Chlorogenic acid effectively treats cancers through induction of cancer cell differentiation

Targeted delivery of chlorogenic acid by mannosylated liposomes to effectively promote the polarization of TAMs for the treatment of glioblastoma

Tumor-associated macrophages (TAMs) generally display an immunosuppressive M2 phenotype and promote tumor progression and metastasis, suggesting their potential value as a target in cancer immunotherapy. Chlorogenic acid (CHA) has been identified as a potent immunomodulator that promotes the polarization of TAMs from an M2 to an M1 phenotype. However, rapid clearance in vivo and low tumor accumulation have compromised the immunotherapeutic efficacy of CHA in clinical trials. In this study, mannosylated liposomes are developed for targeted delivery of CHA to TAMs. The immunoregulatory effects of CHA, along with the overall antitumor efficacy of CHA-encapsulated mannosylated liposomes, are investigated through in vitro and in vivo experiments. The prepared CHA-encapsulated mannosylated liposomes exhibit an ideal particle size, favorable stability, and preferential accumulation in tumors via the mannose receptor-mediated TAMs-targeting effects. Further, CHA-encapsulated mannosylated liposomes inhibit G422 glioma tumor growth by efficiently promoting the polarization of the pro-tumorigenic M2 phenotype to the anti-tumorigenic M1 phenotype. Overall, these findings indicate that CHA-encapsulated mannosylated liposomes have great potential to enhance the immunotherapeutic efficacy of CHA by inducing a shift from the M2 to the M1 phenotype.

Nettle Tea Inhibits Growth of Acute Myeloid Leukemia Cells In Vitro by Promoting Apoptosis

Urtica dioica (UD), commonly known as "stinging nettle", is a herbaceous flowering plant that is a widely used agent in traditional medicine worldwide. Several formulations of UD leaf extract have been reported to exhibit anti-inflammatory and antioxidant properties, with anticancer potential. The current study investigated the possible anticancer properties of nettle tea, prepared from Urtica dioica leaves, on acute myeloid leukemia (AML) cell lines, and deciphered the underlying molecular mechanisms. Treatment of AML cell lines (U-937 and KG-1) with UD aqueous leaf extract resulted in a dose- and time-dependent inhibition of proliferation, an increase in apoptotic hallmarks such as phosphatidylserine flipping to the outer membrane leaflet, and DNA fragmentation as revealed by cell-death ELISA and cell-cycle analysis assays. Apoptosis induction in U937 cells involves alterations in the expression of Bax and Bcl-2 upon exposure to nettle tea. Furthermore, the chemical composition of UD aqueous extract indicated the presence of multiple chemical agents, such as flavonoids and phenolics, mainly patuletin, m/p-hydroxybenzoic acid, and caffeic acid, among others, to which the pro-apoptotic and anti-tumor effects may be attributed.

Nanostructured Thin Coatings Containing Anthriscus sylvestris Extract with Dual Bioactivity

Plant extracts are highly valuable pharmaceutical complexes recognized for their biological properties, including antibacterial, antifungal, antiviral, antioxidant, anticancer, and anti-inflammatory properties. However, their use is limited by their low water solubility and physicochemical stability. In order to overcome these limitations, we aimed to develop nanostructured carriers as delivery systems for plant extracts; in particular, we selected the extract of Anthriscus sylvestris (AN) on the basis of its antimicrobial effect and antitumor activity. In this study, AN-extract-functionalized magnetite (Fe₃O₄@AN) nanoparticles (NPs) were prepared by the co-precipitation method. The purpose of this study was to synthesize and investigate the physicochemical and biological features of composite coatings based on Fe₃O₄@AN NPs obtained by matrix-assisted pulsed laser evaporation technique. In this respect, laser fluence and drop-casting studies on coatings were performed. The physical and chemical properties of laser-synthesized coatings were investigated by scanning electron microscopy, while Fourier transform infrared spectroscopy comparative analysis was used for determining the chemical structure and functional integrity. Relevant data regarding the presence of magnetic nanoparticles as the only crystalline phase and the size of nanoparticles were obtained by transmission electron microscopy. The in vitro toxicity assessment of the Fe₃O₄@AN showed significant cytotoxic activity against human adenocarcinoma HT-29 cells after prolonged exposure. Antimicrobial results demonstrated that Fe₃O₄@AN coatings inhibit microbial colonization and biofilm formation in clinically relevant bacteria species and yeasts. Such coatings are useful, natural, and multifunctional solutions for the development of tailored medical devices and surfaces.

PML-RARα interaction with TRIB3 impedes PPARγ/RXR function and triggers dyslipidemia in acute promyelocytic leukemia

Although dyslipidemia commonly occurs in patients with acute promyelocytic leukemia (APL) in response to anti-APL therapy, the underlying mechanism and the lipid statuses of patients with newly diagnosed APL remain to be addressed.

Methods: We conducted a retrospective study to investigate the lipid profiles of APL patients. PML-RARα transgenic mice and APL cells-transplanted mice were used to assess the effects of APL cells on the blood/liver lipid levels. Subsequently, gene set enrichment analysis, western blot and dual luciferase reporter assay were performed to examine the role and mechanism of PML-RARα and TRIB3 in lipid metabolism regulation in APL patients at pretreatment and after induction therapy.

Results: APL patients exhibited a higher prevalence of dyslipidemia before anti-APL therapy based on a retrospective study. Furthermore, APL cells caused secretion of triglycerides, cholesterol, and PCSK9 from hepatocytes and degradation of low-density lipoprotein receptors in hepatocytes, which elevated the lipid levels in APL cell-transplanted mice and Pml-Rarα transgenic mice. Mechanistically, pseudokinase TRIB3 interacted with PML-RARα to inhibit PPARγ activity by interfering with the interaction of PPARγ and RXR and promoting PPARγ degradation. Thus, reduced PPARγ activity in APL cells decreased leptin but increased resistin expression, causing lipid metabolism disorder in hepatocytes and subsequent dyslipidemia in mice. Although arsenic/ATRA therapy degraded PML-RARα and restored PPARγ expression, it exacerbated dyslipidemia in APL patients. The elevated TRIB3 expression in response to arsenic/ATRA therapy suppressed PPARγ activity by disrupting the PPARγ/RXR dimer, which resulted in dyslipidemia in APL patients undergoing therapy. Indeed, the PPAR activator not only enhanced the anti-APL effects of arsenic/ATRA by suppressing TRIB3 expression but also reduced therapy-induced dyslipidemia in APL patients.

Conclusion: Our work reveals the critical role of the PML-RARα/PPARγ/TRIB3 axis in the development of dyslipidemia in APL patients, potentially conferring a rationale for combining ATRA/arsenic with the PPAR activator for APL treatment.

Chlorogenic Acid Protects Against Indomethacin-Induced Inflammation and Mucosa Damage by Decreasing Bacteroides-Derived LPS

Background: Chlorogenic acid (CGA), a natural bioactive polyphenol, exerts anti-inflammatory, antioxidant, and antibacterial effects that support the maintenance of intestinal health. However, the influence of CGA on gut microbiota and their metabolites, as well as its potential effects and mechanism of action in inflammatory bowel disease, remain to be elucidated.

Methods: First, an oral gavage was used to administer CGA to indomethacin-treated mice. Then, fecal microbiota transplantation was performed to explore the role of intestinal microbiota in indomethacin-induced inflammation.

Results: CGA treatment protected against body weight loss, damage to intestinal morphology and integrity, inflammation, and alteration of microbiota composition in indomethacin-treated mice. Interestingly, CGA failed to inhibit inflammation or protect intestine integrity in mice treated with antibiotics. Notably, mice who had been colonized with intestinal microbiota from CGA-treated or CGA-and-indomethacin-treated mice, through the fecal microbiota transplantation program, were protected from indomethacin-induced inflammation, growth of Bacteroides, and the accumulation of Bacteroides-derived LPS, in congruence with those who had been treated with CGA.

Conclusion: The results suggest that CGA may protect intestine integrity and alleviate inflammatory responses, primarily by inhibiting the growth of Bacteroides and the accumulation of Bacteroides-derived LPS, in indomethacin-induced colitis. This newly identified mechanism broadens our knowledge of how CGA exerts protective effects on intestinal inflammation and provides strategies for the prevention of gastrointestinal mucosal damage in patients treated with indomethacin.

Kinetic Characterization of Tyrosinase-catalyzed Oxidation of Four Polyphenols

Phenolic compounds such as chlorogenic acid, cryptochlorogenic acid, neochlorogenic acid and caffeic acid are widely distributed in fruits, vegetables and traditional Chinese medicines with a wide range of biological activities. Tyrosinase plays a critical role in the food industry, but recent studies have proposed unexplored aspects of clinical application. Tyrosinase-catalyzed oxidation of four polyphenols as well as its underlying mechanism remains unclear. In the current work, we investigated the kinetic properties of tyrosinase-catalyzed oxidation of the four polyphenols of interest. To measure the unstable o-quinone products, an analytical method using 3-methyl-2-benzothiazolinone hydrazone (MBTH) was established. The optimal incubation time, buffer pH, temperature and enzyme concentration for the enzyme activity in the presence of each polyphenol of interest were investigated. Under the final optimized conditions, the kinetics and substrate specificity of four polyphenols were examined. Kinetic data showed that tyrosinase had the greatest substrate affnity to chlorogenic acid compared with its isomers and caffeic acid. The catalytic effciency with chlorogenic acid was 8- to 15-fold higher than that with the other 3 polyphenols. Molecular docking study demonstrated that the tight binding of chlorogenic acid at the peripheral site should be the major reason for the specifcity to chlorogenic acid. In light of this, the rational design of high-affnity inhibitors against tyrosinase may focus on the binding of both the Cu site and peripheral site. This study will supply a basis for the selection of phenolic acids in food industry and health care.