Carthamus tinctorius Enhances the Antitumor Activity of Dendritic Cell Vaccines via Polarization toward Th1 Cytokines and Increase of Cytotoxic T Lymphocytes

Anticancer, Immunomodulatory, and Phytochemical Screening of Carthamus oxyacantha M.Bieb Growing in the North of Iraq

Carthamus oxyacantha M.Bieb is a promising repository of active phytochemicals. These bioactive compounds work synergistically to promote the plant's antioxidant, anticancer, and immunomodulatory capabilities. The present study aimed to discover the potential immunomodulatory and cytotoxicity of different extracts of Carthamus oxycantha roots. Aqueous ethanol (70%), aqueous methanol (90%), ethyl acetate, and n-hexane extracts were tested against five cell lines (T47D, MDA-MB231, Caco-2, EMT6/P, and Vero). Among these extracts, ethyl acetate and n-hexane extracts showed significant activity in inhibiting the proliferation of cancerous cells because of the presence of several phytochemical compounds, including flavonoids, phenolics, and alkaloids. The n-hexane extract was the most potent extract against T47D and Caco-2 cell lines and had IC50 values of 0.067 mg/mL and 0.067 mg/mL, respectively. In comparison, ethyl acetate extract was active against T47D and MDAMB231, and IC50 values were 0.0179 mg/mL and 0.03 mg/mL, respectively. Both n-hexane and ethyl acetate extracts reduced tumor size (by 49.981% and 51.028%, respectively). Remarkably, Carthamus oxyacantha extracts decreased the average weight of the tumor cells in the in vivo model. The plant induced significant apoptotic activity by the activation of caspase-3, immunomodulation of macrophages, and triggering of pinocytosis. The implications of these intriguing findings demand additional research to broaden the scope of the understanding of this field, opening the doors to the possibilities of using Carthamus oxyacantha M.Bieb as an effective cancer treatment adjuvant in the future.

The potential of plant extracts in cell therapy

Cell therapy is the frontier technology of biotechnology innovation and the most promising method for the treatment of refractory diseases such as tumours. However, cell therapy has disadvantages, such as toxicity and poor therapeutic effects. Plant extracts are natural, widely available, and contain active small molecule ingredients that are widely used in the treatment of various diseases. By studying the effect of plant extracts on cell therapy, active plant extracts that have positive significance in cell therapy can be discovered, and certain contributions to solving the current problems of attenuation and adjuvant therapy in cell therapy can be made. Therefore, this article reviews the currently reported effects of plant extracts in stem cell therapy and immune cell therapy, especially the effects of plant extracts on the proliferation and differentiation of mesenchymal stem cells and nerve stem cells and the potential role of plant extracts in chimeric antigen receptor T-cell immunotherapy (CAR-T) and T-cell receptor modified T-cell immunotherapy (TCR-T), in the hope of encouraging further research and clinical application of plant extracts in cell therapy.

Emerging role of natural products in cancer immunotherapy

Cancer immunotherapy has become a new generation of anti-tumor treatment, but its indications still focus on several types of tumors that are sensitive to the immune system. Therefore, effective strategies that can expand its indications and enhance its efficiency become the key element for the further development of cancer immunotherapy. Natural products are reported to have this effect on cancer immunotherapy, including cancer vaccines, immune-check points inhibitors, and adoptive immune-cells therapy. And the mechanism of that is mainly attributed to the remodeling of the tumor-immunosuppressive microenvironment, which is the key factor that assists tumor to avoid the recognition and attack from immune system and cancer immunotherapy. Therefore, this review summarizes and concludes the natural products that reportedly improve cancer immunotherapy and investigates the mechanism. And we found that saponins, polysaccharides, and flavonoids are mainly three categories of natural products, which reflected significant effects combined with cancer immunotherapy through reversing the tumor-immunosuppressive microenvironment. Besides, this review also collected the studies about nano-technology used to improve the disadvantages of natural products. All of these studies showed the great potential of natural products in cancer immunotherapy.

Impact of TCM on Tumor-Infiltrating Myeloid Precursors in the Tumor Microenvironment

The tumor microenvironment (TME) is composed of tumor cells, blood/lymphatic vessels, the tumor stroma, and tumor-infiltrating myeloid precursors (TIMPs) as a sophisticated pathological system to provide the survival environment for tumor cells and facilitate tumor metastasis. In TME, TIMPs, mainly including tumor-associated macrophage (TAM), tumor-associated dendritic cells (DCs), and myeloid-derived suppressor cells (MDSCs), play important roles in repressing the antitumor activity of T cell or other immune cells. Therefore, targeting those cells would be one novel efficient method to retard cancer progression. Numerous studies have shown that traditional Chinese medicine (TCM) has made extensive research in tumor immunotherapy. In the review, we demonstrate that Chinese herbal medicine (CHM) and its components induce tumor cell apoptosis, directly inhibiting tumor growth and invasion. Further, we discuss that TCM regulates TME to promote effective antitumor immune response, downregulates the numbers and function of TAMs/MDSCs, and enhances the antigen presentation ability of mature DCs. We also review the therapeutic effects of TCM herbs and their ingredients on TIMPs in TME and systemically analyze the regulatory mechanisms of TCM on those cells to have a deeper understanding of TCM in tumor immunotherapy. Those investigations on TCM may provide novel ideas for cancer treatment.

Beneficial Actions of Orostachys japonica and Its Compounds against Tumors via MAPK Signaling Pathways

Tumors are one of the most life-threatening diseases, and a variety of cancer treatment options have been continuously introduced in order to overcome cancer and improve conventional therapy. Orostachys japonica (O. japonica), which is a perennial plant belonging to the genus Orostachys of the Crassulaceae family, has been revealed to exhibit pharmacological properties against various tumors in numerous studies. The present review aimed to discuss the biological actions and underlying molecular mechanisms of O. japonica and its representative compounds-kaempferol and quercetin-against tumors. O. japonica reportedly has antiproliferative, anti-angiogenic, and antimetastatic activities against various types of malignant tumors through the induction of apoptosis and cell cycle arrest, a blockade of downstream vascular endothelial growth factor (VEGF)-VEGFR2 pathways, and the regulation of epithelial-to-mesenchymal transition. In addition, emerging studies have highlighted the antitumor efficacy of kaempferol and quercetin. Interestingly, it was found that alterations of the mitogen-activated protein kinase (MAPK) signaling cascades are involved in the pivotal mechanisms of the antitumor effects of O. japonica and its two compounds against cancer cell overgrowth, angiogenesis, and metastasis. In summary, O. japonica could be considered a preventive and therapeutic medicinal plant which exhibits antitumor actions by reversing altered patterns of MAPK cascades, and kaempferol and quercetin might be potential components that can contribute to the efficacy and underlying mechanism of O. japonica.

Chinese Herbal Medicine and Its Regulatory Effects on Tumor Related T Cells

Traditional Chinese medicine is an accepted and integral part of clinical cancer management alongside Western medicine in China. However, historically TCM physicians were unaware of the chemical constituents of their formulations, and the specific biological targets in the body. Through HPLC, flow cytometry, and other processes, researchers now have a much clearer picture of how herbal medicine works in conjunction with the immune system in cancer therapy. Among them, the regulation of tumor-related T cells plays the most important role in modulating tumor immunity by traditional Chinese medicine. Encouraging results have been well-documented, including an increase in T cell production along with their associated cytokines, enhanced regulation of Tregs and important T cell ratios, the formation and function of Tregs in tumor microenvironments, and the promotion of the number and function of normal T Cells to reduce conventional cancer therapy side effects. Chinese herbal medicine represents a rich field of research from which to draw further inspiration for future studies. While promising agents have already been identified, the vast majority of Chinese herbal mechanisms remain undiscovered. In this review, we summarize the effects and mechanisms of specific Chinese herbs and herbal decoctions on tumor related T cells.

A Potential Herbal Adjuvant Combined With a Peptide-Based Vaccine Acts Against HPV-Related Tumors Through Enhancing Effector and Memory T-Cell Immune Responses

Viral infection is associated with many types of tumorigenesis, including human papillomavirus (HPV)-induced cervical cancer. The induction of a specific T-cell response against virus-infected cells is desired to develop an efficient therapeutic approach for virus-associated cancer. Chinese herbal medicine (CHM) has a long history in the treatment of cancer patients in Asian countries. Hedyotis diffusa Willd (Bai Hua She She Cao, BHSSC) is frequently used clinically and has been shown to inhibit tumor growth in vitro. However, in vivo data demonstrating the antitumor efficacy of BHSSC are still lacking. We showed that BHSSC induces murine and human antigen-presenting cell (APC) activation via the MAPK signaling pathway and enhances antigen presentation in bone marrow-derived dendritic cells (BMDCs) in vitro. Furthermore, we identified that treatment with BHSSC leads to improved specific effector and memory T-cell responses in vivo. Variant peptide-based vaccines combined with BHSSC improved antitumor activity in preventive, therapeutic, and recurrent HPV-related tumor models. Furthermore, we showed that rutin, one of the ingredients in BHSSC, induces a strong specific immune response against HPV-related tumors in vivo. In summary, we demonstrated that BHSSC extract and its active compound, rutin, can be used as adjuvants in peptide-based vaccines to increase immunogenicity and to bypass the requirement of a conditional adjuvant.

Plant-derived polysaccharides activate dendritic cell-based anti-cancer immunity

Today, cancers pose a major public health burden. Although a myriad of cancer treatments are available, only a few have achieved clinical efficacy. This is partly attributed to cancers capability to evade host immunity by converting dendritic cells (DCs) from potent stimulators to negative modulators of immunity. Dendritic cell-based immunotherapy attempts to resolve this problem by manipulating the functional characteristics of DCs. Plant-derived polysaccharides (PDPs) can stimulate the maturation of DCs conferring on them the capacity to present internalised tumorigenic antigens to naïve T cells and subsequently priming T cells to eliminate tumours. PDPs have been used as immune modulators and later as anti-cancer agents by Traditional Chinese Medicine practitioners for centuries. They are abundant in nature and form a large group of heterogeneous though structurally related macromolecules that exhibit diverse immunological properties. They can induce antigen pulsed DCs to acquire functional characteristics in vitro which can subsequently be re-introduced into cancer patients. They can also be used as adjuvants in DC-based vaccines or independently for their intrinsic anti-tumour activities. Clinically, some in vitro generated DCs have been shown to be both safe and immunogenic although their clinical application is limited in part by unsatisfactory functional maturation as well as impaired migration to draining lymph nodes where T cells reside. We review the relative potencies of individual PDPs to induce both phenotypic and functional maturation in DCs, their relative abilities to activate anti-cancer immunity, the possible mechanisms by which they act and also the challenges surrounding their clinical application.

Effects of the Ayurved Siriraj Wattana recipe on functional and phenotypic characterization of cytokine-induced killer cells and dendritic cells in vitro

Background

Ayurved Siriraj Wattana recipe (AVS073), has been prescribed as tonic, to increase appetite, and for pain relief. It also exhibits antioxidant, anti-inflammatory, immunomodulating and anti-cancer activities. However, the immunomodulatory effects on antigen-presenting cells and effector T cells remained elusive. We thus aimed to study the effects of AVS073 on differentiation, maturation, functions and proportions of CIK cells and monocyte-derived DCs.

Methods

CIK cells and monocyte-derived DCs were treated with AVS073, followed by the assessment of T-helper (Th) phenotypes using real-time RT-PCR and flow cytometry.

Results

AVS073 promoted Th1 phenotype in CD3⁺CD56⁺ subset of CIK cells through increasing STAT4, T-bet, and interferon-γ. AVS073 inhibited Th2 phenotype through decreasing STAT6. AVS073 inhibited Treg phenotype through decreasing STAT5A, STAT5B and IDO. AVS073 promoted Th17 phenotype through increasing STAT3, RORC and IL-17. AVS073 treatment of mDCs resulted in increasing Th1-prone cytokine (IL-12) and Th17-prone cytokines (IL-6 and IL-23).

Conclusions

AVS073 upregulated Th1 and Th17, but downregulated Th2 and Treg phenotypes within CD3⁺CD56⁺ cells. The treatment of mDCs drove Th1 and Th17-polarizations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1480-7) contains supplementary material, which is available to authorized users.

The immunoregulatory effects of Chinese herbal medicine on the maturation and function of dendritic cells

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese herbal medicine (CHM) has a long-history for treatment of various human diseases including tumors, infection, autoimmune diseases in Asian countries, especially in China, Japan, Korea and India. CHM was traditionally used as water extracts and many Chinese herbs were considered to be good for health, which can regulate immune system to protect host from diseases. With the progress of technology, the components of CHM were identified and purified, which included polysaccharides, saponins, phenolic compounds, flavonoids and so on. Recently, accumulating evidence indicates that CHM and its components can regulate immune system through targeting dendritic cells (DCs). We hereby reviewed the immunoregulatory effects of CHM on the maturation, cytokine production and function of DCs. This should help to shed light on the potential mechanism of CHM to improve the usage and clinical efficacy of CHM.

MATERIALS AND METHODS

Literatures about the effects of CHM on DCs were searched in electronic databases such as Pubmed, Google Scholar and Scopus from 2000 to 2014. 'CHM', 'DC' or 'immune' were used as keywords for the searches. We only reviewed literatures published in English.

RESULTS

Over 600 publications were found about 'CHM&immune' and around 120 literatures about 'CHM&DC' were selected and reviewed in this paper. All publications are backed by preclinical or clinical evidences both in vitro and in vivo. Some CHM and its components promote the maturation, pro-inflammatory cytokine production and function of DCs and as the adjuvant enhance immune responses against tumor and infection. In contrast, other CHM and its components suppress the activation status of DCs to induce regulatory T cells, inhibit allergic and inflammatory responses, ameliorate autoimmune diseases, and prolong the allograft survival. A large body of evidence shows that CHM and its components regulate the activation status of DCs through TLRs, NF-κB, MAPK signaling pathways.

CONCLUSION

This review provides useful information for understanding the mechanism of CHM on the treatment of diseases, which facilitates to improve the efficacy of CHM. Based on the immunoregulatory effects of CHM on DCs, it indicated that some CHM and its components could be use to develop adjuvant to enhance antigen-specific immune responses or tolerogenic adjuvant to generate antigen-specific immune tolerance.

Chemotherapeutic activities of Carthami Flos and its reversal effect on multidrug resistance in cancer cells

Multidrug-resistance (MDR) represents a major cause of failure in cancer chemotherapy. The need for a reduction in MDR by natural-product-based drugs of low toxicity led to the current investigation of applying medicinal herbs in future cancer adjuvant therapy. Carthami Flos (CF), the dried flower of safflower (Carthamus tinctorius L.), is one of the most popular traditional Chinese medicinal herbs used to alleviate pain, increase circulation, and reduce blood-stasis syndrome. The drug resistance index of the total extract of CF in MDR KB-V1 cells and its synergistic effects with other chemotherapeutic agents were studied. SRB cell viability assays were used to quantify growth inhibition after exposure to single drug and in combinations with other chemotherapeutic agents using the median effect principle. The combination indexes were then calculated according to the classic isobologram equation. The results revealed that CF showed a drug resistance index of 0.096. In combination with other chemotherapeutic agents, it enhanced their chemo-sensitivities by 2.8 to 4.0 folds and gave a general synergism in cytotoxic effect. These results indicate that CF could be a potential alternative adjuvant antitumour herbal medicine representing a promising approach to the treatment of some malignant and MDR cancers in the future.