In Vitro Immunomodulatory Effects of Inonotus obliquus Extracts on Resting M0 Macrophages and LPS-Induced M1 Macrophages

Abstract

Background. Inonotus obliquus (Chaga) is a parasitic fungus that is distributed mainly in northeast China. Our literature research showed chaga polysaccharides have bilateral effects on tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels when they exert antitumor and antidiabetic activities. The current research tried to explore the influence of chaga extracts on inflammatory factors via macrophage polarization which has bilateral immune-regulation not only on healthy tissue homeostasis but also on pathologies. Methods. Chaga was extracted with 100°C water and precipitated with 80% ethanol. The extracts were studied on RAW264.7 macrophage at resting condition (M0) and lipopolysaccharide (LPS)-activated subtype (classic activated macrophage, M1). The IL-1β, TNF-α, nitric oxide (NO) level, and the protein expressions of M1 and alternative activated macrophage (M2) markers including IL-1β, inducible NO synthase (iNOS), mannose receptor (CD206), and arginase (Arg)-1 were compared. Results. The 100 g extracts contained 13.7 g polysaccharides and 1.9 g polyphenols. Compared with M0, the 50 μg/mL extracts increased NO level ( P < 0.05 ) and decreased CD206 and Arg-1 expression significantly ( P < 0.05 ). The extracts at 100–200 μg/mL increased NO and TNF-α level ( P < 0.05 ), but increased iNOS and IL-1β expression significantly ( P < 0.05 ). Compared with M1, the extracts decreased NO level at 25, 50, 100, and 200 μg/mL and decreased IL-1β and TNF-α level at 100–200 μg/mL significantly ( P < 0.05 ). At 25–200 μg/mL, the extracts significantly increased CD206 and Arg-1 expression and decreased IL-1β and iNOS expression separately ( P < 0.05 ). Conclusions. Our research suggested that the bilateral effects of the chaga extracts on iNOS, IL-1β, and NO level on M0/M1 macrophages might be related with chaga polysaccharides and chaga polyphenols. Some in vivo anticancer and antidiabetic research of purified chaga polysaccharides related to macrophage differentiation should be conducted further.

Synergistic Cytotoxicity of Extracts of Chaga Mushroom and Microalgae against Mammalian Cancer Cells In Vitro

“…Several studies on I. obliquus extracts for their antiinflammatory and anticancer properties have highlighted gallic acid, protocatechuic acid, caffeic acid, syringic acid, betulinic acid, syringic acid, and various triterpenoids including inotodiol and lanosterol as the main bioactive metabolites [37][38][39]. UPLC-ESI-MS characterization of the extracts showed a strong presence of betulinic acid and trametenolic acid, a moderate amount of phenolic acids such as ferulic acid, cinnamic acid, and syringic acid, and a low amount of cinnamic acid, sinapic acid, catechin, and quercetin.…”