isorhapontigenin and Inflammation

Nuclear factor erythroid-2 related factor 2 (Nrf2) is involved in mitigating various oxidative stress- and inflammation-induced diseases, including acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Isorhapontigenin (ISO), from the Chinese herb Gnetum cleistostachyum, exhibits antioxidant and anti-inflammatory properties. In this study, we explored the protective effects of ISO in ALI and its underlying molecular mechanisms. ISO significantly mitigated ALI by reducing the lung wet/dry weight ratio, protein concentration in the bronchoalveolar lavage fluid (BALF), and the levels of myeloperoxidase and malondialdehyde. ISO also improved the superoxide dismutase and glutathione activity in vivo. Moreover, ISO effectively ameliorated the changes in IL-1β, IL-6, and TNF-α concentrations in BALF, prevented IκB degradation, and inhibited the phosphorylation of NF-κB p65 subunit in lung tissues; furthermore, it enhanced the nuclear translocation of Nrf2 and inhibited IL-1β, IL-6, TNF-α, iNOS, COX-2, and ROS production in lipopolysaccharide-treated RAW264.7 cells. The protective effects of ISO in ALI were significantly reversed in ML385-treated RAW264.7 cells and the mouse model, indicating its role in Nrf2-activation. In conclusion, ISO effectively ameliorated lipopolysaccharide-induced ALI by reducing inflammation and oxidative stress, primarily through activation of Nrf2 signaling.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Cells, Cultured; Humans; Inflammation; Lipopolysaccharides; Mice; NF-E2-Related Factor 2; Oxidative Stress; Signal Transduction; Stilbenes

Osteoarthritis (OA) is a common cause of joint pain and physical disability in the elderly. It is highly associated with local inflammatory reactions and cartilage degradation. Isorhapontigenin (ISO), a natural compound existing in various plants, has shown prominent anti-inflammatory and anti-oxidative properties in several inflammatory diseases. However, the effects of ISO on OA remain to be elucidated. Here, we investigated the effects of ISO on interleukin-1β (IL-1β)-treated rat chondrocytes and cartilage explants. Our results revealed that ISO could suppress the IL-1β-induced elevated levels of nitric oxide (NO), inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX2). Besides, ISO could also inhibit the IL-1β-induced up-regulation of cartilage matrix catabolic enzymes such as matrix metalloproteinases (MMPs) and aggrecanase-2 (ADAMTS5). Moreover, the IL-1β-induced downregulation of collagen II and aggrecan could be reversed by ISO. Furthermore, ISO prevented rat cartilage explant damage induced by IL-1β. Mechanistically, ISO worked partly by suppressing mitogen-activated protein kinase (MAPK)-associated ERK and p38 pathways. Taken together, our study indicated the anti-inflammatory potential of ISO on IL-1β-treated rat chondrocytes, providing a new idea for OA treatment.

Topics: Animals; Anti-Inflammatory Agents; Cartilage; Chondrocytes; Inflammation; Interleukin-1beta; Matrix Metalloproteinases; Mitogen-Activated Protein Kinases; Osteoarthritis; Rats; Stilbenes

Chronic obstructive pulmonary disease (COPD) is a corticosteroid-resistant airway inflammatory condition. Resveratrol exhibits anti-inflammatory activities in COPD but has weak potency and poor pharmacokinetics. This study aimed to evaluate the potential of isorhapontigenin, another dietary polyphenol, as a novel anti-inflammatory agent for COPD by examining its effects in vitro and pharmacokinetics in vivo.. Primary human airway epithelial cells derived from healthy and COPD subjects, and A549 epithelial cells were incubated with isorhapontigenin or resveratrol and stimulated with IL-1β in the presence or absence of cigarette smoke extract. Effects of isorhapontigenin and resveratrol on the release of IL-6 and chemokine (C-X-C motif) ligand 8 (CXCL8), and the activation of NF-κB, activator protein-1 (AP-1), MAPKs and PI3K/Akt/FoxO3A pathways were determined and compared with those of dexamethasone. The pharmacokinetic profiles of isorhapontigenin, after i.v. or oral administration, were assessed in Sprague-Dawley rats.. Isorhapontigenin, an orally bioavailable dietary polyphenol, displayed superior anti-inflammatory effects compared with resveratrol. Furthermore, it suppressed the PI3K/Akt pathway that is insensitive to corticosteroids. These favourable efficacy and pharmacokinetic properties support its further development as a novel anti-inflammatory agent for COPD.

Topics: Administration, Oral; Adrenal Cortex Hormones; Aged; Animals; Anti-Inflammatory Agents; Biological Availability; Cell Survival; Dose-Response Relationship, Drug; Epithelial Cells; Female; Humans; Inflammation; Injections, Intravenous; Male; Molecular Structure; Pulmonary Disease, Chronic Obstructive; Rats; Rats, Sprague-Dawley; Respiratory System; Resveratrol; Stilbenes; Structure-Activity Relationship; Tumor Cells, Cultured