The TLR4/NF-κB/NLRP3 and Nrf2/HO-1 pathways mediate the neuroprotective effects of alkaloids extracted from Uncaria rhynchophylla in Parkinson's disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Parkinson's disease (PD) is the second most common neurodegenerative disorder with limited therapeutic options available. Neuroinflammation plays an important role in the occurrence and development of PD. Alkaloids extracted from Uncaria rhynchophylla (URA), have emerged as a potential neuroprotective agent because of its anti-inflammatory and anti-oxidant properties. Nevertheless, the underlying mechanism by which URA exerts neuroprotective effects in PD remains obscure. AIM OF THE STUDY: The main aim of this study was to investigate the neuroprotective effects and underlying mechanism of URA in the treatment of PD through in vivo and in vitro models, focusing on the neuroinflammation and oxidative stress pathways. MATERIALS AND METHODS: The protective effects of URA against PD were evaluated by neurobehavioral tests, immunohistochemistry, serum biochemical assays, and real-time quantitative polymerase chain reaction in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice. The role of the TLR4/NF-κB/NLRP3 pathway and the Nrf2/HO-1 pathway in URA-mediated effects was examined in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and a microglia-neuron coculture system. RESULTS: URA significantly alleviated motor deficits and dopaminergic neurotoxicity, and reversed the abnormal secretion of inflammatory and oxidative stress factors in the serum of MPTP-induced mice. URA suppressed the gene expression of Toll-like receptor 4 (TLR4), NOD-like receptor protein 3, and cyclooxygenase 2 (COX2) in the striatum of PD mice. Further studies indicated that URA inhibited activation of the TLR4/NF-κB/NLRP3 pathway and enhanced activation of the Nrf2/HO-1 pathway, reduced reactive oxygen species (ROS) production, and reversed the secretion of inflammatory mediators in LPS-stimulated BV-2 microglial cells, thereby alleviating neuroinflammatory damage to SH-SY5Y neuronal cells. CONCLUSION: URA exerted neuroprotective effects against PD mainly by the inhibition of the TLR4/NF-κB/NLRP3 pathway and activation of the Nrf2/HO-1 antioxidant pathway, highlighting URA as a promising candidate for PD treatment.

Rhynchophylline alleviates neuroinflammation and regulates metabolic disorders in a mouse model of Parkinson's disease.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder with limited therapeutic agents. Rhynchophylline (RIN), a tetracyclic oxindole alkaloid isolated from Uncaria rhynchophylla, has multiple neuropharmacological activities, including anti-inflammatory, anti-depression, anti-neurodegenerative disease, and anti-drug addiction. Though it is reported that RIN exerts a neuroprotective effect against PD, the underlying protective mechanism remains obscure. In this study, a mass spectrometry-based metabolomic strategy combined with neurobehavioral tests, serum biochemical assays, and immunohistochemistry were employed to decipher the protective mechanism of RIN against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced subacute PD in mice. Our results indicated that RIN significantly improved the MPTP-induced behavioral abnormalities, reduced the loss of dopaminergic neurons, and reversed the secretion of inflammatory cytokines and oxidative stress indicators. Further studies showed that RIN significantly suppressed the expression of toll-like receptor 4, NOD-like receptor protein 3, and cyclooxygenase 2 in the mouse striatum. The results of serum metabolomics showed that RIN could ameliorate metabolic disorders in PD mainly through the regulation of retinol metabolism, arachidonic acid metabolism, glycerophospholipid metabolism, and purine metabolism. These pieces of evidence revealed that RIN is a promising drug candidate for PD by alleviating neuroinflammation and maintaining metabolic homeostasis.

Multiple mitochondria-targeted components screened from Sini decoction improved cardiac energetics and mitochondrial dysfunction to attenuate doxorubicin-induced cardiomyopathy.

Rationale: Sini decoction (SND) is an efficient formula against DOX-induced cardiomyopathy (DCM), but the active ingredient combination (AIC) and mechanisms of SND remain unclear. Therefore, the present study aimed to identify the AIC and elucidate the underlying mechanism of AIC on DCM. Methods: The AIC were screened by a novel comprehensive two-dimensional cardiac mitochondrial membrane chromatography (CMMC)-TOFMS analysis system and further validated by cell viability, reactive oxygen species (ROS) generation, ATP level, and mitochondrial membrane potential in DOX-induced H9c2 cell injury model. Then, an integrated model of cardiac mitochondrial metabolomics and proteomics were applied to clarify the underlying mechanism in vitro. Results: The CMMC column lifespan was significantly improved to more than 10 days. Songorine (S), neoline, talatizamine, 8-gingerol (G) and isoliquiritigenin (I), exhibiting stronger retention on the first-dimension CMMC column, were screened to have protective effects against DOX cardiotoxicity in the H9c2 cell model. S, G and I were selected as an AIC from SND according to the bioactivity evaluation and the compatibility theory of SND. The combined in vitro use of S, G and I produced more profound therapeutic effects than any component used individually on increasing ATP levels and mitochondrial membrane potential and suppressing intracellular ROS production. Moreover, SGI attenuated DCM might via regulating mitochondrial energy metabolism and mitochondrial dysfunction. Conclusions: The provided scientific evidence to support that SGI combination from SND could be used as a prebiotic agent for DCM. Importantly, the proposed two-dimensional CMMC-TOFMS analytical system provides a high-throughput screening strategy for mitochondria-targeted compounds from natural products, which could be applied to other subcellular organelle models for drug discovery.

Untargeted metabolomics reveals the combination effects and mechanisms of Huangqi-fuzi herb-pair against doxorubicin-induced cardiotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Qifu decoction (QFD) is a famous traditional Chinese medicine (TCM) composed of Astragali Radix (HuangQi) and Aconiti Lateralis Radix Praeparaia (Fuzi), which can alleviate doxorubicin (DOX)-induced cardiotoxicity (DIC). However, its protective mechanism remains obscured. AIM OF THE STUDY: The present study aimed to uncover the cardioprotective mechanism and the synergistic effect of QFD against DIC in mice. MATERIALS AND METHODS: The cardioprotective activity of QFD against DIC was assessed by electrocardiogram, serum biochemical assays and histopathology. Mass spectrometry-based metabolomic approach was conducted to elucidate the preventive mechanisms of QFD, HuangQi decoction (HQD), and Fuzi decoction (FZD) against DIC. QFD, HQD, FZD-targeted metabolic pathways were identified and compared to investigate the synergistic mechanism of QFD by computational systems analysis. Quantitative real-time PCR (qRT-PCR) was further employed to validate the key metabolic pathways at the level of the gene. RESULTS: The electrocardiogram combined with the biochemical analysis and histopathology showed that the protection effects were sorted as QFD > HQD ≈ FZD. A total of 41 metabolites contributing to DIC were identified in the mice serum, among which 32, 12 and 10 metabolites were significantly reverted by QFD, HQD and FZD, respectively. Metabolic pathway analysis revealed that DOX perturbed 12 metabolic pathways, and QFD, HQD, and FZD-treated groups could significantly reverse 12, 7 and 6 metabolic pathways of these 12 metabolic pathways. Metabolic pathway and qRT-PCR revealed that QFD could protect DIC mainly by regulating energy metabolism, amino acids metabolism, arachidonic acid metabolism and glycerophospholipid metabolism, and HQD and FZD mutually reinforced each other. CONCLUSION: These evidences revealed that QFD was a promising drug candidate for DIC by maintaining metabolic homeostasis. Meanwhile, this work provided a useful approach for evaluating the efficacy and the synergistic effects of TCMs against cardiomyopathy.