Bioactive peptides and depsipeptides with anticancer potential: sources from marine animals

Ensemble learning based on bi-directional gated recurrent unit and convolutional neural network with word embedding module for bioactive peptide prediction

Bioactive peptides, as small protein fragments, are essential mediators of diverse physiological activities, such as antimicrobial, anti-inflammatory, anticancer, antioxidant, and immunomodulatory functions. Despite their substantial potential in pharmaceuticals and the food industry, conventional methods for peptide classification and activity prediction are limited by high costs, time-intensive procedures, and extensive data processing requirements. Here, we present BioPepPred-DLEmb, a novel computational model integrating Convolutional Neural Networks (CNNs) and Bidirectional Gated Recurrent Units (BiGRUs), augmented with natural language processing to encode amino acids into information-dense vectors. Evaluated across nine bioactive peptide datasets, BioPepPred-DLEmb demonstrates superior predictive accuracy (0.909) and sensitivity (0.911) compared to traditional methods. Through UMAP visualization and Kplogo analysis, the model effectively differentiates peptide activity states and identifies key biomarkers. The predicted antimicrobial peptides (Pred-AMPs) exhibit potent efficacy in vitro, achieving low micromolar inhibitory concentrations (2-16 μmol/L) against pathogens such as Escherichia coli and Acinetobacter baumannii. These findings establish a robust foundation for bioactive peptide development, with implications for advancements in precision medicine, personalized therapies, and functional food innovations.

Sika Deer antler protein antagonizes the inflammatory response and oxidative damage induced by jellyfish venom

The investigation into specific treatments for jellyfish stings has consistently presented a significant medical challenge. Sika Deer antler protein (DAP), a valuable component of traditional Chinese medicine (TCM) known for its various pharmacological properties, has been widely utilized for the prevention and treatment of numerous diseases. In this study, proteome analysis and biological activity assays of DAP identified 94 distinct protein components and demonstrated its capability to scavenge free radicals. Moreover, administration of 50 mg/kg DAP notably enhanced survival rates in mice, mitigated increases in hematological indicators and inflammatory markers (IL-6, IL-1β, and TNF-α), and alleviated pathological abnormalities induced by jellyfish venom. Additionally, DAP intervention significantly decreased the hemolysis rate and improved the viability of RAW264.7 cells, while reducing cell apoptosis and oxidative stress. Transcriptome analysis and western blotting of RAW264.7 cells further confirmed that DAP inhibited the activation of the NF-κB and MAPK signaling pathways. Overall, DAP effectively countered the toxicity of jellyfish venom by reducing oxidative damage and inflammatory response, highlighting the potential of TCM in treating jellyfish stings.

Recent progress of protein kinase inhibitors derived from marine peptides for developing anticancer agents

Protein kinases, mediating their biological function via their catalytic activity, play important role in cell development, including cell proliferation, migration, angiogenesis and survival. Over the years, protein kinase inhibitors have been developed as an important class of anticancer agents clinically. However, the off-targeting and drug resistance of protein kinase inhibitors limit their efficiency. Anticancer peptides derived from marine organisms represent a novel class of bioactive substances, and some of the peptides exhibit anticancer effect via inhibiting protein kinases. In this mini review, the recent progress of anticancer peptides targeting protein kinases from marine sources are presented. Marine peptides inhibiting resistant cancer cells by targeting novel domains of protein kinases are highlighted. The challenges and prospects of developing marine peptides as anticancer agents are also discussed.

Selective cytotoxicity of standardised n-hexane extract of black soldier flies' larvae on cancerous skin cells mitochondria isolated from rat model of melanoma

INTRODUCTION

Melanoma is known as a highly lethal cancer. In melanoma cells, apoptosis signalling which relies heavily on the acute activity of mitochondria and reactive oxygen species (ROS) formation is suppressed. Our previous studies on natural compounds on melanoma suggested that mitochondria are a potential target for the melanoma treatment by selective cytotoxic effect of them. The black soldier fly is an important environmental protectant insect that based on recent studies induces apoptosis in liver and colorectal carcinoma cells through the activation of caspase 3, 8, and 9 and ultimately inhibits the growth of cancer cells.

PURPOSE

This study was designed to evaluate the selective apoptotic effect of the n-hexane BSFL extract (BSFLE) on skin mitochondria.

MATERIALS AND METHODS

The mitochondria isolated from melanoma cells were treated with various concentrations (1500, 3000, and 6000 µg/ml) of n-hexane BSFLE Then MTT viability assay, ROS determination, Mitochondrial Membrane Potential (MMP), mitochondrial swelling, cytochrome c release determination, and % apoptosis were performed.

RESULTS

MTT assay showed that different concentrations of n-hexane BSFLE significantly (P < 0.05) decreased the SDH activity in cancerous skin mitochondria with the IC50. The ROS production and mitochondrial swelling results also showed that all concentrations of BSFL extracts significantly increased. MMP decline and the release of cytochrome c in cancer groups mitochondria. BSFLE increased apoptosis on melanoma cells.

DISCUSSION AND CONCLUSION

It is suggested that n-hexane BSFLE compounds selectively induce a cascade of proapoptotic events that are probably defective in cancer cells. Most of these compounds target the mitochondrial transient pore caused by disruption of the mitochondrial respiratory chain. These events lead to disruption of the temporary permeability of mitochondria, swelling of mitochondria and finally the formation of apoptosome in the cytosol.

A Novel Workflow for In Silico Prediction of Bioactive Peptides: An Exploration of Solanum lycopersicum By-Products

Resource-intensive processes currently hamper the discovery of bioactive peptides (BAPs) from food by-products. To streamline this process, in silico approaches present a promising alternative. This study presents a novel computational workflow to predict peptide release, bioactivity, and bioavailability, significantly accelerating BAP discovery. The computational flowchart has been designed to identify and optimize critical enzymes involved in protein hydrolysis but also incorporates multi-enzyme screening. This feature is crucial for identifying the most effective enzyme combinations that yield the highest abundance of BAPs across different bioactive classes (anticancer, antidiabetic, antihypertensive, anti-inflammatory, and antimicrobial). Our process can be modulated to extract diverse BAP types efficiently from the same source. Here, we show the potentiality of our method for the identification of diverse types of BAPs from by-products generated from Solanum lycopersicum, the widely cultivated tomato plant, whose industrial processing generates a huge amount of waste, especially tomato peel. In particular, we optimized tomato by-products for bioactive peptide production by selecting cultivars like Line27859 and integrating large-scale gene expression. By integrating these advanced methods, we can maximize the value of by-products, contributing to a more circular and eco-friendly production process while advancing the development of valuable bioactive compounds.

A review on marine source as anticancer agents

This review investigates the potential of natural compounds obtained from marine sources for the treatment of cancer. The oceans are believed to contain physiologically active compounds, such as alkaloids, nucleosides, macrolides, and polyketides, which have shown promising effects in slowing human tumor cells both in vivo and in vitro. Various marine species, including algae, mollusks, actinomycetes, fungi, sponges, and soft corals, have been studied for their bioactive metabolites with diverse chemical structures. The review explores the therapeutic potential of various marine-derived substances and discusses their possible applications in cancer treatment.

Bioactive Peptides from Marine Organisms

Marine organisms represent promising bioactive peptide resources with diverse biological activities such as antioxidant, antimicrobial, antihypertensive, anti-fatigue, and immunoregulatory activities. Despite many studies on marine bioactive peptides, there is a dearth of comprehensive review articles on the emerging trends that encompass the production techniques and the biological applications of marine bioactive peptides. In this review, we summarize the major research and findings related to marine bioactive peptides, encompassing aspects of their production, purification, biological activities, nanotechnology-based strategies, and their potential applications. Enzymatic hydrolysis currently stands out as the most commonly used method for producing marine bioactive peptides; the downstream purification process often includes a combination of multiple purification techniques. Due to their diverse biological properties, marine peptides have garnered considerable interest for industrial applications as active ingredients in the food, pharmaceutical, and cosmetics industries. Additionally, the incorporation of encapsulation strategies such as nano emulsion, nanoliposome, and microemulsions holds promise for significantly enhancing the bioavailability and bioactivity of marine peptides. Future research should also prioritize the systematic identification and validation of the potential health benefits of marine peptides by both in vitro and in vivo animal models, along with the conduct of human clinical trials.

Proteomic characterization and biological activities of the mucus produced by the zoanthid Palythoa caribaeorum (Duchassaing & Michelotti, 1860)

Mucus, produced by Palythoa caribaeorum has been popularly reported due to healing, anti-inflammatory, and analgesic effects. However, biochemical and pharmacological properties of this mucus remains unexplored. Therefore, the present study aimed to study its proteome profile by 2DE electrophoresis and MALDI-TOF. Furthermore, it was evaluated the cytotoxic, antibacterial, and antioxidant activities of the mucus and from its protein extract (PE). Proteomics study identified14 proteins including proteins involved in the process of tissue regeneration and death of tumor cells. The PE exhibited cell viability below 50% in the MCF-7 and S-180 strains. It showed IC50 of 6.9 μg/mL for the J774 lineage, and also, favored the cellular growth of fibroblasts. Furthermore, PE revealed activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus epidermidis (MIC of 250 μg/mL). These findings revealed the mucus produced by Palythoa caribaeorum with biological activities, offering alternative therapies for the treatment of cancer and as a potential antibacterial agent.

Nanotechnology-empowered strategies in treatment of skin cancer

In current scenario skin cancer is a serious condition that has a significant impact on world health. Skin cancer is divided into two categories: melanoma skin cancer (MSC) and non-melanoma skin cancer (NMSC). Because of its significant psychosocial effects and need for significant investment in new technology and therapies, skin cancer is an illness of global health relevance. From the patient's perspective chemotherapy considered to be the most acceptable form of treatment. However, significant negatives of chemotherapy such as severe toxicities and drug resistance pose serious challenges to the treatment. The field of nanomedicine holds significant promise for enhancing the specificity of targeting neoplastic cells through the facilitation of targeted drug delivery to tumour cells. The integration of multiple therapeutic modalities to selectively address cancer-promoting or cell-maintaining pathways constitutes a fundamental aspect of cancer treatment. The use of mono-therapy remains prevalent in the treatment of various types of cancer, it is widely acknowledged in the academic community that this conventional approach is generally considered to be less efficacious compared to the combination treatment strategy. The employment of combination therapy in cancer treatment has become increasingly widespread due to its ability to produce synergistic anticancer effects, mitigate toxicity associated with drugs, and inhibit multi-drug resistance by means of diverse mechanisms. Nanotechnology based combination therapy represents a promising avenue for the development of efficacious therapies for skin cancer within the context of this endeavour. The objective of this article is to provide a description of distinct challenges for efficient delivery of drugs via skin. This article also provides a summary of the various nanotechnology based combinatorial therapy available for skin cancer with their recent advances. This review also focuses on current status of clinical trials of such therapies.

Non-Canonical Amino Acids as Building Blocks for Peptidomimetics: Structure, Function, and Applications

This review provides a fresh overview of non-canonical amino acids and their applications in the design of peptidomimetics. Non-canonical amino acids appear widely distributed in nature and are known to enhance the stability of specific secondary structures and/or biological function. Contrary to the ubiquitous DNA-encoded amino acids, the structure and function of these residues are not fully understood. Here, results from experimental and molecular modelling approaches are gathered to classify several classes of non-canonical amino acids according to their ability to induce specific secondary structures yielding different biological functions and improved stability. Regarding side-chain modifications, symmetrical and asymmetrical α,α-dialkyl glycines, Cα to Cα cyclized amino acids, proline analogues, β-substituted amino acids, and α,β-dehydro amino acids are some of the non-canonical representatives addressed. Backbone modifications were also examined, especially those that result in retro-inverso peptidomimetics and depsipeptides. All this knowledge has an important application in the field of peptidomimetics, which is in continuous progress and promises to deliver new biologically active molecules and new materials in the near future.

Impact of nanotechnology on the oral delivery of phyto-bioactive compounds

Nanotechnology is an advanced field that has remarkable nutraceutical and food applications. Phyto-bioactive compounds (PBCs) play critical roles in promoting health and disease treatment. However, PBCs generally encounter several limitations that delay their widespread application. For example, most PBCs have low aqueous solubility, poor biostability, poor bioavailability, and a lack of target specificity. Moreover, the high concentrations of effective PBC doses also limit their application. As a result, encapsulating PBCs into an appropriate nanocarrier may increase their solubility and biostability and protect them from premature degradation. Moreover, nanoencapsulation could improve absorption and prolong circulation with a high opportunity for targeted delivery that may decrease unwanted toxicity. This review addresses the main parameters, variables, and barriers that control and affect oral PBC delivery. Moreover, this review discusses the potential role of biocompatible and biodegradable nanocarriers in improving the water solubility, chemical stability, bioavailability, and specificity/selectivity of PBCs.

An In Vitro Evaluation of the Potential Neuroprotective Effects of Intranasal Lipid Nanoparticles Containing Astaxanthin Obtained from Different Sources: Comparative Studies

The intranasal route has been suggested as a promising alternative to improve the direct transport of molecules to the brain, avoiding the need to cross the blood-brain barrier (BBB). In this area, the use of lipid nanoparticles, namely solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), has been highlighted as a promising strategy to improve the treatment of neurodegenerative diseases. In this work, formulations containing SLN and NLC that were loaded with astaxanthin that was obtained from different sources (astaxanthin extract (AE) from the algae Haematococcus pluvialis and pure astaxanthin (PA) from the fungi Blakeslea trispora) were prepared for nose-to-brain administration, and comparative in vitro experiments were performed to evaluate the biocompatibility of the formulations with nasal (RPMI 2650) and neuronal (SH-SY5Y) cells. Afterwards, the antioxidant activity of the formulations was evaluated for its potential neuroprotective effects, using different chemical aggressors. Finally, the cellular uptake of the astaxanthin was evaluated for the formulations that showed the greatest neuroprotection of the neuronal cells against chemical-induced damage. On the production day, all the formulations showed a particle size, a high encapsulation efficiency (EE), the presence of nanoparticles with a typical spherical shape, and a polydispersity index (PDI) and zeta potential (ZP) that are suitable for nose-to-brain administration. After three months of storage at room temperature, no significant changes were observed in the characterization parameters, predicting a good long-term stability. Furthermore, these formulations were shown to be safe with concentrations of up to 100 µg/mL in differentiated SH-SY5Y and RPMI 2650 cells. Regarding neuroprotection studies, the PA-loaded SLN and NLC formulations showed an ability to counteract some mechanisms of neurodegeneration, including oxidative stress. Moreover, when compared with the PA-loaded SLN, the PA-loaded NLC showed greater neuroprotective effects against the cytotoxicity induced by aggressors. In contrast, the AE-loaded SLN and NLC formulations showed no significant neuroprotective effects. Although further studies are needed to confirm these neuroprotective effects, the results of this study suggest that the intranasal administration of PA-loaded NLC may be a promising alternative to improve the treatment of neurodegenerative diseases.

Toxicity of Persian Gulf shell-less marine mollusc (Peronia peronii) methanolic extract on melanoma tumor mitochondria

INTRODUCTION

Melanoma is known as an aggressive and highly lethal cancer. The poor prognosis and resistance to treatment are characteristics of melanoma. In melanoma cells, apoptosis signaling which relies heavily on the acute activity of mitochondria and reactive oxygen species (ROS) formation is suppressed. Studies have shown that compounds isolated from marine herbs and animals, have been shown to have cytotoxic consequences on cancerous cells in prior research. This study was designed to evaluate the apoptotic effect of methanolic extract of Persian Gulf shell-less marine mollusc (Peronia peronii) on skin mitochondria isolated from animal model of melanoma.

PURPOSE

Melanoma mitochondria obtained from skin of melanoma animal model are studied in this research to see whether extracts from Persian Gulf shell-less marine mollusc (Peronia peronii), has a cytotoxic impact on them.

MATERIAL AND METHOD

In this study, the mitochondria were isolated from melanoma cells via differential centrifugation were treated with various concentrations (650, 1300 and 2600 µg/ml) of methanolic extract of Peronia peronii. Then MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) viability assay, Reactive oxygen species (ROS) determination, Mitochondrial Membrane Potential (MMP) decline assay, mitochondrial swelling and cytochrome c release determination were performed. Flow cytometry assay of % apoptotic vs necrotic phenotypes was also performed on extract treated melanoma cells.

RESULTS

The results of MTT assay showed that different concentrations of Peronia peronii extract significantly (P < 0.05) decreased the SDH activity in cancerous skin mitochondria with the IC50(1300 μg/ml). The ROS results also showed that all concentrations of Peronia peronii extracts significantly increased ROS production, MMP decline and the release of cytochrome c in cancer groups mitochondria. The swelling of mitochondria was significantly increased compared to the control group. In addition, the results of apoptosis assay showed that addition of root extract of Peronia peronii on melanoma cells increased apoptosis, while it had no effect on control non tumour cells.

DISCUSSION AND CONCLUSION

Based on these results, the presence of potentially bioactive compounds in Peronia peronii make this Persian Gulf coastal herb a strong candidate for further molecular studies and clinical research in the field of melanoma cancer therapy.

Intranasal Lipid Nanoparticles Containing Bioactive Compounds Obtained from Marine Sources to Manage Neurodegenerative Diseases

Marine sources contain several bioactive compounds with high therapeutic potential, such as remarkable antioxidant activity that can reduce oxidative stress related to the pathogenesis of neurodegenerative diseases. Indeed, there has been a growing interest in these natural sources, especially those resulting from the processing of marine organisms (i.e., marine bio-waste), to obtain natural antioxidants as an alternative to synthetic antioxidants in a sustainable approach to promote circularity by recovering and creating value from these bio-wastes. However, despite their expected potential to prevent, delay, or treat neurodegenerative diseases, antioxidant compounds may have difficulty reaching the brain due to the need to cross the blood-brain barrier (BBB). In this regard, alternative delivery systems administered by different routes have been proposed, including intranasal administration of lipid nanoparticles, such as solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), which have shown promising results. Intranasal administration shows several advantages, including the fact that molecules do not need to cross the BBB to reach the central nervous system (CNS), as they can be transported directly from the nasal cavity to the brain (i.e., nose-to-brain transport). The benefits of using SLN and NLC for intranasal delivery of natural bioactive compounds for the treatment of neurodegenerative diseases have shown relevant outcomes through in vitro and in vivo studies. Noteworthy, for bioactive compounds obtained from marine bio-waste, few studies have been reported, showing the open potential of this research area. This review updates the state of the art of using SLN and NLC to transport bioactive compounds from different sources, in particular, those obtained from marine bio-waste, and their potential application in the treatment of neurodegenerative diseases.

Absolute Stereochemistry Determination of Bioactive Marine-Derived Cyclopeptides by Liquid Chromatography Methods: An Update Review (2018-2022)

Cyclopeptides are considered as one of the most important classes of compounds derived from marine sources, due to their structural diversity and a myriad of their biological and pharmacological activities. Since marine-derived cyclopeptides consist of different amino acids, many of which are non-proteinogenic, they possess various stereogenic centers. In this respect, the structure elucidation of new molecular scaffolds obtained from natural sources, including marine-derived cyclopeptides, can become a very challenging task. The determination of the absolute configurations of the amino acid residues is accomplished, in most cases, by performing acidic hydrolysis, followed by analyses by liquid chromatography (LC). In a continuation with the authors' previous publication, and to analyze the current trends, the present review covers recently published works (from January 2018 to November 2022) regarding new cyclopeptides from marine organisms, with a special focus on their biological/pharmacological activities and the absolute stereochemical assignment of the amino acid residues. Ninety-one unreported marine-derived cyclopeptides were identified during this period, most of which displayed anticancer or antimicrobial activities. Marfey's method, which involves LC, was found to be the most frequently used for this purpose.

Bioactive peptides for anticancer therapies

Cancer is a serious concern in public health worldwide. Numerous modalities including surgery, radiotherapy, and chemotherapy, have been used for cancer therapies in clinic. Despite progress in anticancer therapies, the usage of these methods for cancer treatment is often related to deleterious side effects and multidrug resistance of conventional anticancer drugs, which have prompted the development of novel therapeutic methods. Anticancer peptides (ACPs), derived from naturally occurring and modified peptides, have received great attention in these years and emerge as novel therapeutic and diagnostic candidates for cancer therapies, because of several advantages over the current treatment modalities. In this review, the classification and properties of ACPs, the mode of action and mechanism of membrane disruption, as well as the natural sources of bioactive peptides with anticancer activities were summarised. Because of their high efficacy for inducing cancer cell death, certain ACPs have been developed to work as drugs and vaccines, evaluated in varied phases of clinical trials. We expect that this summary could facilitate the understanding and design of ACPs with increased specificity and toxicity towards malignant cells and with reduced side effects to normal cells.

Bioactive Peptides: Potential Impact on the Treatment of Gastrointestinal Cancers

We have reviewed the potential use of bioactive peptides in the treatment of gastrointestinal (GI) malignancies, which are a significant cause of morbidity and mortality globally. Conventional therapies, such as surgery, chemotherapy, and radiotherapy, are associated with numerous side effects that may lead to longterm complications. Bioactive peptides are short-chain amino acids that can be extracted from natural sources or synthesized, and they have various potential health benefits, including anti-inflammatory, anti-hypertensive, antioxidant, antimicrobial, and anti-cancer properties. Bioactive peptides can be acquired from animal or plant sources, and can be classified based on their function, such as ACE-inhibiting, antimicrobial, and electrolyte- regulating peptides. Recent studies have demonstrated the promising role of bioactive peptides in tumor suppression, especially when combined with conventional therapies. In this study, we have reviewed the beneficial properties of bioactive peptides and their role in suppressing tumor activity. The mechanisms of bioactive peptides in tumor suppression are discussed. We have further reviewed the findings of preclinical and clinical studies that have investigated the application of bioactive peptides in the treatment of GI cancers. This review highlights the potential use of bioactive peptides as a promising treatment method for GI malignancies to increase the quality of life of GI cancer patients.

iACP-GE: accurate identification of anticancer peptides by using gradient boosting decision tree and extra tree

Cancer is one of the main diseases threatening human life, accounting for millions of deaths around the world each year. Traditional physical and chemical methods for cancer treatment are extremely time-consuming, lab-intensive, expensive, inefficient and difficult to be applied in a high-throughput way. Hence, it is an urgent task to develop automated computational methods to enable fast and accurate identification of anticancer peptides (ACPs). In this paper, we develop a novel model named iACP-GE to identify ACPs. Multi-features are extracted by using binary encoding, enhanced grouped amino acid composition and BLOSUM62 encoding based on the N5C5 sequence, as well as detrended forward moving-average auto-cross correlation analysis based on physicochemical properties of 20 natural amino acids. Thus, 835 features are obtained for each sample, in order to avoid information redundancy, gradient boosting decision tree was adopted as the feature selection strategy. Then, the optimal feature subset is input to the extra tree classifier. The accuracies of ACP740 and ACP240 datasets with the 5-fold cross-validation were 90.54% and 91.25%, respectively. Experimental results indicate that iACP-GE significantly outperforms several existing models on ACP740 and ACP240 datasets and can be used as an effective tool for the identification of ACPs. The datasets and source codes for iACP-GE are available at https://github.com/yunyunliang88/iACP-GE.

Serum metabolic effects of corn oligopeptides with 7-day supplementation on early post-surgery primary liver cancer patients: a double-blind randomized controlled trial

BACKGROUND

Liver cancer as the main leading cancer has caused heavy burdens globally. The prognosis of liver cancer is closely related with postoperative nutrition support. Corn oligopeptides (COPs) are protein hydrolysates produced by enzymatic treatments, which have shown potential bioactivities, such as inhibiting angiotensin I-converting enzyme, resisting lipid peroxidation and anti-oxidant. However, the correlation between COPs and liver cancer patients is still unknown and the potential mechanism of COPs on liver cancer is unclear as well. The aim of this study was to assess effects of 7-day intervention of COPs after surgery on liver function and serum metabolic profiles of liver cancer patients.

METHODS

Patients were assigned into COPs intervention group (n=50) and control group (n=91) for 7 days. Investigations were scheduled at 1st day and 7th day after liver resection surgery respectively, mainly including anthropometric, biochemical indexes and liquid chromatography-mass spectrometry (LC/MS) analysis.

RESULTS

Seven-day supplementation of COPs on early post-surgery liver cancer patients down-regulated levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin and up-regulated prothrombin time activity and prealbumin levels. LC/MS analysis revealed metabolic signatures including regulation of 16 metabolites, which was closely related with two metabolic pathways (nicotinate and nicotinamide metabolism, fatty acid metabolism).

CONCLUSIONS

COPs supplementation has displayed the potentials on alleviating the injury of liver function and it may be due to regulation of fatty acid metabolism, nicotinate and nicotinamide metabolism, lipid peroxidation and anti-inflammatory action. More researches are warranted in future to confirm the exact mechanisms.

Water-Based Dynamic Depsipeptide Chemistry: Building Block Recycling and Oligomer Distribution Control Using Hydration-Dehydration Cycles

The high kinetic barrier to amide bond formation has historically placed narrow constraints on its utility in reversible chemistry applications. Slow kinetics has limited the use of amides for the generation of diverse combinatorial libraries and selection of target molecules. Current strategies for peptide-based dynamic chemistries require the use of nonpolar co-solvents or catalysts or the incorporation of functional groups that facilitate dynamic chemistry between peptides. In light of these limitations, we explored the use of depsipeptides: biorelevant copolymers of amino and hydroxy acids that would circumvent the challenges associated with dynamic peptide chemistry. Here, we describe a model system of N-(α-hydroxyacyl)-amino acid building blocks that reversibly polymerize to form depsipeptides when subjected to two-step evaporation-rehydration cycling under moderate conditions. The hydroxyl groups of these units allow for dynamic ester chemistry between short peptide segments through unmodified carboxyl termini. Selective recycling of building blocks is achieved by exploiting the differential hydrolytic lifetimes of depsipeptide amide and ester bonds, which we show are controllable by adjusting the solution pH, temperature, and time as well as the building blocks' side chains. We demonstrate that the polymerization and breakdown of the depsipeptides are facilitated by cyclic morpholinedione intermediates, and further show how structural properties dictate half-lives and product oligomer distributions using multifunctional building blocks. These results establish a cyclic mode of ester-based reversible depsipeptide formation that temporally separates the polymerization and depolymerization steps for the building blocks and may have implications for prebiotic polymer chemical evolution.

Marine Cyclic Peptides: Antimicrobial Activity and Synthetic Strategies

Oceans are a rich source of structurally unique bioactive compounds from the perspective of potential therapeutic agents. Marine peptides are a particularly interesting group of secondary metabolites because of their chemistry and wide range of biological activities. Among them, cyclic peptides exhibit a broad spectrum of antimicrobial activities, including against bacteria, protozoa, fungi, and viruses. Moreover, there are several examples of marine cyclic peptides revealing interesting antimicrobial activities against numerous drug-resistant bacteria and fungi, making these compounds a very promising resource in the search for novel antimicrobial agents to revert multidrug-resistance. This review summarizes 174 marine cyclic peptides with antibacterial, antifungal, antiparasitic, or antiviral properties. These natural products were categorized according to their sources—sponges, mollusks, crustaceans, crabs, marine bacteria, and fungi—and chemical structure—cyclic peptides and depsipeptides. The antimicrobial activities, including against drug-resistant microorganisms, unusual structural characteristics, and hits more advanced in (pre)clinical studies, are highlighted. Nocathiacins I–III (91–93), unnarmicins A (114) and C (115), sclerotides A (160) and B (161), and plitidepsin (174) can be highlighted considering not only their high antimicrobial potency in vitro, but also for their promising in vivo results. Marine cyclic peptides are also interesting models for molecular modifications and/or total synthesis to obtain more potent compounds, with improved properties and in higher quantity. Solid-phase Fmoc- and Boc-protection chemistry is the major synthetic strategy to obtain marine cyclic peptides with antimicrobial properties, and key examples are presented guiding microbiologist and medicinal chemists to the discovery of new antimicrobial drug candidates from marine sources.

Bioactive peptide inhibits acute myeloid leukemia cell proliferation by downregulating ALKBH5-mediated m6A demethylation of EIF4EBP1 and MLST8 mRNA

Purpose

N6-methyladenosine (m⁶A), the most prevalent mRNA modification, plays an essential role in tumorigenesis. Notably, increasing interest has been directed to bioactive peptides (BPs) with antitumor activities. Here, we set out to investigate the potential of the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis on prevention and treatment of acute myeloid leukemia (AML).

Methods

The biological effects of BP on AML cells were detected by MTT and ApoLive-Glo™ multiplex assays. The role of BP in tumor growth was determined by a subcutaneous xenograft model. The ALKBH5/MLST8/EIF4EBP1 axis was identified as a potential BP target in AML via methylated RNA immunoprecipitation sequencing (MeRIP-seq) combined with RNA sequencing (RNA-seq). Western blot, RT-qPCR, MeRIP-qPCR, dual-luciferase reporter and RNA stability assays were performed to validate the function and mode of action of the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis. The clinical relevance of the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis in AML was confirmed by TCGA data analysis.

Results

We found that BP can inhibit AML cell proliferation and promote apoptosis in vitro, and repress AML tumor growth in vivo. Mechanistically, we found that BP downregulated ALKBH5 expression, which in turn repressed m⁶A demethylation of MLST8 and EIF4EBP1 mRNAs. Reduction of the m⁶A levels of MLST8 and EIF4EBP1 facilitated MLST8 and EIF4EBP1 mRNA decay, resulting in inhibition of AML cell proliferation. Furthermore, we found that the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis closely correlates with AML patient prognosis.

Conclusions

Our data indicate that BP can inhibit acute myeloid leukemia cell proliferation by downregulating ALKBH5-mediated m⁶A demethylation of EIF4EBP1 and MLST8 mRNAs, which may have potential to prevent and treat this disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13402-022-00666-9.

Synthesis of Marine Cyclopeptide Galaxamide Analogues as Potential Anticancer Agents

In this paper, eight new galaxamide analogues (Z-1~Z-8) were synthesized and evaluated for their cytotoxic activities against five cancer cell lines, MCF-7, MD-MBA-231, HepG2, Hela, and A549, using MTT assays. The modified analogue Z-6 displayed broad spectrum cytotoxic activity toward each tested cell line with IC₅₀ values of 1.65 ± 0.30 (MCF-7), 2.91 ± 0.17 (HepG2), 4.59 ± 0.27 (MD-MBA-231), 5.69 ± 0.37 (Hela), and 5.96 ± 0.41 (A549) μg/mL, respectively. The galaxamides Z-3 and Z-6 induced concentration-dependent apoptosis of the MCF-7 cells after 72 h as evaluated by the flow cytometry experiment. The results showed that these compounds could induce MCF-7 cell apoptosis by arresting the G0/G1 phase of the cell cycle and finally achieving the effect of inhibiting the proliferation of MCF-7 cells.

Microbial diversity of garden snail mucus

The search for new natural compounds for application in medicine and cosmetics is a trend in biotechnology. One of the sources of such active compounds is the snail mucus. Snail physiology and the biological activity of their fluids (especially the mucus) are still poorly studied. Only a few previous studies explored the relationship between snails and their microbiome. The present study was focused on the biodiversity of the snail mucus used in the creation of cosmetic products, therapeutics, and nutraceuticals. The commonly used cultivation techniques were applied for the determination of the number of major bacterial groups. Fluorescence in situ hybridization for key taxa was performed. The obtained images were subjected to digital image analysis. Sequencing of the 16S rRNA gene was also done. The results showed that the mucus harbors a rich bacterial community (10.78 × 1010  CFU/ml). Among the dominant bacteria, some are known for their ability to metabolize complex polysaccharides or are usually found in soil and plants (Rhizobiaceae, Shewanella, Pedobacter, Acinetobacter, Alcaligenes). The obtained data demonstrated that the snail mucus creates a unique environment for the development of the microbial community that differs from other parts of the animal and which resulted from the combined contribution of the microbiomes derived from the soil, plants, and the snails.

Fish Gelatin: Current Nutritional, Medicinal, Tissue Repair Applications and Carrier of Drug Delivery

Gelatin is obtained via partial denaturation of collagen and is extensively used in various industries. The majority of gelatin utilized globally is derived from a mammalian source. Several health and religious concerns associated with porcine/bovine gelatin were reported. Therefore, gelatin from a marine source is widely being investigated for its efficiency and utilization in a variety of applications as a potential substitute for porcine/bovine gelatin. Although fish gelatin is less durable and possesses lower melting and gelling temperatures compared to mammal-derived gelatin, various modifications are being reported to promote its rheological and functional properties to be efficiently employed. The present review describes in detail the current innovative applications of fish gelatin involving the food industry, drug delivery and possible therapeutic applications. Gelatin bioactive molecules may be utilized as carriers for drug delivery. Due to its versatility, gelatin can be used in different carrier systems, such as microparticles, nanoparticles, fibers and hydrogels. The present review also provides a perspective on the other potential pharmaceutical applications of fish gelatin, such as tissue regeneration, antioxidant supplementation, antihypertensive and anticancer treatments.

Marine Depsipeptide Nobilamide I Inhibits Cancer Cell Motility and Tumorigenicity via Suppressing Epithelial-Mesenchymal Transition and MMP2/9 Expression

A cyclic depsipeptide, nobilamide I (1), along with the known peptide A-3302-B/TL-119 (2), was isolated from the saline cultivation of the marine-derived bacterium Saccharomonospora sp., strain CNQ-490. The planar structure of 1 was elucidated by interpretation of 1D and 2D NMR and MS spectroscopic data. The absolute configurations of the amino acids in 1 were assigned by using the C₃ Marfey's analysis and comparing them with those of 2 based on their biosynthetic pathways. Nobilamide I (1) decreased cell motility by inhibiting epithelial-mesenchymal transition markers in A549 (lung cancer), AGS (gastric cancer), and Caco2 (colorectal cancer) cell lines. In addition, 1 modulated the expression of the matrix metalloproteinase (MMP) family (MMP2 and MMP9) in the three cell lines.

Anti-lung Cancer Marine Compounds: A Review

Lung cancer is one of the most common and lethal cancers in human beings. Lung cancer has been divided into two major types: small cell lung cancer (SCLC) and non-small cell lung carcinoma (NSCLC). Current drugs suffer from various side effects, and the insufficient efficacy of present treatments creates a desire for better more efficient new drugs. This review compares the diversity of marine-derived bioactive compounds from different marine species. Some of the natural products from marine resources are in different stages of clinical trials. By the way, most of them have been studied in vitro and in vivo. Additionally, in this review, the mechanisms of action of marine-derived anti-lung cancer components on lung cancer cell lines have been reviewed. In addition, considering growing rate and the high costs of cancer research, attention must be paid to some aspects of targeting and developing anti-lung cancer drug. In better words, like the other therapeutic strategies that have their particular challenges and weak points, several challenges about marine-derived anti-lung cancer components which exist for scientists for doing research are explained. Moreover, as the attentions in the field of cancer therapy are focused on designing and developing new anticancer strategies for the treatment of cancer in the future, the application of marine-derived anti-lung cancer components in the field of future cancer therapy and their role in future anticancer strategies are briefly discussed.

A Novel Gelatinase from Marine Flocculibacter collagenilyticus SM1988: Characterization and Potential Application in Collagen Oligopeptide-Rich Hydrolysate Preparation

Although the S8 family in the MEROPS database contains many peptidases, only a few S8 peptidases have been applied in the preparation of bioactive oligopeptides. Bovine bone collagen is a good source for preparing collagen oligopeptides, but has been so far rarely applied in collagen peptide preparation. Here, we characterized a novel S8 gelatinase, Aa2_1884, from marine bacterium Flocculibacter collagenilyticus SM1988^T, and evaluated its potential application in the preparation of collagen oligopeptides from bovine bone collagen. Aa2_1884 is a multimodular S8 peptidase with a distinct domain architecture from other reported peptidases. The recombinant Aa2_1884 over-expressed in Escherichia coli showed high activity toward gelatin and denatured collagens, but no activity toward natural collagens, indicating that Aa2_1884 is a gelatinase. To evaluate the potential of Aa2_1884 in the preparation of collagen oligopeptides from bovine bone collagen, three enzymatic hydrolysis parameters, hydrolysis temperature, hydrolysis time and enzyme-substrate ratio (E/S), were optimized by single factor experiments, and the optimal hydrolysis conditions were determined to be reaction at 60 ℃ for 3 h with an E/S of 400 U/g. Under these conditions, the hydrolysis efficiency of bovine bone collagen by Aa2_1884 reached 95.3%. The resultant hydrolysate contained 97.8% peptides, in which peptides with a molecular weight lower than 1000 Da and 500 Da accounted for 55.1% and 39.5%, respectively, indicating that the hydrolysate was rich in oligopeptides. These results indicate that Aa2_1884 likely has a promising potential application in the preparation of collagen oligopeptide-rich hydrolysate from bovine bone collagen, which may provide a feasible way for the high-value utilization of bovine bone collagen.

Toward the Synthesis of a Heterocyclic Analogue of Natural Cyclooligopeptide with Improved Bio-Properties

AIMS

The present investigation is targeted toward the synthesis of a novel analogue of a natural peptide of marine origin. <P> Background: Marine sponges are enriched with bioactive secondary metabolites especially circular peptides. Heterocycles are established organic compounds with potential biological value. Taking into consideration the bio-properties of heterocycles and marine sponge-derived natural peptides, an effort was made for the synthesis of a heterocyclic analogue of a natural cyclopeptide. <P> Objective: A heterocyclic analogue of a sponge-derived proline-containing cyclic peptide, rolloamide A, was synthesized by interaction of Boc-protected L-histidinyl-L-prolyl-L-valine and L-prolyl-L-leucyl-L-prolyl-L-isoleucine methyl ester and compared with synthetic rolloamide A with bioactivity against bacteria, fungi, and earthworms. <P> Methods: The synthesis of cycloheptapeptide was accomplished employing the liquid phase method. The larger peptide segment was prepared by interaction of Boc-protected L-prolyl-L-leucine with L-prolyl-L-isoleucine methyl ester. Similarly, the tripeptide unit was synthesized from Boc-protected L-histidinyl-L-proline with L-valine ester. The linear heptapeptide segment (7) was cyclized by utilizing pentafluorophenyl (pfp) ester, and the structure was elucidated by elemental and spectral (IR, 1H/13C NMR, MS) analysis. The peptide was also screened for diverse bioactivities such as antibacterial, antifungal, and potential against earthworms and cytotoxicity. <P> Results: The novel cyclooligopeptide was synthesized with 84% yield by making use of carbodiimides. The synthesized cyclopeptide exhibited significant cytotoxicity against two cell lines. In addition, promising antifungal and antihelmintic properties were observed for newly synthesized heterocyclic peptide derivative (8) against dermatophytes and three earthworm species at 6 µg/mL and 2 mg/mL, respectively. <P> Conclusion: Solution-phase technique employing carbodiimide chemistry established to be promising for synthesizing the cycloheptapeptide derivative (8), and C5H5N was proved a better base for heptapeptide circling, when compared to N-methylmorpholine and triethylamine.

Therapeutic potential of marine peptides in glioblastoma: Mechanistic insights

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in humans. It is characterized by excessive cell growth and accelerated intrusion of normal brain tissue along with a poor prognosis. The current standard of treatment, including surgical removal, radiation therapy, and chemotherapy, is largely ineffective, with high mortality and recurrence rates. As a result, traditional approaches have evolved to include new alternative remedies, such as natural compounds. Aquatic species provide a rich supply of possible drugs. The physiological effects of marine peptides in glioblastoma are mediated by a range of pathways, including apoptosis, microtubule balance disturbances, suppression of angiogenesis, cell migration/invasion, and cell viability; autophagy and metabolic enzymes downregulation. Herein, we address the efficacy of marine peptides as putative safe therapeutic agents for glioblastoma coupled with detail molecular mechanisms.

Exploiting of Secondary Raw Materials from Fish Processing Industry as a Source of Bioactive Peptide-Rich Protein Hydrolysates

Developing peptide-based drugs are very promising to address many of the lifestyle mediated diseases which are prevalent in a major portion of the global population. As an alternative to synthetic peptide-based drugs, derived peptides from natural sources have gained a greater attention in the last two decades. Aquatic organisms including plants, fish and shellfish are known as a rich reservoir of parent protein molecules which can offer novel sequences of amino acids in peptides, having unique bio-functional properties upon hydrolyzing with proteases from different sources. However, rather than exploiting fish and shellfish stocks which are already under pressure due to overexploitation, the processing discards, regarded as secondary raw material, could be a potential choice for peptide based therapeutic development strategies. In this connection, we have attempted to review the scientific reports in this area of research that deal with some of the well-established bioactive properties, such as antihypertensive, anti-oxidative, anti-coagulative, antibacterial and anticarcinogenic properties, with reference to the type of enzymes, substrate used, degree of particular bio-functionality, mechanism, and wherever possible, the active amino acid sequences in peptides. Many of the studies have been conducted on hydrolysate (crude mixture of peptides) enriched with low molecular bioactive peptides. In vitro and in vivo experiments on the potency of bioactive peptides to modulate the human physiological functions beneficially have demonstrated that these peptides can be used in the prevention and treatment of non-communicable lifestyle mediated diseases. The information synthesized under this review could serve as a point of reference to drive further research on and development of functionally active therapeutic natural peptides. Availability of such scientific information is expected to open up new zones of investigation for adding value to underutilized secondary raw materials, which in turn paves the way for sustainability in fish processing. However, there are significant challenges ahead in exploring the fish waste as a source of bioactive peptides, as it demands more studies on mechanisms and structure–function relationship understanding as well as clearance from regulatory and statutory bodies before reaching the end user in the form of supplement or therapeutics.

Marine peptides in breast cancer: Therapeutic and mechanistic understanding

Breast cancer is the most prevalent invasive form of cancer in females and posing a great challenge for overcoming disease burden. The growth in global cancer deaths mandates the discovery of new efficacious natural anti-tumor treatments. In this regard, aquatic species offer a rich supply of possible drugs. Studies have shown that several marine peptides damage cancer cells by a broad range of pathways, including apoptosis, microtubule balance disturbances, and suppression of angiogenesis. Traditional chemotherapeutic agents are characterized by a plethora of side effects, including immune response suppression. The discovery of novel putative anti-cancer peptides with lesser toxicity is therefore necessary and timely, especially those able to thwart multi drug resistance (MDR). This review addresses marine anti-cancer peptides for the treatment of breast cancer.

Molecular Docking, G-QSAR Studies, Synthesis and Anticancer Screening of Some New 2-Phenazinamines as Bcr-Abl Tyrosine Kinase Inhibitors

BACKGROUND

The computational studies on 2-phenazinamines with their protein targets have been carried out to design compounds with potential anticancer activity. This strategy of designing compounds possessing selectivity over specific tyrosine kinase has been achieved through G-QSAR and molecular docking studies.

METHODS

The objective of this research has been to design newer 2-phenazinamine derivatives as Bcr-Abl tyrosine kinase inhibitors by G-QSAR, molecular docking studies followed by wet lab studies along with evaluation of their anticancer potential. Computational chemistry was done by using VLife MDS 4.3 and Autodock 4.2 followed by wet lab experiments for synthesizing 2- phenazinamine derivatives. The chemical structures of ligands in 2D were drawn by employing Chemdraw 2D Ultra 8.0 and were converted into 3D. These were optimised by using semiempirical method called MOPAC. The protein structure was retrieved from RCSC protein data bank as PDB file. The binding interactions of protein and ligands were done by using PYMOL. The molecular properties of the designed compounds were predicted in silico by using Osiris property explorer. Later, we synthesized novel 13 2-phenazinamine derivatives by treating parent compound with various aldehydes in the presence of dicyclohexylcarbodiimide (DCC) and urea to afford 2-(2-chlorophenyl)-3-(phenazin-2-yl) thiazolidin-4-one and another series of derivatives synthesized with different aldehydes in the presence of p-toluylsulphonic acid, diphydropyridine and benzene sulfonyl chloride to afford benzenesulfonyl-N-(2-chlorobenzyl)-phenazin-2-amine. All the derivatives were tested for invitro anticancer activity on K562 human chronic myelogenous leukemia cell line by employing MTT assay method.

RESULTS

The developed G-QSAR models were found to be statistically significant with respect to training (r2=0.8074), cross-validation (q2=0.6521), and external validation (pred_r2=0.5892). The best developed G-QSAR model suggested that the XlogP values of phenazinamine derivatives were found to be highly influential in determining biological activity. The standard drug was found to exhibit binding energy - 6.79 kcal/mol and the derivatives 5b and 6c exhibited binding energy of - 7.46 and - 8.51; respectively.

CONCLUSION

Compounds 5b, 6c were observed to possess good lipophilicity and were found to exhibit better activity than other compounds in the series, although less than standard doxorubicin. The synthesis of these 2-phenazinamine derivatives (5a-m) is reported to be obtained from 2,4- dinitrodiphenylamine by applying appropriate synthetic route. Compounds 5b and 6c showed better cytotoxic activity against K562 cancer cell line when compared to other compounds of the series, although less than standard doxorubicin.

Bio-Nanocarriers for Lung Cancer Management: Befriending the Barriers

Lung cancer is a complex thoracic malignancy developing consequential to aberrations in a myriad of molecular and biomolecular signaling pathways. It is one of the most lethal forms of cancers accounting to almost 1.8 million new annual incidences, bearing overall mortality to incidence ratio of 0.87. The dismal prognostic scenario at advanced stages of the disease and metastatic/resistant tumor cell populations stresses the requisite of advanced translational interdisciplinary interventions such as bionanotechnology. This review article deliberates insights and apprehensions on the recent prologue of nanobioengineering and bionanotechnology as an approach for the clinical management of lung cancer. The role of nanobioengineered (bio-nano) tools like bio-nanocarriers and nanobiodevices in secondary prophylaxis, diagnosis, therapeutics, and theranostics for lung cancer management has been discussed. Bioengineered, bioinspired, and biomimetic bio-nanotools of considerate translational value have been reviewed. Perspectives on existent oncostrategies, their critical comparison with bio-nanocarriers, and issues hampering their clinical bench side to bed transformation have also been summarized.

In Vitro Bioactivity of Astaxanthin and Peptides from Hydrolisates of Shrimp (Parapenaeus longirostris) By-Products: From the Extraction Process to Biological Effect Evaluation, as Pilot Actions for the Strategy "From Waste to Profit"

Non-edible parts of crustaceans could be a rich source of valuable bioactive compounds such as the carotenoid astaxanthin and peptides, which have well-recognized beneficial effects. These compounds are widely used in nutraceuticals and pharmaceuticals, and their market is rapidly growing, suggesting the need to find alternative sources. The aim of this work was to set up a pilot-scale protocol for the reutilization of by-products of processed shrimp, in order to address the utilization of this valuable biomass for nutraceutical and pharmaceuticals application, through the extraction of astaxanthin-enriched oil and antioxidant-rich protein hydrolysates. Astaxanthin (AST) was obtained using “green extraction methods,” such as using fish oil and different fatty acid ethyl esters as solvents and through supercritical fluid extraction (SFE), whereas bioactive peptides were obtained by protease hydrolysis. Both astaxanthin and bioactive peptides exhibited bioactive properties in vitro in cellular model systems, such as antioxidant and angiotensin I converting enzyme (ACE) inhibitory activities (IA). The results show higher astaxanthin yields in ethyl esters fatty acids (TFA) extraction and significant enrichment by short-path distillation (SPD) up to 114.80 ± 1.23 µg/mL. Peptide fractions of <3 kDa and 3–5 kDa exhibited greater antioxidant activity while the fraction 5–10 kDa exhibited a better ACE-IA. Lower-molecular-weight bioactive peptides and astaxanthin extracted using supercritical fluids showed protective effects against oxidative damage in 142BR and in 3T3 cell lines. These results suggest that “green” extraction methods allow us to obtain high-quality bioactive compounds from large volumes of shrimp waste for nutraceutical and pharmaceutical applications.

Proteins extracted from seaweed Undaria pinnatifida and their potential uses as foods and nutraceuticals

Isolation and utilization of proteins from seaweeds have been a novel trend in the world at present due to the increasing demand for healthy non-animal proteins. The attention of scientific community has been paid on the protein derived from seaweed Undaria pinnatifida due to their high nutritional quality and bioactivity. This article aims to provide an integrated overview on methods of extraction, isolation and purification of U. pinnatifida-derived proteins and composition, nutritional value and potential nutraceutical and food applications with an interest to stimulate further research to optimize the utilization. Potential food applications of U. pinnatifida derived proteins are nutritional components in human diet, food ingredients and additives, alternative meat and meat analogues and animal and fish feed. Excellent antioxidant, antihypertension, anticoagulant, anti-diabetes, antimicrobial and anti-cancer activities possessed by proteins of U. pinnatifida enable the use of these proteins in various nutraceutical applications. A number of studies have been carried out on antioxidant and antihypertensive activities of U. pinnatifida proteins, whereas other bioactivites are yet to be further studied. Hence, more research works are crucial to be done in order to facilitate and promote the emerging novel foods and nutraceuticals, using proteins from seaweed U. pinnatifida.

Shotgun Proteomics and Protein-Based Bioinformatics for the Characterization of Food-Derived Bioactive Peptides

A workflow for the characterization of food-derived bioactive peptides is described in this chapter. The workflow integrates two consecutive steps: a discovery phase and a protein-based bioinformatic phase. In the first step (discovery phase), a shotgun bottom-up proteomics approach is used to create a reference data set for a selected food proteome. Afterward, in a second step (bioinformatic phase), the reference proteome is subjected to several in silico protein-based bioinformatic analyses to predict and characterize potential bioactive peptides after an in silico human gastrointestinal digestion. Using this workflow, bioactive collagen peptides, antihypertensive, antimicrobial, and antitumor peptides were predicted as potential valuable bioactive peptides from seafood and marine by-products. It is concluded that the combination of the global shotgun proteomic analysis and the analysis by protein-based bioinformatics can provide a rapid strategy for the characterization of new potential food-derived bioactive peptides.

Synthesis and Bioactivity of a Cyclopolypeptide from Caribbean Marine Sponge

Synthesis of a natural proline-rich cyclopolypeptide - rolloamide A was carried out by coupling of tri- and tetrapeptide units Boc-Phe-Pro-Val-OMe and Boc-Pro-Leu-Pro-Ile-OMe after proper deprotection at carboxyl and amino terminals using carbodiimide chemistry in alkaline environment followed by cyclization of linear heptapeptide segment in the presence of base. The structure of synthesized peptide was confirmed by spectral techniques including FTIR, ¹H NMR, ¹³C NMR, MS analyses. Newly synthesized peptide was subjected to biological screening against pathogenic microbes and earthworms. Cyclopeptide 8 possessed promising activity against pathogenic fungi Candida albicans (ZOI: 24 mm, MIC: 6 μg/mL) and Gram-negative bacteria Pseudomonas aeruginosa (ZOI: 27 mm, MIC: 6 μg/mL) and Klebsiella pneumoniae (ZOI: 23 mm, MIC: 12.5 μg/mL), in comparison to reference drugs – griseofulvin (ZOI: 20 mm, MIC: 6 μg/mL) and ciprofloxacin (ZOI: 25 mm, MIC: 6 μg/mL/ZOI: 20 mm, MIC: 12.5 μg/mL). Also, newly synthesized heptacyclopeptide exhibited potent anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses, and Eudrilus species (MPT/MDT ratio – 8.22-16.02/10.06-17.59 min), in comparison to standard drugs - mebendazole (MPT/MDT ratio – 10.52-18.02/12.57-19.49 min) and piperazine citrate (MPT/MDT ratio – 12.38-19.17/13.44-22.17 min).

β-Carbolines as potential anticancer agents

β-Carbolines are indole alkaloids having a tricyclic pyrido[3,4-b]indole ring in their structure. Since the isolation of first β-carboline from Peganum harmala in 1841, the isolation and synthesis of various β-carboline derivatives surged in the following centuries. β-Carboline derivatives due to their widespread availability from natural sources, structural flexibility, quick reactivity and interaction with varied anticancer targets such as DNA (intercalation, groove binding, etc.), enzymes (GPX4, topoisomerases, kinases, etc.) and proteins (tubulin, ABCG2/BRCP1, etc.) have established themselves as promising lead compounds for the synthesis of various anticancer active agents. The current review covers the synthesis and isolation, anticancer activity, mechanism of action and SAR of various β-carboline containing molecules, its derivatives and congeners.

Functional and Bioactive Properties of Peptides Derived from Marine Side Streams

In fish processing, a great amount of side streams, including skin, bones, heads and viscera, is wasted or downgraded as feed on a daily basis. These side streams are rich sources of bioactive nitrogenous compounds and protein, which can be converted into peptides through enzymatic hydrolysis as well as bacterial fermentation. Peptides are short or long chains of amino acids differing in structure and molecular weight. They can be considered as biologically active as they can contribute to physiological functions in organisms with applications in the food and pharmaceutical industries. In the food industry, such bioactive peptides can be used as preservatives or antioxidants to prevent food spoilage. Furthermore, peptides contain several functional qualities that can be exploited as tools in modifying food ingredient solubility, water-holding and fat-binding capacity and gel formation. In the pharmaceutical industry, peptides can be used as antioxidants, but also as antihypertensive, anticoagulant and immunomodulatory compounds, amongst other functions. On the basis of their properties, peptides can thus be used in the development of functional foods and nutraceuticals. This review focuses on the bioactive peptides derived from seafood side streams and discusses their technological properties, biological activities and applications.

Marine-derived drugs: Recent advances in cancer therapy and immune signaling

The marine environment is an enormous source of marine-derived natural products (MNPs), and future investigation into anticancer drug discovery. Current progress in anticancer drugs offers a rise in isolation and clinical validation of numerous innovative developments and advances in anticancer therapy. However, only a limited number of FDA-approved marine-derived anticancer drugs are available due to several challenges and limitations highlighted here. The use of chitosan in developing marine-derived drugs is promising in the nanotech sector projected for a prolific anticancer drug delivery system (DDS). The cGAS-STING-mediated immune signaling pathway is crucial, which has not been significantly investigated in anticancer therapy and needs further attention. Additionally, a small range of anticancer mediators is currently involved in regulating various JAK/STAT signaling pathways, such as immunity, cell death, and tumor formation. This review addressed critical features associated with MNPs, origin, and development of anticancer drugs. Moreover, recent advances in the nanotech delivery of anticancer drugs and understanding into cancer immunity are detailed for improved human health.

Thomas O, Barraja P, Gaudêncio SP, Bertoni F. Marine Anticancer Agents: An Overview with a Particular Focus on Their Chemical Classes

The marine environment is a rich source of biologically active molecules for the treatment of human diseases, especially cancer. The adaptation to unique environmental conditions led marine organisms to evolve different pathways than their terrestrial counterparts, thus producing unique chemicals with a broad diversity and complexity. So far, more than 36,000 compounds have been isolated from marine micro- and macro-organisms including but not limited to fungi, bacteria, microalgae, macroalgae, sponges, corals, mollusks and tunicates, with hundreds of new marine natural products (MNPs) being discovered every year. Marine-based pharmaceuticals have started to impact modern pharmacology and different anti-cancer drugs derived from marine compounds have been approved for clinical use, such as: cytarabine, vidarabine, nelarabine (prodrug of ara-G), fludarabine phosphate (pro-drug of ara-A), trabectedin, eribulin mesylate, brentuximab vedotin, polatuzumab vedotin, enfortumab vedotin, belantamab mafodotin, plitidepsin, and lurbinectedin. This review focuses on the bioactive molecules derived from the marine environment with anticancer activity, discussing their families, origin, structural features and therapeutic use.

High-value compounds from the molluscs of marine and estuarine ecosystems as prospective functional food ingredients: An overview

Extensive biodiversity and availability of marine and estuarine molluscs, along with their their wide-range of utilities as food and nutraceutical resources developed keen attention of the food technologists and dieticians, particularly during the recent years. The current review comprehensively summarized the nutritional qualities, functional food attributes, and bioactive properties of these organisms. Among the phylum mollusca, Cephalopoda, Bivalvia, and Gastropoda were mostly reported for their nutraceutical applications and bioactive properties. The online search tools, like Scifinder/Science Direct/PubMed/Google Scholar/MarinLit database and marine natural product reports (1984-2019) were used to comprehend the information about the molluscs. More than 1334 secondary metabolites were reported from marine molluscs between the periods from 1984 to 2019. Among various classes of specialized metabolites, terpenes were occupied by 55% in gastropods, whereas sterols occupied 41% in bivalves. The marketed nutraceuticals, such as CadalminTM green mussel extract (Perna viridis) and Lyprinol® (Perna canaliculus) were endowed with potential anti-inflammatory activities, and were used against arthritis. Molluscan-derived therapeutics, for example, ziconotide was used as an analgesic, and elisidepsin was used in the treatment of cancer. Greater numbers of granted patents (30%) during 2016-2019 recognized the increasing importance of bioactive compounds from molluscs. Consumption of molluscs as daily diets could be helpful in the enhancement of immunity, and reduce the risk of several ailments. The present review comprehended the high value compounds and functional food ingredients from marine and estuarine molluscs.