When hot may be anticarcinogenic.When hot may be anticarcinogenic Four years ago, researchers at the Eppley Institute for Research in Cancer at the University of Nebraska in Omaha showed that capsaicin capsaicin /cap·sa·i·cin/ (kap-sa´i-sin) an alkaloid irritating to the skin and mucous membranes, the active ingredient of capsicum; used as a topical counterirritant and analgesic. cap·sa·i·cin n. , the predominant capsaicinoid, can cause genetic mutation in the Ames test -- a quick bacterial assay used to screen for possible carcinogens. More recently, these and other researchers have found additional evidence suggesting capsaicin might cause colon cancer in animals. But the newest studies by the Eppley team now indicate the pungent chemical may also be an antioxidant, and therefore capable of neutralizing harmful oxygen species in the body. In their work, Peter Gannett and Patrick Iversen found that capsaicin strongly binds to at beast one form of the cytochrome P-450 enzyme -- the "j" form, which is believed to activate certain mutagens including nitrosamines nitrosamines highly hepatotoxic compounds formed in the rumen by the combination of amines and nitrite. They do not appear to occur naturally in large quantities. Nitrosamine poisoning has also been caused by feeding nitrite-treated fishmeal and Solanum incanum. . In the first stage of a two-step process, capsaicin is oxidized oxidized having been modified by the process of oxidation. oxidized cellulose see absorbable cellulose. -- donating an electron to another molecule. Gannett says it appears the P-450j enzyme actually fosters the oxidation by accepting the electron. Then the oxidized capsaicin appears to covalently bind to the P-450j, effectively inactivating it. Dimethylnitrosamine dimethylnitrosamine a potent hepatoxin in herring meal. Chronic poisoning causes changes reminiscent of neoplasia and the substance is now regarded as a carcinogen. (DMN DMN Dimension DMN Dimethylnitrosamine (carcinogen) DMN Data Multiplexing Network DMN Defective Material Notice DMN Discrete Memoryless Network DMN Document Management Number DMN Dynamic Mesh Network DMN Digital Milti-Network ) -- a known animal carcinogen -- is usually a potent mutagen mutagen: see mutation. mutagen Any agent capable of altering a cell's genetic makeup by changing the structure of the hereditary material, DNA. Many forms of electromagnetic radiation (e.g. in the Ames assay. but when the Eppley researchers conducted an Ames assay on paired exposure to both DMN and capsaicin, "we found the mutagenicity mutagenicity /mu·ta·ge·nic·i·ty/ (-je-nis´it-e) the property of being able to induce genetic mutation. mutagenicity the property of being able to induce genetic mutation. of the DMN was effectively destroyed," Gannett says. Work by others, he notes, has found evidence that capsaicin can also bind to a P-450c enzyme -- one believed to activate potentially cancer-causing polycyclic aromatic hydrocarbons (PAHs). The implication, Gannett believes, is that capsaicin may "interfere with nitrosamine- or PAH metabolism" -- preventing their harmful transformation into potent mutagens. So this popular and peppery food constituent may have the dubious distinction of presenting a low-level cancer risk to the gut while at the same time neutralizing enzymes that might otherwise turn on classes of other carinogens. |
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