Bibliogr. s. 34-39

Cyclooxygenase is an enzyme involved in many physiological and pathological processes. It catalyzes the formation of prostaglandins, prostacyclins and thromboxanes from arachidonic acid. It has been reported that cyclooxygenase-2 (COX-2) modulates the secretion of proinflammatory mediators and its expression is associated with the promotion of the process of tumorigenesis initiation, transformation, progression and cancer metastasis. Increased expression of COX-2 in premalignant lesions makes it a key element in a chain of changes leading to cancer. So far, advances in the evaluation of COX-2 molecular mechanisms did not bring spectacular discoveries. Pathomechanisms of COX-2 activities are still not sufficiently understood and therefore, require further research. Currently, COX-2 inhibitors are one of the most commonly used medications. Unfortunately, their long-term use causes many side effects. The first report about the use of plant substances with anti-inflammatory and analgesic activity (COX-2 inhibitors) was reported by Hippocrates in the 5th century BC. The present review discusses the most important mechanisms by which a particular COX-2 isomer leads to the formation and development of cancer.