Reactive oxygen species generation and mitochondrial dysfunction for the initiation of apoptotic cell death in human hepatocellular carcinoma HepG2 cells by a cyclic dipeptide Cyclo(-Pro-Tyr)

Characterization of the intestinal transport mechanism of polystyrene microplastics (MPs) and the potential inhibitory effect of green tea extracts on MPs intestinal absorption

The aims of the current study included characterizing the intestinal transport mechanism of polystyrene microplastics (MPs) with different charges and sizes in the intestinal epithelial cell model and determining the inhibitory effect of green tea extracts (GTEs) on the intestinal absorption of MPs in Caco-2 cells. The smaller sizes, which included diameters of 0.2 μm, of amine-modified MPs compared to either larger size (1 μm diameter, or carboxylate-MPs (0.2 and 1 μm diameter) significantly lowered the cell viability of caco-2 cells that were measured by MTT assay (p < 0.05). The transported amount (particles/mL of the cell media) of amine-modified MPs by the Caco-2 cell, was not dependent according to the concentrations, energy, or temperature, but it was higher than the carboxylate-modified MPs. The co-treatment of GTEs with the amine-modified MPs inhibited Caco-2 cell cytotoxicity as well as reduced the production of intracellular reactive oxygen species (ROS) in HepG2 generated by the exposure of amine-modified MPs. The GTEs co-treatment also increased trans-epithelial electrical resistances (TEER) and reduced the transportation of Lucifer Yellow via the Caco-2 monolayer compared to only the amine-modified MPs exposure. The GTEs treatment led to a decrease in the number of amine-modified MPs transported to the basal side of the Caco-2 monolayer. The results from our study suggest that the consumption of GTEs could enhance the intestinal barrier function by recovering intestinal epithelial cell damage induced by MPs, which resulted in a decrease of the intestinal absorption of MPs.

Antimicrobial Cyclic Dipeptides from Japanese Quail (Coturnix japonica) Eggs Supplemented with Probiotic Lactobacillus plantarum

Fifteen cyclic dipeptides (CDPs) containing proline, one cyclo(Phe-Ala) without proline, and a non-peptidyl DL-3-phenyllactic acid were previously identified in the culture filtrates of Lactobacillus plantarum LBP-K10, an isolate from kimchi. In this study, we used Japanese quail (Coturnix japonica) eggs to examine the effects of probiotic supplementation on the antimicrobial CDPs extracted from quail eggs (QE). Eggshell-free QE were obtained from two distinct groups of quails. The first group (K10N) comprised eggs from unsupplemented quails. The second group (K10S) comprised eggs from quails supplemented with Lb. plantarum LBP-K10. The QE samples were extracted using methylene chloride through a liquid-liquid extraction process. The resulting extract was fractionated into 16 parts using semi-preparative high-performance liquid chromatography. Two fractions, Q6 and Q9, were isolated from K10S and identified as cis-cyclo(L-Ser-L-Pro) and cis-cyclo(L-Leu-L-Pro). The Q9 fraction, containing cis-cyclo(L-Leu-L-Pro), has shown significant inhibitory properties against the proliferation of highly pathogenic multidrug-resistant bacteria, as well as human-specific and phytopathogenic fungi. Some of the ten combinations between the remaining fourteen unidentified fractions and two fractions, Q6 and Q9, containing cis-cyclo(L-Ser-L-Pro) and cis-cyclo(L-Leu-L-Pro) respectively, demonstrated a significant increase in activity against multidrug-resistant bacteria only when combined with Q9. The activity was 7.17 times higher compared to a single cis-cyclo(L-Leu-L-Pro). This study presents new findings on the efficacy of proline-containing CDPs in avian eggs. These CDPs provide antimicrobial properties when specific probiotics are supplemented.

From Beach to the Bedside: Harnessing Mitochondrial Function in Human Diseases Using New Marine-Derived Strategies

Mitochondria are double-membrane organelles within eukaryotic cells that act as cellular power houses owing to their ability to efficiently generate the ATP required to sustain normal cell function. Also, they represent a "hub" for the regulation of a plethora of processes, including cellular homeostasis, metabolism, the defense against oxidative stress, and cell death. Mitochondrial dysfunctions are associated with a wide range of human diseases with complex pathologies, including metabolic diseases, neurodegenerative disorders, and cancer. Therefore, regulating dysfunctional mitochondria represents a pivotal therapeutic opportunity in biomedicine. Marine ecosystems are biologically very diversified and harbor a broad range of organisms, providing both novel bioactive substances and molecules with meaningful biomedical and pharmacological applications. Recently, many mitochondria-targeting marine-derived molecules have been described to regulate mitochondrial biology, thus exerting therapeutic effects by inhibiting mitochondrial abnormalities, both in vitro and in vivo, through different mechanisms of action. Here, we review different strategies that are derived from marine organisms which modulate specific mitochondrial processes or mitochondrial molecular pathways and ultimately aim to find key molecules to treat a wide range of human diseases characterized by impaired mitochondrial function.

Antheraea proylei J. Sericin Induces Apoptosis in a Caspase-dependent Manner in A549 and HeLa Cells

BACKGROUND

In spite of much progress in cancer, the global cancer burden is still significant and increasing. Sericin, an adhesive protein of silk cocoons, has been shown to be a potential protein in various biomedical applications, including cancer therapeutics. The present study evaluates the anticancer property of sericin from cocoons of Antheraea proylei J (SAP) against human lung cancer (A549) and cervical cancer (HeLa) cell lines. This is the first report of anti-cancer activity of the non-mulberry silkworm A. proylei J.

OBJECTIVE

Establish the antiproliferative potential of SAP. 2. Identify the molecular mechanism of cell death induced by SAP on two different cell lines.

AIMS

To investigate the anticancer activity of sericin preparation from cocoons of A. proylei.

METHODS

SAP was prepared from cocoons of A. proylei J. by the process of the degumming method. Cytotoxic activity was assessed by MTT assay, and genotoxicity was assessed by comet assay. Cleavage of caspase and PARP proteins and phosphorylation of MAPK pathway members were analysed by Western blotting. Cell cycle analysis was done by flow cytometer.

RESULTS

SAP causes cytotoxicity to A549 and HeLa cell lines with the IC50 values 3.8 and 3.9 μg/μl respectively. SAP induces apoptosis in a dose-dependent manner through caspase-3 and p38, MAPK pathways in A549 and HeLa cells. Moreover, in A549 and HeLa cells, SAP induces cell cycle arrest at the S phase in a dose-dependent manner.

CONCLUSION

The difference in the molecular mechanisms of apoptosis induced by SAP in A549 and HeLa cell lines may be due to the difference in the genotypes of the cancer cell lines. However, further investigation is warranted. The overall results of the present study envisage the possibility of using SAP as an anti-tumorigenic agent.

Development and Challenges of Cyclic Peptides for Immunomodulation

Cyclic peptides are polypeptide chains formed by cyclic sequences of amide bonds between protein-derived or non-protein-derived amino acids. Compared to linear peptides, cyclic peptides offer several unique advantages, such as increased stability, stronger affinity, improved selectivity, and reduced toxicity. Cyclic peptide has been proved to have a promising application prospect in the medical field. In addition, this paper mainly describes that cyclic peptides play an important role in anti-cancer, anti-inflammatory, anti-virus, treatment of multiple sclerosis and membranous nephropathy through immunomodulation. In order to know more useful information about cyclic peptides in clinical research and drug application, this paper also summarizes cyclic peptides currently in the clinical trial stage and cyclic peptide drugs approved for marketing in the recent five years. Cyclic peptides have many advantages and great potential in treating various diseases, but there are still many challenges to be solved in the development process of cyclic peptides.

A Series of Planar Phosphorescent Cyclometalated Platinum(II) Complexes as New Anticancer Theranostic Agents That Induce Oncosis

Herein, four planar cyclometalated platinum(II) complexes with a main ligand of enlarged aromatic rings have been assessed as effective anticancer theranostic agents for the first time. With an increased number of aromatic rings in the N∧N ligand, 1a-1d exhibit increased lipophilicity and cytotoxicity selectivity. The intensity of the Pt-Pt interaction of each complex can be indicated by an enhanced near-infrared (NIR) emission in phosphate-buffered saline (PBS), their binding activity with biomolecules of bovine serum albumin (BSA) is accompanied by a vivid turn-on green emission, and the intensity gradually decreased from 1a to 1d, which is consistent with the docking of two complexes with BSA. Both "turn-on" NIR and green emission of 1d can be mainly observed in nuclei of living cell within 24 h, while two phosphorescence traces of 1b were recorded in lysosomes by confocal imaging. Moreover, 1d shows the highest efficiency in inducing oncosis of Hela cells, and the relative process was investigated.

Aquatic Peptide: The Potential Anti-Cancer and Anti-Microbial Activity of GE18 Derived from Pathogenic Fungus Aphanomyces invadans

Small molecules as well as peptide-based therapeutic approaches have attracted global interest due to their lower or no toxicity in nature, and their potential in addressing several health complications including immune diseases, cardiovascular diseases, metabolic disorders, osteoporosis and cancer. This study proposed a peptide, GE18 of subtilisin-like peptidase from the virulence factor of aquatic pathogenic fungus Aphanomyces invadans, which elicits anti-cancer and anti-microbial activities. To understand the potential GE18 peptide-induced biological effects, an in silico analysis, in vitro (L6 cells) and in vivo toxicity assays (using zebrafish embryo), in vitro anti-cancer assays and anti-microbial assays were performed. The outcomes of the in silico analyses demonstrated that the GE18 peptide has potent anti-cancer and anti-microbial activities. GE18 is non-toxic to in vitro non-cancerous cells and in vivo zebrafish larvae. However, the peptide showed significant anti-cancer properties against MCF-7 cells with an IC50 value of 35.34 µM, at 24 h. Besides the anti-proliferative effect on cancer cells, the peptide exposure does promote the ROS concentration, mitochondrial membrane potential and the subsequent upregulation of anti-cancer genes. On the other hand, GE18 elicits significant anti-microbial activity against P. aeruginosa, wherein GE18 significantly inhibits bacterial biofilm formation. Since the peptide has positively charged amino acid residues, it targets the cell membrane, as is evident in the FESEM analysis. Based on these outcomes, it is possible that the GE18 peptide is a significant anti-cancer and anti-microbial molecule.

PS9, Derived from an Aquatic Fungus Virulent Protein, Glycosyl Hydrolase, Arrests MCF-7 Proliferation by Regulating Intracellular Reactive Oxygen Species and Apoptotic Pathways

One of the most common diseases in women is breast cancer, which has the highest death globally. Surgery, chemotherapy, hormone treatments, and radiation are the current treatment options for breast cancer. However, these options have several adverse side effects. Recently, peptide-based drugs have gained attention as anticancer therapy. Studies report that peptides from biological toxins such as venom and virulent pathogenic molecules have potential therapeutic effects against multiple diseases, including cancers. This study reports on the in vitro anticancer effect of a short peptide, PS9, derived from a virulent protein, glycosyl hydrolase, of an aquatic fungus, Aphanomyces invadans. This peptide arrests MCF-7 proliferation by regulating intercellular reactive oxygen species (ROS) and apoptotic pathways. Based on the potential for the anticancer effect of PS9, from the in silico analysis, in vitro analyses using MCF-7 cells were executed. PS9 showed a dose-dependent activity; its IC50 value was 25.27-43.28 μM at 24 h. The acridine orange/ethidium bromide (AO/EtBr) staining, to establish the status of apoptosis in MCF-7 cells, showed morphologies for early and late apoptosis and necrotic cell death. The 2,7-dichlorodihydrofluorescein diacetate (DCFDA) staining and biochemical analyses showed a significant increase in reactive oxygen species (ROS). Besides, PS9 has been shown to regulate the caspase-mediated apoptotic pathway. PS9 is nontoxic, in vitro, and in vivo zebrafish larvae. Together, PS9 may have an anticancer effect in vitro.

Aidi injection enhances the anti-tumor impact of doxorubicin in H22 tumor-containing mice

ETHNOPHARMACOLOGICAL RELEVANCE

Aidi injection (AD) is a traditional medical preparation that has a Chinese origin. It is extensively used particularly in combination with doxorubicin (DOX) for the management of hepatocellular carcinoma (HCC). However, the combination's synergistic mechanism has not yet been clarified.

AIM OF THE STUDY

To investigate the anti-tumor impact of AD in combination with DOX and their synergistic mechanism in HCC.

MATERIALS AND METHODS

An H22 mouse xenograft model was utilized to study the impact of AD, DOX, and their combination on HCC in vivo. Their effects on cell vitality, apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS) production, caspase-3, and cleaved caspase-3 protein expression were also investigated in H22 cells in vitro. Subsequently, human umbilical vein endothelial cells (HUVECs) were utilized to investigate the impacts of AD, DOX, and their combination on cell viability, migration, invasion, tube formation, and vascular endothelial growth factor (VEGF) protein expression.

RESULTS

The study established that the tumor inhibition rate of AD combined with DOX reached 79.51%, which was significantly higher than that of AD (25.14%) or DOX (49.48%) alone. Additionally, the Q-value characterizing the synergy between AD and DOX was 1.72, demonstrating a strong synergistic effect. Furthermore, compared to AD or DOX administration alone, the combined administration group significantly decreased the alpha-fetoprotein (AFP) level in the serum, increased the tumor necrosis area, increased the Bax/Bcl-2, Cyt-c, caspase-9, Fas, Fasl, caspase-8, and caspase-3 protein expression, and significantly increased the CD31 and Ki67 protein expression in tumor tissue. Compared to AD or DOX alone, AD combined with DOX treatment had a synergistic effect on H22 cells (combination index values < 0.9), which inhibited cell viability, reduced mitochondrial membrane potential (MMP), induced apoptosis, promoted MMP loss, and increased ROS generation, cleaved caspase-3/caspase-3 levels, and caspase-3 activity. Moreover, combined administration showed a more pronounced inhibition of cell viability, migration, invasion, tube formation, and VEGF protein expression in HUVECs.

CONCLUSIONS

AD enhances the anti-tumor effect of DOX by promoting apoptosis and inhibiting angiogenesis and cell proliferation. The findings of this study lay experimental foundations for the clinical combination of AD and DOX.

Anti-Cancer and Anti-Inflammatory Activities of a Short Molecule, PS14 Derived from the Virulent Cellulose Binding Domain of Aphanomyces invadans, on Human Laryngeal Epithelial Cells and an In Vivo Zebrafish Embryo Model

In this study, the anti-cancer and anti-inflammatory activities of PS14, a short peptide derived from the cellulase binding domain of pathogenic fungus, Aphanomyces invadans, have been evaluated, in vitro and in vivo. Bioinformatics analysis of PS14 revealed the physicochemical properties and the web-based predictions, which indicate that PS14 is non-toxic, and it has the potential to elicit anti-cancer and anti-inflammatory activities. These in silico results were experimentally validated through in vitro (L6 or Hep-2 cells) and in vivo (zebrafish embryo or larvae) models. Experimental results showed that PS14 is non-toxic in L6 cells and the zebrafish embryo, and it elicits an antitumor effect Hep-2 cells and zebrafish embryos. Anticancer activity assays, in terms of MTT, trypan blue and LDH assays, showed a dose-dependent inhibitory effect on cell proliferation. Moreover, in the epithelial cancer cells and zebrafish embryos, the peptide challenge (i) caused significant changes in the cytomorphology and induced apoptosis; (ii) triggered ROS generation; and (iii) showed a significant up-regulation of anti-cancer genes including BAX, Caspase 3, Caspase 9 and down-regulation of Bcl-2, in vitro. The anti-inflammatory activity of PS14 was observed in the cell-free in vitro assays for the inhibition of proteinase and lipoxygenase, and heat-induced hemolysis and hypotonicity-induced hemolysis. Together, this study has identified that PS14 has anti-cancer and anti-inflammatory activities, while being non-toxic, in vitro and in vivo. Future experiments can focus on the clinical or pharmacodynamics aspects of PS14.

Marine Compounds, Mitochondria, and Malignancy: A Therapeutic Nexus

The marine environment is important yet generally underexplored. It contains new sources of functional constituents that can affect various pathways in food processing, storage, and fortification. Bioactive secondary metabolites produced by marine microorganisms may have significant potential applications for humans. Various components isolated from disparate marine microorganisms, including fungi, microalgae, bacteria, and myxomycetes, showed considerable biological effects, such as anticancer, antioxidant, antiviral, antibacterial, and neuroprotective activities. Growing studies are revealing that potential anticancer effects of marine agents could be achieved through the modulation of several organelles. Mitochondria are known organelles that influence growth, differentiation, and death of cells via influencing the biosynthetic, bioenergetic, and various signaling pathways related to oxidative stress and cellular metabolism. Consequently, mitochondria play an essential role in tumorigenesis and cancer treatments by adapting to alterations in environmental and cellular conditions. The growing interest in marine-derived anticancer agents, combined with the development and progression of novel technology in the extraction and cultures of marine life, led to revelations of new compounds with meaningful pharmacological applications. This is the first critical review on marine-derived anticancer agents that have the potential for targeting mitochondrial function during tumorigenesis. This study aims to provide promising strategies in cancer prevention and treatment.

Potential anticancer effects of cyclo(-Pro-Tyr) against N-diethyl nitrosamine induced hepatocellular carcinoma in mouse through PI3K/AKT signaling

The oceans are considered as magnificent source of bioactive metabolites, of which marine sponges associated organisms are being the most effective producers of various bioactive molecules. We previously reported that cyclo(-Pro-Tyr) (CPT), a dipeptide from marine sponge Callyspongia fistularis associated Bacillus pumilus AMK1 bacteria for its anti-proliferative activity through down regulating PI3K signaling and inducing mitochondrial mediated apoptosis in HepG2 cells. Further we emphasize to study the role of CPT against hepatocellular carcinoma (HCC) induced by N-diethylnitrosamine (DEN) in male swiss albino mice in vivo. In this study, HCC was induced by the administration of DEN (75 mg/kg b.wt) dissolved in saline once/week for 3 weeks, then 100 mg/kg b.wt for another successive 3 weeks and observed for 18 weeks. CPT (100 mg/kg b.wt) treatment was started after 14 weeks of DEN induction. The obtained results demonstrated that CPT altered DEN induced oxidative stress by decreasing serum SGOT and SGPT followed increment in the antioxidants such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. This was accompanied by decreased accumulation of glycoconjugates and argyophilic nucleolar organizing regions in the treatment groups. Further, CPT significantly reduced the levels of phospho-PI3Kinase p85 and phospho-AKT and upregulation of PTEN compared with DEN induced group. Besides this, decreased expression of Bcl-2 and increased expression of Bax, Caspase 3, and p53 was observed in CPT treated mice. Therefore, the anticancer mechanism of CPT against DEN induced HCC may be associated with the regulation of the PI3K/AKT signaling pathway, which ultimately stimulates apoptosis.

Investigation on the mechanisms of biochanin A alleviate PM10-induced acute pulmonary cell injury

Epidemiological studies have shown that the elevated concentration of particulate matter with aerodynamic diameter less than 10 µm (PM10) is closely related to the increased risk of heart and lung diseases in the population. Natural isoflavone compound biochanin A (BCA) has anti-inflammatory and antioxidant activities, and has efficacy in alleviating lung injury. The objective of this study was to investigate the inhibitory effect of BCA on PM10 induced acute human bronchial epithelial cells injury. The results showed that PM10 decreased intracellular catalase level to 1.19 ± 0.01 nmol/min/mg prot and induce a surge of reactive oxygen species (ROS). It also increased lactate dehydrogenase (LDH) activity by 428.89% and caused the lipid peroxidation phenomenon. PM10 exposure also upregulates the expression of inflammatory cytokines and mediators. However, BCA could interfere with the above changes caused by PM10, inhibit the LDH level to 8.22 ± 0.03 u/mL, and show anti-inflammatory and antioxidant activities. In addition, the phosphatidylinositol 3-kimase (PI3K) /protein kinase B (PKB/Akt) is a key signal pathway in response to PM10 exposure. In this study, PI3K/Akt signaling pathway is seriously affected by PM10 exposure. PI3K/Akt signaling pathway, PI3K, AKT, tensin homolog deleted on chromosome 10 (PTEN), mechanistic target of rapamycin (mTOR) and p53 protein were all inhibited by PM10 exposure, and PI3K/Akt signaling pathway was inactivated. BCA exert anti-damage function by regulating the activation process of PI3K protein, intervening the regulation process of PI3K/Akt by PTEN, and intervening the expression and phosphorylation of downstream Akt protein.

Recent developments on production, purification and biological activity of marine peptides

Marine peptides are one of the richest sources of structurally diverse bioactive compounds and a considerable attention has been drawn towards their production and bioactivity. However, there is a paucity in consolidation of emerging trends encompassing both production techniques and biological application. Herein, we intend to review the recent advancements on different production, purification and identification technologies used for marine peptides along with presenting their potential health benefits. Bibliometric analysis revealed a growing number of scientific publications on marine peptides (268 documents per year) with both Asia (37.2%) and Europe (33.1%) being the major contributors. Extraction and purification by ultrafiltration and enzymatic hydrolysis, followed by identification by chromatographic techniques coupled with an appropriate detector could yield a high content of peptides with improved bioactivity. Moreover, the multifunctional health benefits exerted by marine peptides including anti-microbial, antioxidant, anti-hypertension, anti-diabetes and anti-cancer along with their structure-activity relationship were presented. The future perspective on marine peptide research should focus on finding improved separation and purification technologies with enhanced selectivity and resolution for obtaining more novel peptides with high yield and low cost. In addition, by employing encapsulation strategies such as nanoemulsion and nanoliposome, oral bioavailability and bioactivity of peptides can be greatly enhanced. Also, the potential health benefits that are demonstrated by in vitro and in vivo models should be validated by conducting human clinical trials for a technology transfer from bench to bedside.

Antitumor Effects of a Sesquiterpene Derivative from Marine Sponge in Human Breast Cancer Cells

In this study, the anti-proliferative effect of ilimaquinone, a sesquiterpene derivative from the marine sponge, in breast cancer cells was investigated. Ilimaquinone inhibited the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC₅₀ values of 10.6 μM and 13.5 μM, respectively. Non-tumorigenic human breast epithelial cells were less sensitive to ilimaquinone than breast cancer cells. Flow cytometric and Western blot analysis showed that ilimaquinone induced S-phase arrest by modulating the expression of p-CDC-2 and p21. Ilimaquinone induces apoptosis, which is accompanied by multiple biological biomarkers, including the downregulation of Akt, ERK, and Bax, upregulation of p38, loss of mitochondrial membrane potential, increased reactive oxygen species generation, and induced autophagy. Collectively, these findings suggest that ilimaquinone causes cell cycle arrest as well as induces apoptosis and autophagy in breast cancer cells.

Targeting signal pathways triggered by cyclic peptides in cancer: Current trends and future challenges

Cancer is a global health issue that origins thousands of deaths annually worldwide. Cyclic peptides are polypeptide chains which are formed by cyclic sequence of amide bonds between proteinogenic or non-proteinogenic amino acids. Numerous evidences indicate that cyclic peptides are implicated with the occurrence and development of cancer. This review presents the current knowledge about the role of cyclic peptides in cancer, such as liver cancer, colorectal cancer, ovarian cancer, breast cancer as well as prostate cancer. Specifically, the precise molecular mechanisms between cyclic peptides and cancer are elaborated. Some cyclic peptides from nature and synthesis prevent the occurrence and development of cancer. However, some other cyclic peptides including endothelin-1, urotensinⅡand melanin-concentrating hormone deteriorate the pathogenesis of cancer. Given the pleiotropic actions of cyclic peptides, the identification and development of cyclic peptides and their derivates as drug may be a potent therapeutic strategy for cancer.