Skip to 0 minutes and 9 seconds And the third category is there are substances from our diet may affect carcinogen metabolism. As we all know that we may in we make exposed to lots of carcinogens from all our environment, so, there are carcinogens presence in our body more or less all the time. So, if the substances in our diet can alter the carcinogen metabolism, they can also change the risk of getting cancer. So that the substances in our diet may change the transportation or transport of carcinogens to the target cells. Secondly, there are compounds in our diet may modulate the xenobiotic metabolizing enzymes.
Skip to 1 minute and 14 seconds This is a group of enzymes to metabolize lots of carcinogens in our body and a lot of carcinogens, if they can be metabolized they may be detoxified. But there are lots of chances that the carcinogens maybe even activated by this xenobiotic metabolizing enzymes and the diet component may either increase or inhibits the enzyme activities such as there are lots of nutrients or phytochemicals or the bioactive components can alter the xenobiotic metabolizing enzyme activities to alter the the cancer risk And finally, they are also compounds present in our diet may deactivate or prevent the formation of free radicals.
Skip to 2 minutes and 19 seconds as we all know that free radicals is a risk of lots of diseases and in our diet there are lots of antioxidants present including some nutrients such as beta acting vitamin C, etc. And also phytochemicals. I think that most of you have heard about polyphenols and that they are all good antioxidants to prevent or deactivate the free radicals in our body so that they may decrease that cancer risk. In addition to affect the carcinogen metabolism, the diet components may also affect cancer cell metabolism As we all know that cancer is an overgrowth of cells. So if the compounds can affect cell proliferation or affect cell differentiation, they may be affect the cancer progress.
Skip to 3 minutes and 29 seconds So, for cell proliferation there are two categories are related to cell proliferation including cell cycle and the apoptosis. Cell cycle is cell reproduction cycle. If the components or if the diet compounds can enhance thecell reproduction cycle, then it may enhance the cell proliferation toincrease the cancer risk. On the other hand, if we can decrease this or cause the cell cycle arrest, then the cell proliferation will be inhibited. Examples of enhance cell proliferation or enhanced cell cycle is the high-fat diet to decrease or to cause the cell cycle arrest are some phytochemicals present in our diet. Apoptosis is another point.
Skip to 4 minutes and 42 seconds Apoptosis is one kind of cell death as we all know that under homeostasis, cell growth should be equal to cell death. So if we can enhance the apoptosis or cell death, then the cell number can be decreases. There are lots of components or lots of diet has been associated with increasing apoptosis of cancer cells, such as garlic or cruciferous vegetables. There are lots of compounds found in this kind of a vegetable have been shown that they can enhance cancer cell apoptosis. Besides cell proliferation, lots of cancer cells are undifferentiated cells and that they are under poor differentiation. So if we can enhance cancer cell differentiation, they can correct or they can prevent or even treat the cancer.
Skip to 5 minutes and 52 seconds One of the good example is vitamin A. Vitamin A has been shown that it can increase the cancer cell differentiation so that it can decrease the cancer risks.
Substances affecting metabolism of carcinogens
You may hear about “antioxidant.” It is a molecule that inhibits the oxidation of other molecules. Oxidation is a chemical reaction that can produce free radicals, leading to chain reactions that may damage cells.
Oxidation is one the important chemical reaction during metabolism. In this video, Prof. Chen will explain how these substances affect metabolism of carcinogens.