Evaluation of Silver Nanoparticles Caffeic Acid Complex Compound as New Potential Therapeutic Agent against Cancer Incidence in Mice

Nano-Formulations of Natural Antioxidants for the Treatment of Liver Cancer

Oxidative stress is a key factor in the pathological processes that trigger various chronic liver diseases, and significantly contributes to the development of hepatocarcinogenesis. Natural antioxidants reduce oxidative stress by neutralizing free radicals and play a crucial role in the treatment of free-radical-induced liver diseases. However, their efficacy is often limited by poor bioavailability and metabolic stability. To address these limitations, recent advances have focused on developing nano-drug delivery systems that protect them from degradation and enhance their therapeutic potential. Among the several critical benefits, they showed to be able to improve bioavailability and targeted delivery, thereby reducing off-target effects by specifically directing the antioxidant to the liver tumor site. Moreover, these nanosystems led to sustained release, prolonging the therapeutic effect over time. Some of them also exhibited synergistic effects when combined with other therapeutic agents, allowing for improved overall efficacy. This review aims to discuss recent scientific advances in nano-formulations containing natural antioxidant molecules, highlighting their potential as promising therapeutic approaches for the treatment of liver cancer. The novelty of this review lies in its comprehensive focus on the latest developments in nano-formulations of natural antioxidants for the treatment of liver cancer.

Adjuvant Properties of Caffeic Acid in Cancer Treatment

Caffeic acid (CA) is a polyphenol belonging to the phenylpropanoid family, commonly found in plants and vegetables. It was first identified by Hlasiwetz in 1867 as a breakdown product of caffetannic acid. CA is biosynthesized from the amino acids tyrosine or phenylalanine through specific enzyme-catalyzed reactions. Extensive research since its discovery has revealed various health benefits associated with CA, including its antioxidant, anti-inflammatory, and anticancer properties. These effects are attributed to its ability to modulate several pathways, such as inhibiting NFkB, STAT3, and ERK1/2, thereby reducing inflammatory responses, and activating the Nrf2/ARE pathway to enhance antioxidant cell defenses. The consumption of CA has been linked to a reduced risk of certain cancers, mitigation of chemotherapy and radiotherapy-induced toxicity, and reversal of resistance to first-line chemotherapeutic agents. This suggests that CA could serve as a useful adjunct in cancer treatment. Studies have shown CA to be generally safe, with few adverse effects (such as back pain and headaches) reported. This review collates the latest information from Google Scholar, PubMed, the Phenol-Explorer database, and ClinicalTrials.gov, incorporating a total of 154 articles, to underscore the potential of CA in cancer prevention and overcoming chemoresistance.

Redox-Sensitive Poly(lactic-co-glycolic acid) Nanoparticles of Palbociclib: Development, Ultrasound/Photoacoustic Imaging, and Smart Breast Cancer Therapy

Breast cancer is one of the leading causes of mortality in women globally. The efficacy of breast cancer treatments, notably chemotherapy, is hampered by inadequate localized delivery of anticancer agents to the tumor site, resulting in compromised efficacy and increased systemic toxicity. In this study, we have developed redox-sensitive poly(lactic-co-glycolic acid) (PLGA) nanoparticles for the smart delivery of palbociclib (PLB) to breast cancer. The particle size of formulated PLB@PLGA-NPs (nonredox-sensitive) and RS-PLB@PLGA-NPs (redox-sensitive) NPs were 187.1 ± 1.8 nm and 193.7 ± 1.5 nm, respectively. The zeta potentials of nonredox-sensitive and redox-sensitive NPs were +24.99 ± 2.67 mV and +9.095 ± 1.87 mV, respectively. The developed NPs were characterized for morphological and various physicochemical parameters such as SEM, TEM, XRD, DSC, TGA, XPS, etc. The % entrapment efficiency of PLB@PLGA-NPs and RS-PLB@PLGA-NPs was found to be 85.48 ± 1.29% and 87.72 ± 1.55%, respectively. RS-PLB@PLGA-NPs displayed a rapid drug release at acidic pH and a higher GSH concentration compared to PLB@PLGA-NPs. The cytotoxicity assay in MCF-7 cells suggested that PLB@PLGA-NPs and RS-PLB@PLGA-NPs were 5.24-fold and 14.53-fold higher cytotoxic compared to the free PLB, respectively. Further, the cellular uptake study demonstrated that redox-sensitive NPs had significantly higher cellular uptake compared to nonredox-sensitive NPs and free Coumarin 6 dye. Additionally, AO/EtBr assay and reactive oxygen species analysis confirmed the superior activity of RS-PLB@PLGA-NPs over PLB@PLGA-NPs and free PLB. In vivo anticancer activity in dimethyl-benz(a)anthracene-induced breast cancer rats depicted that RS-PLB@PLGA-NPs was highly effective in reducing the tumor size, hypoxic tumor, and tumor vascularity compared to PLB@PLGA-NPs and free PLB. Further, hemocompatibility study reveals that the developed NPs were nonhemolytic to human blood. Moreover, an in vivo histopathology study confirmed that both nanoparticles were safe and nontoxic to the vital organs.

Cutaneous melanoma and purinergic modulation by phenolic compounds

Cutaneous melanoma is a complex pathology that still has only treatments that lack efficiency and offer many adverse effects. Due to this scenario emerges the need to analyze other possible treatments against this disease, such as the effect of phenolic compounds. These substances have proven antitumor effects, but still have not been fully explored as a form of therapy to combat melanoma. Also, the purinergic receptors, along with its system molecules, take part in the formation of tumors from many pathways, such as the actions of ectoenzymes and receptors activity, especially P2Rs family, and are formed by structures that can be modulated by the phenolic compounds. Therefore, more studies have to be made with the aim of explaining the purinergic system activity in carcinogenesis of cutaneous melanoma and the effects of its modulation by phenolic compound, in order to enable the development of new therapies to combat this aggressive and feared cancer.

Current advances in nanoformulations of therapeutic agents targeting tumor microenvironment to overcome drug resistance

The tumor microenvironment (TME) plays a pivotal role in cancer development and progression. In this line, revealing the precise mechanisms of the TME and associated signaling pathways of tumor resistance could pave the road for cancer prevention and efficient treatment. The use of nanomedicine could be a step forward in overcoming the barriers in tumor-targeted therapy. Novel delivery systems benefit from enhanced permeability and retention effect, decreasing tumor resistance, reducing tumor hypoxia, and targeting tumor-associated factors, including immune cells, endothelial cells, and fibroblasts. Emerging evidence also indicates the engagement of multiple dysregulated mediators in the TME, such as matrix metalloproteinase, vascular endothelial growth factor, cytokines/chemokines, Wnt/β-catenin, Notch, Hedgehog, and related inflammatory and apoptotic pathways. Hence, investigating novel multitargeted agents using a novel delivery system could be a promising strategy for regulating TME and drug resistance. In recent years, small molecules from natural sources have shown favorable anticancer responses by targeting TME components. Nanoformulations of natural compounds are promising therapeutic agents in simultaneously targeting multiple dysregulated factors and mediators of TME, reducing tumor resistance mechanisms, overcoming interstitial fluid pressure and pericyte coverage, and involvement of basement membrane. The novel nanoformulations employ a vascular normalization strategy, stromal/matrix normalization, and stress alleviation mechanisms to exert higher efficacy and lower side effects. Accordingly, the nanoformulations of anticancer monoclonal antibodies and conventional chemotherapeutic agents also improved their efficacy and lessened the pharmacokinetic limitations. Additionally, the coadministration of nanoformulations of natural compounds along with conventional chemotherapeutic agents, monoclonal antibodies, and nanomedicine-based radiotherapy exhibits encouraging results. This critical review evaluates the current body of knowledge in targeting TME components by nanoformulation-based delivery systems of natural small molecules, monoclonal antibodies, conventional chemotherapeutic agents, and combination therapies in both preclinical and clinical settings. Current challenges, pitfalls, limitations, and future perspectives are also discussed.

Therapeutic Implications of Caffeic Acid in Cancer and Neurological Diseases

Caffeic acid (CA) is found abundantly in fruits, vegetables, tea, coffee, oils, and more. CA and its derivatives have been used for many centuries due to their natural healing and medicinal properties. CA possesses various biological and pharmacological activities, including antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. The potential therapeutic effects of CA are mediated via repression and inhibition of transcription and growth factors. CA possesses potential anticancer and neuroprotective effects in human cell cultures and animal models. However, the biomolecular interactions and pathways of CA have been described highlighting the target binding proteins and signaling molecules. The current review focuses on CA's chemical, physical, and pharmacological properties, including antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. We further described CA's characteristics and therapeutic potential and its future directions.