What is Modified Citrus Pectin,MCP,an inhibitor of cancer metastasis and its wide uses?

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Chemistry of MCP(Modified Citrus Pectin).

Modified Citrus Pectin MCP photo picture image Modified citrus pectin powder is produced from citrus pectin via pH and temperature modification that breaks it into shorter, non-branched, galactose-rich, carbohydrate chains. These shorter chains dissolve more readily in water and are better absorbed and utilized by the body than ordinary, long-chain pectins. It is believed the shorter polysaccharide units afford MCP its ability to access and bind tightly to galactose-binding lectins (galectins) on the surface of certain types of cancer cells.

 Natural Source and Origin,Citrus fruit fiber contains pectin:

 a starchy material made up of chains of 'sugar' molecules such as galactose. Citrus pectin molecules are too large to be absorbed through the walls of the digestive tract into the body. Modified Citrus Pectin (MCP) is citrus pectin that has been turned into smaller molecules that dissolve and are absorbed well.

 MCP is currently being investigated as an inhibitor of cancer metastasis (the formation of new tumors by migrating cancer cells). The theory is that MCP prevents migrating cells from adhering to cell surfaces at potential metastatic target sites thus preventing new tumors from forming there.

 The theory is being borne out experimentally. For example, in one experiment 32 rats were implanted with human prostate cancer cells; 16 of these rats were then given a water supply containing 1% MCP. The number of metastatic tumors in the MCP group was dramatically less than that in the control group.

 Modified citrus pectin (MCP) increases the prostate-specific antigen doubling time in men with prostate cancer: a phase II pilot study.

 This trial investigated the tolerability and effect of modified citrus pectin (Pecta-Sol) in 13 men with prostate cancer and biochemical prostate-specific antigen (PSA) failure after localized treatment, that is, radical prostatectomy, radiation, or cryosurgery. A total of 13 men were evaluated for tolerability and 10 for efficacy. Changes in the prostate-specific antigen doubling time (PSADT) of the 10 men were the primary end point in the study. We found that the PSADT increased (P-value less than 0.05) in seven (70%) of 10 men after taking MCP for 12 months compared to before taking MCP. This study suggests that MCP may lengthen the PSADT in men with recurrent prostate cancer.

 Pectin is used in the food industry as a thickening agent and in the production of jams and jellies.While ordinary citrus pectin is beneficial in human nutrition and food industries, a new form called modified citrus pectin (MCP) has been shown to prevent spontaneous prostate cancer metastasis by inhibiting the cancer cells from adhering to other cells in the body. This study with MCP, a special pH-altered form of citrus pectin, was conducted by the researchers at the School of Medicine, University of Michigan, Ann Arbor. Several studies have also shown pectin to have positive influences in decreasing serum cholesterol levels, without effecting serum triglyceride levels. Pectin also has the ability to reduce the rise of blood sugar when combined with meal.

 Commercial pectins are derived mostly from the peel of lemon and lime, orange and grapefruit, however, are used to a lesser extent. The degree of methylation, molecular weight and pH have a major impact on pectin which in turn plays a potential role on human health. Methylation influences the number of receptor binding sites that inhibit the spread of roaming tumor cells. It is critical to have a maximum number of available binding sites on the pectin molecule. It is believed that the higher the percentage of methylation, the fewer receptor binding sites. Currently, commercial pectins have 50-70% methylation. In several companies, however, MCP have low methylation percentages between 5-10%. Another factor important in health benefits of pectin is molecular weight. Commercial pectins have molecular weights ranging from 50,000 to 150,000 daltons.To be absorbed by the digestive tract through the blood stream pectin needs to have a molecular weight between 8,000-10,000 daltons.D-galacturonic acid is the principal constituent of the pectin molecule, but some neutral sugars are also commonly present in pectin. The final factor in pectin and potential health benefits is its pH.Commercial pectins typically have a pH of 3.2 which tends to be acidic to be useful.The MCP produced by several companies, however, have more neutral pH of 5.7-6.3.The potential health role of MCP depends on the appropriate methylation, molecular weight and pH. Pectin levels published and cited for some fruits needs to be reconsidered since there are conflicting values reported from several authors.Membranes which constitute 28% of the edible portion of grapefruit has approximately 4% pectin. If consumed with juice vesicles, the membranes could add another 1% pectin.For example, for a significant serum cholesterol reduction, we need approximately 6 grams pectin per day. Although consumption of peeled citrus fruits greatly increases pectin intake since juice vesicles and carpellary membranes are included.Pectin levels in conventionally cut grapefruit sections are somewhat lower than those of peeled grapefruit because of the carpellary membranes have been excluded by the cutting process.Moreover, newer technologies for peeling and sectioning grapefruit yield whole segments, with carpellary membranes largely intact.As a result, dietary pectin contributed by these intact segments would be presumably similar to that of peeled oranges.

 The most effective sources of citrus pectin and dietary fiber are peel (albedo), membranes, and juice vesicles. Peel and membranes are unsuitable for consumption due to excessive levels of bitter compounds such as naringin and limonin.Juice vesicles, however, are relatively palatable and currently incorporated at low levels in many citrus juices and beverages to provide a more natural fruit juice appearance. To satisfy the need of 6 grams of pectin per day, about 125 grams of juice vesicles would be required if we consider an average of 4.8% pectin in grapefruit on a wet-weight basis.

 Although commercial pectin has a potential role in the food industry, it has a greater role on potential human health based on its processing conditions.

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last edit date:22th,June.2009.