The invention relates to the field of natural products, and relates to application of
limonin compounds or medicinal derivatives thereof in preparation of medicines for preventing or treating
inflammation. The inventor of the invention finds for the first time that the compound I or the compound II extracted and separated from the
mallotus oblongifolius can significantly inhibit the content of
inflammatory factors of immune cells at an extremely low concentration, and can be used for preparing medicines for preventing or treating
inflammation. Besides, the compound I or II can significantly reduce the expression level of LPS-induced
inflammatory factors TNF-alpha, IL-1alpha, IL-1beta, IL-6 and IL-18 at a low concentration, and does not affect the survival of immune cells, which proves that the compound I or II can inhibit the expression of
inflammatory factors and has a strong anti-inflammatory effect.