Pretreatment with Liposome-Encapsulated Shrimp Shell Extract Attenuated Neuronal Damage and Death in Aß1-42-Induced Memory Deficits in Rats.

The accumulation of amyloid-beta (Aß) peptides is a crucial factor in the neuronal degeneration of Alzheimer's disease (AD). The current study investigated the underlying neuroprotective mechanisms of shrimp shell extract (SSE) and liposome-encapsulated SSE (SSE/L) against Aß1-42-induced neuronal damage and death in rats. Intracerebroventricular infusion of Aß1-42 effectively induced memory decline, as observed in a reduction of the rat's discriminating ability in the novel object recognition and novel object location tasks. Oral pretreatment with 100 mg/kg of SSE demonstrated no preventive effect on the memory decline induced by Aß1-42 infusion. However, treatment with SSE/L 100 mg/kg BW effectively attenuated memory deficits in both behavioral assessments following two and four weeks after Aß1-42 infusion. Moreover, SSE/L exerted neuroprotective effects by reducing lipid peroxidation and increasing Nrf2/HO-1 expression. There was a significant decrease in Iba1 and GFAP (biomarkers of microglia and astrocyte activity, respectively), as well as a decrease in the levels of NF-κB expression and the inflammatory cytokines TNF-α and IL-6 in the cortical and hippocampal tissues. Treatment with SSE/L also reduced the pro-apoptotic proteins Bax and cleaved caspase-3 while raising the anti-apoptotic protein Bcl2. In addition, the beneficial effects of SSE/L were along with the effects of a positive control commercial astaxanthin (AST). The findings of this study indicated that SSE/L provided neuroprotective effects on Aß1-42-induced AD rats by ameliorating oxidative stress, neuroinflammation and apoptotic cell death. Therefore, SSE/L might be employed to prevent and mitigate Aß accumulation-induced neurotoxicity in AD.

Natural products from Odontonema strictum promote neurite outgrowth in neuronal PC12 cells.

The leaves of Odontonema strictum, a tropical plant used for its antihypertensive properties, are rich in nutrients and biologically active phytochemicals, such as ß-sitosterol, stigmasterol, umuravumbolide, deacetylumuravumbolide, dideacetylboronolide, deacetylboronolide, verbascoside, and isoverbascoside. In addition, its roots are rich in ß-sitosterol, stigmasterol, and the iridoid glycoside ß-O-methyl-unedoside. Ingestion of the roots was reported to have a sedative effect in a dog was previously reported on a dog eating the roots of this plant. In the present study, we report for the first time the cell proliferation- and neurite outgrowth-promoting effects in PC12 neuronal cells of the isolated organic compounds and crude extracts from O. strictum. Pituitary adenylate cyclase-activating peptide (PACAP) and quercetin were used as positive controls. At the concentration of 0.2 µg/mL, ß-sitosterol was more potent than quercetin and displayed the same activity (>45 µm/cell) as PACAP (100 nM). At a low concentration (0.04 µg/mL), verbascoside and isoverbascoside showed the strongest neurite outgrowth-promoting effect (neurite length of 30 to 35 µm/cell). Our results indicate that phytomedicines made from O. strictum may be useful in preventing neurodegenerative diseases.

Synthesis of polymeric nanoparticles by double emulsion and pH-driven: encapsulation of antibiotics and natural products for combating Escherichia coli infections.

The design, development, and obtaining of nanostructured materials, such as polymeric nanoparticles, have garnered interest due to loading therapeutic agents and its broad applicability. Polymeric nanoparticle synthesis employs advanced techniques such as the double emulsion approach and the pH-driven method, allowing the efficient incorporation of active compounds into these matrices. These loading methods ensure compound stability within the polymeric structure and enable control of the release of therapeutic agents. The ability of loaded polymeric nanoparticles to transport and release therapeutic agents on target manner represents a significant advancement in the quest for effective therapeutic solutions. Amid escalating concerns regarding antimicrobial resistance, interventions using polymeric nanostructures stand out for the possibility of carrying antimicrobial agents and enhancing antibacterial action against antibiotic-resistant bacteria, making a new therapeutic approach or complement to conventional treatments. In this sense, the capability of these polymeric nanoparticles to act against Escherichia coli underscores their relevance in controlling bacterial infections. This mini-review provides a comprehensive synthesis of promising techniques for loading therapeutic agents into polymeric nanoparticles highlighting methodologies and their implications, addressing prospects of combating bacterial infections caused by E. coli. KEY POINTS: • The double emulsion method provides control over size and release of bioactives. • The pH-driven method improves the solubility, stability, and release of active. • The methods increase the antibacterial action of those encapsulated in PNPs.

Photopatterned biomolecule immobilization to guide three-dimensional cell fate in natural protein-based hydrogels.

Hydrogel biomaterials derived from natural biopolymers (e.g., fibrin, collagen, decellularized extracellular matrix) are regularly utilized in three-dimensional (3D) cell culture and tissue engineering. In contrast to those based on synthetic polymers, natural materials permit enhanced cytocompatibility, matrix remodeling, and biological integration. Despite these advantages, natural protein-based gels have lagged behind synthetic alternatives in their tunability; methods to selectively modulate the biochemical properties of these networks in a user-defined and heterogeneous fashion that can drive encapsulated cell function have not yet been established. Here, we report a generalizable strategy utilizing a photomediated oxime ligation to covalently decorate naturally derived hydrogels with bioactive proteins including growth factors. This bioorthogonal photofunctionalization is readily amenable to mask-based and laser-scanning lithographic patterning, enabling full four-dimensional (4D) control over protein immobilization within virtually any natural protein-based biomaterial. Such versatility affords exciting opportunities to probe and direct advanced cell fates inaccessible using purely synthetic approaches in response to anisotropic environmental signaling.

Electrospun Nanofibers Encapsulated with Natural Products: A Novel Strategy to Counteract Skin Aging.

The skin is the primary tissue affected by wounds and aging, significantly impacting its protective function. Natural products are widely used in cosmetics, representing a new approach to preventing age-related damage. Nanomedicine combines nanotechnology and traditional treatments to create innovative drugs. The main targets of nanotechnological approaches are wound healing, regeneration, and rejuvenation of skin tissue. The skin barrier is not easily permeable, and the creation of modern nanodevices is a way to improve the passive penetration of substances. In this study, Helichrysum italicum oil (HO) was combined with different types of electrospun nanofibers to study their protective activity on the skin and to evaluate their future application for topical treatments. In the present research, we used biodegradable polymers, including polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), which were characterized by a scanning electron microscope (SEM). All results show a positive trend in cell proliferation and viability of human skin stem cells (SSCs) and BJ fibroblasts pre-treated with combined nanofibers and then exposed to UV stress. Gene expression analysis revealed the activation of a molecular rejuvenation program in SSCs treated with functionalized nanofibers before UV exposure. Understanding the mechanisms involved in skin changes during aging allows for the future application of nanomaterials combined with HO directly to the patients.

Graphene and Natural Products: A Review of Antioxidant Properties in Graphene Oxide Reduction.

This review article addresses the antioxidant properties of different natural products, including ascorbic acid, gallic acid, oxalic acid, L-glutathione (GSH), bacteriorhodopsin, green tea polyphenols, glucose, hydroxycinnamic acid, ethanoic acid, betanin, and L-glutathione, in the reduction of graphene oxide (rGO). rGO can cause damage to cells, including oxidative stress and inflammation, limiting its application in different sectors that use graphene, such as technologies used in medicine and dentistry. The natural substances reviewed have properties that help reduce this damage, neutralizing free radicals and maintaining cellular integrity. This survey demonstrates that the combination of these antioxidant compounds can be an effective strategy to minimize the harmful effects of rGO and promote cellular health.

Natural product protulactone A: Total synthesis from D-galactose, X-ray analysis and biological evaluation.

Synthesis of protulactone A (PLA, 1) and twelve of its analogues have been achieved starting from d-galactose. PLA was isolated in the crystalline state, and its crystal structure was determined utilizing X-ray crystallography, which confirmed the assumed stereochemistry at all stereocenters. All tested compounds displayed antiproliferative activity against a panel of tumour cell lines, and all of them were non-cytotoxic toward the normal cells (MRC-5). Natural product PLA (1) was the most active against the K562 and MCF-7 cell lines (IC50 6.52 and 2.20 µM, respectively). Some of the synthesized derivatives showed very potent cytotoxicity, especially analogues 11, 13 and 15 (IC50 1.08-1.14 µM against MCF-7), and 9 and 14 (IC50 1.29 and 1.64 µM against K562). SAR analysis indicated important structural motifs for antiproliferative activity. Unfortunately, PLA (1), its C-7 epimer (2) and demethylated analogue (3) did not display a significant antimicrobial activity (two Gram-positive and two Gram-negative bacteria and one fungal strain) and they also cannot affect the ability to modulate bacterial communication.

Therapeutic Potential and Nutraceutical Profiling of North Bornean Seaweeds: A Review.

Malaysia has a long coastline surrounded by various islands, including North Borneo, that provide a suitable environment for the growth of diverse species of seaweeds. Some of the important North Bornean seaweed species are Kappaphycus alvarezii, Eucheuma denticulatum, Halymenia durvillaei (Rhodophyta), Caulerpa lentillifera, Caulerpa racemosa (Chlorophyta), Dictyota dichotoma and Sargassum polycystum (Ochrophyta). This review aims to highlight the therapeutic potential of North Bornean seaweeds and their nutraceutical profiling. North Bornean seaweeds have demonstrated anti-inflammatory, antioxidant, antimicrobial, anticancer, cardiovascular protective, neuroprotective, renal protective and hepatic protective potentials. The protective roles of the seaweeds might be due to the presence of a wide variety of nutraceuticals, including phthalic anhydride, 3,4-ethylenedioxythiophene, 2-pentylthiophene, furoic acid (K. alvarezii), eicosapentaenoic acid, palmitoleic acid, fucoxanthin, ß-carotene (E. denticulatum), eucalyptol, oleic acid, dodecanal, pentadecane (H. durvillaei), canthaxanthin, oleic acid, pentadecanoic acid, eicosane (C. lentillifera), pseudoephedrine, palmitic acid, monocaprin (C. racemosa), dictyohydroperoxide, squalene, fucosterol, saringosterol (D. dichotoma), and lutein, neophytadiene, cholest-4-en-3-one and cis-vaccenic acid (S. polycystum). Extensive studies on the seaweed isolates are highly recommended to understand their bioactivity and mechanisms of action, while highlighting their commercialization potential.

Biomaterials and Bioactive Natural Products from Marine Invertebrates: From Basic Research to Innovative Applications.

Aquatic invertebrates are a major source of biomaterials and bioactive natural products that can find applications as pharmaceutics, nutraceutics, cosmetics, antibiotics, antifouling products and biomaterials. Symbiotic microorganisms are often the real producers of many secondary metabolites initially isolated from marine invertebrates; however, a certain number of them are actually synthesized by the macro-organisms. In this review, we analysed the literature of the years 2010-2019 on natural products (bioactive molecules and biomaterials) from the main phyla of marine invertebrates explored so far, including sponges, cnidarians, molluscs, echinoderms and ascidians, and present relevant examples of natural products of interest to public and private stakeholders. We also describe omics tools that have been more relevant in identifying and understanding mechanisms and processes underlying the biosynthesis of secondary metabolites in marine invertebrates. Since there is increasing attention on finding new solutions for a sustainable large-scale supply of bioactive compounds, we propose that a possible improvement in the biodiscovery pipeline might also come from the study and utilization of aquatic invertebrate stem cells.

Marine-Inspired Drugs and Biomaterials in the Perspective of Pancreatic Cancer Therapies.

Despite its low prevalence, pancreatic cancer (PC) is one of the deadliest, typically characterised as silent in early stages and with a dramatically poor prognosis when in its advanced stages, commonly associated with a high degree of metastasis. Many efforts have been made in pursuing innovative therapeutical approaches, from the search for new cytotoxic drugs and other bioactive compounds, to the development of more targeted approaches, including improved drug delivery devices. Marine biotechnology has been contributing to this quest by providing new chemical leads and materials originating from different organisms. In this review, marine biodiscovery for PC is addressed, particularly regarding marine invertebrates (namely sponges, molluscs, and bryozoans), seaweeds, fungi, and bacteria. In addition, the development of biomaterials based on marine-originating compounds, particularly chitosan, fucoidan, and alginate, for the production of advanced cancer therapies, is also discussed. The key role that drug delivery can play in new cancer treatments is highlighted, as therapeutical outcomes need to be improved to give further hope to patients.

Enhanced Antimicrobial Activity of Biocompatible Bacterial Cellulose Films via Dual Synergistic Action of Curcumin and Triangular Silver Nanoplates.

Curcumin and triangular silver nanoplates (TSNP)-incorporated bacterial cellulose (BC) films present an ideal antimicrobial material for biomedical applications as they afford a complete set of requirements, including a broad range of long-lasting potency and superior efficacy antimicrobial activity, combined with low toxicity. Here, BC was produced by Komagataeibacter medellinensis ID13488 strain in the presence of curcumin in the production medium (2 and 10%). TSNP were incorporated in the produced BC/curcumin films using ex situ method (21.34 ppm) and the antimicrobial activity was evaluated against Escherichia coli ATCC95922 and Staphylococcus aureus ATCC25923 bacterial strains. Biological activity of these natural products was assessed in cytotoxicity assay against lung fibroblasts and in vivo using Caenorhabditis elegans and Danio rerio as model organisms. Derived films have shown excellent antimicrobial performance with growth inhibition up to 67% for E. coli and 95% for S. aureus. In a highly positive synergistic interaction, BC films with 10% curcumin and incorporated TSNP have shown reduced toxicity with 80% MRC5 cells survival rate. It was shown that only 100% concentrations of film extracts induce low toxicity effect on model organisms' development. The combined and synergistic advanced anti-infective functionalities of the curcumin and TSNP incorporated in BC have a high potential for development for application within the clinical setting.

Natural Product-Derived Phosphonic Acids as Corrosion Inhibitors for Iron and Steel.

Organic acids, typically derived from an oil-based value chain, are frequently used as corrosion inhibitors in industrial metal working fluids. The criteria for selection of these corrosion inhibitors have changed in the last decades, and are today not only performance-driven, but influenced by ecological considerations, toxicity and regulatory standards. We present scalable semisynthetic approaches to organic corrosion inhibitors based on phosphonic acids from renewable resources. They have been evaluated by chip filter assay, potentiodynamic polarization measurements, electrochemical impedance measurements and gravimetry for corrosion protection of iron and steel in an aqueous environment at slightly alkaline pH. The efficacy of several phosphonic acids tested was found to be strongly dependent on structural features influencing molecular self-assembly of protective layers, and the solubility of salts formed with di- and trivalent cations from the media or formed during corrosion. A carboxyphosphonic acid (derived from castor oil) was found to have remarkable anticorrosive effects in all media tested. We attribute the anticorrosion properties of this carboxyphosphonic acid to the formation of particularly stable protective layers on the metal surface. It might thus serve as a commercially attractive substitute for current acidic corrosion inhibitors, derived from renewable resources.

Host-Guest Inclusion Complexes of Natural Products and Nanosystems: Applications in the Development of Repellents.

Repellents are compounds that prevent direct contact between the hosts and the arthropods that are vectors of diseases. Several studies have described the repellent activities of natural compounds obtained from essential oils. In addition, these chemical constituents have been pointed out as alternatives to conventional synthetic repellents due to their interesting residual protection and low toxicity to the environment. However, these compounds have been reported with short shelf life, in part, due to their volatile nature. Nanoencapsulation provides protection, stability, conservation, and controlled release for several compounds. Here, we review the most commonly used polymeric/lipid nanosystems applied in the encapsulation of small organic molecules obtained from essential oils that possess repellent activity, and we also explore the theoretical aspects related to the intermolecular interactions, thermal stability, and controlled release of the nanoencapsulated bioactive compounds.

Natural Products in Mitigation of Bisphenol A Toxicity: Future Therapeutic Use.

Bisphenol A (BPA) is a ubiquitous environmental toxin with deleterious endocrine-disrupting effects. It is widely used in producing epoxy resins, polycarbonate plastics, and polyvinyl chloride plastics. Human beings are regularly exposed to BPA through inhalation, ingestion, and topical absorption routes. The prevalence of BPA exposure has considerably increased over the past decades. Previous research studies have found a plethora of evidence of BPA's harmful effects. Interestingly, even at a lower concentration, this industrial product was found to be harmful at cellular and tissue levels, affecting various body functions. A noble and possible treatment could be made plausible by using natural products (NPs). In this review, we highlight existing experimental evidence of NPs against BPA exposure-induced adverse effects, which involve the body's reproductive, neurological, hepatic, renal, cardiovascular, and endocrine systems. The review also focuses on the targeted signaling pathways of NPs involved in BPA-induced toxicity. Although potential molecular mechanisms underlying BPA-induced toxicity have been investigated, there is currently no specific targeted treatment for BPA-induced toxicity. Hence, natural products could be considered for future therapeutic use against adverse and harmful effects of BPA exposure.

Berberine as a promising natural compound for the treatment of periodontal disease: A focus on anti-inflammatory properties.

Accumulating evidence during the last two decades has addressed the potential anti-inflammatory properties of berberine (BBR), a bioactive alkaloid compound isolated from Coptidis rhizoma, in controlling or treating several inflammatory diseases. Periodontitis is one of the most common chronic and serious inflammatory diseases, in which uncontrolled and unabated host immune responses against periodontopathic pathogens play critical and crucial roles in the disease pathogenesis. Hence, regulating inflammatory responses in periodontitis has a valuable approach and holds promise in treating periodontitis. For the first time, this paper reviews the evidence from in vitro and in vivo experimental models to explore the anti-inflammatory effects of BBR in periodontitis and exhibits that BBR has the high potency to exert anti-inflammatory effects by reducing expression and secretion of pro-inflammatory mediators including TNF-α, IL-1ß, IL-17, RANKL, MMP-2, MMP-9 and MCP-1. The BBR-mediated anti-inflammatory actions could translate into the inhibition of the periodontal tissues and alveolar bone destruction and the control of the disease in vivo. As the second aim of this paper, we also paid attention to the therapeutic potential of BBR in treating human diseases regarding its anti-inflammatory properties.

The inhibition of enterovirus 71 induced apoptosis by Durvillaea antarctica through P53 and STAT1 signaling pathway.

The infection of enterovirus 71 (EV71) resulted in hand, foot, and mouth disease and may lead to severe nervous system damage and even fatalities. There are no effective drugs to treat the EV71 virus and it is crucial to find novel drugs against it. Polysaccharide isolated from Durvillaea antarctica green algae has an antiviral effect. In this study, D. antarctica polysaccharide (DAPP) inhibited the infection of EV71 was demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), reverse transcription polymerase chain reaction, flow cytometry, and western blot. MTT assay showed that DAPP had no toxicity on Vero cells at the concentration 250 µg/ml. Furthermore, DAPP significantly reduced the RNA level of EV71 in a dose-dependent manner. Moreover, DAPP inhibited the Vero cells apoptosis induced by EV71 via the P53 signaling pathway. Meanwhile, the expression of signal transducer and activator of transcription 1 and mammalian target of rapamycin were increased and the proinflammatory cytokines were significantly inhibited by DAPP. Taken together, these results suggested that DAPP could be a potential pharmaceutical against the infection of EV71 virus.

Development of films from natural sources for infections during wound healing.

The skin is the largest organ in the human body, and due to its barrier function, it is susceptible to multiple injuries. The appearance of infections during the wound healing process is a complication that represents a formidable hospital challenge. The presence of opportunistic bacteria with sophisticated resistance mechanisms is difficult to eradicate and compromises patients' lives. Therefore, the search for new efficacious treatments from natural sources that prevent and counteract infections, in addition to promoting the healing process, has increased in recent years. In this respect, films with the capability to protect wounds and release drugs are the presentation that predominates commercially in the hospital environment. Those films can offer several mechanical advantages such as physical protection to prevent opportunistic bacteria's entry, regulation of gas exchange, and capture of exudate through a swelling process. Wound dressings are generally curative materials easily adaptable to different anatomical regions, with high strength and elasticity, and some are even bioabsorbable. Additionally, the components of the films can actively participate in promoting the healing process. Even more, the film can be made up of carriers with other active participants to prevent and eradicate infections. Therefore, the extensive versatility, practicality, and usefulness of films from natural sources to address infectious processes during wound healing are relevant and recurrent themes. This work presents an analysis of the state-of-the-art of films with natural products focused on preventing and eradicating infections in wound healing.

Natural Polymers for the Maintenance of Oral Health: Review of Recent Advances and Perspectives.

The success of modern dental treatment is strongly dependent on the materials used both temporarily and permanently. Among all dental materials, polymers are a very important class with a wide spectrum of applications. This review aims to provide a state-of-the-art overview of the recent advances in the field of natural polymers used to maintain or restore oral health. It focuses on the properties of the most common proteins and polysaccharides of natural origin in terms of meeting the specific biological requirements in the increasingly demanding field of modern dentistry. The use of naturally derived polymers in different dental specialties for preventive and therapeutic purposes has been discussed. The major fields of application cover caries and the management of periodontal diseases, the fabrication of membranes and scaffolds for the regeneration of dental structures, the manufacturing of oral appliances and dentures as well as providing systems for oral drug delivery. This paper also includes a comparative characteristic of natural and synthetic dental polymers. Finally, the current review highlights new perspectives, possible future advancements, as well as challenges that may be encountered by researchers in the field of dental applications of polymers of natural origin.

Chemotactic and Angiogenic Potential of Mineralized Collagen Scaffolds Functionalized with Naturally Occurring Bioactive Factor Mixtures to Stimulate Bone Regeneration.

To develop cost-effective and efficient bone substitutes for improved regeneration of bone defects, heparin-modified mineralized collagen scaffolds were functionalized with concentrated, naturally occurring bioactive factor mixtures derived from adipose tissue, platelet-rich plasma and conditioned medium from a hypoxia-treated human bone marrow-derived mesenchymal stem cell line. Besides the analysis of the release kinetics of functionalized scaffolds, the bioactivity of the released bioactive factors was tested with regard to chemotaxis and angiogenic tube formation. Additionally, functionalized scaffolds were seeded with human bone marrow-derived mesenchymal stromal cells (hBM-MSC) and their osteogenic and angiogenic potential was investigated. The release of bioactive factors from the scaffolds was highest within the first 3 days. Bioactivity of the released factors could be confirmed for all bioactive factor mixtures by successful chemoattraction of hBM-MSC in a transwell assay as well as by the formation of prevascular structures in a 2D co-culture system of hBM-MSC and human umbilical vein endothelial cells. The cells seeded directly onto the functionalized scaffolds were able to express osteogenic markers and form tubular networks. In conclusion, heparin-modified mineralized collagen scaffolds could be successfully functionalized with naturally occurring bioactive factor mixtures promoting cell migration and vascularization.

Process Development for the Detoxification of Fermentation Inhibitors from Acid Pretreated Microalgae Hydrolysate.

The aim of this study was to remove 5-hydroxymethyl furfural (5-HMF) and furfural, known as fermentation inhibitors, in acid pretreated hydrolysates (APH) obtained from Scenedesmus obliquus using activated carbon. Microwave-assisted pretreatment was used to produce APH containing glucose, xylose, and fermentation inhibitors (5-HMF, furfural). The response surface methodology was applied to optimize key detoxification variables such as temperature (16.5-58.5 °C), time (0.5-5.5 h), and solid-liquid (S-L) ratio of activated carbon (0.6-7.4 w/v%). Three variables showed significant effects on the removal of fermentation inhibitors. The optimum detoxification conditions with the maximum removal of fermentation inhibitors and the minimum loss of sugars (glucose and xylose) were as follows: temperature of 36.6 °C, extraction time of 3.86 h, and S-L ratio of 3.3 w/v%. Under these conditions, removal of 5-HMF, furfural, and sugars were 71.6, 83.1, and 2.44%, respectively, which agreed closely with the predicted values. When the APH and detoxified APH were used for ethanol fermentation by S. cerevisiae, the ethanol produced was 38.5% and 84.5% of the theoretical yields, respectively, which confirmed that detoxification using activated carbon was effective in removing fermentation inhibitors and increasing fermentation yield without significant removal of fermentable sugars.