Triterpenoids from Ganoderma lucidum and Their Potential Anti-inflammatory Effects

Area of Science:

• Pharmacology
• Natural Products Chemistry
• Immunology

Background:

• Ganoderma lucidum is widely used in Eastern Asian countries as food, tea, dietary supplement, and medicine.
• Two official species in China, G. lucidum and G. sinense, are often used interchangeably, necessitating clarification on their distinct properties.
• The anti-inflammatory potential of G. lucidum constituents requires further investigation.

Purpose of the Study:

• To isolate and identify anti-inflammatory compounds from the fruiting bodies of G. lucidum.
• To evaluate the anti-inflammatory activity of isolated compounds in macrophage cells.
• To provide references for the distinct usage of G. lucidum and G. sinense.

Main Methods:

• Chemical isolation and structural elucidation of compounds from G. lucidum fruiting bodies.
• In vitro assays using RAW264.7 macrophage cells stimulated with lipopolysaccharide (LPS).
• Measurement of nitric oxide (NO), interleukin-6 (IL-6), and interleukin-1β (IL-1β) production.
• Assessment of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-kappa B (NF-κB) expression.
• Analysis of IκBα and IKKβ phosphorylation.

Main Results:

• Six new triterpenoids (1-6) and 27 known analogues (7-33) were isolated.
• Compound 4 showed the most potent inhibition of nitric oxide production induced by LPS.
• Compound 4 significantly reduced IL-6, IL-1β, iNOS, COX-2, and NF-κB expression in a dose-dependent manner.
• Compound 4 effectively blocked the phosphorylation of IκBα and IKKβ in LPS-stimulated macrophage cells.

Conclusions:

• Compound 4 is a potential anti-inflammatory candidate.
• Total triterpenoids from G. lucidum may be developed as functional foods for inflammation prevention.
• Caution is advised regarding the interchangeable use of G. lucidum and G. sinense based on current and previous studies.