日本、美國、韓國：OMP是安全的

    核心提示：關于牛奶中IGF-1對人體的影響，美國食品藥品局（FDA）早已經做出了結論。2007年5月，在FDA最新公布、經美國國家審計署審計的報告中寫道：“IGF-1與癌癥無關，牛奶中IGF-1濃度的變化不會增加人體罹患癌癥的幾率”。

    事實上，OMP中所包含的是一系列多肽和蛋白類物質，總體來說，這些物質通過促進人體骨中微細血管的生長而促進骨密度的增加，共同對人體骨密度的增強發揮了重要的作用。主要成分為乳鐵蛋白、乳過氧化物酶等。從檢測結果看，特侖蘇OMP牛奶中IGF-1的含量，與普通牛奶相比并無異常。（參見附件：美國明尼蘇達州Hitech Analytical and Diagnostic Solutions實驗室檢測結果）而且從日本、美國、韓國等地的經驗來看，也沒有發現MBP等類似物質致癌的報告。

 

    美國明尼蘇達州Hitech Analytical and Diagnostic Solutions實驗室檢測結果

    Forty-four (44) milk samples from China were analyzed for the presence of IGF-1 level. The results are given in Table 1.

    分析44個來自中國的牛奶樣品中的IGF-1含量，檢驗結果見表1。

    The Analysis was done using ELISA. This assay was developed in house and uses a proprietary protocol. The presence of IGF-1 level was calculated from standard curve. The standard curve was prepared by fitting best curve plotting OD values against IGF-1 concentration/ml. The concentration of standards ranged from 200pg/ml to 3000pg/ml.

   分析使用ELISA方法。建立方法和檢測流程后，從標準曲線中計算出IGF-1的含量。標準曲線的濃度范圍為200 pg/mL～3000 pg/mL

    Ten- (10) additional milk samples from different vendors (CVS, Seven Eleven, Grand Mart, Shoppers, Giant, and Safeway) in the Washington Metropolitan area were also analyzed in the same assay along with Chinese samples. These results are summarized in Table 2.

   另外10個牛奶樣品來源于華盛頓地鐵周邊的銷售商（CVS、Seven Eleven、Grand Mart、Shoppers、Giant 和 Safeway），也用同樣的方法分析，結果匯總于表2。

    The work was performed under GLP conditions following FDA guidelines. The standard curve and performance characteristics of the assay are also provided in the report. The protocol of the ELISA used in this analysis is attached at the end

   整個流程遵循FDA指導的GLP（良好實驗規范）。報告中還提供了標準曲線和性能特點，分析中應用的ELISA方法的流程附在結尾處。

Table 1:  Results of IGF-1 Levels in Milk Samples.

表1：牛奶樣品中IGF-1的含量（樣品來源于中國）

 

Table 2:  IGF-1 Levels in Local Milk Samples.

表2：牛奶樣品中IGF-1的含量（樣品來源于本地）

 

標準曲線

    Linearity Range: 200 pg/mL to 3000 pg/mL   線性范圍：200 pg/mL～3000 pg/mL

    Precision: %CV ranges between 3.6 and 7.8   精密度：3.6% CV～7.8% CV

    Recovery: Recovery of IGF-1 in assay buffer is 112.3%    回收率約為112.3%

 

    Attachment:  附件

    SOP#: EL001                                                     Prepared by: A. Abdullah
    Revision#: 0                                                      Approved by: R. Kango
    Revision Date: N/A                                             Effective Date: January 2, 2009

    This protocol is used for IGF-1 determination in milk samples.

    Materials Used

    1. Elisa Plate coated with a mouse  monoclonal antibody specific to IGF-1
    2. Rabbit polyclonal antibody to human IGF-1
    3. Goat Anti Rabbit IgG conjugated to horseradish peroxidase.
    4. Human IGF-1 Standard: Recombinant Human IGF-1
    5. Assay Buffer: Tris buffer saline containing detergents
    6. Wash Buffer: Tris buffer saline containing detergents
    7. Stop Solution: A 1N solution of HCL in water.
    8. TMB Substrate
    9.  Neutralizing Solution Tris base 200mM with pH 10

    Assay Procedure

    1. Take out number of strip to be used. Place back the remainder of the ELISA plate with desiccant in bag and store at 2-8C.
    2. Bring the reagents and the strips at room temperature.
    3. Prepare the quantity of Assay Buffer to be used by diluting 10X
    4. Prepare  the quantity of Wash Buffer  to be used by diluting 20X
    5. Prepare Standards using Protocol # SP002
    6. Prepare Samples using protocol # SP001
    7. Pipette 100ul of Assay buffer to blank well (NO STANDARDS)
    8. Pipette 100ul of Standard # 1 thru #5 to the appropriate wells.
    9. Pipette 100ul of Samples to appropriate wells.
    10. Seal the plate. Incubate for 2 HOURS on a plate rocker (500rpm) at RT.
    11. Empty wells. Wash by adding 350ul of Wash Buffer to each well. Repeat 5X
    At the end tap the plate on paper towel to remove any remaining buffer.
    12.  Pipette 100ul of polyclonal antibody to each well (EXECPT the BLANK)
    13. Seal plate. Incubate for 2 ? HOURS on a plate rocker (500rpm) at RT.
    14.  Repeat step 11.
    15.  Pipette 100ul of conjugate to each well (EXCEPT BLANK)
    16.  Seal plate. Incubate for 1 HOUR on a plate rocker at RT.
    17.  Repeat step 11.
    18.  Pipette 100ul substrate to each well (INCLUDING BLANK)
    19.  Seal the plate. Incubate for 30 MIN on plate rocker at RT.
    20.  Pipette 100ul of stop solution to each well (INCLUDING BLANK)
    21.  Read Optical Density at 450nm.
    22.  Convert the OD value to IGF-1 content using standard curve. Adjust the values for the dilution of the samples.

    References:

    1. Measurement of Bovine Somatotropin (bST) and Insulin-Like Growth Factor-1 in Bovine Milk Using an Electrocheminescent Assay: Michael F. McGrath et al
    J. Agric Food Chem. 2008, 56, 7044 - 7048.

    2. An Immunoenzymatic Method to Measure IGF-1 in Milk: A. Guidi et al.
    Veterinary Research communication, 31(Suppl. 1) (2007) 373 - 376.

    作為一種成長因子，IGF-1普遍存在于人體血液、牛奶和人的母乳之中，對人體生長發育起著重要的作用。科學研究證明，IGF-1在鮮牛奶中的含量也會隨季節和牛的生理周期的變化出現大幅度波動。關于牛奶中IGF-1對人體的影響，美國食品藥品局（FDA）早已經做出了結論。2007年5月，在FDA最新公布、經美國國家審計署審計的報告中寫道：“IGF-1與癌癥無關，牛奶中IGF-1濃度的變化不會增加人體罹患癌癥的幾率”。（參見附件：FDA關于IGF-1的結論）在我國人均飲奶量為21.7公斤、而世界平均水平已達100公斤，應該說，飲奶平均水平較高的國家，居民的IGF-1攝入量也相對較高，但是，統計資料表明，這些國家并沒有成為癌癥的“重災區”。

 

附件

    FDA結論：IGF-1不是天生有害物質

    核心提示：公開發表一篇論文，即關于前列腺癌與IGF-1的關聯。研究表明， 血漿中的IGF-1含量與前列腺癌的增長風險肯定有聯系。雖然這種作用機理與引發癌癥有關，但沒有完全定義，但很顯然IGF-1不是致癌因素。

    FDA關于IGF-1的結論

    Report on the Food and Drug Administration's Review of the Safety of Recombinant Bovine Somatotropin

    05-03-2007

    IGF-I

    The Canadian report indicates that milk from rbGH-treated cows contains significantly elevated levels of insulin-like growth factor I (IGF-I) in milk, and presents human health safety concerns. IGF-I is a protein normally found in all humans, and is not intrinsically harmful. IGF-I is necessary for normal growth, development, and health maintenance. Circulating plasma血漿 levels of the hormone increase from birth to late puberty and subsequently decline in adults to approximately 100 ng (10-9 grams)/ml (range = 42 - 308 ng/ml for men and women >23 yrs). IGF-1 is structurally similar to insulin and, like insulin, is not biological effective following oral administration.
    IGF－1是所有人體內自然生成的一種蛋白質，不是天生有害物質。對于人類的發育、生長和健康的維護是有必要的。人類從出生到青春后期，血漿里的荷爾蒙含量是呈增加狀的。成年后下降到大概100納克（范圍：42－308納克/毫升 男人和女人大于23歲）。IGF-1從結構上與胰島素類似，是一種類胰島素， 口服之后不會產生生物有效性。

    The safety of IGF-I in milk was thoroughly considered by FDA in its review of the Posilac application. Some early studies suggested that treatment of dairy cows with rbGH produced a slight, but statistically significant, increase in the average milk IGF-I concentration. FDA determined that this modest increase in milk IGF-I concentration was not a human food safety concern because it was less than the natural variation in milk IGF-I levels observed during lactation 哺乳期and was less than the fluctuation observed in milk from treated and control cows prior to rbGH administration.
    FDA認為牛奶中適度增加IGF-1濃度，不會造成食品安全方面的隱患。因為通過人類哺乳期的觀察，增加IGF-1含量的牛奶中IGF-1的變化少于天然牛奶中的IGF-1的變化。波動也小于應用rBGH之前。

    Since making that analysis, however, FDA has received and reviewed several more comprehensive studies designed to ascertain the effect of rbGH treatment on milk IGF-I levels. These studies have demonstrated that the levels of IGF-I found in milk from treated cows are within the range of those normally found in milk from untreated cows. In 1993, the JECFA Committee concluded, "the most definitive and comprehensive studies demonstrate that IGF-I concentrations [in milk] are not altered after rbGH treatment". The 1998 JECFA Committee report summarized a study showing no significant difference in commercially available milk labeled as coming from non-rbGH treated cows and milk from cows presumed to be treated with rbGH but not labeled as to treatment.

    A recent study(6) has been published on the association between prostate cancer and IGF-I. This study showed a positive correlation between the level of IGF-I in plasma and the increased risk of prostate cancer. Although the mechanism responsible for induction of cancer has not been characterized fully, it is clear that IGF-I is not the causative agent.很顯然IGF-1不是致癌因素。
    (1998) Plasma Insulin-like Growth Factor-I and Prostrate Cancer Risk: A Prospective Study. Science, 公開發表一篇論文，即關于前列腺癌與IGF-1的關聯。研究表明， 血漿中的IGF-1含量與前列腺癌的增長風險肯定有聯系。雖然這種作用機理與引發癌癥有關，但沒有完全定義，但很顯然IGF-1不是致癌因素。

    FDA has examined the literature and finds no definitive evidence of any direct link between IGF-I and breast cancer. 與乳腺癌沒有直接聯系。Some authors have hypothesized a link, whereas others have expressed that while IGF-I is one of several growth factors and hormones that can contribute to an increase in cell numbers of many cell types invitro, no one factor is responsible for changing normal cells into cancerous cells. Furthermore, FDA has been advised that there is no substantive evidence that IGF-I causes normal breast cells to become cancerous.(7)沒有足夠的證據證明，IGF-1會導致正常的乳腺細胞癌變。