Immunosuppressive effects of the traditional Chinese herb Qu Mai on human alloreactive T cells

Taraxasterol prompted the anti-tumor effect in mice burden hepatocellular carcinoma by regulating T lymphocytes

Hepatocellular carcinoma (HCC) is a common digestive malignant tumor with high morbidity and mortality worldwide, however, the treatment of HCC and prognosis of patients are not optimistic, finding more effective treatments are imperative. Taraxacum officinale (L.) Weber ex F.H.Wigg is a perennial herb of compositae, and our study has demonstrated that Taraxacum officinale polysaccharide has certain anti-tumor effect on HCC cells. Taraxasterol (TS) is a natural product extracted from Taraxacum officinale with strong physiological, pharmacological and biological activities, but the effect of TS on HCC is yet to be determined. Therefore, the aim of this study is to explore the effect of dandelion sterol on HCC in vivo and in vitro. The results showed that TS significantly inhibited the proliferation, induced apoptosis and blocked cell cycle in HCC cell lines HepG2 and Huh7 cells in vitro. TS inhibited the tumor growth of H22 bearing mice and the expression of Ki67 in vivo. More importantly, TS regulated the immunity of H22 bearing mice by elevating the ratio of CD4⁺ T cells in spleen, and increasing the number of T cell infiltration in tumor tissue. Except immunomodulation, the mechanism of tumor growth inhibition may be related to the regulation of apoptosis related proteins and IL-6/STAT3 pathway. TS significantly inhibited the growth of HCC cells both in vitro and in vivo. The study would provide a theoretical basis for the new application of TS and the adjuvant treatment of malignant tumor with traditional Chinese medicine.

The Emerging Role of Central and Peripheral Immune Systems in Neurodegenerative Diseases

For decades, it has been widely believed that the blood-brain barrier (BBB) provides an immune privileged environment in the central nervous system (CNS) by blocking peripheral immune cells and humoral immune factors. This view has been revised in recent years, with increasing evidence revealing that the peripheral immune system plays a critical role in regulating CNS homeostasis and disease. Neurodegenerative diseases are characterized by progressive dysfunction and the loss of neurons in the CNS. An increasing number of studies have focused on the role of the connection between the peripheral immune system and the CNS in neurodegenerative diseases. On the one hand, peripherally released cytokines can cross the BBB, cause direct neurotoxicity and contribute to the activation of microglia and astrocytes. On the other hand, peripheral immune cells can also infiltrate the brain and participate in the progression of neuroinflammatory and neurodegenerative diseases. Neurodegenerative diseases have a high morbidity and disability rate, yet there are no effective therapies to stop or reverse their progression. In recent years, neuroinflammation has received much attention as a therapeutic target for many neurodegenerative diseases. In this review, we highlight the emerging role of the peripheral and central immune systems in neurodegenerative diseases, as well as their interactions. A better understanding of the emerging role of the immune systems may improve therapeutic strategies for neurodegenerative diseases.

Dianthi herba: a comprehensive review of its botany, traditional use, phytochemistry, and pharmacology

Dianthi herba (called “Qumai” in Chinese) is the dried aerial part of Dianthus superbus L. and Dianthus chinensis L. The species are mainly distributed in the temperate and warm temperate regions in the northern hemisphere, and some regions in Africa and Oceania, as well as South America. However, the distribution pattern of Dianthi herba has not been reviewed. In this review, we summarize the research progress on the botany, traditional use, phytochemistry, pharmacology, toxicology, and clinical applications of Dianthi herba. Approximately 194 chemical compounds have been identified and isolated from Dianthi herba, the most important being triterpenoid saponins, flavonoids, and volatile oil compounds. These compounds possess antiviral, anticancer, antioxidant, and antimicrobial properties, inter alia. Further studies should be carried out on Dianthi herba to elucidate more of its active principles and their mechanisms of action.

Medicinal herbs Fructus corni and Semen cuscutae suppress allograft rejection via distinct immune mechanisms

Achieving long-term allograft survival without continuous global immunosuppression is highly desirable because constant immunosuppression causes severe side effects. Traditional Chinese medicine (TCM) has been utilized to treat numerous diseases for centuries. To seek novel immunosuppressive agents, we investigated several Chinese herbal formulas that have been shown to be effective in treating autoimmune diseases. C57BL/6 mice were transplanted with a skin graft from Balb/C donors and treated orally with the TCM. IL-12-expressing dendritic cells and CD4+FoxP3+ Tregs were quantified by flow cytometer while intragraft IL-12 gene expression was measured by real-time PCR. Here we identified a unique TCM, San Si formula, which contains three herbs: Fructus corni (FC), Fructus ligustri lucidi (FLL) and Semen cuscutae (SC). We found that either SC or FC, but not FLL, significantly prolonged skin allograft survival while SC plus FC or San Si formula further delayed allograft rejection compared to SC or FC alone. SC and FC, which did not contain cyclosporine and rapamycin, reduced graft-infiltrating T cells and suppressed their proliferation. Importantly, it was SC, but not FC, that induced CD4+FoxP3+ Tregs in recipients. Tregs induced by SC were also more potent in suppression. In contrast, FC repressed both intracellular IL-12 expression by intragraft DCs and IFNγ expression by graft-infiltrating T cells. Moreover, FC inhibited intragraft IL-12 gene expression. Depleting Tregs and providing exogenous IL-12 completely reversed allograft survival induced by SC plus FC. Thus, SC and FC synergistically suppress allograft rejection via distinct mechanisms.

Memory CD4+ T cells are suppressed by CD8+ regulatory T cells in vitro and in vivo

BACKGROUND

Acute graft rejection mediated by alloreactive memory CD4⁺ T cells is a major obstacle to transplantation tolerance. It has been reported that CD8⁺ T regulatory cells (Tregs) have the ability to induce graft tolerance by restraining the function of activated CD4⁺ T cells, but not including memory T cells. The aim of this study is to elucidate the effect of CD8⁺ Tregs on alloreactive memory CD4⁺ T cells.

METHODS

We detected Qa-1 expression and performed proliferative assay on memory CD4⁺ T cells. All memory CD4⁺ T cells were purified from mice receiving skin allografts. We performed inhibitory and cytotoxic assays on CD8⁺ Tregs, which were isolated from a T cell vaccination mouse model, and IL-2, IL-4, IL-10 and IFN-γ levels were measured in co-culture supernatants by ELISA. To confirm CD8⁺ Tregs inhibition of memory CD4⁺ T cells in-vivo, we utilized a murine model of cardiac allograft transplantation.

RESULTS

Memory CD4⁺ T cells mediated acute allograft rejection, and CD8⁺ Tregs suppressed the proliferation of memory CD4⁺ T cells. In vitro, memory CD4⁺ T cells were inhibited and lysed by CD8⁺ Tregs. There was a positive correlation between IFN-γ levels, and cell lysis rate induced by CD8⁺ Tregs. In-vivo studies demonstrated CD8⁺ Tregs prolonged graft survival times, by inhibiting CD4⁺ memory T cells, through a Qa-1-peptide-TCR pathway.

CONCLUSIONS

CD8⁺ Tregs inhibit CD4⁺ memory T cell-mediated acute murine cardiac allograft rejection, and further prolong graft survival times. These results provide new insights into immune regulation of organ rejection.

Simultaneous Determination of Eight Bioactive Compounds in Dianthus superbus by High-performance Liquid Chromatography

Background:

Dianthus superbus, one of traditional herbal medicine, is widely used to treat urethritis, carbuncles and carcinoma.

Objective:

A simultaneous determination method was established for controlling the quality of D. superbus using the eight compounds, (E)-methyl-4-hydroxy-4-(8a-methyl-3-oxodecahydronaphthalen-4a-yl) (1), diosmetin-7-O(2'',6''-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), vanillic acid (3), 4-hydroxyphenyl acetic acid (4), 4-methoxyphenyl acetic acid (5), (E)-4-methoxycinnamic acid (6), 3-methoxy-4-hydroxyphenylethanol (7), and methyl hydroferulate (8) isolated from D. superbus.

Materials and Methods:

This analysis method was developed using high performance liquid chromatography coupled with diode array detector with a Shishedo C₁₈ column at a column temperature of 3°C. The mobile phase was composed of 0.1% trifluoroacetic acid in water and acetonitrile. The flow rate was 1 ml/min and detection wavelength was set at 205 nm and 280 nm. Validation was performed in order to demonstrate selectivity, accuracy and precision of the method.

Results:

The calibration curves showed good linearity (R² > 0.99). The limits of detection and limits of quantification were within the ranges 0.0159–0.6205 μg/ml and 0.3210–1.8802 μg/ml, respectively. Moreover, the relative standard deviations of intra- and inter-day precision were both <2.98%. The overall recoveries were in the range of 96.23–109.87%. Quantitative analysis of eight compounds in 12 D. superbus samples (D-1–D-12) from various regions were analyzed and compared by developed method.

Conclusion:

As a result, this established method was accurate and sensitive for the quality evaluation of eight compounds isolated from D. superbus and may provide a new basis for quality control of D. superbus.

SUMMARY

A simultaneous determination method of eight compounds in Dianthus superbus was established by high performance liquid chromatography-diode array detector

Developed analysis method is validated with linearity, precious and accuracy

The newly established method was successfully evaluated contents of eight compounds in 12 D. superbus samples (D.1.D.12) from various regions and compared.

Abbreviations used: HPLC: High performance liquid chromatography, LOD: Limits of detection, LOQ: Limits of quantification, RSD: Relative standard deviation.

Cognitive-Enhancing Effect of Dianthus superbus var. Longicalycinus on Scopolamine-Induced Memory Impairment in Mice

Dianthus superbus (D. superbus) is a traditional crude drug used for the treatment of urethritis, carbuncles and carcinomas. The objective of this study was to confirm the cognitive enhancing effect of D. superbus in memory impairment induced mice and to elucidate the possible potential mechanism. Effect of D. superbus on scopolamine induced memory impairment on mice was evaluated using the Morris water maze and passive avoidance tests. We also investigated acetylcholinesterase (AChE) activity and brain-derived neurotropic factor (BDNF) expression in scopolamine-induced mice. HPLC-DAD analysis was performed to identify active compounds in D. superbus. The results revealed that D. superbus attenuated the learning and memory impairment induced by scopolamine. D. superbus also inhibited AChE levels in the hippocampi of the scopolamine-injected mice. Moreover, D. superbus increased BDNF expression in the hippocampus. Eight compounds were identified using HPLC-DAD analysis. The content of 4-hydroxyphenyl acetic acid was higher than contents of other compounds. These results indicated that D. superbus improved memory functioning accompanied by inhibition of AChE and upregulation of BDNF, suggesting that D. superbus may be a useful therapeutic agent for the prevention or treatment of Alzheimer’s disease.

Recent highlights of experimental research for inhibiting tumor growth by using Chinese medicine

To give an overview of contemporary experimental research using Chinese medicine (CM) for the treatment of cancer. As an integral part of mainstream medicine in the People's Republic of China, CM emphasizes improvements in holistic physical condition instead of merely killing tumor cells, which is consistent with the current medical model that advocates patient-oriented treatment. Great progress has been made in experimental research, and the principle aspects include anti-tumor angiogenesis, inducing apoptosis and differentiation, reversing multidrug resistance, and improving immune function. As a current hot topic in cancer research, tumor microenvironment (TME) highlights the mutual and interdependent interaction between tumor cells and their surrounding tissues, and the CM treatment concept bears a striking resemblance to it. To date, primary points of TME include extracellular matrix remodeling, inflammation, hypoxia, and angiogenesis, but trials using CM with a focus on TME are rare. Despite considerable recent development, experimental research on CM for solving cancer issues appears insufficient. Greater efforts in this field are urgently needed.

Immunological aspects of drug-induced liver injury

Drug induced liver injury (DILI) is a common condition of increasing incidence. Many environmental and genetic factors are involved in its pathogenesis, and immunological mechanisms are also thought to contribute to the development and severity of DILI. This review summarizes current understanding of the immunological pathogenesis of DILI and discusses the perspective for clinical applications.