Chemical Name: 5,6,7,8-tetramethoxy-2-(4-methoxyphenyl)-4H-1-benzopyran-4-one
Melting point: 155-156
Chemical formula: C20H20O7
Tangeritin is one of the Citrus bioflavonoids. Tangeritin may play a role, like many flavonoids, in reducing the risk for certain cancers. Tangeritin has also shown promise in protecting nerve cells.
Tangeritin is a polymethoxylated flavone that is found in tangerine and other citrus peels. Tangeritin is commercially available as a dietary supplement.
Although few randomized, double-blind human studies have been done, animal research shows the potential of tangeritin as a cholesterol lowering agent. A hamster study showed potential protective effects against Parkinson's disease. Tangeritin shows potential as an anti cancer agent. In in vitro studies, tangeritin appears to counteract some of the adaptations of cancer cells. Tangeritin strengthens the cell wall and protects it from invasion. Tangeritin induced apoptosis in leukemia cells while sparing normal cells. It counteracts tumor suppression of gap junction intercellular signaling. It acts to freeze cancer cells in phase G1 of the cell cycle, preventing replication. In summary, in vitro studies show antimutagenic, antiinvasive and antiproliferative effects. One caveat is that tangeritin appears to counteract the anticancer drug tamoxifen and to suppress thee activity of natural killer cells.
Sytrinol has polymethoxylated flavones (PMFs) that decrease apoprotein B, a structural protein needed for endogenous synthesis of LKL cholesterol. PMFs (tangeritin and nobiletin) decrease diacylglycerol acetyl transferase, a liver enzyme needed for endogenous synthesis of triblycerides.
Tangeritin Research Update:
A safety study of oral tangeretin and xanthohumol administration to laboratory mice.
In Vivo. 2005 Jan-Feb;19(1):103-7.
The detection of molecular targets for flavonoids in cell signalling has opened new perspectives for their application in medicine. Both tangeretin, a citrus methoxyflavone, and xanthohumol, the main prenylated chalcone present in hops (Humulus lupulus L.), act on the mitogen-activated protein kinase pathway and await further investigation for administration in vivo. MATERIALS AND METHODS: A safety study was designed in laboratory mice orally administered concentrates of purified tangeretin (1 x 10(-4) M) or xanthohumol (5 x 10(-4) M) at libitum for 4 weeks. Blood samples were collected for the analysis of a variety of haematological and biochemical parameters. RESULTS: A reduction of the circulating lymphocyte number was noticed for tangeretin, while all other parameters were unaffected by treatment with either tangeretin or xanthohumol. The parameters encompassed an integrity check of the following tissues and organs: bone marrow, liver, exocrine pancreas, kidneys, muscles, thyroid, ovaries and surrenal cortex. Furthermore, no differences were noted in the metabolism of proteins, lipids, carbohydrates and uric acid, as well as in ion concentrations. CONCLUSION: All data indicate that oral administration of tangeretin or xanthohumol to laboratory mice does not affect major organ functions and opens the gate for further safety studies in humans.
Tangeretin inhibits extracellular-signal-regulated kinase (ERK) phosphorylation.
FEBS Lett. 2005 Mar 14;579(7):1665-9.
Tangeretin is a methoxyflavone from citrus fruits, which inhibits growth of human mammary cancer cells and cytolysis by natural killer cells. Attempting to unravel the flavonoid's action mechanism, we found that it inhibited extracellular-signal-regulated kinases 1/2 (ERK1/2) phosphorylation in a dose- and time-dependent way. In human T47D mammary cancer cells this inhibition was optimally observed after priming with estradiol. The spectrum of the intracellular signalling kinase inhibition was narrow and comparison of structural congeners showed that inhibition of ERK phosphorylation was not unique for tangeretin. Our data add tangeretin to the list of small kinase inhibitors with a restricted intracellular inhibition profile.
Tissue distribution and neuroprotective effects of citrus flavonoid tangeretin in a rat model of Parkinson's disease.
Neuroreport. 2001 Dec 4;12(17):3871-5.
Neuroprotective effects of a natural antioxidant tangeretin, a citrus flavonoid, were elucidated in the 6-hydroxydopamine (6-OHDA) lesion rat model of Parkinson's disease (PD), after bioavailability studies. Following the chronic oral administration (10 mg/kg/day for 28 days), significant levels of tangeretin were detected in the hypothalamus, striatum and hippocampus (3.88, 2.36 and 2.00 ng/mg, respectively). The levels in the liver and plasma were 0.59 ng/mg and 0.11 ng/ml respectively. Unilateral infusion of the dopaminergic neurotoxin, 6-hydroxydopamine (6-OHDA; 8 microg), onto medial forebrain bundle significantly reduced the number of tyrosine hydroxylase positive (TH+) cells in the substantia nigra and decreased striatal dopamine content in the vehicle treated rats. Sub-chronic treatment of the rats with high doses of tangeretin (20 mg/kg/day for 4 days; p.o.) before 6-OHDA lesioning markedly reduced the loss of both TH+ cells and striatal dopamine content. These studies, for the first time, give evidence that tangeretin crosses the blood-brain barrier. The significant protection of striato-nigral integrity and functionality by tangeretin suggests its potential use as a neuroprotective agent.