Cortex Dictamni extract induces apoptosis of activated hepatic stellate cells via STAT1 and attenuates liver fibrosis in mice

A Methodology for Quantitation of Dictamnine and Fraxinellone and its Application to Study Pharmacokinetics and Bioavailability in Rats Via Oral and Intravenous Administration

The pharmacological activities of dictamnine and fraxinellone have been well reported; however, only a few studies have focused on the pharmacokinetics and bioavailability of concomitant delivery of these drugs in vivo. To shed light on this neglected area, we developed a rapid and sensitive UPLC-MS/MS method that quantified the levels of dictamnine and fraxinellone simultaneously in rat plasma. This method was initiated by a one-step protein precipitation strategy to purify plasma samples collected from rats treated with either oral or intravenous administration of dictamnine and fraxinellone. The mobile phase contained acetonitrile and 0.1% formic acid at a steady flow rate of 0.6 mL/min. As a result, an excellent analyte peak resolution was achieved, and the entire process took only 3 min per sample. The results were indicative of the desired linearity (r2 ≥ 0.999), precision (RSD% was within 15%), accuracy (RE% was within 15%), recoveries (≥80.66 and 68.15% for dictamnine and fraxinellone, respectively) and matrix effects (≥94.66 and 91.37% for dictamnine and fraxinellone, respectively). Additionally, the detectable limits of these two compounds were both low even when they reached 5 ng/mL. Taken together, these findings contribute to a better understanding of the pharmacokinetics and bioavailability properties of concomitant delivery of dictamnine and fraxinellone.

High-Throughput Immunological Analysis of Dictamni Cortex: Implication in the Quality Control of Herbal Medicine

Quality inconsistency of herbal medicine is an obstacle that limits the extensive use and study of traditional Chinese medicine. Differences in environmental conditions and processing methods of herbal medicine often result in varying clinical outcomes in patients. Standard chemical markers used for the quality control (QC) of herbal medicine are usually the most abundant and characteristic components, which may not be therapeutically relevant or cannot comprehensively reflect the biological quality of the herbs. In view of this, a novel QC method for better assessment of herbal medicine has been developed via bioactivities analysis. Immunological activities of Dictamni Cortex, a typical herbal medicine for the treatment of various inflammatory diseases, from different geographical locations in China, were evaluated. Upon in vitro treatment of their water and ethanol extracts, distinct patterns of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, IL-12p70, IL-1β, and chemokine CXCL8 were released from the lipopolysaccharides- and/or phytohaemagglutinin-stimulated human peripheral blood mononuclear cells (PBMC). Thus, in addition to the commonly used morphological, chemical, or DNA markers, the novel high-throughput profiling of inflammatory cytokines and chemokines of PBMC upon treatment with herbal extracts could be an important reference to help for the quality control of herbal medicine in the future.

Cortex Dictamni extracts inhibit over-proliferation and migration of rat airway smooth muscle cells via FAK/p38/Bcl-2 signaling pathway

Airway smooth muscle (ASM) is a prominent effecter in maintaining bronchial muscle contraction and responsible for airway hyper-responsiveness (AHR); the phenotype change and over-proliferation of airway smooth muscle cells (ASMCs) play key roles in the pathogenesis of asthma. The aim of this study was to investigate the anti-proliferation effects of Cortex Dictamni aqueous extract (CDAE) and ethanol extract (CDE) on ASMCs and the possible underline mechanisms. Cell proliferation rates were determined by MTT assay; matrix metalloproteinases-2 (MMP-2) activity was examined by gelatin zymography; cell proliferation and migration were appraised by in-vitro cell-gap closure assessment; protein expressions of p38, Bcl-2 and FAK of ASMCs were evaluated by western blotting and Ca²⁺ influx of cells was measured by confocal laser microscope. Our data demonstrated that the proliferation, migration and MMP-2 expressions of ASMCs were inhibited by CDAE or CDE; the protein expressions of p38, Bcl-2 and FAK in ASMCs were substantially reduced by CDAE and CDE detected by western blotting or immunocytochemistry; also the increased calcium influx has been observed instantaneously after ASMCs were stimulated by CDAE or CDE. These findings suggested that Cortex Dictamni extracts might have inhibitory effects on ASMCs over-proliferation which could be one of the underline mechanisms for the therapy of asthma.

Protective effects of ellagic acid against tetrachloride-induced cirrhosis in mice through the inhibition of reactive oxygen species formation and angiogenesis

Ellagic acid has been proven to have anticancer, antimutation, antimicrobial and antiviral functions. The present study investigated whether treatment with ellagic acid was able to prevent tetrachloride (CCl4)-induced cirrhosis through the inhibition of reactive oxygen species (ROS) formation and angiogenesis. CCl₄ diluted in olive oil at a final concentration of 10% was used to induce a cirrhosis model. A total of 40 mice were random allocated into four groups, as follows: Control, cirrhosis model, 7.5 mg/kg ellagic acid and 15 mg/kg ellagic acid groups. In the control group, mice were given normal saline. The results indicated that ellagic acid exerted a protective effect, evidently preventing CCl₄-induced cirrhosis. In addition, treatment with ellagic acid significantly inhibited collagen I and inducible nitric oxide synthase protein expression levels in CCl₄-induced cirrhosis mice. Oxidative stress and ROS formation were also significantly reduced by ellagic acid treatment. The protein expression levels of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2), and the caspase-3 activity were significantly inhibited by treatment with ellagic acid. In conclusions, these results suggest that ellagic acid exerted protective effects against CCl₄-induced cirrhosis through the inhibition of ROS formation and angiogenesis.

Rapid identification and global characterization of multiple constituents from the essential oil of Cortex Dictamni based on GC-MS

The root of Dictamnus dasycarpus Turcz., also known as Cortex Dictamni, is a Chinese herbal medicine that has been commonly used in the treatment of inflammation, microbial infection, cancer, and other diseases in China for thousands of years. Recently, the essential oil of Cortex Dictamni has been widely studied, and a large number of volatile constituents have been discovered. However, the research of the essential oil of Cortex Dictamni in vivo remains unknown, especially the constituents absorbed into blood after oral administration. Hence, a sensitive and rapid method using gas chromatography with mass spectrometry combined with MassHunter software and the National Institute of Standards and Technology 2014 database was used to investigate the absorbed components in rat serum after oral administration of the essential oil of Cortex Dictamni. With the established method, a total of 36 compounds were screened and identified in the essential oil of Cortex Dictamni based on the mass spectrometry data and compound database. Among them, eight compounds, elemol, thymol methyl ether, β-eudesmol, β-cyclocostunolid, guaiazulene, trans-4-hydroxystilbene, ethyl oleate, and monoelaidin, were tentatively characterized in rat serum. This work demonstrated that the established method proved to be a powerful technique for rapid, simple, reliable, and automated identification of bioactive components of herbal medicine.

In vitro and in vivo antioxidative and hepatoprotective activity of aqueous extract of Cortex Dictamni

AIM

To investigate the antioxidant and hepatoprotective effects of Cortex Dictamni aqueous extract (CDAE) in carbon tetrachloride (CCl₄)-induced liver damage in rats.

METHODS

The in vitro antioxidant effect of CDAE was investigated using α,α-diphenyl-β-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), β-carotene bleaching, reducing power, and thiobarbituric acid reactive substance assays. A linoleic acid system, including ferric thiocyanate (FTC) and thiobarbituric acid (TBA) assays, was used to evaluate the inhibition of lipid peroxidation. The in vivo hepatoprotective and antioxidant effects of CDAE against CCl₄-induced liver damage were evaluated in Sprague-Dawley rats. Silymarin was used as a positive control. Liver damage was assessed by determining hepatic histopathology and liver marker enzymes in serum. Enzyme and non-enzyme antioxidant levels and lipid peroxide content were measured in the liver. Cytochrome P450 2E1 (CYP2E1) protein expression was measured via immunohistochemical staining. Nuclear factor E2-related factor (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H quinine oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase catalytic subunit (γ-GCSc) protein expression was measured by Western blot.

RESULTS

Our results showed that CDAE exhibited a strong antioxidant activity in vitro. CDAE scavenged DPPH and ABTS radicals in a dose-dependent manner. CDAE inhibited lipid peroxidation with a lipid peroxide inhibition rate of 40.6% ± 5.2%. In the FTC and TBA assays, CDAE significantly inhibited lipid peroxidation (P < 0.01). In vivo histopathological studies indicated that CCl₄-induced liver injury was alleviated following CDAE treatment in rats of both sexes. CDAE (160 and 320 mg/kg) significantly prevented CCl₄-induced elevations of alkaline phosphatase, glutamate pyruvate transaminase, aspartate aminotransferase, and total bilirubin levels in rats of both sexes (P < 0.05, 0.01, or 0.001). Moreover, CDAE restored the decreased activities of hepatic antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase, as well as non-enzyme antioxidant glutathione, which were induced by CCl₄ treatment. CDAE significantly suppressed the up-regulation of CYP2E1 and promoted Nrf2, HO-1, NQO1, and γ-GCSc protein expression.

CONCLUSION

CDAE exhibits good antioxidant performance in vitro, with marked radical-scavenging and anti-lipid peroxidation activities. CDAE is effective in preventing CCl₄-induced hepatic damage in rats of both sexes. The hepatoprotective activity of CDAE may be attributable to its antioxidant activity, which may involve Keap1-Nrf2-mediated antioxidant regulation.

Preclinical Models for Investigation of Herbal Medicines in Liver Diseases: Update and Perspective

Liver disease results from a dynamic pathological process associated with cellular and genetic alterations, which may progress stepwise to liver dysfunction. Commonly, liver disease begins with hepatocyte injury, followed by persistent episodes of cellular regeneration, inflammation, and hepatocyte death that may ultimately lead to nonreversible liver failure. For centuries, herbal remedies have been used for a variety of liver diseases and recent studies have identified the active compounds that may interact with liver disease-associated targets. Further study on the herbal remedies may lead to the formulation of next generation medicines with hepatoprotective, antifibrotic, and anticancer properties. Still, the pharmacological actions of vast majority of herbal remedies remain unknown; thus, extensive preclinical studies are important. In this review, we summarize progress made over the last five years of the most commonly used preclinical models of liver diseases that are used to screen for curative herbal medicines for nonalcoholic fatty liver disease, liver fibrosis/cirrhosis, and liver. We also summarize the proposed mechanisms associated with the observed liver-protective, antifibrotic, and anticancer actions of several promising herbal medicines and discuss the challenges faced in this research field.

Acute and sub-chronic oral toxicity profiles of the aqueous extract of Cortex Dictamni in mice and rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cortex Dictamni is used in Chinese folk medicine for the treatment of jaundice, cough, rheumatism and some skin diseases; however, its possible toxicity has not been rigorously studied. The present investigation was carried out to evaluate the safety of Cortex Dictamni aqueous extract (CDAE) by acute and sub-chronic toxicity studies.

MATERIALS AND METHODS

In acute toxicity tests, seven groups of mice (n=5/group/sex) were orally treated with doses of 0, 28.7, 33.6, 39.7, 46.7, 54.9 and 64.6g/kg of CDAE and general behavior, adverse effects and mortality were recorded for up to 14 days. In sub-chronic toxicity assays, animals received CDAE by gavage at the doses of 0, 3.0, 6.0 or 12.0g/kg/day (n=10/group/sex) for 4 weeks and then followed for a 2-week recovery period. The biochemical, hematological and morphological parameters were determined.

RESULTS

In adult mice, single oral administrations of CDAE (0-64.6g/kg body weight) induced an increase in the incidence of general behavioral adverse effects. The mortality rate also increased with increasing dosage (LD50=48.2g/kg). In rats, daily single oral doses of CDAE were well tolerated behaviorally after 4 weeks and induced no significant changes in body weights. However, the absolute and relative liver weight at the end of both administration and recovery periods were significantly elevated, although the histological examination of various organs revealed no differences between the control and the treated groups. The hematological and biochemical parameters were significantly changed; lymphocytes, alanine transaminase, alkaline phosphatase levels showed a significant decrease while neutrophilic granulocyte, albumin, total cholesterol, glucose and blood urea nitrogen levels showed a significant increase, suggesting disturbances of hematopoiesis and liver and kidney functions.

CONCLUSIONS

Overall, the acute toxicity of CDAE was not clearly observed. However, it is possible that CDAE has a selective toxicity considering the changes in some hematological and liver function parameters and the liver-body weight ratios in the sub-chronic oral toxicity study.

Tupistra chinensis extract attenuates murine fulminant hepatitis with multiple targets against activated T lymphocytes

OBJECTIVES

The extract of Tupistra chinensis (TCE) is traditionally used for the treatment of inflammatory diseases in southwestern China for hundreds of years. The present study was designed to investigate the effects of the TCE against experimental hepatitis and to illustrate its potential mechanisms.

METHODS

Effects of TCE were investigated on Con A-induced hepatitis. Profiles of multiple cytokines were measured with biometric immuno-sandwich ELISA. Proliferation, activation and apoptosis of T lymphocytes were evaluated using Western blot, MTT analysis and flow cytometry.

KEY FINDINGS

TCE significantly inhibited levels of serum transaminases and lactic dehydrogenase in mice with Con A-induced hepatitis, accompanied with marked alleviation of the liver microscopic appearances. Moreover, it decreased levels of inflammatory cytokines in a concentration-dependent manner both in vivo and in vitro. It also suppressed mitogen-activated protein kinases and NF-κB-signalling in liver. These effects of TCE are attributed to its inhibition on activated T cells but not to hepatocytes protection. Flow cytometry and immunoblot assay data showed its effects on STAT1/NF-κB-signalling blockage and apoptosis induction in activated T cells.

CONCLUSION

Our findings illustrate the significant potential of TCE as a novel approach for treatment of T cell-mediated inflammatory diseases.

Enhanced apoptosis in post-liver transplant hepatitis C: Effects of virus and immunosuppressants

Hepatitis C (HCV)-infected patients have a poorer survival post-liver transplantation compared to patients transplanted for other indications, since HCV recurrence post-transplant is universal and commonly follows an aggressive course. There is increasing evidence that in the non-transplant setting, induction of hepatocyte apoptosis is one of the main mechanisms by which HCV drives liver inflammation and fibrosis, and that HCV proteins directly promote apoptosis. Recent studies have shown that post-liver transplant, there is a link between high levels of HCV replication, enhanced hepatocyte apoptosis and the subsequent development of rapidly progressive liver fibrosis. Although the responsible mechanisms remain unclear, it is likely that immunosuppressive drugs play an important role. It is well known that immunosuppressants impair immune control of HCV, thereby allowing increased viral replication. However there is also evidence that immunosuppressants may directly induce apoptosis and this may be facilitated by the presence of high levels of HCV replication. Thus HCV and immunosuppressants may synergistically interact to further enhance apoptosis and drive more rapid fibrosis. These findings suggest that modulation of apoptosis within the liver either by changing immunosuppressive therapy or the use of apoptosis inhibitors may help prevent fibrosis progression in patients with post-transplant HCV disease.