Hyperuricemia is a clinical condition characterized by an elevated level of serum uric acid and is a key risk factor for the development of gout and metabolic disorders. The existing urate-lowering therapies are often impractical for certain patient populations, providing a rationale to explore new agents with improved safety and efficacy. Here, we discovered that Salvia plebeia extract inhibited the enzyme activity of xanthine oxidase, which is a key enzyme generating uric acid in the liver. In an animal model of hyperuricemia, S. plebeia extract reduced serum urate to the levels observed in control animals. The urate-lowering effect of S. plebeia extract in vivo was supported by the identification of compounds that inhibit xanthine oxidase enzyme activity in vitro. Nepetin, scutellarein, and luteolin contributed significantly to S. plebeia bioactivity in vitro. These compounds showed the highest potency against xanthine oxidase with IC₅₀ values of 2.35, 1.74, and 1.90 µM, respectively, and were present at moderate quantities. These observations serve as a basis for further elaboration of the S. plebeia extracts for the development of new therapeutics for hyperuricemia and related diseases. ^* These authors contributed equally to this work.

The activation of NLRP3 results in the assembly of inflammasome that regulates caspase-1 activation and the subsequent secretion of bioactive interleukin (IL)-1β. Excessive activation of the NLRP3 inflammasome is mechanistically linked to diverse pathophysiological conditions, including airway inflammation. Here, we discovered that Curcuma phaeocaulis can suppress caspase-1 activation and processing of pro-IL-1β into mature cytokine in macrophages stimulated with NLRP3 inflammasome activators, such as SiO₂ or TiO₂ nanoparticles. Furthermore, in the bronchoalveolar lavage fluids of animals administered the nanoparticles, the in vitro effects of C. phaeocaulis translated into a decrease in IL-1β levels and cell infiltration. Demethoxycurcumin (DMC) and curcumin were found to be responsible for the inflammasome inhibitory activity of C. phaeocaulis. Interestingly, in contrast to the previously reported higher antioxidant- and NFκB-inhibitory activities of curcumin, DMC exhibited approximately two-fold stronger potency than curcumin against nanoparticle induced activation of NLRP3 inflammasome. In the light of these results, both compounds seem to act independently of their antioxidant- and NFκB-inhibitory properties. Although how C. phaeocaulis inhibits nanoparticle-activated NLRP3 inflammasome remains to be elucidated, our results provide a basis for further research on C. phaeocaulis extract as an anti-inflammatory agent for the treatment of disorders associated with excessive activation of NLRP3 inflammasome.

Schwann cell differentiation involves a dynamic interaction of signaling cascades. However, much remains to be elucidated regarding the function of signaling molecules that differ depending on the context in which the molecules are engaged. Here, we identified a small molecule, dabrafenib, which promotes Schwann cell differentiation in vitro and exploited this compound as a pharmacological tool to understand the molecular mechanisms regulating Schwann cell differentiation. The results indicated that dabrafenib inhibited ERK phosphorylation and enhanced ErbB2 autophosphorylation and Akt phosphorylation, and the effects of dabrafenib on ErbB2 and Akt phosphorylation were phenocopied by pharmacological inhibition of the MEK-ERK signaling pathway. However, the small molecule inhibitors of MEK and ERK had no effect on the expression of Oct6 and EGR2, which are key transcription factors that drive Schwann cell differentiation. In addition, pharmacological inhibition of phosphatidylinositol-3-kinase (PI3K) almost completely interfered with dabrafenib-induced Schwann cell differentiation. These results suggest that the ErbB2-PI3K-Akt axis is required for the induction of Schwann cell differentiation by dabrafenib in vitro. Although additional molecules targeted by dabrafenib remain to be identified, our data provides insights into the crosstalk that exists between the MEK-ERK signaling pathway and the PI3K-Akt axis in Schwann cell differentiation.

Background: Shilajit is a natural phytocomplex known for centuries in Ayurveda traditional medicine for its antioxidant, immunomodulatory, and neuroprotective properties. However, there is little published scientific evidence to support these acclaimed properties.Methods: The safety, regarding the heavy metal content, component analysis, the neuroprotective effects and amyloid beta (Aβ)-induced cytotoxicity and inflammation of 3 samples of Shilajit derived from different geographical origins were assessed. Neuroprotective effects of Shilajit were examined using neuroblastoma cell lines (SH-SY5Y and IMR-32) and cell viability assays. The inhibitory effect on the proinflammatory cytokine derived from macrophage cells was assessed using bone marrow-derived macrophage cells in vitro and in a murine model of Aβ-induced inflammation (ex vivo analysis).Results: The results showed that a daily dose of each Shilajit sample were within the permissible heavy metal limit established by the United States Food and Drug Administration. The 3 Shilajit samples alleviated Aβ-induced toxicity in neuronal cells. One sample derived from the Altai Mountains suppressed Aβ-induced processing of pro-interleukin (pro-IL)-1β into mature, biologically active IL-1β in macrophages. This Shilajit sample inhibited Aβ-induced production of the proinflammatory cytokine IL-1β in the brain (ex vivo analysis). In component analysis, this sample was enriched in salicyluric acid.Conclusion: Shared and distinct properties were observed among the 3 Shilajit samples concerning their neuroprotective effects, and regarding safety, the daily dose of each Shilajit had a safe level of heavy metal content. Salicyluric acid in Shilajit may be important in mitigating Aβ-induced inflammatory cytokine but more research is necessary.

Osteoporosis is a clinical condition characterized by low bone strength that leads to an increased risk of fracture. Strategies for the treatment of osteoporosis involve inhibition of bone resorption by osteoclasts and an increase of bone formation by osteoblasts. Here, we identified the extract derived from the stem part of Edgeworthia papyrifera that enhanced differentiation of MC3T3-E1 cells to osteoblast-like cells and inhibited osteoclast differentiation of RAW 264.7 cells in vitro. In support of our observation, rutin and daphnoretin, which were previously reported to inhibit osteoclast differentiation, were identified in E. papyrifera extract. In an animal model of osteoporosis, the ovariectomy-induced increases in bone resorption biomarkers such as pyridinoline and tartrate-resistant acid phosphatase were significantly reduced by E. papyrifera extract administration at 25.6 and 48.1%, respectively. Furthermore, the ovariectomy-induced bone loss in animal models of osteoporosis was significantly prevented by the administration of E. papyrifera in our study. Taking these observations into account, we suggest that E. papyrifera is an interesting candidate for further exploration as an anti-osteoporotic agent.