Norharman or beta-carboline (9H-pyrido[3,4-b]indole) is a neuroactive alkaloid first isolated from Peganum harmala L. It is implicated in a number of human diseases including Parkinson's disease, tremor, addiction and cancer. Norharman formed endogenously but external sources have been identified (among others fried meat and fish, meat extracts, alcoholic drinks, coffee brews, tobacco smoke). It inhibits monoamine oxidase and indoleamine 2,3-dioxygenase. In addition norharman binds with high affinity to imidazoline I2B receptors. Plasma norharman levels are elevated in chronic alcoholics and Parkinson's disease patients.

Alpha-carotene is a provitamin A carotenoid present in fruits and vegetables. Higher serum concentrations of α-carotene have been associated with lower risk of cancer and all-cause mortality. It was suggested that genetic variants influence serum concentrations of provitamin A. Recently was found, that α-carotene effectively inhibits Lewis lung carcinoma (LLC) metastasis and suppresses lung metastasis in combination with taxol in LLC-bearing mice, suggesting that Alpha-carotene could be used as an anti-metastatic agent or as an adjuvant for anti-cancer drugs.

Beta-carotene is found in many foods and is sold as a dietary supplement. Beta-carotene is a carotenoid, weak antioxidant; precursor of vitamin A, which is essential for vision and growth. Used to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (EPP). Has been used in high-dose antioxidant supplements containing ascorbic acid and vitamin E with zinc in high-risk patients with age-related macular degeneration. Beta-carotene is also used to decrease asthma symptoms caused by exercise; to prevent certain cancers, heart disease, cataracts; and to treat AIDS, alcoholism, Alzheimer’s disease, depression, epilepsy, headache, heartburn, high blood pressure, infertility, Parkinson’s disease, rheumatoid arthritis, schizophrenia, and skin disorders including psoriasis and vitiligo.

Propiolactone (or beta-propiolactone) is a disinfectant used in vapor form to sterilize vaccines, grafts, blood plasma, surgical instruments. It has been used against bacteria, fungi, and virus. Propiolactone was first commercially available in the United States in 1958 but then was withdrawn because it was discovered that compound was a human carcinogen. The results have shown the generation of tumors in several tissues and from different administration routes. Propiolactone is a direct-acting alkylating agent that reacts with polynucleotides and DNA, mainly at N7 of guanine and N1 of adenine, to form carboxyethyl derivatives.

Beta-sitosterol is one of the main dietary phytosterols found in plants which have a similar skeleton as cholesterol. In human clinical trials, beta-sitosterol has been shown to have cholesterol-lowering effects and to relieve symptoms of benign prostatic hyperplasia. There has been a large amount of basic research conducted for potential applications of beta-sitosterol in a diverse range of conditions including cervical cancer, breast cancer, cystic fibrosis, and others. Beta-sitosterol is available over the counter as a natural health supplement and is marketed for a wide range of applications including headaches, tuberculosis, allergies, cancers, fibromyalgia, lupus, asthma, hair loss and many others.