Extract of Aster glehni ameliorates potassium oxonate-induced hyperuricemia by modulating renal urate transporters and renal inflammation by suppressing TLR4/MyD88 signaling

Research progress of treating hyperuricemia in rats and mice with traditional Chinese medicine

Hyperuricemia (HUA) is a common chronic metabolic disease caused by abnormal purine metabolism and uric acid excretion. Despite extensive research on HUA, no clear treatment has been found so far. Improving purine metabolism and promoting uric acid excretion is crucial for the effective treatment of HUA. In recent years, traditional Chinese medicine and traditional Chinese medicine prescriptions have shown good effects in treating HUA. This article summarizes the latest progress in treating HUA in rats and mice using traditional Chinese medicine and prescriptions, elaborates on the pathogenesis of HUA, explores the application of commonly used traditional Chinese medicine treatment methods and prescriptions, and discusses the previous pharmacological mechanisms. In general, our research indicates that traditional Chinese medicine can effectively relieve the symptoms related to elevated uric acid levels in HUA rats and mice. However, further exploration and research are needed to verify its efficacy, safety, and feasibility.

The Terminalia chebula Retz extract treats hyperuricemic nephropathy by inhibiting TLR4/MyD88/NF-κB axis

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperuricemic nephropathy (HN) is a renal injury caused by hyperuricemia and is the main cause of chronic kidney disease and end-stage renal disease. ShiWeiHeZiSan, which is composed mainly of components of Terminalia chebula Retz. And is recorded in the Four Medical Tantras, is a typical traditional Tibetan medicinal formula for renal diseases. Although T. chebula has been reported to improve renal dysfunction and reduce renal cell apoptosis, the specific mechanism of the nephroprotective effects of T. chebula on HN is still unclear.

AIM OF THE STUDY

This study was conducted to evaluate the effects and specific mechanism of T. chebula extract on HN through network pharmacology and in vivo and in vitro experiments.

MATERIALS AND METHODS

Potassium oxalate (1.5 g/kg) and adenine (50 mg/kg) were combined for oral administration to establish the HN rat model, and the effects of T. chebula extract on rats in the HN model were evaluated by renal function indices and histopathological examinations. UPLC-Q-Exactive Orbitrap/MS analysis was also conducted to investigate the chemical components of T. chebula extract, and the potential therapeutic targets of T. chebula in HN were predicted by network pharmacology analysis. Moreover, the activation of potential pathways and the expression of related mRNAs and proteins were further observed in HN model rats and uric acid-treated HK-2 cells.

RESULTS

T. chebula treatment significantly decreased the serum uric acid (SUA), blood urea nitrogen (BUN) and serum creatinine (SCr) levels in HN rats and ameliorated renal pathological injury and fibrosis. A total of 25 chemical components in T. chebula extract were identified by UPLC-Q-Exactive Orbitrap/MS analysis, and network pharmacology analysis indicated that the NF-κB pathway was the potential pathway associated with the therapeutic effects of T. chebula extract on HN. RT‒PCR analysis, immunofluorescence staining and ELISA demonstrated that the mRNA and protein levels of TLR4 and MyD88 were significantly decreased in the renal tissue of HN rats after treatment with T. chebula extract at different concentrations, while the phosphorylation of P65 and the secretion of TNF-α and IL-6 were significantly inhibited. The results of in vitro experiments showed that T. chebula extract significantly decreased the protein levels of TLR4, MyD88, p-IκBα and p-P65 in uric acid-treated HK-2 cells and inhibited the nuclear translocation of p65 in these cells. In addition, the expression of inflammatory factors (IL-1β, IL-6 and TNF-α) and fibrotic genes (α-SMA and fibronectin) was significantly downregulated by T. chebula extract treatment, while E-cadherin expression was significantly upregulated.

CONCLUSION

T. chebula extract exerts nephroprotective effects on HN, such as anti-inflammatory effects and fibrosis improvement, by regulating the TLR4/MyD88/NF-κB axis, which supports the general use of T. chebula in the management of HN and other chronic kidney diseases.

The Anti-Inflammatory Mechanism of Flaxseed Linusorbs on Lipopolysaccharide-Induced RAW 264.7 Macrophages by Modulating TLR4/NF-κB/MAPK Pathway

Flaxseed linusorbs (FLs), cyclic peptides derived from flaxseed oils, have shown multiple activities such as anticancer, antibacterial, and anti-inflammatory effects. However, the anti-inflammatory monomers of FLs and their mechanisms are still unclear. In this study, we have elucidated that FLs suppress the modulation of NF-κB/MAPK signaling pathways by targeting the inhibition of activating TLR4 in LPS-induced RAW 264.7 cells. Therefore, the transcription and expression of inflammatory cytokines (i.e., TNF-α, IL-1β, and IL-6) and inflammatory mediator proteins (i.e., iNos and Cox-2) were significantly suppressed by FLs. In addition, an in silico study discovered that eight monomers of FLs showed high-affinity bindings with TLR4. In silico data combined with HPLC results indicated that FLA and FLE, accounting for 44%, were likely the major anti-inflammatory monomers in FLs. In summary, FLA and FLE were proposed as the main anti-inflammatory active cyclopeptides via hindering TLR4/NF-κB/MAPK signaling pathways, suggesting the potential use of food-derived FLs as natural anti-inflammatory supplements in a daily diet.