Optimized mixture of hops rho iso-alpha acids-rich extract and acacia proanthocyanidins-rich extract reduces insulin resistance in 3T3-L1 adipocytes and improves glucose and insulin control in db/db mice.

Rho iso-alpha acids-rich extract (RIAA) from Humulus lupulus (hops) and proanthocyanidins-rich extracts (PAC) from Acacia nilotica exert anti-inflammatory and anti-diabetic activity in vitro and in vivo. We hypothesized that a combination of these two extracts would exert enhanced effects in vitro on inflammatory markers and insulin signaling, and on nonfasting glucose and insulin in db/db mice. Over 49 tested combinations, RIAA:PAC at 5:1 (6.25 µg/mL) exhibited the greatest reductions in TNFα-stimulated lipolysis and IL-6 release in 3T3-L1 adipocytes, comparable to 5 µg/mL troglitazone. Pretreatment of 3T3-L1 adipocytes with this combination (5 µg/mL) also led to a 3-fold increase in insulin-stimulated glucose uptake that was comparable to 5 µg/mL pioglitazone or 901 µg/mL aspirin. Finally, db/db mice fed with RIAA:PAC at 5:1 (100 mg/kg) for 7 days resulted in 22% decrease in nonfasting glucose and 19% decrease in insulin that was comparable to 0.5 mg/kg rosiglitazone and better than 100 mg/kg metformin. RIAA:PAC mixture may have the potential to be an alternative when conventional therapy is undesirable or ineffective, and future research exploring its long-term clinical application is warranted.

META060 inhibits osteoclastogenesis and matrix metalloproteinases in vitro and reduces bone and cartilage degradation in a mouse model of rheumatoid arthritis.

OBJECTIVE: The multikinase inhibitor META060 has been shown to inhibit NF-kappaB activation and expression of markers of inflammation. This study was undertaken to investigate the effect of META060 on biomarkers associated with bone and cartilage degradation in vitro and its antiinflammatory efficacy in vivo in both acute and chronic inflammation models. METHODS: Glycogen synthase kinase 3beta (GSK3beta)-dependent beta-catenin phosphorylation was evaluated in RAW 264.7 macrophages to assess kinase inhibition. The inhibition of osteoclastogenesis and tartrate-resistant acid phosphatase (TRAP) activity was evaluated in RANKL-treated RAW 264.7 cells. The inhibition of interleukin-1beta (IL-1beta)-mediated markers of inflammation was analyzed in human rheumatoid arthritis synovial fibroblasts (RASFs). Mice with carrageenan-induced acute inflammation and collagen-induced arthritis (CIA) were used to assess efficacy. RESULTS: META060 inhibited the activity of kinases (spleen tyrosine kinase [Syk], Bruton's tyrosine kinase [Btk], phosphatidylinositol 3-kinase [PI 3-kinase], and GSK3) associated with RA and inhibited beta-catenin phosphorylation. META060 inhibited osteoclastogenesis, as indicated by decreased transformation of RAW 264.7 cells to osteoclasts and reduced TRAP activity, and inhibited IL-1beta-activated prostaglandin E(2), matrix metalloproteinase 3, IL-6, IL-8, and monocyte chemotactic protein 1 in RASFs. In mice with acute inflammation, oral administration of META060 reduced paw swelling similar to the effect of aspirin. In mice with CIA, META060 significantly reduced the arthritis index and decreased bone, joint, and cartilage degradation. Serum IL-6 concentrations in these mice were inhibited in a dose-dependent manner. CONCLUSION: Our findings indicate that META060 reduces swelling in a model of acute inflammation and inhibits bone and cartilage destruction in a model of chronic inflammation. Its efficacy is associated with the inhibition of multiple protein kinases, including Syk, Btk, PI 3-kinase, and GSK3. These results warrant further clinical testing of META060 for its therapeutic potential in the treatment of inflammatory diseases.

Rho iso-alpha acids from hops inhibit the GSK-3/NF-kappaB pathway and reduce inflammatory markers associated with bone and cartilage degradation.

BACKGROUND: Rho iso-alpha acids (RIAA) from hops have been shown to have anti-inflammatory properties. To understand the mechanisms, we evaluated the effect of RIAA in cell signaling pathways and inflammatory markers using various in vitro models. We also investigated their therapeutic effect in mice with collagen-induced arthritis. METHODS: The LPS-stimulated RAW 264.7 macrophages were used to evaluate the effect of RIAA on the NF-kappaB and MAPK signaling pathways; phosphorylation of ERK1/2, p38 and JNK was assessed by western blotting and NF-kappaB binding by electrophoretic mobility shift assays. Effect on the NF-kappaB activity was evaluated by the luciferase reporter assays in LPS-stimulated RAW 264.7 cells. GSK-3alpha/beta kinase activity was measured in cell-free assays. The inhibitory effect of RIAA on inflammatory markers was assessed by measuring nitric oxide in LPS-stimulated RAW 264.7 cells, RANKL-mediated TRAP activity in transformed osteoclasts, and TNF-alpha/IL-1beta-mediated MMP-13 expression in SW1353 cells. Mice with collagen-induced arthritis were fed with RIAA for 2 weeks. Symptoms of joint swelling, arthritic index and joint damage were assessed. RESULTS: RIAA selectively inhibited the NF-kappaB pathway while having no effect on ERK1/2, p38 and JNK phosphorylation in LPS-stimulated RAW 264.7 cells. RIAA also inhibited GSK-3alpha/beta kinase activity and GSK-3beta dependent phosphorylation of beta-catenin in RAW 264.7 cells. In addition, RIAA inhibited NF-kappaB-mediated inflammatory markers in various cell models, including nitric oxide in LPS-stimulated RAW 264.7 cells, RANKL-mediated TRAP activity in transformed osteoclasts, and TNF-alpha/IL-1beta-mediated MMP-13 expression in SW1353 human chondrosarcoma cells. Finally, in a mouse model of collagen-induced arthritis, RIAA ameliorated joint damage as evidenced by significant reduction of the arthritis index and histology score; at 250 mg/kg-body weight, RIAA had efficacy similar to that of 20 mg/kg-body weight of celecoxib. CONCLUSION: RIAA may have potential as an anti-inflammatory therapeutic.