Curcumin inhibits lymphangiogenesis in vitro and in vivo

Lymphatic vessel: origin, heterogeneity, biological functions, and therapeutic targets

Lymphatic vessels, comprising the secondary circulatory system in human body, play a multifaceted role in maintaining homeostasis among various tissues and organs. They are tasked with a serious of responsibilities, including the regulation of lymph absorption and transport, the orchestration of immune surveillance and responses. Lymphatic vessel development undergoes a series of sophisticated regulatory signaling pathways governing heterogeneous-origin cell populations stepwise to assemble into the highly specialized lymphatic vessel networks. Lymphangiogenesis, as defined by new lymphatic vessels sprouting from preexisting lymphatic vessels/embryonic veins, is the main developmental mechanism underlying the formation and expansion of lymphatic vessel networks in an embryo. However, abnormal lymphangiogenesis could be observed in many pathological conditions and has a close relationship with the development and progression of various diseases. Mechanistic studies have revealed a set of lymphangiogenic factors and cascades that may serve as the potential targets for regulating abnormal lymphangiogenesis, to further modulate the progression of diseases. Actually, an increasing number of clinical trials have demonstrated the promising interventions and showed the feasibility of currently available treatments for future clinical translation. Targeting lymphangiogenic promoters or inhibitors not only directly regulates abnormal lymphangiogenesis, but improves the efficacy of diverse treatments. In conclusion, we present a comprehensive overview of lymphatic vessel development and physiological functions, and describe the critical involvement of abnormal lymphangiogenesis in multiple diseases. Moreover, we summarize the targeting therapeutic values of abnormal lymphangiogenesis, providing novel perspectives for treatment strategy of multiple human diseases.

Curcumin and analogues against head and neck cancer: From drug delivery to molecular mechanisms

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most life-threatening diseases which also causes economic burden worldwide. To overcome the limitations of traditional therapies, investigation into alternative adjuvant treatments is crucial.

PURPOSE

Curcumin, a turmeric-derived compound, demonstrates significant therapeutic potential in diverse diseases, including cancer. Furthermore, research focuses on curcumin analogues and novel drug delivery systems, offering approaches for improved efficacy. This review aims to provide a comprehensive overview of curcumin's current findings, emphasizing its mechanisms of anti-HNSCC effects and potential for clinical application.

METHOD

An electronic search of Web of Science, MEDLINE, and Embase was conducted to identify literature about the application of curcumin or analogues in HNSCC. Titles and abstracts were screened to identify potentially eligible studies. Full-text articles will be obtained and independently evaluated by two authors to make the decision of inclusion in the review.

RESULTS

Curcumin's clinical application is hindered by poor bioavailability, prompting the exploration of methods to enhance it, such as curcumin analogues and novel drug delivery systems. Curcumin could exhibit anti-cancer effects by targeting cancer cells and modulating the tumor microenvironment in HNSCC. Mechanisms of action include cell cycle arrest, apoptosis promotion, reactive oxygen species induction, endoplasmic reticulum stress, inhibition of epithelial-mesenchymal transition, attenuation of extracellular matrix degradation, and modulation of tumor metabolism in HNSCC cells. Curcumin also targets various components of the tumor microenvironment, including cancer-associated fibroblasts, innate and adaptive immunity, and lymphovascular niches. Furthermore, curcumin enhances the anti-cancer effects of other drugs as adjunctive therapy. Two clinical trials report its potential clinical applications in treating HNSCC.

CONCLUSION

Curcumin has demonstrated therapeutic potential in HNSCC through in vitro and in vivo studies. Its effectiveness is attributed to its ability to modulate cancer cells and interact with the intricate tumor microenvironment. The development of curcumin analogues and novel drug delivery systems has shown promise in improving its bioavailability, thereby expanding its clinical applications. Further research and exploration in this area hold great potential for harnessing the full therapeutic benefits of curcumin in HNSCC treatment.

Antitumor Effects of Curcumin on Cervical Cancer with the Focus on Molecular Mechanisms: An Exegesis

Cervical cancer is one of the most prevalent malignancies among females and is correlated with a significant fatality rate. Chemotherapy is the most common treatment for cervical cancer; however, it has a low success rate due to significant side effects and the incidence of chemo-resistance. Curcumin, a polyphenolic natural compound derived from turmeric, acts as an antioxidant by diffusing across cell membranes into the endoplasmic reticulum, mitochondria, and nucleus, where it performs its effects. As a result, it's been promoted as a chemo-preventive, anti-metastatic, and anti-angiogenic agent. As a consequence, the main goal of the present review was to gather research information that looked at the link between curcumin and its derivatives against cervical cancer.

Complexity of Tumor Microenvironment: Therapeutic Role of Curcumin and Its Metabolites

The tumor microenvironment (TME) is a complex network of cellular and non-cellular components surrounding the tumor. The cellular component includes fibroblasts, adipocytes, endothelial cells, and immune cells, while non-cellular components are tumor vasculature, extracellular matrix and signaling molecules. The tumor cells have constant close interaction with their surrounding TME components that facilitate their growth, survival, and metastasis. Targeting a complex TME network and its interaction with the tumor can offer a novel strategy to disrupt cancer cell progression. Curcumin, from turmeric rhizome, is recognized as a safe and effective natural therapeutic agent against multiple diseases including cancer. Here the effects of curcumin and its metabolites on tumor-TME interaction modulating ability have been described. Curcumin and its metabolites regulate TME by inhibiting the growth of its cellular components such as cancer-associated adipocytes, cancer-associated fibroblast, tumor endothelial cells, tumor-stimulating immune cells, and inducing anticancer immune cells. They also inhibit the interplay of tumor cells to TME by suppressing non-cellular components such as extracellular matrix, and associated tumor promoting signaling-pathways. In addition, curcumin inhibits the inflammatory environment, suppresses angiogenic factors, and increases antioxidant status in TME. Overall, curcumin has the capability to regulate TME components and their interaction with tumor cells.

Physiologically relevant curcuminoids inhibit angiogenesis via VEGFR2 in human aortic endothelial cells

Angiogenesis is a complex process encompassing endothelial cell proliferation, migration, and tube formation. While numerous studies describe that curcumin exerts antitumor properties (e.g., targeting angiogenesis), information regarding other dietary curcuminoids such as demethoxycurcumin (DMC) and bisdemethoxycurcumin (BisDMC) is scant. In this study, we evaluated the antiangiogenic activities of these three curcuminoids at physiological concentrations (0.1-5 μM) on endothelial cell migration and tubulogenesis and the underlying associated mechanisms on human aortic endothelial cells (HAECs). Results showed that the individual compounds and a representative mixture inhibited the tubulogenic and migration capacity of endothelial cells dose-dependently, while sparing cell viability. Notably, DMC and BisDMC at 0.1 and 1 μM showed higher capacity than curcumin inhibiting tubulogenesis. These compounds also reduced phosphorylation of the VEGFR2 and the downstream ERK and Akt pathways in VEGF₁₆₅-stimulated cells. In silico analysis showed that curcuminoids could bind the VEGFR2 antagonizing the VEGF-mediated angiogenesis. These findings suggest that physiologically concentrations of curcuminoids might counteract pro-angiogenic stimuli relevant to tumorigenic processes.

HMGB1 Promotes Lymphangiogenesis through the Activation of RAGE on M2 Macrophages in Laryngeal Squamous Cell Carcinoma

Background. Receptor for advanced glycation end products (RAGE) is implicated in tumor biology. Released high mobility group box protein 1 (HMGB1) ligand binding to RAGE receptor in tumor cells promotes tumor progression. The mechanisms of HMGB1-RAGE signaling in M2 macrophages involved in lymphangiogenesis in laryngeal carcinoma remain poorly understood. Here, we assessed the effect of HMGB1-RAGE signaling on M2 macrophages in lymphangiogenesis. Methods. HMGB1, CD163, and D2-40 in laryngeal squamous cell carcinoma (LSCC, $n=123$ ), laryngeal precursor lesions (LPLs, $n=102$ ), and vocal polyp (VP, $n=55$ ) were analyzed by immunohistochemistry. THP-1 cell-expressed RAGE gene was knocked down and then polarized to M0 macrophages and M2 macrophages. IL-23, TNF-α, TGF-β, and IL-10 were measured by ELISA; IL-1β, IL-12, IL-10, and CCL-13 were evaluated by RT-qPCR, and CD206, CD163, and RAGE were evaluated by western blot to evaluate whether classical M2 macrophages were obtained. Conditioned media from RAGE+/- M0 macrophages and RAGE+/- M2 macrophages incubated in the presence or absence of HMGB1, anti-Toll-like receptor (TLR)2, anti-TLR4 antibodies, and anti-VEGF-C antibodies were collected separately for human dermal lymphatic endothelial cells (HDLEC) for proliferation, migration, lymphangiogenesis assay, and VEGF-C concentration analysis. Results. HMGB1 and M2 macrophage densities were increased in LSCC ( $P<0.01$ ). HMGB1 and M2 macrophage densities were significantly correlated with lymphatic vessel density (LVD) in LSCC ( $P<0.01$ ). The HMGB1 overexpression and higher M2 macrophage density were involved in lymph node metastasis ( $P<0.01$ ) and poor prognosis ( $P<0.05$ ). In vitro, conditioned medium from HMGB1-stimulated RAGE+ M2 macrophages activated lymphangiogenesis by upregulating the VEGF compared to controls ( $P<0.05$ ). On the contrary, RAGE knockdown obviously decreased the corresponding effects of HMGB1-preconditioned M2 macrophages upon HDLEC ( $P<0.05$ ). HMGB1-TLR pathway does not significantly increase HDLEC proliferation, migration, and lymphangiogenesis on M2 macrophages. Conclusions. HMGB1 promotes lymphangiogenesis by activation of RAGE on M2 macrophages. Targeting RAGE may provide an effective therapeutic strategy against M2 macrophages in LSCC patients with lymph node metastasis.

Nutraceuticals and their role in tumor angiogenesis

Angiogenesis plays a pivotal role in cancer initiation, maintenance, and progression. Diet may inhibit, retard or reverse these processes affecting angiogenesis (angioprevention). Nutraceuticals, such as omega-3 fatty acids, amino acids, proteins, vitamins, minerals, fibers, and phenolic compounds, improve health benefits as they are a source of bioactive compounds that, among other effects, can regulate angiogenesis. The literature concerning the pro-angiogenic and/or anti-angiogenic nutraceuticals and the possible activated pathways in cancer and other non-neoplastic diseases by in vivo and in vitro experiments are reviewed.

3,4-Difluorobenzocurcumin Inhibits Vegfc-Vegfr3-Erk Signalling to Block Developmental Lymphangiogenesis in Zebrafish

Lymphangiogenesis, the formation of new lymphatic vessels from pre-existing vasculature, plays critical roles in disease, including in cancer metastasis and chronic inflammation. Preclinical and recent clinical studies have now demonstrated therapeutic utility for several anti-lymphangiogenic agents, but optimal agents and efficacy in different settings remain to be determined. We tested the anti-lymphangiogenic property of 3,4-Difluorobenzocurcumin (CDF), which has previously been implicated as an anti-cancer agent, using zebrafish embryos and cultured vascular endothelial cells. We used transgenic zebrafish labelling the lymphatic system and found that CDF potently inhibits lymphangiogenesis during embryonic development. We also found that the parent compound, Curcumin, does not inhibit lymphangiogenesis. CDF blocked lymphatic and venous sprouting, and lymphatic migration in the head and trunk of the embryo. Mechanistically, CDF impaired VEGFC-VEGFR3-ERK signalling in vitro and in vivo. In an in vivo pathological model of Vegfc-overexpression, treatment with CDF rescued endothelial cell hyperplasia. CDF did not inhibit the kinase activity of VEGFR3 yet displayed more prolonged activity in vivo than previously reported kinase inhibitors. These findings warrant further assessment of CDF and its mode of action as a candidate for use in metastasis and diseases of aberrant lymphangiogenesis.

Plant Natural Products: Promising Resources for Cancer Chemoprevention

Cancer is a major factor threatening human health and life safety, and there is a lack of safe and effective therapeutic drugs. Intervention and prevention in premalignant process are effective ways to reverse carcinogenesis and prevent cancer from occurring. Plant natural products are rich in sources and are a promising source for cancer chemoprevention. This article reviews the chemopreventive effects of natural products, especially focused on polyphenols, flavonoids, monoterpene and triterpenoids, sulfur compounds, and cellulose. Meanwhile, the main mechanisms include induction of apoptosis, antiproliferation and inhibition of metastasis are briefly summarized. In conclusion, this article provides evidence for natural products remaining a prominent source of cancer chemoprevention.

Traditional Chinese Medicine Regulating Lymphangiogenesis: A Literature Review

Lymphatic vessels, as an important part of the lymphatic system, form a fine vascular system in humans and play an important role in regulating fluid homeostasis, assisting immune surveillance and transporting dietary lipids. Dysfunction of lymphatic vessels can cause many diseases, including cancer, cardiovascular diseases, lymphedema, inflammation, rheumatoid arthritis. Research on lymphangiogenesis has become increasingly important over the last few decades. Nevertheless, the explicit role of regulating lymphangiogenesis in preventing and treating diseases remains unclear owing to the lack of a deeper understanding of the cellular and molecular pathways of the specific and tissue-specific changes in lymphangiopathy. TCM, consisting of compound extracted from TCM, Injections of single TCM and formula, is an important complementary strategy for treating disease in China. Lots of valuable traditional Chinese medicines are used as substitutes or supplements in western countries. As one of the main natural resources, these TCM are widely used in new drug research and development in Asia. Moreover, as a historical and cultural heritage, TCM has been widely applied to clinical research on lymphangiogenesis leveraging new technologies recently. Available studies show that TCM has an explicit effect on the regulation of lymphatic regeneration. This review aims to clarify the function and mechanisms, especially the inhibitory effect of TCM in facilitating and inhibiting lymphatic regeneration.

l-Arginine/l-lysine functionalized chitosan–casein core–shell and pH-responsive nanoparticles: fabrication, characterization and bioavailability enhancement of hydrophobic and hydrophilic bioactive compounds

This study developed novel oral delivery systems for the encapsulation, protection, and controlled release of hydrophobic and hydrophilic bioactive compounds based on l-arginine- or l-lysine-functionalized chitosan–casein nanoparticles.

Curcumin: Recent Advances in the Development of Strategies to Improve Oral Bioavailability

Substantial human and preclinical studies have shown that curcumin, a dietary compound from turmeric, has a variety of health-promoting effects including but not limited to antioxidant, antimicrobial, anti-inflammatory, and anticancer actions. However, curcumin has poor bioavailability, and high doses of curcumin are usually needed to exert its health-promoting effects in vivo, limiting its applications for disease prevention. Here, we discuss the health-promoting effects of curcumin, factors limiting its bioavailability, and strategies to improve its oral bioavailability.

Protective effect and related mechanisms of curcumin in rat experimental periodontitis

Background

Curcumin exhibits anti-inflammatory effects and has been suggested as a treatment for inflammatory diseases. The aim of this study was to investigate the effects of curcumin on the lipopolysaccharide induced inflammatory response in rat gingival fibroblasts in vitro and ligation-induced experimental periodontitis in vivo, and to speculate the possible anti-inflammatory mechanism of curcumin.

Methods

The gingival fibroblasts were incubated with different concentrations of curcumin in the absence or presence of lipopolysaccharide (LPS). Concentrations of interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG) and soluble receptor activator of nuclear factor kappa-B ligand (RANKL) culture supernatants of rat gingival fibroblasts were determined by enzyme linked immunosorbent assay. The nuclear fraction of rat gingival fibroblasts was extracted and nuclear factor kappa-B (NF-κB) activation was assessed by western blotting to elucidate related mechanisms. Curcumin was given every two days by oral gavage. The gingival inflammation and alveolar bone loss between the first and second molars were observed by hematoxylin and eosin staining. Collagen fibers were observed by picro-sirius red staining. Alveolar bone loss was assessed by micro-CT analysis.

Results

Curcumin attenuated the production of IL-1β and TNF-α in rat gingival fibroblasts stimulated by LPS, and inhibited the LPS-induced decrease in OPG/sRANKL ratio and NF-κB activation. Curcumin significantly reduced gingival inflammation and modulated collagen fiber and alveolar bone loss in vivo.

Conclusions

curcumin modulates inflammatory activity in rat periodontitis by inhibiting NF-κB activation and decreasing the OPG/sRANKL ratio induced by LPS.

Metastatic genes targeted by an antioxidant in an established radiation- and estrogen-breast cancer model

Breast cancer remains the second most common disease worldwide. Radiotherapy, alone or in combination with chemotherapy, is widely used after surgery as a treatment for cancer with proven therapeutic efficacy manifested by reduced incidence of loco-regional and distant recurrences. However, clinical evidence indicates that relapses occurring after radiotherapy are associated with increased metastatic potential and poor prognosis in the breast. Among the anticarcinogenic and antiproliferative agents, curcumin is a well-known major dietary natural yellow pigment derived from the rhizome of the herb Curcuma longa (Zingiberaceae). The aim of the present study was to analyze the differential expression of metastatic genes in radiation- and estrogen-induced breast cancer cell model and the effect of curcumin on such metastatic genes in breast carcinogenesis. Expression levels of TGF-α and TGFβ1 genes were upregulated in MCF-10F and downregulated in Tumor2 cell lines treated with curcumin. Expression levels of other genes such as caspase 9 and collagen 4 A2 were upregulated in both MCF-10F and Tumor2-treated cell lines. Integrin α5 and cathepsin B and D decreased its expression in Tumor2, whereas E-Cadherin, c-myc and CD44 expressions were only increased in MCF-10F. It can be concluded that metastatic genes can be affected by curcumin in cancer progression and such substance can be used in breast cancer patients with advanced disease without side-effects commonly observed with therapeutic drugs.

Potential roles of chemical degradation in the biological activities of curcumin

Substantial pre-clinical and human studies have shown that curcumin, a dietary compound from turmeric, has a variety of health-promoting biological activities. A better understanding of the biochemical mechanisms for the health-promoting effects of curcumin could facilitate the development of effective strategies for disease prevention. Recent studies have shown that in aqueous buffer, curcumin rapidly degrades and leads to formation of various degradation products. In this review, we summarized and discussed the biological activities of chemical degradation products of curcumin, including alkaline hydrolysis products (such as ferulic acid, vanillin, ferulaldehyde, and feruloyl methane), and autoxidation products (such as bicyclopentadione). Though many of these degradation products are biologically active, they are substantially less-active compared to curcumin, supporting that chemical degradation has a limited contribution to the biological activities of curcumin.

Kallistatin exerts anti-lymphangiogenic effects by inhibiting lymphatic endothelial cell proliferation, migration and tube formation

Kallistatin has been recognized as an endogenous angiogenic inhibitor. However, its effects on lymphatic endothelial cells and lymphangiogenesis remain poorly understood. Lymphangiogenesis is involved in tumor metastasis via the lymphatic vasculature in various types of tumors. The aim of this study was to investigate the effects of kallistatin on lymphangiogenesis and the mechanism of action involved. Treatment with kallistatin recombinant protein or overexpression of kallistatin inhibited the proliferation, migration and tube formation of human lymphatic endothelial cells (hLECs), and induced apoptosis of hLECs. Furthermore, our results showed that the lymphatic vessel density (LVD) was reduced in lung and stomach sections from kallistatin-overexpressing transgenic mice. Treatment with kallistatin recombinant protein decreased the LVD in the implanted gastric xenograft tumors of nude mice. To the best of our knowledge, the present study is the first to demonstrate that kallistatin possesses anti-lymphangiogenic activity in vitro and in vivo. Moreover, kallistatin inhibited proliferation and migration of hLECs by reducing the phosphorylation of ERK and Akt, respectively. These findings suggested that kallistatin may be a promising agent that could be used to suppress cancer metastasis by inhibiting both angiogenesis and lymphangiogenesis.

Modeling pre-metastatic lymphvascular niche in the mouse ear sponge assay

Lymphangiogenesis, the formation of new lymphatic vessels, occurs in primary tumors and in draining lymph nodes leading to pre-metastatic niche formation. Reliable in vivo models are becoming instrumental for investigating alterations occurring in lymph nodes before tumor cell arrival. In this study, we demonstrate that B16F10 melanoma cell encapsulation in a biomaterial, and implantation in the mouse ear, prevents their rapid lymphatic spread observed when cells are directly injected in the ear. Vascular remodeling in lymph nodes was detected two weeks after sponge implantation, while their colonization by tumor cells occurred two weeks later. In this model, a huge lymphangiogenic response was induced in primary tumors and in pre-metastatic and metastatic lymph nodes. In control lymph nodes, lymphatic vessels were confined to the cortex. In contrast, an enlargement and expansion of lymphatic vessels towards paracortical and medullar areas occurred in pre-metastatic lymph nodes. We designed an original computerized-assisted quantification method to examine the lymphatic vessel structure and the spatial distribution. This new reliable and accurate model is suitable for in vivo studies of lymphangiogenesis, holds promise for unraveling the mechanisms underlying lymphatic metastases and pre-metastatic niche formation in lymph nodes, and will provide new tools for drug testing.