Limonoids

Limonoids are phytochemicals, derive from several plant sources. They are found in the peel, pulp and juice of all citrus fruits. Citrus fruits contain the limonoids limonin, nomilin and nomilinic acid, while both neem seeds and leaves contain the limonoid azadirachtin, although higher concentrations are present in the former.
See also : Lemon

Benefits and uses of Limonoids are

• Cancer : limonoids have shown cytotoxicity to breast cancer, colon cancer, pancreatic cancer, liver cancer, neuroblastoma, leukemia, melanoma and non-small cell lung cancer.
• Cholesterol : The American Heart Association reports that over 1 million Americans suffer from high cholesterol, making it a critical problem in the United States as it contributes to your risk of heart attack, stroke and heart disease. Texas A&M published a study in August 2004 that looked at citrus limonoids and their effect on cholesterol in hamsters; the study indicates the these limonoids decreased cholesterol and decreased the risk of oxidation, and therefore might help prevent atherosclerosis. Human studies are needed to confirm these findings.
• Weight Loss : After discovering that limonoids stopped insects from feeding, researchers looked at whether these substances might find use as a therapy for human obesity. While the limonoid studied does not derive from citrus, obese mice experienced reduced energy intake during the study, and the substance also blocks the formation of fat. Citrus limonoids have also been shown as effective against insects; more studies are needed to determine if citrus limonoids have the same effect in animal models as well as in human research.
• Mosquito Killer : Many people use citronella candles and citronella plants to keep mosquitoes away, but citrus limonoids may also offer a solution for repelling stinging and biting pests. A study published in the March 1997 issue of "Phytochemistry" notes that citrus limonoids inhibit adult mosquitoes from emerging from the larva, effectively killing the mosquitoes. This keeps the population of mosquitoes down, reduces your need for natural or chemical bug repellents and may reduce your risk of contracting diseases spread by mosquitoes.