Novel mouse model of combined hyperlipidemia associated with steatosis and liver injury by a single-dose intragastric administration of schisandrin B/cholesterol/bile salts mixture

Effectors of Hyperlipidemia among HIV/AIDS patients with second-line antiretroviral therapy based on register data

OBJECTIVE

In this study, we aimed to determine the prevalence and effectors of hyperlipidemia among people living with HIV/AIDS (PLWHA) and taking second-line antiretroviral therapy (ART) using registry data in central China.

METHODS

We conducted a cross-sectional study and collected information of PLWHA on second-line ART during 2018 from two medical registries. Hyperlipidemia was defined according to the 2016 Chinese guidelines for the management of dyslipidemia in adults. Univariate and multivariate logistic regression analyses were performed to explore the influencing factors of hyperlipidemia. We calculated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 2886 PLWHA taking second-line ART were included in this study, and 978 (33.9%) had hyperlipidemia. Female patients, those with hyperglycemia, and patients with CD4+ cell counts >500 cells/μL had a higher prevalence of hyperlipidemia with 37.0%, 49.0%, and 41.3%, respectively. Multivariate analysis showed that CD4+ cell count 350-500 cells/μL (OR=1.72, 95% CI: 1.26-2.38), CD4+ cell count >500 cells/μL (OR=2.49, 95% CI: 1.85-3.38), and FPG >6.2 mmol/L (OR=2.08, 95% CI:1.64-2.65) were risk factors for hyperlipidemia. Male sex (OR=0.72, 95% CI: 0.61-0.85) and Hb <110 g/L (OR=0.59, 95% CI: 0.45-0.76) were protective factors against hyperlipidemia.

CONCLUSIONS

PLWHA on second-line ART had a higher prevalence of hyperlipidemia. Gender, CD4+ cell count, FPG, and hemoglobin were influencing factors of hyperlipidemia.

Impact of fenofibrate on NAFLD/NASH: A genetic perspective

Nonalcoholic fatty liver disease (NAFLD), caused by an accumulation of fat deposits in hepatocytes, prevalently affects at least one-third of the world's population. The progression of this disorder can potentially include a spectrum of consecutive stages, specifically: steatosis, steatohepatitis and cirrhosis. Fenofibrate exhibits potential therapeutic efficacy for NAFLD owing to several properties, which include antioxidant, apoptotic, anti-inflammatory and antifibrotic activity. In the present review, we discuss the direct or indirect impact of fenofibrate on genes involved at various stages in the progression of NAFLD. Moreover, we have reviewed studies that compare fenofibrate with other drugs in treating NAFLD, as well as recent clinical trials, in an attempt to identify reliable scientific and clinical evidence concerning the therapeutic effects and benefits of fenofibrate on NAFLD. Teaser.

Investigation of the Effect of Curcumin on Protein Targets in NAFLD Using Bioinformatic Analysis

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a prevalent metabolic disorder. Defects in function/expression of genes/proteins are critical in initiation/progression of NAFLD. Natural products may modulate these genes/proteins. Curcumin improves steatosis, inflammation, and fibrosis progression. Here, bioinformatic tools, gene−drug and gene-disease databases were utilized to explore targets, interactions, and pathways through which curcumin could impact NAFLD. METHODS: Significant curcumin−protein interaction was identified (high-confidence:0.7) in the STITCH database. Identified proteins were investigated to determine association with NAFLD. gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were analyzed for significantly involved targets (p < 0.01). Specificity of obtained targets with NAFLD was estimated and investigated in Tissue/Cells−gene associations (PanglaoDB Augmented 2021, Mouse Gene Atlas) and Disease−gene association-based EnrichR algorithms (Jensen DISEASES, DisGeNET). RESULTS: Two collections were constructed: 227 protein−curcumin interactions and 95 NAFLD-associated genes. By Venn diagram, 14 significant targets were identified, and their biological pathways evaluated. Based on gene ontology, most targets involved stress and lipid metabolism. KEGG revealed chemical carcinogenesis, the AGE-RAGE signaling pathway in diabetic complications and NAFLD as the most common significant pathways. Specificity to diseases database (EnrichR algorithm) revealed specificity for steatosis/steatohepatitis. CONCLUSION: Curcumin may improve, or inhibit, progression of NAFLD through activation/inhibition of NAFLD-related genes.

Tanshinol A Ameliorates Triton-1339W-Induced Hyperlipidemia and Liver Injury in C57BL/6J Mice by Regulating mRNA Expression of Lipemic-Oxidative Injury Genes

Tanshinol A, which is derived from a traditional Chinese herbal Radix Salviae Miltiorrhizae is indicative of a hypolipidemic candidate. Therefore, we aim to validate its hypolipidemic activity of tanshinol A and explore its mechanism in triton-1339W-induced hyperlipidemic mice model, which possess multiply pathogenesis for endogenous lipid metabolism disorder. Experimental hyperlipidemia mice are treated with or without tanshinol A (i.g. 40, 20, 10 mg/kg), and blood and liver tissue were collected for validating its hypolipidemic and hepatic protective effect, and hepatic mRNA expression profile, which was associated with lipid metabolism dysfunction and liver injury, was detected by RT-qPCR. As results show, triton-1339W-induced abnormal of serum TC, TAG, HDL-C, LDL-C, SOD, MDA, GOT, and GPT is remarkably attenuated by tanshinol A. In pathological experiment, triton-1339W-induced hepatocellular ballooning degeneration, irregular central vein congestion, and inflammation infiltration are alleviated by tanshinol A. Correspondingly, hepatic mRNA expression of Atf4, Fgf21, Vldlr, Nqo1, Pdk4, and Angptl4, which are genes regulating lipemic-oxidative injury, are significantly increased by tanshinol A by 2~6 fold. Abcg5, Cd36, and Apob, which are responsible for cholesterol metabolism, are mildly upregulated. Noticeably, triton-1339W-suppressed expressions of Ptgs2/Il10, which are genes responsible for acute inflammation resolution in liver injury, are remarkably increased by tanshinol A. Conclusively, tanshinol A exerted hypolipidemic effect and hepatoprotective effect through restoring triton-1339W-suppressed mRNA expression, which may be involved in Atf4/Fgf21/Vldlr and Ptgs2/Il-10 signaling pathways.

Biochemical mechanism underlying hypertriglyceridemia and hepatic steatosis/hepatomegaly induced by acute schisandrin B treatment in mice

Background

It has been demonstrated that acute oral administration of schisandrin B (Sch B), an active dibenzocyclooctadiene isolated from Schisandrae Fructus (a commonly used traditional Chinese herb), increased serum and hepatic triglyceride (TG) levels and hepatic mass in mice. The present study aimed to investigate the biochemical mechanism underlying the Sch B-induced hypertriglyceridemia, hepatic steatosis and hepatomegaly.

Methods

Male ICR mice were given a single oral dose of Sch B (0.25–2 g/kg). Sch B-induced changes in serum levels of biomarkers, such as TG, total cholesterol (TC), apolipoprotein B48 (ApoB 48), very-low-density lipoprotein (VLDL), non-esterified fatty acid (NEFA) and hepatic growth factor (HGF), as well as hepatic lipids and mass, epididymal adipose tissue (EAT) and adipocyte size, and histological changes of the liver and EAT were examined over a period of 12–120 h after Sch B treatment.

Results

Serum and hepatic TG levels were increased by 1.0–4.3 fold and 40–158% at 12–72 h and 12–96 h, respectively, after Sch B administration. Sch B treatment elevated serum ApoB 48 level (up to 12%), a marker of exogenous TG, but not VLDL, as compared with the vehicle treatment. Treatment with Sch B caused a time-/dose-dependent reduction in EAT index (up to 39%) and adipocyte size (up to 67%) and elevation in serum NEFA level (up to 55%). Sch B treatment induced hepatic steatosis in a time-/dose-dependent manner, as indicated by increases in total vacuole area (up to 3.2 fold vs. the vehicle control) and lipid positive staining area (up to 17.5 × 10³ μm²) in liver tissue. Hepatic index and serum HGF levels were increased by 18–60% and 42–71% at 12–120 h and 24–72 h post-Sch B dosing, respectively. In addition, ultrastructural changes, such as increase in size and disruption of cristae, in hepatic mitochondria were observed in Sch B-treated mice.

Conclusion

Our findings suggest that exogenous sources of TG and the breakdown of fat storage in the body contribute to Sch B-induced hypertriglyceridemia and hepatic steatosis in mice. Hepatomegaly (a probable hepatotoxic action) caused by Sch B may result from the fat accumulation and mitochondrial damage in liver tissue.

Schisandrin B: A Double-Edged Sword in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver lesions ranging from hepatic steatosis, nonalcoholic steatohepatitis, hepatic cirrhosis, and hepatocellular carcinoma. The high global prevalence of NAFLD has underlined the important public health implications of this disease. The pathogenesis of NAFLD involves the abnormal accumulation of free fatty acids, oxidative stress, endoplasmic reticulum (ER) stress, and a proinflammatory state in the liver. Schisandrin B (Sch B), an active dibenzooctadiene lignan isolated from the fruit of Schisandra chinensis (a traditional Chinese herb), was found to possess antihyperlipidemic, antioxidant, anti-ER stress, and anti-inflammatory activities in cultured hepatocytes in vitro and in rodent livers in vivo. Whereas a long-term, low dose regimen of Sch B induces an antihyperlipidemic response in obese mice fed a high fat diet, a single bolus high dose of Sch B increases serum/hepatic lipid levels in mice. This differential action of Sch B is likely related to a dose/time-dependent biphasic response on lipid metabolism in mice. The hepatoprotection afforded by Sch B against oxidative stress, ER stress, and inflammation has been widely reported. The ensemble of results suggests that Sch B may offer potential as a therapeutic agent for NAFLD. The optimal dose and duration of Sch B treatment need to be established in order to ensure maximal efficacy and safety when used in humans.

Schisandrin B inhibits cell growth and induces cellular apoptosis and autophagy in mouse hepatocytes and macrophages: implications for its hepatotoxicity

A number of drugs and herbal compounds have been documented to cause hepatoxicity. Schisandrin B (Sch B) is an active dibenzocyclooctadiene isolated from Schisandrae fructus, with a wide array of pharmacological activities. However, the potential hepatotoxicity of Sch B is a major safety concern, and the underlying mechanism for Sch B-induced liver toxic effects is not fully elucidated. In the present study, we aimed to investigate the liver toxic effects and the molecular mechanisms of Sch B in mouse liver and macrophage cells. The results have shown that Sch B exhibits potent grow inhibitory, proapoptotic, and proautophagic effects in AML-12 and RAW 264.7 cells. Sch B markedly arrested cells in G₁ phase in both cell lines, accompanied by the down-regulation of cyclin dependent kinase 2 (CDK2) and cyclin D1 and up-regulation of p27 Kip1 and checkpoint kinase 1. Furthermore, Sch B markedly increased the apoptosis of AML-12 and RAW 264.7 cells with a decrease in the expression of B-cell lymphoma-extra-large and (Bcl-xl) B-cell lymphoma 2 (Bcl-2), but an increase in the expression of B-cell lymphoma 2-associated X protein (Bax). Sch B promoted the cleavage of caspase 3 and poly-adenosine diphosphate-ribose polymerase (PARP) in both cell lines. Additionally, Sch B significantly induced autophagy of AML-12 and RAW 264.7 cells. Sch B inhibited the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, as indicated by their altered phosphorylation, contributing to the proautophagic effect of Sch B. Taken together, our findings show that the inducing effects of Sch B on cell cycle arrest, apoptosis, and autophagy may contribute to its liver toxic effects, which might provide a clue for the investigation of the molecular toxic targets and underlying mechanisms for Sch B-induced hepatotoxicity in herbal consumers. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Sch B for clinical use.

Oral administration of Bifidobacterim bifidum for modulating microflora, acid and bile resistance, and physiological indices in mice

Bifidobacteria are generally acknowledged as major gut microflora used as probiotics, which promote human health. In this study, the effects of the administration of Bifidobacterim bifidum on modulating gastrointestinal (GI) tract microflora, acid and bile resistance, and physiological indices in BALB/c mice were investigated. Results showed that B. bifidum can significantly improve the ecosystem of the GI tract by increasing the amount of probiotics and reducing the populations of pathogenic bacteria, as measured by plate count and real-time PCR. After exposure to simulated GI tract conditions, the growth of gut microflora in the B. bifidum group was higher than that in the control group when incubated for 12 h in MRS or nutrient broth adjusted to pH 2.0 or 3.0 or in the presence of a concentration of bile salt (0.45% m/v). The blood biochemical index was examined, and the physiological effect of the cell-free extract of gut microflora was evaluated by measuring the activity of various enzymes, including α-glucosidases, esterase, and lactate dehydrogenase. This study suggested that a B. bifidum strain can stabilize blood sugar, lower cholesterol levels in serum, and improve metabolic activity. Moreover, B. bifidum was a promising enhancer of microbial diversity in mouse intestine and played a vital role in human physiological processes, which can benefit the health of a host.

Time and dose relationships between schisandrin B- and schisandrae fructus oil-induced hepatotoxicity and the associated elevations in hepatic and serum triglyceride levels in mice

Background

Schisandrin B (Sch B), a dibenzocyclooctadiene compound, is isolated from schisandrae fructus (SF). This study was conducted to compare the time- and dose-response between Sch B- and SF oil (SFO)-induced changes in hepatic and serum parameters in mice.

Methods

Institute of Cancer Research (ICR) mice were given a single oral dose of Sch B (0.125–2 g/kg) or SFO (0.3–5 g/kg). Serum alanine aminotransferase (ALT) activity, hepatic malondialdehyde, and triglyceride (TG) levels were measured at increasing time intervals within 6–120 hours postdosing.

Results

Serum ALT activity was elevated by 60%, with maximum effect (E_max) =45.77 U/L and affinity (K_D) =1.25 g/kg at 48–96 hours following Sch B, but not SFO, treatment. Sch B and SFO treatments increased hepatic malondialdehyde level by 70% (E_max =2.30 nmol/mg protein and K_D =0.41 g/kg) and 22% (E_max =1.42 nmol/mg protein and K_D =2.56 g/kg) at 72 hours postdosing, respectively. Hepatic index was increased by 16%–60% (E_max =11.01, K_D =0.68 g/kg) and 8%–32% (E_max =9.88, K_D =4.47 g/kg) at 12–120 hours and 24–120 hours after the administration of Sch B and SFO, respectively. Hepatic TG level was increased by 40%–158% and 35%–85%, respectively, at 12–96 hours and 6–48 hours after Sch B and SFO treatment, respectively. The values of E_max and K_D for Sch B/SFO-induced increase in hepatic TG were estimated to be 22.94/15.02 μmol/g and 0.78/3.03 g/kg, respectively. Both Sch B and SFO increased serum TG (up to 427% and 123%, respectively), with the values of E_max =5.50/4.60 mmol/L and K_D =0.43/2.84 g/kg, respectively.

Conclusion

The findings indicated that Sch B/SFO-induced increases in serum/hepatic parameters occurred in a time-dependent manner, with the time of onset being serum TG level < hepatic TG level < hepatic index < serum ALT activity. However, the time of recovery of these parameters to normal values varied as follow: serum TG level < hepatic TG level and liver injury < hepatic index. The E_max and affinity of Sch B on tissue/enzyme/receptor were larger than those of SFO.

Peroxisome proliferator-activated receptor α activation induces hepatic steatosis, suggesting an adverse effect

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic triglyceride accumulation, ranging from steatosis to steatohepatitis and cirrhosis. NAFLD is a risk factor for cardiovascular diseases and is associated with metabolic syndrome. Antihyperlipidemic drugs are recommended as part of the treatment for NAFLD patients. Although fibrates activate peroxisome proliferator-activated receptor α (PPARα), leading to the reduction of serum triglyceride levels, the effects of these drugs on NAFLD remain controversial. Clinical studies have reported that PPARα activation does not improve hepatic steatosis. In the present study, we focused on exploring the effect and mechanism of PPARα activation on hepatic triglyceride accumulation and hepatic steatosis. Male C57BL/6J mice, Pparα-null mice and HepG2 cells were treated with fenofibrate, one of the most commonly used fibrate drugs. Both low and high doses of fenofibrate were administered. Hepatic steatosis was detected through oil red O staining and electron microscopy. Notably, in fenofibrate-treated mice, the serum triglyceride levels were reduced and the hepatic triglyceride content was increased in a dose-dependent manner. Oil red O staining of liver sections demonstrated that fenofibrate-fed mice accumulated abundant neutral lipids. Fenofibrate also increased the intracellular triglyceride content in HepG2 cells. The expression of sterol regulatory element-binding protein 1c (SREBP-1c) and the key genes associated with lipogenesis were increased in fenofibrate-treated mouse livers and HepG2 cells in a dose-dependent manner. However, the effect was strongly impaired in Pparα-null mice treated with fenofibrate. Fenofibrate treatment induced mature SREBP-1c expression via the direct binding of PPARα to the DR1 motif of the SREBP-1c gene. Taken together, these findings indicate the molecular mechanism by which PPARα activation increases liver triglyceride accumulation and suggest an adverse effect of fibrates on the pathogenesis of hepatic steatosis.

Dietary pulp from Fructus Schisandra Chinensis supplementation reduces serum/hepatic lipid and hepatic glucose levels in mice fed a normal or high cholesterol/bile salt diet

Background

Recently, it has been found that Fructus Schisandra Chinensis (FSC), a Chinese herbal medicine, and its related compounds have a profound impact on lipid metabolism process. FSC can be divided into two parts, i.e., seed and pulp. The current study aimed to examine the effect of aqueous extracts of FSC pulp (AqFSC-P) on serum/hepatic lipid and glucose levels in mice fed with a normal diet (ND) or a high cholesterol/bile salt diet (HCBD).

Methods

The AqFSC-P used in the present study was fractionated into supernatant (SAqFSC-P) and precipitate (PAqFSC-P) separated by centrifugation. Male ICR mice were fed with ND or HCBD, without or with supplementation of 1%, 3%, or 9% (w/w) SAqFSC-P or PAqFSC-P for 10 days. Biomarkers were determined according to the manufacturer’s instruction.

Results

Supplementation with SAqFSC-P or PAqFSC-P significantly reduced serum and hepatic triglyceride levels (approximately 40%) in ND- and/or HCBD-fed mice. The supplementation with SAqFSC-P or PAqFSC-P reduced hepatic total cholesterol levels (by 27 - 46%) in HCBD-fed mice. Supplementation with SAqFSC-P or PAqFSC-P markedly lowered hepatic glucose levels (by 13 - 30%) in ND- and HCBD-fed mice. SAqFSC-P decreased serum alanine aminotransferase (ALT) activity, but PAqFSC-P increased hepatic protein contents in ND-fed mice. Bicylol, as a positive control, reduced ALT activity. In addition, mice supplemented with FSC-P or bicylol showed a smaller body weight gain and adipose tissue mass as compared to the respective un-supplemented ND- or HCBD-fed mice.

Conclusion

The results indicate that SAqFSC-P and PAqFSC-P produce hepatic lipid- and glucose-lowering as well as serum TG-lowering effects in hypercholesterolemic mice. FSC pulp may provide a safe alternative for the management of fatty liver and/or lipid disorders in humans.