Anti-Inflammatory Effects and Mechanisms of Action of Coussaric and Betulinic Acids Isolated from Diospyros kaki in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Abstract

Diospyros kaki Thunb. is widely distributed in East Asian countries, its leaves being mainly used for making tea. In this study, coussaric acid (CA) and betulinic acid (BA), both triterpenoid compounds, were obtained from D. kaki leaf extracts through bioassay-guided isolation. CA and BA showed anti-inflammatory effects via inhibition of the nuclear factor-κB (NF-κB) pathway, providing important information on their anti-inflammatory mechanism. Furthermore, they markedly inhibited nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages, and suppressed tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) levels. Furthermore, they decreased protein expression of inducible nitric oxide synthase and cyclooxygenase-2. Pre-treatment with CA and BA inhibited LPS-induced NF-κB. We further examined the effects of CA and BA on heme oxygenase (HO)-1 expression in RAW 264.7 macrophages: BA induced HO-1 protein expression in a dose-dependent manner, while CA had no effect. We also investigated whether BA treatment induced nuclear translocation of Nrf2. BA inhibited LPS-induced NF-κB-binding activity, as well as pro-inflammatory mediator and cytokine production (e.g., NO, PGE 2 , TNF-α, IL-1β, IL-6), by partial reversal of this effect by SnPP, an inhibitor of HO-1. These findings further elucidate the anti-inflammatory mechanism of CA and BA isolated from D. kaki.

Inhibitory Effects of Betulinic Acid on LPS-Induced Neuroinflammation Involve M2 Microglial Polarization via CaMKKβ-Dependent AMPK Activation

“…This compound has been reported to possess various kinds of biological properties, including anti-inflammatory, anticancer, antimalarial, and antiplatelet activities, etc. ( Lee et al, 2011 ; Wan et al, 2013 ; Jingbo et al, 2015 ; Ju et al, 2015 ; Lingaraju et al, 2015 ; Kim et al, 2016 ; Laavola et al, 2016 ). The anti-inflammatory effect of BA is well recognized in several different models ( Saaby and Nielsen, 2012 ; Wan et al, 2013 ; Ju et al, 2015 ; Lingaraju et al, 2015 ; Kim et al, 2016 ; Laavola et al, 2016 ).…”

Induction of Cell Death by Betulinic Acid through Induction of Apoptosis and Inhibition of Autophagic Flux in Microglia BV-2 Cells

“…Betulinic acid (3-beta-hydroxy-lup-20(29)-ene-28-oic acid, BA) is a natural pentacyclic triterpene that can be isolated from various plants including white birch bark ( Yogeeswari and Sriram, 2005 , Sami et al ., 2006 ). BA has been reported to have a variety of biological and pharmacological activities: tumor suppression ( Periasamy et al ., 2014 ; Zhang et al ., 2016 ), anti-inflammatory effect ( Kim et al ., 2016 ), and anti-parasitic activity ( Meira et al ., 2016 ).…”

Diospyros kaki calyx inhibits immediate-type hypersensitivity via the reduction of mast cell activation

“…Especially, coussaric acid and betulinic acid, both triterpenoid compounds, were obtained from D. kaki leaf extracts through bioassay-guided isolation and showed anti-inflammatory effects via inhibition of the NF-κB pathway, providing important information on their anti-inflammatory mechanism (Kim et al. 2016 ). In our previous study, D. kaki has shown anti-allergic inflammatory effect (Kim et al.…”