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 µM, respectively).¹ HMF (50, 100, and 200 µg/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 µM, respectively).³ HMF (50 mg/kg) prevents corticosterone-induced increases in immobility time in the forced swim test in mice.⁴