What Is the Connection Between Curcumin and Cancer?

Curcumin is a chemical component extracted from the rhizomes of some plants in the ginger family and Araceae. Among them, turmeric contains about 3% to 6%, and it is a rare diketone pigment in the plant world. Compounds. Curcumin is an orange-yellow crystalline powder, which has a slightly bitter taste and is insoluble in water. It is mainly used for the coloring of intestinal products, canned food, sauce products and other products in food production. Medical research shows that curcumin has the effects of lowering blood lipids, anti-tumor, anti-inflammatory, choleretic and anti-oxidant. Scientists have discovered that curcumin can help treat drug-resistant tuberculosis. ^[1]

Curcumin was first obtained from 1870

The main source of curcumin is ginger plant

1. Conventional method

The ethanol solution of the chromogenic reaction A sample should be pure yellow and have light green fluorescence; if this ethanol extract is added to concentrated sulfuric acid, a dark purple red will be produced. Color development reaction B Treat the sample with an aqueous solution or a dilute ethanol solution with hydrochloric acid until it starts to become slightly orange.

Divide this mixture into two parts, and add a small amount of boric acid powder or crystals in one part. Compared with the part without boric acid, its color becomes significantly red. Alternatively, several pieces of filter paper can be dipped in an ethanol solution of the pigment, dried at 100 ° C, and then moistened with a dilute solution of boric acid (with a few drops of hydrochloric acid). It should be cherry red after drying.

2.Chromatography

Take 5 ml of the test solution (0.01 g of sample dissolved in 1 mL of 95% ethanol) and drop it on thin layer chromatography (microcrystalline cellulose, 0.1 mm), and place it in 3-methyl-1-butanol / ethanol / water / In the expansion tank of the ammonia (4: 4: 2: 1) mixed liquid, the solvent front was raised by 10 to 15 cm. After one day and night observation under ultraviolet light, there are three yellow spots with Rf between 0.2 and 0.4; the other spots have Rf between 0.6 and 0.8; all spots show yellow fluorescence under ultraviolet light. 6.95% ethanol has the maximum absorption peak at 425 nm.

There are various methods for extracting curcumin, each with its own characteristics in the technological process, but in general, it is divided into two major steps, extraction and purification. In recent years, many new technologies and processes have been used in the extraction and purification of curcumin. The curcumin in turmeric was extracted by enzymatic method. Compared with the traditional extraction process, the yield was increased by 8.1%. The extraction process conditions were: enzymolysis temperature 50 ° C, pH 4.5, time 120 min, and enzyme concentration 0.35 mg / ml. The HPLC method was used as the measurement method, and the curcumin extraction amount was used as the investigation index.

It has been found in practical applications that curcumin still has certain shortcomings, such as low solubility, poor stability, low absorption rate, easy conversion in the intestine to complexes such as glucuronic acid and sulfonic acid, fast metabolism, and short half-life. The existence of Glycidium causes its low bioavailability, which limits its application in the field of food and medicine. As found in human experiments, it can only be detected when the oral dose reaches 10-12 g. Rats are injected intravenously with a curcumin dose of 10 mg / kg, and the maximum concentration in serum is only 0.36 g / mL; 1.0 g / After 15 min of curcumin, the concentration in rat plasma was only 0.13 g / mL, and the maximum concentration was 0.22 g / mL after 1 h. It was not detected in plasma after 6 h. Curcumin was orally administered to rats. Only a small amount was detected in the blood, liver and kidneys. 90% was found in the stomach and small intestine, and only 1% remained after 24 hours. After intraperitoneal injection of 0.1 g / kg curcumin for 1 hour, turmeric was detected. The distribution of vegetative organs varies widely, most in the intestine (117 g / g), second in the kidney, blood and liver, and low in the brain (0.4 g / g). Therefore, improving the bioavailability of curcumin will be an important direction worthy of research in the future.

The main ways to improve curcumin bioavailability are:

(1) Used in conjunction with appropriate medicinal excipients

If curcumin is combined with piperine, an inhibitor of glucuronic acid binding in the liver and intestines, curcumin can also be made into chelate with metal ions, such as copper curcumin to improve its ability to clear active oxygen groups. And pharmacological activity, and reduce metal ion toxicity.

(2) Synthetic curcumin analogs

The biological activity of curcumin depends to a large extent on its chemical structure. Modification of its benzene ring, methylene group and carbonyl group. Screening of derivatives and analogs is an important way to improve its bioavailability.

(3) Change the product dosage form

Curcumin's main product formulations currently include solid dispersions, nanoparticles, liposomes, micelles, etc. For example, using polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) as the carrier to prepare a curcumin solid dispersion, the curcumin-PVP solid dispersion has improved bioavailability in rats compared with ordinary tablets. 590%.

Nanocurcumin has the advantages of long circulation time, strong permeability, and resistance to metabolism in the body, but it has leakage problems. There are a large number of gaps between the hydrogel magnetic nano-mixtures (HGMNC), and the curcumin molecules can be connected to the surface of the nano-particles, so that the release ability is continuous and efficient. Utilizing HGMNC's sensitivity to external magnetic field stimulation, curcumin can be carried to target sites such as cancer cells to play a role in targeted treatment of diseases. Liposomes can fuse with cell membranes, which can send curcumin to the inside of cells, so that drugs are mainly distributed in tissues such as liver, spleen, lung and bone marrow. However, liposomes, as carriers, have problems such as poor stability and easy leakage.

In addition, using NOSC to prepare curcumin micelles can increase drug solubility and improve bioavailability.