3,​5,​6,​7,​8,​3',​4'-​Heptemthoxyflavone 

3,5,6,7,8,3',4'-Heptamethoxyflavone (HMF) is a polymethoxyflavone that has been found in C. reticulata and has diverse biological activities.^1,2,3,4 It inhibits the efflux of Hoechst 33342 by breast cancer resistance protein (BCRP) and rhodamine 123 by P-glycoprotein (P-gp), also known as multidrug resistance protein 1 (MDR1), in MDCK cells expressing the human transporters (IC₅₀s = 1.4 and 31 ?M, respectively).¹ HMF (50, 100, and 200 ?g/ml) prevents UVB-induced decreases in type I procollagen in primary human dermal fibroblast neonatal (HDFn) cells.² It inhibits the proliferation of B16 melanoma 4A5, CCRF-HSB-2 leukemia, and TGBC11TKB gastric cancer cells (IC₅₀s = 38, 29, and 9 ?M, respectively).³ HMF (50 mg/kg) prevents corticosterone-induced increases in immobility time in the forced swim test in mice.⁴

1.Pick, A., Müller, H., Mayer, R., et al.Structure-activity relationships of flavonoids as inhibitors of breast cancer resistance protein (BCRP)Bioorg. Med. Chem.19(6)2090-2102(2011) 2.Kim, H.-I., Jeong, Y.-U., Kim, J.-H., et al.3,5,6,7,8,3',4'-heptamethoxyflavone, a Citrus flavonoid, inhibits collagenase activity and induces type I procollagen synthesis in HDFn cellsInt. J. Mol. Sci.19(2)620(2018) 3.Kawaii, S., Tomono, Y., Katase, E., et al.Antiproliferative activity of flavonoids on several cancer cell linesBiosci. Biotechnol. Biochem.63(5)896-899(1999) 4.Sawamoto, A., Okuyama, S., Yamamoto, K., et al.3,5,6,7,8,3',4'-heptamethoxyflavone, a citrus flavonoid, ameliorates corticosterone-Induced depression-like behavior and restores brain-derived neurotrophic factor expression, neurogenesis, and neuroplasticity in the hippocampusMolecules21(4)541(2016)