Tannic Acid Exhibits Antiangiogenesis Activity in Nonsmall-Cell Lung Cancer Cells

The Emerging Role of Natural Products in Cancer Treatment

The exploration of natural products as potential agents for cancer treatment has garnered significant attention in recent years. In this comprehensive review, we delve into the diverse array of natural compounds, including alkaloids, carbohydrates, flavonoids, lignans, polyketides, saponins, tannins, and terpenoids, highlighting their emerging roles in cancer therapy. These compounds, derived from various botanical sources, exhibit a wide range of mechanisms of action, targeting critical pathways involved in cancer progression such as cell proliferation, apoptosis, angiogenesis, and metastasis. Through a meticulous examination of preclinical and clinical studies, we provide insights into the therapeutic potential of these natural products across different cancer types. Furthermore, we discuss the advantages and challenges associated with their use in cancer treatment, emphasizing the need for further research to optimize their efficacy, pharmacokinetics, and delivery methods. Overall, this review underscores the importance of natural products in advancing cancer therapeutics and paves the way for future investigations into their clinical applications.

Ferroptosis-related lncRNAs: Distinguishing heterogeneity of the tumour microenvironment and predicting immunotherapy response in bladder cancer

Ferroptosis, a cell death pathway dependent on iron, has been shown in research to play a role in the development, advancement, and outlook of tumours through ferroptosis-related lncRNAs (FRLRs). However, the value of the FRLRs in bladder cancer (BLCA) has not been thoroughly investigated. This research project involved developing a predictive model using ten specific FRLRs (AC099850.4, AL731567.1, AL133415.1, AC021321.1, SPAG5-AS1, HMGA2-AS1, RBMS3-AS3, AC006160.1, AL583785.1, and AL662844.4) through univariate COX and LASSO regression techniques. The validation of this signature as a standalone predictor was confirmed in a group of 65 patients from the urology bladder tumour database at the First Affiliated Hospital of Wenzhou Medical University in Wenzhou, China. Patients were categorized based on their median risk score into either a low-risk group or a high-risk group. Enrichment analysis identified possible molecular mechanisms that could explain the variations in clinical outcomes observed in high-risk and low-risk groups. Moreover, we explored the correlation between FLPS and immunotherapy-related indicators. The ability of FLPS to forecast the effectiveness of immunotherapy was validated by the elevated levels of immune checkpoint genes (PD-L1, CTLA4, and PD-1) in the group at high risk. We also screened the crucial FRLR (HMGA2-AS1) through congruent expression and prognostic conditions and established a ceRNA network, indicating that HMGA2-AS1 may affect epithelial-mesenchymal transition by modulating the Wnt signalling pathway through the ceRNA mechanism. We identified the top five mRNAs (NFIB, NEGR1, JAZF1, JCAD, and ESM1) based on random forest algorithm and analysed the relationship between HMGA2-AS1, the top five mRNAs, and immunotherapy, and their interactions with drug sensitivities. Our results suggest that patients with BLCA have a greater sensitivity to four drugs (dasatinib, pazopanib, erismodegib and olaparib). Our study provides new insights into the TME, key signalling pathways, genome, and potential therapeutic targets of BLCA, with future guidance for immunotherapy and targeted precision drugs.

Cell-homing and immunomodulatory composite hydrogels for effective wound healing with neovascularization

Wound healing in cases of excessive inflammation poses a significant challenge due to compromised neovascularization. Here, we propose a multi-functional composite hydrogel engineered to overcome such conditions through recruitment and activation of macrophages with adapted degradation of the hydrogel. The composite hydrogel (G-TSrP) is created by combining gelatin methacryloyl (GelMA) and nanoparticles (TSrP) composed of tannic acid (TA) and Sr2+. These nanoparticles are prepared using a one-step mineralization process assisted by metal-phenolic network formation. G-TSrP exhibits the ability to eliminate reactive oxygen species and direct polarization of macrophages toward M2 phenotype. It has been observed that the liberation of TA and Sr2+ from G-TSrP actively facilitate the recruitment and up-regulation of the expression of extracellular matrix remodeling genes of macrophages, and thereby, coordinate in vivo adapted degradation of the G-TSrP. Most significantly, G-TSrP accelerates angiogenesis despite the TA's inhibitory properties, which are counteracted by the released Sr2+. Moreover, G-TSrP enhances wound closure under inflammation and promotes normal tissue formation with strong vessel growth. Genetic analysis confirms macrophage-mediated wound healing by the composite hydrogel. Collectively, these findings pave the way for the development of biomaterials that promote wound healing by creating regenerative environment.

Tannic Acid Impedes the Proliferation of Bladder Cancer Cells by Elevating Mitochondrial Pathways of Apoptosis

Bladder cancer stands as a prevailing neoplasm among men globally, distinguished for its pronounced malignancy attributed to invasiveness and metastatic proclivity. Tannic acid (TA), an organic compound in many plants, has garnered recent attention for its discernible anti-mutagenic attributes. This investigation endeavored to scrutinize the repercussions of TA on grade II bladder cancer, with a concerted focus on unraveling its anti-cancer mechanisms. The cytotoxic effects of TA on grade II bladder cancer cells were investigated using multiple techniques, including MTT assay, flow cytometry, TUNEL assay, and western blot. Our findings revealed that elevated concentrations of TA induced cytotoxic effects in grade II bladder cancer cells. Both flow cytometry and the TUNEL assay substantiated the dose-dependent capacity of TA to prompt apoptosis. Western blot analysis corroborated that TA treatment in bladder cancer cells resulted in the upregulation of cleaved caspase-3 expression and PARP. Furthermore, heightened TA dosage elicited an augmentation in the expression of pro-apoptotic proteins, namely Bax and Bak, alongside a reduction in the expression of the anti-apoptotic protein Bcl-2 within bladder cancer cells. This study confirms TA as a potential anticancer agent, demonstrably diminishing the viability of bladder cancer cells. TA exerts cytotoxicity through the activation of mitochondrial apoptotic pathways. Specifically, TA initiates the cleavage of PARP and caspase-3, concurrently augmenting the expression of pro-apoptotic proteins to facilitate apoptosis. Collectively, the present study indicates that TA effectively impedes the proliferation of bladder cancer cells by instigating apoptosis through the intrinsic mitochondrial pathway.

Tannic Acid Incorporated Antibacterial Polyethylene Glycol Based Hydrogel Sponges for Management of Wound Infections

Conventional wound dressings fail to provide features that can assist the healing process of chronic wounds. Multifunctional wound dressings address this issue by incorporating attributes including antibacterial and antioxidant activity, and the ability to enhance wound healing. Herein, polyethylene glycol (PEG)-based antibacterial hydrogel sponge dressings are prepared by a rapid and facile gas foaming method based on an acid chloride/alcohol reaction where tannic acid (TA) is included as a reactant to impart antibacterial efficacy as well as to enhance the mechanical properties of the samples. The results reveal that the TA-integrated sponges possess excellent antibacterial properties against both Escherichia coli and Staphylococcus aureus with approximately 6-8 log reduction in the microbial colony count after 6 h, indicating their high potential for management of infection-prone wounds. Compared to the control sample, TA incorporation increases the elastic modulus by twofold. As the samples also exhibit biocompatibility, antioxidant activity, and wound healing capacity, the novel TA-incorporated hydrogels can be an alternative to traditional wound dressings for wounds with low-to-moderate exudate.

Enhancement of Bone Tissue Regeneration with Multi-Functional Nanoparticles by Coordination of Immune, Osteogenic, and Angiogenic Responses

Inorganic nanoparticles are promising materials for bone tissue engineering due to their chemical resemblance to the native bone structure. However, most studies are unable to capture the entirety of the defective environment, providing limited bone regenerative abilities. Hence, this study aims to develop a multifunctional nanoparticle to collectively control the defective bone niche, including immune, angiogenic, and osteogenic systems. The nanoparticles, self-assembled by biomimetic mineralization and tannic acid (TA)-mediated metal-polyphenol network (MPN), are released sustainably after the incorporation within a gelatin cryogel. The released nanoparticles display a reduction in M1 macrophages by means of reactive oxygen species (ROS) elimination. Consequently, osteoclast maturation is also reduced, which is observed by the minimal formation of multinucleated cells (0.4%). Furthermore, the proportion of M2 macrophages, osteogenic differentiation, and angiogenic potential are consistently increased by the effects of magnesium from the nanoparticles. This orchestrated control of multiple systems influences the in vivo vascularized bone regeneration in which 80% of the critical-sized bone defect is regenerated with new bones with mature lamellar structure and arteriole-scale micro-vessels. Altogether, this study emphasizes the importance of the coordinated modulation of immune, osteogenic, and angiogenic systems at the bone defect site for robust bone regeneration.

Tannins in cancer prevention and therapy

Tannins are a heterogenous class of polyphenolic natural products with promising cancer chemopreventive and therapeutic potential. Studies undertaken over the last 30 years have demonstrated their capacity to target many cellular pathways and molecules important in the development of cancer. Recently, new mechanisms that might be important in anti-carcinogenic activity, such as inhibition of epithelial-to-mesenchymal transition, reduction of cancer stem cell creation, and modulation of cancer cells metabolism have been described. Along with the mechanisms underlying the anti-cancer activity of tannins, this review focuses on their possible application as chemosensitizers in adjuvant therapy and countering multidrug resistance. Furthermore, characteristic physicochemical properties of some tannins, particularly tannic acid, are useful in the formation of nanovehicles for anticancer drugs or the isolation of circulating cancer cells. These new potential applications of tannins deserve further studies. Well-designed clinical trials, which are scarce, are needed to assess the therapeutic effects of tannins themselves or as adjuvants in cancer treatment.

In Vitro Study of the Anti-inflammatory and Antifibrotic Activity of Tannic Acid-Coated Curcumin-Loaded Nanoparticles in Human Tenocytes

Tendinitis is a tendon disorder related to inflammation and pain, due to an injury or overuse of the tissue, which is hypocellular and hypovascular, leading to limited repair which occurs in a disorganized deposition of extracellular matrix that leads to scar formation and fibrosis, ultimately resulting in impaired tendon integrity. Current conventional treatments are limited and often ineffective, highlighting the need for new therapeutic strategies. In this work, acetalated-dextran nanoparticles (AcDEX NPs) loaded with curcumin and coated with tannic acid (TA) are developed to exploit the anti-inflammatory and anti-fibrotic properties of the two compounds. For this purpose, a microfluidic technique was used in order to obtain particles with a precise size distribution, aiming to decrease the batch-to-batch variability for possible future clinical translation. Coating with TA increased not only the stability of the nanosystem in different media but also enhanced the interaction and the cell-uptake in primary human tenocytes and KG-1 macrophages. The nanosystem exhibited good biocompatibility toward these cell types and a good release profile in an inflammatory environment. The efficacy was demonstrated by real-time quantitative polymerase chain reaction, in which the curcumin loaded in the particles showed good anti-inflammatory properties by decreasing the expression of NF-κb and TA-coated NPs showing anti-fibrotic effect, decreasing the gene expression of TGF-β. Overall, due to the loading of curcumin and TA in the AcDEX NPs, and their synergistic activity, this nanosystem has promising properties for future application in tendinitis.

Indocyanine Green-based Glow Nanoparticles Probe for Cancer Imaging

Indocyanine green (ICG) is one of the FDA-approved near infra-red fluorescent (NIRF) probes for cancer imaging and image-guided surgery in the clinical setting. However, the limitations of ICG include poor photostability, high concentration toxicity, short circulation time, and poor cancer cell specificity. To overcome these hurdles, we engineered a nanoconstruct composed of poly (vinyl pyrrolidone) (PVP)-indocyanine green that is cloaked self-assembled with tannic acid (termed as indocyanine green-based glow nanoparticles probe, ICG-Glow NPs) for the cancer cell/tissue-specific targeting. The self-assembled ICG-Glow NPs were confirmed by spherical nanoparticles formation (DLS and TEM) and spectral analyses. The NIRF imaging characteristic of ICG-Glow NPs was established by superior fluorescence counts on filter paper and chicken tissue. The ICG-Glow NPs exhibited excellent hemo and cellular compatibility with human red blood cells, kidney normal, pancreatic normal, and other cancer cell lines. An enhanced cancer-specific NIRF binding and imaging capability of ICG-Glow NPs was confirmed using different human cancer cell lines and human tumor tissues. Additionally, tumor-specific binding/accumulation of ICG-Glow NPs was confirmed in MDA-MB-231 xenograft mouse model. Collectively, these findings suggest that ICG-Glow NPs have great potential as a novel and safe NIRF imaging probe for cancer cell/tumor imaging. This can lead to a quicker cancer diagnosis facilitating precise disease detection and management.

Tannic Acid, A Hydrolysable Tannin, Prevents Transforming Growth Factor-β-Induced Epithelial-Mesenchymal Transition to Counteract Colorectal Tumor Growth

Despite the medico-surgical progress that has been made in the management of patients with colorectal cancer (CRC), the prognosis at five years remains poor. This resistance of cancer cells partly results from their phenotypic characteristics in connection with the epithelial-mesenchymal transition (EMT). In the present study, we have explored the ability of a polyphenol, tannic acid (TA), to counteract CRC cell proliferation and invasion through an action on the EMT. We highlight that TA decreases human SW480 and SW620 CRC cell and murine CT26 CRC cell viability, and TA inhibits their adhesion in the presence of important factors comprising the extracellular matrix, particularly in the presence of collagen type I and IV, and fibronectin. Moreover, these properties were associated with TA's ability to disrupt CRC cell migration and invasion, which are induced by transforming growth factor-β (TGF-β), as evidence in the video microscopy experiments showing that TA blocks the TGF-β1-induced migration of SW480 and CT26 cells. At the molecular level, TA promotes a reversal of the epithelial-mesenchymal transition by repressing the mesenchymal markers (i.e., Slug, Snail, ZEB1, and N-cadherin) and re-expressing the epithelial markers (i.e., E-cadherin and β-catenin). These effects could result from a disruption of the non-canonical signaling pathway that is induced by TGF-β1, where TA strongly decreases the phosphorylation of extracellular-signal regulated kinase ERK1/2, P38 and the AKT proteins that are well known to contribute to the EMT, the cell motility, and the acquisition of invasive properties by tumor cells. Very interestingly, a preclinical study of mice with subcutaneous murine tumor colon CT26 cells has shown that TA was able to significantly delay the growth of tumors without hepato- and nephrotoxicities.