Anti-Inflammatory Effect of Xanthones from Hypericum beanii on Macrophage RAW 264.7 Cells through Reduced NO Production and TNF- α , IL-1 β , IL-6, and COX-2 Expression.

Hypericum beanii N. Robson, a perennial upright herb, predominantly inhabits temperate regions. This species has been utilized for the treatment of various inflammation-related diseases. One new xanthone 3,7-dihydroxy-1,6-dimethoxyxanthone ( 1 ) and twenty-three known xanthones ( 2 - 24 ) were isolated from the aerial parts of H. beanii . The structure of the new compound was determined based on high-resolution electrospray ionization mass spectroscopy (HR-ESIMS), nuclear magnetic resonance (NMR), Infrared Spectroscopy (IR), ultraviolet spectrophotometry (UV) spectroscopic data. The anti-inflammatory effects of all the isolates were assessed by measuring the inhibitory effect on nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages. Compounds 3,4-dihydroxy-2-methoxyxanthone ( 15 ), 1,3,5,6-tetrahydroxyxanthone ( 19 ), and 1,3,6,7-tetrahydroxyxanthone ( 22 ) exhibited significant anti-inflammatory effects at a concentration of 10 μ M with higher potency compared to the positive control quercetin. Furthermore, compounds 15 , 19 , and 22 reduced inducible NO synthase (iNOS), tumor necrosis factor alpha (TNF- α ), interleukin-1 β ( IL-1 β ), IL-6, and cyclooxygenase 2 (COX-2) mRNA expression in the LPS-stimulated RAW 264.7 macrophages, suggesting that these compounds may mitigate the synthesis of the aforementioned molecules at the transcriptional level, provisionally confirming their anti-inflammatory efficacy.