Echinacoside improves diabetic liver injury by regulating the AMPK/SIRT1 signaling pathway in db/db mice

Echinacoside Exerts Antihepatic Fibrosis Effects in High-Fat Mice Model by Modulating the ACVR2A-Smad Pathway

SCOPE

Nonalcoholic steatohepatitis (NASH) is an increasingly common chronic liver disease in which hepatic fibrosis is the major pathological change. The transforming growth factor β (TGF-β)/mall mothers against decapentaplegic (Smad) signaling is the main effector of fibrosis. Although the antifibrotic effect of echinacoside (Ech) on the liver has been indicated previously, the cellular and molecular mechanisms remain unclear. This study aims to investigate both in vivo and in vitro antifibrotic properties of Ech.

METHODS AND RESULTS

Cell viability and scratch/wound assays show that Ech significantly inhibits the proliferation, migration, and activation of human hepatic stellate LX-2 cells. In mice with high-fat diet-induced hepatic fibrosis, Ech treatment attenuates the progression of liver injury, inflammation, and fibrosis. Furthermore, transcriptome analysis and subsequent functional validation demonstrate that Ech achieves antifibrotic effects by the activin receptor type-2A (ACVR2A)-mediated TGF-β1/Smad signaling pathway; ultimately, ACVR2A is demonstrated to be an important target for hepatic fibrosis by inhibiting and inducing the expression of ACVR2A in LX-2 cells.

CONCLUSION

Ech exerts potent antifibrotic effects by inhibiting the ACVR2A-mediated TGF-β1/Smad signaling axis and may serve as an alternative treatment for hepatic fibrosis.

Sirtuin1 Mediates the Protective Effects of Echinacoside against Sepsis-Induced Acute Lung Injury via Regulating the NOX4-Nrf2 Axis

Currently, the treatment for sepsis-induced acute lung injury mainly involves mechanical ventilation with limited use of drugs, highlighting the urgent need for new therapeutic options. As a pivotal aspect of acute lung injury, the pathologic activation and apoptosis of endothelial cells related to oxidative stress play a crucial role in disease progression, with NOX4 and Nrf2 being important targets in regulating ROS production and clearance. Echinacoside, extracted from the traditional Chinese herbal plant Cistanche deserticola, possesses diverse biological activities. However, its role in sepsis-induced acute lung injury remains unexplored. Moreover, although some studies have demonstrated the regulation of NOX4 expression by SIRT1, the specific mechanisms are yet to be elucidated. Therefore, this study aimed to investigate the effects of echinacoside on sepsis-induced acute lung injury and oxidative stress in mice and to explore the intricate regulatory mechanism of SIRT1 on NOX4. We found that echinacoside inhibited sepsis-induced acute lung injury and oxidative stress while preserving endothelial function. In vitro experiments demonstrated that echinacoside activated SIRT1 and promoted its expression. The activated SIRT1 was competitively bound to p22 phox, inhibiting the activation of NOX4 and facilitating the ubiquitination and degradation of NOX4. Additionally, SIRT1 deacetylated Nrf2, promoting the downstream expression of antioxidant enzymes, thus enhancing the NOX4-Nrf2 axis and mitigating oxidative stress-induced endothelial cell pathologic activation and mitochondrial pathway apoptosis. The SIRT1-mediated anti-inflammatory and antioxidant effects of echinacoside were validated in vivo. Consequently, the SIRT1-regulated NOX4-Nrf2 axis may represent a crucial target for echinacoside in the treatment of sepsis-induced acute lung injury.

Echinacoside exerts its protective effects in a type 2 diabetes mellitus injury model via the AKT pathway

Echinacoside (ECH) is the main compound of Cistanche deserticola, which possesses antioxidant, antitumor, antifatigue, and anti-inflammatory properties. The present study investigated the protective effects of echinacoside on type 2 diabetes mellitus (T2DM)-induced injury in T2DM injury db/db mice model and insulin-resistant LO2 cell model. The results demonstrated that ECH probably alleviated T2DM-induced injury by mediating the AKT pathway, which provided a new direction for the treatment of T2DM-induced injury.

Cymbaria daurica L.: A Mongolian herbal medicine for treating eczema via natural killer cell-mediated cytotoxicity pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cymbaria daurica L. (C. daurica) is a perennial herb known commonly as "Xinba" (Chinese) and "Kanba-Arong" (Mongolian). In Mongolia, it is used as a traditional medicine to treat eczema and other skin diseases due to its anti-swelling, anti-inflammatory, anti-hemorrhagic, and anti-itching properties. However, the potential mechanism of action for eczema treatment has not been reported.

AIM OF THE STUDY

To investigate the effect of C. daurica on 1-chloro-2,4-dinitrobenzene (DNCB)-induced eczema in rats and the associated action mechanism.

MATERIALS AND METHODS

Qualitative analysis of C. daurica was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on information obtained from compound identification and relevant literature, the possible targets of C. daurica against eczema were analyzed using network pharmacology and molecular docking methods. The DNCB-induced eczema rat models were treated with different dosages of C. daurica extract (10, 50, and 250 mg/mL per day), and the therapeutic effects subsequently evaluated based on the degree of skin inflammation, spleen index, and hematoxylin and eosin staining (H&E staining). Enzyme-linked immunosorbent assay (ELISA), reverse transcription quantitative polymerase chain reaction (RT-qPCR), and western blotting were used to analyze the relevant target effects. The C. daurica mechanism of action on eczema was verified by animal experiments. High-performance liquid chromatography (HPLC) was carried out to determine the content of active ingredients in C. daurica. In addition, the physicochemical properties of the extract were evaluated.

RESULTS

Our analysis of the 173 targets included in the protein-protein interaction (PPI) network identified tumor necrosis factor (TNF) and interleukin 2 (IL-2) as key targets involved in the treatment of eczema with C. daurica extract. Furthermore, the 173 targets were associated with the natural killer cell-mediated cytotoxicity pathway. Our results showed that C. daurica significantly reduced IL-2 and TNF-α serum levels in eczema rat models (P < 0.0001); thus, playing an important role in the anti-inflammatory response. Furthermore, according to the p-value, RT-qPCR and western blotting showed that the expression of Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1), Vav guanine nucleotide exchange factor (Vav), and growth factor receptor-bound protein 2 (Grb2) changed in the skin of the eczema model rats after treatment with the C. daurica extract.

CONCLUSION

Our study confirms that C. daurica can inhibit SHP-1, Vav, and Grb2 expression; thereby, inhibiting the natural killer cell-mediated cytotoxicity pathway. These results provide insight into the mechanism of C. daurica in treating eczema.

Echinacoside from Cistanche tubulosa ameliorates alcohol-induced liver injury and oxidative stress by targeting Nrf2

Cistanche tubulosa (Schrenk) Wight, named Guan hua Rou Cong-Rong in Chinese, is a traditional plant with liver, kidney, and intestine protective effects. Echinacoside (ECH) is its active constituent and has been found to have various biological effects, including antioxidative stress and anti-inflammatory effects. Liver injury caused by acetaminophen or CCL₄ has been proven to benefit from ECH; however, the effects of ECH against alcoholic liver disease (ALD) remain unclear. This study was used to estimate the effect of echinacoside on nuclear factor erythroid 2-related factor 2 (Nrf2), which ameliorates ALD by inhibiting oxidative stress and cell apoptosis through affecting Nrf2.A mouse model of ALD was established with ethanol using hematoxylin and eosin (HE) staining, oiled staining, and biochemical indices. Alpha Mouse Liver 12 (AML-12) cells were induced with ethanol in vitro and analyzed using western blotting, flow cytometry, and biochemical assays. In the animal model of ALD, ECH dramatically reduced liver damage, as proven by the downregulation of aspartate aminotransferase (AST) and HE staining. In vitro, ECH distinctly reduced the damage caused by ethanol through the decreased expression of cleaved caspase-3 measured by western blotting. ECH significantly increased the activity of Nrf2 in vivo and in vitro. Nrf2 knockout may diminish the influence of ECH on ALD. Meanwhile, ECH also increased the expression of haem oxygenase-1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC), while it inhibited levels of oxidative stress and cell apoptosis. Our findings suggest that ECH protects against ethanol-induced liver injuries by alleviating oxidative stress and cell apoptosis by increasing the activity of Nrf2. Therefore, ECH is promising for the treatment of ALD.

Ginsenosides Restore Lipid and Redox Homeostasis in Mice with Intrahepatic Cholestasis through SIRT1/AMPK Pathways

Intrahepatic cholestasis (IC) occurs when the liver and systemic circulation accumulate bile components, which can then lead to lipid metabolism disorders and oxidative damage. Ginsenosides (GS) are pharmacologically active plant products derived from ginseng that possesses lipid-regulation and antioxidation activities. The purpose of this study was to evaluate the possible protective effects of ginsenosides (GS) on lipid homeostasis disorder and oxidative stress in mice with alpha-naphthylisothiocyanate (ANIT)-induced IC and to investigate the underlying mechanisms. A comprehensive strategy via incorporating pharmacodynamics and molecular biology technology was adopted to investigate the therapeutic mechanisms of GS in ANIT-induced mice liver injury. The effects of GS on cholestasis were studied in mice that had been exposed to ANIT-induced cholestasis. The human HepG2 cell line was then used in vitro to investigate the molecular mechanisms by which GS might improve IC. The gene silencing experiment and liver-specific sirtuin-1 (SIRT1) knockout (SIRT1^LKO) mice were used to further elucidate the mechanisms. The general physical indicators were assessed, and biological samples were collected for serum biochemical indexes, lipid metabolism, and oxidative stress-related indicators. Quantitative PCR and H&E staining were used for molecular and pathological analysis. The altered expression levels of key pathway proteins (Sirt1, p-AMPK, Nrf2) were validated by Western blotting. By modulating the AMPK protein expression, GS decreased hepatic lipogenesis, and increased fatty acid β-oxidation and lipoprotein lipolysis, thereby improving lipid homeostasis in IC mice. Furthermore, GS reduced ANIT-triggered oxidative damage by enhancing Nrf2 and its downstream target levels. Notably, the protective results of GS were eliminated by SIRT1 shRNA in vitro and SIRT1^LKO mice in vivo. GS can restore the balance of the lipid metabolism and redox in the livers of ANIT-induced IC models via the SIRT1/AMPK signaling pathway, thus exerting a protective effect against ANIT-induced cholestatic liver injury.

A pair of novel phenylethanol glycosides from Cistanche tubulosa (Schenk) Wight

A pair of differential epimers with opposite C-7 configurations, crenatosides A and B (1 and 2), and 10 known phenylethanoid glycosides (PhGs) (3-12) were obtained from the succulent stem of Cistanche tubulosa. The structures were elucidated based on extensive spectral data (UV, IR, 1D and 2D NMR, HR-ESIMS), which are first reported natural products with unique glycoside structures. After acid hydrolysis, the configuration of the sugar was determined by comparing it with the normative sugar by HPLC. The absolute configurations of both compounds were determined by ECD spectrum analysis. All the obtained compounds were examined for their inhibitory effect on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse microglial cells (BV-2 cells), and compounds 1 and 2 showed potent inhibition on NO production with IC₅₀ values of 5.62 μM and 6.30 μM, respectively.

AMPK signaling in diabetes mellitus, insulin resistance and diabetic complications: A pre-clinical and clinical investigation

Diabetes mellitus (DM) is considered as a main challenge in both developing and developed countries, as lifestyle has changed and its management seems to be vital. Type I and type II diabetes are the main kinds and they result in hyperglycemia in patients and related complications. The gene expression alteration can lead to development of DM and related complications. The AMP-activated protein kinase (AMPK) is an energy sensor with aberrant expression in various diseases including cancer, cardiovascular diseases and DM. The present review focuses on understanding AMPK role in DM. Inducing AMPK signaling promotes glucose in DM that is of importance for ameliorating hyperglycemia. Further investigation reveals the role of AMPK signaling in enhancing insulin sensitivity for treatment of diabetic patients. Furthermore, AMPK upregulation inhibits stress and cell death in β cells that is of importance for preventing type I diabetes development. The clinical studies on diabetic patients have shown the role of AMPK signaling in improving diabetic complications such as brain disorders. Furthermore, AMPK can improve neuropathy, nephropathy, liver diseases and reproductive alterations occurring during DM. For exerting such protective impacts, AMPK signaling interacts with other molecular pathways such as PGC-1α, PI3K/Akt, NOX4 and NF-κB among others. Therefore, providing therapeutics based on AMPK targeting can be beneficial for amelioration of DM.

Cinnamic Acid Ameliorates Nonalcoholic Fatty Liver Disease by Suppressing Hepatic Lipogenesis and Promoting Fatty Acid Oxidation

BACKGROUND

Cinnamic acid (CA) has been shown to have many beneficial effects including regulating lipid metabolism and reducing obesity. However, its effect on nonalcoholic fatty liver disease (NAFDL) has not been investigated in detail. Thus, we performed this study in order to explore CA's effect on hepatic lipid metabolism and the underlying mechanisms.

METHOD

Oleic acid (OA) was used to induce lipid accumulation in HepG2 cells. After coincubation with CA, the cells were stained with oil red O and the triglyceride (TG) content was assessed. Key genes in lipogenesis and fatty acid oxidation pathways were tested. Additionally, db/db and wt/wt mice were divided into three groups, with the wt/wt mice representing the normal group and the db/db mice being divided into the NAFLD and CA groups. After 4 weeks of oral treatment, all mice were sacrificed and the blood lipid profile and liver tissues were assessed.

RESULTS

CA treatment reduced the lipid accumulation in HepG2 cells and in db/db mouse livers. ACLY, ACC, FAS, SCD1, PPARγ, and CD36 were significantly downregulated, while CPT1A, PGC1α, and PPARα were significantly upregulated.

CONCLUSION

CA's therapeutic effect on NAFLD may be attributed to its ability to lower hepatic lipid accumulation, which is mediated by suppression of hepatic lipogenesis and fatty acid intake, as well as increased fatty acid oxidation.