Natural products targeting tumour angiogenesis

Coumarins in Anticancer Therapy: Mechanisms of Action, Potential Applications and Research Perspectives

Coumarins are natural organic compounds widely found in plants that show promising anticancer properties. This article reviews the current research on the mechanisms of action of coumarins in cancer therapy, including the induction of apoptosis, inhibition of tumor cell proliferation, modulation of oxidative stress, and inhibition of angiogenesis and metastasis. Examples of coumarins with demonstrated anticancer activity, such as scopoletin, umbeliferon, esculetin and their synthetic derivatives, are also presented. The results of preclinical studies, the potential use of coumarins as stand-alone drugs and their role in combination therapy with chemotherapy are discussed. In addition, challenges related to bioavailability, safety and potential interactions with other drugs are highlighted. This review concludes by pointing out future research directions, such as the design of new coumarin analogs and the use of nanotechnology to enhance their efficacy in cancer treatment.

Natural products and cancer: From drug discovery to prevention and therapy

LINKED ARTICLES

This article is part of a themed issue Natural Products and Cancer: From Drug Discovery to Prevention and Therapy. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.10/issuetoc.

Injectable polydopamine/curcumin dual-modified polylactic acid/polycaprolactone coaxial staple fibers for chronotropic treatment of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most prevalent malignant tumors in the oral and maxillofacial region. Traditional treatments for OSCC, including surgery, radiotherapy, and chemotherapy, often lead to severe adverse effects. Therefore, the development of safe and effective novel cancer therapies is crucial for achieving synergistic cancer treatment, significantly enhancing patient survival and quality of life. In this study, triaxial electrospinning combined with freeze-shortening technology was employed to prepare injectable short fibers that provided a sustained release of curcumin (CUR). Subsequently, polydopamine (PDA) was modified on the surface of the short fibers to create PDA@CUR@PCL/PLA. The developed injectable short fibers represented a significant advancement in reducing the risks associated with the surgical implantation of traditional two-dimensional fibrous membranes. These fibers were coated with dopamine, which imparted notable significant photothermal effects, facilitating the rapid destruction of cancer cells. Furthermore, the core-loaded CUR was released in a pH-responsive manner and demonstrated a sustained anti-tumor effect. Cellular and animal experiments indicated that these composite short fibers could effectively eliminate oral cancer cells through a synergistic combination of photothermal and drug therapies without apparent toxic side effects. The developed injectable coaxial PDA@CUR@PCL/PLA short fibers are expected to provide a novel treatment approach for OSCC.

In Vivo and Clinical Studies of Natural Products Targeting the Hallmarks of Cancer

Despite more than 200 approved anticancer agents, cancer remains a leading cause of death worldwide due to disease complexity, tumour heterogeneity, drug toxicity, and the emergence of drug resistance. Accordingly, the development of chemotherapeutic agents with higher efficacy, a better safety profile, and the capability of bypassing drug resistance would be a cornerstone in cancer therapy. Natural products have played a pivotal role in the field of drug discovery, especially for the pharmacotherapy of cancer, infectious, and chronic diseases. Owing to their distinctive structures and multiple mechanistic activities, natural products and their derivatives have been utilized for decades in cancer treatment protocols. In this review, we delve into the potential of natural products as anticancer agents by targeting cancer's hallmarks, including sustained proliferative signalling, evading growth suppression, resisting apoptosis and cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis. We highlight the molecular mechanisms of some natural products, in vivo studies, and promising clinical trials. This review emphasizes the significance of natural products in fighting cancer and the need for further studies to uncover their fully therapeutic potential.

Epigallocatechin-3-gallate therapeutic potential in human diseases: molecular mechanisms and clinical studies

Green tea has garnered increasing attention across age groups due to its numerous health benefits, largely attributed to Epigallocatechin 3-gallate (EGCG), its key polyphenol. EGCG exhibits a wide spectrum of biological activities, including antioxidant, anti-inflammatory, antibacterial, anticancer, and neuroprotective properties, as well as benefits for cardiovascular and oral health. This review provides a comprehensive overview of recent findings on the therapeutic potential of EGCG in various human diseases. Neuroprotective effects of EGCG include safeguarding neurons from damage and enhancing cognitive function, primarily through its antioxidant capacity to reduce reactive oxygen species (ROS) generated during physiological stress. Additionally, EGCG modulates key signaling pathways such as JAK/STAT, Delta-Notch, and TNF, all of which play critical roles in neuronal survival, growth, and function. Furthermore, EGCG is involved in regulating apoptosis and cell cycle progression, making it a promising candidate for the treatment of metabolic diseases, including cancer and diabetes. Despite its promising therapeutic potential, further clinical trials are essential to validate the efficacy and safety of EGCG and to optimize its delivery to target tissues. While many reviews have addressed the anticancer properties of EGCG, this review focuses on the molecular mechanisms and signaling pathways by which EGCG used in specific human diseases, particularly cancer, neurodegenerative and metabolic diseases. It serves as a valuable resource for researchers, clinicians, and healthcare professionals, revealing the potential of EGCG in managing neurodegenerative disorders, cancer, and metabolic diseases and highlighting its broader therapeutic values.

The role of N6-methyladenosine modification in tumor angiogenesis

Tumor angiogenesis is a characteristics of malignant cancer progression that facilitates cancer cell growth, diffusion and metastasis, and has an indispensable role in cancer development. N6-methyladenosine (m6A) is among the most prevalent internal modifications in eukaryotic RNAs, and has considerable influence on RNA metabolism, including its transcription, splicing, localization, translation, recognition, and degradation. The m6A modification is generated by m6A methyltransferases ("writers"), removed by m6A demethylases ("erasers"), and recognized by m6A-binding proteins ("readers"). There is accumulating evidence that abnormal m6A modification is involved in the pathogenesis of multiple diseases, including cancers, and promotes cancer occurrence, development, and progression through its considerable impact on oncoprotein expression. Furthermore, increasing studies have demonstrated that m6A modification can influence angiogenesis in cancers through multiple pathways to regulate malignant processes. In this review, we elaborate the role of m6A modification in tumor angiogenesis-related molecules and pathways in detail, providing insights into the interactions between m6A and tumor angiogenesis. Moreover, we describe how targeting m6A modification in combination with anti-angiogenesis drugs is expected to be a promising anti-tumor treatment strategy, with potential value for addressing the challenge of drug resistance.

Natural products‐based antiangiogenic agents: New frontiers in cancer therapy

Angiogenesis, vital for tumor growth and metastasis, is a promising target in cancer therapy. Natural compounds offer potential as antiangiogenic agents with reduced toxicity. This review provides a comprehensive overview of natural product‐based antiangiogenic therapies, focusing on molecular mechanisms and therapeutic potential. A systematic search identified relevant articles from 2019 to 2023. Various natural compounds, including polyphenols, terpenes, alkaloids, cannabinoids, omega‐3 fatty acids, polysaccharides, proteins, and carotenoids, were investigated for their antiangiogenic properties. Challenges such as dose standardization, routes of administration, and potential side effects remain. Further studies, including in‐depth animal models and human epidemiological studies, must elucidate clinical efficacy and safety. Synergistic effects with current antiangiogenic therapies, such as bevacizumab and tyrosine kinase inhibitors, should be explored. Additionally, the potential hormone‐dependent effects of compounds like genistein highlight the need for safety evaluation. In conclusion, natural products hold promise as adjunctive therapies to conventional antineoplastic drugs in modulating angiogenesis in cancer. However, robust clinical trials are needed to validate preclinical findings and ensure safety and efficacy.

Herbal Therapies for Cancer Treatment: A Review of Phytotherapeutic Efficacy

Natural products have proven to be promising anti-cancer agents due to their diverse chemical structures and bioactivity. This review examines their central role in cancer treatment, focusing on their mechanisms of action and therapeutic benefits. Medicinal plants contain bioactive compounds, such as flavonoids, alkaloids, terpenoids and polyphenols, which exhibit various anticancer properties. These compounds induce apoptosis, inhibit cell proliferation and cell cycle progression, interfere with microtubule formation, act on topoisomerase targets, inhibit angiogenesis, modulate key signaling pathways, improve the tumor microenvironment, reverse drug resistance and activate immune cells. Herbal anti-cancer drugs offer therapeutic advantages, particularly selective toxicity against cancer cells, reducing the adverse side effects associated with conventional chemotherapy. Recent studies and clinical trials highlight the benefits of herbal medicines in alleviating side effects, improving tolerance to chemotherapy and the occurrence of synergistic effects with conventional treatments. For example, the herbal medicine SH003 was found to be safe and potentially effective in the treatment of solid cancers, while Fucoidan showed anti-inflammatory properties that are beneficial for patients with advanced cancer. The current research landscape on herbal anticancer agents is extensive. Numerous studies and clinical trials are investigating their efficacy, safety and mechanisms of action in various cancers such as lung, prostate, breast and hepatocellular carcinoma. Promising developments include the polypharmacological approach, combination therapies, immunomodulation and the improvement of quality of life. However, there are still challenges in the development and use of natural products as anti-cancer drugs, such as the need for further research into their mechanisms of action, possible drug interactions and optimal dosage. Standardizing herbal extracts, improving bioavailability and delivery, and overcoming regulatory and acceptance hurdles are critical issues that need to be addressed. Nonetheless, the promising anticancer effects and therapeutic benefits of natural products warrant further investigation and development. Multidisciplinary collaboration is essential to advance herbal cancer therapy and integrate these agents into mainstream cancer treatment.

Complications and comorbidities associated with antineoplastic chemotherapy: Rethinking drug design and delivery for anticancer therapy

Despite the considerable advancements in chemotherapy as a cornerstone modality in cancer treatment, the prevalence of complications and pre-existing diseases is on the rise among cancer patients along with prolonged survival and aging population. The relationships between these disorders and cancer are intricate, bearing significant influence on the survival and quality of life of individuals with cancer and presenting challenges for the prognosis and outcomes of malignancies. Herein, we review the prevailing complications and comorbidities that often accompany chemotherapy and summarize the lessons to learn from inadequate research and management of this scenario, with an emphasis on possible strategies for reducing potential complications and alleviating comorbidities, as well as an overview of current preclinical cancer models and practical advice for establishing bio-faithful preclinical models in such complex context.

Liensinine diperchlorate and artemisitene synergistically attenuate breast cancer progression through suppressing PI3K-AKT signaling and their efficiency in breast cancer patient-derived organoids

Breast cancer (BC) is the most prevalent cancer among women around the world. Finding new and efficient drugs has become a crucial aspect of BC treatment. Liensinine diperchlorate (LIN) and artemisitene (ATT) are natural compounds with potential anti-cancer activities extracted from lotus (Nelumbo nucifera Gaertn) seeds and Artemisia annua, respectively. However, the synergistic anti-breast cancer effectiveness and mechanism of LIN and ATT remain unknown. This study intended to reveal the biological functions and underlying mechanism of combined LIN and ATT treatment in BC. Herein, we first reported that LIN and ATT synergistically mitigated the proliferation, migration as well as invasion of BC cells. Besides, LIN boosted the stimulatory effect of ATT on reactive oxygen species (ROS)-mediated apoptosis in BC cells. Interestingly, LIN and ATT synergistically attenuated the growth of BC patient-derived organoids. Moreover, LIN augmented the inhibitory efficacy of ATT on BC growth in vivo without obvious side effects. Furthermore, the inactivation of PI3K-AKT pathway and its regulated proteins contributed to the therapeutic role of LIN and ATT treatment in BC. Intriguingly, a prediction model constructed as per RNA sequencing data indicated that the combination of LIN and ATT treatment might ameliorate the prognosis of BC patients. In conclusion, our present investigation demonstrated that LIN and ATT synergistically inhibited BC cell proliferation, migration as well as invasion and enhanced ROS-mediated apoptosis via suppressing the PI3K-AKT signaling, and suggested that combining LIN and ATT treatment might be a promising choice for BC therapy.

Survival strategies: How tumor hypoxia microenvironment orchestrates angiogenesis

During tumor development, the tumor itself must continuously generate new blood vessels to meet their growth needs while also allowing for tumor invasion and metastasis. One of the most common features of tumors is hypoxia, which drives the process of tumor angiogenesis by regulating the tumor microenvironment, thus adversely affecting the prognosis of patients. In addition, to overcome unsuitable environments for growth, such as hypoxia, nutrient deficiency, hyperacidity, and immunosuppression, the tumor microenvironment (TME) coordinates angiogenesis in several ways to restore the supply of oxygen and nutrients and to remove metabolic wastes. A growing body of research suggests that tumor angiogenesis and hypoxia interact through a complex interplay of crosstalk, which is inextricably linked to the TME. Here, we review the TME's positive contribution to angiogenesis from an angiogenesis-centric perspective while considering the objective impact of hypoxic phenotypes and the status and limitations of current angiogenic therapies.

From desert flora to cancer therapy: systematic exploration of multi-pathway mechanisms using network pharmacology and molecular modeling approaches

Ovarian cancer, often labeled a "silent killer," remains one of the most compelling and challenging areas of cancer research. In 2019 alone, a staggering 222,240 new cases of ovarian cancer were reported, with nearly 14,170 lives tragically lost to this relentless disease. The absence of effective diagnostic methods, increased resistance to chemotherapy, and the heterogeneous nature of ovarian cancer collectively contribute to the unfavorable prognosis observed in the majority of cases. Thus, there is a pressing need to explore therapeutic interventions that offer superior efficacy and safety, thereby enhancing the survival prospects for ovarian cancer patients. Recognizing this potential, our research synergizes bioinformatics with a network pharmacology approach to investigate the underlying molecular interactions of Saudi Arabian flora (Onopordum heteracanthum, Acacia ehrenbergiana, Osteospermum vaillantii, Cyperus rotundus, Carissa carandas, Carissa spinarum, and Camellia sinensis) in ovarian cancer treatment. At first, phytoconstituents of indigenous flora and their associated gene targets, particularly those pertinent to ovarian cancer, were obtained from open-access databases. Later, the shared targets of plants and diseases were compared to identify common targets. A protein-protein interaction (PPI) network of predicted targets was then constructed for the identification of key genes having the highest degree of connectivity among networks. Following that, a compound-target protein-pathway network was constructed, which uncovered that, namely, hispidulin, stigmasterol, ascorbic acid, octopamine, cyperene, kaempferol, pungenin, citric acid, d-tartaric acid, beta-sitosterol, (-)-epicatechin gallate, and (+)-catechin demonstrably influence cell proliferation and growth by impacting the AKT1 and VEGFA proteins. Molecular docking, complemented by a 20-ns molecular dynamic (MD) simulation, was used, and the binding affinity of the compound was further validated. Molecular docking, complemented by a 20-ns MD simulation, confirmed the binding affinity of these compounds. Specifically, for AKT1, ascorbic acid showed a docking score of -11.1227 kcal/mol, interacting with residues Ser A:240, Leu A:239, Arg A:243, Arg C:2, and Glu A:341. For VEGFA, hispidulin exhibited a docking score of -17.3714 kcal/mol, interacting with Asn A:158, Val A:190, Gln B:160, Ser A:179, and Ser B:176. To sum up, both a theoretical and empirical framework were established by this study, directing more comprehensive research and laying out a roadmap for the potential utilization of active compounds in the formulation of anti-cancer treatments.

Isorhamnetin: what is the in vitro evidence for its antitumor potential and beyond?

Isorhamnetin (ISO) is a phenolic compound belonging to flavonoid family, showcasing important in vitro pharmacological activities such as antitumor, anti-inflammation, and organ protection. ISO is predominantly extracted from Hippophae rhamnoides L. This plant is well-known in China and abroad because of its "medicinal and food homologous" characteristics. As a noteworthy natural drug candidate, ISO has received considerable attention in recent years owing to its low cost, wide availability, high efficacy, low toxicity, and minimal side effects. To comprehensively elucidate the multiple biological functions of ISO, particularly its antitumor activities and other pharmacological potentials, a literature search was conducted using electronic databases including Web of Science, PubMed, Google Scholar, and Scopus. This review primarily focuses on ISO's ethnopharmacology. By synthesizing the advancements made in existing research, it is found that the general effects of ISO involve a series of in vitro potentials, such as antitumor, protection of cardiovascular and cerebrovascular, anti-inflammation, antioxidant, and more. This review illustrates ISO's antitumor and other pharmacological potentials, providing a theoretical basis for further research and new drug development of ISO.

Nature-Inspired Compounds: Synthesis and Antibacterial Susceptibility Testing of Eugenol Derivatives against H. pylori Strains

The antimicrobial properties of one of the most important secondary metabolites, Eugenol (EU), inspired us to design and synthesize three different series of derivatives enhancing its parent compound's anti-Helicobacter pylori activity. Thus, we prepared semisynthetic derivatives through (A) diazo aryl functionalization, (B) derivatization of the hydroxy group of EU, and (C) elongation of the allyl radical by incorporating a chalcogen atom. The antibacterial evaluation was performed on the reference NCTC 11637 strain and on three drug-resistant clinical isolates and the minimal inhibitory and bactericidal concentrations (MICs and MBCs) highlight the role of chalcogens in enhancing the antimicrobial activity (less than 4 µg/mL for some compounds) of the EU scaffold (32-64 µg/mL).