2-Geranyl-1-methoxyerythrabyssin II alleviates lipid accumulation and inflammation in hepatocytes through AMPK activation and AKT inhibition.

A growing proportion of the global adult and pediatric populations are currently affected by nonalcoholic steatohepatitis (NASH), leading to rising rates of liver fibrosis and hepatocellular carcinoma without effective pharmacotherapy. Here, we investigated whether 2-geranyl-1-methoxyerythrabyssin II (GMET), isolated from Lespedeza bicolor, could alleviate lipid accumulation and inflammatory responses in a NASH model. GMET exhibited potent in vitro and in vivo effects against lipid accumulation and attenuated inflammatory responses without cytotoxicity. Mechanistically, GMET inhibits acetyl-CoA carboxylase (ACC), sterol regulatory element-binding proteins-1c (SREBP1), and mammalian target of rapamycin (mTOR), and activates PPARα by activating AMP-activated kinase (AMPK), leading to the alleviation of lipid accumulation. In addition, GMET suppresses the NF-κB pathway by activating AMPK and inhibiting the activated protein kinase B (AKT)/IκB-kinase (IKK) pathway, leading to the inhibition of the inflammatory response in hepatocytes. All these protective effects of GMET on lipid accumulation and inflammation in vivo and in vitro were largely abolished by co-treatment with dorsomorphin, an AMPK inhibitor. In conclusion, GMET alleviated lipid accumulation and inflammation to preserve normal hepatocyte function in steatohepatitis. Thus, GMET is a novel potential multi-targeting compound to improve steatohepatitis.

Plumbagin relieves rheumatoid arthritis through nuclear factor kappa-B (NF-κB) pathway.

This study aimed to explore the effects of plumbagin on rheumatoid arthritis (RA) and its mechanism. The RA cell model was simulated following the treatment of interleukin-1ß (IL-1ß). After the treatment of various concentrations of plumbagin, the impact of plumbagin on the cell viability was examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The collagen-induced arthritis (CIA) model was established using the solution of bovine type II collagen. Hematoxylin-eosin staining was used to observe the changes of ankle joint tissue, while enzyme-linked immunosorbent assay and western blot were applied to detect the level of inflammatory cytokines. Plumbagin inhibited the viability of human fibroblast-like synoviocytes (HFLS) at the concentration of 1 ~ 3.5 µM. The inhibitory effect of 1 µM plumbagin on cell proliferation was similar to that of methotrexate, the drug used as the positive control. Plumbagin downregulated the levels of inflammatory cytokines and matrix metalloproteinases (MMPs) in IL-1ß-treated HFLS, and suppressed the activation of IκB and nuclear factor kappa-B (NF-κB) as well as the entry of p65 into the nucleus. It was also demonstrated in animal experiments that plumbagin inhibited the activation of NF-κB pathway, down-regulated the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and MMPs, and alleviated joint damage in CIA-modeled mice. Collectively speaking, plumbagin might down-regulate the levels of inflammatory cytokines and MMPs through inhibiting the activation of the NF-κB pathway, thereby attenuating RA-induced damage to cells and joints.Abbreviations: CIA: Collagen-induced arthritis; ELISA: Enzyme-linked immuno sorbent assay; HFLS: Human fibroblast-like synoviocytes; IL-6: Interleukin-6; IL-1ß: Interleukin-1ß; NF-κB: nuclear factor kappa-B; MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MMPs: Matrix metalloproteinase; OD: Optical density; RA: Rheumatoid arthritis; SDS: Sodium dodecyl sulfate; SD: Standard deviation; TNF-α: Tumor necrosis factor-α; PVDF: Polyvinylidene fluoride.

Chidamide Suppresses the Growth of Cholangiocarcinoma by Inhibiting HDAC3 and Promoting FOXO1 Acetylation.

Inhibitors for histone deacetylases (HDACs) have been identified as epigenetic drug targets to treat a variety of malignancies through several molecular mechanisms. The present study is aimed at investigating the mechanism underlying the possible antitumor effect of the HDAC inhibitor chidamide (CDM) on cholangiocarcinoma (CCA). Microarray-based gene expression profiling was conducted to predict the expression of HDACs in CCA, which was validated in clinical tissue samples from CCA patients. Next, the proliferation, migration, invasion, autophagy, and apoptosis of human CCA QBC939 and SNU308 cells were measured following treatment with CDM at different concentrations. The acetylation level of FOXO1 in the nucleus and cytoplasm of QBC939 and SNU308 cells was determined after overexpression and suppression of HDAC3. A QBC939-implanted xenograft nude mouse model was established for further exploration of CDM roles in vitro. HDAC3 was prominently expressed in CCA tissues and indicated a poor prognosis for patients with CCA. CDM significantly inhibited cell proliferation, migration, and invasion of QBC939 and SNU308 cells, while inducing their autophagy and apoptosis by reducing the expression of HDAC3. CDM promoted FOXO1 acetylation by inhibiting HDAC3, thereby inducing cell autophagy. Additionally, CDM inhibited tumor growth in vivo via HDAC3 downregulation and FOXO1 acetylation induction. Overall, this study reveals that CDM can exhibit antitumor effects against CCA by promoting HDAC3-mediated FOXO1 acetylation, thus identifying a new therapeutic avenue for the treatment of CCA.

Phytochemical investigation of the fruits of Xanthium strumarium and their cytotoxic activity.

Eight pentacyclic triterpenoids including two new ones (1, 2) were isolated from the fruits of Xanthium strumarium. Their structures were elucidated by extensive spectroscopic analysis. All isolates were evaluated for in vitro cytotoxic activity on HepG2, A549, HCT116 and SW480 cancer cells. Among them, the new compound 2 was found to exhibit significant cytotoxic activity on A549, HCT116 and SW480 cancer cells with IC50 values of 9.68, 4.27 and 7.58 µM, respectively. Further, 2 was selected for cell cycle analysis and results revealed that 2 could cause HCT116 cell cycle arrest in G1 phase. In addition, Annexin V-FITC/PI staining assay showed that 2 could induce the death of HCT116 cells.

New flavonoid glycosides from Xanthium strumarium with their protein tyrosine phosphatase 1B inhibitory activity.

Two new flavonoid glycosides named 6-hydroxy-3-methoxy-apigenin 7-O-α-ʟ-rhamnopyranoside (1) and 3-hydroxyl-apigenin 8-C-ß-ᴅ-xylopyranoside (2), along with five known compounds (3-7), were isolated from Xanthium strumarium. Their structures were elucidated on the basis of spectroscopic and physicochemical analyses. All compounds were evaluated for in vitro inhibitory activity against PTP1B. Among them, compounds 1 and 5 showed significant inhibitory activity on PTP1B with IC50 values of 11.3 ± 1.7 and 8.9 ± 0.7 µM, respectively.

(+)-Dehydrovomifoliol Alleviates Oleic Acid-Induced Lipid Accumulation in HepG2 Cells via the PPARα-FGF21 Pathway.

An overload of hepatic fatty acids, such as oleic acid is a key trigger of non-alcoholic fatty liver disease (NAFLD). Here, we investigated whether Artemisia frigida, a valuable traditional medicine used to treat various diseases, could mitigate OA-induced lipid accumulation in HepG2 cells. Then, to identify the active substances in A. frigida, a phytochemistry investigation was conducted using a bioassay-guided isolation method. Consequently, one terpene (1) and one flavone (2) were identified. Compound 1 ((+)-dehydrovomifoliol) exhibited potent effects against lipid accumulation in OA-induced HepG2 cells, without causing cyto-toxicity. Notably, treatment with (+)-dehydrovomifoliol decreased the expression levels of three genes related to lipogenesis (SREBP1, ACC, and FASN) and increased those of three genes related to fatty acid oxidation (PPARα, ACOX1, and FGF21). In addition, similar results were observed for SREBP1, PPARα, and FGF21 protein levels. The effects of (+)-dehydrovomifoliol were partially reversed by treatment with the PPARα antagonist GW6471, indicating the important role of the PPARα-FGF21 axis in the effects of (+)-dehydrovomifoliol. Based on its effects on hepatic lipogenesis and fatty acid oxidation signaling via the PPARα-FGF21 axis, (+)-dehydrovomifoliol isolated from A. frigida could be a useful early lead compound for developing new drugs for NAFLD prevention.

Resveratrol Alleviates Dextran Sulfate Sodium-Induced Acute Ulcerative Colitis in Mice by Mediating PI3K/Akt/VEGFA Pathway.

Ulcerative colitis (UC) is a chronic inflammatory disease that affects the colon, and its incidence is on the rise worldwide. Resveratrol (RSV), a polyphenolic compound, was recently indicated to exert anti-inflammatory effects on UC. Consequently, the current study was conducted to investigate the mechanism of RSV on alleviating UC in mice by mediating intestinal microflora homeostasis. First, potential targets that RSV may regulate UC were screened using the TCMSP database. Next, mice were treated differently, specifically subjected to sham-operation and dextran sulfate sodium (DSS) induction, and then treated or untreated with RSV. Disease Activity Index (DAI) and Hematoxylin-Eosin (HE) staining were employed to analyze the pathological changes of mice colon. In addition, the expression patterns of inflammatory factors in spleen tissues were detected using ELISA, while the protein expression patterns of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and vascular endothelial growth factor A (VEGFA) in colon tissues were determined by means of immunohistochemistry (IHC) and Western blot analysis. Moreover, changes in intestinal flora and metabolite diversity in UC were analyzed by metabonomics. It was found that RSV played inhibitory roles in the PI3K/Akt pathway in mice. Meanwhile, the administration of RSV induced downregulated the expressions of TNF-α, IFN-γ, IL-1ß, IL-6, and IL-4. The six floras of Haemophilus and Veillonella were significantly enriched in UC, while Clostridium, Roseburia, Akkermansia, and Parabacteroides were found to be enriched in control samples. Lastly, it was noted that Akkermansia could regulate the intestinal flora structure of UC mice through triacylglycerol biosynthesis, glycerol phosphate shuttle, cardiolipin biosynthesis, and other metabolic pathways to improve UC in mice. Altogether, our findings indicate that RSV suppressed the activation of the PI3K/Akt pathway and reduced the VEGFA gene expression to alleviate UC in mice.

Pancreatic fibroblast growth factor 21 protects against type 2 diabetes in mice by promoting insulin expression and secretion in a PI3K/Akt signaling-dependent manner.

Fibroblast growth factor 21 (FGF21) is important in glucose, lipid homeostasis and insulin sensitivity. However, it remains unknown whether FGF21 is involved in insulin expression and secretion that are dysregulated in type 2 diabetes mellitus (T2DM). In this study, we found that FGF21 was down-regulated in pancreatic islets of db/db mice, a mouse model of T2DM, along with decreased insulin expression, suggesting the possible involvement of FGF21 in maintaining insulin homeostasis and islet ß-cell function. Importantly, FGF21 knockout exacerbated palmitate-induced islet ß-cell failure and suppression of glucose-stimulated insulin secretion (GSIS). Pancreatic FGF21 overexpression significantly increased insulin expression, enhanced GSIS, improved islet morphology and reduced ß-cell apoptosis in db/db mice. Mechanistically, FGF21 promoted expression of insulin gene transcription factors and soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, the major regulators of insulin secretion, as well as activating phosphatidylinositol 3-kinase (PI3K)/Akt signaling in islets of db/db mice. In addition, pharmaceutical inhibition of PI3K/Akt signaling effectively suppressed FGF21-induced expression of insulin gene transcription factors and SNARE proteins, suggesting an essential role of PI3K/Akt signaling in FGF21-induced insulin expression and secretion. Taken together, our results demonstrate a protective role of pancreatic FGF21 in T2DM mice through inducing PI3K/Akt signaling-dependent insulin expression and secretion.

FGF21 Prevents Angiotensin II-Induced Hypertension and Vascular Dysfunction by Activation of ACE2/Angiotensin-(1-7) Axis in Mice.

Fibroblast growth factor 21 (FGF21) is a metabolic hormone with pleiotropic effects on glucose and lipid metabolism and insulin sensitivity. However, the role of FGF21 in hypertension remains elusive. Here we show that FGF21 deficiency significantly exacerbates angiotensin II-induced hypertension and vascular dysfunction, whereas such negative effects are reversed by replenishment of FGF21. Mechanistically, FGF21 acts on adipocytes and renal cells to promote induction of angiotensin-converting enzyme 2 (ACE2), which in turn converts angiotensin II to angiotensin-(1-7), then inhibits hypertension and reverses vascular damage. In addition, ACE2 deficiency strikingly abrogates these beneficial effects of FGF21 in mice, including alleviation of angiotensin II-associated hypertension and vascular damage. Otherwise, pharmaceutical inhibition of angiotensin-(1-7) attenuates the protective effect of FGF21 on angiotensin II-induced vascular dysfunction, but not on hypertension. Thus, FGF21 protects against angiotensin II-induced hypertension and vascular impairment by activation of the ACE2/angiotensin-(1-7) axis via fine-tuning the multi-organ crosstalk between liver, adipose tissue, kidney, and blood vessels.

FGF21 mediates the protective effect of fenofibrate against acetaminophen -induced hepatotoxicity via activating autophagy in mice.

Overdose of acetaminophen (APAP) induces acute liver injury due in part to destruction of mitochondria and resulted oxidative stress. Recently, FGF21 has been demonstrated to be an endocrine factor to protect liver from oxidative stress. The aim of present study is to explore the role of fibroblast growth factor 21 (FGF21) in the protective effect of fenofibrate, an agonist of peroxisome proliferator-activated receptor alpha (PPARα), against acetaminophen (APAP)-induced liver injury. Mice and primary cultured hepatocytes were used to test the potential hepatoprotective effect of fenofibrate against APAP-induced hepatotoxicity. FGF21 deficient mice were used to evaluate the role of FGF21 in fenofibrate against APAP-induced acute liver injury. Post-treatment with fenofibrate significantly inhibits APAP-induced hepatotoxicity, as evidenced by decreased serum ALT and AST levels and hepatic necrosis in liver tissue as well as increased the surviving rate in response to APAP overdose, whereas this protective effect of fenofibrate is largely attenuated in FGF21 KO mice. Interestingly, administration of fenofibrate efficiently increases autophagy, which was companied with alleviating hepatotoxicity in APAP-treated WT mice. However, such effect is significantly attenuated in APAP-treated FGF21 KO mice. In conclusion, our findings suggest that fenofibrate against APAP-induced hepatotoxicity is at least in part mediated by up-regulating the expression of FGF21, which in turn promotes autophagy-mediated hepatoprotective effects.

CXCL16 deficiency attenuates diabetic nephropathy through decreasing oxidative stress and inflammation.

Soluble C-X-C chemokine ligand 16 (CXCL16) is related to the inflammatory response in liver injury and involved in the pathogenesis of renal dysfunction in diabetes patients. However, the exact role of elevated CXCL16 in diabetic nephropathy (DN) remains unclear. In this study, we investigated the role of CXCL16 in streptozcin (STZ)-induced diabetic nephropathy (DN) in mice. The results showed that fasting blood glucose (FBG) and 24 h urinary protein, triglyceride, and cholesterol levels increased in diabetic mice, and these changes were partially ameliorated in CXCL16 KO mice. Meanwhile, the results also showed that ROS generation was suppressed and the expression levels of inflammatory factors and infiltration factors were inhibited both in vivo and in vitro using DN models. In addition, the total AKT protein and p-AKT levels were decreased in CXCL16-depleted HK-2 cells that were treated with LPS. These findings suggest that the CXCL16 gene product promotes inflammatory factors and cell infiltration factors, and inhibits the expression of antioxidant factors to accelerate the development of DN, and CXCL16 deficiency attenuates DN may be involved in the AKT signaling pathway.