Troxerutin (TXN) is a flavonoid present in tea, coffee, cereal grains, and a variety of fruits and vegetables. It inhibits the agglomeration of blood platelets and red blood cells; prevents thrombogenesis; protects endothelial cells; and enhances microcirculation. It possess anti-inflammatory and anti-apoptotic properties. Troxerutin protected different cell types (epithelial cells, fibroblasts and lymphocytes) against peroxyl radical-induced apoptosis, necrosis and mitotic death. It scavenged intracellular basal and inducible ROS levels and also restored depletion of intracellular GSH levels. Troxerutin might provide a safe and effective treatment for rhinorrhea in the common cold deserves systematic evaluation. The use of a mixture of troxerutin, diosmin and hesperidin is a safe and effective mean of managing symptoms of acute hemorrhoidal disease. Troxerutin is used for the treatment of chronic venous insufficiency.

Since its first isolation in 1844, usnic acid has become the most extensively studied lichen metabolite and one of the few that are commercially available. Lichens belonging to usnic acid-containing genera have been used as crude drugs throughout the world. There are indications of usnic acid being a potentially interesting candidate for such activities as anti-inflammatory, analgesic, healing, antioxidant, antimicrobial, antiprotozoal, antiviral, larvicidal and UV protection. However, some studies reported the liver toxicity and contact allergy. Usnic acid reduced the production of Junin virus in infected Vero cells in a dependent dose manner, and 50% inhibition was obtained at an effective concentration (EC50) of 9.9 µM. Regarding the TCRV arenavirus, the effective concentration was 20.6 uM. The selectivity indexes (CC50/EC50) of usnic acid for JUNV and TCRV arenavirus were 6.8 and 3.2, respectively, indicating a specific antiviral activity against these viruses and not just a general consequence of its action on cellular toxicity.

Baicalin is a flavonoid compound with anti-inflammatory and anti-oxidant activity extracted from Scutellarua rivularis. Limited distribution data suggest that baicalin reached several sites such as the brain, eye lens, thymus, etc. Metabolism data suggest the rapid conversion of baicalin to baicalein. Baicalin has the potential to be used in novel anti-cancer therapeutic formulations for treatment of ovarian cancer and other cancers. Baicalin markedly inhibits replication of human immunodeficiency virus type 1 (HIV-1) in a concentration-dependent manner in normal peripheral blood mononuclear cells (PBMC) stimulated with phytohemagglutinin (PHA) in vitro. The preventive medication of baicalin shows a protective effect on C57 BL mouse with Parkinson's disease induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP).

Cianidanol is an antioxidant flavonoid, occurring especially in woody plants as both (+)-catechin and (-)-epicatechin (cis) forms. One of the polyphenols present in green tea, (+)-catechin (Cianidanol), has been studied for its effects on animal models of hepatitis, as well as in human clinical studies. Pure (+)-catechin (also known as (+)- cyanidanol-3 – trade name Catergen) has been used to treat hepatitis since 1976. This compound has been shown to be an efficient immune stimulator, promoting activation of macrophages, cytotoxic-T-lymphocytes, and natural killer cells in mice. Several clinical studies demonstrate the effectiveness of (+)-catechin in the treatment of viral hepatitis. Pure (+)-catechin has been found to cause hemolysis in some patients, possibly by the promotion of antibody formation against (+)-catechin, which might cross-react with red blood cells. However, there are no reports in the literature of green tea, green tea extracts, or green tea polyphenols causing this side-effect.