Indole derivatives with therapeutic properties

The bicyclic ring system of indole (benzo[b]pyrrole) is a structural element of many therapeutic agents used in medical practice with diverse biological activities, including anticancer, antibacterial, antiviral, anti-inflammatory, analgesic, antipyretic and hypotensive drugs as well as antidepressants or antipsychotics. Indole compounds, both natural and synthetic, have long been used as anticancer drugs in the treatment of neoplastic diseases such as lung cancer, breast cancer, sarcomas, lymphomas, and tumors of the central nervous system. On the other hand, as antiemetic drugs, they are used in oncological patients undergoing chemotherapy and radiotherapy. Indole compounds regulate the functioning of the endocrine system and are used in the treatment of hyperprolactinemia, endometriosis, and central premature children’s puberty. They are important for the proper functioning of the nervous system and therefore are used in patients suffering from neurodegenerative diseases, such as Parkinson’s or Alzheimer’s disease. The indole ring is also the basis of drugs used, among others, in cardiovascular diseases - in the treatment of arterial hypertension, in the digestive system - in irritable bowel syndrome, in the respiratory system in particular in the case of asthma as well as in bone tissue diseases indicated for the treatment of osteoporosis. Indole derivatives are in the focus of many research centers, in which their new properties are constantly being discovered. It should be emphasized, that aromatic or heteroaromatic rings constituting the structural motif of compounds with different pharmacological effects are referred to as privileged structures. This group of heterocyclic compounds also includes indole. This article is intended to provide a review of currently used drugs containing the heterocyclic indole system in their structures and their possible clinical applications. The current directions of searching for novel indole-based drugs are also presented.