Search Results (46)

Tetracycline antibiotics are widely used, but their resistance to degradation and persistence in the environment pose a potential risk of inducing antibiotic resistance, creating significant threats to both the environment and human health. This study established a laccase–mediator system (LMS) using natural green tea polyphenols (GTPs) as mediators for efficient tetracycline degradation. Through analyzing the main GTP components and optimizing the reaction conditions, the degradation efficiency of the system was evaluated. The experimental results indicated that, among the various tea polyphenol components, epicatechin gallate (ECG) contributed the most significantly to the degradation efficiency. Under optimized conditions, the Lac-ECG system degraded over 98% of tetracycline within 3–4 min. Further optimization of the Lac-GTP system allowed us to identify the following optimal conditions: a GTP concentration of 1.0 mmol/L, laccase concentration of 1.0 mg/mL, pH of 6.0, and temperature of 25 °C. Under these conditions, a degradation rate of 95.07% was attained within 5 min, outperforming a system using the synthetic mediator ABTS. Additionally, metal ions such as Ca²⁺, Mg²⁺, Cu²⁺, Fe³⁺, Fe²⁺, and Ni²⁺ were found to enhance the degradation process, while Mn²⁺ and Hg²⁺ exhibited inhibitory effects. Antibacterial activity tests revealed that the degradation products completely lost their antimicrobial activity, demonstrating effective detoxification of tetracycline. In conclusion, the tea polyphenol-based laccase–mediator system developed in this study exhibits high efficiency, cost-effectiveness, and environmental friendliness, offering a promising strategy for the remediation of tetracycline-contaminated environments. Full article

Parkinson’s disease (PD) is a neurodegenerative condition in which degeneration mostly occurs in the dopamine (DA)-producing neurons within the substantia nigra in the midbrain. As a result, individuals with this condition suffer from progressively worsening motor impairment because of the resulting DA deficiency, along with an array of other symptoms that, over time, force them into a completely debilitating state. As an age-related disease, PD has only risen in prevalence over the years; thus, an emphasis has recently been placed on discovering a new treatment for this condition that is capable of attenuating its progression. The gut microbiota has become an area of intrigue among PD studies, as research into this topic has shown that imbalances in the gut microbiota (colloquially known as gut dysbiosis) seemingly promote the primary etiologic factors that have been found to be associated with PD and its pathologic progression. With this knowledge, research into PD treatment has begun to expand beyond synthetic pharmaceutical compounds, as a growing emphasis has been placed on studying plant-derived polyphenolic compounds, namely flavonoids, as a new potential therapeutic approach. Due to their capacity to promote a state of homeostasis in the gut microbiota and their long-standing history as powerful medicinal agents, flavonoids have begun to be looked at as promising therapeutic agents capable of attenuating several of the pathologic states seen amidst PD through indirect and direct means. This review article focuses on three flavonoids, specifically epigallocatechin-3-gallate, quercetin, and kaempferol, discussing the mechanisms through which these powerful flavonoids can potentially prevent gut dysbiosis, neuroinflammation, and other molecular mechanisms involved in the pathogenesis and progression of PD, while also exploring their real-world application and how issues of bioavailability and potential drug interactions can be circumvented or exploited. Full article

Triple-negative breast cancer (TNBC) accounts for 15% of all breast cancers and is highly aggressive. Despite an initial positive response to chemotherapy, most patients experience rapid disease progression leading to relapse and metastasis. This is attributed to the presence of breast cancer stem cells (BCSCs) within the tumor, which are characterized by self-renewal, pluripotency, and resistance mechanisms. Targeting BCSCs has become critical as conventional therapies fail to eradicate them due to a lack of specific targets. Curcumin, a polyphenol derived from turmeric (Curcuma longa), exhibits anticancer effects against breast cancer cells and BCSCs. The use of curcumin derivatives has been suggested as an approach to overcome the bioavailability and solubility problems of curcumin in humans, thereby increasing its anticancer effects. The aim of this study was to evaluate the cellular and molecular effects of six synthetic compounds derived from the natural polyphenol epigallocatechin gallate (EGCG) (TL1, TL2) and curcumin derivatives (TL3, TL4, TL5, and TL6) on a TNBC mesenchymal stem-like cell line. The activity of the compounds against BCSCs was also determined by a mammosphere inhibition assay and studying different BCSC markers by Western blotting. Finally, a drug combination assay was performed with the most promising compounds to evaluate their potential synergistic effects with the chemotherapeutic agents doxorubicin, cisplatin, and paclitaxel. The results showed that compounds exhibited specific cytotoxicity against the TNBC cell line and BCSCs. Interestingly, the combination of the curcumin derivative TL3 with doxorubicin and cisplatin displayed a synergistic effect in TNBC cells. Full article

Fragment-based drug discovery (FBDD) focuses on small compounds, known as fragments, typically with a molecular weight of less than 300 Da. This study highlights the benefits of employing a pure natural product library for FBDD, contrasting with the predominant use of synthetic libraries. Practical methods for rapidly constructing such libraries from crude extracts were demonstrated across various plant and microbial samples. Twenty-nine (29) natural product fragments, including a new compound (20), were identified. Antimicrobial activities were assessed for a subset of the isolated compounds, revealing potent fragments (MICs 4–8 μg/mL) against Mycobacterium bovis bacille Calmette-Guérin (BCG), Staphylococcus aureus (SA), and methicillin-resistant S. aureus (MRSA). Furthermore, a native mass spectrometry technique was introduced to rapidly identify non-competitive fragments against malarial proteins. As a result, two pairs of non-competitive fragments, lepiotin C (31) and 7-amino deacetoxy cephalosporanic acid (32) binding to dynein light chain 1, methyl gallate (33) and β-santanin (34) binding to dUTPase, were identified, serving as promising starting points for developing potent malarial protein inhibitors. Full article

In recent years, due to their distinctive and adaptable therapeutic effects, many natural bioactive compounds have been commonly used to treat diseases. Their limited solubility, low bioavailability, inadequate gastrointestinal tract stability, high metabolic rate, and shorter duration of action limited their pharmaceutical applications. However, those can be improved using nanotechnology to create various drug delivery systems, including lipid-based nanoparticles, to adjust the compounds’ physicochemical properties and pharmacokinetic profile. Because of the enormous technical advancements made in the fundamental sciences and the physical and chemical manipulation of individual atoms and molecules, the subject of nanotechnology has experienced revolutionary growth. By fabricating certain functionalized particles, nanotechnology opens an innovative horizon in research and development for overcoming restrictions, including traditional medication administration systems. Nanotechnology-driven bioactive compounds are certain to have a high impact and clinical value for current and future uses. Lipid-based nanotechnologies were shown to deliver a range of naturally occurring bioactive compounds with decent entrapment potential and stability, a successfully controlled release, increased bioavailability, and intriguing therapeutic activity. This review outlines bioactive compounds such as paclitaxel, curcumin, rhodomyrtone, quercetin, kaempferol, resveratrol, epigallocatechin-3-gallate, silymarin, and oridonin, fortified within either a natural or synthetic lipid-based drug delivery system based on nanotechnology and their evaluation and clinical considerations. Full article

Antioxidants, usually administered orally through the systemic route, are known to counteract the harmful effects of oxidative stress on retinal cells. The formulation of these antioxidants as eye drops might offer a new option in the treatment of oxidative retinopathies. In this review, we will focus on the use of some of the most potent antioxidants in treating retinal neuropathies. Melatonin, known for its neuroprotective qualities, may mitigate oxidative damage in the retina. N-acetyl-cysteine (NAC), a precursor to glutathione, enhances the endogenous antioxidant defense system, potentially reducing retinal oxidative stress. Idebenone, a synthetic analogue of coenzyme Q10, and edaravone, a free radical scavenger, contribute to cellular protection against oxidative injury. Epigallocatechin-3-gallate (EGCG), a polyphenol found in green tea, possesses anti-inflammatory and antioxidant effects that could be beneficial in cases of retinopathy. Formulating these antioxidants as eye drops presents a localized and targeted delivery method, ensuring effective concentrations reach the retina. This approach might minimize systemic side effects and enhance therapeutic efficacy. In this paper, we also introduce a relatively new strategy: the alkylation of two antioxidants, namely, edaravone and EGCG, to improve their insertion into the lipid bilayer of liposomes or even directly into cellular membranes, facilitating their crossing of epithelial barriers and targeting the posterior segment of the eye. The synergistic action of these antioxidants may offer a multifaceted defense against oxidative damage, holding potential for the treatment and management of oxidative retinopathies. Further research and clinical trials will be necessary to validate the safety and efficacy of these formulations, but the prospect of antioxidant-based eye drops represents a promising avenue for future ocular therapies. Full article

Voltammetric sensors based on CeO₂, SnO_2, CeO₂·Fe₂O₃ nanoparticles (NPs) and MnO₂ nanorods (NRs) were developed for the quantification of various organic substances. Surfactant media were applied as dispersive agents for metal oxide nanomaterials, providing a high stability of the dispersions after sonication and a decrease in the NPs’ size, as well as the preconcentration of the target analytes at the sensor surface due to the hydrophobic interactions between the surfactant and the analyte molecules. Natural phenolics (quercetin, rutin, gallic acid, taxifolin, eugenol, vanillin, and hesperidin), propyl gallate, α-lipoic acid, and synthetic food colorants (tartrazine, brilliant blue FCF, and sudan I) were studied as analytes. The effect of the nature and concentration of the surfactant on the target analyte response was evaluated. Cationic surfactants (cetylpyridinium (CPB) or cetyltriphenylphosphonium bromides (CTPPB)) showed the best effect for the majority of the analytes. Wide linear dynamic ranges and low detection limits were obtained and were improved vs. reported to date. The simultaneous quantification of tartrazine and brilliant blue FCF was achieved with a high selectivity. The practical applicability of the sensors was shown on the real samples and was validated by comparison to independent methods. Full article

Radiotherapy is an important cancer treatment. However, in addition to killing tumor cells, radiotherapy causes damage to the surrounding cells and is toxic to normal tissues. Therefore, an effective radioprotective agent that prevents the deleterious effects of ionizing radiation is required. Numerous synthetic substances have been shown to have clear radioprotective effects. However, most of these have not been translated for use in clinical applications due to their high toxicity and side effects. Many medicinal plants have been shown to exhibit various biological activities, including antioxidant, anti-inflammatory, and anticancer activities. In recent years, new agents obtained from natural products have been investigated by radioprotection researchers, due to their abundance of sources, high efficiency, and low toxicity. In this review, we summarize the mechanisms underlying the radioprotective effects of natural products, including ROS scavenging, promotion of DNA damage repair, anti-inflammatory effects, and the inhibition of cell death signaling pathways. In addition, we systematically review natural products with radioprotective properties, including polyphenols, polysaccharides, alkaloids, and saponins. Specifically, we discuss the polyphenols apigenin, genistein, epigallocatechin gallate, quercetin, resveratrol, and curcumin; the polysaccharides astragalus, schisandra, and Hohenbuehelia serotina; the saponins ginsenosides and acanthopanax senticosus; and the alkaloids matrine, ligustrazine, and β-carboline. However, further optimization through structural modification, improved extraction and purification methods, and clinical trials are needed before clinical translation. With a deeper understanding of the radioprotective mechanisms involved and the development of high-throughput screening methods, natural products could become promising novel radioprotective agents. Full article

High mortality rates in ovarian cancer have been linked to recurrence, metastasis, and chemoresistant disease, which are known to involve not only genetic changes but also epigenetic aberrations. In ovarian cancer, adipose-derived stem cells from the omentum (O-ASCs) play a crucial role in supporting the tumor and its tumorigenic microenvironment, further propagating epigenetic abnormalities and dissemination of the disease. Epigallocatechin gallate (EGCG), a DNA methyltransferase inhibitor derived from green tea, and Indole-3-carbinol (I3C), a histone deacetylase inhibitor from cruciferous vegetables, carry promising effects in reprograming aberrant epigenetic modifications in cancer. Therefore, we demonstrate the action of these diet-derived compounds in suppressing the growth of 3D ovarian cancer spheroids or organoids as well as post-treatment cancer recovery through proliferation, migration, invasion, and colony formation assays when compared to the synthetic epigenetic compound Panobinostat with or without standard chemotherapy. Finally, given the regulatory role of the secretome in growth, metastasis, chemoresistance, and relapse of disease, we demonstrate that natural epigenetic compounds can regulate the secretion of protumorigenic growth factors, cytokines, extracellular matrix components, and immunoregulatory markers in human ovarian cancer specimens. While further studies are needed, our results suggest that these treatments could be considered in the future as adjuncts to standard chemotherapy, improving efficiency and patient outcomes. Full article

Zika virus (ZIKV) is an arbovirus whose infection in humans can lead to severe outcomes. This article reviews studies reporting the anti-ZIKV activity of natural products (NPs) and derivatives published from 1997 to 2022, which were carried out with NPs obtained from plants (82.4%) or semisynthetic/synthetic derivatives, fungi (3.1%), bacteria (7.6%), animals (1.2%) and marine organisms (1.9%) along with miscellaneous compounds (3.8%). Classes of NPs reported to present anti-ZIKV activity include polyphenols, triterpenes, alkaloids, and steroids, among others. The highest values of the selectivity index, the ratio between cytotoxicity and antiviral activity (SI = CC₅₀/EC₅₀), were reported for epigallocatechin gallate (SI ≥ 25,000) and anisomycin (SI ≥ 11,900) obtained from Streptomyces bacteria, dolastane (SI = 1246) isolated from the marine seaweed Canistrocarpus cervicorni, and the flavonol myricetin (SI ≥ 862). NPs mostly act at the stages of viral adsorption and internalization in addition to presenting virucidal effect. The data demonstrate the potential of NPs for developing new anti-ZIKV agents and highlight the lack of studies addressing their molecular mechanisms of action and pre-clinical studies of efficacy and safety in animal models. To the best of our knowledge, none of the active compounds has been submitted to clinical studies. Full article

The liver is a vital organ that plays a crucial role in the physiological operation of the human body. The liver controls the body’s detoxification processes as well as the storage and breakdown of red blood cells, plasma protein and hormone production, and red blood cell destruction; therefore, it is vulnerable to their harmful effects, making it more prone to illness. The most frequent complications of chronic liver conditions include cirrhosis, fatty liver, liver fibrosis, hepatitis, and illnesses brought on by alcohol and drugs. Hepatic fibrosis involves the activation of hepatic stellate cells to cause persistent liver damage through the accumulation of cytosolic matrix proteins. The purpose of this review is to educate a concise discussion of the epidemiology of chronic liver disease, the pathogenesis and pathophysiology of liver fibrosis, the symptoms of liver fibrosis progression and regression, the clinical evaluation of liver fibrosis and the research into nanotechnology-based synthetic and herbal treatments for the liver fibrosis is summarized in this article. The herbal remedies summarized in this review article include epigallocathechin-3-gallate, silymarin, oxymatrine, curcumin, tetrandrine, glycyrrhetinic acid, salvianolic acid, plumbagin, Scutellaria baicalnsis Georgi, astragalosides, hawthorn extract, and andrographolides. Full article

The COVID-19 pandemic caused by SARS-CoV-2 has majorly impacted public health and economies worldwide. Although several effective vaccines and drugs are now used to prevent and treat COVID-19, natural products, especially flavonoids, showed great therapeutic potential early in the pandemic and thus attracted particular attention. Quercetin, baicalein, baicalin, EGCG (epigallocatechin gallate), and luteolin are among the most studied flavonoids in this field. Flavonoids can directly or indirectly exert antiviral activities, such as the inhibition of virus invasion and the replication and inhibition of viral proteases. In addition, flavonoids can modulate the levels of interferon and proinflammatory factors. We have reviewed the previously reported relevant literature researching the pharmacological anti-SARS-CoV-2 activity of flavonoids where structures, classifications, synthetic pathways, and pharmacological effects are summarized. There is no doubt that flavonoids have great potential in the treatment of COVID-19. However, most of the current research is still in the theoretical stage. More studies are recommended to evaluate the efficacy and safety of flavonoids against SARS-CoV-2. Full article

Scientific interest has currently focused on natural products as a feasible approach for new food additives to replace synthetic preservatives. Thereby, the objective of this work was to optimize the polyphenol extraction from native Amazonian plant species Dalbergia monetaria L.f. and Croton cajucara Benth., and they were determined by the total content of these compounds. Accordingly, the hydroalcoholic extract’s phytocomposition was analyzed by ultra-high-performance liquid chromatography–diode array detector (UPLC-DAD) and various assays to determine the antioxidant capacity (e.g., 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, ferric reduction power, peroxidation inhibition). In addition, response surface methodology applying a central composite design was used to optimize the antioxidant compound extraction conditions. Extract phytochemical profiles identified polyphenols such as (-)-epigallocatechin gallate, rutin, and hyperoside in both species. Furthermore, D. monetaria and C. cajucara extracts displayed significant antioxidant capacity, exhibiting similar values compared to the standard synthetic antioxidant butylated hydroxytoluene. Nevertheless, C. cajucara showed more antioxidant efficiency compared to D. monetaria. These results were consistent with the distribution matrix obtained by a Central Composite Design since the C. cajucara extracts exhibited the best response to the adopted optimization model. Therefore, data are promising for obtaining potential options for natural additives for the food industry. Full article

The main aim of this review is to assess the potential use of natural cross-linking agents, such as genipin, citric acid, tannic acid, epigallocatechin gallate, and vanillin in preparing chemically cross-linked hydrogels for the biomedical, pharmaceutical, and cosmetic industries. Chemical cross-linking is one of the most important methods that is commonly used to form mechanically strong hydrogels based on biopolymers, such as alginates, chitosan, hyaluronic acid, collagen, gelatin, and fibroin. Moreover, the properties of natural cross-linking agents and their advantages and disadvantages are compared relative to their commonly known synthetic cross-linking counterparts. Nowadays, advanced technologies can facilitate the acquisition of high-purity biomaterials from unreacted components with no additional purification steps. However, while planning and designing a chemical process, energy and water consumption should be limited in order to reduce the risks associated with global warming. However, many synthetic cross-linking agents, such as N,N′-methylenebisacrylamide, ethylene glycol dimethacrylate, poly (ethylene glycol) diacrylates, epichlorohydrin, and glutaraldehyde, are harmful to both humans and the environment. One solution to this problem could be the use of bio-cross-linking agents obtained from natural resources, which would eliminate their toxic effects and ensure the safety for humans and the environment. Full article

Cancer is one of the deadliest non communicable diseases. Numerous anticancer medications have been developed to target the molecular pathways driving cancer. However, there has been no discernible increase in the overall survival rate in cancer patients. Therefore, innovative chemo-preventive techniques and agents are required to supplement standard cancer treatments and boost their efficacy. Fruits and vegetables should be tapped into as a source of compounds that can serve as cancer therapy. Phytochemicals play an important role as sources of new medication in cancer treatment. Some synthetic and natural chemicals are effective for cancer chemoprevention, i.e., the use of exogenous medicine to inhibit or impede tumor development. They help regulate molecular pathways linked to the development and spread of cancer. They can enhance antioxidant status, inactivating carcinogens, suppressing proliferation, inducing cell cycle arrest and death, and regulating the immune system. While focusing on four main categories of plant-based anticancer agents, i.e., epipodophyllotoxin, camptothecin derivatives, taxane diterpenoids, and vinca alkaloids and their mode of action, we review the anticancer effects of phytochemicals, like quercetin, curcumin, piperine, epigallocatechin gallate (EGCG), and gingerol. We examine the different signaling pathways associated with cancer and how inflammation as a key mechanism is linked to cancer growth. Full article