Aloe emodin suppresses myofibroblastic differentiation of rat hepatic stellate cells in primary culture

Enhanced anti-inflammatory and anti-fibrotic effects of nanoparticles loaded with a combination of Aloe vera-Moringa oleifera extracts

Metabolic associated steatohepatitis characterized by lipid accumulation, inflammation and fibrosis, is a growing global health issue, contributing to severe liver-related mortality. With limited effective treatments available, there is an urgent need for novel therapeutic strategies. Moringa oleifera, rich in antioxidants, offers potential for combating steatohepatitis, but its cytotoxicity presents challenges. Aloe vera, renowned for its cytocompatibility and anti-inflammatory effects, shows promise in mitigating these risks. Using infrared spectrometry and mass spectrometry, we identified 1586 metabolites from both plants across 84 chemical classes. By encapsulating these phytochemicals in nanoparticles, we achieved increased solubility, cytocompatibility, and gene modulation to hepatic stellate cells affected by steatohepatitis. Chemoinformatic analysis revealed bioactive metabolites, including hesperetin analogs, known to inhibit TGF-β. Our results demonstrate that these nanoparticles not only improved gene expression modulation related to metabolic associated steatohepatitis, particularly TGF-β and COL1A1, but also outperformed free compounds, highlighting their potential as a novel therapeutic approach.

Hepatoprotective Plants from Bangladesh: A Biophytochemical Review and Future Prospect

Liver diseases are quite prevalant in many densely populated countries, including Bangladesh. The liver and its hepatocytes are targeted by virus and microbes, as well as by chemical environmental toxicants, causing wide-spread disruption of metabolic fuctions of the human body, leading to death from end-stage liver diseases. The aim of this review is to systematically explore and record the potential of Bangladeshi ethnopharmacological plants to treat liver diseases with focus on their sources, constituents, and therapeutic uses, including mechanisms of actions (MoA). A literature survey was carried out using Pubmed, Google Scholar, ScienceDirect, and Scopus databases with articles reported until July, 2020. A total of 88 Bangladeshi hepatoprotective plants (BHPs) belonging to 47 families were listed in this review, including Euphorbiaceae, Cucurbitaceae, and Compositae families contained 20% of plants, while herbs were the most cited (51%) and leaves were the most consumed parts (23%) as surveyed. The effect of BHPs against different hepatotoxins was observed via upregulation of antioxidant systems and inhibition of lipid peroxidation which subsequently reduced the elevated liver biomarkers. Different active constituents, including phenolics, curcuminoids, cucurbitanes, terpenoids, fatty acids, carotenoids, and polysaccharides, have been reported from these plants. The hepatoameliorative effect of these constituents was mainly involved in the reduction of hepatic oxidative stress and inflammation through activation of Nrf2/HO-1 and inhibition of NF-κB signaling pathways. In summary, BHPs represent a valuable resource for hepatoprotective lead therapeutics which may offer new alternatives to treat liver diseases.

Network Pharmacology-Based Study on the Molecular Biological Mechanism of Action for Qingdu Decoction against Chronic Liver Injury

Background

Qingdu Decoction (QDD) is a traditional Chinese medicine formula for treating chronic liver injury (CLI). Materials and methods. A network pharmacology combining experimental validation was used to investigate potential mechanisms of QDD against CLI. We firstly screened the bioactive compounds with pharmacology analysis platform of the Chinese medicine system (TCMSP) and gathered the targets of QDD and CLI. Then, we constructed a compound-target network and a protein-protein interaction (PPI) network and enriched core targets in Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. At last, we used a CLI rat model to confirm the effect and mechanism of QDD against CLI. Enzyme-linked immunosorbent assay (ELISA), western blot (WB), and real-time quantitative polymerase chain reaction (RT-qPCR) were used.

Results

48 bioactive compounds of QDD passed the virtual screening criteria, and 53 overlapping targets were identified as core targets of QDD against CLI. A compound-CLI related target network containing 94 nodes and 263 edges was constructed. KEGG enrichment of core targets contained some pathways related to CLI, such as hepatitis B, tumor necrosis factor (TNF) signaling pathway, apoptosis, hepatitis C, interleukin-17 (IL-17) signaling pathway, and hypoxia-inducible factor (HIF)-1 signaling pathway. Three PPI clusters were identified and enriched in hepatitis B and tumor necrosis factor (TNF) signaling pathway, apoptosis and hepatitis B pathway, and peroxisome pathway, respectively. Animal experiment indicated that QDD decreased serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), endotoxin (ET), and IL-17 and increased prothrombin time activity (PTA) level. WB and RT-qPCR analyses indicated that, compared with the model group, the expression of cysteinyl aspartate specific proteinase-9 (caspase-9) protein, caspase-3 protein, B-cell lymphoma-2 associated X protein (Bax) mRNA, and cytochrome c (Cyt c) mRNA was inhibited and the expression of B-cell lymphoma-2 (Bcl-2) mRNA was enhanced in the QDD group.

Conclusions

QDD has protective effect against CLI, which may be related to the regulation of hepatocyte apoptosis. This study provides novel insights into exploring potential biological basis and mechanisms of clinically effective formula systematically.

Hepatoprotective effect of Xiayuxue decoction ethyl acetate fraction against carbon tetrachloride-induced liver fibrosis in mice via inducing apoptosis and suppressing activation of hepatic stellate cells

CONTEXT

Xiayuxue decoction (XYXD), a traditional Chinese medicine, is used for treating liver disease. However, the potential active constituents and mechanisms are still unclear.

OBJECTIVE

To explore the main active fraction extracts, active ingredients and possible mechanisms of XYXD for anti-hepatic fibrosis.

MATERIALS AND METHODS

Different fractions including ethyl acetate fraction (EF) were prepared from XYXD. These fractions, especially EF, were used to evaluate cell viability, proliferation, cell cycle, cytotoxicity and activation in hepatic stellate cells (HSCs). Liver fibrosis model was established by CCl₄ in C57BL/6 mice, and allocated to CCl₄ group, XYXD group and EF group with normal mice as control. Further, mitochondrial apoptosis-related proteins of HSCs, destruction and angiogenesis of liver sinusoidal endothelial cells (LSECs) and active ingredients of EF were evaluated.

RESULTS

The inhibition of proliferation, increase of S or/and G2/M phase population and suppression of α-SMA and COL-1 expression were obeserved in EF treated-JS1 and -LX2. Liver fibrosis-related indicators were improved by EF similar to XYXD in vivo. EF induced the apoptosis of HSCs in CCl₄-induced fibrosis, and inhibited the expression of HSCs apoptosis pathway-related proteins (JNK and p38-MAPKs), and LSECs destruction and angiogenesis. Multiple ingredients (emodin, rhein, aloe-emodin, prunasin) in EF have shown inhibited the activation of JS1.

DISCUSSION AND CONCLUSION

EF was the main active fraction extracts of XYXD, and the underlying mechanisms might relate to induction of HSCs apoptosis. Emodin, rhein, aloe-emodin and prunasin were main active ingredients of EF, which provides a potential drug for the treatment of liver fibrosis.

Fluorescent spherical mesoporous silica nanoparticles loaded with emodin: Synthesis, cellular uptake and anticancer activity

The natural product emodin (EO) exhibits anti-inflammatory, antiangiogenesis and antineoplastic properties in vitro and in vivo. Due to its biological properties as well as its fluorescence, EO can be useful in pharmacology and pharmacokinetics. To enhance its selectivity to cancer cells, EO was loaded into non-fluorescent and novel fluorescent spherical mesoporous nanoparticles bearing N-methyl isatoic anhydride (SNM~M) or lissamine rhodamine B sulfonyl moieties (SNM~L). The propylamine functionalized mesoporous silica nanomaterial (SNM) were characterized by powder X-ray diffraction (XRD), nitrogen gas sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescence spectroscopy, thermogravimetric analysis (TGA) and UV spectroscopy. The cytotoxicity of EO-loaded nanoparticles was tested against the human colon carcinoma cell line HT-29. Non-loaded SNM did not affect cell proliferation, whereas those loaded with EO were at least as efficient as EO alone. It could be shown by fluorescence microscopy that the uptake of silica nanomaterial by the tumor cells occurred within 2 h and the release of EO occurred within 48 h of treatment. Flow cytometry and Western blot analysis showed that SNM containing EO induced apoptosis in HT-29 cells.

Rhubarb and Astragalus Capsule Attenuates Renal Interstitial Fibrosis in Rats with Unilateral Ureteral Obstruction by Alleviating Apoptosis through Regulating Transforming Growth Factor beta1 (TGF-β1)/p38 Mitogen-Activated Protein Kinases (p38 MAPK) Pathway

BACKGROUND Rhubarb and astragalus capsule (RAC) has been used in the clinical treatment of chronic kidney disease for decades. However, the mechanism of RAC has not been fully elucidated. This study aimed to investigate the protective effect and mechanisms of RAC on unilateral ureteral obstruction (UUO)-induced renal interstitial fibrosis. MATERIAL AND METHODS The main components of RAC are detected by high-performance liquid phase (HPLC). A rat model of UUO was established, and a subset of rats underwent treatment with RAC. Renal function and renal pathology were examined at 14 days and 21 days after the UUO operation. Renal cell apoptosis was detected by TUNEL staining. The levels of Bcl-2 and Bax in the kidney were examined by western blotting, and the levels of collagen I, alpha-SMA, transforming growth factor (TGF)-ß1, and p38 MAPK in the kidneys were detected by immunohistochemistry. RESULTS High-performance liquid phase chromatography showed that RAC contained 1.12 mg/g aloe-emodin, 2.25 mg/g rhein, 1.75 mg/g emodin, and 4.50 mg/g chrysophanol. Administration of RAC significantly decreased the levels of urinary N-acetyl-ß-D-glucosaminidase (NAG), serum blood urea nitrogen (BUN), and creatinine (Scr) and also reduced renal tissue damages and interstitial fibrosis induced by UUO in rats. Moreover, the increased levels of collagen I, alpha-SMA, TGF-ß1, p38 MAPK, and the Bax/Bcl-2 ratio, as well as cell apoptosis in the kidney, were induced by UUO, and were all found deceased by RAC treatment. CONCLUSIONS RAC can improve the renal interstitial fibrosis induced by UUO, and the mechanism may be related to inhibition of renal tubular cell apoptosis via TGF-ß1/p38 MAPK pathway.

Aloe-emodin: A review of its pharmacology, toxicity, and pharmacokinetics

Aloe-emodin is a naturally anthraquinone derivative and an active ingredient of Chinese herbs, such as Cassia occidentalis, Rheum palmatum L., Aloe vera, and Polygonum multiflorum Thunb. Emerging evidence suggests that aloe-emodin exhibits many pharmacological effects, including anticancer, antivirus, anti-inflammatory, antibacterial, antiparasitic, neuroprotective, and hepatoprotective activities. These pharmacological properties lay the foundation for the treatment of various diseases, including influenza virus, inflammation, sepsis, Alzheimer's disease, glaucoma, malaria, liver fibrosis, psoriasis, Type 2 diabetes, growth disorders, and several types of cancers. However, an increasing number of published studies have reported adverse effects of aloe-emodin. The primary toxicity among these reports is hepatotoxicity and nephrotoxicity, which are of wide concern worldwide. Pharmacokinetic studies have demonstrated that aloe-emodin has a poor intestinal absorption, short elimination half-life, and low bioavailability. This review aims to provide a comprehensive summary of the pharmacology, toxicity, and pharmacokinetics of aloe-emodin reported to date with an emphasis on its biological properties and mechanisms of action.

UHPLC-MS/MS method for the quantification of aloin-A in rat plasma and its application to a pharmacokinetic study

Aloin-A (also known as barbaloin), the main bioactive anthraquinone-C-glycoside of Aloe species, exhibits various beneficial pharmacological effects. However, the determination and pharmacokinetic study of aloin-A in rat plasma need to be improved and systematically demonstrated. In the present study, a simple, robust and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for rapid quantification of aloin-A in rat plasma was developed. Plasma preparation was conducted by a single step protein precipitation with obtusin serving as an internal standards (IS) followed by separation of the analytes using an Agilent C18 column with a gradient mobile phase comprised of acetonitrile and formic acid aqueous solution. Negative ion electrospray was used and multiple reaction monitoring transitions were m/z 417.1 → 297.0 for aloin-A and m/z 343.1 → 328.1 for IS, respectively. The developed method was validated with linear range of 1-1000 ng/mL. All validation parameters were well within the acceptance criteria based on the guidance of FDA. The validated approach was successfully applied to analyze samples from a pharmacokinetic study in healthy rats following intravenous and oral administration. Aloin-A was found to be quickly absorbed, extensively distributed and rapidly eliminated. The absolute bioavailability of aloin-A was 5.79%.

Renal protective effects of aloin in a mouse model of sepsis

Aloin is the major anthraquinone glycoside obtained from the Aloe species and exhibits anti-inflammatory and anti-oxidative activities. However, the renal protective effects of aloin and underlying molecular mechanism remain unclear. This study was initiated to determine whether aloin could modulate renal functional damage in a mouse model of sepsis and to elucidate the underlying mechanisms. The potential of aloin treatment to reduce renal damage induced by cecal ligation and puncture (CLP) surgery in mice was measured by assessment of serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, total glutathione, glutathione peroxidase activity, catalase activity, and superoxide dismutase activity. Post-treatment with aloin resulted in a significant reduction in the deleterious renal functions by CLP, such as elevated BUN, creatinine, and urine protein. Moreover, aloin inhibited nuclear factor-κB activation and reduced the induction of nitric oxide synthase and excessive production of nitric acid. Aloin treatment also reduced the plasma levels of interleukin-6 and tumor necrosis factor-α, reduced lethality due to CLP-induced sepsis, increased lipid peroxidation, and markedly enhanced the antioxidant defense system by restoring the levels of superoxide dismutase, glutathione peroxidase, and catalase in kidney tissues. Our study suggested that aloin protects mice against sepsis-triggered renal injury.

Aloin reduces inflammatory gene iNOS via inhibition activity and p-STAT-1 and NF-κB

Aloin is the major anthraquinone glycoside obtained from the Aloe species and exhibits anti-inflammatory and anti-oxidative activities. Here, we aimed to determine the effects of aloin on heme oxygenase-1 (HO-1) induction and on the expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX) 2 in lipopolysaccharide (LPS)-activated human umbilical vein endothelial cells (HUVECs). To the end, aloin was tested whether aloin reduces iNOS protein expression and inflammatory markers (interleukin (IL)-1β and tumor necrosis factor (TNF)-α) in LPS-treated mice lung tissue. The results indicated that aloin affected HO-1 induction and reduced LPS-activated NF-κB-luciferase activity showed to preferential inhibition of iNOS/NO and COX-2/PGE2 that was partly related to inhibition of STAT-1 phosphorylation. In particular, aloin induced translocation of Nrf2 from cytosol into the nucleus by an increased Nrf2-ARE binding activity, and reduced IL-1β production in LPS-activated HUVECs. The reduced expression of iNOS/NO by aloin was reversed by siHO-1RNA-transfection. In LPS-treated mice, aloin significantly reduced iNOS protein in lung tissues, and TNF-α levels in the BALF. We concluded that aloin may be beneficial for treatment of lung injury.

Aloe emodin suppresses EGF‑induced neoplastic cell transformation by inhibiting the ERK/MSK1 and AKT/GSK3β signaling pathways

Natural compounds which can block cell transformation due to potential for chemoprevention have received increased attention. The present study aimed to investigate whether aloe emodin, which is present in aloe latex or the roots of the Rheum palmatum L. are able to block epidermal growth factor (EGF)‑ and tissue plasminogen activator‑induced JB6 C141 cell transformation. The aloe emodin treatment was applied to the JB6 C141 cell neoplastic model. The toxicity of aloe emodin was determined. The present study detected the expression level of AKT serine/threonine kinase 1 (AKT), lysine‑tRNA ligase MSK1 (MSK1) and cyclin D1 using western blotting. The cell proliferation and cell cycle distribution were also monitored. And when 95‑maximal effective dose ranged between 1 and 15 µM, the cell death was evident. Aloe emodin‑treated cells had an impaired anchorage‑independent growth capability, leading to a dose‑dependent reduction of colony formation. Western blotting revealed that aloe emodin had a significant effect on phosphorylation of pyruvate dehydrogenase kinase 1 and glycogen synthase kinase 3β (GSK3β) and AKT was inhibited. The present study determined that the proliferation of JB6 C141 cells was reduced in a dose‑dependent manner and the effect may be associated with its inhibition of the G1/S cell cycle transition. Cyclin D1 transcriptional activity was reduced to 25%, 24 h following aloe emodin treatment. The protein expression of cyclin D1 was inhibited. The findings of the present study indicated that aloe emodin may be able to suppress neoplastic cell transformation by inhibiting the extracellular‑signal regulated kinase/MSK1 and AKT/GSK3β signaling pathways. It may be a potential natural compound for chemoprevention.

Aloe Metabolites Prevent LPS-Induced Sepsis and Inflammatory Response by Inhibiting Mitogen-Activated Protein Kinase Activation

Aloe, a polyphenolic anthranoid-containing Aloe vera leaves, is a Chinese medicine and a popular dietary supplement worldwide. In in vivo situations, polyphenolic anthranoids are extensively broken down into glucuronides and sulfate metabolites by the gut and the liver. The anti-inflammatory potential of aloe metabolites has not been examined. The aim of this study was to investigate the anti-inflammatory effects of aloe metabolites from in vitro (lipopolysaccharides (LPS)-activated RAW264.7 macrophages) and ex vivo (LPS-activated peritoneal macrophages) to in vivo (LPS-induced septic mice). The production of proinflammatory cytokines (TNF-[Formula: see text] and IL-12) and NO was determined by ELISA and Griess reagents, respectively. The expression levels of iNOS and MAPKs were analyzed by Western blot. Our results showed that aloe metabolites inhibited the expression of iNOS, decreased the production of TNF-[Formula: see text], IL-12, and NO, and suppressed the phosphorylation of MAPKs by LPS-activated RAW264.7 macrophages. In addition, aloe metabolites reduced the production of NO, TNF-[Formula: see text] and IL-12 by murine peritoneal macrophages. Furthermore, aloe administration significantly reduced the NO level and exhibited protective effects against sepsis-related death in LPS-induced septic mice. These results suggest that aloe metabolites exerted anti-inflammatory effects in vivo, and that these effects were associated with the inhibition of inflammatory mediators. Therefore, aloe could be considered an effective therapeutic agent for the treatment of sepsis.

Screening of a natural compound library identifies emodin, a natural compound from Rheum palmatum Linn that inhibits DPP4

Historically, Chinese herbal medicines have been widely used in the treatment of hyperglycemia, but the mechanisms underlying their effectiveness remain largely unknown. Here, we screened a compound library primarily comprised of natural compounds extracted from herbs and marine organisms. The results showed that emodin, a natural compound from Rheum palmatum Linn, inhibited DPP4 activity with an in vitro IC₅₀ of 5.76 µM without inhibiting either DPP8 or DPP9. A docking model revealed that emodin binds to DPP4 protein through Glu205 and Glu206, although with low affinity. Moreover, emodin treatment (3, 10 and 30 mg/kg, P.O.) in mice decreased plasma DPP4 activity in a dose-dependent manner. Our study suggests that emodin inhibits DPP4 activity and may represent a novel therapeutic for the treatment of type 2 diabetes.

Isolation and time lapse microscopy of highly pure hepatic stellate cells

Hepatic stellate cells (HSC) are the main effector cells for liver fibrosis. We aimed at optimizing HSC isolation by an additional step of fluorescence-activated cell sorting (FACS) via a UV laser. HSC were isolated from livers of healthy mice and animals subjected to experimental fibrosis. HSC isolation by iohexol- (Nycodenz) based density centrifugation was compared to a method with subsequent FACS-based sorting. We assessed cellular purity, viability, morphology, and functional properties like proliferation, migration, activation marker, and collagen expression. FACS-augmented isolation resulted in a significantly increased purity of stellate cells (>99%) compared to iohexol-based density centrifugation (60–95%), primarily by excluding doublets of HSC and Kupffer cells (KC). Importantly, this method is also applicable to young animals and mice with liver fibrosis. Viability, migratory properties, and HSC transdifferentiation in vitro were preserved upon FACS-based isolation, as assessed using time lapse microscopy. During maturation of HSC in culture, we did not observe HSC cell division using time lapse microscopy. Strikingly, FACS-isolated, differentiated HSC showed very limited molecular and functional responses to LPS stimulation. In conclusion, isolating HSC from mouse liver by additional FACS significantly increases cell purity by removing contaminations from other cell populations especially KC, without affecting HSC viability, migration, or differentiation.

Ethnobotanical survey of usage of fresh medicinal plants in Singapore

ETHNOPHARMACOLOGICAL RELEVANCE

The use of medicinal plants in human health has been documented since ancient times and they provide a useful source of new therapeutics. In Singapore, despite the accessibility to modern healthcare, there still exist pockets of the population who choose to use locally grown fresh medicinal plants for health promotion and even therapeutic purposes. However to date, there is no published report of first-hand account of their usage in Singapore. As land is scarce and rapidly used for re-development, such important knowledge may be lost if not properly documented in time. This work safeguards the local folk knowledge, and provides information on common and scarcely reported fresh medicinal plants. The objective of this study is to gather information regarding the usage of fresh medicinal plants in Singapore through face-to-face interviews.

MATERIALS AND METHODS

Information on demographic data and plant-use methods were collated via face-to-face interviews of 200 fresh medicinal plant users who have used fresh medicinal plants in the last five years. The survey protocol was approved by the National University of Singapore Institutional Review Board and informed consent was obtained from every participant.

RESULTS

A total of 414 plants represented by 104 plant species from 44 families were reportedly used by the 200 participants. The five most commonly used plants were Clinacanthus nutans (34 users), Strobilanthes crispus (31 users), Pereskia bleo (25 users), Aloe vera (18 users) and Zingiber officinale (16 users). Leaves were the most commonly used plant part while preparing a decoction was the most common method of preparation. The majority of interviewees used plants for general health purposes and to treat diseases related to the respiratory system and cancer.

CONCLUSIONS

Our survey has successfully documented the rich wealth of traditional usage and knowledge on 414 fresh medicinal plants grown in Singapore through face-to-face interviews with 200 users. This study will serve as a useful resource for identifying promising plants for future drug discovery efforts. Scientific evaluations of these medicinal plants are warranted and should be carried out.

Emodin suppresses hyperglycemia-induced proliferation and fibronectin expression in mesangial cells via inhibiting cFLIP

As one of the most serious microvascular complications of diabetes and a major cause of end stage renal disease, diabetic nephropathy (DN) is calling for effective treatment strategies. Here, we provide evidence that hyperglycemia can induce proliferation and decreasing apoptosis of mesangial cells (MCs) and subsequent renal dysfunction by up-regulating cellular FLICE-inhibitory protein (cFLIP). Treatment with emodin significantly turns down the accelerated cell cycle and proliferation of MCs cultured in high glucose (HG) via inhibiting cFLIP. In vitro, knockdown of cFLIP can arrest cell cycle and accelerate cell death by activating caspase-8, caspase-3 and caspase-9, and down-regulate proliferating cell nuclear antigen (PCNA). Our results also suggest that emodin regulates cFLIP expression in transcriptional level. Importantly, emodin lessens proteinuria and fibronectin expression in early-stage of streptozotocin (STZ)-induced diabetic rats. These findings demonstrate that emodin represent a promising strategy to prevent renal dysfunction in early-stage of diabetes mellitus.

Enhanced induction of cell cycle arrest and apoptosis via the mitochondrial membrane potential disruption in human U87 malignant glioma cells by aloe emodin

Aloe emodin, one of the active compounds found in Aloe vera leaves, plays an important role in the regulation of cell growth and death. It has been reported to promote the anti-cancer effects in various cancer cells by inducing apoptosis. However, the mechanism of inducing apoptosis by this agent is poorly understood in glioma cells. This research is to investigate the apoptosis and cell cycle arrest inducing by aloe emodin on U87 human malignant glioma cells. Aloe emodin showed a time- and dose-dependent inhibition of U87 cells proliferation and decreased the percentage of viable U87 cells via the induction of apoptosis. Characteristic morphological changes, such as the formation of apoptotic bodies, were observed with confocal microscope by Annexin V-FITC/PI staining, supporting our viability study and flow cytometry analysis results. Our data also demonstrated that aloe emodin arrested the cell cycle in the S phase and promoted the loss of mitochondrial membrane potential in U87 cells that indicated the early event of the mitochondria-induced apoptotic pathway.

Emodin, an 11β-hydroxysteroid dehydrogenase type 1 inhibitor, regulates adipocyte function in vitro and exerts anti-diabetic effect in ob/ob mice

AIM

Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) with the ability to ameliorate metabolic disorders in diet-induced obese mice. In the present study, we investigated the effects of emodin on adipocyte function and the underlying mechanisms in vitro, and its anti-diabetic effects in ob/ob mice.

METHODS

3T3-L1 adipocytes were used for in vitro studies. 11β-HSD1A activity was evaluated with a scintillation proximity assay. The adipogenesis, glucose uptake, lipolysis and adiponectin secretion were investigated in 3T3-L1 adipocytes treated with emodin in the presence of active (corticosterone) or inactive glucocorticoid (11-dehydrocorticosterone). For in vivo studies, ob/ob mice were administered emodin (25 and 50 mg·kg⁻¹·d⁻¹, ip) for 26 d. On the last day of administration, the serum was collected and the mesenteric and perirenal fat were dissected for analyses.

RESULTS

Emodin inhibited the 11β-HSD1 activity in 3T3-L1 adipocytes in concentration- and time-dependent manners (the IC₅₀ values were 7.237 and 4.204 μmol/L, respectively, after 1 and 24 h treatment. In 3T3-L1 adipocytes, emodin (30 μmol/L) suppressed 11-dehydrocorticosterone-induced adipogenesis without affecting corticosterone-induced adipogenesis; emodin (3 μmol/L) reduced 11-dehydrocorticosterone-stimulated lipolysis, but had no effect on corticosterone-induced lipolysis. Moreover, emodin (3 μmol/L) partly reversed the impaired insulin-stimulated glucose uptake and adiponectin secretion induced by 11-dehydrocorticosterone but not those induced by corticosterone. In ob/ob mice, long-term emodin administration decreased 11β-HSD1 activity in mesenteric adipose tissues, lowered non-fasting and fasting blood glucose levels, and improved glucose tolerance.

CONCLUSION

Emodin improves the inactive glucocorticoid-induced adipose tissue dysfunction by selective inhibition on 11β-HSD1 in adipocyte in vitro and improves glycemic control in ob/ob mice.

Emodin, a natural product, selectively inhibits 11beta-hydroxysteroid dehydrogenase type 1 and ameliorates metabolic disorder in diet-induced obese mice

BACKGROUND AND PURPOSE

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is an attractive therapeutic target of type 2 diabetes and metabolic syndrome. Emodin, a natural product and active ingredient of various Chinese herbs, has been demonstrated to possess multiple biological activities. Here, we investigated the effects of emodin on 11beta-HSD1 and its ability to ameliorate metabolic disorders in diet-induced obese (DIO) mice.

EXPERIMENTAL APPROACH

Scintillation proximity assay was performed to evaluate inhibition of emodin against recombinant human and mouse 11beta-HSDs. The ability of emodin to inhibit prednisone- or dexamethasone-induced insulin resistance was investigated in C57BL/6J mice and its effect on metabolic abnormalities was observed in DIO mice.

KEY RESULTS

Emodin is a potent and selective 11beta-HSD1 inhibitor with the IC(50) of 186 and 86 nM for human and mouse 11beta-HSD1, respectively. Single oral administration of emodin inhibited 11beta-HSD1 activity of liver and fat significantly in mice. Emodin reversed prednisone-induced insulin resistance in mice, whereas it did not affect dexamethasone-induced insulin resistance, which confirmed its inhibitory effect on 11beta-HSD1 in vivo. In DIO mice, oral administration of emodin improved insulin sensitivity and lipid metabolism, and lowered blood glucose and hepatic PEPCK, and glucose-6-phosphatase mRNA.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated a new role for emodin as a potent and selective inhibitor of 11beta-HSD1 and its beneficial effects on metabolic disorders in DIO mice. This highlights the potential value of analogues of emodin as a new class of compounds for the treatment of metabolic syndrome or type 2 diabetes.

Emodin, a natural product, selectively inhibits 11beta-hydroxysteroid dehydrogenase type 1 and ameliorates metabolic disorder in diet-induced obese mice

BACKGROUND AND PURPOSE

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is an attractive therapeutic target of type 2 diabetes and metabolic syndrome. Emodin, a natural product and active ingredient of various Chinese herbs, has been demonstrated to possess multiple biological activities. Here, we investigated the effects of emodin on 11beta-HSD1 and its ability to ameliorate metabolic disorders in diet-induced obese (DIO) mice.

EXPERIMENTAL APPROACH

Scintillation proximity assay was performed to evaluate inhibition of emodin against recombinant human and mouse 11beta-HSDs. The ability of emodin to inhibit prednisone- or dexamethasone-induced insulin resistance was investigated in C57BL/6J mice and its effect on metabolic abnormalities was observed in DIO mice.

KEY RESULTS

Emodin is a potent and selective 11beta-HSD1 inhibitor with the IC(50) of 186 and 86 nM for human and mouse 11beta-HSD1, respectively. Single oral administration of emodin inhibited 11beta-HSD1 activity of liver and fat significantly in mice. Emodin reversed prednisone-induced insulin resistance in mice, whereas it did not affect dexamethasone-induced insulin resistance, which confirmed its inhibitory effect on 11beta-HSD1 in vivo. In DIO mice, oral administration of emodin improved insulin sensitivity and lipid metabolism, and lowered blood glucose and hepatic PEPCK, and glucose-6-phosphatase mRNA.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated a new role for emodin as a potent and selective inhibitor of 11beta-HSD1 and its beneficial effects on metabolic disorders in DIO mice. This highlights the potential value of analogues of emodin as a new class of compounds for the treatment of metabolic syndrome or type 2 diabetes.

Emodin suppresses cell proliferation and fibronectin expression via p38MAPK pathway in rat mesangial cells cultured under high glucose

Our previous findings demonstrated that emodin could improve the renal function in rats with diabetic nephropathy, but little is known about its molecular mechanisms. In this study, we investigated the effects of emodin on high glucose (HG)-induced cell proliferation and fibronectin (FN) protein expression in rat mesangial cells, and explored the possible mechanism. Cell proliferation and cell cycle were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assay, respectively. The protein levels of FN, p-p38MAPK, t-p38MAPK, p-CREB, PPARgamma, and CTGF in rat mesangial cells were detected by Western blot. Our results demonstrated that emodin significantly suppressed HG-induced cell proliferation and arrested cell cycle progress. Protein expression of FN, phospho-p38MAPK, phospho-CREB and CTGF was markedly reduced, and PPARgamma protein level was significantly increased after emodin treatment. In conclusion, emodin suppressed HG-induced cell proliferation and FN expression in rat mesangial cells through inhibiting the p38MAPK pathway involved CREB, PPAPgamma and CTGF, suggesting a potential role of emodin in the treatment of diabetic nephropathy.

Final report on the safety assessment of AloeAndongensis Extract, Aloe Andongensis Leaf Juice,aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice,aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract

Plant materials derived from the Aloe plant are used as cosmetic ingredients, including Aloe Andongensis Extract, Aloe Andongensis Leaf Juice, Aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract. These ingredients function primarily as skin-conditioning agents and are included in cosmetics only at low concentrations. The Aloe leaf consists of the pericyclic cells, found just below the plant's skin, and the inner central area of the leaf, i.e., the gel, which is used for cosmetic products. The pericyclic cells produce a bitter, yellow latex containing a number of anthraquinones, phototoxic compounds that are also gastrointestinal irritants responsible for cathartic effects. The gel contains polysaccharides, which can be acetylated, partially acetylated, or not acetylated. An industry established limit for anthraquinones in aloe-derived material for nonmedicinal use is 50 ppm or lower. Aloe-derived ingredients are used in a wide variety of cosmetic product types at concentrations of raw material that are 0.1% or less, although can be as high as 20%. The concentration of Aloe in the raw material also may vary from 100% to a low of 0.0005%. Oral administration of various anthraquinone components results in a rise in their blood concentrations, wide systemic distribution, accumulation in the liver and kidneys, and excretion in urine and feces; polysaccharide components are distributed systemically and metabolized into smaller molecules. aloe-derived material has fungicidal, antimicrobial, and antiviral activities, and has been effective in wound healing and infection treatment in animals. Aloe barbadensis (also known as Aloe vera)-derived ingredients were not toxic in acute oral studies using mice and rats. In parenteral studies, the LD(50) using mice was > 200 mg/kg, rats was > 50 mg/kg, and using dogs was > 50 mg/kg. In intravenous studies the LD(50) using mice was > 80 mg/kg, rats was > 15 mg/kg, and dogs was > 10 mg/kg. The 14-day no observed effect level (NOEL) for the Aloe polysaccharide, acemannan, in the diet of Sprague-Dawley rats, was 50,000 ppm or 4.1 to 4.6 g/kg day(-1). In a 3-month study using mice, Aloe vera (extracted in ethanol) given orally in drinking water at 100 mg/kg produced reproductive toxicity, inflammation, and mortality above that seen in control animals. Aloe vera extracted in methanol and given to mice at 100 mg/kg in drinking water for 3 months caused significant sperm damage compared to controls. Aloe barbadensis extracted with water and given to pregnant Charles Foster albino rats on gestational days (GDs) 0 through 9 was an abortifacient and produced skeletal abnormalities. Both negative and positive results were found in bacterial and mammalian cell genotoxicity assays using Aloe barbadensis-derived material, Aloe Ferox-derived material, and various anthraquinones derived from Aloe. Aloin (an anthraquinone) did not produce tumors when included in the feed of mice for 20 weeks, nor did aloin increase the incidence of colorectal tumors induced with 1,2-dimethylhydrazine. Aloe-emodin (an anthraquinone) given to mice in which tumor cells had been injected inhibited growth of malignant tumors. Other animal data also suggest that components of Aloe inhibit tumor growth and improve survival. Various in vitro assays also demonstrated anticarcinogenic activity of aloe-emodin. Diarrhea was the only adverse effect of note with the use of Aloe-derived ingredients to treat asthma, ischemic heart disease, diabetes, ulcers, skin disease, and cancer. Case reports include acute eczema, contact urticaria, and dermatitis in individuals who applied Aloe-derived ingredients topically. The Cosmetic Ingredient Review Expert Panel concluded that anthraquinone levels in the several Aloe Barbadensis extracts are well understood and can conform to the industry-established level of 50 ppm. Although the phototoxicity anthraquinone components of Aloe plants have been demonstrated, several clinical studies of preparations derived from Aloe barbadensis plants demonstrated no phototoxicity, confirming that the concentrations of anthraquinones in such preparations are too low to induce phototoxicity. The characterization of aloe-derived ingredients from other species is not clear. In the absence of well-characterized derivatives, biological studies of these materials are considered necessary. The studies needed are 28-day dermal toxicity studies on Aloe Andongensis Extract, Aloe Andongensis Leaf Juice, Aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice (ingredients should be tested at current use concentrations). In Aloe-derived ingredients used in cosmetics, regardless of species, anthraquinone levels should not exceed 50 ppm. The Cosmetic Ingredient Review Expert Panel advised the industry that the total polychlorobiphenyl (PCB)/pesticide contamination of any plant-derived cosmetic ingredient should be limited to not more than 40 ppm, with not more than 10 ppm for any specific residue and that limits were appropriate for the following impurities: arsenic (3 mg/kg maximum), heavy metals (20 mg/kg maximum), and lead (5 mg/kg maximum).

Gene expression profiles during the activation of rat hepatic stellate cells evaluated by cDNA microarray

Hepatic stellate cells (HSCs) are activated by producing potentially injurious connective tissue components during hepatic fibrosis, thereby exerting a pivotal action in the development of liver fibrogenesis. The aim of this study was to investigate differences in gene expression patterns during the activation of HSCs using complementary cDNA microarrays. HSCs were isolated from normal rat livers and cultured for 0 (3 h), 3, 5 and 7 d. RNA was extracted from cultured cells at each point. The target RNA was hybridized to gene-specific sequence probes immobilized on chips. The hybridization signal was assessed using a confocal laser scanner. Comparison of hybridization signals and patterns allows the identification of mRNAs that are expressed differentially. Statistical analysis was used to classify and cluster the genes according to their up- or downregulation. As a result, 33 upregulated early-stage and 36 upregulated late-stage gene candidates were identified. This time-based study revealed a number of newly discovered genes involved in fibrogenesis during the activation of HSCs.

Emodin suppresses interleukin-1beta induced mesangial cells proliferation and extracellular matrix production via inhibiting P38 MAPK

Previous findings indicate that emodin has anti-proliferation and anti-fibrosis effects on several cell lines. In this study, we investigated the effects of emodin on IL-1beta induced proliferation of mesangial cells (MCs) and on their production of extracellular matrix (ECM), and explored the possible mechanisms. To test the therapeutic effect of emodin on progressive renal disease, we administered emodin to rats in renal failure models induced by subtotal nephrectomy, the renal function was analyzed. Our results showed emodin significantly suppressed IL-1beta induced MC proliferation and arrested the cell-cycle progress in vitro. Fibronectin and collagen IV production by MC were significantly reduced after emodin treatment. P38 mRNA, protein levels of P-P38, P-MKK3/6 and P-MKK4 were quantified. We observed no alterations of P38 expression and P-MKK4 protein content; however, protein levels of P-P38 and P-MKK3/6 significantly decreased after emodin treatment. In the renal failure models, after administration of emodin for eight weeks, the rat renal lesions were significantly ameliorated, as evidenced by the decreased blood creatinine, urea, and the 24-hour urine protein. In conclusion, emodin suppresses IL-1beta induced MC proliferation and ECM production in vitro. We hypothesize that this is achieved by inactivating MKK3/6 and P38. Emodin ameliorates renal failure in subtotal nephrectomized rats, which suggests a potential role of emodin in the treatment of progressive renal diseases.

Anticancer effects of aloe-emodin on HepG2 cells: Cellular and proteomic studies

Aloe-emodin (AE) is one of the main bioactive anthraquinones of Rheum palmatum, a widely used herbal medicine. Several recent studies suggested that AE possesses potent anticancer properties, although the mechanisms are yet to be fully elucidated. The present study aimed to identify the molecular targets of AE in a human hepatocellular carcinoma cell line, HepG2. We first found that AE was more cytotoxic and effective in inducing apoptosis and cell cycle arrest than its analog emodin (EM). Proteomic study using 2-D DIGE revealed that AE affected multiple proteins associated with oxidative stress, cell cycle arrest, antimetastasis, and hepatitis C virus replication. For example, peroxiredoxins (PRDX) and DJ-1, both of which are redox-sensitive proteins, were among those markedly up-regulated, suggesting the presence of oxidative stress in AE-treated cells. Further biochemical studies demonstrated that AE enhanced the intracellular level of reactive oxygen species and oxidation of PRDX-2, -4, and DJ-1. In addition, AE inhibited DNA synthesis via up-regulation of the CDK4 inhibitor p16 and inhibition of Rb phosphorylation. Furthermore, AE was able to decrease cell migration via up-regulation of the metastasis inhibitor, nm23. Taken together, AE induced anticancer effects in HepG2 cells via multiple pathways by affecting different protein targets.

Bakuchiol-induced caspase-3-dependent apoptosis occurs through c-Jun NH2-terminal kinase-mediated mitochondrial translocation of Bax in rat liver myofibroblasts

Liver fibrosis and cirrhosis may be reversible, possibly through the selective clearance of activated hepatic stellate cells/myofibroblasts by apoptosis. Hepatic stellate cells transdifferentiate into myofibroblast-phenotype cells in culture, a process that recapitulates hepatic stellate cell activation in vivo. Bakuchiol, a prenylated phenolic terpene isolated from the seed of Psoralea corylifolia L. (Leguminosae), reduced activated hepatic stellate cells when treated to rats during liver injury recovery period as demonstrated by alpha-smooth muscle actin immunostaining in rat liver and induced apoptosis in activated hepatic stellate cells/myofibroblasts as demonstrated by DNA fragmentation, activation of caspase-3, release of cytochrome c into the cytoplasm, translocation of Bax into mitochondria, and the proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) in vitro. Bakuchiol-induced apoptosis was prevented by z-DEVD-fmk, a specific inhibitor of caspase-3, and z-VAD-fmk, a general caspase inhibitor, suggesting that bakuchiol-induced apoptosis occurs through a caspase-3-dependent pathway in vitro. Bakuchiol treatment stimulated the activation of extracellular signal-regulated kinase 1/2 (ERK), c-Jun NH2-terminal protein kinase (JNK), and p38 mitogen-activated protein kinases (MAPK) in vitro. Pretreatment with SP600125 attenuated the bakuchiol-induced translocation of Bax into mitochondria, cytochrome c release into the cytosol, caspase-3 activation, and PARP cleavage. In contrast, preincubation with SB203580, a p38 MAPK inhibitor, and U0126, an ERK inhibitor, had no effect on bakuchiol-induced cell death and caspase-3 activity. Taken together, these findings indicate that bakuchiol induces caspase-3-dependent apoptosis through the activation of JNK, followed by Bax translocation into mitochondria in rat liver myofibroblasts.

Aloe emodin-induced apoptosis in t-HSC/Cl-6 cells involves a mitochondria-mediated pathway

The aim of our study was to clarify the apoptosis pathway induced by aloe emodin, an hydroxyanthraquinone present in aloe vera leaves, in rat hepatic stellate cells transformed by simian virus 40 (t-HSC/Cl-6), which retain the features of activated rat stellate cells. Apoptosis was determined by DNA fragmentation, caspase activity assay and western blotting analysis. Treatment of t-HSC/Cl-6 cells with 12.5, 25, or 50 microM aloe emodin inhibited t-HSC/Cl-6 cell viability in a dose- and time-dependent manner. The induction of apoptosis by aloe emodin was confirmed by typical DNA ladder formation and annexin v-propidium iodide flow-cytometric analysis. Aloe emodin treatment of t-HSC/Cl-6 cells caused activation of caspase-3 and caspase-9, detected with a caspase activity assay, although no change was observed in caspase-8 activity. Western blotting showed caspase-3 and caspase-9 active forms and the subsequent proteolytic cleavage of poly(ADP-ribose) polymerase. Aloe emodin induced mitochondrial membrane depolarization. Our data also show that cytochrome c increased in the cytosol but decreased in the mitochondria in a time-dependent manner. Increased Bax and unchanged Bcl-2 levels resulted in an increased Bax/Bcl-2 ratio. Thus, our research provides evidence that aloe emodin-induced apoptosis involves a mitochondria-associated apoptosis pathway.

Influence of serum collected from rat perfused with compound Biejiaruangan drug on hepatic stellate cells

AIM: To observe the effect of compound Biejiaruangan decoction (CBJRGC) (composite prescription of Carapax trionycis for softening the liver) on proliferation, activation, excretion of collagen and cytokine of hepatic stellate cells (HSCs) and to find the mechanism of prevention and treatment of hepatic fibrosis by CBJRGC.

METHODS: Using MTT, immunohistochemistry and image analysis technology, the related indexes for proliferation, activation, excretion of collagen and cytokine of hepatic stellate cells were detected in 24 h, 48 h, and 72 h after adminstration of different dosages of CBJRGC.

RESULTS: Statistical analysis showed that serum collected from rat perfused with CBJRGC could restrain the proliferation of HSC in 48 h and 72 h especially in high and medium dosage groups, markedly decrease the expression of desmin, synapsin and platelet derived growth factor (PDGF) in HSC in 24 h, 48 h and 72 h, as well as the expression of α-SMA, collagen III, TIMP and TGFβ1 in 48 h and 72 h, decrease the excretion of collagen I in 72 h. CBJRGC serum had no significant effect on collagens I, III and TIMP in 24 h.

CONCLUSION: CBJRGC serum has a good curative effect on hepatic fibrosis. Its main mechanism may be related to the following factors. The drug serum can restrain the proliferation and activation of HSC, decrease the number of activated HSC and the total number of HSC, the excretion of collagens I, III, enhance the degradation of collagen and restore the balance of synthesis and degradation of collagen, inhibit the expression of transforming growth factor β1 (TGFβ1) and platelet derived growth factor (PDGF) in HSC, block and delay the process of hepatic fibrosis. Synapsin is a new marker of activation of HSC, which provides a theoretical and testing basis for neural regulation in the developing process of hepatic fibrosis.

Increased expression of O-acetyl disialoganglioside synthase during rat liver fibrogenesis relates to stellate cell activation

The activation of the hepatic stellate cell (HSC) is a key step in liver fibrogenesis. Utilizing large scale sequencing of a 3'-directed cDNA library, we investigated expression profiles of quiescent and activated rat HSCs. During the activation process, O-acetyl disialoganglioside synthase (OAcGD3S) was identified as one of the significant upregulated factors. Upregulation of OAcGD3S in cultured HSCs was confirmed by both Northern and Western blot analyses. OAcGD3S expression in models of experimental liver fibrosis was investigated at the mRNA level using RT-PCR. The expression of OAcGD3S protein in activated rat HSCs and in experimental fibrotic livers was demonstrated by immunohistochemistry. In situ hybridization revealed OAcGD3S mRNA expression in areas of ductular proliferation. Furthermore, O-acetyl GD3 protein was detected in activated rat HSCs and human cirrhosis livers. This study shows that OAcGD3S is strongly expressed during liver fibrogenesis and HSCs seem to be the major cellular sources of OAcGD3S in the liver.

Butein suppresses myofibroblastic differentiation of rat hepatic stellate cells in primary culture

Hepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis. In this study, we investigate the inhibitory effect of butein on the activation and proliferation of rat primary cultured hepatic stellate cells. Possible cytotoxic effects were measured on stellate cells and hepatocytes using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of butein on the production of collagen and smooth muscle alpha-actin proteins were examined at the same concentration, by western blot. The effects of butein on alpha1(I) collagen, tissue inhibitor of metalloproteinase-1, and metalloproteinase-13 gene expression in activated stellate cells were investigated by measuring mRNA levels using reverse transcription polymerase chain reaction. The effect of butein on DNA synthesis was also determined. Butein, at a concentration of 1 microg mL(-1), reduced DNA synthesis without affecting cell viability, and downregulated smooth muscle alpha-actin and type-I collagen expression, and alpha1(I) collagen and tissue inhibitor of metalloproteinase-1 mRNA expression, while treatment with butein induced metalloproteinase-13 mRNA expression. These findings suggest that butein is a potent inhibitor of stellate cell transformation.