Evaluation of hypoglycemic effects of polyphenols and extracts from Penthorum chinense

Evidence of traditional Chinese medicine for treating type 2 diabetes mellitus: from molecular mechanisms to clinical efficacy

CONTEXT

The global prevalence of type 2 diabetes mellitus (T2DM) has increased significantly in recent decades. Despite numerous studies and systematic reviews, there is a gap in comprehensive and up-to-date evaluations in this rapidly evolving field.

OBJECTIVE

This review provides a comprehensive and current overview of the efficacy of Traditional Chinese Medicine (TCM) in treating T2DM.

METHODS

A systematic review was conducted using PubMed, Web of Science, Wanfang Data, CNKI, and Medline databases, with a search timeframe extending up to November 2023. The search strategy involved a combination of subject terms and free words in English, including 'Diabetes,' 'Traditional Chinese Medicine,' 'TCM,' 'Hypoglycemic Effect,' 'Clinical Trial,' and 'Randomized Controlled Trial.' The studies were rigorously screened by two investigators, with a third investigator reviewing and approving the final selection based on inclusion and exclusion criteria.

RESULTS

A total of 108 relevant papers were systematically reviewed. The findings suggest that TCMs not only demonstrate clinical efficacy comparable to existing Western medications in managing hypoglycemia but also offer fewer adverse effects and a multitarget therapeutic approach. Five main biological mechanisms through which TCM treats diabetes were identified: improving glucose transport and utilization, improving glycogen metabolism, promoting GLP-1 release, protecting pancreatic islets from damage, and improving intestinal flora.

CONCLUSIONS

TCM has demonstrated significant protective effects against diabetes and presents a viable option for the prevention and treatment of T2DM. These findings support the further exploration and integration of TCM into broader diabetes management strategies.

Penthorum chinense Pursh leaf tea debittering mechanisms via green tea manufacturing process and its influence on NAFLD-alleviation activities

The green-tea manufacturing process showed good effect of flavor improving, debittering and shaping in making Penthorum chinensePursh leaf (PL) tea (PLT), which serves as a polyphenol dietary supplement and beverage raw material. GC-MS results showed that its unpleasant grassy odor decreased by 42.8% due to dodecanal, geranylacetone, and (E)-2-nonenal reduction, coupled with 1-hexadecanol increasing. UPLC-ESI-TOF-MS identified 95 compounds and showed that the debittering effect of green-tea manufacturing process was attributed to decreasing of flavonols and lignans, especially quercetins, kaempferols and luteolins, and increasing of dihydrochalcones which act as sweeteners bitterness-masking agents, while astringency was weakened by reducing delphinidin-3,5-O-diglucoside chloride, kaempferol-7-O-β-d-glucopyranoside, and tannins. The increase of pinocembrins and catechins in aqueous extracts of PLT, maintained its hepatoprotective, NAFLD-alleviation, and hepatofibrosis-prevention activities similar to PL in high fat-diet C57BL/6 mice, with flavonoids, tannins, tannic acids, and some newfound chemicals, including norbergenin, gomisin K2, pseudolaric acid B, tanshinol B, as functional ingredients.

Polyphenol-enriched Penthorum chinense Pursh ameliorates alcohol-related liver injury through Ras/Raf/MEK/ERK pathway: Integrating network pharmacology and experiment validation

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense Pursh (PCP) has acknowledged as an edible herbal medicinal plant for the prevention and treatment of alcoholic liver injury (ALI). However, only few of researches focus on the chemical material basis and potential mechanisms of PCP against ALI.

AIM OF THE STUDY

Herein, we explored the therapeutic effects of PCP extract against ALI based on the integration of network pharmacology, molecular docking, and experiment validation.

METHODS

Based on the standard quality control of PCP herbs by UPLC fingerprint and quantitative determination, 80% ethanol extract fraction of PCP containing more polyphenols, compared to aqueous extract fraction of PCP, were chosen for further experiments. After oral administration of PCP ethanol extract, serum pharmacochemistry based on UPLC-Q-Exactive-MS analysis was implemented to evaluate the potential effective compounds. These absorbed prototypes in PCP were used to construct network pharmacology and predict the potential mechanisms of PCP extract against ALI. Then, the predicted targets and biological mechanisms of PCP extract were validated using animal experiments and molecular docking analysis.

RESULTS

Although totally 19 polyphenol compounds were identified in PCP ethanol extract by UPLC-MS analysis, only 18 absorbed prototypes were found in the serum collected from mice at 1 h post-administration with PCP extract. These candidate active compounds were further screened into 13 compounds to construct network pharmacology and 433 targets were identified as PCP targets. GO and KEGG pathway enrichment analyses indicated that the effects of PCP extract would involve in Ras signaling pathway. The animal experiments on chronic ALI model mice shown that the oral administration of PCP can alleviate ALI by attenuating hepatic oxidative stress, inflammation and down-regulating the target proteins in Ras/Raf/MEK/ERK pathway. Molecular docking analysis revealed the good binding ability between the three polyphenols (i.e. quercetin, apigenin, thonningianin B) in PCP with the top contribution in network pharmacology, and these target proteins (Ras, Raf, MEK1/2, and ERK1/2).

CONCLUSION

Our results clarified that PCP ethanol extract could effectively alleviate ALI by down-regulating Ras/Raf/MEK/ERK signaling pathway promisingly. Quercetin, apigenin, and thonningianin B may be the active compounds of PCP, attributing to the intervention benefits of PCP against ALI.

Research progress in the molecular mechanism of ferroptosis in Parkinson's disease and regulation by natural plant products

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder of the central nervous system after Alzheimer's disease. The current understanding of PD focuses mainly on the loss of dopamine neurons in the substantia nigra region of the midbrain, which is attributed to factors such as oxidative stress, alpha-synuclein aggregation, neuroinflammation, and mitochondrial dysfunction. These factors together contribute to the PD phenotype. Recent studies on PD pathology have introduced a new form of cell death known as ferroptosis. Pathological changes closely linked with ferroptosis have been seen in the brain tissues of PD patients, including alterations in iron metabolism, lipid peroxidation, and increased levels of reactive oxygen species. Preclinical research has demonstrated the neuroprotective qualities of certain iron chelators, antioxidants, Fer-1, and conditioners in Parkinson's disease. Natural plant products have shown significant potential in balancing ferroptosis-related factors and adjusting their expression levels. Therefore, it is vital to understand the mechanisms by which natural plant products inhibit ferroptosis and relieve PD symptoms. This review provides a comprehensive look at ferroptosis, its role in PD pathology, and the mechanisms underlying the therapeutic effects of natural plant products focused on ferroptosis. The insights from this review can serve as useful references for future research on novel ferroptosis inhibitors and lead compounds for PD treatment.

Ultrasound-assisted extraction and characterization of Penthorum chinense polysaccharide with anti-inflammatory effects

Penthorum chinense has been used in both food and medication for many years, and polysaccharide of which was considered as one of the bioactive compounds. However, the extraction process of polysaccharide from P. chinense (PCP) was not well optimized. Ultrasound-assisted extractionhas been widely employed in the extraction of natural products for its compliance with the concept of green and economic chemistry. To better investigate the structure and biology activity of PCP, response surface methodology was employed to optimize the ultrasound-assisted extraction conditions of PCP. The optimum extraction for the ultrasound-assisted extraction of PCP were obtained as ratio of solvent to material 40 mL/g, ultrasonic power 380 W, and extraction time of 50 min. The yield of PCP reached 8.71% under these optimized conditions. PCP was further purified by using anion exchange chromatography and gel filtration, an acidic fraction PCP-AP-1 was hereby obtained. The results of structural elucidation indicated that PCP-AP-1 was a typical pectic polysaccharide with a molecular weight of 66360 Da, mainly composed of galacturonic acid (68.5 mol%), followed by arabinose (9.8 mol%), rhamnose (9.4 mol%), glucose (7.7 mol%), with homogalacturonan region and rhamnogalacturonan I regions. In vitro study showed that PCP-AP-1 could improve the inflammation induced by lipopolysaccharide in intestinal epithelial cells, which was probably performed through the inhibition of multiple signaling pathways including the inhibition of TLR4, NOD1/2 and NF-κB pathway, as well as the reduction of NLRP3 inflammasome. This study defined the type of polysaccharide present in P. chinense and revealed a potential of application this plant in the prevention of intestinal inflammatory diseases.

Penthorum chinense Pursh improves type 2 diabetes mellitus via modulating gut microbiota in db/db mice

Penthorum chinense Pursh (P. chinense) has been traditionally used as hepatoprotective food and medicine for hundreds of years due to its significant antioxidant and anti-inflammatory activities. However, the efficacy and mechanisms of action of P. chinense in type 2 diabetes mellitus were not fully understood. In this study, we found that P. chinense extract (PCP) supplementation resulted in reduced body weight and hyperglycemia, improved pancreatic tissue injury and insulin sensitivity, and decreased inflammatory cytokines expression in spontaneously diabetic db/db mice. 16S rRNA gene sequencing of fecal samples showed that PCP administration decreased the abundance of Firmicutes and increased the proportion of Bacteroidetes at the phylum level. Moreover, Muribaculum, Barnesiella, Prevotella, and Mucinivorans were enriched, with Desulfovibrio and Lactobacillus lowered at the genus level in db/db mice with PCP supplementation. These results suggested that PCP may ameliorate hyperglycemia, insulin resistance, and inflammation by remodeling the gut microbiota in db/db mice.

Oxidative stability and compositional characteristics of oil from microwave irradiated black cumin seed under accelerated oxidation condition

The present work evaluated the impact of microwave pre-treatment on the storage stability, fatty acids and triacylglycerol contents in black cumin seed oil (BCO) during storage at 62 ºC. During storage, the oxidative indicator values (free acidity, peroxide value, p-anisidine value, TOTOX, specific extinctions and thiobarbituric acid) for the oils increased faster in untreated oil samples than in the microwaved samples. The degradation rate of polyunsaturated fatty acids (PUFAs) and triacylglycerol species (LLL and OLL) during storage were higher in untreated samples compared to treated ones, indicating that oxidation proceeded more slowly in the treated samples. During storage, the generation of hydroperoxides, their degradation and the formation of secondary oxidation products as investigated by FTIR, were lower in the treated oils. In conclusion, microwave pre-treatment prior to oil extraction reduced the oxidative degradation of oil samples, thereby increasing the storage stability of BCO.

An Updated Review on Efficiency of Penthorum chinense Pursh in Traditional Uses, Toxicology, and Clinical Trials

Traditional Chinese medicines (TCM) play an important role in the control and treatment of several animal diseases. Penthorum chinense Pursh (PCP) is a famous plant for its use in traditional medication practice and therapeutic effects in numerous pathological conditions. In China, PCP is utilized for both food and medication due to numerous bioactivities. PCP is widely administered in prevention and treatment of traumatic injury, edema, and liver diseases with functions of reducing swelling, support diuresis, blood stasis, and mitigation symptoms of excessive alcohol intake. Recently, PCP highlighted for research trials in various fields including pharmacology, pharmacognosy, cosmeceuticals, nutraceuticals, and pharmaceuticals due to medicinal significance with less toxicity and an effective ethnomedicine in veterinary practice. PCP contains diverse important ingredients such as flavonoids, organic acids, coumarins, lignans, polyphenols, and sterols that are important bioactive constituents of PCP exerting the therapeutic benefits and organ-protecting effects. In veterinary, PCP extract, compound, and phytochemicals/biomolecules significantly reversed the liver and kidney injuries, via antioxidation, oxidative stress, apoptosis, mitochondrial signaling pathways, and related genes. PCP water extract and compounds also proved in animal and humans' clinical trial for their hepatoprotective, antiaging, nephroprotective, anti-inflammatory, antidiabetic, antibacterial, antiapoptotic, immune regulation, and antioxidative stress pathways. This updated review spotlighted the current information on efficiency and application of PCP by compiling and reviewing recent publications on animal research. In addition, this review discussed the toxicology, traditional use, comparative, and clinical application of PCP in veterinary practices to authenticate and find out new perspectives on the research and development of this herbal medicine.

Targeting microglial autophagic degradation of the NLRP3 inflammasome for identification of thonningianin A in Alzheimer’s disease

Background

NLRP3 inflammasome-mediated neuroinflammation plays a critical role in the pathogenesis and development of Alzheimer’s disease (AD). Microglial autophagic degradation not only decreases the deposits of extracellular Aβ fibrils but also inhibits the activation of NRLP3 inflammasome. Here, we aimed to identify the potent autophagy enhancers from Penthorum chinense Pursh (PCP) that alleviate the pathology of AD via inhibiting the NLRP3 inflammasome.

Methods

At first, autophagic activity-guided isolation was performed to identify the autophagy enhancers in PCP. Secondly, the autophagy effect was monitored by detecting LC3 protein expression using Western blotting and the average number of GFP-LC3 puncta per microglial cell using confocal microscopy. Then, the activation of NLRP3 inflammasome was measured by detecting the protein expression and transfected fluorescence intensity of NLRP3, ASC, and caspase-1, as well as the secretion of proinflammatory cytokines. Finally, the behavioral performance was evaluated by measuring the paralysis in C. elegans, and the cognitive function was tested by Morris water maze (MWM) in APP/PS1 mice.

Results

Four ellagitannin flavonoids, including pinocembrin-7-O-[4″,6″-hexahydroxydiphenoyl]-glucoside (PHG), pinocembrin-7-O-[3″-O-galloyl-4″,6″-hexahydroxydiphenoyl]-glucoside (PGHG), thonningianin A (TA), and thonningianin B (TB), were identified to be autophagy enhancers in PCP. Among these, TA exhibited the strongest autophagy induction effect, and the mechanistic study demonstrated that TA activated autophagy via the AMPK/ULK1 and Raf/MEK/ERK signaling pathways. In addition, TA effectively promoted the autophagic degradation of NLRP3 inflammasome in Aβ(1–42)-induced microglial cells and ameliorated neuronal damage via autophagy induction. In vivo, TA activated autophagy and improved behavioral symptoms in C. elegans. Furthermore, TA might penetrate the blood-brain barrier and could improve cognitive function and ameliorate the Aβ pathology and the NLRP3 inflammasome-mediated neuroinflammation via the AMPK/ULK1 and Raf/MEK/ERK signaling pathways in APP/PS1 mice.

Conclusion

We identified TA as a potent microglial autophagy enhancer in PCP that promotes the autophagic degradation of the NLRP3 inflammasome to alleviate the pathology of AD via the AMPK/ULK1 and Raf/MEK/ERK signaling pathways, which provides novel insights for TA in the treatment of AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41232-022-00209-7.

Integrated Chemical Interpretation and Network Pharmacology Analysis to Reveal the Anti-Liver Fibrosis Effect of Penthorum chinense

Liver fibrosis is a disease with complex pathological mechanisms. Penthorum chinense Pursh (P. chinense) is a traditional Chinese medicine (TCM) for liver injury treatment. However, the pharmacological mechanisms of P. chinense on liver fibrosis have not been investigated and clarified clearly. This study was designed to investigate the chemicals in P. chinense and explore its effect on liver fibrosis. First, we developed a highly efficient method, called DDA-assisted DIA, which can both broaden mass spectrometry (MS) coverage and MS² quality. In DDA-assisted DIA, data-dependent acquisition (DDA) and data-independent acquisition (DIA) were merged to construct a molecular network, in which 1,094 mass features were retained in Penthorum chinense Pursh (P. chinense). Out of these, 169 compounds were identified based on both MS¹ and MS² analysis. After that, based on a network pharmacology study, 94 bioactive compounds and 440 targets of P. chinense associated with liver fibrosis were obtained, forming a tight compound–target network. Meanwhile, the network pharmacology experimental results showed that multiple pathways interacted with the HIF-1 pathway, which was first identified involved in P. chinense. It could be observed that some proteins, such as TNF-α, Timp1, and HO-1, were involved in the HIF-1 pathway. Furthermore, the pharmacological effects of P. chinense on these proteins were verified by CCl₄-induced rat liver fibrosis, and P. chinense was found to improve liver functions through regulating TNF-α, Timp1, and HO-1 expressions. In summary, DDA-assisted DIA could provide more detailed compound information, which will help us to annotate the ingredients of TCM, and combination with computerized network pharmacology provided a theoretical basis for revealing the mechanism of P. chinense.

Antioxidant, Hypoglycemic and Molecular Docking Studies of Methanolic Extract, Fractions and Isolated Compounds from Aerial Parts of Cymbopogon citratus (DC.) Stapf

Traditionally, Cymbopogon citratus is used to treat a variety of ailments, including cough, indigestion, fever, and diabetes. The previous chemical and bioactive research on C. citratus mainly focused on its volatile oil. In this study, 20 non-volatile known compounds were isolated from the dried aerial part of C. citratus, and their structures were elucidated by MS, NMR spectroscopy, and comparison with the published spectroscopic data. Among them, 16 compounds were reported for the first time from this plant. The screening results for antioxidant and α-glucosidase inhibitory activities indicated that compounds caffeic acid (5), 1-O-p-coumaroyl-3-O-caffeoylglycerol (8), 1,3-O-dicaffeoylglycerol (9) and luteolin-7-O-β-D-glucopyranoside (12) had potent antioxidant capacities, with IC₅₀ values from 7.28 to 14.81 μM, 1.70 to 2.15 mol Trolox/mol and 1.31 to 2.42 mol Trolox/mol for DPPH, ABTS, and FRAP, respectively. Meanwhile, compounds 8 and 9 also exhibited significant inhibitory activities against α-glucosidase, with IC₅₀ values of 11.45 ± 1.82 μM and 5.46 ± 0.25 μM, respectively, which were reported for the first time for their α-glucosidase inhibitory activities. The molecular docking result provided a molecular comprehension of the interaction between compounds (8 and 9) and α-glucosidase. The significant antioxidant and α-glucosidase inhibitory activities of compounds 8 and 9 suggested that they could be developed into antidiabetic drugs because of their potential regulatory roles on oxidative stress and digestive enzyme.

Dihydrochalcones as antitumor agents

Dihydrochalcones are a class of secondary metabolites, possessing several biological properties such as antitumor, antioxidant, antibacterial, antidiabetic, estrogenic, anti-inflammatory, antithrombotic, antiviral, neuroprotective and immunomodulator properties; therefore, they are currently considered promising candidates in the drug discovery process. This review intend to debate their pharmacological actions with a particular attention to their antitumor activity against a panel of cancer cell-lines and to the description of the inhibition mechanisms of cell proliferation such as the regulation of angiogenesis, apoptosis, etc etc.

Nonselective Cell Necrosis Mediated by the Total Flavones of Penthorum Chinensis Pursh and Thonningianin-A in Human Hepatic and Hepatoma Cells

Penthorum chinensis Pursh (PCP), family Penthoraceae, has been used for hundreds of years in China. With the launch of PCP tablets, clinical applications focused on liver fibrosis and hepatocarcinoma. The purpose of this research was to explore the selectivity and toxicity of the active pharmacodynamic ingredients of PCP in vitro. The total flavones of PCP (TFPCE) and thonningianin-A (Th-A), a major flavone in TFPCE, were investigated on the cell death patterns in human hepatoma cells (HepG2) and human hepatic cells (LO2), followed by a concentration detection of LDH in the supernatants. Apoptosis and necrosis detection kits were used to validate the patterns of cell death caused by TFPCE and Th-A. Finally, the cytotoxicity of both TFPCE and Th-A were reproduced in the colorectal adenocarcinoma cells (NCI-H716). The results indicated that TFPCE inhibits the cell viability of HepG2 cells at a concentration lower than 25 μg/mL. Alternatively, the cell viability of LO2 cells dramatically decreased in the treatment of TFPCE at 25 μg/mL. The effects of Th-A on the cell viability of HepG2 cells and LO2 cells were consistent with TFPCE. LDH detection indicated that TFPCE and Th-A increased the LDH concentration of the supernatants in a dose-dependent way, indicating the pattern of cell necrosis. Fluorescence staining verified the necrosis cell death caused by TFPCE and Th-A. A dose-dependent tendency was obtained in NCI-H716 cells, indicating that the cell viability of NCI-H716 cells was significantly suppressed with the treatment of TFPCE and Th-A. Our results bring the potential toxicity of PCP to the forefront of public attention. Therefore, the clinical application of P chinensis is required to focus more on its cytotoxic effect.

Quantification of thonningianin a in rat plasma by liquid chromatography tandem mass spectrometry and its application to a pharmacokinetic study

CONTEXT

Thonningianin A is an ellagitannin substance and displays multiple pharmacological activities.

OBJECTIVE

This study investigated the pharmacokinetic characteristics of thonningianin A after oral administration in rats using a fully validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method.

MATERIALS AND METHODS

A sensitive and selective LC-MS/MS assay was developed for quantifying thonningianin A. Eighteen Wistar rats were randomly divided into three groups (n = 6), which were given at a single dose of 10, 20, or 40 mg/kg thonningianin A by gavage. Blood samples (200 µL) were collected from the orbit vein at designated time points and analyzed using the LC-MS/MS method to measure the levels of thonningianin A.

RESULTS

Thonningianin A and internal standard (IS) were eluted at 1.5 and ∼3.0 min, respectively. The selected reaction mode transitions monitored were m/z 873.2 > 300.3 and 819.3 > 610.6 for thonningianin A and the IS, respectively. The calibration range was 10-1200 ng/mL. The intra- and the inter-day accuracy and precision met the acceptance criteria. No carryover and matrix effect were observed. The plasma concentrations of thonningianin A increased rapidly after oral administration of three dosages and reached the mean peak concentrations (C_max) within 0.61-0.83 h. Meanwhile, AUC_0-t/AUC_0-∞ of the three dosage groups was more than 89.0% (10 mg/kg), 95.7% (20 mg/kg), and 97.0% (40 mg/kg).

DISCUSSION AND CONCLUSIONS

The present method is the first report in terms of the simple precipitation procedure, high sensitivity, and high-throughput efficiency. This validated assay was successfully applied to determine the pharmacokinetic behaviours of thonningianin A in rats. This study should be helpful for providing references for understanding the action mechanism and further application of Penthorum chinense.

Identification of neolignans with PCSK9 downregulatory and LDLR upregulatory activities from Penthorum chinense and the potential in cholesterol uptake by transcriptional regulation of LDLR via SREBP2

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense has been used in East Asia for the treatment of cholecystitis, infectious hepatitis, jaundice and to treat liver problems. Recent evidences provided the potential for the clinical use of P. chinense in the treatment of metabolic disease.

AIM OF THE STUDY

Based on the traditional use and recent evidences, we investigated the effects of constituents from P. chinense with modulation on proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein receptor (LDLR) expression, and the effect of the most active substance on cholesterol uptake, and genes relevant to lipid metabolism.

MATERIALS AND METHODS

The isolation of compounds from the BuOH-soluble extract of 80% methanol extract of P. chinense was conducted using chromatographic methods and the structures were established by interpreting spectroscopic data. Quantitative real time-PCR, and Western blot analysis were performed to monitor the regulatory activity on PCSK9 and LDLR expression. PCSK9-LDLR binding interaction was also tested. The cholesterol uptake in hepatocyte was measured using 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI)-labeled LDL cholesterol. Additionally, gene network analysis of LDLR and responses of its target proteins were carried out to discover genes germane to the effect of active compound on HepG2 cells. Moreover, we performed protein-protein interaction analysis via String and constructed the compound target network using Cytoscape.

RESULTS

Two new neolignans and 37 known compounds were characterized from P. chinense. Of the isolated compounds, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3), penthorin A (4) and methyl gallate (25) were found to suppress PCSK9 mRNA expression with IC₅₀ values of 5.13, 15.56 and 11.66 μM, respectively. However, all the isolated compounds were found to be inactive in PCSK9-LDLR interaction assay. Additionally, a dibenzoxepine-type lignan analog, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) demonstrated to upregulate LDLR mRNA and protein expression via transcriptional factor sterol regulatory element-binding protein 2 (SREBP2). Furthermore, (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) increase the LDL-cholesterol uptake in DiI-LDL assay.

CONCLUSION

(7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (3) seemed to increase potentially cholesterol uptake via the downregulation of PCSK9 and the activation of LDLR in hepatocytes. Moreover, SREBP2 was found to play an important role in regulation of PCSK9 and LDLR by (7'E,8S)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one.

Polyphenols from Penthorum chinense Pursh. Attenuates high glucose-induced vascular inflammation through directly interacting with Keap1 protein

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense Pursh is used for promoting diuresis and alleviating "heat"-associated disorders, which were considered to be related to diabetic in Traditional Chinese Medicine (TCM).

AIMS OF THIS STUDY

Here, we aimed to evaluate the ability and underlying mechanism of the ethyl acetate fraction of Penthorum chinense Pursh stems (PSE) to inhibit vascular inflammation in high glucose (HG)-induced human umbilical vein endothelial cells (HUVEC cells).

MATERIALS AND METHODS

HUVEC cells were pre-treated with PSE following HG treatment. The cell viability, mitochondrial membrane potential (MMP), lactate dehydrogenase (LDH) levels, reactive oxygen species (ROS) generation were analyzed. Inflammatory, and antioxidant,-related proteins were analyzed using western blotting. Molecular docking and drug affinity targeting experiments (DARTS) were utilized to analyze and verify the binding of the Keap1 protein and polyphenols of PSE.

RESULTS

HG can significantly increase the activity of lactic dehydrogenase (LDH), destroy the mitochondrial membrane potential (MMP), and promote the generation of reactive oxygen species (ROS), while PSE treatment reversed these changes. Mechanistically, PSE inhibited NF-κB and inflammatory cytokines activation induced by HG through activating the expression of Nrf2 and its downstream antioxidant proteins Heme oxygenase-1 (HO-1), NAD (P)H Quinone Dehydrogenase 1 (NQO1), Glutamate cysteine ligase catalytic subunit (GCLC), Glutamate-cysteine ligase modifier (GCLM). Further study indicated that PSE activated Nrf2 antioxidant pathway mainly by the binding of primary polyphenols from PSE and the Keap1 protein.

CONCLUSION

Taken together, the present data highlight the health benefits of polyphenols from Penthorum chinense Pursh. regarding diabetes, proving it to be an important source of health care products. Besides, binding of the Keap1 protein may be an effective strategy to activate Nrf2 antioxidant pathway and prevent diabetes.

An Overview of the Mechanism of Penthorum chinense Pursh on Alcoholic Fatty Liver

Alcohol liver disease (ALD) caused by excessive alcohol consumption is a progressive disease, and alcohol fatty liver disease is the primary stage. Currently, there is no approved drug for its treatment. Abstinence is the best way to heal, but patients' compliance is poor. Unlike other chronic diseases, alcohol fatty liver disease is not caused by nutritional deficiencies; it is caused by the molecular action of ingested alcohol and its metabolites. More and more studies have shown the potential of Penthorum chinense Pursh (PCP) in the clinical use of alcohol fatty liver treatment. The purpose of this paper is to reveal from the essence of PCP treatment of alcohol liver mechanism mainly by the ethanol dehydrogenase (ADH) and microsomal ethanol oxidation system-dependent cytochrome P4502E1 (CYP2E1) to exert antilipogenesis, antioxidant, anti-inflammatory, antiapoptotic, and autophagy effects, with special emphasis on its mechanisms related to SIRT1/AMPK, KEAP-1/Nrf2, and TLR4/NF-κB. Overall, data from the literature shows that PCP appears to be a promising hepatoprotective traditional Chinese medicine (TCM).

A review of Penthorum chinense Pursh for hepatoprotection: Traditional use, phytochemistry, pharmacology, toxicology and clinical trials

ETHNOPHARMACOLOGICAL RELEVANCE

In China, Penthorum chinense Pursh (P. chinense) has been used for hundreds of years traditionally for alleviating symptoms by excessive intake of alcohol as well as in the treatment of traumatic injury, edema and liver diseases. Recently, P. chinense and its extract have been developed into tea, drinks or medicines for treatment of liver diseases, including hepatic virus infections, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD) and liver fibrosis.

AIM OF THE STUDY

The main purpose of this review is to provide a critical appraisal of the existing knowledge on the phytochemical data, quality control aspect, pharmacological, as well as toxicological and clinical studies performed on P. chinense, including the identification of scientific gaps.

MATERIALS AND METHODS

A detailed literature search was conducted using various online search engines, such as Pubmed, Scopus, Google Scholar, Mendeley, Web of Science as well as China National Knowledge Infrastructure (CNKI) database.

RESULTS

In the pharmacological studies, there clearly are links between local/traditional uses and the biomedical investigations. Most pharmacological studies indicated potential liver protective effects in experimental models of chemicals-induced liver injury, acute and chronic alcoholic liver injury, NAFLD, liver fibrosis and viral infection, potentially through antioxidant effects, balancing key liver enzyme levels, inhibition of hepatic virus DNA replication, inhibition of hepatic stellate cells activation and inflammation either in vitro or in vivo. In some models, the effects of P. chinense is comparable with the one of silymarin. Clinical studies have suggested that P. chinense is safe and effective in treating several liver diseases, although most of them are not double-blinded and placebo-controlled studies. Toxicology studies show that P. chinense has no obvious toxicity or side effects in animals or human. Flavonoids, lignans, coumarins, polyphenols and organic acids have been identified. However, only a few studies have investigated the active compounds (mainly flavonoids and lignans) and molecular mechanisms of P. chinense.

CONCLUSION

P. chinense seems to be safe and shows relevant liver protecting effects. Therefore, it might be a promising candidate for developing as new hepatoprotective agents. However, a lack of understanding of the active compounds and mechanisms of action needs further attention.

Dihydrochalcones: Methods of Acquisition and Pharmacological Properties-A First Systematic Review

Dihydrochalcones are a class of secondary metabolites, for which demand in biological and pharmacological applications is still growing. They posses several health-endorsing properties and, therefore, are promising candidates for further research and development. However, low content of dihydrochalcones in plants along with their low solubility and bioavailability restrict the development of these compounds as clinical therapeutics. Therefore, chemomicrobial and enzymatic modifications are required to expand their application. This review aims at analyzing and summarizing the methods of obtaining dihydrochalcones and of presenting their pharmacological actions that have been described in the literature to support potential future development of this group of compounds as novel therapeutic drugs. We have also performed an evaluation of the available literature on beneficial effects of dihydrochalcones with potent antioxidant activity and multifactorial pharmacological effects, including antidiabetic, antitumor, lipometabolism regulating, antioxidant, anti-inflammatory, antibacterial, antiviral, and immunomodulatory ones. In addition, we provide useful information on their properties, sources, and usefulness in medicinal chemistry.

Bioactivity Evaluation of Pinocembrin Derivatives From Penthorum chinense Pursh Stems

The extract of Penthorum chinense Pursh (PCP), a well-known Miao herb medicine, has been used as a key component for a Chinese patented drug to treat several kinds of liver-related diseases. In this work, 3 pinocembrin derivatives, S1, S2, and S3, were isolated from PCP stems and identified with high-performance liquid chromatography and electrospray ionization mass spectrometer. The molecular masses of S1, S2, and S3 were identical to Pinocembrin-7-O-[4″,6″-hexahydroxydiphenoyl (HHDP)]-β-D-glucose, Pinocembrin-7-O-[3″-O-galloyl-4″,6″-(s)-HHDP)-β-D-glucose, and Thonningianin A, respectively. Their free radical scavenging capability was evaluated with the 2,2-diphenyl-1-picrylhydrazyl assay. The half-maximal effective concentrations of S1, S2, and S3 were 26.75, 9.06, and 5.50 μg/mL, respectively. In vitro AML-12 assays demonstrated that S1 (5-20 μg/mL), S2 (10-40 μg/mL), and S3 (10-40 μg/mL) not only protected cells from H2O2-induced oxidation and alcohol-induced cell damages, but also reduced oleic acid (OA)-induced triglyceride accumulations in a dose-dependent manner. However, the 3 compounds potently exhibited similar cytotoxicity effect at high concentrations. The half-maximal inhibitory concentrations of S1, S2, and S3 to AML-12 cells were 74.19, 85.86, and 80.43 μg/mL. In addition, the 3 compounds also showed antibacterial activity on Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Lactobacillus rhamnosus, and Bacillus subtilis.

Characterization of the anti-Staphylococcus aureus fraction from Penthorum chinense Pursh stems

Background

Methicillin-resistant Staphylococcus aureus (MRSA) causes serious infections in hospitals. Penthorum chinense Pursh (PCP), employed by the Miao ethnic minority in China, presents antibacterial activities. In this study, the anti-Staphylococcus aureus activities in the pinocembrin-7-O residue-rich fraction from PCP (PGF) were evaluated and characterized.

Methods

The PGF was prepared with 70% ethanol reflux extraction followed by fractional extraction and column chromatography. Pinocembrin-7-O residue components were identified with electrospray ionization mass spectrometry (ESI-MS). Anti-S. aureus activities of the fraction and the main components were evaluated in vitro with serially diluted microbroth assays. Cytotoxicity was evaluated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) chromogenic assays using the NCTC 1469 cell line.

Results

This study indicated that the PGF and three components (S1, S2, and S3) presented anti-S. aureus activities, including against clinically isolated MRSA strains. The molecular masses of S1, S2, and S3 were identical to those of pinocembrin-7-O-[4″,6″-hexahydroxydiphenoyl (HHDP)]-β-D-glucose, pinocembrin-7-O-[3″-O-galloyl-4″,6″-(s)-HHDP]-β-D-glucose, and Thonningianin A, respectively. The PGF, S1, S2, and S3 all presented an identical minimum inhibitory concentration (MIC) against S. aureus ATCC 25923 and ATCC 43300, which was 62.5 μg/mL. The minimum bactericidal concentrations (MBCs) of the PGF and S3 against ATCC 25923 were 125 and 250 μg/mL, and the MBCs of the PGF, S2, and S3 against ATCC 43300 were 250, 500, and 250 μg/mL, respectively. A time-kill assay consistently indicated that none of the bacterial clones of ATCC 25923 and ATCC 43300 could survive under 2× and 4× MIC PGF treatment for 24 h, respectively. In contrast, 10⁴ CFU (colony-forming units) of ATCC 25923 and ATCC 43300 were killed by 8× and 4× MIC S3 within 24 h, respectively. Additionally, 1×, 2×, and 4× MIC the PGF presented similar postantibiotic effects (PAEs) on the strain ATCC 25923. However, the PAE of the PGF on the strain ATCC 43300 was concentration dependent (1× < 2× < 4× MIC). Finally, the PGF (200 μg/mL) and S3 (60 μg/mL) showed no cytotoxicity against human hepatoma cells.

Conclusions

The PGF and S3 from PCP present potential for the treatment of S. aureus and MRSA infections. The components S1 and S2 present inhibition activities against S. aureus.

Progress in the discovery of naturally occurring anti-diabetic drugs and in the identification of their molecular targets

Diabetes mellitus (DM), a chronic metabolic disease, severely affects patients' life and intensively increases risks of developing other diseases. It is estimated that 0.4 billion individuals worldwide are subjected to diabetes, especially type 2 diabetes mellitus. At present, although various synthetic drugs for diabetes such as Alogliptin and Rosiglitazone, etc. have been used to manage diabetes, some of them showed severe side effects. Given that the pathogenesis of type 2 diabetes mellitus, natural occurring drugs are beneficial alternatives for diabetes therapy with low adverse effects or toxicity. Recently, more and more plant-derived extracts or compounds were evaluated to have anti-diabetic activities. Their anti-diabetic mechanisms involve certain key targets like α-glucosidase, α-amylase, DPP-4, PPAR γ, PTP1B, and GLUT4, etc. Here, we summarize the newly found anti-diabetic (type 2 diabetes mellitus) natural compounds and extracts from 2011-2017, and give the identification of their molecular targets. This review could provide references for the research of natural agents curing type 2 diabetes mellitus (T2DM).

Enzymatic Extraction, Purification, and Characterization of Polysaccharides from Penthorum chinense Pursh: Natural Antioxidant and Anti-Inflammatory

Penthorum chinense Pursh (PCP) is a kind of functional food or medicine for liver protection. In the present work, Plackett-Burman design, steepest ascent method, and response surface methodology (RSM) were employed to obtain maximum total sugar yield. The experimental yield of 6.91% indicated a close agreement with the predicted yield of 7.00% of the model under optimized conditions. The major polysaccharide fraction (PCPP-1a) from PCPP was purified and identified as acidic polysaccharides with a high content of uronic acid (FT-IR, UV, HPGPC). PCPP had similar monosaccharide profile with PCPP-1a but was rich in galacturonic acid (HPLC). Both of PCPP and PCPP-1a possessed strong hydroxyl radical scavenging, DPPH radical scavenging, and Fe²⁺ chelating activities. Moreover, they were revealed to show strong anti-inflammatory activities by inhibiting NO, TNF-α, and IL-1β release compared to LPS treatment in RAW264.7 cells. These data suggest that the polysaccharides from PCP could be potential natural products for treating ROS and inflammatory-related diseases.

Comparative investigation for hypoglycemic effects of polysaccharides from four substitutes of Lonicera japonica in Chinese medicine

The polysaccharide fractions were obtained from flower buds of the four substitutes of Lonicera japonica, L. macranthoides (LMPB), L. hypoglauca (LHPB), L. fulvotomentosa (LFPB) and L. confuse (LCPB), and their hypoglycemic effects were investigated. In study, streptozocin (STZ)-induced diabetic rats were orally administrated once daily with LMPB, LHPB, LFPB and LCPB (each 800 mg/kg) for 42 days. Reduction for food and water intake (p < 0.05, p < 0.01) and levels of sugar and insulin (p < 0.01, p < 0.05) in blood, as well as elevation for contents of liver and skeletal muscle glycogen (p < 0.05) and concentrations of hepatic pyruvate kinase and hexokinase (p < 0.01, p < 0.05) were observed. Together with significant decline of total cholesterol (TC, 45.8 51.0%, p < 0.05), total triglyceride (TG, 50.6-53.8%, p < 0.01), low-density lipoprotein-cholesterin (LDL-C, 71.2-76.3%, p < 0.01) and very-low-density lipoprotein-cholesterin (VLDL-C, 45.2-50.0%, p < 0.01), the significant rise of high-density lipoprotein-cholesterin (HDL-C, 21.6-24.3%, p < 0.05) were also demonstrated. Consequently, the four polysaccharide fractions displayed notable hypoglycemic effects, similar to that of the polysaccharide fraction from L. japonica (LJP), so that they can be also considered as ingredients of functional foods for type-2 diabetes mellitus (T2DM).

Quality assessment of Penthorum chinense Pursh through multicomponent qualification and fingerprint, chemometric, and antihepatocarcinoma analyses

An efficient method combined with fingerprint and chemometric analyses was developed to evaluate the quality of Penthorum chinense Pursh.

A Protein Isolate from Moringa oleifera Leaves Has Hypoglycemic and Antioxidant Effects in Alloxan-Induced Diabetic Mice

Moringa oleifera has been used in traditional medicine to treat diabetes. However, few studies have been conducted to relate its antidiabetic properties to proteins. In this study, a leaf protein isolate was obtained from M. oleifera leaves, named Mo-LPI, and the hypoglycemic and antioxidant effects on alloxan-induced diabetic mice were assessed. Mo-LPI was obtained by aqueous extraction, ammonium sulphate precipitation and dialysis. The electrophoresis profile and proteolytic hydrolysis confirmed its protein nature. Mo-LPI showed hemagglutinating activity, cross-reaction with anti-insulin antibodies and precipitation after zinc addition. Single-dose intraperitoneal (i.p.) administration of Mo-LPI (500 mg/kg·bw) reduced the blood glucose level (reductions of 34.3%, 60.9% and 66.4% after 1, 3 and 5 h, respectively). The effect of Mo-LPI was also evidenced in the repeated dose test with a 56.2% reduction in the blood glucose level on the 7th day after i.p. administration. Mo-LPI did not stimulate insulin secretion in diabetic mice. Mo-LPI was also effective in reducing the oxidative stress in diabetic mice by a decrease in malondialdehyde level and increase in catalase activity. Mo-LPI (2500 mg/kg·bw) did not cause acute toxicity to mice. Mo-LPI is a promising alternative or complementary agent to treat diabetes.

Evaluation of Hypoglycemic and Genotoxic Effect of Polyphenolic Bark Extract from Quercus sideroxyla

Quercus sideroxyla is a wood species whose bark has phenolic compound and should be considered to be bioactive; the hypoglycemic and genotoxic properties of Q. sideroxyla bark were evaluated in this study. Total phenolic compound was determined in crude extract (CE) and organic extract (OE). The OE has the highest amount of phenols (724.1 ± 12.0 GAE/g). Besides, both CE and OE demonstrated effect over the inhibition of α-amylase in vitro. Hypoglycemic activity was assessed by glucose tolerance curve and the area under curve (UAC); OE showed the highest hypoglycemic activity. In addition, diabetes was induced by streptozotocin (65 mg/kg) and the extracts (50 mg/kg) were administered for 10 days; OE showed hypoglycemic effect compared with diabetic control and decreased hepatic lipid peroxidation. Acute toxicity and genotoxicity were evaluated in CE; results of acute toxicity did not show any mortality. Besides, the comet assay showed that CE at a dose of 100 mg/kg did not show any genotoxic effect when evaluated at 24 h, whereas it induced slight damage at 200 mg/kg, with the formation of type 1 comets.

Antidiabetic, antihyperlipidaemic, and antioxidant activity of Syzygium densiflorum fruits in streptozotocin and nicotinamide-induced diabetic rats

Context Syzygium densiflorum Wall. ex Wight & Arn (Myrtaceae) has been traditionally used by local tribes of the Nilgiris, Tamil Nadu, India, for the treatment of diabetes, however, no definitive experimental studies are available. Objective This study investigates the antidiabetic, antihyperlipidaemic and antioxidant activities of ethanol extract of S. densiflorum (EFSD) fruits in streptozotocin (STZ) and nicotinamide (NA)-induced diabetic rats. Materials and methods Acute oral toxicity and oral glucose tolerance were assessed in normal rats. The antidiabetic, antihyperlipidaemic and antioxidant activities were investigated in STZ - NA-induced diabetic rats. Diabetic rats were orally administered with glibenclamide (10 mg/kg b.wt), EFSD (200, 400 and 800 mg/kg b.wt) for 28 d. Further, changes in the blood glucose level (BGL), biochemical parameters, antioxidants were observed and histology of pancreas was performed. Results No toxicity and lethality were observed. Results of the following parameters are represented by treated versus disease control (STZ + NA) groups. BGL (161.33 ± 22.8 versus 476.17 ± 56.58 mg/dl), glycosylated haemoglobin (5.285 ± 0.19 versus 8.05 ± 0.55%), urea (40.32 ± 1.96 versus 75.37 ± 2.91 mg/dl), uric acid (1.2 ± 0.07 versus 2.16 ± 0.05 mg/dl), total cholesterol (89.3 ± 5.14 versus 139.7 ± 5.95 mg/dl) and triglycerides (79.65 ± 2.52 versus 108.9 ± 3.61 mg/dl) were significantly decreased, whereas haemoglobin (11.75 ± 0.73 versus 7.95 ± 0.42 g/dl), high-density lipoprotein cholesterol (14.2 ± 1.11 versus 6.97 ± 0.84 mg/dl), total protein (45%) and liver glycogen (87%) were significantly increased in EFSD-treated diabetic group. Significant changes were observed in the enzymatic and non-enzymatic antioxidants in EFSD-treated groups (p < 0.001). Histopathological examination showed the regeneration of β-cells in Islets of Langerhans. Conclusion This study confirms the antidiabetic, antihyperlipidaemic and antioxidant activities of S. densiflorum fruits.

Chemical and Biological Aspects of Extracts from Medicinal Plants with Antidiabetic Effects

Diabetes mellitus is a chronic disease and a leading cause of death in western countries. Despite advancements in the clinical management of the disease, it is not possible to control the late complications of diabetes. The main characteristic feature of diabetes is hyperglycemia, which reflects the deterioration in the use of glucose due to a faulty or poor response to insulin secretion. Alloxan and streptozotocin (STZ) are the chemical tools that are most commonly used to study the disease in rodents. Many plant species have been used in ethnopharmacology or to treat experimentally symptoms of this disease. When evaluated pharmacologically, most of the plants employed as antidiabetic substances have been shown to exhibit hypoglycemic and antihyperglycemic activities, and to contain chemical constituents that may be used as new antidiabetic agents. There are many substances extracted from plants that offer antidiabetic potential, whereas others may result in hypoglycemia as a side effect due to their toxicity, particularly their hepatotoxicity. In this article we present an updated overview of the studies on extracts from medicinal plants, relating the mechanisms of action by which these substances act and the natural principles of antidiabetic activity.