A Novel Method for Identifying Parkin Binding Agents in Complex Preparations of Herbal Medicines.

Parkin is a crucial E3 ubiquitin ligase for initiating mitophagy through the PINK1/Parkin pathway. Regulating the expression and activity of parkin can remedy mitophagy and human disease. We developed an efficient method to isolate natural parkin ligands from herbal medicines by combining centrifugal ultrafiltration and liquid chromatography/mass spectrometry. The heterologous expression technology identified functionally active and pure parkin proteins. After evaluating the reliability of the method using DL-selenomethionine and DL-dithiothreitol as positive controls, this method was successfully applied to capture parkin ligands from Polygoni Cuspidati Rhizoma et Radix and Sophorae Flavescentis Radix. LC/MS identified seven novel parkin-targeting compounds, namely, 7,4'-dihydroxy-5-methoxy-8-(γ, γ-dimethylallyl)-flavanone, kushenol I, kurarinone, sophoraflavanone G, torachrysone-8-O-glucoside, apigenin, and emodin, supported by the molecular docking analysis. Five of the seven novel compounds (kushenol I, kurarinone, sophoraflavanone G, apigenin, and emodin) can activate parkin in in vitro autoubiquitination assays. Meanwhile, kushenol I and kurarinone had antisteatosis activity in fat emulsion-damaged human hepatocytes. These results confirmed the effectiveness of the method for identifying parkin ligands from complex preparations, useful to advance drug discovery from medicinal herbs.

The Impact of Traditional Chinese Medicine on Mitophagy in Disease Models.

Mitophagy plays an important role in maintaining mitochondrial quality and cell homeostasis through the degradation of damaged, aged, and dysfunctional mitochondria and misfolded proteins. Many human diseases, particularly neurodegenerative diseases, are related to disorders of mitochondrial phagocytosis. Exploring the regulatory mechanisms of mitophagy is of great significance for revealing the molecular mechanisms underlying the related diseases. Herein, we summarize the major mechanisms of mitophagy, the relationship of mitophagy with human diseases, and the role of traditional Chinese medicine (TCM) in mitophagy. These discussions enhance our knowledge of mitophagy and its potential therapeutic targets using TCM.

Targeting PINK1 Using Natural Products for the Treatment of Human Diseases.

PINK1, also known as PARK6, is a PTEN-induced putative kinase 1 that is encoded by nuclear genes. PINK1 is ubiquitously expressed and regulates mitochondrial function and mitophagy in a range of cell types. The dysregulation of PINK1 is associated with the pathogenesis and development of mitochondrial-associated disorders. Many natural products could regulate PINK1 to relieve PINK1-associated diseases. Here, we review the structure and function of PINK1, its relationship to human diseases, and the regulation of natural products to PINK1. We further highlight that the discovery of natural PINK1 regulators represents an attractive strategy for the treatment of PINK1-related diseases, including liver and heart diseases, cancer, and Parkinson's disease. Moreover, investigating PINK1 regulation of natural products can enhance the in-depth comprehension of the mechanism of action of natural products.

Jiuzhuan Huangjing Pills relieve mitochondrial dysfunction and attenuate high-fat diet-induced metabolic dysfunction-associated fatty liver disease.

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common global chronic liver disease. Jiuzhuan Huangjing Pills (JHP) have been used for the treatment of human disease for over a thousand years, but their efficacy and underlying mechanism(s) of action against MAFLD are unknown. We investigated the alleviating effects of JHP on high-fat diet (HFD)-induced MAFLD. METHODS: In vitro and in vivo methods were used to evaluate the effects of JHP on MAFLD. L02 adipocyte models were induced by fat emulsion and adipocytes were treated with JHP for 24 h. MAFLD rat models were induced by HFD-feeding and were intragastrically administered JHP for 12 weeks. Changes in fat accumulation, L02 cell damage, body weight, food intake, histological parameters, organ indexes, biochemical parameters, and mitochondrial indicators including ultrastructure, oxidative stress, energy metabolism, and fatty acid metabolism were investigated. RESULTS: JHP attenuated the increase in levels of total cholesterol, triglyceride, low density lipoprotein cholesterol, alanine transaminase, and aspartate transaminase levels, and significantly increased high density lipoprotein cholesterol. JHP up-regulated levels of glutathione (GSH) and superoxide dismutase (SOD), and down-regulated malondialdehyde (MDA). JHP afforded protection to the mitochondrial ultrastructure, and inhibited the HFD-induced increase in MDA and the reduction of SOD, GSH, ATP synthase, and complex I and II, in liver mitochondria. JHP regulated the expression of ß-oxidation genes, including acyl-CoA dehydrogenase, cyl-CoA dehydrogenase long chain, carnitine palmitoyltransferase 1A, carnitine palmitoyltransferase 1B, peroxisomal proliferator-activated receptor-gamma coactivator-1α and peroxide proliferator activated receptor α. CONCLUSION: JHP alleviates HFD-induced MAFLD through the protection of mitochondrial function.

Remedying the Mitochondria to Cure Human Diseases by Natural Products.

Mitochondria are the 'engine' of cells. Mitochondrial dysfunction is an important mechanism in many human diseases. Many natural products could remedy the mitochondria to alleviate mitochondria-involved diseases. In this review, we summarized the current knowledge of the relationship between the mitochondria and human diseases and the regulation of natural products to the mitochondria. We proposed that the development of mitochondrial regulators/nutrients from natural products to remedy mitochondrial dysfunction represents an attractive strategy for a mitochondria-involved disorder therapy. Moreover, investigating the mitochondrial regulation of natural products can potentiate the in-depth comprehension of the mechanism of action of natural products.

Muscle Fatigue-Alleviating Effects of a Prescription Composed of Polygonati Rhizoma and Notoginseng Radix et Rhizoma.

Long-term muscle fatigue is a major cause of injury. Drugs/nutrients from herbal medicines that prevent fatigue remain a major research focus. In China, a prescription composed of Polygonati Rhizoma and Notoginseng Radix et Rhizoma has been commonly used as a herb and food nutrient, providing protection against fatigue in the clinic. To date, the mechanisms through which this prescription prevented fatigue are unknown. Here, we identified the effects of this prescription on muscle fatigue based on energy and oxidation regulation. Fatigue mouse models were produced through weight-bearing exhaustive swimming. Mice were intragastrically administered prescription extracts (1 and 2 g/kg) for four weeks. Changes in exhaustive swimming times, antifatigue biochemical indicators, oxidative status, and energy metabolism were investigated. The prescription prolonged the exhaustive swimming time of the mice. The content of lactic acid and blood urea nitrogen in the serum was also markedly reduced by the prescription. The content of liver glycogen and lactate dehydrogenase in the serum increased. The prescription also significantly reduced malondialdehyde levels and increased the levels of superoxide dismutase and glutathione peroxidase. The levels of ATPase, complexes I and II in the mitochondria of hind-leg skeletal muscle, and serum creatine kinase also increased in response to the prescription. Our results indicated that the prescription could effectively alleviate muscle fatigue status by promoting energy metabolism and antioxidation ability. The prescription therefore represents a useful drug/nutrient strategy to alleviate muscle fatigue.

Mitochondrial metabolomic profiling for elucidating the alleviating potential of Polygonatum kingianum against high-fat diet-induced nonalcoholic fatty liver disease.

BACKGROUND: Developing mitochondrial regulators/nutrients from natural products to remedy mitochondrial dysfunction represent attractive strategies for therapy of non-alcoholic fatty liver disease (NAFLD). Polygonatum kingianum (PK) has been traditionally used in China as a medicinal and nutritional ingredient for centuries and can alleviate high-fat diet (HFD)-induced NAFLD by promoting mitochondrial functions. To date, the underlying molecular mechanism of PK for treating mitochondrial dysfunctions and thus alleviating NAFLD remains unclear. AIM: To identify the molecular mechanism behind the mitochondrial regulatory action of PK against HFD-induced NAFLD in rats. METHODS: NAFLD model was induced in rats with HFD. The rats were intragastrically administered PK (4 g/kg per day) for 14 wk. Metabolites in hepatic mitochondrial samples were profiled through ultra-high performance liquid chromatography/mass spectrometry followed by multivariate statistical analysis to find the potential biomarkers and metabolic pathways. RESULTS: PK significantly restored the metabolites' levels in the mitochondrial samples. Ten potential biomarkers were identified in the analyzed samples. These biomarkers are involved in riboflavin metabolism. CONCLUSION: PK can alleviate HFD-induced NAFLD by regulating the riboflavin metabolism and further improving the mitochondrial functions. Thus, PK is a promising mitochondrial regulator/nutrient for alleviating NAFLD-associated diseases.

Efficiently Capturing Mitochondria-Targeted Constituents with Hepatoprotective Activity from Medicinal Herbs.

Targeting mitochondria as a hepatic-protective strategy has gained attention, because of their important roles in energy production, adjustment of apoptosis, and generation of reactive oxygen species. To promote the discovery of natural mitochondria-targeted hepatic-protectants, we established a hepatocellular mitochondria-based capturing method by coupling affinity ultrafiltration with liquid chromatography/mass spectrometry (LC/MS), which is suitable for identifying mitochondrial ligands from medicinal herbs (MHs). After evaluating the feasibility of the method, it was applied for capturing mitochondria-targeting constituents from Peucedani Radix extract. A total of 10 active compounds were identified by LC/MS, all of which were newly identified mitochondrial ligands. The mitochondria-remedying activity of 4 of the 10 hits was confirmed by pharmacological tests in vitro. Additionally, the hepatic-protective abilities of 4 hits were verified in both carbon tetrachloride-damaged liver L02 cells and mice. These results indicated that the method could be used for identifying hepatic mitochondria-targeting constituents in MHs, which might be beneficial for hepatic-protective development.

Identification of Mitochondrial Ligands with Hepatoprotective Activity from Notopterygii Rhizoma et Radix Using Affinity Ultrafiltration/Liquid Chromatography/Mass Spectrometry.

In recent years, the incidence of diseases associated with hepatic injury has increased in prevalence. Targeting the mitochondria to protect liver function has gained momentum due to their central role in energy production, apoptotic cell death, oxidative stress, calcium homeostasis, and lipid metabolism. In this study, we employed a hepatic mitochondria-based centrifugal ultrafiltration/liquid chromatography/mass spectrometry method (CM-HMC) to identify hepatic mitochondria ligands from medicinal herbs (MHs) including Notopterygii Rhizoma et Radix (NRR) that possess hepatic-protective effects. A total of 4 newly identified mitochondrial ligands were successfully identified by CM-HMC. The mitochondria-regulating activities of 3 of the 4 hits were confirmed using isolated mitochondria. The hepatic-protective effects of one of these hits were validated in carbon tetrachloride-damaged human liver L02 cell models. We have thus identified new natural hepatic-protectants that enhance our understanding of the hepatic-protective mechanisms of MHs. CM-HMC was proven to efficiently screen for mitochondrial ligands from MHs.

Integrated metabolomic profiling for analysis of antilipidemic effects of Polygonatum kingianum extract on dyslipidemia in rats.

AIM: To identify the effects and mechanism of action of Polygonatum kingianum (P. kingianum) on dyslipidemia in rats using an integrated untargeted metabolomic method. METHODS: A rat model of dyslipidemia was induced with a high-fat diet (HFD) and rats were given P. kingianum [4 g/(kg•d)] intragastrically for 14 wk. Changes in serum and hepatic lipid parameters were evaluated. Metabolites in serum, urine and liver samples were profiled using ultra-high performance liquid chromatography/mass spectrometry followed by multivariate statistical analysis to identify potential biomarkers and metabolic pathways. RESULTS: P. kingianum significantly inhibited the HFD-induced increase in total cholesterol and triglyceride in the liver and serum. P. kingianum also significantly regulated metabolites in the analyzed samples toward normal status. Nineteen, twenty-four and thirty-eight potential biomarkers were identified in serum, urine and liver samples, respectively. These biomarkers involved biosynthesis of phenylalanine, tyrosine, tryptophan, valine, leucine and isoleucine, along with metabolism of tryptophan, tyrosine, phenylalanine, starch, sucrose, glycerophospholipid, arachidonic acid, linoleic acid, nicotinate, nicotinamide and sphingolipid. CONCLUSION: P. kingianum alleviates HFD-induced dyslipidemia by regulating many endogenous metabolites in serum, urine and liver samples. Collectively, our findings suggest that P. kingianum may be a promising lipid regulator to treat dyslipidemia and associated diseases.