Anti-neuroinflammatory polyoxygenated lanostanoids from Chaga mushroom Inonotus obliquus

Chaga mushroom, Inonotus obliquus, was used as food and nutrient food and traditional herbs in Russia, China and Japan, with anti-inflammatory and anticancer activities. Chemical investigations of the fruiting bodies of Chaga were carried to uncover the bioactive metabolites. As a result, seven undescribed lanostane-type triterpenoids, namely inonotusols H-N, were isolated, and all lanostanoids remarkably inhibited NO production in lipopolysaccharide-stimulated BV-2 microglial cells. Of these, inonotusols I and L presented the most potent inhibitory effects on inducible nitric oxide synthase (iNOS) and NO production without any significant cytotoxicity. Molecular docking studies confirmed the capacity of inonotusols I and L to interact with iNOS protein. Structure-activity relationships were also discussed. These results indicated that the potential anti-inflammatory effects of inonotusols I and L in microglial BV-2 cells may be imparted through suppression of iNOS. These results may support the use of I. obliquus for food and medicinal application.

Automated summary

Chaga mushroom, known as Inonotus obliquus, has been used as a food and traditional herb in Russia, China, and Japan, showing anti-inflammatory and anticancer activities. Chemical investigations revealed that Inonotusols I and L, two lanostane-type triterpenoids isolated from Chaga, exhibited potent inhibitory effects on nitric oxide (NO) production without significant cytotoxicity. Molecular docking studies confirmed their interaction with inducible nitric oxide synthase (iNOS) protein, indicating their potential anti-inflammatory effects in BV-2 microglial cells. These findings support the potential use of Inonotus obliquus for food and medicinal purposes.