Platycodin D protects acetaminophen-induced hepatotoxicity by inhibiting hepatocyte MAPK pathway and apoptosis in C57BL/6J mice

A novel approach to alleviate acetaminophen-induced hepatotoxicity with hybrid balloon flower root-derived exosome-like nanoparticles (BDEs) with silymarin via inhibition of hepatocyte MAPK pathway and apoptosis

INTRODUCTION

Balloon flower root-derived exosome-like nanoparticles (BDEs) have recently been proposed as physiologically active molecules with no cytotoxicity. However, the therapeutic effects of drug-induced hepatotoxicity of BDEs have not been elucidated. BDEs contain a large amount of platycodin D, which is widely known to be effective in regulating inflammation and ameliorating systemic toxicity. Thus, the main therapeutic activity of BDEs is attributed to inhibiting the inflammatory response and alleviating toxicity. In this study, we fabricated the hybrid BDEs fused with liposomes containing silymarin (SM) to enhance the synergistic effect on inhibition of acetaminophen-induced hepatotoxicity (APAP).

OBJECTIVE

Considering the potential therapeutic effects of BDEs, and the potential to achieve synergistic effects to improve therapeutic outcomes, we constructed hybrid BDEs with a soy lecithin-based liposome loaded with SM. Since liposomes can provide higher thermal stability and have greater structural integrity, these might be more resistant to clearance and enzymatic degradation of drug molecules.

METHODS

Hybrid BDEs with liposome-loaded SM (BDEs@lipo-SM) were fabricated by thin-film hydration and extrusion. BDEs@lipo-SM were characterized using dynamic light scattering and high-performance liquid chromatography. After confirmation of the physical properties of BDEs@lipo-SM, various therapeutic properties were evaluated.

RESULTS

BDEs@lipo-SM were internalized by hepatocytes and immune cells and significantly decreased mRNA expression of apoptosis and inflammation-relevant cytokines by inhibiting the hepatocyte MAPK pathway. BDEs@lipo-SM significantly induced an increase in glutathione levels and inhibited APAP-induced hepatotoxicity.

CONCLUSION

From this study, we know that BDEs are reliable and safe nanovesicles containing natural metabolites derived from balloon flower, and they can facilitate intercellular communication. BDEs are also easily modified to enhance drug loading capacity, targeting effects, and long-term accumulation in vivo. BDEs@lipo-SM have therapeutic benefits for acute liver injury and can alleviate cell death and toxicity. They can be efficiently delivered to the liver and effectively inhibit APAP-induced hepatotoxicity by inhibiting the MAPK signaling pathway and apoptosis, which accelerates liver recovery in the APAP-induced acute liver injury model. These findings highlight that BDEs represent an attractive delivery vehicle for drug delivery.

Platycodin D represses β-catenin to suppress metastasis of cetuximab-treated KRAS wild-type colorectal cancer cells

Cetuximab, an epidermal growth factor receptor (EGFR) inhibitor, is extensively used for clinical therapy in KRAS wild-type colorectal cancer (CRC) patients. However, some patients still cannot get benefit from the therapy, because metastasis and resistance occur frequently after cetuximab treatment. New adjunctive therapy is urgently needed to suppress metastasis of cetuximab-treated CRC cells. In this study, we used two KRAS wild-type CRC cells, HT29 and CaCo2, to investigate whether platycodin D, a triterpenoid saponin isolated from Chinese medicinal herb Platycodon grandifloras, is able to suppress the metastasis of cetuximab-treated CRC. Label-free quantitative proteomics analyses showed that platycodin D but not cetuximab significantly inhibited expression of β-catenin in both CRC cells, and suggested that platycodin D counteracted the inhibition effect of cetuximab on cell adherence and functioned in repressing cell migration and invasion. Western blot results showed that single platycodin D treatment or combined platycodin D and cetuximab enhanced inhibition effects on expressions of key genes in Wnt/β-catenin signaling pathway, including β-catenin, c-Myc, Cyclin D1 and MMP-7, compared to single cetuximab treatment. Scratch wound-healing and transwell assays showed that platycodin D combined with cetuximab suppressed migration and invasion of CRC cells, respectively. Pulmonary metastasis model of HT29 and CaCo2 in nu/nu nude mice consistently showed that combined treatment using platycodin D and cetuximab inhibited metastasis significantly in vivo. Our findings provide a potential strategy to inhibit CRC metastasis during cetuximab therapy by addition of platycodin D.

Temporal analysis of paracetamol-induced hepatotoxicity

Paracetamol-induced hepatotoxicity (APAP) causes severe damage that may be irreversible. Understanding the evolution of liver injury caused by overdose of the drug is important to assist in the treatment. In the present study, we evaluated the acute intoxication by APAP (500 mg/kg) in periods of 3 and 12 hours in C57BL/6 mice through biochemical, histological, inflammatory parameters, and the redox status. The results showed that in the 3-hour period there was an increase in creatinine dosage and lipid peroxidation (TBARS) compared to the control group. In the period of 12 hours after APAP intoxication all parameters evaluated were altered; there was an increase of ALT, AST, and necrosis, besides the increase of redox status biomarkers as carbonylated protein, TBARS, and MMP-9. We also observed activation of the inflammasome pathway as well as a reduction in the regenerative capacity of hepatocytes with a decrease in binucleated liver cells. In cytochrome gene expression, the mRNA level increased in CYP2E1 isoenzyme and reduced CYP1A2 expression. This study indicated that early treatment is necessary to mitigate APAP-induced acute liver injury, and alternative therapies capable of controlling the progression of intoxication in the liver are needed.

The Wu-Shi-Cha formula protects against ulcerative colitis by orchestrating immunity and microbiota homeostasis

ETHNOPHARMACOLOGICAL RELEVANCE

Ulcerative colitis (UC) has become a healthy burden worldwide due to its insidious onset and repetitive relapse, with a rather complex etiology, including inappropriate immune response, dysbiosis, genetic susceptibility, and unhealthy diets. The Wu-Shi-Cha (WSC) formula is a widely utilized drug to protect against gastrointestinal disorders.

AIM OF THE STUDY

The study aspired to dissect the pertinent mechanisms of the WSC to treat UC.

MATERIALS AND METHODS

Network pharmacology and weighted gene co-expression network analysis (WGCNA) were performed to predict the targets of WSC in the context of UC and colorectal cancer. Dextran sodium sulfate (DSS) was used to construct murine models of experimental colitis, and the WSC was given to colitis mice for 14 days. Feces and colon samples were subjected to 16S rRNA gene sequencing combined with liquid chromatography-mass spectrometry (LC-MS) and biochemical experiments, respectively.

RESULTS

Network pharmacology analysis predicted that the WSC formula could orchestrate inflammation, infection, and tumorigenesis, and WGCNA based on The Cancer Genome Atlas (TCGA) database showed a potent anti-neoplastic effect of the WSC therapy for colorectal cancer. The WSC therapy rescued bursts of pro-inflammatory cytokines and colonic epithelial collapse in DSS-induced colitis mice. Moreover, the high dose of WSC treatment facilitated the alternative activation of peritoneal macrophages (Mφs) and these Mφs were conducive to the survival of intestinal stem cells (ISCs), and the disturbed homeostasis of gut microbiota was re-established after WSC treatment, as evidenced by the decreased colonization of pathological taxa in the fecal samples.

CONCLUSION

The WSC formula suppresses inflammation and re-establishes the homeostasis of gut microbiota, thereby ameliorating colitis progression.

Platycodin D induces neutrophil apoptosis by downregulating PD-L1 expression to inhibit breast cancer pulmonary metastasis

During breast cancer development, programmed cell death 1 ligand 1 (PD-L1) overexpression in neutrophils leads to delayed apoptosis and promotes neutrophil hyperproliferation in the lung to form a premetastatic niche, which is beneficial for pulmonary metastasis. Platycodin D (PlaD), a triterpenoid saponin with known anti-inflammatory and antitumor effects, has been reported to downregulate PD-L1 expression. This study aimed to investigate the inhibitory effect of PlaD on neutrophil PD-L1 in 4 T1 tumor-bearing mice and the potential mechanism of breast cancer pulmonary metastasis. In this study, the orthotopic 4 T1 murine mammary carcinoma model was administered 10 and 20 mg/kg PlaD by gavage. PlaD reduced the excess neutrophils and decreased their high migratory capacity in bone marrow, peripheral blood and lung tissue in the premetastatic period, thereby effectively inhibiting tumor growth and pulmonary metastasis. Moreover, PlaD inhibited the phosphatidylinositol-3-kinase (PI3K)/Akt pathway by decreasing the expression of PD-L1 in neutrophils and promoted neutrophil apoptosis. In vitro, PlaD treatment decreased the viability and inhibited migration of neutrophil-like dHL-60 in a dose-dependent manner. Similarly, PlaD inhibited the increase in PD-L1 induced by IFN-γ stimulation and subsequently induced apoptosis in dHL-60 cells. In conclusion, the administration of PlaD inhibited the PI3K/Akt signaling pathway by reducing the expression of PD-L1 in neutrophils. PlaD promoted neutrophil apoptosis, thereby inhibiting the establishment of a premetastatic niche and ultimately blocking the development of pulmonary metastasis.

Biotransformation of Platycosides, Saponins from Balloon Flower Root, into Bioactive Deglycosylated Platycosides

Platycosides, saponins from balloon flower root (Platycodi radix), have diverse health benefits, such as antioxidant, anti-inflammatory, anti-tussive, anti-cancer, anti-obesity, anti-diabetes, and whitening activities. Deglycosylated platycosides, which show greater biological effects than glycosylated platycosides, are produced by the hydrolysis of glycoside moieties in glycosylated platycosides. In this review, platycosides are classified according to the chemical structures of the aglycone sapogenins and also divided into natural platycosides, including major, minor, and rare platycosides, depending on the content in Platycodi radix extract and biotransformed platycosides. The biological activities of platycosides are summarized and methods for deglycosylation of saponins, including physical, chemical, and biological methods, are introduced. The biotransformation of glycosylated platycosides into deglycosylated platycosides was described based on the hydrolytic pathways of glycosides, substrate specificity of glycosidases, and specific productivities of deglycosylated platycosides. Methods for producing diverse and/or new deglycosylated platycosides are also proposed.

Transcriptome-wide identification of WRKY transcription factors and their expression profiles in response to methyl jasmonate in Platycodon grandiflorus

Platycodon grandiflorus, a perennial flowering plant widely distributed in China and South Korea, is an excellent resource for both food and medicine. The main active compounds of P. grandiflorus are triterpenoid saponins. WRKY transcription factors (TFs) are among the largest gene families in plants and play an important role in regulating plant terpenoid accumulation, physiological metabolism, and stress response. Numerous studies have been reported on other medicinal plants; however, little is known about WRKY genes in P. grandiflorus. In this study, 27 PgWRKYs were identified in the P. grandiflorus transcriptome. Phylogenetic analysis showed that PgWRKY genes were clustered into three main groups and five subgroups. Transcriptome analysis showed that the PgWRKY gene expression patterns in different tissues differed between those in Tongcheng City (Southern Anhui) and Taihe County (Northern Anhui). Gene expression analysis based on RNA sequencing and qRT-PCR analysis showed that most PgWRKY genes were expressed after induction with methyl jasmonate (MeJA). Co-expressing PgWRKY genes with triterpenoid biosynthesis pathway genes revealed four PgWRKY genes that may have functions in triterpenoid biosynthesis. Additionally, functional annotation and protein-protein interaction analysis of PgWRKY proteins were performed to predict their roles in potential regulatory networks. Thus, we systematically analyzed the structure, evolution, and expression patterns of PgWRKY genes to provide an important theoretical basis for further exploring the molecular basis and regulatory mechanism of WRKY TFs in triterpenoid biosynthesis.

Platycodon grandiflorum (Jacq.) A. DC.: A review of phytochemistry, pharmacology, toxicology and traditional use

BACKGROUND

The traditional Chinese medicine Platycodon grandiflorum (Jacq.) A. DC. (PG, balloon flower) has medicinal and culinary value. It consists of a variety of chemical components including triterpenoid saponins, polysaccharides, flavonoids, polyphenols, polyethylene glycols, volatile oils and mineral components, which have medicinal and edible value.

PURPOSE

The ultimate goal of this review is to summarize the phytochemistry, pharmacological activities, safety and uses of PG in local and traditional medicine.

METHODS

A comprehensive search of published literature up to March 2022 was conducted using the PubMed, China Knowledge Network and Web of Science databases to identify original research related to PG, its active ingredients and pharmacological activities.

RESULTS

Triterpene saponins are the primary bioactive compounds of PG. To date, 76 triterpene saponin compounds have been isolated and identified from PG. In addition, there are other biological components, such as flavonoids, polyacetylene and phenolic acids. These extracts possess antitussive, immunostimulatory, anti-inflammatory, antioxidant, antitumor, antiobesity, antidepressant, and cardiovascular system activities. The mechanisms of expression of these pharmacological effects include inhibition of the expression of proteins such as MDM and p53, inhibition of the activation of enzymes, such as AKT, the secretion of inflammatory factors, such as IFN-γ, TNF-α, IL-2 and IL-1β, and activation of the AMPK pathway.

CONCLUSION

This review summarizes the chemical composition, pharmacological activities, molecular mechanism, toxicity and uses of PG in local and traditional medicine over the last 12 years. PG contains a wide range of chemical components, among which triterpene saponins, especially platycoside D (PD), play a strong role in pharmacological activity, representing a natural phytomedicine with low toxicity that has applications in food, animal feed and cosmetics. Therefore, PG has value for exploitation and is an excellent choice for treating various diseases.

Protective Effects of Platycodin D3 on Airway Remodeling and Inflammation via Modulating MAPK/NF-κB Signaling Pathway in Asthma Mice

Background

Asthma is a disease with airway hyperresponsive and airway inflammation. Platycodin D is a triterpenoid saponin extracted from Platycodon grandiflorus root, which has various pharmacological activities. The study mainly explored the effects of platycodin D3 (PD₃) in airway remodeling and inflammation of asthma.

Methods

The ovalbumin (OVA)-induced asthma mice were given PD3 (20 mg/kg, 40 mg/kg, and 80 mg/kg) in different groups. The asthma mice administrated with dexamethasone (DXM) were enrolled as the positive control group, and the normal control mice and asthma model mice separately received the same volume of saline. Mouse airway lung dynamic compliance (Cdyn) and total airway resistance (RL) were measured by the EMKA animal lung function analysis system. The inflammation factor levels were estimated by ELISA. Histopathological changes were tested by HE and PAS staining. The protein and phosphorylation levels of NF-κBp65, p38, ERK1/2, and JNK1/2 were detected by Western blot.

Results

In asthmatic mice, PD3 enhanced the airway Cdyn and decreased RL to improve the airway hyperreactivity and alleviated the pathological injury of lung tissues. In addition, PD3 could reduce the infiltration of inflammatory cells in BALF and suppress the levels of eotaxin, IL-4, IL-5, IL-13, IFN-γ, and IgE. Furthermore, PD3 treatment inhibited the phosphorylation of NF-κBp65, p38, ERK1/2, and JNK1/2 proteins in asthma mice.

Conclusion

PD3 treatment alleviated the airway remodeling and inflammation in asthmatic mice, which might be related to downregulating the phosphorylated proteins in the MAPK/NF-κB signaling pathway.

Integrated metabolomic and transcriptomic analysis reveals variation in the metabolites and genes of Platycodon grandiflorus roots from different regions

INTRODUCTION

Platycodon grandiflorum root (PG), a popular traditional Chinese medicine, contains considerable chemical components with broad pharmacological activities. The complexity and diversity of the chemical components of PG from different origins contribute to its broad biological activities. The quality of southern PG is superior to that of northern PG, but the mechanisms underlying these differences remain unclear.

OBJECTIVES

In order to study variation in the differentially accumulated metabolites (DAMs), differentially expressed genes (DEGs), as well as their interactions and signalling pathways among PG from Anhui and Liaoning.

METHODS

The metabolomes based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the transcriptome based on high-throughput sequencing technology were combined to comprehensively analyse PGn and PGb.

RESULTS

A total of 6515 DEGs and 83 DAMs from the comparison of PG from Anhui and Liaoning were detected. Integrated analysis of metabolomic and transcriptomic data revealed that 215 DEGs and 57 DAMs were significantly enriched in 48 pathways according to KEGG pathway enrichment analysis, and 15 DEGs and 10 DAMs significantly enriched in the main pathway sesquiterpenoid and triterpenoid and phenylpropanoid biosynthesis might play a key role in complex response or regulatory processes.

CONCLUSION

Differences in PG from southern and northern China might thus stem from differences in environmental factors, such as precipitation, light duration, and humidity. The results of our study provide new insight into geographic variation in gene expression and metabolite accumulation and will enhance the utilisation of PG resources.

In addition to its endosomal escape effect, platycodin D also synergizes with ribosomal inactivation protein to induce apoptosis in hepatoma cells through AKT and MAPK signaling pathways

Efficient endosomal escape after cellular uptake is a major challenge for the clinical application of therapeutic proteins. To overcome this obstacle, several strategies have been used to help protein drugs escape from endosomes without affecting the integrity of the cell membrane. Among them, some triterpenoid saponins with special structures were used to greatly enhance the anti-tumor therapeutic effect of protein toxins. Herein, we demonstrated that platycodin D (PD), polygalacin D (PGD) and platycodin D2 (PD2) from Platycodonis Radix significantly enhanced the ability of MHBP (a type I ribosome-inactivating protein toxin MAP30 fused with a cell-penetrating peptide HBP) to induce apoptosis in hepatoma cells. Based on the results of co-localization of endocytosed EGFP-HBP with a lysosomal probe and Galectin-9 vesicle membrane damage sensor, we demonstrated that PD, PGD and PD2 have the ability to promote endosomal escape of endocytic proteins without affecting the integrity of the plasma membrane. Meanwhile, we observed that cholesterol metabolism plays an important role in the activity of PD by RNA-seq analysis and KEGG pathway enrichment analysis, and confirm that PD, PGD and PD2 enhance the anti-tumor activity of MHBP by inducing the redistribution of free cholesterol and inhibiting the activity of cathepsin B and cathepsin D. Finally, we found that PD synergized with MHBP to induce caspase-dependent apoptosis through inhibiting Akt and ERK1/2 signaling pathways and activating JNK and p38 MAPK signaling pathways. This study provides new insights into the application of PD in cancer therapy and provides efficient and promising strategies for the cytosolic delivery of therapeutic proteins.

Molecular pathogenesis of acetaminophen-induced liver injury and its treatment options

Acetaminophen, also known as N-acetyl-p-aminophenol (APAP), is commonly used as an antipyretic and analgesic agent. APAP overdose can induce hepatic toxicity, known as acetaminophen-induced liver injury (AILI). However, therapeutic doses of APAP can also induce AILI in patients with excessive alcohol intake or who are fasting. Hence, there is a need to understand the potential pathological mechanisms underlying AILI. In this review, we summarize three main mechanisms involved in the pathogenesis of AILI: hepatocyte necrosis, sterile inflammation, and hepatocyte regeneration. The relevant factors are elucidated and discussed. For instance, N-acetyl-p-benzoquinone imine (NAPQI) protein adducts trigger mitochondrial oxidative/nitrosative stress during hepatocyte necrosis, danger-associated molecular patterns (DAMPs) are released to elicit sterile inflammation, and certain growth factors contribute to liver regeneration. Finally, we describe the current potential treatment options for AILI patients and promising novel strategies available to researchers and pharmacists. This review provides a clearer understanding of AILI-related mechanisms to guide drug screening and selection for the clinical treatment of AILI patients in the future.

Jiegeng Decoction Potentiates the Anticancer Efficacy of Paclitaxel in vivo and in vitro

Paclitaxel (PTX) has been the first-line treatment for lung cancer; however, its clinical use is limited due to multidrug resistance (MDR) and adverse effects. Thus, there is an urgent need to explore agents that can enhance the anticancer efficacy of PTX by reducing drug resistance and adverse reactions. Jiegeng decoction (JG) was used as the meridian guide drug and adjuvant drug in treatment of lung cancer. However, the mechanism of adjuvant effect was unclear. The aim of this study was to determine whether JG could potentiate the anticancer effect of PTX. Tissue distribution of PTX was detected using HPLC-MS/MS. The anti-lung cancer effect of the combination of PTX and JG in Lewis lung cancer C57BL/6J mice was evaluated based on the body weight and tumor-inhibition rate. PTX concentration in tumors was determined using HPLC-MS and in vivo imaging. Biochemical indices were detected using biochemical analyzer and ELISA. The anticancer mechanism of the PTX-JG combination in A549/PTX cells was elucidated based on cell proliferation, annexin V-FITC apoptosis assay, and western blotting. Tissue distribution analysis showed that the distribution of PTX increased in the lungs, liver, and heart upon administering the combination of PTX and JG. JG remarkably enhanced the anticancer effect of PTX by increasing the red blood cell and platelet counts; increasing hemoglobin, interleukin (IL)-2, and tumor necrosis factor-α levels; increasing CD4+T cells and the CD4+/CD8+ ratio; and decreasing IL-10 levels. JG administration led to the increased distribution of PTX at the tumor lesion sites and also potentiated the anticancer effect of PTX by inhibiting tumor cell proliferation and promoting apoptosis. Moreover, JG reversed PTX resistance by inhibiting the expression of lung resistance-related proteins, multiresistance protein 1, P-glycoprotein, and breast cancer-resistant protein. Furthermore, the combination of JG and PTX decreased alanine aminotransferase and aspartate aminotransferase levels and did not affect creatine kinase-MB levels. Therefore, our discovery suggests that JG increased the anticancer effect of PTX by downregulating the MDR-related protein and demonstrated a synergistic enhancement of immunity. Thus, the combination of PTX with JG shows potential in the management of lung cancer owing to its synergistic and detoxifying effects.

The dual role of immune response in acetaminophen hepatotoxicity: Implication for immune pharmacological targets

Acetaminophen (APAP), one of the most widely used antipyretic and analgesic drugs, principally contributes to drug-induced liver injury when taken at a high dose. APAP-induced liver injury (AILI) results in extensive necrosis of hepatocytes along with the occurrence of multiple intracellular events such as metabolic activation, cell injury, and signaling pathway activation. However, the specific role of the immune response in AILI remains controversial for its complicated regulatory mechanisms. A variety of inflammasomes, immune cells, inflammatory mediators, and signaling transduction pathways are activated in AILI. These immune components play antagonistic roles in aggravating the liver injury or promoting regeneration. Recent experimental studies indicated that natural products showed remarkable therapeutic effects against APAP hepatotoxicity due to their favorable efficacy. Therefore, this study aimed to review the present understanding of the immune response in AILI and attempted to establish ties among a series of inflammatory cascade reactions. Also, the immune molecular mechanisms of natural products in the treatment of AILI were extensively reviewed, thus providing a fundamental basis for exploring the potential pharmacological targets associated with immune interventions.

Transcriptome analysis identifies putative genes involved in triterpenoid biosynthesis in Platycodon grandiflorus

Comprehensive transcriptome analysis of different Platycodon grandiflorus tissues discovered genes related to triterpenoid saponin biosynthesis. Platycodon grandiflorus (Jacq.) A. DC. (P. grandiflorus), a traditional Chinese medicine, contains considerable triterpenoid saponins with broad pharmacological activities. Triterpenoid saponins are the major components of P. grandiflorus. Here, single-molecule real-time and next-generation sequencing technologies were combined to comprehensively analyse the transcriptome and identify genes involved in triterpenoid saponin biosynthesis in P. grandiflorus. We quantified four saponins in P. grandiflorus and found that their total content was highest in the roots and lowest in the stems and leaves. A total of 173,354 non-redundant transcripts were generated from the PacBio platform, and three full-length transcripts of β-amyrin synthase, the key synthase of β-amyrin, were identified. A total of 132,610 clean reads obtained from the DNBSEQ platform were utilised to explore key genes related to the triterpenoid saponin biosynthetic pathway in P. grandiflorus, and 96 differentially expressed genes were selected as candidates. The expression levels of these genes were verified by quantitative real-time PCR. Our reliable transcriptome data provide valuable information on the related biosynthesis pathway and may provide insights into the molecular mechanisms of triterpenoid saponin biosynthesis in P. grandiflorus.

Platycodin D enhances LDLR expression and LDL uptake via down-regulation of IDOL mRNA in hepatic cells

The root of Platycodon grandiflorum (PG) has long been used as a traditional herbal medicine in Asian country. Platycondin D (PD), triterpenoid saponin that is a main constituent of PG, exhibits various biological activities such as anti-inflammatory, anti-oxidant, anti-diabetic, and anti-cancer effects. A previous study showed that PD had cholesterol-lowering effects in mice that develop hypercholesterolemia, but the underlying molecular mechanisms have not been elucidated during the last decade. Here, we demonstrated that both PG and PD markedly increased levels of cell surface low-density lipoprotein receptor (LDLR) by down-regulation of the E3 ubiquitin ligase named inducible degrader of the LDLR (IDOL) mRNA, leading to the enhanced uptake of LDL-derived cholesterol (LDL-C) in hepatic cells. Furthermore, cycloheximide chase analysis and in vivo ubiquitination assay revealed that PD increased the half-life of LDLR protein by reducing IDOL-mediated LDLR ubiquitination. Finally, we demonstrated that treatment of HepG2 cells with simvastatin in combination with PG and PD had synergistic effects on the improvement of LDLR expression and LDL-C uptake. Together, these results provide the first molecular evidence for anti-hypercholesterolemic activity of PD and suggest that PD alone or together with statin could be a potential therapeutic option in the treatment of atherosclerotic cardiovascular disease.

Coenzyme Q10 nullified khat-induced hepatotoxicity, nephrotoxicity and inflammation in a mouse model

Ethnopharmacological relevance

The consumption of khat (Catha Edulis, Forsk) is on the rise despite the much publicized associated deleterious health effects. How chemicals present in khat, affect various physiological and biochemical processes requires further scrutiny. A clear understanding of these processes will provide an avenue for countering khat-driven negative effects using appropriate pharmacological and/or nutritional interventions.

Aim of the study

The current study investigated the effect of khat on vital physiological and biochemical processes such as oxidative stress, inflammation and immune responses and the role of Coenzyme-Q₁₀ (CoQ₁₀), a potent antioxidant and anti-inflammatory, in modulating any negative effects due to khat exposure.

Methodology

Three (3) weeks old forty (40) Swiss albino mice were randomly assigned into four treatment groups (n = 10). The first group was the control that was not administered with khat or CoQ₁₀. The second group received 200 mg/kg body weight (b/w) of CoQ₁₀, while the third group received 1500 mg/kg b/w of khat extract and finally the forth group was co-treated with 200 mg/kg b/w of CoQ₁₀ and 1500 mg/kg b/w of khat extract. The experiment was conducted for 90 days after which samples were collected for physiological and biochemical analyses.

Results

The effects of khat and CoQ₁₀ on the weights of brain, liver, kidney and spleen was determined. Administration of khat decreased the levels of RBCs and its subtypes (MCV, MCH, RDW-SD and RDW-CV), a clear indicator of khat-induced normochromic microcytic anemia. White blood cells (lymphocytes, monocytes, neutrophils and eosinophil) which are vital in responding to infections were markedly elevated by khat. Moreover, these results provide evidence for khat-induced liver and kidney injury as shown by increased biomarkers; AST, ALT, GGT and creatinine respectively. Standard histopathological analysis confirmed this finding for khat-driven liver and kidney injury. Further studies showed evidence for khat-induced inflammation and oxidative stress as depicted by increased levels of the pro-inflammatory cytokine TNF-alpha and elevation of GSH in the brain, liver and spleen. Remarkably, this is the first study to demonstrate the potential of CoQ₁₀ in ameliorating khat-induced negative effects as outlined. CoQ₁₀ supplementation restored the khat-induced reduction in RBC subtypes, and was protective against liver and kidney injury as shown by the appropriate biomarkers and standard histopathology analysis. The other significant finding was the CoQ₁₀-driven normalization of GSH and TNF-α levels, indicating a protective effect from khat-driven oxidative stress and inflammation respectively.

Conclusion

From this study, we conclude that CoQ₁₀ may be useful in nullifying khat-driven deleterious events among chronic khat users.

Platycodin D suppresses cisplatin-induced cytotoxicity by suppressing ROS-mediated oxidative damage, apoptosis, and inflammation in HEK-293 cells

Cisplatin, a proven effective chemotherapeutic agent, has been used clinically to treat malignant solid tumors, whereas its clinical use is limited by serious side effect including nephrotoxicity. Platycodin D (PD), the major and marked saponin isolated from Platycodon grandiflorum, possesses many pharmacological effects. In this study, we evaluated its protective effect against cisplatin-induced human embryonic kidney 293 (HEK-293) cells injury and elucidated the related mechanisms. Our results showed that PD (0.25, 0.5, and 1 μM) can dose-dependently alleviate oxidative stress by decreasing malondialdehyde and reactive oxygen species, while increasing the levels of glutathione, superoxide dismutase, and catalase. Moreover, the elevation of apoptosis including Bax, Bad, cleaved caspase-3,-9, and decreased protein levels of Bcl-2, Bcl-XL induced by cisplatin were reversed after PD treatment. Importantly, PD pretreatment can also regulate PI3K/Akt and ERK/JNK/p38 signaling pathways. Furthermore, PD was found to reduce NF-κB-mediated inflammatory relative proteins. Our finding indicated that PD exerted significant effects on cisplatin induced oxidative stress, apoptosis and inflammatory, which will provide evidence for the development of PD to attenuate cisplatin-induced nephrotoxicity.

Bioactive platycodins from Platycodonis Radix: Phytochemistry, pharmacological activities, toxicology and pharmacokinetics

Platycodonis Radix, the root of Platycodon grandiflorum (Jacq.) A. DC., is a well-known edible herbal medicine. It is a common vegetable used for the preparation of side dish, kimchi, dessert, and tea. Besides, it has been used to treat respiratory disease including cough, excessive phlegm, and sore throat for a long history. In the past decades, the bioactive components and the pharmacological activities of Platycodonis Radix have been widely investigated. Thereinto, platycodins, the oleanane-type triterpenoid saponins were demonstrated to be the main bioactive components in Platycodonis Radix, and more than 70 platycodins have been identified up to date. This paper mainly reviewed the phytochemistry, pharmacological activities (apophlegmatic, anti-tussive, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, immunomodulatory, cardiovascular protective, and hepatoprotective activities, etc.), toxicology and pharmacokinetics of platycodins isolated from Platycodonis Radix, aiming to promote further investigation on therapeutic potential of these platycodins.

The PI3K/Akt and NF-κB signaling pathways are involved in the protective effects of Lithocarpus polystachyus (sweet tea) on APAP-induced oxidative stress injury in mice

Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity. The leaves of Lithocarpus polystachyus Rehd. (named as “sweet tea”, ST) usually serve as tea drink and folk medicine for healthcare in the southwest part of China. In previous reports, it has been proven to protect various animal models, except for APAP-induced liver injury model. Therefore, this study initially explored the protective effect of ST leaf extract (STL-E) on hepatotoxicity induced by APAP in ICR mice. STL-E of 50 and 100 mg kg⁻¹ were given to each group for 7 days. ALI was intraperitoneally induced by APAP treatment (i.p. 250 mg per kg body weight). Biochemical markers, levels of inflammatory factors, histopathological staining and western blotting were used to analyze the inflammation and apoptosis of liver tissues. Interestingly, the treatment with STL-E significantly attenuated APAP-induced liver injury (p < 0.05). Moreover, STL-E partially mitigated APAP-induced liver injury by effectively activating the PI3K/Akt pathway and inhibiting the NF-κB pathway. In a word, STL-E protected liver against APAP-induced hepatotoxicity by inhibiting the PI3K/Akt-mediated apoptosis signal pathway and inhibiting the NF-κB-mediated signaling pathway.

Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity.

Omega-3 fatty acids protect against acetaminophen-induced hepatic and renal toxicity in rats through HO-1-Nrf2-BACH1 pathway

Although acetaminophen (APAP) is a commonly used analgesic antipyretic drug, hepatotoxicity and nephrotoxicity are common after the overdose. The main mechanism of APAP toxicity is oxidative stress based. Stress may induce the production of heme oxygenase 1 (HO)-1 which is regulated by interleukin (IL)-10 and inhibit the production of tumor necrosis factor-alpha (TNF-α). HO-1 expression is further regulated by nuclear factor erythroid 2-related factor 2 (Nrf2) and the transcription factor BTB and CNC homology 1 (BACH1). Drug-induced toxicity can be relieved by several natural products, which are preferred due to their dietary nature and less adverse reactions. Of these natural products, omega-3 (ω-3) fatty acids are known for anti-inflammatory and antioxidant actions. However, effects of ω-3fatty acids on APAP-induced hepatic and renal toxicity are not well addressed. We designed this study to test the potential protecting actions of ω-3 fatty acids (270 mg/kg Eicosapentaenoic acid and 180 mg/kg docosahexaenoic acid, orally, for 7 days) in hepatotoxicity and nephrotoxicity induced by APAP (2 g/kg, once orally on day 7) in rats. Moreover, we focused on the molecular mechanism underlying APAP hepatotoxicity and nephrotoxicity. Pre-treatment with ω-3 fatty acids enhanced liver and kidney functions indicated by decreased serum aminotransferases activities and serum creatinine and urea concentrations. These results were further confirmed by histopathological examination. Moreover, ω-3 fatty acids showed antioxidant properties confirmed by decreased malondialdehyde level and increased total antioxidant capacity. Antioxidant Nrf2, its regulators (HO-1 and BACH1) and the anti-inflammatory cytokine (IL-10) were up-regulated by APAP administration as a compensatory mechanism and they were normalized by ω-3 fatty acids. ω-3 fatty acids showed anti-inflammatory actions through down-regulating nuclear factor kappa B (NF-ĸB) and its downstream TNF-α. Moreover, Western blot analysis showed that ω-3 fatty acids promoted Nrf2 translocation to the nucleus; BACH1 exit from the nucleus and inhibited NF-ĸB nuclear translocation. These findings suggested the protecting actions of ω-3 fatty acids against APAP-induced hepatic and renal toxicity through regulation of antioxidant Nrf2 and inflammatory NF-ĸB pathways.

Intervention Study on the Efficacy and Safety of Platycodon grandiflorus Ethanol Extract in Overweight or Moderately Obese Adults: A Single-Center, Randomized, Double-Blind, Placebo-Controlled Trial

Platycodon grandiflorus root extract (PGE) has shown various properties, such as anti-hyperlipidemia, anti-diabetic, and anti-obesity, but mostly in animal studies. Therefore, we conducted a preliminary study on the anti-obesity effect of PGE in 108 Korean adults (aged 20–60 years, 30 kg/m² ≥ body mass index ≥ 23 kg/m²). The participants were randomly assigned to four groups and were administered the placebo, PGE571 (571 mg as PGE), PGE1142 (1142 mg as PGE), and PGE2855 (2855 mg as PGE), independently, for 12 weeks. Body composition, nutrient intake, computed tomography scan, and plasma adipokines, as well as hepatic/renal function markers, were assessed. The PGE571 group revealed a significant decrease in body fat mass and body fat percentage when compared with the placebo group. Moreover, the total abdominal and subcutaneous fat areas were significantly decreased following PGE (PGE2855 group) supplementation. These results provide useful information on the anti-obesity effect of PGE for overweight and obese adult humans.

Microvesicles Derived from TGF-β1 Stimulated Hepatic Stellate Cells Aggravate Hepatocellular Injury

Hepatic stellate cells (HSCs) are liver-specific cells playing critical roles in liver physiological and pathophysiological processes. Transforming growth factor-β1 (TGF-β1) is an inflammatory cytokine secreted by both hepatocytes and HSCs. We have previously shown that microvesicles (MVs) derived from quiescent HSCs protect hepatocyte functions. In this study, we investigated the effects of MVs released from TGF-β1-stimulated HSCs (HSC-MVs) on xenobiotic-injured hepatocytes. Two hepatocyte cell lines (BRL-3A and HL-7702) were treated with N-acetyl-p-aminophenol or H₂O₂ to build the injury models. Different concentrations of HSC-MVs were used to coculture with injured hepatocytes. MTT, Hochest33258 staining, and flow cytometry were used to determine their effects on the viability and apoptosis of hepatocytes. Liver injury indicators, alanine aminotransferase (ALT) and aspartate amino transferase (AST), were assessed by enzyme-linked immune sorbent assay kits. The phosphoinositide 3-kinase (PI3K) activator (740Y-P) and extracelluar signal regulated kinase (Erk)1/2 activator (platelet-derived growth factor-BB) were used for pathway analysis. The expression levels of p-PI3K/PI3K, p-Akt/Akt, and activated caspase-3 were measured by western blot. Results showed that (i) HSC-MVs dose dependently impaired the viability of hepatocytes in both injury models, (ii) moreover, HSC-MVs dose dependently increased the apoptosis in those cell models, (iii) HSC-MVs also elevated the levels of ALT and AST in the coculture media, and (iv) these effects were accompanied by a decrease in p-PI3K/PI3K and p-Akt/Akt, which could be partially abolished by 740Y-P. Meanwhile, the proapoptotic effect of HSC-MVs was associated with p-Erk1/2/Erk1/2 downregulation and activated caspase-3 upregulation, and could be inhibited by Erk1/2 activation. Our findings demonstrate that HSC-MVs are involved in inflammatory hepatocytes injury probably through the PI3K/Akt, Erk1/2, and caspase-3 pathways.

Hepatoprotective Effect of Baicalein Against Acetaminophen-Induced Acute Liver Injury in Mice

Baicalein (BAI), one of the main components of Scutellaria baicalensis Georgi, possesses numerous pharmacological properties, including anti-cancer, anti-oxidative, anti-virus and anti-bacterial activities. The purpose of this study was to evaluate the hepatoprotective effect of baicalein against acetaminophen (APAP)-exposed liver injury in mice, and elucidate the underlying hepatoprotective mechanism. Baicalein pretreatment significantly alleviated the elevation of IL-6, IL-1β and TNF-α in serum and hepatic in a dose-dependent manner. It also dose-dependently reduced the hepatic malondialdehyde (MDA) concentration, as well as the depletion of hepatic superoxide dismutase (SOD), hepatic glutathione (GSH) and hepatic catalase (CAT). Moreover, pretreatment with baicalein significantly ameliorated APAP-exposed liver damage and histological hepatocyte changes. Baicalein also relieved APAP-induced autophagy by regulating AKT/mTOR pathway, LC3B and P62 expression. Furthermore, the hepatoprotective effect of baicalein to APAP-induced liver injury involved in Jak2/Stat3 and MAPK signaling pathway. Taken together, our findings suggested that baicalein exhibits the ability to prevent liver from APAP-induced liver injury and provided an underlying molecular basis for potential applications of baicalein to cure liver injuries.