Attenuated Lipid Accumulation Research Articles

Comparative hepatoprotective effects of flavonoids-rich fractions from flowers and leaves of Penthorum chinense Pursh in vitro

Ethnopharmacological relevancePenthorum chinense Pursh is a traditional Miao ethnomedicine rich in bioactive components, widely recognized for its hepatoprotective properties. However, the hepatoprotective effects of its flowers and leaves have not been individually elucidated. Aims of the studyThe objective of this study was to isolate and purify flavonoids-rich fractions from the flowers (PFF) and leaves (PLF) of P. chinense, and to assess their potential protective effects against oxidative, alcohol-induced, and free fatty acid (FFA) induced injury in hepatic cells. Materials and methodsThe P. chinense flowers and leaves flavonoids-rich fractions were extracted by the method optimized by response surface methodology, and the extracts were subsequently purified using petroleum ether and microporous column. The physical characteristics and component composition of PFF and PLF were analyzed by FT-IR and UPLC-MS/MS. The hepatoprotective activities of PFF and PLF were evaluated by the alcohol, H2O2, and FFA-induced hepatocyte injury cellular model in vitro. The protective effects of PFF and PLF on the hepatic cells were evaluated by assessing cell apoptosis rate, enzymes activities, mitochondrial membrane potential, and mRNA expression in relevant signaling pathways. ResultsThe results revealed that PFF was mainly composed of pinocembrin, quercitrin and quercetin, while PLF was predominantly composed of quercetin, pinocembrin, and kaempferol and their derivatives. PFF and PLF exhibited distinct effects on increasing the cell proliferation rate, regulating the MDA, GOT and GPT levels, and modulating the mRNA expression in apoptosis and antioxidant pathways in alcohol damaged LO2 cells. PFF exhibited superior efficacy in reducing cell apoptosis in alcohol-damage cells compared to PLF. Both PFF and PLF alleviated mitochondrial stress in H2O2-induced LO2 cells. Additionally, the PFF and PLF attenuated lipid accumulation and activated mRNA expressions in PPARα/ACOX1/CPT-1 lipid metabolism pathways, as well as Nrf2/ARE oxidative stress pathways. ConclusionThis study compared the hepatoprotective activities of flavonoids-rich fractions purified from the flowers and leaves of P. chinense. The results contribute to the enhanced development and utilization of various parts of P. chinense aimed at medical and health food applications.

Platycodin D ameliorates polycystic ovary syndrome-induced ovarian damage by upregulating CD44 to attenuate ferroptosis

Recently, the potential association between polycystic ovary syndrome (PCOS) development and progression and ferroptosis has garnered attention. Increasing evidence suggests that targeting ferroptosis may be an effective strategy for treating PCOS. First, we observed that the expression of the ferroptosis regulatory molecules SLC7A11, GPX4, and FTH1 was decreased in the granulosa cells (GCs) of patients with PCOS and ovarian tissues of rats with PCOS; in contrast, TFR1 expression was increased. This suggests that GC ferroptosis is involved in PCOS pathogenesis. Furthermore, bioinformatics analysis of GC datasets from patients with PCOS and PCOS clinical samples and animal model analysis revealed CD44 as a key molecule regulating ferroptosis in PCOS, which was down-regulated in GCs of PCOS patients and rats. Subsequently, molecular docking was performed to screen existing natural compounds for inhibiting ferroptosis. Dynamic simulation and cellular thermal shift assay identified platycodin D as a natural plant extract for inhibiting ferroptosis by targeting CD44 in GCs. Subsequently, a series of functional experiments revealed that platycodin D ameliorated ovarian damage in rats with PCOS. This was primarily owing to the protective effects achieved by promoting glutathione production, attenuating lipid accumulation and lipid peroxidation in GCs, inhibiting iron overload, and scavenging reactive oxygen species. In addition, western blotting and immunofluorescence staining revealed that platycodin D upregulated the expression of CD44 and SLC7A11 in GCs. Furthermore, by knocking down CD44 and SLC7A11 in vivo and in vitro, respectively, the ameliorative effect of platycodin D on ferroptosis in the GCs of rats with PCOS was reversed. Collectively, these findings suggest that platycodin D attenuates ferroptosis in GCs by activating CD44/SLC7A11 axis, thereby upregulating system Xc−. In conclusion, platycodin D can attenuate ferroptosis in GCs by activating CD44, potentially ameliorating ovarian damage in PCOS.

Bushen Huoxue formula attenuates lipid accumulation evoking excessive autophagy in premature ovarian insufficiency rats and palmitic acid-challenged KGN cells by modulating lipid metabolism.

Premature ovarian insufficiency (POI) has affected about 3.7% of women of reproductive age and is a major factor contributing to infertility. Bushen Huoxue formula (BHF), a traditional Chinese medicine prescription, is clinically used to treat POI in China. This study aims to investigate the potential mechanisms of BHF in combating POI using corticosterone-induced rats and palmitic acid (PA)-challenged human ovarian granulosa cells (GCs). Initially, ultra performance liquid chromatography tandem mass spectrometry was employed to analyze the components of BHF. The pharmacodynamic parameters evaluated included body weight, ovaries index, and serum hormone in rats. Follicle numbers were observed using H&E staining. Additionally, PCNA and TUNEL staining were used to assess GCs proliferation and apoptosis, respectively. Lipid accumulation and ROS levels were examined using Oil Red O and ROS staining. Protein expressions were determined by western blot. To probe mechanisms, cell viability and E2 levels in BHF-treated, PA-stimulated GCs were determined using MTT and ELISA, respectively. Cell apoptosis and ROS levels were assessed using TUNEL and ROS staining. Proteins related to lipid metabolism and autophagy in PA-stimulated GCs were studied using agonists. Our results shown that BHF effectively normalized serum hormone levels, including follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), estradiol (E2), and luteinizing hormone (LH). Concurrently, BHF also significantly reduced follicular atresia and promoted cell proliferation while inhibiting apoptosis in POI rats. Furthermore, BHF mitigated ovarian lipid accumulation by modulating lipid metabolism, which included reducing lipid synthesis (expression of peroxisome proliferator-activated receptor γ and CCAAT/enhancer binding protein α), increasing lipid catabolism (expression of adipose triglyceride lipase), and enhancing lipid oxidation (expression of carnitine palmitoyl transferase 1A). Mechanistically, the therapeutic effects of BHF on POI were linked with alleviation of lipid deposition-induced reactive oxygen species (ROS) accumulation and excessive autophagy, corroborating the results in PA-challenged GCs. After treatment with elesclomol (a ROS inducer) and rapamycin (an autophagy inducer) in GCs, the effects of BHF were almost counteracted under model conditions. These findings suggest that BHF alleviates the symptoms of POI by altering lipid metabolism and reducing lipid accumulation-induced ROS and autophagy, offering evidence for BHF's efficacy in treating POI clinically.

Discovery of N-Aryl-N'-[4-(aryloxy)cyclohexyl]squaramide-Based Inhibitors of LXR/SREBP-1c Signaling Pathway Ameliorating Steatotic Liver Disease: Navigating the Role of SIRT6 Activation.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is primarily attributed to the abnormal upregulation of hepatic lipogenesis, which is especially caused by the overactivation of the liver X receptor/sterol regulatory element-binding protein-1c (LXR/SREBP-1c) pathway in hepatocytes. In this study, we report the rational design and synthesis of a novel series of squaramides via bioisosteric replacement, which was evaluated for its inhibitory activity on the LXR/SREBP-1c pathway using dual cell-based assays. Compound 31 was found to significantly downregulate LXR, SREBP-1c, and their target genes associated with lipogenesis. Further investigation revealed that compound 31 may indirectly inhibit the LXR/SREBP-1c pathway by activating the upstream regulator sirtuin 6 (SIRT6). Encouragingly, compound 31 substantially attenuated lipid accumulation in HepG2 cells and in the liver of high-fat-diet-fed mice. These findings suggest that compound 31 holds promise as a candidate for the development of treatments for MASLD and other lipid metabolism-related diseases.

Excretory/secretory antigens from Trichinella spiralis muscle larvae ameliorate HFD-induced non-alcoholic steatohepatitis via driving macrophage anti-inflammatory activity

No approved effective therapy for non-alcoholic steatohepatitis (NASH) is currently available. Trichinella spiralis (T. spiralis) infection and their products have positive impact on several metabolic diseases. Considering, we firstly investigated the effects of the T. spiralis-derived Excretory-Secretory antigens (ESA) on high fat diet (HFD)-induced NASH mouse models. To further elucidate the mechanism of action, HepG2 cells were incubated with palmitic acid (PA) to construct NASH-like cell model, and then the culture medium supernatant collected from ESA-treated macrophages was applied to intervene the cell model in vitro. In NASH mouse models, ESA significantly alleviated hepatic steatosis and hepatic inflammation, as reflected by reducing pro-inflammatory cytokines and inactivating TLR4/MYD88/NF-κB pathway and NLRP3 inflammasome. Meanwhile, the HFD-induced oxidative stress was restored by ESA through lessening the level of MDA, increasing the activity of T-SOD and enhancing Nrf2 signaling-related proteins, including p-Nrf2, NQO1, HO-1, GPX4, and p-AMPK. Notably, ESA preferentially promoted macrophages polarization toward M2 anti-inflammatory phenotype in vivo and vitro. Moreover, in vitro, intervention of PA-treated HepG2 cells with medium supernatant of ESA-treated macrophages attenuated lipid accumulation, inflammation, as well as oxidative stress. In conclusion, T. spiralis-derived ESA may serve as a novel promising candidate for the treatment of NASH via its properties of driving macrophage anti-inflammatory activity.

Enhanced lipid metabolism reprogramming in CHF rats through IL-6-mediated cardiac glial cell modulation by digilanid C and electroacupuncture stimulation combination.

Cardiac lipid metabolism reprogramming is recognized as a critical pathological factor in the progression of chronic heart failure (CHF). The therapeutic potential of digilanid C and electroacupuncture stimulation (ES) in enhancing lipid metabolism and cardiac function has been established. However, the optimal synergistic regulatory strategies of these interventions on cardiac lipid metabolism have yet to be elucidated. This study aimed to comprehensively evaluate the impact of a digilanid C-ES combination on cardiac steatosis remodeling in CHF. Assessments were conducted across various dimensions, including myocardial oxygen consumption, mitochondrial function, and lipid metabolism. Additionally, we sought to uncover the underlying neuromolecular mechanisms. Our findings, at both molecular and morphological levels, indicated that the synergistic application of digilanid C and ES significantly inhibited myocardial fibrosis and steatosis. This combination therapy facilitated the repair of cardiac neuro-vascular uncoupling and induced a reprogramming of lipid metabolism. Notably, the digilanid C-ES combination ameliorated cardiomyocyte apoptosis and enhanced mitochondrial biogenesis in CHF, leading to a restructured energy supply pattern. Cardiac immunofluorescence analyses revealed the aggregation of cardiac glial cells (CGCs) at sites of abnormal neurovascular coupling, a response to cardiac lipid degeneration. This was accompanied by a marked reduction in the abnormally elevated expression of interleukin 6 (IL-6) and glutamatergic signaling, which correlated with the severity of cardiac steatosis and the aberrant activation of CGCs. The combined therapy was found to activate the Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3) pathway, effectively attenuated lipid accumulation and over-recruitment of CGCs and deprivation of glutamatergic nerves. These findings underscore the potential of digilanid C and ES combination therapy as a novel approach to modulate the complex interplay between neurovascular dynamics and metabolic dysregulation in CHF.

GTPBP8 mitigates nonalcoholic steatohepatitis (NASH) by depressing hepatic oxidative stress and mitochondrial dysfunction via PGC-1α signaling

Nonalcoholic steatohepatitis (NASH) is emerging as a major cause of liver transplantation and hepatocellular carcinoma (HCC). Regrettably, its pathological mechanisms are still not fully comprehended. GTP-binding protein 8 (GTPBP8), belonging to the GTP-binding protein superfamily, assumes a crucial role in RNA metabolism, cell proliferation, differentiation, and signal transduction. Its aberrant expression is associated with oxidative stress and mitochondrial dysfunctions. Nevertheless, its specific functions and mechanisms of action, particularly in NASH, remain elusive. In our current study, we initially discovered that human hepatocytes L02 displayed evident mitochondrial respiratory anomaly, mitochondrial damage, and dysfunction upon treatment with palmitic acids and oleic acids (PO), accompanied by significantly reduced GTPBP8 expression levels through RNA-Seq, RT-qPCR, western blotting, and immunofluorescence assays. We then demonstrated that GTPBP8 overexpression mediated by adenovirus vector (Ad-GTPBP8) markedly attenuate lipid accumulation, inflammatory response, and mitochondrial impair and dysfunction in hepatocytes stimulated by PO. Conversely, adenovirus vector-mediated GTPBP8 knockdown (Ad-shGTPBP8) significantly accelerated lipid deposition, inflammation and mitochondrial damage in PO-treated hepatocytes in vitro. Furthermore, we constructed an in vivo NASH murine model by giving a 16-week high fat high cholesterol diet (HFHC) diet to hepatocyte specific GTPBP8-knockout (GTPBP8HKO) mice. We firstly found that HFHC feeding led to metabolic disorder in mice, including high body weight, blood glucose and insulin levels, and liver dysfunctions, which were accelerated in these NASH mice with GTPBP8 deficiency in hepatocytes. Consistently, GTPBP8HKO remarkably exacerbated the progression of NASH phenotypes induced by HFHC, as proved by the anabatic lipid accumulation, inflammation, fibrosis and reactive oxygen species (ROS) production in liver tissues, which could be largely attributed to the severe mitochondrial damage and dysfunction. Mechanistically, we further identified that GTPBP8 interacted with peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in hepatocytes. Importantly, the hepaprotective effects of GTPBP8 against mitochondrial dysfunction, oxidative stress and inflammation was largely dependent on PGC-1α expression. Collectively, GTPBP8 may exert a protective role in the progression of NASH, and targeting the GTPBP8/PGC-1α axis may represent a potential strategy for NASH treatment by improving mitochondrial functions.

Salusin‑α alleviates lipid metabolism disorders via regulation of the downstream lipogenesis genes through the LKB1/AMPK pathway.

Lipid metabolism disorders are a major cause of several chronic metabolic diseases which seriously affect public health. Salusin‑α, a vasoactive peptide, has been shown to attenuate lipid metabolism disorders, although its mechanism of action has not been reported. To investigate the effects and potential mechanisms of Salusin‑α on lipid metabolism, Salusin‑α was overexpressed or knocked down using lentiviral vectors. Hepatocyte steatosis was induced by free fatty acid (FFA) after lentiviral transfection into HepG2 cells. The degree of lipid accumulation was assessed using Oil Red O staining and by measuring several biochemical indices. Subsequently, bioinformatics was used to analyze the signaling pathways that may have been involved in lipid metabolism disorders. Finally, semi‑quantitative PCR and western blotting were used to verify the involvement of the liver kinase B1 (LKB1)/AMPK pathway. Compound C, an inhibitor of AMPK, was used to confirm this mechanism's involvement further. The results showed that Salusin‑α significantly attenuated lipid accumulation, inflammation and oxidative stress. In addition, Salusin‑α increased the levels of LKB1 and AMPK, which inhibited the expression of sterol regulatory element binding protein‑1c, fatty acid synthase and acetyl‑CoA carboxylase. The addition of Compound C abrogated the Salusin‑α‑mediated regulation of AMPK on downstream signaling molecules. In summary, overexpression of Salusin‑α activated the LKB1/AMPK pathway, which in turn inhibited lipid accumulation in HepG2 cells. This provides insights into the potential mechanism underlying the mechanism by which Salusin‑α ameliorates lipid metabolism disorders while identifying a potential therapeutic target.

TSA attenuates the progression of c-Myc-driven hepatocarcinogenesis by pAKT-ADH4 pathway

Hepatocellular carcinoma (HCC) is the primary malignant tumor of the liver. c-Myc is one of the most common oncogenes in clinical settings, and amplified levels of c-Myc are frequently found in HCC. Histone deacetylase inhibitors (HDACi), such as Trichostatin A (TSA), hold enormous promise for the treatment of HCC. However, the potential and mechanism of TSA in the treatment of c-Myc-induced HCC are unclear. In this study, we investigated the effects of TSA treatment on a c-Myc-induced HCC model in mice. TSA treatment delayed the development of HCC, and liver function indicators such as ALT, AST, liver weight ratio, and spleen weight ratio demonstrated the effectiveness of TSA treatment. Oil red staining further demonstrated that TSA attenuated lipid accumulation in the HCC tissues of mice. Through mRNA sequencing, we identified that TSA mainly affected cell cycle and fatty acid degradation genes, with alcohol dehydrogenase 4 (ADH4) potentially being the core molecular downstream target. QPCR, immunohistochemistry, and western blot analysis revealed that ADH4 expression was repressed by c-Myc and restored after TSA treatment both in vitro and in vivo. Furthermore, we observed that the levels of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration increased after c-Myc transfection in liver cells but decreased after TSA intervention. The levels of phosphorylated protein kinase B (p-AKT) and p-mTOR were identified as targets regulated by TSA, and they governed the ADH4 expression and the downstream regulation of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration. Overall, our study suggests that TSA has a therapeutic effect on c-Myc-induced HCC through the AKT-mTOR-ADH4 pathway. These findings provide valuable insights into the potential treatment of HCC using TSA and shed light on the underlying molecular mechanisms involved.

Chemically synthesized osteocalcin alleviates NAFLD via the AMPK-FOXO1/BCL6-CD36 pathway

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease worldwide. Osteocalcin plays an important role in energy metabolism. In this study, we investigated the mechanism of action of chemically synthesized osteocalcin (csOCN) in ameliorating NAFLD. We demonstrated for the first time that csOCN attenuates lipid accumulation in the liver and hepatocytes by modulating CD36 protein expression. In addition, we found that the expression of p-AMPK, FOXO1 and BCL6 decreased and the expression of CD36 increased after OA/PA induction compared to the control group, and these effects were reversed by the addition of csOCN. In contrast, the therapeutic effect of csOCN was inhibited by the addition of AMPK inhibitors and BCL6 inhibitors. This finding suggested that csOCN regulates CD36 expression via the AMPK-FOXO1/BCL6 axis. In NAFLD mice, oral administration of csOCN also activated the AMPK pathway and reduced CD36 expression. Molecular docking revealed that osteocalcin has a docking site with CD36. Compared to oleic acid and palmitic acid, osteocalcin bound more strongly to CD36. Laser confocal microscopy results showed that osteocalcin colocalized with CD36 at the cell membrane. In conclusion, we demonstrated the regulatory role of csOCN in fatty acid uptake pathways for the first time; it regulates CD36 expression via the AMPK-FOXO1/BCL6 axis to reduce fatty acid uptake, and it affects fatty acid transport by may directly binding to CD36. There are indications that csOCN has potential as a CD36-targeted drug for the treatment of NAFLD.

Diosgenin attenuates metabolic-associated fatty liver disease through the hepatic NLRP3 inflammasome-dependent signaling pathway

Metabolic-associated fatty liver disease (MAFLD) is one of the most common liver diseases worldwide; however, its pathogenesis and treatment methods have not been perfected. NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) is a promising therapeutic target for MAFLD. Diosgenin (DG) is a natural compound that was identified in a traditional Chinese herbal medicine, which has pharmacological effects, such as anti-inflammatory, antioxidant, hepatoprotective, and hypolipidemic activities. In this study, we examined the effects and molecular mechanisms of DG on MAFLD in vitro and in vivo. We established a rat model by administering a high-fat diet (HFD). We also generated an in vitro MAFLD model by treating HepG2 cells with free fatty acids (FFAs). The results indicated that DG attenuated lipid accumulation and liver injury in both in vitro and in vivo models. DG downregulated the expression of NLRP3, apoptosis-associated speckle-like protein (ASC), cysteinyl aspartate specific proteinase-1 (caspase-1), gasdermin D (GSDMD), GSDMD-n, and interleukin-1β (IL-1β). In addition, we silenced and overexpressed NLRP3 in vitro to determine the effects of DG on antiMAFLD. Silencing NLRP3 enhanced the effect of DG on the treatment of MAFLD, whereas NLRP3 overexpression reversed its beneficial effects. Taken together, the results show that DG has a favorable effect on attenuating MAFLD through the hepatic NLRP3 inflammasome-dependent signaling pathway. DG represents a natural NLRP3 inhibitor for the MAFLD treatment.

Hypocholesterolemic potential of Bacillus amyloliquefaciens KAVK1 modulates lipid accumulation on 3T3-L1 adipose cells and high fat diet-induced obese rat model.

The significance of microorganisms occurring in foods is predominantly targeted due to their application for identifying a novel range of the bacterial spectrum. Diverse microbial species are capable of exhibiting potential pharmacological activities like antimicrobial and anticancer. Microbial strains capable of reducing obesity-related syndromes have also been reported. In the present study, the hypocholesterolemic efficacy of Bacillus amyloliquefaciens isolated from dairy products was scrutinised by in vitro (3T3-L1 adipose cells) and in vivo (high-fat diet-induced obese Wistar albino rats) methods. Potential cholesterol-lowering isolates were screened using a plate assay method and optimised by physical parameters. Molecular identification of the topmost five cholesterol-lowering isolates was acquired by amplification of the 16S rRNA gene region. Bacillus amyloliquefaciens strain KAVK1, followed by strains KAVK2, KAVK3, KAVK4, and KAVK5 were molecularly determined. Further, cholesterol-lowering strains degraded the spectral patterns determined by the side chain of a cholesterol molecule. The anti-lipase activity was demonstrated using the porcine pancreatic lipase inhibitory method and compared with the reference compound Atorvastatin. Lyophilised strain KAVK1 revealed maximum pancreatic lipase inhibition. Strain KAVK1 attenuated lipid accumulation in 3T3-L1 adipose cell line predicted by Oil Red O staining method. Significant reduction of body weight and change in lipid profile was recognised after the supplement of KAVK1 to obese rats. Histopathological changes in organs were predominantly marked. The result of this study implies that the cholesterol-lowering B. amyloliquefaciens KAVK1 strain was used to treat hypercholesterolemia.

Lactucopicrin promotes fatty acid β-oxidation and attenuates lipid accumulation through adenosine monophosphate-activated protein kinase activation in free fatty acid-induced human hepatoblastoma cancer cells.

With its annually increasing prevalence, non-alcoholic fatty liver disease (NAFLD) has become a serious threat to people's life and health. After a preliminary research, we found that Lactucopicrin has pharmacological effects, such as lowering blood lipids and protecting the liver. Further research showed its significant activation for fatty acid β-oxidase hydroxyacyl-coenzyme A (CoA) dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA), so we hypothesized that Lactucopicrin could ameliorate lipid accumulation in hepatocytes by promoting fatty acid β-oxidation. In this study, free fatty acid (FFA)-induced human hepatoblastoma cancer cells (HepG2) were used to establish an invitro NAFLD model to investigate the molecular basis of Lactucopicrin in regulating lipid metabolism. Staining with Oil red O and measurements of triglyceride (TG) content, fatty acid β-oxidase (FaβO) activity, reactive oxygen species (ROS) content, mitochondrial membrane potential, and adenosine triphosphate (ATP) content were used to assess the extent to which Lactucopicrin ameliorates lipid accumulation and promotes fatty acid β-oxidation. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot methods were used to explore the regulatory effects of Lactucopicrin on factors related to fatty acid β-oxidation. Results showed that Lactucopicrin downregulated phosphorylated mammalian target of rapamycin (P-mTOR) by activating the adenosine monophosphate-activated protein kinase (AMPK) pathway and upregulated the messenger RNA (mRNA) and protein expression levels of coactivators (peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)), transcription factors (peroxisome proliferator-activated receptor α (PPARα) and peroxisome proliferator-activated receptor γ (PPARγ)), and oxidative factors (carnitine palmitoyltransferase 1A (CPT1A) and HADHA). This phenomenon resulted in a significant increase in FaβO activity, ATP content, and JC-1 and a significant decrease in ROS level, TG content, and intracellular lipid droplets. With the addition of Dorsomorphin, all the effects of Lactucopicrin intervention were suppressed. In summary, Lactucopicrin promotes fatty acid β-oxidation by activating the AMPK pathway, thereby ameliorating FFA-induced intracellular lipid accumulation in HepG2 cells.

Surfactant protein A promotes western diet-induced hepatic steatosis and fibrosis in mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) remains the most common cause of liver disease in the United States due to the increased incidence of metabolic dysfunction and obesity. Surfactant protein A (SPA) regulates macrophage function, strongly binds to lipids, and is implicated in renal and idiopathic pulmonary fibrosis (IPF). However, the role of SPA in lipid accumulation, inflammation, and hepatic fibrosis that characterize MASLD remains unknown. SPA deficient (SPA−/−) and age-matched wild-type (WT) control mice were fed a Western diet for 8 weeks to induce MASLD. Blood and liver samples were collected and used to analyze pathological features associated with MASLD. SPA expression was significantly upregulated in livers of mice with MASLD. SPA deficiency attenuated lipid accumulation along with downregulation of genes involved in fatty acid uptake and reduction of hepatic inflammation as evidenced by the diminished macrophage activation, decreased monocyte infiltration, and reduced production of inflammatory cytokines. Moreover, SPA−/− inhibited stellate cell activation, collagen deposit, and liver fibrosis. These results highlight the novel role of SPA in promoting fatty acid uptake into hepatocytes, causing excessive lipid accumulation, inflammation, and fibrosis implicated in the pathogenesis of MASLD.

Gypenoside XLIX alleviates acute liver injury: Emphasis on NF-κB/PPAR-α/NLRP3 pathways

Liver is one of the vital organs in the human body and liver injury will have a very serious impact on human damage. Gypenoside XLIX is a PPAR-α activator that inhibits the activation of the NF-κB signaling pathway. The components of XLIX have pharmacological effects such as cardiovascular protection, antihypoxia, anti-tumor and anti-aging. In this study, we used cecum ligation and puncture (CLP) was used to induce in vivo mice hepatic injury, and lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells, evaluated whether Gypenoside XLIX could have a palliative effect on sepsis-induced acute liver injury via NF-κB/PPAR-α/NLRP3. In order to gain insight into these mechanisms, six groups were created in vivo: the Contol group, the Sham group, the CLP group, the CLP + XLIX group (40 mg/kg) and the Sham + XLIX (40 mg/kg) group, and the CLP + DEX (2 mg/kg) group. Three groups were created in vitro: Control, LPS, LPS + XLIX (40 μM). The analytical methods used included H&E staining, qPCR, reactive oxygen species (ROS), oil red O staining, and Western Blot. The results showed that XLIX attenuated hepatic inflammatory injury in mice with toxic liver disease through inhibition of the TLR4-mediated NF-κB pathway, attenuated lipid accumulation through activation of PPAR-α, and attenuated hepatic pyroptosis by inhibiting NLRP3 production. Regarding the imbalance between oxidative and antioxidant defenses due to septic liver injury, XLIX reduced liver oxidative stress-related biomarkers (ALT, AST), reduced ROS accumulation, decreased the amount of malondialdehyde (MDA) produced by lipid peroxidation, and increased the levels of antioxidant enzymes such as glutathione (GSH) and catalase (CAT). Our results demonstrate that XLIX can indeed attenuate septic liver injury. This is extremely important for future studies on XLIX and sepsis, and provides a potential pathway for the treatment of acute liver injury.

Nobiletin alleviates atherosclerosis by inhibiting lipid uptake via the PPARG/CD36 pathway

BackgroundAtherosclerosis (AS) is a persistent inflammatory condition triggered and exacerbated by several factors including lipid accumulation, endothelial dysfunction and macrophages infiltration. Nobiletin (NOB) has been reported to alleviate atherosclerosis; however, the underlying mechanism remains incompletely understood.MethodsThis study involved comprehensive bioinformatic analysis, including multidatabase target prediction; GO and KEGG enrichment analyses for function and pathway exploration; DeepSite and AutoDock for drug binding site prediction; and CIBERSORT for immune cell involvement. In addition, target intervention was verified via cell scratch assays, oil red O staining, ELISA, flow cytometry, qRT‒PCR and Western blotting. In addition, by establishing a mouse model of AS, it was demonstrated that NOB attenuated lipid accumulation and the extent of atherosclerotic lesions.Results(1) Altogether, 141 potentially targetable genes were identified through which NOB could intervene in atherosclerosis. (2) Lipid and atherosclerosis, fluid shear stress and atherosclerosis may be the dominant pathways and potential mechanisms. (3) ALB, AKT1, CASP3 and 7 other genes were identified as the top 10 target genes. (4) Six genes, including PPARG, MMP9, SRC and 3 other genes, were related to the M0 fraction. (5) CD36 and PPARG were upregulated in atherosclerosis samples compared to the normal control. (6) By inhibiting lipid uptake in RAW264.7 cells, NOB prevents the formation of foam cell. (7) In RAW264.7 cells, the inhibitory effect of oxidized low-density lipoprotein on foam cells formation and lipid accumulation was closely associated with the PPARG signaling pathway. (8) In vivo validation showed that NOB significantly attenuated intra-arterial lipid accumulation and macrophage infiltration and reduced CD36 expression.ConclusionsNobiletin alleviates atherosclerosis by inhibiting lipid uptake via the PPARG/CD36 pathway.

Coffee pulp simulated digestion enhances its in vitro ability to decrease emulsification and digestion of fats, and attenuates lipid accumulation in HepG2 cell model

The coffee industry produces a considerable quantity of coffee pulp (CP), a by-product with high levels of caffeine, phenolic compounds, and dietary fiber, which are reportedly involved in the lipid homeostasis regulation required to maintain human health. This work's objective was to evaluate the hypolipidemic activity of coffee pulp flour (CPF) and aqueous extract (CPE) after static simulated digestion by the assessment of their in vitro capacity to decrease emulsification and digestion of fats, and lipid-lowering capacity in HepG2 cells after the induction of intracellular fat accumulation. The CPF and CPE digested fractions displayed in vitro hypolipidemic properties by preserving the reduction of micellar cholesterol solubility (27–34%) and the secondary bile acid-binding capacity (22–30%), increasing their primary bile acid-binding ability (2.7-fold and 2.4-fold, respectively), and inhibiting the lipase and the HMGCR (77–79% and 36–85%, respectively) activities. Moreover, the hypolipidemic properties of non-digested fractions enhanced the CPF potential to decrease lipid absorption. Both ingredients (CPF and CPE) demonstrated lipid-lowering effects since they effectively counteract the accumulation of intracellular triglycerides and cholesterol triggered by palmitic acid in hepatic cells after the simulated digestion. This study suggests that phenolic compounds, caffeine, and dietary fiber may be responsible for the lipid-lowering properties exhibited by the CP ingredients and their composition differences affect the above-mentioned properties exhibited in the simulated digestion. These results contribute to demonstrating that the CPF and the CPE may act as modulators of pathways involved in hepatic lipid accumulation and could be a key element in its prevention.

Icariside II prevents kidney fibrosis development in chronic kidney disease by promoting fatty acid oxidation.

Renal interstitial fibrosis (RIF) is the main pathological basis for the progression of chronic kidney disease (CKD), however, effective interventions are limited. Here, we investigated the effect of Icariside II (ICA-II) on RIF and explored the underlying mechanisms. Rats receiving 5/6 ablation and infarction (A/I) surgery were gavaged with ICA-II (5 or 10 mg/kg) for 8 weeks. In vitro, TGF-β1-stimulated NRK-52E cells were treated with ICA-II and (or) oleic acid, etomoxir, ranolazine, fenofibrate, and GW6471. The effects of ICA-II on RIF, fatty acid oxidation, lipid deposition, and mitochondrial function were determined by immunoblotting, Oil red O staining, colorimetric, and fluorometric assays. Using adeno-associated virus injection and co-culture methods, we further determined mechanisms of ICA-II anti-RIF. ICA-II ameliorated the fibrotic responses in vivo and in vitro. RNA-seq analysis indicated that ICA-II regulated fatty acid degradation and PPAR pathway in 5/6 (A/I) kidneys. ICA-II attenuated lipid accumulation and up-regulated expression of PPARα, CPT-1α, Acaa2, and Acadsb proteins in vivo and in vitro. Compared to ICA-II treatment, ICA-II combined with Etomoxir exacerbated mitochondrial dysfunction and fibrotic responses in TGF-β-treated NRK-52E cells. Importantly, we determined that ICA-II improved lipid metabolism, fatty acid oxidation, mitochondrial function, and RIF by restoring PPARα. Co-culture revealed that ICA-II decreased the expression of Fibronectin, Collagen-I, α-SMA, and PCNA proteins in NRK-49F cells by restoring PPARα of renal tubular cells. ICA-II may serve as a promising therapeutic agent for RIF in 5/6 (A/I) rats, which may be important for the prevention and treatment of CKD.

Foxa2 attenuates steatosis and inhibits the NF-κB/IKK signaling pathway in nonalcoholic fatty liver disease

Objective Forkhead box a2 (Foxa2) is proven to be an insulin-sensitive transcriptional regulator and affects hepatic steatosis. This study aims to investigate the mechanism by which Foxa2 affects nonalcoholic fatty liver disease (NAFLD). Methods Animal and cellular models of NAFLD were constructed using high-fat diet (HFD) feeding and oleic acid (OA) stimulation, respectively. NAFLD mice received tail vein injections of either an overexpressing negative control (oe-NC) or Foxa2 (oe-Foxa2) for four weeks. HepG2 cells were transfected with oe-NC and oe-Foxa2 for 48 h before OA stimulation. Histological changes and lipid accumulation were assessed using hematoxylin-eosin staining and oil red O staining, respectively. Expression of Foxa2, NF-κB/IKK pathway proteins, lipid synthesis proteins, and fatty acid β-oxidation protein in HFD mice and OA-induced HepG2 cells was detected using western blot. Results Foxa2 expression was downregulated in HFD mice and OA-induced HepG2 cells. Foxa2 overexpression attenuated lipid accumulation and liver injury, and reduced the levels of aspartate aminotransferase, alanine aminotransferase, total cholesterol, or triglyceride in HFD mice and OA-induced HepG2 cells. Moreover, Foxa2 overexpression decreased the expression of lipid synthesis proteins and increased fatty acid β-oxidation protein expression in the liver tissues. Furthermore, overexpression of Foxa2 downregulated the expression of p-NF-κB/NF-κB and p-IKK/IKK in OA-induced HepG2 cells. Additionally, lipopolysaccharide (NF-κB/IKK pathway activator) administration reversed the downregulation of lipid synthesis proteins and the upregulation of fatty acid β-oxidation protein. Conclusion Foxa2 expression is downregulated in NAFLD. Foxa2 ameliorated hepatic steatosis and inhibited the activation of the NF-κB/IKK signaling pathway.

In Vitro Assessment of Anti-Adipogenic and Anti-Inflammatory Properties of Black Cumin (Nigella sativa L.) Seeds Extract on 3T3-L1 Adipocytes and Raw264.7 Macrophages.

Background and Objectives: This study evaluated the in vitro anti-adipogenic and anti-inflammatory properties of black cumin (Nigella sativa L.) seed extract (BCS extract) as a potential candidate for developing herbal formulations targeting metabolic disorders. Materials and Methods: We evaluated the BCS extract by assessing its 2,2-diphenyl-1-picrohydrazyl (DPPH) radical scavenging activity, levels of prostaglandin E2 (PGE2) and nitric oxide (NO), and mRNA expression levels of key pro-inflammatory mediators. We also quantified the phosphorylation of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) and mitogen-activated protein kinases (MAPK) signaling molecules. To assess anti-adipogenic effects, we used differentiated 3T3-L1 cells and BCS extract in doses from 10 to 100 μg/mL. We also determined mRNA levels of key adipogenic genes, including peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein α (C/BEPα), adipocyte protein 2 (aP2), lipoprotein lipase (LPL), fatty acid synthase (FAS), and sterol-regulated element-binding protein 1c (SREBP-1c) using real-time quantitative polymerase chain reaction (qPCR). Results: This study showed a concentration-dependent DPPH radical scavenging activity and no toxicity at concentrations up to 30 μg/mL in Raw264.7 cells. BCS extract showed an IC50 of 328.77 ± 20.52 μg/mL. Notably, pre-treatment with BCS extract (30 μg/mL) significantly enhanced cell viability in lipopolysaccharide (LPS)-treated Raw264.7 cells. BCS extract treatment effectively inhibited LPS-induced production of PGE2 and NO, as well as the expression of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), inducible NO synthase (iNOS), interleukin (IL)-1β and IL-6, possibly by limiting the phosphorylation of p38, p65, inhibitory κBα (I-κBα), and c-Jun N-terminal kinase (JNK). It also significantly attenuated lipid accumulation and key adipogenic genes in 3T3-L1 cells. Conclusions: This study highlights the in vitro anti-adipogenic and anti-inflammatory potential of BCS extract, underscoring its potential as a promising candidate for managing metabolic disorders.