, 1986. 

Tonnesen HH. Studies on curcumin and curcuminoids. XXVIII. Solubility, chemical and photochemical stability of curcumin in surfactant solution. Pharmazie 2002 57 ... 

Tonnesen HH, Karlsen J. Studies on curcumin and curcuminoids. XL Stabilization of photolabile drugs in serum samples by addition of curcumin. Int J Pharm 1988 41 75. 

Thoma and Klimek (115) also found that the natural food colorant curcumin as well as Fast Yellow, chrysoine, apocarotinol, and, cochineal Red A photostabi-lized solutions of nifedipine and nitrofurazone. They also found that vanillin and methyl gallate could stabilize solutions of dihydroergotamine. These authors also found that furosemide was stabilized by the addition of vanillin, haloperidol by benzyl alcohol, and vanillin and thiothixene by quinosol and vanillin. 

Curcumin (1) and its derivatives increased die stability of furosemide, clonazepam, and nifedipin in serum (108), most conspicuously in the case of nifedipin, half-life of which was increased sixfold. This stabilizing effect can be exploited in the formulation of these light sensitive compounds (109). 

The use of natural pigments for food applications is gaining soil from day to day [95]. Curcumin, betaine, amarathine, anthocyanins and P-carotene are the most common and widely used pigments [95,96], Saffron s coloring properties attributed mainly to water-soluble carotenoids are used for coloring of foods. The stability of these saffron pigments in aqueous... 

We demonstrated that a naturally derived polysaccharide, chitosan, is capable of forming composite nanoparticles with silica. For encapsulated particles, we used silicification and biosilicification to encapsulate curcumin and analyzed the physicochemical properties of curcumin nanoparticles. It proved that encapsulated curcumin nanoparticles enhanced stability toward ultraviolet (UV) irradiation, antioxidation and antitumor activity, enhanced/added function, solubility, bioactivities/ bioavailability, and control release and overcame the immunobarrier. We present an in vitro study that examined the cytotoxicity of amorphous and composite silica nanoparticles to different cell lines. These bioactives include curcumin mdAntrodia cinnamomea. It is hoped that by examining the response of multiple cell lines to silica nanoparticles more basic information regarding the cytotoxicity as well as potential functions of silica in future oncological applications could become available. 

The primary focus of tumteric research today is based on its properties as an amio- idam (Zi) and a.s an anticarcinogen (4,5,6). The antioxidant properties of turmeric are based on the ability of curcumin to form complexes with metals and to form a rcsojiance stabilized free radical. Curcumin, along with the other curcuminoids. 

Curcumin is not water-soluble, but it is soluble in ethanol or in dimethylsulfoxide. The degradation kinetics of curcumin under various pH conditions and the stability of curcumin in physiological matrices have been established. When curcumin was incubated in O. IM phosphate buffer and semm-free medium (pH 7.2 at 37°C), about 90% decomposed within 30min. A series of pH conditions ranging from 3 to 10 were tested, and the results showed that decomposition was pH-dependent and occurred faster at neutral-basic conditions. It is more stable in cell culture medium containing 10% fetal calf seram and in human blood. Less than 20% of curcumin decomposed within Ih, and after incubation for 8h, about 50% of curcumin still remained. Trans-6-(4 -hydroxy-3 -methoxyphenyl)-2,4-dioxo-5-hexenal was predicted to be the major degradation product, and vanillin, feralic acid, and feraloyl methane were identified as minor degradation products. The amount of vanillin increased with incubation time. 

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