In Vitro Anti-Inflammatory Effects of Symplocos sumuntia Buch.-Ham. Ex D. Don Extract via Blockage of the NF-κB/JNK Signaling Pathways in LPS-Activated Microglial Cells

Chemical constituents from symplocos sumuntia and their anti-inflammatory effect

Symplocos sumuntia Buch-Ham ex D Don is traditionally used to relieve inflammation in Vietnam. This study described a chemical investigation that led to isolation and identification of one new and nine known compounds. Their structures were determined by using spectroscopic techniques. Compounds 1 - 10 possessed inhibitory activities on NO production induced by LPS activated macrophages. Among them, compounds 2 and 3 demonstrated strong ability to reduce NO production with IC50 values of 3.91 ± 0.05 and 3.96 ± 0.24 µM, respectively. Some of the other compounds also reduced NO production in LPS stimulated RAW264.7 cells. In-silico study supported hints to the bioactivity of compounds 2 and 3 by analysing the interactions of those when they were docked with protein to create complexes targeting anti-inflammation. Our research revealed the chemical components of this plant and its active ingredients that target inflammation, highlighting its therapeutic potential to improve its value for traditional uses.

Anti-inflammatory Effect of Symplocos prunifolia Extract in an In Vitro Model of Acute Pneumonia

Acute pneumonia is a respiratory disease characterized by inflammation within the lung tissue, exhibiting higher morbidity rates and mortality rates among immunocompromised children and older adults. Symplocos species have been traditionally used as herbal remedies for conditions like dysentery, skin ulcers, diarrhea, and dyspepsia. Contemporary research has employed various Symplocos species in the study of diverse diseases. However, the exact efficacy and mechanisms of action of Symplocos Prunifolia remain unknown. Therefore, this study investigated the anti-inflammatory mechanism of S. prunifolia extract (SPE) in A549 and RAW264.7 cells stimulated by lipopolysaccharide (LPS). SPE significantly reduced nitric oxide (NO) production and the protein expression levels of like inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 cells. Furthermore, it reduced the protein expression levels of iNOS, COX-2 and the levels of pro-inflammatory cytokines in LPS-stimulated A549 cells. The mechanism underlying the anti-inflammatory effect of SPE was associated with the inhibition of LPS stimulated the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) and Mitogen-activated protein kinase (MAPK) phosphorylation. Moreover, we confirmed that SPE decreased the nuclear translocation of nuclear factor-κB (NF-κB)/p65 stimulated by LPS. In conclusion, these results demonstrate that SPE alleviates inflammatory responses by deactivating the PI3K/Akt, MAPK, and NF-κB signaling pathways. Our findings suggest that SPE is a potential candidate for acute pneumonia prevention.

6-Pentyl-α-Pyrone from Trichoderma gamsii Exert Antioxidant and Anti-Inflammatory Properties in Lipopolysaccharide-Stimulated Mouse Macrophages

Filamentous fungi produce several beneficial secondary metabolites, including bioactive compounds, food additives, and biofuels. Trichoderma, which is a teleomorphic Hypocrea that falls under the taxonomic groups Ascomycota and Dikarya, is an extensively studied fungal genus. In an ongoing study that seeks to discover bioactive natural products, we investigated potential bioactive metabolites from the methanolic extract of cultured Trichoderma gamsii. Using liquid chromatography-mass spectrometry (LC-MS), one major compound was isolated and structurally identified as 6-pentyl-α-pyrone (6PP) based on nuclear magnetic resonance data and LC-MS analysis. To determine its antioxidant and anti-inflammatory activity, as well as the underlying mechanisms, we treated lipopolysaccharide (LPS)-stimulated Raw264.7 mouse macrophages with 6PP. We found that 6PP suppresses LPS-induced increase in the levels of nitric oxide, a mediator of oxidative stress and inflammation, and restores LPS-mediated depletion of total glutathione by stabilizing nuclear factor erythroid 2-related factor 2 (Nrf2), an antioxidative factor, and elevating heme oxygenase-1 levels. Furthermore, 6PP inhibited LPS-induced production of proinflammatory cytokines, which are, at least in part, regulated by heme oxygenase-1 (HO-1). 6PP suppressed proinflammatory responses by inhibiting the nuclear localization of nuclear factor kappa B (NF-κB), as well as by dephosphorylating the mitogen-activated protein kinases (MAPKs). These results indicate that 6PP can protect macrophages against oxidative stress and LPS-induced excessive inflammatory responses by activating the Nrf2/HO-1 pathway while inhibiting the proinflammatory, NF-κB, and MAPK pathways.