Sasanquasaponin-induced cardioprotection involves inhibition of mPTP opening via attenuating intracellular chloride accumulation

Advances in Separation, Biological Properties, and Structure-Activity Relationship of Triterpenoids Derived from Camellia oleifera Abel

Extensive research has been conducted on Camellia oleifera Abel., a cultivar predominantly distributed in China, to investigate its phytochemical composition, owning to its potential as an edible oil crop. Pentacyclic triterpene saponins, as essential active constituents, play a significant role in contributing to the pharmacological effects of this cultivar. The saponins derived from C. oleifera (CoS) offer a diverse array of bioactivity benefits, including antineoplastic/bactericidal/inflammatory properties, cardiovascular protection, neuroprotection, as well as hypoglycemic and hypolipidemic effects. This review presents a comprehensive analysis of the isolation and pharmacological properties of CoS. Specially, we attempt to reveal the antitumor structure-activity relationship (SAR) of CoS-derived triterpenoids. The active substitution sites of CoS, namely, C-3, C-15, C-16, C-21, C-22, C-23, and C-28 pentacyclic triterpenoids, make it a unique and highly valuable substance with significant medicinal and culinary applications. As such, CoS can play a critical role in transforming people's lives, providing unique medicinal benefits, and contributing to the advancement of both medicine and cuisine.

Sasanquasaponin from Camellia oleifera Abel Exerts an Anti-Inflammatory Effect in RAW 264.7 Cells via Inhibition of the NF-κB/MAPK Signaling Pathways

Sasanquasaponin (SQS), a secondary metabolite that is derived from Camellia seeds, reportedly possesses notable biological properties. However, the anti-inflammatory effects of SQS and its underlying mechanisms remain poorly explored. Herein, we aimed to investigate the anti-inflammatory properties of SQS against lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 cells, focusing on the nuclear factor-κB (NF-κB) and MAPK signaling pathways. SQS was isolated using a deep eutectic solvent and D101 macroporous adsorption resin and analyzed using high-performance liquid chromatography. The viability of LPS-stimulated RAW264.7 was assessed using the CCK-8 assay. The presence of reactive oxygen species (ROS) was evaluated using 2',7'-dichlorofluorescein-diacetate. The expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were detected using reverse transcription-quantitative PCR and ELISA. Western blot was performed to analyze the protein expression of LPS-induced RAW264.7 cells. Herein, SQS exhibited anti-inflammatory activity: 30 μg/mL of SQS significantly reduced ROS generation, inhibited the LPS-induced expression of iNOS and COX-2, and attenuated the production of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. The anti-inflammatory activity was potentially mediated by inhibiting the phosphorylation of IκBα and p65 in the NF-κB signaling pathway and the phosphorylation of ERK and JNK in the MAPK signaling pathway. Accordingly, SQS could inhibit inflammation in LPS-induced RAW264.7 cells by suppressing the NF-κB and MAPK signaling pathways. This study demonstrated the potential application of SQS as an anti-inflammatory agent.

10-Gingerol alleviates hypoxia/reoxygenation-induced cardiomyocyte injury through inhibition of the Wnt5a/Frizzled-2 pathway

10-Gingerol (10-Gin), an active ingredient extracted from ginger, has been reported to have beneficial effects on the cardiovascular system. However, 10-Gin has not been proved to offer protection against cardiomyocyte injury induced by hypoxia/reoxygenation (H/R). This study aimed to investigate the protective effects of 10-Gin against H/R-induced injury and its potential mechanisms in cardiomyocytes. A H/R injury model of H9c2 cardiomyocytes was established using 600 μmol/L CoCl2 to induce hypoxia in the cells for 24 hr and then reoxygenated for 3 hr. 10-Gin was pretreated with H9c2 cardiomyocytes for 24 hr to assess its cardiomyocyte protection. Our results showed that 10-Gin improved the viability of H9c2 cardiomyocytes in the H/R model and decreased the activities of creatine kinase, lactate dehydrogenase, and the generation of reactive oxygen species. By intracellular Ca2+ ([Ca2+]i) fluorescence, we found that 10-Gin could significantly reduce the [Ca2+]i concentration. 10-Gin administration increased the activities of antioxidase and reduced malondialdehyde content and inflammatory cytokine levels. 10-Gin also reduced the apoptosis levels. Importantly, 10-Gin administration decreased the gene and protein expressions of Wnt5a and Frizzled-2. In conclusion, 10-Gin alleviates H/R-induced cardiomyocyte injury, which is associated with the antioxidation, anti-inflammation, antiapoptosis action, and reduction of [Ca2+]i overload by suppressing the Wnt5a/Frizzled-2 pathway.

Targeting mitochondrial calcium pathways as a potential treatment against Parkinson's disease

Parkinson's disease (PD) is a major health problem worldwide affecting millions of people and is a result of neurodegeneration in a small part of the brain known as substantia nigra pars compacta. Aberration in mitochondrial Ca²⁺ homeostasis plays, among several other factors, an important role for the neuronal loss in PD. Mitochondria are vital for cellular physiology, e.g. for ATP generation, and mitochondrial Ca²⁺ is a key player in cell functioning and survival. Mitochondrial Ca²⁺ homeostasis is maintained by a fine balance between the activities of proteins mediating the influx and efflux of Ca²⁺ across mitochondrial membranes. Malfunctioning of these proteins leading to Ca²⁺ overload promotes ROS generation, which induces cell death by triggering the opening of mitochondrial permeability transition pore. Till now PD remains incurable and the "gold standard" drug which can only delays the disease progression is l-Dopa from the 1960s and therefore, the situation warrants the search for novel targets for the treatment of the PD patients. In this review, we summarize the current views that suggest mitochondrial Ca²⁺ regulatory pathways are good candidates for the treatment of PD.

Camellia cake extracts reduce burn injury through suppressing inflammatory responses and enhancing collagen synthesis

Background

Burn injury accidents happen in our daily life, and the burn mortality is especially high in the low-to-middle-income countries. Camellia cake extracts (CCEs) are compound extracts from Camellia cake, and the major ingredients in CCEs may have antimicrobial, anti-oxidative, and anti-inflammatory effects. However, the effects of CCEs on burn inflammation and injury remain unknown.

Objective

This study is to investigate the effects of CCEs in burn injury and explore its mechanism.

Design

First, CCEs were identified to mainly contain camelliaside A and B using Ultra High Performance Liquid Chromatography-Time of Flight Mass Spectrometer (UHPLC-TOF-MS) method. Second, the CCEs' effect on burn was tested. Burn was induced by boiling water in mice, and then CCEs (30, 50, and 100 mg/mL) were applied on the damaged skin at 3, 7, and 14 days after burn induction.

Results

The results showed that CCEs protected the skin from burn-induced inflammation and enhanced the wound healing in a dose-dependent manner. CCEs decreased the expression levels of various cytokines including IL-6, TNF-α, IL-1β, MCP-1, TGF-β, and IL-10, as well as inflammatory related factors iNOS. Moreover, CCEs increased the levels of collagens, including the mRNA of COLα-1 and COL-3, and inhibited the mRNA of MMP-1 and TIMP-1, and increased the collagen staining. CCEs also reversed the impairment of activity levels of anti-oxidative enzymes. Furthermore, CCEs suppressed the gene expression of pro-inflammatory cytokines in LPS-stimulated human skin keratinocyte, possibly through inhibiting NF-κB signaling pathway. In addition, toxicological safety experiments on CCEs showed that the oral median lethal dose (LD50) was 2,000 mg/kg, the percutaneous LD50 was greater than 2,000 mg/kg, and CCEs did not cause gene mutation.

Conclusion

CCEs exert a potent anti-inflammatory effect against burn damage in mice. And toxicological safety experiments suggest that CCEs are safe for usage.

Eriodictyol protects H9c2 cardiomyocytes against the injury induced by hypoxia/reoxygenation by improving the dysfunction of mitochondria

Myocardial infarction is a leading cause of mortality worldwide, while myocardial ischemia and timely reperfusion contribute to myocardial injury. The mitochondria are involved in the injury and mediate the apoptosis of cardiomyocytes. In order to develop novel therapeutic approaches for myocardial infarction, the present study evaluated the myocardial protective effects of eriodictyol and investigated relevant mechanisms in H9c2 cardiomyocytes. As a result, eriodictyol was observed to improve the H9c2 cardiomyocyte viability and block the leakage of cytosolic lactate dehydrogenase under hypoxia/reoxygenation. In addition, the dysfunction of mitochondria induced by hypoxia/reoxygenation was ameliorated by eriodictyol through suppressing the overload of intracellular Ca²⁺, preventing overproduction of reactive oxygen species, blocking mitochondrial permeability transition pore opening, increasing mitochondrial membrane potential level and decreasing ATP depletion. Finally, the apoptosis of H9c2 cardiomyocyte induced by hypoxia/reoxygenation was prevented by eriodictyol through upregulation of the expression of B-cell lymphoma-2 (Bcl-2) and downregulation of the expression levels of Bcl-2-associated X protein and caspase-3. These results provided evidence for further investigation on myocardial protection and the treatment of myocardial infarction using eriodictyol.

WDR26/MIP2 interacts with VDAC1 and regulates VDAC1 expression levels in H9c2 cells

MIP2, one of WDR26 isoforms, encodes a 498 amino acid protein with an amino-terminal CTLH domain and five carboxyl-terminal WD40 motifs. MIP2 is localized to the mitochondria and protects cardiomyocytes against oxidative stress; however, nothing is known about how MIP2 confers its cytoprotection. Using co-immunoprecipitation (co-IP) method to isolate MIP2-protein complex from Sprague -Dawley rat heart, followed by mass spectrometry analysis, we have identified VDAC1, a protein located at mitochondria, as a novel MIP2-interacting protein in the myocardium of rat hearts as well as H9c2 cells. This interaction was further confirmed by co-IP assays in the myocardial tissues and H9c2 cardiomyocytes, and by protein overlay assay (POA) in vitro. It was shown that MIP2 overexpression alleviated the H₂O₂-induced increase of VDAC1 and cell damage, and MIP2 deficiency aggravated the increase of VDAC1 and cell damage in H₂O₂ -treated H9c2 cells. Our research suggests that the protective effect of MIP2 on the cardiomyocytes against oxidative stress is partly associated with its interaction with VDAC1 and thus inhibiting its expression.

Triterpenoid saponins from the genus Camellia: structures, biological activities, and molecular simulation for structure–activity relationship

This review summarizes the isolation, chemical identification, and biochemical activities of Camellia triterpenoid saponins, updating a previous review and encompassing all new studies through September 2017.

Thevetiaflavone from Wikstroemia indica ameliorates PC12 cells injury induced by OGD/R via improving ROS‑mediated mitochondrial dysfunction

Cerebral ischemia and following reperfusion affects many people worldwide. To discover efficient therapeutic approaches, numerous natural products have been investigated. The current study investigated the protective effects of thevetiaflavone, a natural flavonoid obtained from Wikstroemia indica, and the associated mechanisms using PC12 cells induced by oxygen and glucose deprivation. As a result, thevetiaflavone improves cell viability and suppresses the leakage of lactate dehydrogenase from the cytoplasm. Further investigation of the mechanisms demonstrated that thevetiaflavone decreases overproduction of ROS and ameliorates ROS‑mediated mitochondrial dysfunction, including collapse of mitochondrial membrane potential and mitochondrial permeability transition pore opening. Thevetiaflavone reduces the intracellular Ca2+ level, which is closely associated with mitochondrial function and interplays with ROS. Furthermore, thevetiaflavone inhibits apoptosis in PC12 cells through upregulating the expression of Bcl‑2 and downregulating that of Bax and caspase‑3 in addition to increasing the activity of caspase‑3. These results further indicate the protective effects of thevetiaflavone in vivo and its application in the clinic.